Sports Medicine

The Orthopaedic Sports Medicine Fellowship Match was first established in 2008 as a joint-sponsored venture between the American Orthopaedic Society for Sports Medicine and the Arthroscopy Association of North America to pair applicants with participating training programs.¹ Operated under the San Francisco Match,² the current fellowship match process was adopted to systematically coordinate training appointments and eliminate the role of “exploding offers,” which are pressured early decisions predicated on immediate acceptance. Other advantages of this system include its operation through a central application service to avoid redundancy of submitted paperwork, as well as to create greater awareness and to publicize training options and standardization of the match timeline.¹

In its current state, the orthopedic sports medicine match represents 96 programs with 230 positions, accounting for approximately 97% of training programs and fellowship positions.¹ While unaccredited options remain available through the Match, many programs have migrated towards American Council for Graduate Medical Education (ACGME) accreditation because of an increased focus on objective learning metrics during fellowship and the requirement for Subspecialty Certification in Orthopaedic Sports Medicine through the American Board of Orthopaedic Surgery.³ However, other programs have also eschewed the increasing constraints and administrative resources associated with ACGME accreditation, particularly among fellowships based at community-based hospitals or private practices that lack formal affiliation with academic institutions or residency training programs.

Along with a greater understanding of the historical background of the match process, fellowship applicants must also appreciate the relative merits of fellowship training. More than 90% of orthopedic surgery residents now pursue further subspecialty fellowship training, with some individuals opting for 2 additional fellowship opportunities.⁴ As a so-called “nontraditional applicant,” I represent a different demographic, returning to fellowship after years of clinical practice while serving in the military. Individual preferences notwithstanding, I wanted to take the opportunity to emphasize some important considerations in deliberating between different fellowship programs.

• Geography. Your eventual desired practice location may play a role in determining fellowship location or, at least, region of the country. Additionally, this can be an important factor in family happiness. In competitive markets, such as the Northeast or the West Coast, you may make inroads and establish professional connections that result in potential job opportunities. Conversely, other programs may adopt anticompetitive measures to limit local practice options.
• Training setting. Despite the trending consolidation of fellowship training programs in affiliated university and hospital-based teaching systems, many community-based programs and private-practice models thrive, providing an alternative to traditional academic training centers. The latter may provide more in-depth exposure to practice management, billing/coding, and ancillary services. The former typically offer a more structured, academically oriented environment with formal teaching conferences and a broader department hierarchy.
• Program size. Some applicants may prefer a larger, more diverse array of teaching staff or fellows, while others gravitate toward fewer, more personal mentoring relationships that allow more intimate familiarity with practice habits or surgical techniques.
• Associated training programs. Affiliations with a residency or physician-extender training program can offer benefits and drawbacks, including offloading clerical work, shared hands-on experience in the clinic and operating room, and midlevel supervisory responsibilities. This can offer useful opportunities to formulate an individual teaching style and valuable mentoring relationships. However, it can also impose greater time requirements or detract from one-on-one teaching with staff.
• Reputation. Applicants may attach distinction to a well-established regional or national reputation associated with a given training program. Often, certain programs may carry prestige as a result of their academic name, hospital affiliation, or accomplishments. This can offer certain marketing advantages for patient recruitment. However, less renowned programs may provide better training opportunities and confer higher esteem among your professional colleagues. Program reputation can change dramatically with time, so this should be balanced with other potential strengths and overall training experience.
• Practice “niches”/areas of interest. With increasing adoption of arthroscopic techniques among practicing surgeons and a relative excess of sports medicine–trained orthopedists, it is paramount to develop a novel skill set during fellowship to differentiate you from other graduates. I sought a sports medicine fellowship that would offer me a broad-based exposure to arthroscopic and open knee and shoulder reconstruction, chondral restoration techniques, hip arthroscopy and preservation, and shoulder arthroplasty. Opportunities in elbow reconstruction, foot and ankle arthroscopy, and pediatric sports medicine may also be valuable as a distinguishing factor in searching for jobs after training.
• Marketability. Closely intertwined with reputation and scope of practice, an institution’s marketability is another intangible attribute to consider. Professional or collegiate team coverage offers significant market value for patient advertising, and it is frequently publicized by orthopedic practices and hospital systems. Additionally, the importance of ACGME accreditation should also be considered.
• Nonmedical training. This is increasingly important in subsequent subspecialty training. Further education on the business aspects of orthopedic surgery should be emphasized. Additionally, dedicated curricula on professional or leadership development are important for career progression.
• Mentorship. Throughout the interview process, one of my foremost priorities was a strong and enduring pattern of mentorship. Fellowship offers the opportunity to establish 1 or multiple mentors in your subspecialty. These individuals will be instrumental in the development of your early professional career and your approach to clinical practice. From discussions about complicated patients to advice on contract negotiations, your ideal mentor should champion your early successes and work generously on your behalf, even long after fellowship has ended. 

• Research opportunities. Given my academic career goals, I actively pursued a program with rich clinical and laboratory resources, and an established infrastructure for accomplishing high-quality, relevant research. Interested individuals should gauge the availability of research support staff, biomechanical or bench-level laboratory collaboration, grant or institutional research funding, cadaveric specimens, or clinical outcomes data for research conducted by fellows. However, not all fellowship applicants have a vested interest in research during fellowship, so I would encourage inquiries regarding core research requirements and expectations.
• Clinical exposure. This encompasses several different and equally important variables, including diversity of clinical or surgical caseloads, case complexity, operative exposure, athletic team coverage, and office or clinical experience. Interestingly, this latter aspect of training is often neglected but cannot be overemphasized. Outpatient clinical evaluation is key to honing important physical examination techniques and critically evaluating patients’ outcomes postoperatively.
• Surgical autonomy. Hands-on operative experience and surgical autonomy vary widely among fellowship programs. Most fellowships advocate for a graduated level of surgical responsibility dependent on individual abilities and staff comfort, while others offer greater potential for independence. Conversely, some programs espouse more of an “observership” model, and arthroscopic simulators and/or cadaveric skills laboratories are designed to complement operative experience. While most fellowship applicants desire maximal case participation, we must also recognize the value in watching talented surgeons performing technically demanding procedures.
• Family. You cannot put a premium on your personal contentment and family’s well-being. Proximity to a support network can be important with the work demands and time constraints of fellowship.

 

Despite financial obligations and significant time commitments, the fellowship match process offers an incredible range of programs and practice environments. Inevitably, no program can completely fulfill all your criteria, but you should be able to tailor your learning style, professional ambitions, and personal preferences with an excellent training program. For many, fellowship represents the last, and perhaps most integral, stage of formal surgical training. Considering all factors of your chosen fellowship program will ensure a rich and fulfilling educational experience.

The Orthopaedic Sports Medicine Fellowship Match was first established in 2008 as a joint-sponsored venture between the American Orthopaedic Society for Sports Medicine and the Arthroscopy Association of North America to pair applicants with participating training programs.¹ Operated under the San Francisco Match,² the current fellowship match process was adopted to systematically coordinate training appointments and eliminate the role of “exploding offers,” which are pressured early decisions predicated on immediate acceptance. Other advantages of this system include its operation through a central application service to avoid redundancy of submitted paperwork, as well as to create greater awareness and to publicize training options and standardization of the match timeline.¹

In its current state, the orthopedic sports medicine match represents 96 programs with 230 positions, accounting for approximately 97% of training programs and fellowship positions.¹ While unaccredited options remain available through the Match, many programs have migrated towards American Council for Graduate Medical Education (ACGME) accreditation because of an increased focus on objective learning metrics during fellowship and the requirement for Subspecialty Certification in Orthopaedic Sports Medicine through the American Board of Orthopaedic Surgery.³ However, other programs have also eschewed the increasing constraints and administrative resources associated with ACGME accreditation, particularly among fellowships based at community-based hospitals or private practices that lack formal affiliation with academic institutions or residency training programs.

Along with a greater understanding of the historical background of the match process, fellowship applicants must also appreciate the relative merits of fellowship training. More than 90% of orthopedic surgery residents now pursue further subspecialty fellowship training, with some individuals opting for 2 additional fellowship opportunities.⁴ As a so-called “nontraditional applicant,” I represent a different demographic, returning to fellowship after years of clinical practice while serving in the military. Individual preferences notwithstanding, I wanted to take the opportunity to emphasize some important considerations in deliberating between different fellowship programs.

• Geography. Your eventual desired practice location may play a role in determining fellowship location or, at least, region of the country. Additionally, this can be an important factor in family happiness. In competitive markets, such as the Northeast or the West Coast, you may make inroads and establish professional connections that result in potential job opportunities. Conversely, other programs may adopt anticompetitive measures to limit local practice options.
• Training setting. Despite the trending consolidation of fellowship training programs in affiliated university and hospital-based teaching systems, many community-based programs and private-practice models thrive, providing an alternative to traditional academic training centers. The latter may provide more in-depth exposure to practice management, billing/coding, and ancillary services. The former typically offer a more structured, academically oriented environment with formal teaching conferences and a broader department hierarchy.
• Program size. Some applicants may prefer a larger, more diverse array of teaching staff or fellows, while others gravitate toward fewer, more personal mentoring relationships that allow more intimate familiarity with practice habits or surgical techniques.
• Associated training programs. Affiliations with a residency or physician-extender training program can offer benefits and drawbacks, including offloading clerical work, shared hands-on experience in the clinic and operating room, and midlevel supervisory responsibilities. This can offer useful opportunities to formulate an individual teaching style and valuable mentoring relationships. However, it can also impose greater time requirements or detract from one-on-one teaching with staff.
• Reputation. Applicants may attach distinction to a well-established regional or national reputation associated with a given training program. Often, certain programs may carry prestige as a result of their academic name, hospital affiliation, or accomplishments. This can offer certain marketing advantages for patient recruitment. However, less renowned programs may provide better training opportunities and confer higher esteem among your professional colleagues. Program reputation can change dramatically with time, so this should be balanced with other potential strengths and overall training experience.
• Practice “niches”/areas of interest. With increasing adoption of arthroscopic techniques among practicing surgeons and a relative excess of sports medicine–trained orthopedists, it is paramount to develop a novel skill set during fellowship to differentiate you from other graduates. I sought a sports medicine fellowship that would offer me a broad-based exposure to arthroscopic and open knee and shoulder reconstruction, chondral restoration techniques, hip arthroscopy and preservation, and shoulder arthroplasty. Opportunities in elbow reconstruction, foot and ankle arthroscopy, and pediatric sports medicine may also be valuable as a distinguishing factor in searching for jobs after training.
• Marketability. Closely intertwined with reputation and scope of practice, an institution’s marketability is another intangible attribute to consider. Professional or collegiate team coverage offers significant market value for patient advertising, and it is frequently publicized by orthopedic practices and hospital systems. Additionally, the importance of ACGME accreditation should also be considered.
• Nonmedical training. This is increasingly important in subsequent subspecialty training. Further education on the business aspects of orthopedic surgery should be emphasized. Additionally, dedicated curricula on professional or leadership development are important for career progression.
• Mentorship. Throughout the interview process, one of my foremost priorities was a strong and enduring pattern of mentorship. Fellowship offers the opportunity to establish 1 or multiple mentors in your subspecialty. These individuals will be instrumental in the development of your early professional career and your approach to clinical practice. From discussions about complicated patients to advice on contract negotiations, your ideal mentor should champion your early successes and work generously on your behalf, even long after fellowship has ended. 

• Research opportunities. Given my academic career goals, I actively pursued a program with rich clinical and laboratory resources, and an established infrastructure for accomplishing high-quality, relevant research. Interested individuals should gauge the availability of research support staff, biomechanical or bench-level laboratory collaboration, grant or institutional research funding, cadaveric specimens, or clinical outcomes data for research conducted by fellows. However, not all fellowship applicants have a vested interest in research during fellowship, so I would encourage inquiries regarding core research requirements and expectations.
• Clinical exposure. This encompasses several different and equally important variables, including diversity of clinical or surgical caseloads, case complexity, operative exposure, athletic team coverage, and office or clinical experience. Interestingly, this latter aspect of training is often neglected but cannot be overemphasized. Outpatient clinical evaluation is key to honing important physical examination techniques and critically evaluating patients’ outcomes postoperatively.
• Surgical autonomy. Hands-on operative experience and surgical autonomy vary widely among fellowship programs. Most fellowships advocate for a graduated level of surgical responsibility dependent on individual abilities and staff comfort, while others offer greater potential for independence. Conversely, some programs espouse more of an “observership” model, and arthroscopic simulators and/or cadaveric skills laboratories are designed to complement operative experience. While most fellowship applicants desire maximal case participation, we must also recognize the value in watching talented surgeons performing technically demanding procedures.
• Family. You cannot put a premium on your personal contentment and family’s well-being. Proximity to a support network can be important with the work demands and time constraints of fellowship.

 

Despite financial obligations and significant time commitments, the fellowship match process offers an incredible range of programs and practice environments. Inevitably, no program can completely fulfill all your criteria, but you should be able to tailor your learning style, professional ambitions, and personal preferences with an excellent training program. For many, fellowship represents the last, and perhaps most integral, stage of formal surgical training. Considering all factors of your chosen fellowship program will ensure a rich and fulfilling educational experience.

The Orthopaedic Sports Medicine Fellowship Match was first established in 2008 as a joint-sponsored venture between the American Orthopaedic Society for Sports Medicine and the Arthroscopy Association of North America to pair applicants with participating training programs.¹ Operated under the San Francisco Match,² the current fellowship match process was adopted to systematically coordinate training appointments and eliminate the role of “exploding offers,” which are pressured early decisions predicated on immediate acceptance. Other advantages of this system include its operation through a central application service to avoid redundancy of submitted paperwork, as well as to create greater awareness and to publicize training options and standardization of the match timeline.¹

In its current state, the orthopedic sports medicine match represents 96 programs with 230 positions, accounting for approximately 97% of training programs and fellowship positions.¹ While unaccredited options remain available through the Match, many programs have migrated towards American Council for Graduate Medical Education (ACGME) accreditation because of an increased focus on objective learning metrics during fellowship and the requirement for Subspecialty Certification in Orthopaedic Sports Medicine through the American Board of Orthopaedic Surgery.³ However, other programs have also eschewed the increasing constraints and administrative resources associated with ACGME accreditation, particularly among fellowships based at community-based hospitals or private practices that lack formal affiliation with academic institutions or residency training programs.

Along with a greater understanding of the historical background of the match process, fellowship applicants must also appreciate the relative merits of fellowship training. More than 90% of orthopedic surgery residents now pursue further subspecialty fellowship training, with some individuals opting for 2 additional fellowship opportunities.⁴ As a so-called “nontraditional applicant,” I represent a different demographic, returning to fellowship after years of clinical practice while serving in the military. Individual preferences notwithstanding, I wanted to take the opportunity to emphasize some important considerations in deliberating between different fellowship programs.

• Geography. Your eventual desired practice location may play a role in determining fellowship location or, at least, region of the country. Additionally, this can be an important factor in family happiness. In competitive markets, such as the Northeast or the West Coast, you may make inroads and establish professional connections that result in potential job opportunities. Conversely, other programs may adopt anticompetitive measures to limit local practice options.
• Training setting. Despite the trending consolidation of fellowship training programs in affiliated university and hospital-based teaching systems, many community-based programs and private-practice models thrive, providing an alternative to traditional academic training centers. The latter may provide more in-depth exposure to practice management, billing/coding, and ancillary services. The former typically offer a more structured, academically oriented environment with formal teaching conferences and a broader department hierarchy.
• Program size. Some applicants may prefer a larger, more diverse array of teaching staff or fellows, while others gravitate toward fewer, more personal mentoring relationships that allow more intimate familiarity with practice habits or surgical techniques.
• Associated training programs. Affiliations with a residency or physician-extender training program can offer benefits and drawbacks, including offloading clerical work, shared hands-on experience in the clinic and operating room, and midlevel supervisory responsibilities. This can offer useful opportunities to formulate an individual teaching style and valuable mentoring relationships. However, it can also impose greater time requirements or detract from one-on-one teaching with staff.
• Reputation. Applicants may attach distinction to a well-established regional or national reputation associated with a given training program. Often, certain programs may carry prestige as a result of their academic name, hospital affiliation, or accomplishments. This can offer certain marketing advantages for patient recruitment. However, less renowned programs may provide better training opportunities and confer higher esteem among your professional colleagues. Program reputation can change dramatically with time, so this should be balanced with other potential strengths and overall training experience.
• Practice “niches”/areas of interest. With increasing adoption of arthroscopic techniques among practicing surgeons and a relative excess of sports medicine–trained orthopedists, it is paramount to develop a novel skill set during fellowship to differentiate you from other graduates. I sought a sports medicine fellowship that would offer me a broad-based exposure to arthroscopic and open knee and shoulder reconstruction, chondral restoration techniques, hip arthroscopy and preservation, and shoulder arthroplasty. Opportunities in elbow reconstruction, foot and ankle arthroscopy, and pediatric sports medicine may also be valuable as a distinguishing factor in searching for jobs after training.
• Marketability. Closely intertwined with reputation and scope of practice, an institution’s marketability is another intangible attribute to consider. Professional or collegiate team coverage offers significant market value for patient advertising, and it is frequently publicized by orthopedic practices and hospital systems. Additionally, the importance of ACGME accreditation should also be considered.
• Nonmedical training. This is increasingly important in subsequent subspecialty training. Further education on the business aspects of orthopedic surgery should be emphasized. Additionally, dedicated curricula on professional or leadership development are important for career progression.
• Mentorship. Throughout the interview process, one of my foremost priorities was a strong and enduring pattern of mentorship. Fellowship offers the opportunity to establish 1 or multiple mentors in your subspecialty. These individuals will be instrumental in the development of your early professional career and your approach to clinical practice. From discussions about complicated patients to advice on contract negotiations, your ideal mentor should champion your early successes and work generously on your behalf, even long after fellowship has ended. 

• Research opportunities. Given my academic career goals, I actively pursued a program with rich clinical and laboratory resources, and an established infrastructure for accomplishing high-quality, relevant research. Interested individuals should gauge the availability of research support staff, biomechanical or bench-level laboratory collaboration, grant or institutional research funding, cadaveric specimens, or clinical outcomes data for research conducted by fellows. However, not all fellowship applicants have a vested interest in research during fellowship, so I would encourage inquiries regarding core research requirements and expectations.
• Clinical exposure. This encompasses several different and equally important variables, including diversity of clinical or surgical caseloads, case complexity, operative exposure, athletic team coverage, and office or clinical experience. Interestingly, this latter aspect of training is often neglected but cannot be overemphasized. Outpatient clinical evaluation is key to honing important physical examination techniques and critically evaluating patients’ outcomes postoperatively.
• Surgical autonomy. Hands-on operative experience and surgical autonomy vary widely among fellowship programs. Most fellowships advocate for a graduated level of surgical responsibility dependent on individual abilities and staff comfort, while others offer greater potential for independence. Conversely, some programs espouse more of an “observership” model, and arthroscopic simulators and/or cadaveric skills laboratories are designed to complement operative experience. While most fellowship applicants desire maximal case participation, we must also recognize the value in watching talented surgeons performing technically demanding procedures.
• Family. You cannot put a premium on your personal contentment and family’s well-being. Proximity to a support network can be important with the work demands and time constraints of fellowship.

 

Despite financial obligations and significant time commitments, the fellowship match process offers an incredible range of programs and practice environments. Inevitably, no program can completely fulfill all your criteria, but you should be able to tailor your learning style, professional ambitions, and personal preferences with an excellent training program. For many, fellowship represents the last, and perhaps most integral, stage of formal surgical training. Considering all factors of your chosen fellowship program will ensure a rich and fulfilling educational experience.

Point-of-care (POC) ultrasound is a great adjunct to the evaluation and treatment of shoulder dislocations. This modality can assist with identification of the dislocation—especially posterior dislocations, which can be notoriously difficult to diagnose on plain radiography.^1,2 Moreover, it can aid with reduction by guiding intra-articular anesthetic injection, regional anesthesia with an interscalene brachial plexus nerve block, or suprascapular nerve block. Following treatment, POC ultrasound also can immediately confirm successful reduction.

Imaging Technique

Since the shoulder joint is a deep structure, ultrasound should be performed using the lower frequency curvilinear probe. The probe should be positioned in the transverse orientation, behind the shoulder and over the scapular spine (Figure 1). The probe is then moved laterally to identify the glenoid; after the glenoid is visualized, the probe is moved further to locate the humeral head and determine its relationship to the glenoid. If the shoulder joint is immediately adjacent to glenoid, then it is in the appropriate anatomical position (Figure 2). If the humeral head is located in the near field of the image above the glenoid on the ultrasound screen, then a posterior dislocation is present—ie, since the probe is touching the posterior shoulder, the top of the screen represents posterior structures and the bottom of the screen represents anterior structures (Figure 3). If the humeral head is below the glenoid in the far field of the image, then the shoulder is anteriorly dislocated (Figure 4). A hyperechoic hemarthrosis is often seen in the joint when shoulder is anteriorly dislocated.

Facilitation of Reduction

Ultrasound-guided intra-articular joint injection is a simple and effective technique to deliver anesthesia to the shoulder.³ Imaging is performed with the same curvilinear probe using sterile precautions—ie, sterile probe and cord cover, sterile gloves, and skin prepped with chlorhexidine. To access the shoulder joint, a long needle, such as a spinal needle, is utilized to deliver a short-acting local anesthetic (eg, 1% lidocaine). It is essential to line up the probe marker with the screen marker to facilitate needle placement and adjustment. The spinal needle is inserted into the lateral deltoid, beneath the acromion and a few centimeters from the edge of the probe. It is then directed by ultrasound in real-time toward the hemarthrosis. Once the needle is within the joint, fluid should be aspirated to confirm return of blood and inject 20 cc of lidocaine (Figure 5). A video demonstrating this technique may be accessed online at https://vimeo.com/156762428. Before performing the reduction technique of choice, the clinician should wait 10 to 15 minutes for the joint injection to take effect.

Summary

Bedside ultrasound is an excellent adjunct to traditional radiographs in the evaluation of patients presenting with shoulder injuries. In addition to its high sensitivity in detecting dislocation, this modality can be used to guide intra-articular treatment and to confirm successful reduction.

---

Dr Meer is an assistant professor and director of emergency ultrasound, department of emergency medicine, Emory University School of Medicine, Atlanta. Dr Beck is an assistant professor, department of emergency medicine, Emory University School of Medicine, Atlanta. Dr Taylor is an assistant professor and director of postgraduate medical education, department of emergency medicine, Emory University School of Medicine, Atlanta.

Point-of-care (POC) ultrasound is a great adjunct to the evaluation and treatment of shoulder dislocations. This modality can assist with identification of the dislocation—especially posterior dislocations, which can be notoriously difficult to diagnose on plain radiography.^1,2 Moreover, it can aid with reduction by guiding intra-articular anesthetic injection, regional anesthesia with an interscalene brachial plexus nerve block, or suprascapular nerve block. Following treatment, POC ultrasound also can immediately confirm successful reduction.

Imaging Technique

Since the shoulder joint is a deep structure, ultrasound should be performed using the lower frequency curvilinear probe. The probe should be positioned in the transverse orientation, behind the shoulder and over the scapular spine (Figure 1). The probe is then moved laterally to identify the glenoid; after the glenoid is visualized, the probe is moved further to locate the humeral head and determine its relationship to the glenoid. If the shoulder joint is immediately adjacent to glenoid, then it is in the appropriate anatomical position (Figure 2). If the humeral head is located in the near field of the image above the glenoid on the ultrasound screen, then a posterior dislocation is present—ie, since the probe is touching the posterior shoulder, the top of the screen represents posterior structures and the bottom of the screen represents anterior structures (Figure 3). If the humeral head is below the glenoid in the far field of the image, then the shoulder is anteriorly dislocated (Figure 4). A hyperechoic hemarthrosis is often seen in the joint when shoulder is anteriorly dislocated.

Facilitation of Reduction

Ultrasound-guided intra-articular joint injection is a simple and effective technique to deliver anesthesia to the shoulder.³ Imaging is performed with the same curvilinear probe using sterile precautions—ie, sterile probe and cord cover, sterile gloves, and skin prepped with chlorhexidine. To access the shoulder joint, a long needle, such as a spinal needle, is utilized to deliver a short-acting local anesthetic (eg, 1% lidocaine). It is essential to line up the probe marker with the screen marker to facilitate needle placement and adjustment. The spinal needle is inserted into the lateral deltoid, beneath the acromion and a few centimeters from the edge of the probe. It is then directed by ultrasound in real-time toward the hemarthrosis. Once the needle is within the joint, fluid should be aspirated to confirm return of blood and inject 20 cc of lidocaine (Figure 5). A video demonstrating this technique may be accessed online at https://vimeo.com/156762428. Before performing the reduction technique of choice, the clinician should wait 10 to 15 minutes for the joint injection to take effect.

Summary

Bedside ultrasound is an excellent adjunct to traditional radiographs in the evaluation of patients presenting with shoulder injuries. In addition to its high sensitivity in detecting dislocation, this modality can be used to guide intra-articular treatment and to confirm successful reduction.

---

Dr Meer is an assistant professor and director of emergency ultrasound, department of emergency medicine, Emory University School of Medicine, Atlanta. Dr Beck is an assistant professor, department of emergency medicine, Emory University School of Medicine, Atlanta. Dr Taylor is an assistant professor and director of postgraduate medical education, department of emergency medicine, Emory University School of Medicine, Atlanta.

Point-of-care (POC) ultrasound is a great adjunct to the evaluation and treatment of shoulder dislocations. This modality can assist with identification of the dislocation—especially posterior dislocations, which can be notoriously difficult to diagnose on plain radiography.^1,2 Moreover, it can aid with reduction by guiding intra-articular anesthetic injection, regional anesthesia with an interscalene brachial plexus nerve block, or suprascapular nerve block. Following treatment, POC ultrasound also can immediately confirm successful reduction.

Imaging Technique

Since the shoulder joint is a deep structure, ultrasound should be performed using the lower frequency curvilinear probe. The probe should be positioned in the transverse orientation, behind the shoulder and over the scapular spine (Figure 1). The probe is then moved laterally to identify the glenoid; after the glenoid is visualized, the probe is moved further to locate the humeral head and determine its relationship to the glenoid. If the shoulder joint is immediately adjacent to glenoid, then it is in the appropriate anatomical position (Figure 2). If the humeral head is located in the near field of the image above the glenoid on the ultrasound screen, then a posterior dislocation is present—ie, since the probe is touching the posterior shoulder, the top of the screen represents posterior structures and the bottom of the screen represents anterior structures (Figure 3). If the humeral head is below the glenoid in the far field of the image, then the shoulder is anteriorly dislocated (Figure 4). A hyperechoic hemarthrosis is often seen in the joint when shoulder is anteriorly dislocated.

Facilitation of Reduction

Ultrasound-guided intra-articular joint injection is a simple and effective technique to deliver anesthesia to the shoulder.³ Imaging is performed with the same curvilinear probe using sterile precautions—ie, sterile probe and cord cover, sterile gloves, and skin prepped with chlorhexidine. To access the shoulder joint, a long needle, such as a spinal needle, is utilized to deliver a short-acting local anesthetic (eg, 1% lidocaine). It is essential to line up the probe marker with the screen marker to facilitate needle placement and adjustment. The spinal needle is inserted into the lateral deltoid, beneath the acromion and a few centimeters from the edge of the probe. It is then directed by ultrasound in real-time toward the hemarthrosis. Once the needle is within the joint, fluid should be aspirated to confirm return of blood and inject 20 cc of lidocaine (Figure 5). A video demonstrating this technique may be accessed online at https://vimeo.com/156762428. Before performing the reduction technique of choice, the clinician should wait 10 to 15 minutes for the joint injection to take effect.

Summary

Bedside ultrasound is an excellent adjunct to traditional radiographs in the evaluation of patients presenting with shoulder injuries. In addition to its high sensitivity in detecting dislocation, this modality can be used to guide intra-articular treatment and to confirm successful reduction.

---

Dr Meer is an assistant professor and director of emergency ultrasound, department of emergency medicine, Emory University School of Medicine, Atlanta. Dr Beck is an assistant professor, department of emergency medicine, Emory University School of Medicine, Atlanta. Dr Taylor is an assistant professor and director of postgraduate medical education, department of emergency medicine, Emory University School of Medicine, Atlanta.

Oral prednisolone is as effective as indomethacin for relieving pain in acute gout and should be considered a first-line treatment option, according to a report published online Feb. 22 in Annals of Internal Medicine.

Colchicine and nonsteroidal anti-inflammatory drugs have been considered the first-line treatment for acute gout for many years. “However, their use is limited in elderly adults and in patients with comorbid conditions (such as renal insufficiency or gastrointestinal disease) because of their potential adverse effects and drug interactions,” said Dr. Timothy Hudson Rainer of the emergency medicine academic unit, Cardiff (Wales) University, and his associates.

©ThamKC/Thinkstock

They performed a double-blind, randomized trial comparing oral indomethacin against oral prednisolone in 416 patients who presented during a 2-year period to the emergency departments of four Hong Kong hospitals, where acute gout typically is treated in the ED. Those who were randomized to indomethacin initially received 50 mg (two 25-mg tablets) of the drug three times a day and six tablets of oral placebo prednisolone once a day for 2 days, followed by 25 mg of indomethacin three times a day and six tablets of placebo prednisolone once a day for 3 days. Prednisolone-treated patients initially received 30 mg (three 10-mg tablets) of the drug once a day and two tablets of placebo indomethacin three times a day for 2 days, followed by 30 mg (three 10-mg tablets) of prednisolone once a day and one tablet of placebo indomethacin three times a day for 3 days. All the patients received 1 g oral paracetamol to be taken every 6 hours as needed. The mean patient age was 65 years, and most (74%) of the study participants had a history of recurrent gout. The patients were followed for 2 weeks.

Scores on several measures of joint pain, redness, and tenderness were equivalent between the two treatment groups throughout the study period. During a 2-hour period at the emergency department, 100-mm visual analog scale (VAS) pain scores at rest declined by 6.54 mm/hour with indomethacin and by 5.05 mm/hour with prednisolone, and with activity, the declines were 11.69 mm/hour and 11.38 mm/hour, respectively. VAS scores declined during days 1-14 of treatment by similar mean amounts both at rest (1.80 mm/day for indomethacin and 1.68 mm/day for prednisolone) and with activity (2.96 mm/day vs. 3.19 mm/day, respectively). All VAS pain score improvements except for the one at rest in the ED exceeded 13 mm, meeting the definition for clinically meaningful improvement. The number of patients who showed clinically meaningful declines in pain scores also was equivalent between the two groups in both the intention-to-treat and the per-protocol analyses, the investigators said (Ann Intern Med. 2016 Feb 23. doi: 10.7326/M14-2070).

Both groups also showed similar responses in secondary endpoints of improvement in redness and tenderness of the affected joints, need for additional paracetamol, and patient satisfaction with analgesia.

There were no serious adverse events, but seven patients in the indomethacin group and one in the prednisolone group discontinued treatment because of adverse signs or symptoms. This included abdominal pain, dizziness, and lethargy among patients taking indomethacin and mild hyperkalemia in the patient taking prednisolone. The rate of minor adverse events was significantly higher with indomethacin (19%) than with prednisolone (6%).

“Our study provides robust evidence that oral corticosteroids are as effective at treating pain and as acceptable to patients as NSAIDs,” Dr. Rainer and his associates noted.

This trial was supported by the Hong Kong government’s Health and Health Services Research Grant Committee. Dr. Rainer and his associates reported having no relevant financial disclosures.

Oral prednisolone is as effective as indomethacin for relieving pain in acute gout and should be considered a first-line treatment option, according to a report published online Feb. 22 in Annals of Internal Medicine.

Colchicine and nonsteroidal anti-inflammatory drugs have been considered the first-line treatment for acute gout for many years. “However, their use is limited in elderly adults and in patients with comorbid conditions (such as renal insufficiency or gastrointestinal disease) because of their potential adverse effects and drug interactions,” said Dr. Timothy Hudson Rainer of the emergency medicine academic unit, Cardiff (Wales) University, and his associates.

©ThamKC/Thinkstock

They performed a double-blind, randomized trial comparing oral indomethacin against oral prednisolone in 416 patients who presented during a 2-year period to the emergency departments of four Hong Kong hospitals, where acute gout typically is treated in the ED. Those who were randomized to indomethacin initially received 50 mg (two 25-mg tablets) of the drug three times a day and six tablets of oral placebo prednisolone once a day for 2 days, followed by 25 mg of indomethacin three times a day and six tablets of placebo prednisolone once a day for 3 days. Prednisolone-treated patients initially received 30 mg (three 10-mg tablets) of the drug once a day and two tablets of placebo indomethacin three times a day for 2 days, followed by 30 mg (three 10-mg tablets) of prednisolone once a day and one tablet of placebo indomethacin three times a day for 3 days. All the patients received 1 g oral paracetamol to be taken every 6 hours as needed. The mean patient age was 65 years, and most (74%) of the study participants had a history of recurrent gout. The patients were followed for 2 weeks.

Scores on several measures of joint pain, redness, and tenderness were equivalent between the two treatment groups throughout the study period. During a 2-hour period at the emergency department, 100-mm visual analog scale (VAS) pain scores at rest declined by 6.54 mm/hour with indomethacin and by 5.05 mm/hour with prednisolone, and with activity, the declines were 11.69 mm/hour and 11.38 mm/hour, respectively. VAS scores declined during days 1-14 of treatment by similar mean amounts both at rest (1.80 mm/day for indomethacin and 1.68 mm/day for prednisolone) and with activity (2.96 mm/day vs. 3.19 mm/day, respectively). All VAS pain score improvements except for the one at rest in the ED exceeded 13 mm, meeting the definition for clinically meaningful improvement. The number of patients who showed clinically meaningful declines in pain scores also was equivalent between the two groups in both the intention-to-treat and the per-protocol analyses, the investigators said (Ann Intern Med. 2016 Feb 23. doi: 10.7326/M14-2070).

Both groups also showed similar responses in secondary endpoints of improvement in redness and tenderness of the affected joints, need for additional paracetamol, and patient satisfaction with analgesia.

There were no serious adverse events, but seven patients in the indomethacin group and one in the prednisolone group discontinued treatment because of adverse signs or symptoms. This included abdominal pain, dizziness, and lethargy among patients taking indomethacin and mild hyperkalemia in the patient taking prednisolone. The rate of minor adverse events was significantly higher with indomethacin (19%) than with prednisolone (6%).

“Our study provides robust evidence that oral corticosteroids are as effective at treating pain and as acceptable to patients as NSAIDs,” Dr. Rainer and his associates noted.

This trial was supported by the Hong Kong government’s Health and Health Services Research Grant Committee. Dr. Rainer and his associates reported having no relevant financial disclosures.

Oral prednisolone is as effective as indomethacin for relieving pain in acute gout and should be considered a first-line treatment option, according to a report published online Feb. 22 in Annals of Internal Medicine.

Colchicine and nonsteroidal anti-inflammatory drugs have been considered the first-line treatment for acute gout for many years. “However, their use is limited in elderly adults and in patients with comorbid conditions (such as renal insufficiency or gastrointestinal disease) because of their potential adverse effects and drug interactions,” said Dr. Timothy Hudson Rainer of the emergency medicine academic unit, Cardiff (Wales) University, and his associates.

©ThamKC/Thinkstock

They performed a double-blind, randomized trial comparing oral indomethacin against oral prednisolone in 416 patients who presented during a 2-year period to the emergency departments of four Hong Kong hospitals, where acute gout typically is treated in the ED. Those who were randomized to indomethacin initially received 50 mg (two 25-mg tablets) of the drug three times a day and six tablets of oral placebo prednisolone once a day for 2 days, followed by 25 mg of indomethacin three times a day and six tablets of placebo prednisolone once a day for 3 days. Prednisolone-treated patients initially received 30 mg (three 10-mg tablets) of the drug once a day and two tablets of placebo indomethacin three times a day for 2 days, followed by 30 mg (three 10-mg tablets) of prednisolone once a day and one tablet of placebo indomethacin three times a day for 3 days. All the patients received 1 g oral paracetamol to be taken every 6 hours as needed. The mean patient age was 65 years, and most (74%) of the study participants had a history of recurrent gout. The patients were followed for 2 weeks.

Scores on several measures of joint pain, redness, and tenderness were equivalent between the two treatment groups throughout the study period. During a 2-hour period at the emergency department, 100-mm visual analog scale (VAS) pain scores at rest declined by 6.54 mm/hour with indomethacin and by 5.05 mm/hour with prednisolone, and with activity, the declines were 11.69 mm/hour and 11.38 mm/hour, respectively. VAS scores declined during days 1-14 of treatment by similar mean amounts both at rest (1.80 mm/day for indomethacin and 1.68 mm/day for prednisolone) and with activity (2.96 mm/day vs. 3.19 mm/day, respectively). All VAS pain score improvements except for the one at rest in the ED exceeded 13 mm, meeting the definition for clinically meaningful improvement. The number of patients who showed clinically meaningful declines in pain scores also was equivalent between the two groups in both the intention-to-treat and the per-protocol analyses, the investigators said (Ann Intern Med. 2016 Feb 23. doi: 10.7326/M14-2070).

Both groups also showed similar responses in secondary endpoints of improvement in redness and tenderness of the affected joints, need for additional paracetamol, and patient satisfaction with analgesia.

There were no serious adverse events, but seven patients in the indomethacin group and one in the prednisolone group discontinued treatment because of adverse signs or symptoms. This included abdominal pain, dizziness, and lethargy among patients taking indomethacin and mild hyperkalemia in the patient taking prednisolone. The rate of minor adverse events was significantly higher with indomethacin (19%) than with prednisolone (6%).

“Our study provides robust evidence that oral corticosteroids are as effective at treating pain and as acceptable to patients as NSAIDs,” Dr. Rainer and his associates noted.

This trial was supported by the Hong Kong government’s Health and Health Services Research Grant Committee. Dr. Rainer and his associates reported having no relevant financial disclosures.

Injuries among professional baseball players have been on the rise for several years.^1,2 From 1989 to 1999, the number of disabled list (DL) reports increased 38% (266 to 367 annual reports),¹ and a similar increase in injury rates was noted from the 2002 to the 2008 seasons (37%).² These injuries have important implications for future injury risk and time away from play. Identifying these injuries and determining correlates and risk factors is important for targeted prevention efforts.

Several studies have explored the prevalence of upper extremity injuries in professional and collegiate baseball players;^2-4 however, detailed epidemiology of knee injuries in Major League Baseball (MLB) and Minor League Baseball (MiLB) players is lacking. Much more is known about the prevalence, treatment, and outcomes of knee injuries in other professional sporting organizations, such as the National Basketball Association (NBA), National Football League (NFL), and National Hockey League (NHL).^4-12 A recent meta-analysis exploring injuries in professional athletes found that studies on lower extremity injuries comprised approximately 12% of the literature reporting injuries in MLB players.⁴ In other professional leagues, publications on lower extremity injuries comprise approximately 56% of the sports medicine literature in the NFL, 54% in the NBA, and 62% in the NHL.⁴ Since few studies have investigated lower extremity injuries among professional baseball players, there is an opportunity for additional research to guide evidence-based prevention strategies.

A better understanding of the nature of these injuries is one of the first steps towards developing targeted injury prevention programs and treatment algorithms. The study of injury epidemiology among professional baseball players has been aided by the creation of an injury tracking system initiated by the MLB, its minor league affiliates, and the Major League Baseball Players Association.^5,13,14 This surveillance system allows for the tracking of medical histories and injuries to players as they move across major and minor league organizations. Similar systems have been utilized in the National Collegiate Athletic Association and other professional sports organizations.^3,15-17 A unique advantage of the MLB surveillance system is the required participation of all major and minor league teams, which allows for investigation of the entire population of players rather than simply a sample of players from select teams. This system has propelled an effort to identify injury patterns as a means of developing appropriate targets for potential preventative measures.⁵

The purpose of this descriptive epidemiologic study is to better understand the distribution and characteristics of knee injuries in these elite athletes by reporting on all knee injuries occurring over a span of 4 seasons (2011-2014). Additionally, this study seeks to characterize the impact of these injuries by analyzing the time required for return to play and the treatments rendered (surgical and nonsurgical).

Materials and Methods

After approval from the Johns Hopkins Bloomberg School of Public Health Institutional Review Board, detailed data regarding knee injuries in both MLB and MiLB baseball players were extracted from the de-identified MLB Health and Injury Tracking System (HITS). The HITS database is a centralized database that contains data on injuries from an electronic medical record (EMR). All players provided consent to have their data included in this EMR. HITS system captures injuries reported by the athletic trainers for all professional baseball players from 30 MLB clubs and their 230 minor league affiliates. Additional details on this population of professional baseball players have been published elsewhere.⁵ Only injuries that result in time out of play (≥1 day missed) are included in the database, and they are logged with basic information such as region of the body, diagnosis, date, player position, activity leading to injury, and general treatment. Any injury that affects participation in any aspect of baseball-related activity (eg, game, practice, warm-up, conditioning, weight training) is captured in HITS.

All baseball-related knee injuries occurring during the 2011-2014 seasons that resulted in time out of sport were included in the study. These injuries were identified based on the Sports Medicine Diagnostic Coding System (SMDCS) to capture injuries by diagnostic groups.¹⁸ Knee injuries were included if they occurred during spring training, regular season, or postseason play. Offseason injuries were not included. Injury events that were classified as “season-ending” were not included in the analysis of days missed because many of these players may not have been cleared to play until the beginning of the following season. To determine the proportion of knee injuries during the study period, all injuries were included for comparative purposes (subdivided based on 30 anatomic regions or types).

For each knee injury, a number of variables were analyzed, including diagnosis, level of play (MLB vs. MiLB), age, player position at the time of injury (pitcher, catcher, infield, outfield, base runner, or batter), field location where the injury occurred (home plate, pitcher’s mound, infield, outfield, foul territory or bullpen, or other), mechanism of injury, days missed, and treatment rendered (conservative vs surgical). The classification used to describe the mechanism of injury consisted of contact with ball, contact with ground, contact with another player, contact with another object, or noncontact.

 

Statistical Analysis
Epidemiologic data are presented with descriptive statistics such as mean, median, frequency, and percentage where appropriate. When comparing player age, days missed, and surgical vs nonsurgical treatment between MLB and MiLB players, t-tests and tests for difference in proportions were applied as appropriate. Statistical significance was established for P values < .05.

The distribution of days missed for the variables considered was often skewed to the right (ie, days missed mostly concentrated on the low to moderate number of days, with fewer values in the much higher days missed range), even after excluding the season-ending injuries; hence the mean (or average) days missed was often larger than the median days missed. Reporting the median would allow for a robust estimate of the expected number of days missed, but would down weight those instances when knee injuries result in much longer missed days, as reflected by the mean. Because of the importance of the days missed measure for professional baseball, both the mean and median are presented.

In order to estimate exposure, the average number of players per team per game was calculated based on analysis of regular season game participation via box scores. This average number over a season, multiplied by the number of team games at each professional level of baseball, was used as an estimate of athlete exposures in order to provide rates comparable to those of other injury surveillance systems. Injury rates were reported as injuries per 1000 athlete-exposures (AE) for those knee injuries that occurred during the regular season. It should be noted that the number of regular season knee injuries and the subsequent AE rates are based on injuries that were deemed work-related during the regular season. This does not necessarily only include injuries occurring during the course of a game, but injuries in game preparation as well. Due to the variations in spring training games and fluctuating rosters, an exposure rate could not be calculated for spring training knee injuries.

RESULTS

Overall Summary

Of the 30 general body regions/systems included in the HITS database, injuries to the knee were the fifth most common reason for days missed in all of professional baseball from 2011-2014 (Table 1). Injuries to the knee represented 6.5% of the nearly 34,000 injuries sustained during the study period. Knee injuries were the fifth most common reason for time out of play for players in both the MiLB and MLB.

A total of 2171 isolated knee injuries resulted in time out of sport for professional baseball players (Table 2). Of these, 410 (19%) occurred in MLB players and 1761 (81%) occurred in MiLB players. MLB players were older than MiLB players at the time of injury (29.5 vs 22.8 years, respectively). Overall mean number of days missed was 16.2 days per knee injury, with MLB players missing an approximately 7 days more per injury than MiLB athletes (21.8 vs. 14.9 days respectively; P = .001).Over the course of the 4 seasons, a total of 30,449 days were missed due to knee injuries in professional baseball, giving an average rate of 7612 days lost per season. Surgery was performed for 263 (12.1%) of the 2171 knee injuries, with a greater proportion of MLB players requiring surgery than MiLB players (17.3% vs 10.9%) (P < .001). With respect to number of days missed per injury, 26% of knee injuries in the minor leagues resulted in greater than 30 days missed, while this number rose to 32% for knee injuries in MLB players (Table 3).

For regular season games, it was estimated that there were 1,197,738 MiLB and 276,608 MLB AE, respectively, over the course of the 4 seasons (2011-2014). The overall knee injury rate across both the MiLB and MLB was 1.2 per 1000 AE, based on the subset of 308 and 1473 regular season knee injuries in MiLB and MLB, respectively. The rate of knee injury was similar and not significantly different between the MiLB and MLB (1.2 per 1000 AE in the MiLB and 1.1 per 1000 AE in the MLB).

Characteristics of Injuries

When considering the position of the player during injury, defensive players were most frequently injured (n = 742, 56.5%), with pitchers (n = 227, 17.3%), infielders (n =193, 14.7%), outfielders (n = 193, 14.7%), and catchers (n = 129, 9.8%) sustaining injuries in decreasing frequency. Injuries while on offense (n = 571, 43.5%) were most frequent in base runners (n = 320, 24.4%) followed by batters (n = 251, 19.1%) (Table 4). Injuries while on defense occurring in infielders and catchers resulted in the longest period of time away from play (average of 22.4 and 20.8 days missed, respectively), while those occurring in batters resulted in the least average days missed (8.9 days).

 

The most common field location for knee injuries to occur was the infield, which was responsible for n = 647 (29.8%) of the total knee injuries (Table 4). This was followed by home plate (n = 493, 22.7%), other locations outside those specified (n = 394, 18.1%), outfield (n = 320, 14.7%), pitcher’s mound (n = 210, 9.7%), and foul territory or the bullpen (n = 107, 4.9%). Of the knee injuries with a specified location, those occurring in foul territory or the bullpen resulted in the highest mean days missed (18.4), while those occurring at home plate resulted in the least mean days missed (13.4 days).

When analyzed by mechanism of injury, noncontact injuries (n = 953, 43.9%) were more common than being hit with the ball (n = 374, 17.2%), striking the ground (n = 409, 18.8%), other mechanisms not listed (n = 196, 9%), contact with another player (n = 176, 8.1%), or contact with other objects (n = 63, 2.9%) (Table 4). Noncontact injuries and player to player collisions resulted in the greatest number of missed days (21.6 and 17.1 days, respectively) while being struck by the ball resulted in the least mean days missed (5.1).

Of the n = 493 knee injuries occurring at home plate, n = 212 (43%) occurred to the batter, n = 100 (20%) to the catcher, n = 34 (6.9%) to base runners, and n = 7 (1.4%) to pitchers (Table 5). The majority of knee injuries in the infield occurred to base runners (n = 283, 43.7%). Player-to-player collisions at home plate were responsible for 51 (2.3%) knee injuries, while 163 (24%) were noncontact injuries and 376 (56%) were the result of a player being hit by the ball (Table 5).

Injury Diagnosis

By diagnosis, the most common knee injuries observed were contusions or hematomas (n = 662, 30.5%), other injuries (n = 415, 19.1%), sprains or ligament injuries (n = 380, 17.5%), tendinopathies or bursitis (n = 367, 16.9%), and meniscal or cartilage injury (n = 200, 9.2%) (Table 6). Injuries resulting in the greatest mean number of days missed included meniscal or cartilage injuries (44 days), sprains or ligament injuries (30 days), or dislocations (22 days).

Based on specific SMDCS descriptors, the most frequent knee injuries reported were contusion (n = 662, 30.5%), patella tendinopathy (n = 222, 10.2%), and meniscal tears (n = 200, 9.2%) (Table 6). Complete anterior cruciate ligament tears, although infrequent, were responsible for the greatest mean days missed (156.2 days). This was followed by lateral meniscus tears (47.5 days) and medial meniscus tears (41.2 days). Knee contusions, although very common, resulted in the least number of days missed (6.0 days).

Discussion

Although much is known about knee injuries in other professional athletic leagues, little is known about knee injuries in professional baseball players.^2-4 The majority of epidemiologic studies regarding baseball players at any level emphasizes the study of shoulder and elbow injuries.^3,4,19 Since the implementation of the electronic medical record and the HITS database in professional baseball, there has been increased effort to document injuries that have received less attention in the existing literature. Understanding the epidemiology of these injuries is important for the development of targeted prevention efforts.

Prior studies of injuries in professional baseball relied on data captured by the publicly available DL. Posner and colleagues² provide one of the most comprehensive reports on MLB injuries in a report utilizing DL assignment data over a period of 7 seasons.They demonstrated that knee injuries were responsible for 7.7% (12.5% for fielders and 3.7% for pitchers) of assignments to the DL. The current study utilized a comprehensive surveillance and builds on this existing knowledge. The present study found similar trends to Posner and colleagues² in that knee injuries were responsible for 6.5% of injuries in professional baseball players that resulted in missed games. From the 2002 season to the 2008 season, knee injuries were the fifth most common reason MLB players were placed on the DL,² and the current study indicates that they remain the fifth most common reason for missed time from play based on the HITS data. Since the prevalence of these injuries have remained constant since the 2002 season, efforts to better understand these injuries are warranted in order to identify strategies to prevent them. These analyses have generated important data towards achieving this understanding.

As with most injuries in professional sports, goals for treatment are aimed at maximizing patient function and performance while minimizing time out of play. For the 2011-2014 professional baseball seasons, a total of 2171 players sustained knee injuries and missed an average of 16.2 days per injury. Knee injuries were responsible for a total of 7612 days of missed work for MLB and MiLB players per season (30,449 days over the 4-season study period). This is equivalent to a total of 20.9 years of players’ time lost in professional baseball per season over the last 4 years. The implications of this amount of time away from sport are significant, and further study should be targeted at prevention of these injuries and optimizing return to play times.

 

When attempting to reduce the burden of knee injuries in professional baseball, it may prove beneficial to first understand how the injuries occur, where on the field, and who is at greatest risk. From 2011 to 2014, nearly 44% of knee injuries occurred by noncontact mechanisms. Among all locations on the field where knee injuries occurred, those occurring in the infield were responsible for the greatest mean days missed. The players who seem to be at greatest risk for knee injuries appear to be base runners. These data suggest the need for prevention efforts targeting base runners and infield players, as well as players in MiLB, where the largest number of injuries occurred.

Recently, playing rules implemented by MLB after consultation with players have focused on reducing the number of player-to-player collisions at home plate in an attempt to decrease the injury burden to catchers and base runners.²⁰ This present analysis suggests that this rule change may also reduce the occurrence of knee injuries, as player collisions at home plate were responsible for a total of 51 knee injuries during the study period. The impact of this rule change on injury rates should also be explored. Interestingly, of the 51 knees injuries occurring due to contact at home plate, 23 occurred in 2011, and only 2 occurred in 2014—the first year of the new rule. Additional areas that resulted in high numbers of knee injuries were player-to-player contact in the infield and player contact with the ground in the infield.

Attempting to reduce injury burden and time out of play related to knee injuries in professional baseball players will likely prove to be a difficult task. In order to generate meaningful improvement, a comprehensive approach that involves players, management, trainers, therapists, and physicians will likely be required. As the first report of the epidemiology of knee injuries in professional baseball players, this study is one important step in that process. The strengths of this study are its comprehensive nature that analyzes injuries from an entire population of players on more than 200 teams over a 3-year period. Also, this research is strengthened by its focus on one particular region of the body that has received limited attention in the empirical literature, but represents a significant source of lost time during the baseball season.

There are some limitations to this study. As with any injury surveillance system, there is the possibility that not all cases were captured. Additionally, since the surveillance system is based on data from multiple teams, data entry discrepancy is possible; however, the presence of dropdown boxes and systematic definitions for injuries reduces this risk. Finally, this study did not investigate the various treatments for knee injuries beyond whether or not the injury required surgery. Since this was the first comprehensive exploration of knee injuries in professional baseball, future studies are needed to explore additional facets including outcomes related to treatment, return to play, and performance.

Conclusion

Knee injuries represent 6.5% of all injuries in professional baseball, occurring at a rate of 1.3 per 1000 AE. The burden of these injuries is significant for professional baseball players. This study fills a critical gap in sports injury research by contributing to the knowledge about the effect of knee injuries in professional baseball. It also provides an important foundation for future epidemiologic inquiry to identify modifiable risk factors and interventions that may reduce the impact of these injuries in athletes.

Injuries among professional baseball players have been on the rise for several years.^1,2 From 1989 to 1999, the number of disabled list (DL) reports increased 38% (266 to 367 annual reports),¹ and a similar increase in injury rates was noted from the 2002 to the 2008 seasons (37%).² These injuries have important implications for future injury risk and time away from play. Identifying these injuries and determining correlates and risk factors is important for targeted prevention efforts.

Several studies have explored the prevalence of upper extremity injuries in professional and collegiate baseball players;^2-4 however, detailed epidemiology of knee injuries in Major League Baseball (MLB) and Minor League Baseball (MiLB) players is lacking. Much more is known about the prevalence, treatment, and outcomes of knee injuries in other professional sporting organizations, such as the National Basketball Association (NBA), National Football League (NFL), and National Hockey League (NHL).^4-12 A recent meta-analysis exploring injuries in professional athletes found that studies on lower extremity injuries comprised approximately 12% of the literature reporting injuries in MLB players.⁴ In other professional leagues, publications on lower extremity injuries comprise approximately 56% of the sports medicine literature in the NFL, 54% in the NBA, and 62% in the NHL.⁴ Since few studies have investigated lower extremity injuries among professional baseball players, there is an opportunity for additional research to guide evidence-based prevention strategies.

A better understanding of the nature of these injuries is one of the first steps towards developing targeted injury prevention programs and treatment algorithms. The study of injury epidemiology among professional baseball players has been aided by the creation of an injury tracking system initiated by the MLB, its minor league affiliates, and the Major League Baseball Players Association.^5,13,14 This surveillance system allows for the tracking of medical histories and injuries to players as they move across major and minor league organizations. Similar systems have been utilized in the National Collegiate Athletic Association and other professional sports organizations.^3,15-17 A unique advantage of the MLB surveillance system is the required participation of all major and minor league teams, which allows for investigation of the entire population of players rather than simply a sample of players from select teams. This system has propelled an effort to identify injury patterns as a means of developing appropriate targets for potential preventative measures.⁵

The purpose of this descriptive epidemiologic study is to better understand the distribution and characteristics of knee injuries in these elite athletes by reporting on all knee injuries occurring over a span of 4 seasons (2011-2014). Additionally, this study seeks to characterize the impact of these injuries by analyzing the time required for return to play and the treatments rendered (surgical and nonsurgical).

Materials and Methods

After approval from the Johns Hopkins Bloomberg School of Public Health Institutional Review Board, detailed data regarding knee injuries in both MLB and MiLB baseball players were extracted from the de-identified MLB Health and Injury Tracking System (HITS). The HITS database is a centralized database that contains data on injuries from an electronic medical record (EMR). All players provided consent to have their data included in this EMR. HITS system captures injuries reported by the athletic trainers for all professional baseball players from 30 MLB clubs and their 230 minor league affiliates. Additional details on this population of professional baseball players have been published elsewhere.⁵ Only injuries that result in time out of play (≥1 day missed) are included in the database, and they are logged with basic information such as region of the body, diagnosis, date, player position, activity leading to injury, and general treatment. Any injury that affects participation in any aspect of baseball-related activity (eg, game, practice, warm-up, conditioning, weight training) is captured in HITS.

All baseball-related knee injuries occurring during the 2011-2014 seasons that resulted in time out of sport were included in the study. These injuries were identified based on the Sports Medicine Diagnostic Coding System (SMDCS) to capture injuries by diagnostic groups.¹⁸ Knee injuries were included if they occurred during spring training, regular season, or postseason play. Offseason injuries were not included. Injury events that were classified as “season-ending” were not included in the analysis of days missed because many of these players may not have been cleared to play until the beginning of the following season. To determine the proportion of knee injuries during the study period, all injuries were included for comparative purposes (subdivided based on 30 anatomic regions or types).

For each knee injury, a number of variables were analyzed, including diagnosis, level of play (MLB vs. MiLB), age, player position at the time of injury (pitcher, catcher, infield, outfield, base runner, or batter), field location where the injury occurred (home plate, pitcher’s mound, infield, outfield, foul territory or bullpen, or other), mechanism of injury, days missed, and treatment rendered (conservative vs surgical). The classification used to describe the mechanism of injury consisted of contact with ball, contact with ground, contact with another player, contact with another object, or noncontact.

 

Statistical Analysis
Epidemiologic data are presented with descriptive statistics such as mean, median, frequency, and percentage where appropriate. When comparing player age, days missed, and surgical vs nonsurgical treatment between MLB and MiLB players, t-tests and tests for difference in proportions were applied as appropriate. Statistical significance was established for P values < .05.

The distribution of days missed for the variables considered was often skewed to the right (ie, days missed mostly concentrated on the low to moderate number of days, with fewer values in the much higher days missed range), even after excluding the season-ending injuries; hence the mean (or average) days missed was often larger than the median days missed. Reporting the median would allow for a robust estimate of the expected number of days missed, but would down weight those instances when knee injuries result in much longer missed days, as reflected by the mean. Because of the importance of the days missed measure for professional baseball, both the mean and median are presented.

In order to estimate exposure, the average number of players per team per game was calculated based on analysis of regular season game participation via box scores. This average number over a season, multiplied by the number of team games at each professional level of baseball, was used as an estimate of athlete exposures in order to provide rates comparable to those of other injury surveillance systems. Injury rates were reported as injuries per 1000 athlete-exposures (AE) for those knee injuries that occurred during the regular season. It should be noted that the number of regular season knee injuries and the subsequent AE rates are based on injuries that were deemed work-related during the regular season. This does not necessarily only include injuries occurring during the course of a game, but injuries in game preparation as well. Due to the variations in spring training games and fluctuating rosters, an exposure rate could not be calculated for spring training knee injuries.

RESULTS

Overall Summary

Of the 30 general body regions/systems included in the HITS database, injuries to the knee were the fifth most common reason for days missed in all of professional baseball from 2011-2014 (Table 1). Injuries to the knee represented 6.5% of the nearly 34,000 injuries sustained during the study period. Knee injuries were the fifth most common reason for time out of play for players in both the MiLB and MLB.

A total of 2171 isolated knee injuries resulted in time out of sport for professional baseball players (Table 2). Of these, 410 (19%) occurred in MLB players and 1761 (81%) occurred in MiLB players. MLB players were older than MiLB players at the time of injury (29.5 vs 22.8 years, respectively). Overall mean number of days missed was 16.2 days per knee injury, with MLB players missing an approximately 7 days more per injury than MiLB athletes (21.8 vs. 14.9 days respectively; P = .001).Over the course of the 4 seasons, a total of 30,449 days were missed due to knee injuries in professional baseball, giving an average rate of 7612 days lost per season. Surgery was performed for 263 (12.1%) of the 2171 knee injuries, with a greater proportion of MLB players requiring surgery than MiLB players (17.3% vs 10.9%) (P < .001). With respect to number of days missed per injury, 26% of knee injuries in the minor leagues resulted in greater than 30 days missed, while this number rose to 32% for knee injuries in MLB players (Table 3).

For regular season games, it was estimated that there were 1,197,738 MiLB and 276,608 MLB AE, respectively, over the course of the 4 seasons (2011-2014). The overall knee injury rate across both the MiLB and MLB was 1.2 per 1000 AE, based on the subset of 308 and 1473 regular season knee injuries in MiLB and MLB, respectively. The rate of knee injury was similar and not significantly different between the MiLB and MLB (1.2 per 1000 AE in the MiLB and 1.1 per 1000 AE in the MLB).

Characteristics of Injuries

When considering the position of the player during injury, defensive players were most frequently injured (n = 742, 56.5%), with pitchers (n = 227, 17.3%), infielders (n =193, 14.7%), outfielders (n = 193, 14.7%), and catchers (n = 129, 9.8%) sustaining injuries in decreasing frequency. Injuries while on offense (n = 571, 43.5%) were most frequent in base runners (n = 320, 24.4%) followed by batters (n = 251, 19.1%) (Table 4). Injuries while on defense occurring in infielders and catchers resulted in the longest period of time away from play (average of 22.4 and 20.8 days missed, respectively), while those occurring in batters resulted in the least average days missed (8.9 days).

 

The most common field location for knee injuries to occur was the infield, which was responsible for n = 647 (29.8%) of the total knee injuries (Table 4). This was followed by home plate (n = 493, 22.7%), other locations outside those specified (n = 394, 18.1%), outfield (n = 320, 14.7%), pitcher’s mound (n = 210, 9.7%), and foul territory or the bullpen (n = 107, 4.9%). Of the knee injuries with a specified location, those occurring in foul territory or the bullpen resulted in the highest mean days missed (18.4), while those occurring at home plate resulted in the least mean days missed (13.4 days).

When analyzed by mechanism of injury, noncontact injuries (n = 953, 43.9%) were more common than being hit with the ball (n = 374, 17.2%), striking the ground (n = 409, 18.8%), other mechanisms not listed (n = 196, 9%), contact with another player (n = 176, 8.1%), or contact with other objects (n = 63, 2.9%) (Table 4). Noncontact injuries and player to player collisions resulted in the greatest number of missed days (21.6 and 17.1 days, respectively) while being struck by the ball resulted in the least mean days missed (5.1).

Of the n = 493 knee injuries occurring at home plate, n = 212 (43%) occurred to the batter, n = 100 (20%) to the catcher, n = 34 (6.9%) to base runners, and n = 7 (1.4%) to pitchers (Table 5). The majority of knee injuries in the infield occurred to base runners (n = 283, 43.7%). Player-to-player collisions at home plate were responsible for 51 (2.3%) knee injuries, while 163 (24%) were noncontact injuries and 376 (56%) were the result of a player being hit by the ball (Table 5).

Injury Diagnosis

By diagnosis, the most common knee injuries observed were contusions or hematomas (n = 662, 30.5%), other injuries (n = 415, 19.1%), sprains or ligament injuries (n = 380, 17.5%), tendinopathies or bursitis (n = 367, 16.9%), and meniscal or cartilage injury (n = 200, 9.2%) (Table 6). Injuries resulting in the greatest mean number of days missed included meniscal or cartilage injuries (44 days), sprains or ligament injuries (30 days), or dislocations (22 days).

Based on specific SMDCS descriptors, the most frequent knee injuries reported were contusion (n = 662, 30.5%), patella tendinopathy (n = 222, 10.2%), and meniscal tears (n = 200, 9.2%) (Table 6). Complete anterior cruciate ligament tears, although infrequent, were responsible for the greatest mean days missed (156.2 days). This was followed by lateral meniscus tears (47.5 days) and medial meniscus tears (41.2 days). Knee contusions, although very common, resulted in the least number of days missed (6.0 days).

Discussion

Although much is known about knee injuries in other professional athletic leagues, little is known about knee injuries in professional baseball players.^2-4 The majority of epidemiologic studies regarding baseball players at any level emphasizes the study of shoulder and elbow injuries.^3,4,19 Since the implementation of the electronic medical record and the HITS database in professional baseball, there has been increased effort to document injuries that have received less attention in the existing literature. Understanding the epidemiology of these injuries is important for the development of targeted prevention efforts.

Prior studies of injuries in professional baseball relied on data captured by the publicly available DL. Posner and colleagues² provide one of the most comprehensive reports on MLB injuries in a report utilizing DL assignment data over a period of 7 seasons.They demonstrated that knee injuries were responsible for 7.7% (12.5% for fielders and 3.7% for pitchers) of assignments to the DL. The current study utilized a comprehensive surveillance and builds on this existing knowledge. The present study found similar trends to Posner and colleagues² in that knee injuries were responsible for 6.5% of injuries in professional baseball players that resulted in missed games. From the 2002 season to the 2008 season, knee injuries were the fifth most common reason MLB players were placed on the DL,² and the current study indicates that they remain the fifth most common reason for missed time from play based on the HITS data. Since the prevalence of these injuries have remained constant since the 2002 season, efforts to better understand these injuries are warranted in order to identify strategies to prevent them. These analyses have generated important data towards achieving this understanding.

As with most injuries in professional sports, goals for treatment are aimed at maximizing patient function and performance while minimizing time out of play. For the 2011-2014 professional baseball seasons, a total of 2171 players sustained knee injuries and missed an average of 16.2 days per injury. Knee injuries were responsible for a total of 7612 days of missed work for MLB and MiLB players per season (30,449 days over the 4-season study period). This is equivalent to a total of 20.9 years of players’ time lost in professional baseball per season over the last 4 years. The implications of this amount of time away from sport are significant, and further study should be targeted at prevention of these injuries and optimizing return to play times.

 

When attempting to reduce the burden of knee injuries in professional baseball, it may prove beneficial to first understand how the injuries occur, where on the field, and who is at greatest risk. From 2011 to 2014, nearly 44% of knee injuries occurred by noncontact mechanisms. Among all locations on the field where knee injuries occurred, those occurring in the infield were responsible for the greatest mean days missed. The players who seem to be at greatest risk for knee injuries appear to be base runners. These data suggest the need for prevention efforts targeting base runners and infield players, as well as players in MiLB, where the largest number of injuries occurred.

Recently, playing rules implemented by MLB after consultation with players have focused on reducing the number of player-to-player collisions at home plate in an attempt to decrease the injury burden to catchers and base runners.²⁰ This present analysis suggests that this rule change may also reduce the occurrence of knee injuries, as player collisions at home plate were responsible for a total of 51 knee injuries during the study period. The impact of this rule change on injury rates should also be explored. Interestingly, of the 51 knees injuries occurring due to contact at home plate, 23 occurred in 2011, and only 2 occurred in 2014—the first year of the new rule. Additional areas that resulted in high numbers of knee injuries were player-to-player contact in the infield and player contact with the ground in the infield.

Attempting to reduce injury burden and time out of play related to knee injuries in professional baseball players will likely prove to be a difficult task. In order to generate meaningful improvement, a comprehensive approach that involves players, management, trainers, therapists, and physicians will likely be required. As the first report of the epidemiology of knee injuries in professional baseball players, this study is one important step in that process. The strengths of this study are its comprehensive nature that analyzes injuries from an entire population of players on more than 200 teams over a 3-year period. Also, this research is strengthened by its focus on one particular region of the body that has received limited attention in the empirical literature, but represents a significant source of lost time during the baseball season.

There are some limitations to this study. As with any injury surveillance system, there is the possibility that not all cases were captured. Additionally, since the surveillance system is based on data from multiple teams, data entry discrepancy is possible; however, the presence of dropdown boxes and systematic definitions for injuries reduces this risk. Finally, this study did not investigate the various treatments for knee injuries beyond whether or not the injury required surgery. Since this was the first comprehensive exploration of knee injuries in professional baseball, future studies are needed to explore additional facets including outcomes related to treatment, return to play, and performance.

Conclusion

Knee injuries represent 6.5% of all injuries in professional baseball, occurring at a rate of 1.3 per 1000 AE. The burden of these injuries is significant for professional baseball players. This study fills a critical gap in sports injury research by contributing to the knowledge about the effect of knee injuries in professional baseball. It also provides an important foundation for future epidemiologic inquiry to identify modifiable risk factors and interventions that may reduce the impact of these injuries in athletes.

Injuries among professional baseball players have been on the rise for several years.^1,2 From 1989 to 1999, the number of disabled list (DL) reports increased 38% (266 to 367 annual reports),¹ and a similar increase in injury rates was noted from the 2002 to the 2008 seasons (37%).² These injuries have important implications for future injury risk and time away from play. Identifying these injuries and determining correlates and risk factors is important for targeted prevention efforts.

Several studies have explored the prevalence of upper extremity injuries in professional and collegiate baseball players;^2-4 however, detailed epidemiology of knee injuries in Major League Baseball (MLB) and Minor League Baseball (MiLB) players is lacking. Much more is known about the prevalence, treatment, and outcomes of knee injuries in other professional sporting organizations, such as the National Basketball Association (NBA), National Football League (NFL), and National Hockey League (NHL).^4-12 A recent meta-analysis exploring injuries in professional athletes found that studies on lower extremity injuries comprised approximately 12% of the literature reporting injuries in MLB players.⁴ In other professional leagues, publications on lower extremity injuries comprise approximately 56% of the sports medicine literature in the NFL, 54% in the NBA, and 62% in the NHL.⁴ Since few studies have investigated lower extremity injuries among professional baseball players, there is an opportunity for additional research to guide evidence-based prevention strategies.

A better understanding of the nature of these injuries is one of the first steps towards developing targeted injury prevention programs and treatment algorithms. The study of injury epidemiology among professional baseball players has been aided by the creation of an injury tracking system initiated by the MLB, its minor league affiliates, and the Major League Baseball Players Association.^5,13,14 This surveillance system allows for the tracking of medical histories and injuries to players as they move across major and minor league organizations. Similar systems have been utilized in the National Collegiate Athletic Association and other professional sports organizations.^3,15-17 A unique advantage of the MLB surveillance system is the required participation of all major and minor league teams, which allows for investigation of the entire population of players rather than simply a sample of players from select teams. This system has propelled an effort to identify injury patterns as a means of developing appropriate targets for potential preventative measures.⁵

The purpose of this descriptive epidemiologic study is to better understand the distribution and characteristics of knee injuries in these elite athletes by reporting on all knee injuries occurring over a span of 4 seasons (2011-2014). Additionally, this study seeks to characterize the impact of these injuries by analyzing the time required for return to play and the treatments rendered (surgical and nonsurgical).

Materials and Methods

After approval from the Johns Hopkins Bloomberg School of Public Health Institutional Review Board, detailed data regarding knee injuries in both MLB and MiLB baseball players were extracted from the de-identified MLB Health and Injury Tracking System (HITS). The HITS database is a centralized database that contains data on injuries from an electronic medical record (EMR). All players provided consent to have their data included in this EMR. HITS system captures injuries reported by the athletic trainers for all professional baseball players from 30 MLB clubs and their 230 minor league affiliates. Additional details on this population of professional baseball players have been published elsewhere.⁵ Only injuries that result in time out of play (≥1 day missed) are included in the database, and they are logged with basic information such as region of the body, diagnosis, date, player position, activity leading to injury, and general treatment. Any injury that affects participation in any aspect of baseball-related activity (eg, game, practice, warm-up, conditioning, weight training) is captured in HITS.

All baseball-related knee injuries occurring during the 2011-2014 seasons that resulted in time out of sport were included in the study. These injuries were identified based on the Sports Medicine Diagnostic Coding System (SMDCS) to capture injuries by diagnostic groups.¹⁸ Knee injuries were included if they occurred during spring training, regular season, or postseason play. Offseason injuries were not included. Injury events that were classified as “season-ending” were not included in the analysis of days missed because many of these players may not have been cleared to play until the beginning of the following season. To determine the proportion of knee injuries during the study period, all injuries were included for comparative purposes (subdivided based on 30 anatomic regions or types).

For each knee injury, a number of variables were analyzed, including diagnosis, level of play (MLB vs. MiLB), age, player position at the time of injury (pitcher, catcher, infield, outfield, base runner, or batter), field location where the injury occurred (home plate, pitcher’s mound, infield, outfield, foul territory or bullpen, or other), mechanism of injury, days missed, and treatment rendered (conservative vs surgical). The classification used to describe the mechanism of injury consisted of contact with ball, contact with ground, contact with another player, contact with another object, or noncontact.

 

Statistical Analysis
Epidemiologic data are presented with descriptive statistics such as mean, median, frequency, and percentage where appropriate. When comparing player age, days missed, and surgical vs nonsurgical treatment between MLB and MiLB players, t-tests and tests for difference in proportions were applied as appropriate. Statistical significance was established for P values < .05.

The distribution of days missed for the variables considered was often skewed to the right (ie, days missed mostly concentrated on the low to moderate number of days, with fewer values in the much higher days missed range), even after excluding the season-ending injuries; hence the mean (or average) days missed was often larger than the median days missed. Reporting the median would allow for a robust estimate of the expected number of days missed, but would down weight those instances when knee injuries result in much longer missed days, as reflected by the mean. Because of the importance of the days missed measure for professional baseball, both the mean and median are presented.

In order to estimate exposure, the average number of players per team per game was calculated based on analysis of regular season game participation via box scores. This average number over a season, multiplied by the number of team games at each professional level of baseball, was used as an estimate of athlete exposures in order to provide rates comparable to those of other injury surveillance systems. Injury rates were reported as injuries per 1000 athlete-exposures (AE) for those knee injuries that occurred during the regular season. It should be noted that the number of regular season knee injuries and the subsequent AE rates are based on injuries that were deemed work-related during the regular season. This does not necessarily only include injuries occurring during the course of a game, but injuries in game preparation as well. Due to the variations in spring training games and fluctuating rosters, an exposure rate could not be calculated for spring training knee injuries.

RESULTS

Overall Summary

Of the 30 general body regions/systems included in the HITS database, injuries to the knee were the fifth most common reason for days missed in all of professional baseball from 2011-2014 (Table 1). Injuries to the knee represented 6.5% of the nearly 34,000 injuries sustained during the study period. Knee injuries were the fifth most common reason for time out of play for players in both the MiLB and MLB.

A total of 2171 isolated knee injuries resulted in time out of sport for professional baseball players (Table 2). Of these, 410 (19%) occurred in MLB players and 1761 (81%) occurred in MiLB players. MLB players were older than MiLB players at the time of injury (29.5 vs 22.8 years, respectively). Overall mean number of days missed was 16.2 days per knee injury, with MLB players missing an approximately 7 days more per injury than MiLB athletes (21.8 vs. 14.9 days respectively; P = .001).Over the course of the 4 seasons, a total of 30,449 days were missed due to knee injuries in professional baseball, giving an average rate of 7612 days lost per season. Surgery was performed for 263 (12.1%) of the 2171 knee injuries, with a greater proportion of MLB players requiring surgery than MiLB players (17.3% vs 10.9%) (P < .001). With respect to number of days missed per injury, 26% of knee injuries in the minor leagues resulted in greater than 30 days missed, while this number rose to 32% for knee injuries in MLB players (Table 3).

For regular season games, it was estimated that there were 1,197,738 MiLB and 276,608 MLB AE, respectively, over the course of the 4 seasons (2011-2014). The overall knee injury rate across both the MiLB and MLB was 1.2 per 1000 AE, based on the subset of 308 and 1473 regular season knee injuries in MiLB and MLB, respectively. The rate of knee injury was similar and not significantly different between the MiLB and MLB (1.2 per 1000 AE in the MiLB and 1.1 per 1000 AE in the MLB).

Characteristics of Injuries

When considering the position of the player during injury, defensive players were most frequently injured (n = 742, 56.5%), with pitchers (n = 227, 17.3%), infielders (n =193, 14.7%), outfielders (n = 193, 14.7%), and catchers (n = 129, 9.8%) sustaining injuries in decreasing frequency. Injuries while on offense (n = 571, 43.5%) were most frequent in base runners (n = 320, 24.4%) followed by batters (n = 251, 19.1%) (Table 4). Injuries while on defense occurring in infielders and catchers resulted in the longest period of time away from play (average of 22.4 and 20.8 days missed, respectively), while those occurring in batters resulted in the least average days missed (8.9 days).

 

The most common field location for knee injuries to occur was the infield, which was responsible for n = 647 (29.8%) of the total knee injuries (Table 4). This was followed by home plate (n = 493, 22.7%), other locations outside those specified (n = 394, 18.1%), outfield (n = 320, 14.7%), pitcher’s mound (n = 210, 9.7%), and foul territory or the bullpen (n = 107, 4.9%). Of the knee injuries with a specified location, those occurring in foul territory or the bullpen resulted in the highest mean days missed (18.4), while those occurring at home plate resulted in the least mean days missed (13.4 days).

When analyzed by mechanism of injury, noncontact injuries (n = 953, 43.9%) were more common than being hit with the ball (n = 374, 17.2%), striking the ground (n = 409, 18.8%), other mechanisms not listed (n = 196, 9%), contact with another player (n = 176, 8.1%), or contact with other objects (n = 63, 2.9%) (Table 4). Noncontact injuries and player to player collisions resulted in the greatest number of missed days (21.6 and 17.1 days, respectively) while being struck by the ball resulted in the least mean days missed (5.1).

Of the n = 493 knee injuries occurring at home plate, n = 212 (43%) occurred to the batter, n = 100 (20%) to the catcher, n = 34 (6.9%) to base runners, and n = 7 (1.4%) to pitchers (Table 5). The majority of knee injuries in the infield occurred to base runners (n = 283, 43.7%). Player-to-player collisions at home plate were responsible for 51 (2.3%) knee injuries, while 163 (24%) were noncontact injuries and 376 (56%) were the result of a player being hit by the ball (Table 5).

Injury Diagnosis

By diagnosis, the most common knee injuries observed were contusions or hematomas (n = 662, 30.5%), other injuries (n = 415, 19.1%), sprains or ligament injuries (n = 380, 17.5%), tendinopathies or bursitis (n = 367, 16.9%), and meniscal or cartilage injury (n = 200, 9.2%) (Table 6). Injuries resulting in the greatest mean number of days missed included meniscal or cartilage injuries (44 days), sprains or ligament injuries (30 days), or dislocations (22 days).

Based on specific SMDCS descriptors, the most frequent knee injuries reported were contusion (n = 662, 30.5%), patella tendinopathy (n = 222, 10.2%), and meniscal tears (n = 200, 9.2%) (Table 6). Complete anterior cruciate ligament tears, although infrequent, were responsible for the greatest mean days missed (156.2 days). This was followed by lateral meniscus tears (47.5 days) and medial meniscus tears (41.2 days). Knee contusions, although very common, resulted in the least number of days missed (6.0 days).

Discussion

Although much is known about knee injuries in other professional athletic leagues, little is known about knee injuries in professional baseball players.^2-4 The majority of epidemiologic studies regarding baseball players at any level emphasizes the study of shoulder and elbow injuries.^3,4,19 Since the implementation of the electronic medical record and the HITS database in professional baseball, there has been increased effort to document injuries that have received less attention in the existing literature. Understanding the epidemiology of these injuries is important for the development of targeted prevention efforts.

Prior studies of injuries in professional baseball relied on data captured by the publicly available DL. Posner and colleagues² provide one of the most comprehensive reports on MLB injuries in a report utilizing DL assignment data over a period of 7 seasons.They demonstrated that knee injuries were responsible for 7.7% (12.5% for fielders and 3.7% for pitchers) of assignments to the DL. The current study utilized a comprehensive surveillance and builds on this existing knowledge. The present study found similar trends to Posner and colleagues² in that knee injuries were responsible for 6.5% of injuries in professional baseball players that resulted in missed games. From the 2002 season to the 2008 season, knee injuries were the fifth most common reason MLB players were placed on the DL,² and the current study indicates that they remain the fifth most common reason for missed time from play based on the HITS data. Since the prevalence of these injuries have remained constant since the 2002 season, efforts to better understand these injuries are warranted in order to identify strategies to prevent them. These analyses have generated important data towards achieving this understanding.

As with most injuries in professional sports, goals for treatment are aimed at maximizing patient function and performance while minimizing time out of play. For the 2011-2014 professional baseball seasons, a total of 2171 players sustained knee injuries and missed an average of 16.2 days per injury. Knee injuries were responsible for a total of 7612 days of missed work for MLB and MiLB players per season (30,449 days over the 4-season study period). This is equivalent to a total of 20.9 years of players’ time lost in professional baseball per season over the last 4 years. The implications of this amount of time away from sport are significant, and further study should be targeted at prevention of these injuries and optimizing return to play times.

 

When attempting to reduce the burden of knee injuries in professional baseball, it may prove beneficial to first understand how the injuries occur, where on the field, and who is at greatest risk. From 2011 to 2014, nearly 44% of knee injuries occurred by noncontact mechanisms. Among all locations on the field where knee injuries occurred, those occurring in the infield were responsible for the greatest mean days missed. The players who seem to be at greatest risk for knee injuries appear to be base runners. These data suggest the need for prevention efforts targeting base runners and infield players, as well as players in MiLB, where the largest number of injuries occurred.

Recently, playing rules implemented by MLB after consultation with players have focused on reducing the number of player-to-player collisions at home plate in an attempt to decrease the injury burden to catchers and base runners.²⁰ This present analysis suggests that this rule change may also reduce the occurrence of knee injuries, as player collisions at home plate were responsible for a total of 51 knee injuries during the study period. The impact of this rule change on injury rates should also be explored. Interestingly, of the 51 knees injuries occurring due to contact at home plate, 23 occurred in 2011, and only 2 occurred in 2014—the first year of the new rule. Additional areas that resulted in high numbers of knee injuries were player-to-player contact in the infield and player contact with the ground in the infield.

Attempting to reduce injury burden and time out of play related to knee injuries in professional baseball players will likely prove to be a difficult task. In order to generate meaningful improvement, a comprehensive approach that involves players, management, trainers, therapists, and physicians will likely be required. As the first report of the epidemiology of knee injuries in professional baseball players, this study is one important step in that process. The strengths of this study are its comprehensive nature that analyzes injuries from an entire population of players on more than 200 teams over a 3-year period. Also, this research is strengthened by its focus on one particular region of the body that has received limited attention in the empirical literature, but represents a significant source of lost time during the baseball season.

There are some limitations to this study. As with any injury surveillance system, there is the possibility that not all cases were captured. Additionally, since the surveillance system is based on data from multiple teams, data entry discrepancy is possible; however, the presence of dropdown boxes and systematic definitions for injuries reduces this risk. Finally, this study did not investigate the various treatments for knee injuries beyond whether or not the injury required surgery. Since this was the first comprehensive exploration of knee injuries in professional baseball, future studies are needed to explore additional facets including outcomes related to treatment, return to play, and performance.

Conclusion

Knee injuries represent 6.5% of all injuries in professional baseball, occurring at a rate of 1.3 per 1000 AE. The burden of these injuries is significant for professional baseball players. This study fills a critical gap in sports injury research by contributing to the knowledge about the effect of knee injuries in professional baseball. It also provides an important foundation for future epidemiologic inquiry to identify modifiable risk factors and interventions that may reduce the impact of these injuries in athletes.

Tools of the Trade features reviews of the hottest new products, with surgical pearls written by surgeons who know these products best.

Arthrex, Inc. (http://www.arthrex.com)

Knee Scorpion

The Arthrex Knee Scorpion allows for simple passage of suture at the root to repair the tissue. The mechanism of the Knee Scorpion self-retrieving the suture after passage eliminates the need for another step in the procedure, which saves time. There are various types of suture configurations that can be incorporated into meniscus repairs with the Knee Scorpion. Depending on tissue quality and location, I will either pass the center of the suture to create a cinch or luggage tag type of stitch, or sometimes a simple stitch.

A challenging meniscal tear pattern that repair is particularly made easier by use of the Knee Scorpion is the radial tear of the lateral meniscus. Here it is easy to place a side-to-side “spanning” circumferential suture pattern, which is the strongest suture configuration, and it reduces the tissue very well. This approach also is ideal for variant root type tears, those that are 3 to 4 mm from the root commonly seen with the lateral meniscus associated with anterior cruciate ligament tears.

Benefits: The Knee Scorpion has a very low profile to facilitate placement in the joint with a 5º upcurve to avoid injury to the femoral condyle. The needle captures the suture after passage, which saves time and an additional surgical step. It can be used with both 0 FiberWire and 2-0 FiberWire.

Surgical pearl: Using a cannula through the working portal prevents any tissue bridge when passing and tying sutures. I prefer a Passport button cannula since its flexibility allows more access in different planes compared to a rigid type cannula.

Patrick A. Smith, MD, Columbia Orthopaedic Group, Head Section of Sports Medicine University of Missouri, Head Team Physician University of Missouri

Arthrex, Inc. (http://www.arthrex.com)

SpeedCinch

The SpeedCinch’s pistol grip design permits ergonomic, one-handed all-inside meniscal repair. It is best suited for meniscal tears of the posterior horn and body. The posterior horn of the meniscus can be repaired with the SpeedCinch inserted through either the ipsilateral or contralateral portal. Meniscal body tears, however, are best approached via a contralateral portal. The end of the device contains a 15g needle that should be advanced across the meniscus. After passage of the needle, the first implant is pushed through the needle when the trigger is fully deployed.

Next, the SpeedCinch needle should be moved at least 1 cm for placement of the second implant in either a horizontal or vertical mattress fashion. After the needle is brought to the second insertion site, the implant selector button is moved to 2 and the trigger is depressed until the first click is felt and heard. Next, the trigger is held in place after the first click and the needle is advanced across the meniscus before fully depressing the trigger, which will advance the second implant. The device is then removed and the pre-tied knot is secured with a knot pusher and then cut.

Vic Goradia, MD, G2 Orthopedics and Sports Medicine, Glen Allen, VA

Cayenne Medical, Inc. (www.cayennemedical.com)

The CrossFix II System

The CrossFix II System offers a unique, all-arthroscopic, suture-only meniscal repair that reduces the risk of chondral injury. Its “all-inside” technique uses 2 parallel suture delivery needles, available in both curved and straight designs, inserted through a single incision to provide an all-inside meniscus repair. This simple procedure can be performed in minutes via the device’s pre-tied, sliding knot, creating a “suture only” mattress stitch that replicates the repair of standard open suturing techniques. The speed and reproducibility of the repair dramatically improves operating room efficiency. Even complex tears requiring multiple sutures can be repaired in minutes.

Benefits: All-suture, no implants; single insertion; pre-tied, sliding knot. Parallel needles may be difficult to use in very tight knees.

Surgical pearl: Avoid torqueing the needles upon insertion into the meniscus.

Kenneth Montgomery, MD, Tri-County Orthopedics, Cedar Knolls, NJ.

Ceterix Orthopaedics, Inc. (www.ceterix.com)

NovoStitch Plus

The Ceterix NovoStitch Plus enables surgeons to place circumferential compression stitches around meniscus tears. These stitch patterns are designed to provide anatomical reduction and uniform compression of the tear edges, and repair the femoral surface (top) and tibial surface (bottom) of the tear with each stitch. It is also designed to eliminate neurovascular risk and avoid excessive entrapment or extrusion of the meniscus to capsule. The NovoStitch Plus passes circumferential stitches via an all-inside arthroscopic technique. In addition to anatomically repairing vertical tears, circumferential stitches also enable repair of tear types that were previously considered difficult to adequately sew.

 

Benefits: Passes both sides of the stitch with 1 insertion (avoids tissue bridges and girth hitches). Retractable lower jaw (allows access to tight knees, and allows removal from knees with mobile menisci). Needle extends into the posterior gutter through the tip of the lower jaw (does not touch chondral surfaces). Smaller lower jaw tooth (easier insertion of the lower jaw under the meniscus). Upper jaw curved to follow the shape contour of the femoral side of the meniscus and femoral condyle. Compared to hybrid all-inside devices, inside-out and outside-in repairs. Enables anatomical reduction and uniform compression. Each stitch repairs the top and bottom of the tear. Designed to eliminate neurovascular risk. Avoids excessive capsular entrapment. Repairs effectively in front of the popliteal hiatus. Enables side-to-side radial tear repair, and top-to-bottom horizontal tear repair. Significantly smaller needle than used by hybrid all-inside devices.

Surgical pearl: A spinal needle should be used to establish the skin incision location of the working portal. The optimal skin incision location is one where a spinal needle can be inserted such that the distal end of the needle is parallel to the region of the tibial plateau under the meniscus.

Justin Saliman, MD, Cedars-Sinai Orthopaedic Center, Los Angeles CA

Mitek Sports Medicine (www.depuysynthes.com)

Mitek Omnispan

The Mitek Omnispan Meniscal Repair System is an all-inside arthroscopic meniscal repair device. It consists of a low profile needle, pre-loaded with 2 PEEK backstops and No. 2/0 Orthocord High Strength Orthopaedic Suture, which is delivered using the Omnispan System Applier. The needles come in 3 angles (0°, 12°, and 27°) and the Applier is a single-patient, multi-use design, meaning the same Applier can be used for multiple implants with a single patient. The needles also have a safety sleeve over each set of implants to prevent delivery failure. Once the needle is attached to the Applier, the device is inserted into the knee. Using the gray trigger, the first implant is delivered into the meniscocapsular region. The red trigger is then pulled, advancing the second implant. Once appropriate positioning of the second implant is determined, the gray trigger is fired again. The surgeon pulls on the sliding knot advancing the suture through the implants creating a suture bridge over the tear. The final repair consists of Orthocord Suture spanning the meniscus, while the PEEK backstops are embedded in the meniscocapsular area only.

Surgical pearls:

An adequate portal opening is paramount for successful implementation. I widen my portal with an instrument clamp to allow easy passage of the Applier. It is usually necessary to switch the camera back and forth between both portals to gain access to the angles needed to create the repair. I also always use a skid when inserting the Applier to prevent soft tissue impingement.

The surgeon should always check to make sure the implant is properly loaded on the back table, ensuring it is fully inserted into the locking mechanism and loaded in the correct direction.

The surgeon should hold the Applier firmly when firing the gray trigger, as some kick-back does occur.

The Applier should remain in the joint throughout the advancing and deployment of implants, so the surgeon can maintain visualization with the scope. Once the implants are in position, I then remove the Applier from the joint space.

Use a probe to place counter-pressure on the meniscus when tightening the suture. The sliding suture system is a double-loop design. In order to smoothly advance the suture, I recommend that a probe be placed on the smaller loop closest to the meniscus, so that when the suture is tightened, the probe is under the smaller loop. A gentle back-and-forth pulling maneuver between the free suture and the probe creates a smooth transition during tightening.

Scott A. Sigman, MD, Chief of Orthopedics, Lowell General Hospital; Team Physician, UMass Lowell

Smith & Nephew Inc. (www.smith-nephew.com)

FAST-FIX 360

The FAST-FIX360 design enables you to deploy implants in any hand position—vertically, horizontally on either side of the meniscus—with a fast, smooth advancing motion. This spring-action design facilitates the advancement of each implant into the capsule. Smaller implants and pre-tied, self-sliding knots made of ULTRABRAID 2-0 Suture create smaller needle insertions, reducing disruption to the meniscus. Low-profile, stiffer needle shaft improves control while enabling access and visibility to hard-to-reach areas of the meniscus. Set needle depth penetration from 10 mm to 18 mm with the push of a button. The FAST-FIX 360 System has biomechanical properties that best reproduce the vertical mattress suture technique.

Surgical pearl: Assess tear pattern and reparability, then reduce and template repair construct and suture points. Precisely select portal insertion sites, ensuring perpendicular vector needle delivery at the repair site. Measure the meniscal fragment size and rim width, setting the depth penetration limiter (usually set to 15 to 18 mm). Insert first anchor posteriorly and superiorly or away from the insertion portal and then after deployment, insert the second anchor anteriorly and inferiorly or into the “near” tear fragment. Tension the suture using the knot pusher/cutter as a “suture stent” to manually “pull and push” the suture, compressing the repair construct and coapting the tear. Avoid “over-repairing” the tear by spacing out sutures at 3 mm to 5 mm and alternating femoral and tibial undersurface placement.

 

Nicholas A. Sgaglione, MD (pictured), and Ryan A. Harrell, DO

Tools of the Trade features reviews of the hottest new products, with surgical pearls written by surgeons who know these products best.

Arthrex, Inc. (http://www.arthrex.com)

Knee Scorpion

The Arthrex Knee Scorpion allows for simple passage of suture at the root to repair the tissue. The mechanism of the Knee Scorpion self-retrieving the suture after passage eliminates the need for another step in the procedure, which saves time. There are various types of suture configurations that can be incorporated into meniscus repairs with the Knee Scorpion. Depending on tissue quality and location, I will either pass the center of the suture to create a cinch or luggage tag type of stitch, or sometimes a simple stitch.

A challenging meniscal tear pattern that repair is particularly made easier by use of the Knee Scorpion is the radial tear of the lateral meniscus. Here it is easy to place a side-to-side “spanning” circumferential suture pattern, which is the strongest suture configuration, and it reduces the tissue very well. This approach also is ideal for variant root type tears, those that are 3 to 4 mm from the root commonly seen with the lateral meniscus associated with anterior cruciate ligament tears.

Benefits: The Knee Scorpion has a very low profile to facilitate placement in the joint with a 5º upcurve to avoid injury to the femoral condyle. The needle captures the suture after passage, which saves time and an additional surgical step. It can be used with both 0 FiberWire and 2-0 FiberWire.

Surgical pearl: Using a cannula through the working portal prevents any tissue bridge when passing and tying sutures. I prefer a Passport button cannula since its flexibility allows more access in different planes compared to a rigid type cannula.

Patrick A. Smith, MD, Columbia Orthopaedic Group, Head Section of Sports Medicine University of Missouri, Head Team Physician University of Missouri

Arthrex, Inc. (http://www.arthrex.com)

SpeedCinch

The SpeedCinch’s pistol grip design permits ergonomic, one-handed all-inside meniscal repair. It is best suited for meniscal tears of the posterior horn and body. The posterior horn of the meniscus can be repaired with the SpeedCinch inserted through either the ipsilateral or contralateral portal. Meniscal body tears, however, are best approached via a contralateral portal. The end of the device contains a 15g needle that should be advanced across the meniscus. After passage of the needle, the first implant is pushed through the needle when the trigger is fully deployed.

Next, the SpeedCinch needle should be moved at least 1 cm for placement of the second implant in either a horizontal or vertical mattress fashion. After the needle is brought to the second insertion site, the implant selector button is moved to 2 and the trigger is depressed until the first click is felt and heard. Next, the trigger is held in place after the first click and the needle is advanced across the meniscus before fully depressing the trigger, which will advance the second implant. The device is then removed and the pre-tied knot is secured with a knot pusher and then cut.

Vic Goradia, MD, G2 Orthopedics and Sports Medicine, Glen Allen, VA

Cayenne Medical, Inc. (www.cayennemedical.com)

The CrossFix II System

The CrossFix II System offers a unique, all-arthroscopic, suture-only meniscal repair that reduces the risk of chondral injury. Its “all-inside” technique uses 2 parallel suture delivery needles, available in both curved and straight designs, inserted through a single incision to provide an all-inside meniscus repair. This simple procedure can be performed in minutes via the device’s pre-tied, sliding knot, creating a “suture only” mattress stitch that replicates the repair of standard open suturing techniques. The speed and reproducibility of the repair dramatically improves operating room efficiency. Even complex tears requiring multiple sutures can be repaired in minutes.

Benefits: All-suture, no implants; single insertion; pre-tied, sliding knot. Parallel needles may be difficult to use in very tight knees.

Surgical pearl: Avoid torqueing the needles upon insertion into the meniscus.

Kenneth Montgomery, MD, Tri-County Orthopedics, Cedar Knolls, NJ.

Ceterix Orthopaedics, Inc. (www.ceterix.com)

NovoStitch Plus

The Ceterix NovoStitch Plus enables surgeons to place circumferential compression stitches around meniscus tears. These stitch patterns are designed to provide anatomical reduction and uniform compression of the tear edges, and repair the femoral surface (top) and tibial surface (bottom) of the tear with each stitch. It is also designed to eliminate neurovascular risk and avoid excessive entrapment or extrusion of the meniscus to capsule. The NovoStitch Plus passes circumferential stitches via an all-inside arthroscopic technique. In addition to anatomically repairing vertical tears, circumferential stitches also enable repair of tear types that were previously considered difficult to adequately sew.

 

Benefits: Passes both sides of the stitch with 1 insertion (avoids tissue bridges and girth hitches). Retractable lower jaw (allows access to tight knees, and allows removal from knees with mobile menisci). Needle extends into the posterior gutter through the tip of the lower jaw (does not touch chondral surfaces). Smaller lower jaw tooth (easier insertion of the lower jaw under the meniscus). Upper jaw curved to follow the shape contour of the femoral side of the meniscus and femoral condyle. Compared to hybrid all-inside devices, inside-out and outside-in repairs. Enables anatomical reduction and uniform compression. Each stitch repairs the top and bottom of the tear. Designed to eliminate neurovascular risk. Avoids excessive capsular entrapment. Repairs effectively in front of the popliteal hiatus. Enables side-to-side radial tear repair, and top-to-bottom horizontal tear repair. Significantly smaller needle than used by hybrid all-inside devices.

Surgical pearl: A spinal needle should be used to establish the skin incision location of the working portal. The optimal skin incision location is one where a spinal needle can be inserted such that the distal end of the needle is parallel to the region of the tibial plateau under the meniscus.

Justin Saliman, MD, Cedars-Sinai Orthopaedic Center, Los Angeles CA

Mitek Sports Medicine (www.depuysynthes.com)

Mitek Omnispan

The Mitek Omnispan Meniscal Repair System is an all-inside arthroscopic meniscal repair device. It consists of a low profile needle, pre-loaded with 2 PEEK backstops and No. 2/0 Orthocord High Strength Orthopaedic Suture, which is delivered using the Omnispan System Applier. The needles come in 3 angles (0°, 12°, and 27°) and the Applier is a single-patient, multi-use design, meaning the same Applier can be used for multiple implants with a single patient. The needles also have a safety sleeve over each set of implants to prevent delivery failure. Once the needle is attached to the Applier, the device is inserted into the knee. Using the gray trigger, the first implant is delivered into the meniscocapsular region. The red trigger is then pulled, advancing the second implant. Once appropriate positioning of the second implant is determined, the gray trigger is fired again. The surgeon pulls on the sliding knot advancing the suture through the implants creating a suture bridge over the tear. The final repair consists of Orthocord Suture spanning the meniscus, while the PEEK backstops are embedded in the meniscocapsular area only.

Surgical pearls:

An adequate portal opening is paramount for successful implementation. I widen my portal with an instrument clamp to allow easy passage of the Applier. It is usually necessary to switch the camera back and forth between both portals to gain access to the angles needed to create the repair. I also always use a skid when inserting the Applier to prevent soft tissue impingement.

The surgeon should always check to make sure the implant is properly loaded on the back table, ensuring it is fully inserted into the locking mechanism and loaded in the correct direction.

The surgeon should hold the Applier firmly when firing the gray trigger, as some kick-back does occur.

The Applier should remain in the joint throughout the advancing and deployment of implants, so the surgeon can maintain visualization with the scope. Once the implants are in position, I then remove the Applier from the joint space.

Use a probe to place counter-pressure on the meniscus when tightening the suture. The sliding suture system is a double-loop design. In order to smoothly advance the suture, I recommend that a probe be placed on the smaller loop closest to the meniscus, so that when the suture is tightened, the probe is under the smaller loop. A gentle back-and-forth pulling maneuver between the free suture and the probe creates a smooth transition during tightening.

Scott A. Sigman, MD, Chief of Orthopedics, Lowell General Hospital; Team Physician, UMass Lowell

Smith & Nephew Inc. (www.smith-nephew.com)

FAST-FIX 360

The FAST-FIX360 design enables you to deploy implants in any hand position—vertically, horizontally on either side of the meniscus—with a fast, smooth advancing motion. This spring-action design facilitates the advancement of each implant into the capsule. Smaller implants and pre-tied, self-sliding knots made of ULTRABRAID 2-0 Suture create smaller needle insertions, reducing disruption to the meniscus. Low-profile, stiffer needle shaft improves control while enabling access and visibility to hard-to-reach areas of the meniscus. Set needle depth penetration from 10 mm to 18 mm with the push of a button. The FAST-FIX 360 System has biomechanical properties that best reproduce the vertical mattress suture technique.

Surgical pearl: Assess tear pattern and reparability, then reduce and template repair construct and suture points. Precisely select portal insertion sites, ensuring perpendicular vector needle delivery at the repair site. Measure the meniscal fragment size and rim width, setting the depth penetration limiter (usually set to 15 to 18 mm). Insert first anchor posteriorly and superiorly or away from the insertion portal and then after deployment, insert the second anchor anteriorly and inferiorly or into the “near” tear fragment. Tension the suture using the knot pusher/cutter as a “suture stent” to manually “pull and push” the suture, compressing the repair construct and coapting the tear. Avoid “over-repairing” the tear by spacing out sutures at 3 mm to 5 mm and alternating femoral and tibial undersurface placement.

 

Nicholas A. Sgaglione, MD (pictured), and Ryan A. Harrell, DO

Tools of the Trade features reviews of the hottest new products, with surgical pearls written by surgeons who know these products best.

Arthrex, Inc. (http://www.arthrex.com)

Knee Scorpion

The Arthrex Knee Scorpion allows for simple passage of suture at the root to repair the tissue. The mechanism of the Knee Scorpion self-retrieving the suture after passage eliminates the need for another step in the procedure, which saves time. There are various types of suture configurations that can be incorporated into meniscus repairs with the Knee Scorpion. Depending on tissue quality and location, I will either pass the center of the suture to create a cinch or luggage tag type of stitch, or sometimes a simple stitch.

A challenging meniscal tear pattern that repair is particularly made easier by use of the Knee Scorpion is the radial tear of the lateral meniscus. Here it is easy to place a side-to-side “spanning” circumferential suture pattern, which is the strongest suture configuration, and it reduces the tissue very well. This approach also is ideal for variant root type tears, those that are 3 to 4 mm from the root commonly seen with the lateral meniscus associated with anterior cruciate ligament tears.

Benefits: The Knee Scorpion has a very low profile to facilitate placement in the joint with a 5º upcurve to avoid injury to the femoral condyle. The needle captures the suture after passage, which saves time and an additional surgical step. It can be used with both 0 FiberWire and 2-0 FiberWire.

Surgical pearl: Using a cannula through the working portal prevents any tissue bridge when passing and tying sutures. I prefer a Passport button cannula since its flexibility allows more access in different planes compared to a rigid type cannula.

Patrick A. Smith, MD, Columbia Orthopaedic Group, Head Section of Sports Medicine University of Missouri, Head Team Physician University of Missouri

Arthrex, Inc. (http://www.arthrex.com)

SpeedCinch

The SpeedCinch’s pistol grip design permits ergonomic, one-handed all-inside meniscal repair. It is best suited for meniscal tears of the posterior horn and body. The posterior horn of the meniscus can be repaired with the SpeedCinch inserted through either the ipsilateral or contralateral portal. Meniscal body tears, however, are best approached via a contralateral portal. The end of the device contains a 15g needle that should be advanced across the meniscus. After passage of the needle, the first implant is pushed through the needle when the trigger is fully deployed.

Next, the SpeedCinch needle should be moved at least 1 cm for placement of the second implant in either a horizontal or vertical mattress fashion. After the needle is brought to the second insertion site, the implant selector button is moved to 2 and the trigger is depressed until the first click is felt and heard. Next, the trigger is held in place after the first click and the needle is advanced across the meniscus before fully depressing the trigger, which will advance the second implant. The device is then removed and the pre-tied knot is secured with a knot pusher and then cut.

Vic Goradia, MD, G2 Orthopedics and Sports Medicine, Glen Allen, VA

Cayenne Medical, Inc. (www.cayennemedical.com)

The CrossFix II System

The CrossFix II System offers a unique, all-arthroscopic, suture-only meniscal repair that reduces the risk of chondral injury. Its “all-inside” technique uses 2 parallel suture delivery needles, available in both curved and straight designs, inserted through a single incision to provide an all-inside meniscus repair. This simple procedure can be performed in minutes via the device’s pre-tied, sliding knot, creating a “suture only” mattress stitch that replicates the repair of standard open suturing techniques. The speed and reproducibility of the repair dramatically improves operating room efficiency. Even complex tears requiring multiple sutures can be repaired in minutes.

Benefits: All-suture, no implants; single insertion; pre-tied, sliding knot. Parallel needles may be difficult to use in very tight knees.

Surgical pearl: Avoid torqueing the needles upon insertion into the meniscus.

Kenneth Montgomery, MD, Tri-County Orthopedics, Cedar Knolls, NJ.

Ceterix Orthopaedics, Inc. (www.ceterix.com)

NovoStitch Plus

The Ceterix NovoStitch Plus enables surgeons to place circumferential compression stitches around meniscus tears. These stitch patterns are designed to provide anatomical reduction and uniform compression of the tear edges, and repair the femoral surface (top) and tibial surface (bottom) of the tear with each stitch. It is also designed to eliminate neurovascular risk and avoid excessive entrapment or extrusion of the meniscus to capsule. The NovoStitch Plus passes circumferential stitches via an all-inside arthroscopic technique. In addition to anatomically repairing vertical tears, circumferential stitches also enable repair of tear types that were previously considered difficult to adequately sew.

 

Benefits: Passes both sides of the stitch with 1 insertion (avoids tissue bridges and girth hitches). Retractable lower jaw (allows access to tight knees, and allows removal from knees with mobile menisci). Needle extends into the posterior gutter through the tip of the lower jaw (does not touch chondral surfaces). Smaller lower jaw tooth (easier insertion of the lower jaw under the meniscus). Upper jaw curved to follow the shape contour of the femoral side of the meniscus and femoral condyle. Compared to hybrid all-inside devices, inside-out and outside-in repairs. Enables anatomical reduction and uniform compression. Each stitch repairs the top and bottom of the tear. Designed to eliminate neurovascular risk. Avoids excessive capsular entrapment. Repairs effectively in front of the popliteal hiatus. Enables side-to-side radial tear repair, and top-to-bottom horizontal tear repair. Significantly smaller needle than used by hybrid all-inside devices.

Surgical pearl: A spinal needle should be used to establish the skin incision location of the working portal. The optimal skin incision location is one where a spinal needle can be inserted such that the distal end of the needle is parallel to the region of the tibial plateau under the meniscus.

Justin Saliman, MD, Cedars-Sinai Orthopaedic Center, Los Angeles CA

Mitek Sports Medicine (www.depuysynthes.com)

Mitek Omnispan

The Mitek Omnispan Meniscal Repair System is an all-inside arthroscopic meniscal repair device. It consists of a low profile needle, pre-loaded with 2 PEEK backstops and No. 2/0 Orthocord High Strength Orthopaedic Suture, which is delivered using the Omnispan System Applier. The needles come in 3 angles (0°, 12°, and 27°) and the Applier is a single-patient, multi-use design, meaning the same Applier can be used for multiple implants with a single patient. The needles also have a safety sleeve over each set of implants to prevent delivery failure. Once the needle is attached to the Applier, the device is inserted into the knee. Using the gray trigger, the first implant is delivered into the meniscocapsular region. The red trigger is then pulled, advancing the second implant. Once appropriate positioning of the second implant is determined, the gray trigger is fired again. The surgeon pulls on the sliding knot advancing the suture through the implants creating a suture bridge over the tear. The final repair consists of Orthocord Suture spanning the meniscus, while the PEEK backstops are embedded in the meniscocapsular area only.

Surgical pearls:

An adequate portal opening is paramount for successful implementation. I widen my portal with an instrument clamp to allow easy passage of the Applier. It is usually necessary to switch the camera back and forth between both portals to gain access to the angles needed to create the repair. I also always use a skid when inserting the Applier to prevent soft tissue impingement.

The surgeon should always check to make sure the implant is properly loaded on the back table, ensuring it is fully inserted into the locking mechanism and loaded in the correct direction.

The surgeon should hold the Applier firmly when firing the gray trigger, as some kick-back does occur.

The Applier should remain in the joint throughout the advancing and deployment of implants, so the surgeon can maintain visualization with the scope. Once the implants are in position, I then remove the Applier from the joint space.

Use a probe to place counter-pressure on the meniscus when tightening the suture. The sliding suture system is a double-loop design. In order to smoothly advance the suture, I recommend that a probe be placed on the smaller loop closest to the meniscus, so that when the suture is tightened, the probe is under the smaller loop. A gentle back-and-forth pulling maneuver between the free suture and the probe creates a smooth transition during tightening.

Scott A. Sigman, MD, Chief of Orthopedics, Lowell General Hospital; Team Physician, UMass Lowell

Smith & Nephew Inc. (www.smith-nephew.com)

FAST-FIX 360

The FAST-FIX360 design enables you to deploy implants in any hand position—vertically, horizontally on either side of the meniscus—with a fast, smooth advancing motion. This spring-action design facilitates the advancement of each implant into the capsule. Smaller implants and pre-tied, self-sliding knots made of ULTRABRAID 2-0 Suture create smaller needle insertions, reducing disruption to the meniscus. Low-profile, stiffer needle shaft improves control while enabling access and visibility to hard-to-reach areas of the meniscus. Set needle depth penetration from 10 mm to 18 mm with the push of a button. The FAST-FIX 360 System has biomechanical properties that best reproduce the vertical mattress suture technique.

Surgical pearl: Assess tear pattern and reparability, then reduce and template repair construct and suture points. Precisely select portal insertion sites, ensuring perpendicular vector needle delivery at the repair site. Measure the meniscal fragment size and rim width, setting the depth penetration limiter (usually set to 15 to 18 mm). Insert first anchor posteriorly and superiorly or away from the insertion portal and then after deployment, insert the second anchor anteriorly and inferiorly or into the “near” tear fragment. Tension the suture using the knot pusher/cutter as a “suture stent” to manually “pull and push” the suture, compressing the repair construct and coapting the tear. Avoid “over-repairing” the tear by spacing out sutures at 3 mm to 5 mm and alternating femoral and tibial undersurface placement.

 

Nicholas A. Sgaglione, MD (pictured), and Ryan A. Harrell, DO

Rotator cuff injuries can be a source of debilitating pain and dysfunction in athletes at all levels, occasionally precluding return to competitive sport. Overhead athletes place extraordinary physiologic demands on the shoulder, as humeral angular velocities of 7000° to 8000° per second and rotational torques higher than 70 Nm have been measured during the baseball pitch.¹ Repetitive supraphysiologic loading of the rotator cuff throughout the coordinated phases of throwing can result in a characteristic spectrum of shoulder pathology in overhead throwers. Several studies have demonstrated partial-thickness articular-sided rotator cuff tears (RCTs) in the area of the posterior supraspinatus and anterior infraspinatus tendons.^2-4 Although the precise mechanism remains unclear, plausible explanations for the pathogenesis of these injuries include eccentric tensile and shear forces that lead to tendon failure with repetitive throwing, as well as internal impingement (mechanical impingement of the aforementioned tendons against the posterosuperior glenoid at 90° of shoulder abduction and maximum external rotation).^5,6

Whereas partial-thickness articular-sided RCTs have been described in overhead athletes with rotator cuff pathology, full-thickness tears are encountered less often.^7,8 Accordingly, there is a paucity of literature on clinical outcomes in professional baseball players with these injuries. To our knowledge, only 2 studies have investigated functional outcomes of open surgical repair of full-thickness tears in this population, and the outcomes have been uniformly poor.^8,9

An anatomical description of rotator cuff anatomy has demonstrated a consistent pattern of supraspinatus and infraspinatus tendon insertion relative to the articular surface, biceps groove, and the bare area of the humerus.¹⁰ Using gross and microscopic analyses, the authors noted that the supraspinatus tendon inserted immediately adjacent to the articular margin, and the infraspinatus and teres minor tapered laterally away from the margin to form the bare area. Detailed knowledge of the insertional anatomy of the rotator cuff is important, as surgical repair should recreate the broad footprint to restore normal biomechanics and increase the surface area available for healing.^11,12 Medial advancement of the rotator cuff insertion during surgical repair can have deleterious biomechanical effects on glenohumeral motion.¹¹

Given the unfavorable results found after routine open repair of full-thickness tears, we altered our approach to these injuries and adopted an arthroscopic technique in which the tendon is repaired immediately lateral to the anatomical footprint. Research studies have demonstrated that chronic stress from repetitive throwing can lead to attenuation of soft-tissue restraints, and we think preservation of these adaptive changes after surgical repair may be important for these athletes to maintain extraordinary glenohumeral rotation and achieve high throwing velocities.¹³ We conducted a study to describe the lateralized repair technique for full-thickness RCTs and to report functional outcomes in Major League Baseball (MLB) pitchers treated with this procedure at minimum 2-year follow-up. We hypothesized that use of this novel technique would result in a higher rate of return to preinjury level of play in comparison with open rotator cuff repair in comparable cohorts, as reported in other studies.^8,9

Materials and Methods

After obtaining Institutional Review Board approval for this study, we performed a retrospective chart review of MLB players treated by Dr. Altchek. We identified all professional baseball players who received a diagnosis of full-thickness RCT after preoperative magnetic resonance imaging with subsequent confirmation during surgery. Any patient who underwent arthroscopic repair using the lateralized footprint technique was included in the study. Demographic and preoperative injury information was collected from the chart, and final follow-up data were collected at the last available clinic visit. From available team records, we also obtained return-to-play data and objective pitching statistics: seasons played, games played, innings pitched, strikeouts per 9 innings, walks per 9 innings, and earned run average.

Surgical Technique

We routinely perform arthroscopic rotator cuff repairs with the patient under regional anesthesia in the beach-chair position. The operative extremity is placed in a Spider Limb Positioner (Smith & Nephew) to facilitate easy manipulation of the arm throughout the procedure. A standard posterior portal is established, and then an anterior portal is placed in the superolateral aspect of the rotator interval directly anterior to the leading edge of the supraspinatus tendon. A lateral portal created 2 to 3 cm distal to the anterolateral margin of the acromion may be used as an additional working portal. A thorough diagnostic arthroscopy is performed to evaluate the glenohumeral joint for any concomitant intra-articular pathology. Particular attention is directed to inspection of the superior labrum, biceps tendon, and capsuloligamentous structures, as injuries to these structures are often associated with rotator cuff pathology in overhead athletes.

Once presence of an RCT is confirmed, a thorough subacromial bursectomy is performed to help with visualization and inspection of the injury. The tissue is provisionally grasped and mobilized to measure the amount of available tendon excursion. In this unique population, the vast majority of injuries are diagnosed in an expeditious manner, thereby precluding the presence of significant retraction, poor tissue quality, and inadequate mobilization of the tendons. The greater tuberosity is identified, and the area immediately adjacent to the articular margin is abraded with a mechanical shaver to enhance healing potential. For supraspinatus tears, an anchor is placed immediately lateral to the articular margin in the region of the anterior attachment of the rotator cable (Figure 1). The posterior anchor is placed about 10 to 15 mm lateral to the articular margin to reattach the infraspinatus tendon (Figure 2). When the medial row sutures are tied down, anatomical placement of these anchors effectively re-creates the bare area described by Curtis and colleagues¹⁰ (Figure 3). In most cases, the medial row sutures are left intact and fixed laterally with a knotless anchor to provide a transosseous equivalent (double-row) repair.

 

 

 

Results

We identified 6 MLB pitchers who underwent arthroscopic rotator cuff repair using the aforementioned technique over an 8-year period. Each patient presented with complaints of debilitating shoulder pain and decreased pitching performance, including loss of throwing accuracy and velocity. There were 4 right-hand–dominant pitchers and 2 left-hand–dominant pitchers; rotator cuff pathology was observed in the dominant pitching arm in each case. Three players were classified as starting pitchers; the other 3 pitched in a relief role. Mean age of all pitchers at time of surgery was 29.8 years (range, 25-37 years). According to records, 2 patients (33%) underwent previous rotator cuff débridement for partial-thickness RCTs before surgical intervention at our institution. Operative information on the depth of the partial-thickness tears observed during the previous procedures was not available for review. At time of rotator cuff repair, 3 patients (50%) underwent concomitant procedures, including superior labrum anterior-posterior (SLAP) lesion repair (1 patient) and posterior labrum débridement (2 patients). A double-row fixation construct was achieved in each case. Review of operative records revealed a mean tear size of 2.1 cm (range, 1.5-3.0 cm) measured anterior to posterior, and all tears involved the supraspinatus and/or infraspinatus tendons. Postoperative rehabilitation included immobilization in a sling for 4 weeks. Hand, wrist, and elbow range-of-motion (ROM) exercises were started immediately to help reduce inflammation. Passive ROM exercises in the plane of the scapula were begun 4 weeks after surgery. Isometric scapular stabilization exercises were also incorporated at that time. Active-assisted ROM exercises were started at about 6 weeks, and isometric strengthening exercises were started at week 8 with progression to eccentric strengthening and weight training at about 3 months. Most pitchers were allowed to begin an interval throwing program at 24 weeks. There were no significant differences in the therapy programs for pitchers who underwent concomitant labral procedures, but the patient who underwent SLAP repair was limited to 30° of external rotation and 90° of forward flexion, with avoidance of active biceps contractions, for the first 6 weeks of rehabilitation.

By mean follow-up of 66.7 months (range, 23.2-94.6 months), 5 pitchers (83%) returned to their preinjury level of competition for at least 1 full season. One player pitched at Minor League Class AA level for about 1 season but was forced to retire because of persistent symptoms related to the shoulder. This pitcher underwent simultaneous rotator cuff and SLAP lesion repair. Of the 5 pitchers who resumed MLB play, none returned to their preoperative pitching productivity; mean number of innings pitched decreased from 1806.5 to 183.7. Three (60%) of these 5 pitchers experienced a slight reduction in performance as measured by earned run average. Interestingly, both players over age 30 years at time of surgery, versus 3 of the 4 pitchers under age 30 years, returned to their preoperative level of competition for at least 1 season. The Table summarizes MLB player data and objective pitching statistics. There were no perioperative complications related to this arthroscopic technique, and there were no glenohumeral ROM deficits at final follow-up.

Discussion

Although the incidence of full-thickness RCTs in professional baseball players is presumably low, available studies suggest that it is a debilitating injury with a poor prognosis for return to high-level athletics. Mazoué and Andrews⁹ reviewed the outcomes of 16 professional baseball players (12 pitchers, 4 position players) who underwent mini-open repair of full-thickness RCTs that involved more than 90% of the rotator cuff. Fifteen patients underwent mini-open rotator cuff repair using suture anchors in the anatomical footprint along with bone tunnels established near the lateral margin of the greater tuberosity to create a 2-level anatomical repair. One patient was treated with a mini-open repair using suture anchors in the greater tuberosity with a side-side repair of a longitudinal split within the rotator cuff. In the evaluation of outcomes by player position, only 1 pitcher (8%) returned to a competitive level of pitching at a mean follow-up of 67 months. On review of 2 position players with a full-thickness RCT in the dominant shoulder, only 1 (50%) returned to Major League play at a mean follow-up of 62.5 months. The remaining 2 position players underwent surgical repair of the nondominant shoulder, and, not surprisingly, both returned to their previous level of athletic activity without any difficulty. These results should be examined carefully, as the associated pathology in this high-demand cohort should not be discounted. Eleven (almost 92%) of the 12 pitchers had undergone at least 1 previous procedure on the shoulder. Furthermore, at time of full-thickness rotator cuff repair, 9 (75%) of the 12 pitchers were treated for concomitant intra-articular pathology, including SLAP tears, capsular attenuation, and/or labral fraying. In our study, 50% of pitchers underwent an associated labral procedure. Although labral débridement did not have a significant effect on return to play, the 1 pitcher who underwent SLAP repair was not able to return to preinjury level of play.

 

Tibone and colleagues⁸ reviewed postoperative outcomes in 45 athletes with rotator cuff pathology. Within their series, 5 professional baseball pitchers with full-thickness tears were treated with open subacromial decompression and rotator cuff repair. Two baseball pitchers with RCTs larger than 2 cm underwent open transosseous footprint repair in which the cuff was reinserted using bone tunnels created within the greater tuberosity. At long-term follow-up, only 2 (40%) of the 5 pitchers returned to competitive pitching. Interestingly, both pitchers who underwent transosseous footprint fixation were unable to return to professional baseball.

Overhead athletes require a delicate balance of shoulder mobility and stability to meet the high functional demands of their sports. Significant debate continues as to whether innate alterations in glenohumeral mobility preselect individuals for overhead sports, or if these changes are acquired through adaptations in supporting soft-tissue and osseous structures. Sethi and colleagues¹⁴ used an instrumented manual laxity examination to compare anterior-posterior laxity in asymptomatic professional and Division I college baseball players. The authors noted asymmetric anterior-posterior translation (>3 mm) between the throwing shoulder and the nondominant shoulder in 12 (60%) of 20 professional pitchers and 10 (59%) of 17 college pitchers. Although the authors did not correlate translational differences with corresponding shoulder pathology, the observed asymmetry supported the idea that these athletes may experience adaptive glenohumeral changes with repetitive throwing. The association between adaptive changes and shoulder biomechanics has been studied. Burkhart and Lo¹⁵ used a cadaveric model to describe the cam effect of the proximal humerus and the biomechanical consequences of a relative reduction in this effect after pathologic changes within the glenohumeral joint (constriction of posteroinferior capsule). They noted that a posterosuperior shift in the glenohumeral contact point in the throwing position can result in anterior capsular redundancy that may contribute to microinstability of the shoulder. This relative laxity increases external rotation, resulting in increased torsional and shear forces at the rotator cuff insertion.¹⁶ Ultimately, these abnormal forces may predispose overhead athletes to rotator cuff injury.

Given the available literature, it is clear that full-thickness RCTs are potentially career-ending injuries for professional baseball players. The question arises as to why the results are so poor. Ultimately, the high incidence of concomitant intra-articular pathology associated with full-thickness RCTs underscores the severity of soft-tissue damage sustained with repetitive overhead throwing. Mazoué and Andrews⁹ proposed the presence of associated labral and capsular pathology as a potential explanation for poor outcomes of surgical repair. Given the myriad of additional pathology observed in each patient, it is difficult to ascertain the precise impact of these injuries on postoperative outcome. However, early diagnosis and aggressive surgical intervention are clearly necessary to prevent accumulative injury. Regarding surgical intervention, both Tibone and colleagues⁸ and Mazoué and Andrews⁹ reported use of an open surgical repair technique in which the tendon was repaired to the anatomical footprint. Certainly, the benefits of an all-arthroscopic technique include optimal visualization of the RCT, less perioperative morbidity, and minimal soft-tissue injury. With our arthroscopic technique, the rotator cuff was fixed immediately lateral to the anatomical footprint, thereby leaving the medial aspect of the footprint uncovered. Functionally, the goal of this procedure is to restore the integrity of the rotator cuff without compromising glenohumeral mobility acquired through soft-tissue adaptation. Investigation of the insertional anatomy of the rotator cuff has demonstrated that the supraspinatus tendon inserts about 0.9 mm from the edge of the articular surface, and the infraspinatus insertional footprint tapers away from the articular surface to form the bare area as it extends inferiorly on the greater tuberosity.¹⁰ We think preexisting adaptations in glenohumeral anatomy are important for peak performance in this unique population, and even small alterations in the repair location can have deleterious effects on throwing mechanics. Lateralized repair of the cuff precludes potential medialization of the cuff insertion and may facilitate preservation of soft-tissue adaptations that these athletes rely on to achieve extraordinary glenohumeral motion.

Interestingly, with this technique we noted a higher rate of return to MLB play in pitchers over age 30 years. Although several individual factors (eg, player talent level, work ethics, compliance with rehabilitation) may play a role in this finding, it is possible that older, more mature patients may be more willing to assume diminished roles to continue to play. Jones and colleagues¹⁷ recently reported similar findings in older MLB pitchers after revision ulnar collateral ligament reconstruction.

This study had several limitations. First, the patient cohort was small (a result of the nature and relatively infrequent incidence of the clinical problem). Second, clinical information was collected retrospectively, which limited our ability to determine precise differences between preoperative and postoperative glenohumeral ROM with this technique. Third, the cohort included patients who demonstrated additional intra-articular (labral) pathology. Although associated pathology is common in this high-demand athletic population, it is clear that advanced pathology (eg, SLAP tears) may affect clinical outcomes, as in our study. Despite these limitations, our study is the largest review of professional baseball players treated for full-thickness rotator cuff injuries with an arthroscopic technique. Overall, the results of this study are promising and call for further clinical and biomechanical evaluation.

 

Conclusion

Surgical management of rotator cuff injuries in professional baseball players remains an extremely difficult problem. Current studies of full-thickness RCTs highlight these athletes’ poor functional outcomes. These unfavorable results prompted us to alter our surgical technique. Initial outcomes have been encouraging, and extended follow-up in this cohort of patients will provide a more definitive assessment of the success of this technique.

Rotator cuff injuries can be a source of debilitating pain and dysfunction in athletes at all levels, occasionally precluding return to competitive sport. Overhead athletes place extraordinary physiologic demands on the shoulder, as humeral angular velocities of 7000° to 8000° per second and rotational torques higher than 70 Nm have been measured during the baseball pitch.¹ Repetitive supraphysiologic loading of the rotator cuff throughout the coordinated phases of throwing can result in a characteristic spectrum of shoulder pathology in overhead throwers. Several studies have demonstrated partial-thickness articular-sided rotator cuff tears (RCTs) in the area of the posterior supraspinatus and anterior infraspinatus tendons.^2-4 Although the precise mechanism remains unclear, plausible explanations for the pathogenesis of these injuries include eccentric tensile and shear forces that lead to tendon failure with repetitive throwing, as well as internal impingement (mechanical impingement of the aforementioned tendons against the posterosuperior glenoid at 90° of shoulder abduction and maximum external rotation).^5,6

Whereas partial-thickness articular-sided RCTs have been described in overhead athletes with rotator cuff pathology, full-thickness tears are encountered less often.^7,8 Accordingly, there is a paucity of literature on clinical outcomes in professional baseball players with these injuries. To our knowledge, only 2 studies have investigated functional outcomes of open surgical repair of full-thickness tears in this population, and the outcomes have been uniformly poor.^8,9

An anatomical description of rotator cuff anatomy has demonstrated a consistent pattern of supraspinatus and infraspinatus tendon insertion relative to the articular surface, biceps groove, and the bare area of the humerus.¹⁰ Using gross and microscopic analyses, the authors noted that the supraspinatus tendon inserted immediately adjacent to the articular margin, and the infraspinatus and teres minor tapered laterally away from the margin to form the bare area. Detailed knowledge of the insertional anatomy of the rotator cuff is important, as surgical repair should recreate the broad footprint to restore normal biomechanics and increase the surface area available for healing.^11,12 Medial advancement of the rotator cuff insertion during surgical repair can have deleterious biomechanical effects on glenohumeral motion.¹¹

Given the unfavorable results found after routine open repair of full-thickness tears, we altered our approach to these injuries and adopted an arthroscopic technique in which the tendon is repaired immediately lateral to the anatomical footprint. Research studies have demonstrated that chronic stress from repetitive throwing can lead to attenuation of soft-tissue restraints, and we think preservation of these adaptive changes after surgical repair may be important for these athletes to maintain extraordinary glenohumeral rotation and achieve high throwing velocities.¹³ We conducted a study to describe the lateralized repair technique for full-thickness RCTs and to report functional outcomes in Major League Baseball (MLB) pitchers treated with this procedure at minimum 2-year follow-up. We hypothesized that use of this novel technique would result in a higher rate of return to preinjury level of play in comparison with open rotator cuff repair in comparable cohorts, as reported in other studies.^8,9

Materials and Methods

After obtaining Institutional Review Board approval for this study, we performed a retrospective chart review of MLB players treated by Dr. Altchek. We identified all professional baseball players who received a diagnosis of full-thickness RCT after preoperative magnetic resonance imaging with subsequent confirmation during surgery. Any patient who underwent arthroscopic repair using the lateralized footprint technique was included in the study. Demographic and preoperative injury information was collected from the chart, and final follow-up data were collected at the last available clinic visit. From available team records, we also obtained return-to-play data and objective pitching statistics: seasons played, games played, innings pitched, strikeouts per 9 innings, walks per 9 innings, and earned run average.

Surgical Technique

We routinely perform arthroscopic rotator cuff repairs with the patient under regional anesthesia in the beach-chair position. The operative extremity is placed in a Spider Limb Positioner (Smith & Nephew) to facilitate easy manipulation of the arm throughout the procedure. A standard posterior portal is established, and then an anterior portal is placed in the superolateral aspect of the rotator interval directly anterior to the leading edge of the supraspinatus tendon. A lateral portal created 2 to 3 cm distal to the anterolateral margin of the acromion may be used as an additional working portal. A thorough diagnostic arthroscopy is performed to evaluate the glenohumeral joint for any concomitant intra-articular pathology. Particular attention is directed to inspection of the superior labrum, biceps tendon, and capsuloligamentous structures, as injuries to these structures are often associated with rotator cuff pathology in overhead athletes.

Once presence of an RCT is confirmed, a thorough subacromial bursectomy is performed to help with visualization and inspection of the injury. The tissue is provisionally grasped and mobilized to measure the amount of available tendon excursion. In this unique population, the vast majority of injuries are diagnosed in an expeditious manner, thereby precluding the presence of significant retraction, poor tissue quality, and inadequate mobilization of the tendons. The greater tuberosity is identified, and the area immediately adjacent to the articular margin is abraded with a mechanical shaver to enhance healing potential. For supraspinatus tears, an anchor is placed immediately lateral to the articular margin in the region of the anterior attachment of the rotator cable (Figure 1). The posterior anchor is placed about 10 to 15 mm lateral to the articular margin to reattach the infraspinatus tendon (Figure 2). When the medial row sutures are tied down, anatomical placement of these anchors effectively re-creates the bare area described by Curtis and colleagues¹⁰ (Figure 3). In most cases, the medial row sutures are left intact and fixed laterally with a knotless anchor to provide a transosseous equivalent (double-row) repair.

 

 

 

Results

We identified 6 MLB pitchers who underwent arthroscopic rotator cuff repair using the aforementioned technique over an 8-year period. Each patient presented with complaints of debilitating shoulder pain and decreased pitching performance, including loss of throwing accuracy and velocity. There were 4 right-hand–dominant pitchers and 2 left-hand–dominant pitchers; rotator cuff pathology was observed in the dominant pitching arm in each case. Three players were classified as starting pitchers; the other 3 pitched in a relief role. Mean age of all pitchers at time of surgery was 29.8 years (range, 25-37 years). According to records, 2 patients (33%) underwent previous rotator cuff débridement for partial-thickness RCTs before surgical intervention at our institution. Operative information on the depth of the partial-thickness tears observed during the previous procedures was not available for review. At time of rotator cuff repair, 3 patients (50%) underwent concomitant procedures, including superior labrum anterior-posterior (SLAP) lesion repair (1 patient) and posterior labrum débridement (2 patients). A double-row fixation construct was achieved in each case. Review of operative records revealed a mean tear size of 2.1 cm (range, 1.5-3.0 cm) measured anterior to posterior, and all tears involved the supraspinatus and/or infraspinatus tendons. Postoperative rehabilitation included immobilization in a sling for 4 weeks. Hand, wrist, and elbow range-of-motion (ROM) exercises were started immediately to help reduce inflammation. Passive ROM exercises in the plane of the scapula were begun 4 weeks after surgery. Isometric scapular stabilization exercises were also incorporated at that time. Active-assisted ROM exercises were started at about 6 weeks, and isometric strengthening exercises were started at week 8 with progression to eccentric strengthening and weight training at about 3 months. Most pitchers were allowed to begin an interval throwing program at 24 weeks. There were no significant differences in the therapy programs for pitchers who underwent concomitant labral procedures, but the patient who underwent SLAP repair was limited to 30° of external rotation and 90° of forward flexion, with avoidance of active biceps contractions, for the first 6 weeks of rehabilitation.

By mean follow-up of 66.7 months (range, 23.2-94.6 months), 5 pitchers (83%) returned to their preinjury level of competition for at least 1 full season. One player pitched at Minor League Class AA level for about 1 season but was forced to retire because of persistent symptoms related to the shoulder. This pitcher underwent simultaneous rotator cuff and SLAP lesion repair. Of the 5 pitchers who resumed MLB play, none returned to their preoperative pitching productivity; mean number of innings pitched decreased from 1806.5 to 183.7. Three (60%) of these 5 pitchers experienced a slight reduction in performance as measured by earned run average. Interestingly, both players over age 30 years at time of surgery, versus 3 of the 4 pitchers under age 30 years, returned to their preoperative level of competition for at least 1 season. The Table summarizes MLB player data and objective pitching statistics. There were no perioperative complications related to this arthroscopic technique, and there were no glenohumeral ROM deficits at final follow-up.

Discussion

Although the incidence of full-thickness RCTs in professional baseball players is presumably low, available studies suggest that it is a debilitating injury with a poor prognosis for return to high-level athletics. Mazoué and Andrews⁹ reviewed the outcomes of 16 professional baseball players (12 pitchers, 4 position players) who underwent mini-open repair of full-thickness RCTs that involved more than 90% of the rotator cuff. Fifteen patients underwent mini-open rotator cuff repair using suture anchors in the anatomical footprint along with bone tunnels established near the lateral margin of the greater tuberosity to create a 2-level anatomical repair. One patient was treated with a mini-open repair using suture anchors in the greater tuberosity with a side-side repair of a longitudinal split within the rotator cuff. In the evaluation of outcomes by player position, only 1 pitcher (8%) returned to a competitive level of pitching at a mean follow-up of 67 months. On review of 2 position players with a full-thickness RCT in the dominant shoulder, only 1 (50%) returned to Major League play at a mean follow-up of 62.5 months. The remaining 2 position players underwent surgical repair of the nondominant shoulder, and, not surprisingly, both returned to their previous level of athletic activity without any difficulty. These results should be examined carefully, as the associated pathology in this high-demand cohort should not be discounted. Eleven (almost 92%) of the 12 pitchers had undergone at least 1 previous procedure on the shoulder. Furthermore, at time of full-thickness rotator cuff repair, 9 (75%) of the 12 pitchers were treated for concomitant intra-articular pathology, including SLAP tears, capsular attenuation, and/or labral fraying. In our study, 50% of pitchers underwent an associated labral procedure. Although labral débridement did not have a significant effect on return to play, the 1 pitcher who underwent SLAP repair was not able to return to preinjury level of play.

 

Tibone and colleagues⁸ reviewed postoperative outcomes in 45 athletes with rotator cuff pathology. Within their series, 5 professional baseball pitchers with full-thickness tears were treated with open subacromial decompression and rotator cuff repair. Two baseball pitchers with RCTs larger than 2 cm underwent open transosseous footprint repair in which the cuff was reinserted using bone tunnels created within the greater tuberosity. At long-term follow-up, only 2 (40%) of the 5 pitchers returned to competitive pitching. Interestingly, both pitchers who underwent transosseous footprint fixation were unable to return to professional baseball.

Overhead athletes require a delicate balance of shoulder mobility and stability to meet the high functional demands of their sports. Significant debate continues as to whether innate alterations in glenohumeral mobility preselect individuals for overhead sports, or if these changes are acquired through adaptations in supporting soft-tissue and osseous structures. Sethi and colleagues¹⁴ used an instrumented manual laxity examination to compare anterior-posterior laxity in asymptomatic professional and Division I college baseball players. The authors noted asymmetric anterior-posterior translation (>3 mm) between the throwing shoulder and the nondominant shoulder in 12 (60%) of 20 professional pitchers and 10 (59%) of 17 college pitchers. Although the authors did not correlate translational differences with corresponding shoulder pathology, the observed asymmetry supported the idea that these athletes may experience adaptive glenohumeral changes with repetitive throwing. The association between adaptive changes and shoulder biomechanics has been studied. Burkhart and Lo¹⁵ used a cadaveric model to describe the cam effect of the proximal humerus and the biomechanical consequences of a relative reduction in this effect after pathologic changes within the glenohumeral joint (constriction of posteroinferior capsule). They noted that a posterosuperior shift in the glenohumeral contact point in the throwing position can result in anterior capsular redundancy that may contribute to microinstability of the shoulder. This relative laxity increases external rotation, resulting in increased torsional and shear forces at the rotator cuff insertion.¹⁶ Ultimately, these abnormal forces may predispose overhead athletes to rotator cuff injury.

Given the available literature, it is clear that full-thickness RCTs are potentially career-ending injuries for professional baseball players. The question arises as to why the results are so poor. Ultimately, the high incidence of concomitant intra-articular pathology associated with full-thickness RCTs underscores the severity of soft-tissue damage sustained with repetitive overhead throwing. Mazoué and Andrews⁹ proposed the presence of associated labral and capsular pathology as a potential explanation for poor outcomes of surgical repair. Given the myriad of additional pathology observed in each patient, it is difficult to ascertain the precise impact of these injuries on postoperative outcome. However, early diagnosis and aggressive surgical intervention are clearly necessary to prevent accumulative injury. Regarding surgical intervention, both Tibone and colleagues⁸ and Mazoué and Andrews⁹ reported use of an open surgical repair technique in which the tendon was repaired to the anatomical footprint. Certainly, the benefits of an all-arthroscopic technique include optimal visualization of the RCT, less perioperative morbidity, and minimal soft-tissue injury. With our arthroscopic technique, the rotator cuff was fixed immediately lateral to the anatomical footprint, thereby leaving the medial aspect of the footprint uncovered. Functionally, the goal of this procedure is to restore the integrity of the rotator cuff without compromising glenohumeral mobility acquired through soft-tissue adaptation. Investigation of the insertional anatomy of the rotator cuff has demonstrated that the supraspinatus tendon inserts about 0.9 mm from the edge of the articular surface, and the infraspinatus insertional footprint tapers away from the articular surface to form the bare area as it extends inferiorly on the greater tuberosity.¹⁰ We think preexisting adaptations in glenohumeral anatomy are important for peak performance in this unique population, and even small alterations in the repair location can have deleterious effects on throwing mechanics. Lateralized repair of the cuff precludes potential medialization of the cuff insertion and may facilitate preservation of soft-tissue adaptations that these athletes rely on to achieve extraordinary glenohumeral motion.

Interestingly, with this technique we noted a higher rate of return to MLB play in pitchers over age 30 years. Although several individual factors (eg, player talent level, work ethics, compliance with rehabilitation) may play a role in this finding, it is possible that older, more mature patients may be more willing to assume diminished roles to continue to play. Jones and colleagues¹⁷ recently reported similar findings in older MLB pitchers after revision ulnar collateral ligament reconstruction.

This study had several limitations. First, the patient cohort was small (a result of the nature and relatively infrequent incidence of the clinical problem). Second, clinical information was collected retrospectively, which limited our ability to determine precise differences between preoperative and postoperative glenohumeral ROM with this technique. Third, the cohort included patients who demonstrated additional intra-articular (labral) pathology. Although associated pathology is common in this high-demand athletic population, it is clear that advanced pathology (eg, SLAP tears) may affect clinical outcomes, as in our study. Despite these limitations, our study is the largest review of professional baseball players treated for full-thickness rotator cuff injuries with an arthroscopic technique. Overall, the results of this study are promising and call for further clinical and biomechanical evaluation.

 

Conclusion

Surgical management of rotator cuff injuries in professional baseball players remains an extremely difficult problem. Current studies of full-thickness RCTs highlight these athletes’ poor functional outcomes. These unfavorable results prompted us to alter our surgical technique. Initial outcomes have been encouraging, and extended follow-up in this cohort of patients will provide a more definitive assessment of the success of this technique.

Rotator cuff injuries can be a source of debilitating pain and dysfunction in athletes at all levels, occasionally precluding return to competitive sport. Overhead athletes place extraordinary physiologic demands on the shoulder, as humeral angular velocities of 7000° to 8000° per second and rotational torques higher than 70 Nm have been measured during the baseball pitch.¹ Repetitive supraphysiologic loading of the rotator cuff throughout the coordinated phases of throwing can result in a characteristic spectrum of shoulder pathology in overhead throwers. Several studies have demonstrated partial-thickness articular-sided rotator cuff tears (RCTs) in the area of the posterior supraspinatus and anterior infraspinatus tendons.^2-4 Although the precise mechanism remains unclear, plausible explanations for the pathogenesis of these injuries include eccentric tensile and shear forces that lead to tendon failure with repetitive throwing, as well as internal impingement (mechanical impingement of the aforementioned tendons against the posterosuperior glenoid at 90° of shoulder abduction and maximum external rotation).^5,6

Whereas partial-thickness articular-sided RCTs have been described in overhead athletes with rotator cuff pathology, full-thickness tears are encountered less often.^7,8 Accordingly, there is a paucity of literature on clinical outcomes in professional baseball players with these injuries. To our knowledge, only 2 studies have investigated functional outcomes of open surgical repair of full-thickness tears in this population, and the outcomes have been uniformly poor.^8,9

An anatomical description of rotator cuff anatomy has demonstrated a consistent pattern of supraspinatus and infraspinatus tendon insertion relative to the articular surface, biceps groove, and the bare area of the humerus.¹⁰ Using gross and microscopic analyses, the authors noted that the supraspinatus tendon inserted immediately adjacent to the articular margin, and the infraspinatus and teres minor tapered laterally away from the margin to form the bare area. Detailed knowledge of the insertional anatomy of the rotator cuff is important, as surgical repair should recreate the broad footprint to restore normal biomechanics and increase the surface area available for healing.^11,12 Medial advancement of the rotator cuff insertion during surgical repair can have deleterious biomechanical effects on glenohumeral motion.¹¹

Given the unfavorable results found after routine open repair of full-thickness tears, we altered our approach to these injuries and adopted an arthroscopic technique in which the tendon is repaired immediately lateral to the anatomical footprint. Research studies have demonstrated that chronic stress from repetitive throwing can lead to attenuation of soft-tissue restraints, and we think preservation of these adaptive changes after surgical repair may be important for these athletes to maintain extraordinary glenohumeral rotation and achieve high throwing velocities.¹³ We conducted a study to describe the lateralized repair technique for full-thickness RCTs and to report functional outcomes in Major League Baseball (MLB) pitchers treated with this procedure at minimum 2-year follow-up. We hypothesized that use of this novel technique would result in a higher rate of return to preinjury level of play in comparison with open rotator cuff repair in comparable cohorts, as reported in other studies.^8,9

Materials and Methods

After obtaining Institutional Review Board approval for this study, we performed a retrospective chart review of MLB players treated by Dr. Altchek. We identified all professional baseball players who received a diagnosis of full-thickness RCT after preoperative magnetic resonance imaging with subsequent confirmation during surgery. Any patient who underwent arthroscopic repair using the lateralized footprint technique was included in the study. Demographic and preoperative injury information was collected from the chart, and final follow-up data were collected at the last available clinic visit. From available team records, we also obtained return-to-play data and objective pitching statistics: seasons played, games played, innings pitched, strikeouts per 9 innings, walks per 9 innings, and earned run average.

Surgical Technique

We routinely perform arthroscopic rotator cuff repairs with the patient under regional anesthesia in the beach-chair position. The operative extremity is placed in a Spider Limb Positioner (Smith & Nephew) to facilitate easy manipulation of the arm throughout the procedure. A standard posterior portal is established, and then an anterior portal is placed in the superolateral aspect of the rotator interval directly anterior to the leading edge of the supraspinatus tendon. A lateral portal created 2 to 3 cm distal to the anterolateral margin of the acromion may be used as an additional working portal. A thorough diagnostic arthroscopy is performed to evaluate the glenohumeral joint for any concomitant intra-articular pathology. Particular attention is directed to inspection of the superior labrum, biceps tendon, and capsuloligamentous structures, as injuries to these structures are often associated with rotator cuff pathology in overhead athletes.

Once presence of an RCT is confirmed, a thorough subacromial bursectomy is performed to help with visualization and inspection of the injury. The tissue is provisionally grasped and mobilized to measure the amount of available tendon excursion. In this unique population, the vast majority of injuries are diagnosed in an expeditious manner, thereby precluding the presence of significant retraction, poor tissue quality, and inadequate mobilization of the tendons. The greater tuberosity is identified, and the area immediately adjacent to the articular margin is abraded with a mechanical shaver to enhance healing potential. For supraspinatus tears, an anchor is placed immediately lateral to the articular margin in the region of the anterior attachment of the rotator cable (Figure 1). The posterior anchor is placed about 10 to 15 mm lateral to the articular margin to reattach the infraspinatus tendon (Figure 2). When the medial row sutures are tied down, anatomical placement of these anchors effectively re-creates the bare area described by Curtis and colleagues¹⁰ (Figure 3). In most cases, the medial row sutures are left intact and fixed laterally with a knotless anchor to provide a transosseous equivalent (double-row) repair.

 

 

 

Results

We identified 6 MLB pitchers who underwent arthroscopic rotator cuff repair using the aforementioned technique over an 8-year period. Each patient presented with complaints of debilitating shoulder pain and decreased pitching performance, including loss of throwing accuracy and velocity. There were 4 right-hand–dominant pitchers and 2 left-hand–dominant pitchers; rotator cuff pathology was observed in the dominant pitching arm in each case. Three players were classified as starting pitchers; the other 3 pitched in a relief role. Mean age of all pitchers at time of surgery was 29.8 years (range, 25-37 years). According to records, 2 patients (33%) underwent previous rotator cuff débridement for partial-thickness RCTs before surgical intervention at our institution. Operative information on the depth of the partial-thickness tears observed during the previous procedures was not available for review. At time of rotator cuff repair, 3 patients (50%) underwent concomitant procedures, including superior labrum anterior-posterior (SLAP) lesion repair (1 patient) and posterior labrum débridement (2 patients). A double-row fixation construct was achieved in each case. Review of operative records revealed a mean tear size of 2.1 cm (range, 1.5-3.0 cm) measured anterior to posterior, and all tears involved the supraspinatus and/or infraspinatus tendons. Postoperative rehabilitation included immobilization in a sling for 4 weeks. Hand, wrist, and elbow range-of-motion (ROM) exercises were started immediately to help reduce inflammation. Passive ROM exercises in the plane of the scapula were begun 4 weeks after surgery. Isometric scapular stabilization exercises were also incorporated at that time. Active-assisted ROM exercises were started at about 6 weeks, and isometric strengthening exercises were started at week 8 with progression to eccentric strengthening and weight training at about 3 months. Most pitchers were allowed to begin an interval throwing program at 24 weeks. There were no significant differences in the therapy programs for pitchers who underwent concomitant labral procedures, but the patient who underwent SLAP repair was limited to 30° of external rotation and 90° of forward flexion, with avoidance of active biceps contractions, for the first 6 weeks of rehabilitation.

By mean follow-up of 66.7 months (range, 23.2-94.6 months), 5 pitchers (83%) returned to their preinjury level of competition for at least 1 full season. One player pitched at Minor League Class AA level for about 1 season but was forced to retire because of persistent symptoms related to the shoulder. This pitcher underwent simultaneous rotator cuff and SLAP lesion repair. Of the 5 pitchers who resumed MLB play, none returned to their preoperative pitching productivity; mean number of innings pitched decreased from 1806.5 to 183.7. Three (60%) of these 5 pitchers experienced a slight reduction in performance as measured by earned run average. Interestingly, both players over age 30 years at time of surgery, versus 3 of the 4 pitchers under age 30 years, returned to their preoperative level of competition for at least 1 season. The Table summarizes MLB player data and objective pitching statistics. There were no perioperative complications related to this arthroscopic technique, and there were no glenohumeral ROM deficits at final follow-up.

Discussion

Although the incidence of full-thickness RCTs in professional baseball players is presumably low, available studies suggest that it is a debilitating injury with a poor prognosis for return to high-level athletics. Mazoué and Andrews⁹ reviewed the outcomes of 16 professional baseball players (12 pitchers, 4 position players) who underwent mini-open repair of full-thickness RCTs that involved more than 90% of the rotator cuff. Fifteen patients underwent mini-open rotator cuff repair using suture anchors in the anatomical footprint along with bone tunnels established near the lateral margin of the greater tuberosity to create a 2-level anatomical repair. One patient was treated with a mini-open repair using suture anchors in the greater tuberosity with a side-side repair of a longitudinal split within the rotator cuff. In the evaluation of outcomes by player position, only 1 pitcher (8%) returned to a competitive level of pitching at a mean follow-up of 67 months. On review of 2 position players with a full-thickness RCT in the dominant shoulder, only 1 (50%) returned to Major League play at a mean follow-up of 62.5 months. The remaining 2 position players underwent surgical repair of the nondominant shoulder, and, not surprisingly, both returned to their previous level of athletic activity without any difficulty. These results should be examined carefully, as the associated pathology in this high-demand cohort should not be discounted. Eleven (almost 92%) of the 12 pitchers had undergone at least 1 previous procedure on the shoulder. Furthermore, at time of full-thickness rotator cuff repair, 9 (75%) of the 12 pitchers were treated for concomitant intra-articular pathology, including SLAP tears, capsular attenuation, and/or labral fraying. In our study, 50% of pitchers underwent an associated labral procedure. Although labral débridement did not have a significant effect on return to play, the 1 pitcher who underwent SLAP repair was not able to return to preinjury level of play.

 

Tibone and colleagues⁸ reviewed postoperative outcomes in 45 athletes with rotator cuff pathology. Within their series, 5 professional baseball pitchers with full-thickness tears were treated with open subacromial decompression and rotator cuff repair. Two baseball pitchers with RCTs larger than 2 cm underwent open transosseous footprint repair in which the cuff was reinserted using bone tunnels created within the greater tuberosity. At long-term follow-up, only 2 (40%) of the 5 pitchers returned to competitive pitching. Interestingly, both pitchers who underwent transosseous footprint fixation were unable to return to professional baseball.

Overhead athletes require a delicate balance of shoulder mobility and stability to meet the high functional demands of their sports. Significant debate continues as to whether innate alterations in glenohumeral mobility preselect individuals for overhead sports, or if these changes are acquired through adaptations in supporting soft-tissue and osseous structures. Sethi and colleagues¹⁴ used an instrumented manual laxity examination to compare anterior-posterior laxity in asymptomatic professional and Division I college baseball players. The authors noted asymmetric anterior-posterior translation (>3 mm) between the throwing shoulder and the nondominant shoulder in 12 (60%) of 20 professional pitchers and 10 (59%) of 17 college pitchers. Although the authors did not correlate translational differences with corresponding shoulder pathology, the observed asymmetry supported the idea that these athletes may experience adaptive glenohumeral changes with repetitive throwing. The association between adaptive changes and shoulder biomechanics has been studied. Burkhart and Lo¹⁵ used a cadaveric model to describe the cam effect of the proximal humerus and the biomechanical consequences of a relative reduction in this effect after pathologic changes within the glenohumeral joint (constriction of posteroinferior capsule). They noted that a posterosuperior shift in the glenohumeral contact point in the throwing position can result in anterior capsular redundancy that may contribute to microinstability of the shoulder. This relative laxity increases external rotation, resulting in increased torsional and shear forces at the rotator cuff insertion.¹⁶ Ultimately, these abnormal forces may predispose overhead athletes to rotator cuff injury.

Given the available literature, it is clear that full-thickness RCTs are potentially career-ending injuries for professional baseball players. The question arises as to why the results are so poor. Ultimately, the high incidence of concomitant intra-articular pathology associated with full-thickness RCTs underscores the severity of soft-tissue damage sustained with repetitive overhead throwing. Mazoué and Andrews⁹ proposed the presence of associated labral and capsular pathology as a potential explanation for poor outcomes of surgical repair. Given the myriad of additional pathology observed in each patient, it is difficult to ascertain the precise impact of these injuries on postoperative outcome. However, early diagnosis and aggressive surgical intervention are clearly necessary to prevent accumulative injury. Regarding surgical intervention, both Tibone and colleagues⁸ and Mazoué and Andrews⁹ reported use of an open surgical repair technique in which the tendon was repaired to the anatomical footprint. Certainly, the benefits of an all-arthroscopic technique include optimal visualization of the RCT, less perioperative morbidity, and minimal soft-tissue injury. With our arthroscopic technique, the rotator cuff was fixed immediately lateral to the anatomical footprint, thereby leaving the medial aspect of the footprint uncovered. Functionally, the goal of this procedure is to restore the integrity of the rotator cuff without compromising glenohumeral mobility acquired through soft-tissue adaptation. Investigation of the insertional anatomy of the rotator cuff has demonstrated that the supraspinatus tendon inserts about 0.9 mm from the edge of the articular surface, and the infraspinatus insertional footprint tapers away from the articular surface to form the bare area as it extends inferiorly on the greater tuberosity.¹⁰ We think preexisting adaptations in glenohumeral anatomy are important for peak performance in this unique population, and even small alterations in the repair location can have deleterious effects on throwing mechanics. Lateralized repair of the cuff precludes potential medialization of the cuff insertion and may facilitate preservation of soft-tissue adaptations that these athletes rely on to achieve extraordinary glenohumeral motion.

Interestingly, with this technique we noted a higher rate of return to MLB play in pitchers over age 30 years. Although several individual factors (eg, player talent level, work ethics, compliance with rehabilitation) may play a role in this finding, it is possible that older, more mature patients may be more willing to assume diminished roles to continue to play. Jones and colleagues¹⁷ recently reported similar findings in older MLB pitchers after revision ulnar collateral ligament reconstruction.

This study had several limitations. First, the patient cohort was small (a result of the nature and relatively infrequent incidence of the clinical problem). Second, clinical information was collected retrospectively, which limited our ability to determine precise differences between preoperative and postoperative glenohumeral ROM with this technique. Third, the cohort included patients who demonstrated additional intra-articular (labral) pathology. Although associated pathology is common in this high-demand athletic population, it is clear that advanced pathology (eg, SLAP tears) may affect clinical outcomes, as in our study. Despite these limitations, our study is the largest review of professional baseball players treated for full-thickness rotator cuff injuries with an arthroscopic technique. Overall, the results of this study are promising and call for further clinical and biomechanical evaluation.

 

Conclusion

Surgical management of rotator cuff injuries in professional baseball players remains an extremely difficult problem. Current studies of full-thickness RCTs highlight these athletes’ poor functional outcomes. These unfavorable results prompted us to alter our surgical technique. Initial outcomes have been encouraging, and extended follow-up in this cohort of patients will provide a more definitive assessment of the success of this technique.

Repair of the ulnar collateral ligament (UCL) was first reported by Norwood and colleagues¹ in a group of athletes who sustained acute UCL ruptures. Of the 4 athletes in their cohort who underwent direct UCL repair, none were noted to have any residual instability 2 years after the surgery. However, none of these 4 were overhead throwing athletes. Jobe and colleagues² first published Jobe’s technique of UCL reconstruction in 1986, but it was Conway and colleagus’³ 1992 publication describing Jobe’s experience with UCL injury and surgical treatment in throwing athletes that set the early standard for management in that population. Since those landmark studies, there has been a tremendous increase in attention to this near-epidemic clinical problem.

Although these studies were the first to describe the surgical procedure that is now often referred to as “Tommy John surgery,” named after Jobe’s initial patient in 1974, Conway and colleagues³ also reported on Jobe’s early experience with UCL repair. In fact, of the 70 patients reported in the Conway and colleagues’³ article, 14 were treated with repair of the ligament. Only 7 of the 14 (50%) of those who underwent UCL repair were able to return to the same level of play, and only 2 of the 7 (29%) of Major League Baseball (MLB) players who underwent UCL repair were able to return to competition at the MLB level. This compared very poorly with the nearly 75% rate of return to competition in patients who underwent UCL reconstructions in the same cohort. In Azar and colleagues’⁴ 2000 report on Dr. James Andrews’ experience with UCL injury and treatment in male college and professional baseball players, UCL repair again did poorly when compared to UCL reconstruction, with only 5 of the 8 (63%) of UCL repair patients returning to the same level of play compared to 41 of the 51 (81%) of UCL reconstructions using a modification of Jobe’s original technique.

Since the mid-1990s, numerous new techniques have been described and shown to have acceptable and largely successful outcomes in treating UCL injuries.^5-9 All of them involve placing or anchoring a spanning piece of tendon graft from the native origin on the medial epicondyle of the humerus to the native insertion on the sublime tubercle of the ulna. These palpable and visible anatomic landmarks are important to the UCL surgeon due to the need to place the graft or repair the torn ligament tissue to its normal anatomic origin and/or insertion.¹⁰ Regardless of whether the graft is sewn, docked, tunneled, or anchored, these types of procedures have demonstrated rates of return to competition at the same or higher level of play in the 75% to 92% range.^3,4,7,11-13 In the largest published series of 1281 UCL reconstructions by Cain and colleagues⁷ at American Sports Medicine Institute (Birmingham, AL), the rate of return to play at the same or higher level was 84%, with the average time to return to play of 11.4 months. On the basis of these robust clinical studies and numerous basic science studies demonstrating essentially equivalent strength and function among reconstruction techniques, UCL reconstruction now enjoys an acceptance among clinicians, athletes, athletic trainers, coaches, and team management at all levels of overhead sports.

In comparison to UCL reconstruction, relatively little has been published on UCL repair since 2000. Certainly this is in part due to the success of its clinical descendant. UCL repair did not appear on the pages of peer-reviewed literature until 2006, when Argo and colleagues¹¹ published a report on the outcome of 17 UCL repairs in female athletes using a variety of techniques, including plication, anchor-to-bone, and drill holes. Although there was only 1 pitcher in the group, 16 of the 17 (94%) returned to the same or higher level of competition at an average of only 3 months after surgery.¹¹

Savoie and colleagues¹³ followed this in 2008 with a report on 60 UCL repairs in overhead athletes. Of the 51 patients in this study in which the ligament was repaired to bone using suture anchors, 93% returned to the same or higher level of play at an average of only 6 months after surgery. Including Jobe’s original group, there have been less than 100 patients ever reported to have had a UCL repair performed. In comparison to the thousands of UCL reconstructions that have been reported over the last 20 years, it is not surprising that UCL repair has not gained great popularity among surgeons and patients. It is also important to remember that suture and anchor technology has come a long way since the 1970s, and our overall knowledge of the injury and its treatments and rehabilitation have grown tremendously since that time.

 

A New Technique for UCL Repair

Since we began data collection in Birmingham, Alabama in the mid 1990s, our practice has successfully treated thousands of overhead athletes of all types with the modified Jobe technique of UCL reconstruction, using either a palmaris longus tendon or a gracilis tendon graft.⁷ Until August 2013, this technique was exclusively utilized regardless of the amount and location of pathology encountered at the time of surgery. The range of pathology, from partial undersurface tearing to complete disruption of the ligament tissue, was treated by placing a graft at the anatomic insertion points of the native ligament. While the success of this experience cannot be overlooked, we also realized that we were treating a broad spectrum of pathology and injury with the same operation.

Recognizing the valuable contributions of earlier authors who had attempted UCL repair previously, we asked whether we were doing too much of an operation for all of the various pathology we saw at the time of surgery, and whether the availability of modern anchor and suture technology, vast clinical experience with these injuries and their outcomes, and even biologic additives could be applied to some of these patients in order to achieve an equal or superior outcome in less time. In particular, could such a technique be applied to the ever-increasing number of younger athletes with less pathology, who more frequently suffer end-avulsions and partial tears of their UCL?

These thoughts, along with Savoie and colleagues’¹³ experience with UCL repair using suture anchors, led us to create a construct that could be used to not only repair the torn native UCL tissue to bone, but also span the anatomic native ligament from its origin to its insertion. The construct includes an ultra-strong collagen coated tape (FiberTape, Arthrex) attached at the anatomic insertions of the ligament using two 3.5-mm nonabsorbable PEEK corkscrew anchors (SwiveLock, Arthrex), and a suture through the eyelet of one of the anchors (Figure 1). Using this construct, the native ligament disruption can be repaired directly to bone using the suture through the eyelet of the anchor, and the remainder of the native ligament is augmented with the spanning biologic enhanced tape (Figures 2A-2C). The construct is created by placing one end of the tape through the eyelet of the first anchor, and then placing one end of a No. zero braided permanent suture through the same eyelet. Both ends of the tape are then placed through the eyelet of the second anchor. The first anchor is inserted into a hole drilled at the apex of the insertion of the torn end of the native ligament. This anchor is placed first in order to allow for direct repair of the native torn ligament using the free suture through the eyelet of the first anchor. The second hole is then drilled at the insertion of the native ligament on the uninjured end of the native ligament. In order to accommodate the volume of tape in the hole created for the second anchor, a slightly oversized drill and tap were created specifically for this technique (Arthrex).

 

Before attempting this in vivo, a cadaveric study was carried out in order to ensure that the time-zero function of the construct would be at least as good as the standard UCL reconstruction technique we have used for several decades.¹⁴ The time-zero gap formation under valgus load was less for the repair/augmentation than for the standard reconstruction with palmaris longus, and the ultimate failure strength of the repair was the same as in the reconstruction group, with all failures through bone in the cadaveric specimens. No anchors pulled out of bone, and the tape did not tear in any specimen.

This basic science study has given us confidence to proceed with the use of this technique in patients. The first patient was treated with this construct in August 2013. The outcomes of our first series of patients were presented on Saturday, March 5 at American Orthopaedic Society for Sports Medicine Specialty Day during the 2016 American Academy of Orthopaedic Surgeons annual meeting in Orlando, FL.

We do not feel that this technique is adequate for the treatment of the UCL that has sustained attritional injury and contains poor quality native ligament tissue. Before we do these procedures, we always discuss with the patient the possibility that full reconstruction may be required, and that the decision to proceed with UCL repair is contingent upon the quality and quantity of the native UCL tissue present at the time of surgery. If the quality of the native tissue is poor (chronic degenerative changes, etc), full reconstruction with autograft tendon is recommended. It is our hope that this technique will afford the UCL surgeon another option for treating end-avulsions and partial thickness injuries, with a more rapid and successful return to normal function and competition.

Repair of the ulnar collateral ligament (UCL) was first reported by Norwood and colleagues¹ in a group of athletes who sustained acute UCL ruptures. Of the 4 athletes in their cohort who underwent direct UCL repair, none were noted to have any residual instability 2 years after the surgery. However, none of these 4 were overhead throwing athletes. Jobe and colleagues² first published Jobe’s technique of UCL reconstruction in 1986, but it was Conway and colleagus’³ 1992 publication describing Jobe’s experience with UCL injury and surgical treatment in throwing athletes that set the early standard for management in that population. Since those landmark studies, there has been a tremendous increase in attention to this near-epidemic clinical problem.

Although these studies were the first to describe the surgical procedure that is now often referred to as “Tommy John surgery,” named after Jobe’s initial patient in 1974, Conway and colleagues³ also reported on Jobe’s early experience with UCL repair. In fact, of the 70 patients reported in the Conway and colleagues’³ article, 14 were treated with repair of the ligament. Only 7 of the 14 (50%) of those who underwent UCL repair were able to return to the same level of play, and only 2 of the 7 (29%) of Major League Baseball (MLB) players who underwent UCL repair were able to return to competition at the MLB level. This compared very poorly with the nearly 75% rate of return to competition in patients who underwent UCL reconstructions in the same cohort. In Azar and colleagues’⁴ 2000 report on Dr. James Andrews’ experience with UCL injury and treatment in male college and professional baseball players, UCL repair again did poorly when compared to UCL reconstruction, with only 5 of the 8 (63%) of UCL repair patients returning to the same level of play compared to 41 of the 51 (81%) of UCL reconstructions using a modification of Jobe’s original technique.

Since the mid-1990s, numerous new techniques have been described and shown to have acceptable and largely successful outcomes in treating UCL injuries.^5-9 All of them involve placing or anchoring a spanning piece of tendon graft from the native origin on the medial epicondyle of the humerus to the native insertion on the sublime tubercle of the ulna. These palpable and visible anatomic landmarks are important to the UCL surgeon due to the need to place the graft or repair the torn ligament tissue to its normal anatomic origin and/or insertion.¹⁰ Regardless of whether the graft is sewn, docked, tunneled, or anchored, these types of procedures have demonstrated rates of return to competition at the same or higher level of play in the 75% to 92% range.^3,4,7,11-13 In the largest published series of 1281 UCL reconstructions by Cain and colleagues⁷ at American Sports Medicine Institute (Birmingham, AL), the rate of return to play at the same or higher level was 84%, with the average time to return to play of 11.4 months. On the basis of these robust clinical studies and numerous basic science studies demonstrating essentially equivalent strength and function among reconstruction techniques, UCL reconstruction now enjoys an acceptance among clinicians, athletes, athletic trainers, coaches, and team management at all levels of overhead sports.

In comparison to UCL reconstruction, relatively little has been published on UCL repair since 2000. Certainly this is in part due to the success of its clinical descendant. UCL repair did not appear on the pages of peer-reviewed literature until 2006, when Argo and colleagues¹¹ published a report on the outcome of 17 UCL repairs in female athletes using a variety of techniques, including plication, anchor-to-bone, and drill holes. Although there was only 1 pitcher in the group, 16 of the 17 (94%) returned to the same or higher level of competition at an average of only 3 months after surgery.¹¹

Savoie and colleagues¹³ followed this in 2008 with a report on 60 UCL repairs in overhead athletes. Of the 51 patients in this study in which the ligament was repaired to bone using suture anchors, 93% returned to the same or higher level of play at an average of only 6 months after surgery. Including Jobe’s original group, there have been less than 100 patients ever reported to have had a UCL repair performed. In comparison to the thousands of UCL reconstructions that have been reported over the last 20 years, it is not surprising that UCL repair has not gained great popularity among surgeons and patients. It is also important to remember that suture and anchor technology has come a long way since the 1970s, and our overall knowledge of the injury and its treatments and rehabilitation have grown tremendously since that time.

 

A New Technique for UCL Repair

Since we began data collection in Birmingham, Alabama in the mid 1990s, our practice has successfully treated thousands of overhead athletes of all types with the modified Jobe technique of UCL reconstruction, using either a palmaris longus tendon or a gracilis tendon graft.⁷ Until August 2013, this technique was exclusively utilized regardless of the amount and location of pathology encountered at the time of surgery. The range of pathology, from partial undersurface tearing to complete disruption of the ligament tissue, was treated by placing a graft at the anatomic insertion points of the native ligament. While the success of this experience cannot be overlooked, we also realized that we were treating a broad spectrum of pathology and injury with the same operation.

Recognizing the valuable contributions of earlier authors who had attempted UCL repair previously, we asked whether we were doing too much of an operation for all of the various pathology we saw at the time of surgery, and whether the availability of modern anchor and suture technology, vast clinical experience with these injuries and their outcomes, and even biologic additives could be applied to some of these patients in order to achieve an equal or superior outcome in less time. In particular, could such a technique be applied to the ever-increasing number of younger athletes with less pathology, who more frequently suffer end-avulsions and partial tears of their UCL?

These thoughts, along with Savoie and colleagues’¹³ experience with UCL repair using suture anchors, led us to create a construct that could be used to not only repair the torn native UCL tissue to bone, but also span the anatomic native ligament from its origin to its insertion. The construct includes an ultra-strong collagen coated tape (FiberTape, Arthrex) attached at the anatomic insertions of the ligament using two 3.5-mm nonabsorbable PEEK corkscrew anchors (SwiveLock, Arthrex), and a suture through the eyelet of one of the anchors (Figure 1). Using this construct, the native ligament disruption can be repaired directly to bone using the suture through the eyelet of the anchor, and the remainder of the native ligament is augmented with the spanning biologic enhanced tape (Figures 2A-2C). The construct is created by placing one end of the tape through the eyelet of the first anchor, and then placing one end of a No. zero braided permanent suture through the same eyelet. Both ends of the tape are then placed through the eyelet of the second anchor. The first anchor is inserted into a hole drilled at the apex of the insertion of the torn end of the native ligament. This anchor is placed first in order to allow for direct repair of the native torn ligament using the free suture through the eyelet of the first anchor. The second hole is then drilled at the insertion of the native ligament on the uninjured end of the native ligament. In order to accommodate the volume of tape in the hole created for the second anchor, a slightly oversized drill and tap were created specifically for this technique (Arthrex).

 

Before attempting this in vivo, a cadaveric study was carried out in order to ensure that the time-zero function of the construct would be at least as good as the standard UCL reconstruction technique we have used for several decades.¹⁴ The time-zero gap formation under valgus load was less for the repair/augmentation than for the standard reconstruction with palmaris longus, and the ultimate failure strength of the repair was the same as in the reconstruction group, with all failures through bone in the cadaveric specimens. No anchors pulled out of bone, and the tape did not tear in any specimen.

This basic science study has given us confidence to proceed with the use of this technique in patients. The first patient was treated with this construct in August 2013. The outcomes of our first series of patients were presented on Saturday, March 5 at American Orthopaedic Society for Sports Medicine Specialty Day during the 2016 American Academy of Orthopaedic Surgeons annual meeting in Orlando, FL.

We do not feel that this technique is adequate for the treatment of the UCL that has sustained attritional injury and contains poor quality native ligament tissue. Before we do these procedures, we always discuss with the patient the possibility that full reconstruction may be required, and that the decision to proceed with UCL repair is contingent upon the quality and quantity of the native UCL tissue present at the time of surgery. If the quality of the native tissue is poor (chronic degenerative changes, etc), full reconstruction with autograft tendon is recommended. It is our hope that this technique will afford the UCL surgeon another option for treating end-avulsions and partial thickness injuries, with a more rapid and successful return to normal function and competition.

Repair of the ulnar collateral ligament (UCL) was first reported by Norwood and colleagues¹ in a group of athletes who sustained acute UCL ruptures. Of the 4 athletes in their cohort who underwent direct UCL repair, none were noted to have any residual instability 2 years after the surgery. However, none of these 4 were overhead throwing athletes. Jobe and colleagues² first published Jobe’s technique of UCL reconstruction in 1986, but it was Conway and colleagus’³ 1992 publication describing Jobe’s experience with UCL injury and surgical treatment in throwing athletes that set the early standard for management in that population. Since those landmark studies, there has been a tremendous increase in attention to this near-epidemic clinical problem.

Although these studies were the first to describe the surgical procedure that is now often referred to as “Tommy John surgery,” named after Jobe’s initial patient in 1974, Conway and colleagues³ also reported on Jobe’s early experience with UCL repair. In fact, of the 70 patients reported in the Conway and colleagues’³ article, 14 were treated with repair of the ligament. Only 7 of the 14 (50%) of those who underwent UCL repair were able to return to the same level of play, and only 2 of the 7 (29%) of Major League Baseball (MLB) players who underwent UCL repair were able to return to competition at the MLB level. This compared very poorly with the nearly 75% rate of return to competition in patients who underwent UCL reconstructions in the same cohort. In Azar and colleagues’⁴ 2000 report on Dr. James Andrews’ experience with UCL injury and treatment in male college and professional baseball players, UCL repair again did poorly when compared to UCL reconstruction, with only 5 of the 8 (63%) of UCL repair patients returning to the same level of play compared to 41 of the 51 (81%) of UCL reconstructions using a modification of Jobe’s original technique.

Since the mid-1990s, numerous new techniques have been described and shown to have acceptable and largely successful outcomes in treating UCL injuries.^5-9 All of them involve placing or anchoring a spanning piece of tendon graft from the native origin on the medial epicondyle of the humerus to the native insertion on the sublime tubercle of the ulna. These palpable and visible anatomic landmarks are important to the UCL surgeon due to the need to place the graft or repair the torn ligament tissue to its normal anatomic origin and/or insertion.¹⁰ Regardless of whether the graft is sewn, docked, tunneled, or anchored, these types of procedures have demonstrated rates of return to competition at the same or higher level of play in the 75% to 92% range.^3,4,7,11-13 In the largest published series of 1281 UCL reconstructions by Cain and colleagues⁷ at American Sports Medicine Institute (Birmingham, AL), the rate of return to play at the same or higher level was 84%, with the average time to return to play of 11.4 months. On the basis of these robust clinical studies and numerous basic science studies demonstrating essentially equivalent strength and function among reconstruction techniques, UCL reconstruction now enjoys an acceptance among clinicians, athletes, athletic trainers, coaches, and team management at all levels of overhead sports.

In comparison to UCL reconstruction, relatively little has been published on UCL repair since 2000. Certainly this is in part due to the success of its clinical descendant. UCL repair did not appear on the pages of peer-reviewed literature until 2006, when Argo and colleagues¹¹ published a report on the outcome of 17 UCL repairs in female athletes using a variety of techniques, including plication, anchor-to-bone, and drill holes. Although there was only 1 pitcher in the group, 16 of the 17 (94%) returned to the same or higher level of competition at an average of only 3 months after surgery.¹¹

Savoie and colleagues¹³ followed this in 2008 with a report on 60 UCL repairs in overhead athletes. Of the 51 patients in this study in which the ligament was repaired to bone using suture anchors, 93% returned to the same or higher level of play at an average of only 6 months after surgery. Including Jobe’s original group, there have been less than 100 patients ever reported to have had a UCL repair performed. In comparison to the thousands of UCL reconstructions that have been reported over the last 20 years, it is not surprising that UCL repair has not gained great popularity among surgeons and patients. It is also important to remember that suture and anchor technology has come a long way since the 1970s, and our overall knowledge of the injury and its treatments and rehabilitation have grown tremendously since that time.

 

A New Technique for UCL Repair

Since we began data collection in Birmingham, Alabama in the mid 1990s, our practice has successfully treated thousands of overhead athletes of all types with the modified Jobe technique of UCL reconstruction, using either a palmaris longus tendon or a gracilis tendon graft.⁷ Until August 2013, this technique was exclusively utilized regardless of the amount and location of pathology encountered at the time of surgery. The range of pathology, from partial undersurface tearing to complete disruption of the ligament tissue, was treated by placing a graft at the anatomic insertion points of the native ligament. While the success of this experience cannot be overlooked, we also realized that we were treating a broad spectrum of pathology and injury with the same operation.

Recognizing the valuable contributions of earlier authors who had attempted UCL repair previously, we asked whether we were doing too much of an operation for all of the various pathology we saw at the time of surgery, and whether the availability of modern anchor and suture technology, vast clinical experience with these injuries and their outcomes, and even biologic additives could be applied to some of these patients in order to achieve an equal or superior outcome in less time. In particular, could such a technique be applied to the ever-increasing number of younger athletes with less pathology, who more frequently suffer end-avulsions and partial tears of their UCL?

These thoughts, along with Savoie and colleagues’¹³ experience with UCL repair using suture anchors, led us to create a construct that could be used to not only repair the torn native UCL tissue to bone, but also span the anatomic native ligament from its origin to its insertion. The construct includes an ultra-strong collagen coated tape (FiberTape, Arthrex) attached at the anatomic insertions of the ligament using two 3.5-mm nonabsorbable PEEK corkscrew anchors (SwiveLock, Arthrex), and a suture through the eyelet of one of the anchors (Figure 1). Using this construct, the native ligament disruption can be repaired directly to bone using the suture through the eyelet of the anchor, and the remainder of the native ligament is augmented with the spanning biologic enhanced tape (Figures 2A-2C). The construct is created by placing one end of the tape through the eyelet of the first anchor, and then placing one end of a No. zero braided permanent suture through the same eyelet. Both ends of the tape are then placed through the eyelet of the second anchor. The first anchor is inserted into a hole drilled at the apex of the insertion of the torn end of the native ligament. This anchor is placed first in order to allow for direct repair of the native torn ligament using the free suture through the eyelet of the first anchor. The second hole is then drilled at the insertion of the native ligament on the uninjured end of the native ligament. In order to accommodate the volume of tape in the hole created for the second anchor, a slightly oversized drill and tap were created specifically for this technique (Arthrex).

 

Before attempting this in vivo, a cadaveric study was carried out in order to ensure that the time-zero function of the construct would be at least as good as the standard UCL reconstruction technique we have used for several decades.¹⁴ The time-zero gap formation under valgus load was less for the repair/augmentation than for the standard reconstruction with palmaris longus, and the ultimate failure strength of the repair was the same as in the reconstruction group, with all failures through bone in the cadaveric specimens. No anchors pulled out of bone, and the tape did not tear in any specimen.

This basic science study has given us confidence to proceed with the use of this technique in patients. The first patient was treated with this construct in August 2013. The outcomes of our first series of patients were presented on Saturday, March 5 at American Orthopaedic Society for Sports Medicine Specialty Day during the 2016 American Academy of Orthopaedic Surgeons annual meeting in Orlando, FL.

We do not feel that this technique is adequate for the treatment of the UCL that has sustained attritional injury and contains poor quality native ligament tissue. Before we do these procedures, we always discuss with the patient the possibility that full reconstruction may be required, and that the decision to proceed with UCL repair is contingent upon the quality and quantity of the native UCL tissue present at the time of surgery. If the quality of the native tissue is poor (chronic degenerative changes, etc), full reconstruction with autograft tendon is recommended. It is our hope that this technique will afford the UCL surgeon another option for treating end-avulsions and partial thickness injuries, with a more rapid and successful return to normal function and competition.

Injuries around the hip and groin occurring in professional baseball players can present as muscle strains, avulsions, contusions, hip subluxations or dislocations, femoroacetabular impingement (FAI) causing labral tears or chondral defects, and athletic pubalgia.^1-9 Several recent articles have reported on the epidemiology of musculoskeletal injuries in Major League Baseball (MLB) players^4,8,10 but with little attention to injuries to the hip and groin, likely because prior studies show only a 6.3% overall incidence for these injuries, much less than the more commonly discussed shoulder or elbow injuries.⁸ Despite the lower proportion of hip and groin injuries overall, these injuries lead to a relatively long period of disability for the players and often have a high rate of recurrence.^4,8,9

The important contribution of hip mechanics and the surrounding muscular function in the kinetic chain during overhead athletic activities, such as a tennis serve or throwing, has recently been discussed.^11,12 In sports requiring overhead activities, trunk rotation is a key component to generating force, and hip internal and external rotation is necessary for this trunk rotation to occur.^12,13 Alterations in hip morphology causing constrained motion, as seen in FAI, may predispose an overhead throwing athlete to intra-articular injury such as labral tears or chondral injuries, or to a compensatory movement pattern causing an extra-articular soft tissue injury about the hip.¹² Decreased hip range of motion may also lead to increased forces across the upper extremity during the throwing motion, which puts the shoulder and elbow at increased risk of injury.¹²

Increased awareness of hip and groin injuries, advances in diagnostic imaging, and an understanding of the relationship between the throwing motion in baseball and hip mechanics have improved our ability to appropriately identify and treat athletes with injuries of the hip and groin. Several studies on hip and groin injuries in elite athletes treated both operatively and nonoperatively have reported a high rate of return to sport.^3,7,14-19 A systematic review on return to sport following hip arthroscopy for intra-articular pathology associated with FAI showed a 95% return to sport rate and a 92% rate of return to pre-injury level of play in a subgroup of professional athletes in 9 studies.²⁰

Despite the large body of literature on upper extremity injuries, there is no study specifically focusing on the epidemiology of hip and groin injuries in MLB or Minor League Baseball (MiLB) players. The incidence of all injuries in professional baseball players has steadily increased over the last 2 decades,⁸ and the reported incidence of hip and groin injuries will likely increase as well. The current incidence of this injury, the positions most at risk, the mechanism of injury, and the time to return to sport are important to understand given the large number of players who participate in baseball not only at a professional level, but also at an amateur level, where this information may also be applicable. This information could improve our efforts at prevention and rehabilitation of these injuries, and can guide efforts to counsel and train players at high risk of a hip or groin injury. To address this gap in the literature, the purpose of this study was to describe the epidemiology of hip and groin injuries in MLB and MiLB players from 2011 to 2014.

Materials and Methods

Population and Sample

US MLB is comprised of the major and minor leagues. The major leagues are divided into 30 clubs, with 25 active players, for a total of 750 active players. Each club has a 40-man roster consisting of 25 active players and up to 15 additional players who are either not active or optioned to the minor leagues. The minor leagues are comprised of a network of over 200 clubs that are each affiliated with a major league club, and organized by geography and level of play. The minor leagues consist of roughly 7500 players, of whom about 6500 are actively playing at any given time. The entire population of players in the MLB who sustained a hip or groin injury over the study period was eligible for this study.

Data

The MLB’s Health and Injury Tracking System (HITS) is a centralized database that contains the de-identified medical data from the electronic medical record (EMR) system. Data on all injuries are entered into the EMR by each team’s certified athletic trainer. An injury is defined as any physical complaint sustained by a player that affects or limits participation in any aspect of baseball-related activity (eg, game, practice, warm-up, conditioning, weight training). The data extracted from HITS only relates to injuries that resulted in lost game time for a player and that occurred during spring training, regular season, or postseason play; off-season injuries were not included. Injury events that were classified as “season-ending” were not included in the analysis of assessing days missed because many of these players may not have been cleared to play until the beginning of the following season. For each injury, data were collected on the diagnosis, body part, activity, location, and date of injury.

 

Materials and Methods

Hip and groin injuries were defined as cases having a body region variable classified as “hip/groin” or a Sports Medicine Diagnostic Coding System (SMDCS) that included any “adductor” or “hernia” or “hip pointer” labels. Cases categorized as inguinal and femoral hernia (n = 26) and testicular contusions (n = 87) were excluded. Characteristics about each hip and groin injury were also extracted from HITS. These variables included level of play, player position (activity at the time of injury), field location, injury mechanism, chronicity of the injury, and days missed. Chronicity of the injury was documented as acute, overuse, or undetermined. For level of play, the injury event was categorized as the league in which the game was played when the injury occurred. Players were excluded if they had an unknown level of play or were in the amateur league. The injuries of the hip and groin were further classified as intra-articular and extra-articular. Treatment for each injury was characterized as surgical or nonsurgical, and correlated with days missed for each type of injury.

Statistical Analysis

Data for the 2011-2014 seasons were combined, and results presented for all players and separately for MiLB and MLB. Frequencies and comparative analyses for hip and groin injuries were performed across the aforementioned injury characteristics. The distribution of days missed for the variables considered was often skewed to the right, even after excluding the season-ending injuries; hence, the mean days missed was often larger than the median days missed. Reporting the median would allow for a robust estimate of the expected number of days missed, but would down weight those instances when hip and groin injuries result in much longer missed days, as reflected by the mean. Because of the importance of the days missed measure for professional baseball, both the mean and median are presented. Chi-square tests were used to test the hypothesis of equal proportions between the various categories of hip and groin characteristics, with statistical significance determined at the P = .05 level.

In order to estimate exposure, the average number of players per team per game was calculated based on analysis of regular season game participation via box scores that are publicly available. This average number over a season, multiplied by the number of team games at each professional level of baseball, was used as an estimate of athlete exposures in order to provide rates comparable to those of other injury surveillance systems. Injury rates were reported as injuries per 1000 athlete-exposures (AE) for those hip and groin injuries that occurred during the regular season. It should be noted that the number of regular season hip and groin injuries and the subsequent AE rates are based on injuries that were deemed work-related during the regular season. This does not necessarily only include injuries occurring during the course of a game, but injuries in game preparation as well. Due to the variations in spring training games and fluctuating rosters, an exposure rate could not be calculated for spring training hip and groin injuries.

Data analysis was performed in the R statistical computing Environment (R Core Team 2014). Study procedures were approved by the Johns Hopkins Bloomberg School of Public Health Institutional Review Board.

Results

Overall Summary

A total of 1823 hip and groin injuries occurred from 2011-2014, with 83% occurring in MiLB and 17% occurring in MLB (Table 1). There were 1146 acute injuries, 252 overuse injuries, and 425 injuries of undetermined chronicity. The average age of players experiencing a hip and groin injury in MiLB was 22.9 years compared to 29.7 years in MLB. Of the 1514 hip and groin injuries in MiLB, 76 (5.0%) required surgery and of the 309 hip and groin injuries in MLB, 24 (7.8%) required surgery. Compared to league-wide injury events, hip and groin injuries ranked 6th highest in prevalence in MiLB and 8th highest in prevalence in MLB, accounting for 5.4% and 5.6%, respectively, of the 28,116 MiLB and 5507 MLB injury events that occurred between 2011-2014.

For regular season games, it was estimated that there were 1,197,738 MiLB and 276,608 MLB AE from 2011-2014. The overall hip and groin rate across both MLB and MiLB was 1.2 per 1000 AE, based on the 238 and 1152 regular season hip and groin injuries in MLB and MiLB, respectively. The rate of hip and groin injury was 1.5 times more likely in MiLB than in MLB (P < .0001) (rate of 1.26 per 1000 AE in MiLB and 0.86 per 1000 AE in MLB).

 

Characteristics of Injuries

Injury activity was based on the position being played at the time of injury, with categories of infield and outfield corresponding to fielding activities (defense), with batting and base runner categories corresponding to activities while on offense (Table 2). The occurrence of hip and groin injuries while players are fielding on defense (MiLB 33.0%, MLB 37.2%, all players 33.8%) was significantly greater compared to injuries while batting and base running on offense (MiLB 24.9%, MLB 21.7%, all players 24.3%) (all P values < .001). There was a high percentage of missing data for the event position variable, which resulted from this field not being available in HITS for 2011. Time lost due to hip and groin injuries was similar across leagues with respect to injury activity, ranging on average between 8 and 18 days.

There were statistically significant differences for MiLB and MLB separately, and combined, in the number of hip and groin injuries by field location (all P values < .0001) (Table 2). For MiLB, MLB, and across both leagues, by injury location, the majority of hip and groin injuries occurred in the infield (MiLB 34.1%, MLB 35.3%, all players 34.3%). As a single location, the pitcher’s mound accounted for a large proportion of hip and groin injuries (MiLB 19.2%, MLB 23.3%, all players 19.9%). Time lost due to hip and groin injuries was similar across leagues with respect to field location, ranging on average between about 10 and 22 days. Among all players, injuries on the pitcher’s mound resulted in the largest mean days missed after injury.

There were statistically significant differences across the mechanisms of injury for MiLB and MLB, as well as both leagues combined (all P values < .0001) (Table 2). The majority of hip and groin injuries were noncontact-related (MiLB 73.7%, MLB 75.7%, all players 74.1%) compared to those resulting from some form of contact (MiLB 11.4%, MLB 12.6%, all players 11.7%) or other mechanisms. Time lost across these mechanisms varied, ranging on average between 4 and 15 days with noncontact-related hip and groin injuries resulting in the largest time lost.

Surgery

The 1823 hip and groin injuries across both leagues were further classified using the SMDCS descriptions as intra-articular (N = 84) or extra-articular (N = 1739) (Table 3). A much larger percentage of hip and groin injuries were extra-articular (MiLB 95.6%, MLB 94.4%, all players 95.4%) compared to those classified as intra-articular (Table 3). The most common extra-articular injuries were strains or contusions of the adductor, iliopsoas, or gluteal muscles, making up 79.1% of this group of injuries. The most common intra-articular injuries were FAI and a labral tear, accounting for 80.9% of these injuries. Only a small percentage of the extra-articular cases required surgery (MiLB 3.4%, MLB 5.8%, all players 3.8%) (Table 4). This finding was in contrast to the larger percentage of intra-articular cases requiring surgery (MiLB 40.3%, MLB 41.2%, all players 40.5%). Time lost varied greatly by surgery status, as well as extra-articular or intra-articular, as would be expected even after excluding season-ending injuries. For both types of injuries, the average time lost was consistently greater for injuries that required surgery versus the ones that did not result in surgery.

Discussion

The incidence of overall injuries in MLB players is increasing.⁸ Injuries to the hip and groin for professional baseball players continue to be of concern both in the number of injuries and the potential for these injuries to be debilitating or to recur. The correct diagnosis of hip injuries can be challenging in these athletes due to the complex anatomy of the region. However, our understanding of the pathoanatomy of hip and groin injuries, combined with the utilization of improved magnetic resonance imaging (MRI,) has aided in making the correct diagnosis more reliable. Although upper extremity injuries have traditionally been the focus of MLB injury reporting, hip injuries have been shown to cause an average of 23 days missed per player.⁴ This was similar to the more commonly highlighted elbow and knee injuries in the same study (23 and 27 days, respectively). The purpose of this study was to explore the epidemiology of hip and groin injuries in MLB. The lack of existing data on this issue is important for sports injury research. Exploring these injuries increases the understanding of which players are at risk, and how we can tailor training programs for prevention or rehabilitation programs for those players who suffer these injuries.

In addition to the increased awareness of hip injuries, there has been a recent focus on the contribution of hip range of motion, leg drive, and pelvic rotation to the overall mechanics of overhead activities such as throwing, a tennis serve, or pitching.¹² Pelvic rotation and leg drive have been correlated to throwing velocity,²¹ and therefore if hip range of motion is inhibited by pain or a structural issue such as FAI, there will likely be altered upper extremity mechanics leading to less power and possibly injury.¹² Additionally, it has been shown that limited hip range of motion due to FAI is correlated with compensatory lower extremity muscular injuries such as hamstring and adductor strains as well as overload of the lumbar spine and sacroiliac joint.²²

 

In the current study, extra-articular injuries about the hip were the most common, making up 95.4% of the total injuries. Many (79.1%) of these were strains or contusions of the adductor, iliopsoas, or gluteal muscles. This is consistent with other articles reporting hip injuries in athletes.^3,9 A study on hip injuries in the National Football League found that strains and contusions comprised 92% of all hip injuries.³ Another report on European professional football found that 72% of hip injuries over a 7-season period were adductor or iliopsoas injuries.⁹ This prior study also reported that 15% of the hip and groin strains were re-injuries. Intra-articular injuries comprised only 4.6% of the hip injuries in our study. FAI and labral tears were the most common intra-articular diagnosis at 80.9%.

Almost all (96.2%) of the extra-articular hip injuries in this series were able to be treated nonoperatively and caused a mean of 12.4 days missed. Those which required operative treatment caused a mean of 54.6 days missed. For intra-articular injuries, 40.5% were treated surgically and these players missed a mean 122.5 days. Those treated nonsurgically missed an average of 22.2 days. Whether treated surgically or nonsurgically, the mean days missed following an intra-articular injury was approximately twice that of extra-articular injuries. Our findings regarding time or games missed are similar to other reports studying hip injuries in professional athletes.^2,3,9 Intra-articular injuries such as FAI, chondral injuries, or labral tears caused between 46 and 64 days missed compared to 3 to 27 days missed for extra-articular injuries in professional soccer players.⁹ Feeley and colleagues³ found a mean of 5.07 to 33.6 days missed for extra-articular injuries such as strains or contusions, and 63.5 to 126.2 days missed for intra-articular injuries including arthritis, labral tears, subluxations, dislocations, and fractures. A report on National Hockey League players found that intra-articular injuries made up 10.6% of all hip and groin injuries and caused significantly more games missed than extra-articular injuries.²

In both minor and major league players, for all reported positions at the time of hip or groin injury, infield players collectively were more commonly injured than outfielders, batters, or base runners, and fielding was the most common activity being performed at the time of injury. The pitcher’s mound was the most common single location for injuries and these players had the longest time missed following injury. The correlation between hip and groin pathology and upper extremity injuries in overhead athletes has been discussed in previous studies.^12,21 Interestingly, we found that the specific location on the field with the highest incidence of hip and groin injuries was the pitcher’s mound. As we follow these players over time, a future correlation between the incidence of hip and groin injuries and the incidence of shoulder and elbow injuries may be noted. A noncontact injury was the most frequent mechanism of injury. This corroborates the finding that muscle strains and contusions made up the majority of injuries in this series. Other series on hip injuries have also found that noncontact mechanisms are common.³

Although this was one of the first studies exploring the epidemiology of hip and groin injury, there are some limitations of this study. The retrospective nature of this study relied upon the reporting of injuries in the MLB database. As such, there may be underreporting of injuries into the official database by players or medical staff for a variety of reasons. Differences in technique for diagnosis and treatment among the medical staff for different teams were not controlled for. Due to the wide range of hip and groin pathology, and the often difficult diagnosis, a specific injury was not always provided. Therefore, the category of “other” hip injury was entered in to the database when symptoms were nonspecific or not all details were provided. Fortunately, this category made up a small percentage of the reported injuries, but does remain a confounding factor in describing the etiology of hip injuries in these players. Our data were taken from professional baseball players only, and so we cannot recommend extrapolation to other sports or nonprofessional baseball athletes.

Despite the inherent limitations of reporting registry data, this study serves as the initial report of the occurrence of hip and groin injuries in professional baseball players, and improves our knowledge of the positions and situations that put players at most risk for these injuries. An understanding of the overall epidemiology of these injuries serves as a platform for more focused research in this area in the future. We can now focus research on specific positions, such as pitchers, that have a high incidence of injury to determine the physiologic and environmental factors which put them at higher risk for injury in general and for more significant injuries with more days missed. This information can help to guide position-specific training programs for injury prevention as well as improve rehabilitation protocols for more efficient recovery and return to sports.

Injuries around the hip and groin occurring in professional baseball players can present as muscle strains, avulsions, contusions, hip subluxations or dislocations, femoroacetabular impingement (FAI) causing labral tears or chondral defects, and athletic pubalgia.^1-9 Several recent articles have reported on the epidemiology of musculoskeletal injuries in Major League Baseball (MLB) players^4,8,10 but with little attention to injuries to the hip and groin, likely because prior studies show only a 6.3% overall incidence for these injuries, much less than the more commonly discussed shoulder or elbow injuries.⁸ Despite the lower proportion of hip and groin injuries overall, these injuries lead to a relatively long period of disability for the players and often have a high rate of recurrence.^4,8,9

The important contribution of hip mechanics and the surrounding muscular function in the kinetic chain during overhead athletic activities, such as a tennis serve or throwing, has recently been discussed.^11,12 In sports requiring overhead activities, trunk rotation is a key component to generating force, and hip internal and external rotation is necessary for this trunk rotation to occur.^12,13 Alterations in hip morphology causing constrained motion, as seen in FAI, may predispose an overhead throwing athlete to intra-articular injury such as labral tears or chondral injuries, or to a compensatory movement pattern causing an extra-articular soft tissue injury about the hip.¹² Decreased hip range of motion may also lead to increased forces across the upper extremity during the throwing motion, which puts the shoulder and elbow at increased risk of injury.¹²

Increased awareness of hip and groin injuries, advances in diagnostic imaging, and an understanding of the relationship between the throwing motion in baseball and hip mechanics have improved our ability to appropriately identify and treat athletes with injuries of the hip and groin. Several studies on hip and groin injuries in elite athletes treated both operatively and nonoperatively have reported a high rate of return to sport.^3,7,14-19 A systematic review on return to sport following hip arthroscopy for intra-articular pathology associated with FAI showed a 95% return to sport rate and a 92% rate of return to pre-injury level of play in a subgroup of professional athletes in 9 studies.²⁰

Despite the large body of literature on upper extremity injuries, there is no study specifically focusing on the epidemiology of hip and groin injuries in MLB or Minor League Baseball (MiLB) players. The incidence of all injuries in professional baseball players has steadily increased over the last 2 decades,⁸ and the reported incidence of hip and groin injuries will likely increase as well. The current incidence of this injury, the positions most at risk, the mechanism of injury, and the time to return to sport are important to understand given the large number of players who participate in baseball not only at a professional level, but also at an amateur level, where this information may also be applicable. This information could improve our efforts at prevention and rehabilitation of these injuries, and can guide efforts to counsel and train players at high risk of a hip or groin injury. To address this gap in the literature, the purpose of this study was to describe the epidemiology of hip and groin injuries in MLB and MiLB players from 2011 to 2014.

Materials and Methods

Population and Sample

US MLB is comprised of the major and minor leagues. The major leagues are divided into 30 clubs, with 25 active players, for a total of 750 active players. Each club has a 40-man roster consisting of 25 active players and up to 15 additional players who are either not active or optioned to the minor leagues. The minor leagues are comprised of a network of over 200 clubs that are each affiliated with a major league club, and organized by geography and level of play. The minor leagues consist of roughly 7500 players, of whom about 6500 are actively playing at any given time. The entire population of players in the MLB who sustained a hip or groin injury over the study period was eligible for this study.

Data

The MLB’s Health and Injury Tracking System (HITS) is a centralized database that contains the de-identified medical data from the electronic medical record (EMR) system. Data on all injuries are entered into the EMR by each team’s certified athletic trainer. An injury is defined as any physical complaint sustained by a player that affects or limits participation in any aspect of baseball-related activity (eg, game, practice, warm-up, conditioning, weight training). The data extracted from HITS only relates to injuries that resulted in lost game time for a player and that occurred during spring training, regular season, or postseason play; off-season injuries were not included. Injury events that were classified as “season-ending” were not included in the analysis of assessing days missed because many of these players may not have been cleared to play until the beginning of the following season. For each injury, data were collected on the diagnosis, body part, activity, location, and date of injury.

 

Materials and Methods

Hip and groin injuries were defined as cases having a body region variable classified as “hip/groin” or a Sports Medicine Diagnostic Coding System (SMDCS) that included any “adductor” or “hernia” or “hip pointer” labels. Cases categorized as inguinal and femoral hernia (n = 26) and testicular contusions (n = 87) were excluded. Characteristics about each hip and groin injury were also extracted from HITS. These variables included level of play, player position (activity at the time of injury), field location, injury mechanism, chronicity of the injury, and days missed. Chronicity of the injury was documented as acute, overuse, or undetermined. For level of play, the injury event was categorized as the league in which the game was played when the injury occurred. Players were excluded if they had an unknown level of play or were in the amateur league. The injuries of the hip and groin were further classified as intra-articular and extra-articular. Treatment for each injury was characterized as surgical or nonsurgical, and correlated with days missed for each type of injury.

Statistical Analysis

Data for the 2011-2014 seasons were combined, and results presented for all players and separately for MiLB and MLB. Frequencies and comparative analyses for hip and groin injuries were performed across the aforementioned injury characteristics. The distribution of days missed for the variables considered was often skewed to the right, even after excluding the season-ending injuries; hence, the mean days missed was often larger than the median days missed. Reporting the median would allow for a robust estimate of the expected number of days missed, but would down weight those instances when hip and groin injuries result in much longer missed days, as reflected by the mean. Because of the importance of the days missed measure for professional baseball, both the mean and median are presented. Chi-square tests were used to test the hypothesis of equal proportions between the various categories of hip and groin characteristics, with statistical significance determined at the P = .05 level.

In order to estimate exposure, the average number of players per team per game was calculated based on analysis of regular season game participation via box scores that are publicly available. This average number over a season, multiplied by the number of team games at each professional level of baseball, was used as an estimate of athlete exposures in order to provide rates comparable to those of other injury surveillance systems. Injury rates were reported as injuries per 1000 athlete-exposures (AE) for those hip and groin injuries that occurred during the regular season. It should be noted that the number of regular season hip and groin injuries and the subsequent AE rates are based on injuries that were deemed work-related during the regular season. This does not necessarily only include injuries occurring during the course of a game, but injuries in game preparation as well. Due to the variations in spring training games and fluctuating rosters, an exposure rate could not be calculated for spring training hip and groin injuries.

Data analysis was performed in the R statistical computing Environment (R Core Team 2014). Study procedures were approved by the Johns Hopkins Bloomberg School of Public Health Institutional Review Board.

Results

Overall Summary

A total of 1823 hip and groin injuries occurred from 2011-2014, with 83% occurring in MiLB and 17% occurring in MLB (Table 1). There were 1146 acute injuries, 252 overuse injuries, and 425 injuries of undetermined chronicity. The average age of players experiencing a hip and groin injury in MiLB was 22.9 years compared to 29.7 years in MLB. Of the 1514 hip and groin injuries in MiLB, 76 (5.0%) required surgery and of the 309 hip and groin injuries in MLB, 24 (7.8%) required surgery. Compared to league-wide injury events, hip and groin injuries ranked 6th highest in prevalence in MiLB and 8th highest in prevalence in MLB, accounting for 5.4% and 5.6%, respectively, of the 28,116 MiLB and 5507 MLB injury events that occurred between 2011-2014.

For regular season games, it was estimated that there were 1,197,738 MiLB and 276,608 MLB AE from 2011-2014. The overall hip and groin rate across both MLB and MiLB was 1.2 per 1000 AE, based on the 238 and 1152 regular season hip and groin injuries in MLB and MiLB, respectively. The rate of hip and groin injury was 1.5 times more likely in MiLB than in MLB (P < .0001) (rate of 1.26 per 1000 AE in MiLB and 0.86 per 1000 AE in MLB).

 

Characteristics of Injuries

Injury activity was based on the position being played at the time of injury, with categories of infield and outfield corresponding to fielding activities (defense), with batting and base runner categories corresponding to activities while on offense (Table 2). The occurrence of hip and groin injuries while players are fielding on defense (MiLB 33.0%, MLB 37.2%, all players 33.8%) was significantly greater compared to injuries while batting and base running on offense (MiLB 24.9%, MLB 21.7%, all players 24.3%) (all P values < .001). There was a high percentage of missing data for the event position variable, which resulted from this field not being available in HITS for 2011. Time lost due to hip and groin injuries was similar across leagues with respect to injury activity, ranging on average between 8 and 18 days.

There were statistically significant differences for MiLB and MLB separately, and combined, in the number of hip and groin injuries by field location (all P values < .0001) (Table 2). For MiLB, MLB, and across both leagues, by injury location, the majority of hip and groin injuries occurred in the infield (MiLB 34.1%, MLB 35.3%, all players 34.3%). As a single location, the pitcher’s mound accounted for a large proportion of hip and groin injuries (MiLB 19.2%, MLB 23.3%, all players 19.9%). Time lost due to hip and groin injuries was similar across leagues with respect to field location, ranging on average between about 10 and 22 days. Among all players, injuries on the pitcher’s mound resulted in the largest mean days missed after injury.

There were statistically significant differences across the mechanisms of injury for MiLB and MLB, as well as both leagues combined (all P values < .0001) (Table 2). The majority of hip and groin injuries were noncontact-related (MiLB 73.7%, MLB 75.7%, all players 74.1%) compared to those resulting from some form of contact (MiLB 11.4%, MLB 12.6%, all players 11.7%) or other mechanisms. Time lost across these mechanisms varied, ranging on average between 4 and 15 days with noncontact-related hip and groin injuries resulting in the largest time lost.

Surgery

The 1823 hip and groin injuries across both leagues were further classified using the SMDCS descriptions as intra-articular (N = 84) or extra-articular (N = 1739) (Table 3). A much larger percentage of hip and groin injuries were extra-articular (MiLB 95.6%, MLB 94.4%, all players 95.4%) compared to those classified as intra-articular (Table 3). The most common extra-articular injuries were strains or contusions of the adductor, iliopsoas, or gluteal muscles, making up 79.1% of this group of injuries. The most common intra-articular injuries were FAI and a labral tear, accounting for 80.9% of these injuries. Only a small percentage of the extra-articular cases required surgery (MiLB 3.4%, MLB 5.8%, all players 3.8%) (Table 4). This finding was in contrast to the larger percentage of intra-articular cases requiring surgery (MiLB 40.3%, MLB 41.2%, all players 40.5%). Time lost varied greatly by surgery status, as well as extra-articular or intra-articular, as would be expected even after excluding season-ending injuries. For both types of injuries, the average time lost was consistently greater for injuries that required surgery versus the ones that did not result in surgery.

Discussion

The incidence of overall injuries in MLB players is increasing.⁸ Injuries to the hip and groin for professional baseball players continue to be of concern both in the number of injuries and the potential for these injuries to be debilitating or to recur. The correct diagnosis of hip injuries can be challenging in these athletes due to the complex anatomy of the region. However, our understanding of the pathoanatomy of hip and groin injuries, combined with the utilization of improved magnetic resonance imaging (MRI,) has aided in making the correct diagnosis more reliable. Although upper extremity injuries have traditionally been the focus of MLB injury reporting, hip injuries have been shown to cause an average of 23 days missed per player.⁴ This was similar to the more commonly highlighted elbow and knee injuries in the same study (23 and 27 days, respectively). The purpose of this study was to explore the epidemiology of hip and groin injuries in MLB. The lack of existing data on this issue is important for sports injury research. Exploring these injuries increases the understanding of which players are at risk, and how we can tailor training programs for prevention or rehabilitation programs for those players who suffer these injuries.

In addition to the increased awareness of hip injuries, there has been a recent focus on the contribution of hip range of motion, leg drive, and pelvic rotation to the overall mechanics of overhead activities such as throwing, a tennis serve, or pitching.¹² Pelvic rotation and leg drive have been correlated to throwing velocity,²¹ and therefore if hip range of motion is inhibited by pain or a structural issue such as FAI, there will likely be altered upper extremity mechanics leading to less power and possibly injury.¹² Additionally, it has been shown that limited hip range of motion due to FAI is correlated with compensatory lower extremity muscular injuries such as hamstring and adductor strains as well as overload of the lumbar spine and sacroiliac joint.²²

 

In the current study, extra-articular injuries about the hip were the most common, making up 95.4% of the total injuries. Many (79.1%) of these were strains or contusions of the adductor, iliopsoas, or gluteal muscles. This is consistent with other articles reporting hip injuries in athletes.^3,9 A study on hip injuries in the National Football League found that strains and contusions comprised 92% of all hip injuries.³ Another report on European professional football found that 72% of hip injuries over a 7-season period were adductor or iliopsoas injuries.⁹ This prior study also reported that 15% of the hip and groin strains were re-injuries. Intra-articular injuries comprised only 4.6% of the hip injuries in our study. FAI and labral tears were the most common intra-articular diagnosis at 80.9%.

Almost all (96.2%) of the extra-articular hip injuries in this series were able to be treated nonoperatively and caused a mean of 12.4 days missed. Those which required operative treatment caused a mean of 54.6 days missed. For intra-articular injuries, 40.5% were treated surgically and these players missed a mean 122.5 days. Those treated nonsurgically missed an average of 22.2 days. Whether treated surgically or nonsurgically, the mean days missed following an intra-articular injury was approximately twice that of extra-articular injuries. Our findings regarding time or games missed are similar to other reports studying hip injuries in professional athletes.^2,3,9 Intra-articular injuries such as FAI, chondral injuries, or labral tears caused between 46 and 64 days missed compared to 3 to 27 days missed for extra-articular injuries in professional soccer players.⁹ Feeley and colleagues³ found a mean of 5.07 to 33.6 days missed for extra-articular injuries such as strains or contusions, and 63.5 to 126.2 days missed for intra-articular injuries including arthritis, labral tears, subluxations, dislocations, and fractures. A report on National Hockey League players found that intra-articular injuries made up 10.6% of all hip and groin injuries and caused significantly more games missed than extra-articular injuries.²

In both minor and major league players, for all reported positions at the time of hip or groin injury, infield players collectively were more commonly injured than outfielders, batters, or base runners, and fielding was the most common activity being performed at the time of injury. The pitcher’s mound was the most common single location for injuries and these players had the longest time missed following injury. The correlation between hip and groin pathology and upper extremity injuries in overhead athletes has been discussed in previous studies.^12,21 Interestingly, we found that the specific location on the field with the highest incidence of hip and groin injuries was the pitcher’s mound. As we follow these players over time, a future correlation between the incidence of hip and groin injuries and the incidence of shoulder and elbow injuries may be noted. A noncontact injury was the most frequent mechanism of injury. This corroborates the finding that muscle strains and contusions made up the majority of injuries in this series. Other series on hip injuries have also found that noncontact mechanisms are common.³

Although this was one of the first studies exploring the epidemiology of hip and groin injury, there are some limitations of this study. The retrospective nature of this study relied upon the reporting of injuries in the MLB database. As such, there may be underreporting of injuries into the official database by players or medical staff for a variety of reasons. Differences in technique for diagnosis and treatment among the medical staff for different teams were not controlled for. Due to the wide range of hip and groin pathology, and the often difficult diagnosis, a specific injury was not always provided. Therefore, the category of “other” hip injury was entered in to the database when symptoms were nonspecific or not all details were provided. Fortunately, this category made up a small percentage of the reported injuries, but does remain a confounding factor in describing the etiology of hip injuries in these players. Our data were taken from professional baseball players only, and so we cannot recommend extrapolation to other sports or nonprofessional baseball athletes.

Despite the inherent limitations of reporting registry data, this study serves as the initial report of the occurrence of hip and groin injuries in professional baseball players, and improves our knowledge of the positions and situations that put players at most risk for these injuries. An understanding of the overall epidemiology of these injuries serves as a platform for more focused research in this area in the future. We can now focus research on specific positions, such as pitchers, that have a high incidence of injury to determine the physiologic and environmental factors which put them at higher risk for injury in general and for more significant injuries with more days missed. This information can help to guide position-specific training programs for injury prevention as well as improve rehabilitation protocols for more efficient recovery and return to sports.

Injuries around the hip and groin occurring in professional baseball players can present as muscle strains, avulsions, contusions, hip subluxations or dislocations, femoroacetabular impingement (FAI) causing labral tears or chondral defects, and athletic pubalgia.^1-9 Several recent articles have reported on the epidemiology of musculoskeletal injuries in Major League Baseball (MLB) players^4,8,10 but with little attention to injuries to the hip and groin, likely because prior studies show only a 6.3% overall incidence for these injuries, much less than the more commonly discussed shoulder or elbow injuries.⁸ Despite the lower proportion of hip and groin injuries overall, these injuries lead to a relatively long period of disability for the players and often have a high rate of recurrence.^4,8,9

The important contribution of hip mechanics and the surrounding muscular function in the kinetic chain during overhead athletic activities, such as a tennis serve or throwing, has recently been discussed.^11,12 In sports requiring overhead activities, trunk rotation is a key component to generating force, and hip internal and external rotation is necessary for this trunk rotation to occur.^12,13 Alterations in hip morphology causing constrained motion, as seen in FAI, may predispose an overhead throwing athlete to intra-articular injury such as labral tears or chondral injuries, or to a compensatory movement pattern causing an extra-articular soft tissue injury about the hip.¹² Decreased hip range of motion may also lead to increased forces across the upper extremity during the throwing motion, which puts the shoulder and elbow at increased risk of injury.¹²

Increased awareness of hip and groin injuries, advances in diagnostic imaging, and an understanding of the relationship between the throwing motion in baseball and hip mechanics have improved our ability to appropriately identify and treat athletes with injuries of the hip and groin. Several studies on hip and groin injuries in elite athletes treated both operatively and nonoperatively have reported a high rate of return to sport.^3,7,14-19 A systematic review on return to sport following hip arthroscopy for intra-articular pathology associated with FAI showed a 95% return to sport rate and a 92% rate of return to pre-injury level of play in a subgroup of professional athletes in 9 studies.²⁰

Despite the large body of literature on upper extremity injuries, there is no study specifically focusing on the epidemiology of hip and groin injuries in MLB or Minor League Baseball (MiLB) players. The incidence of all injuries in professional baseball players has steadily increased over the last 2 decades,⁸ and the reported incidence of hip and groin injuries will likely increase as well. The current incidence of this injury, the positions most at risk, the mechanism of injury, and the time to return to sport are important to understand given the large number of players who participate in baseball not only at a professional level, but also at an amateur level, where this information may also be applicable. This information could improve our efforts at prevention and rehabilitation of these injuries, and can guide efforts to counsel and train players at high risk of a hip or groin injury. To address this gap in the literature, the purpose of this study was to describe the epidemiology of hip and groin injuries in MLB and MiLB players from 2011 to 2014.

Materials and Methods

Population and Sample

US MLB is comprised of the major and minor leagues. The major leagues are divided into 30 clubs, with 25 active players, for a total of 750 active players. Each club has a 40-man roster consisting of 25 active players and up to 15 additional players who are either not active or optioned to the minor leagues. The minor leagues are comprised of a network of over 200 clubs that are each affiliated with a major league club, and organized by geography and level of play. The minor leagues consist of roughly 7500 players, of whom about 6500 are actively playing at any given time. The entire population of players in the MLB who sustained a hip or groin injury over the study period was eligible for this study.

Data

The MLB’s Health and Injury Tracking System (HITS) is a centralized database that contains the de-identified medical data from the electronic medical record (EMR) system. Data on all injuries are entered into the EMR by each team’s certified athletic trainer. An injury is defined as any physical complaint sustained by a player that affects or limits participation in any aspect of baseball-related activity (eg, game, practice, warm-up, conditioning, weight training). The data extracted from HITS only relates to injuries that resulted in lost game time for a player and that occurred during spring training, regular season, or postseason play; off-season injuries were not included. Injury events that were classified as “season-ending” were not included in the analysis of assessing days missed because many of these players may not have been cleared to play until the beginning of the following season. For each injury, data were collected on the diagnosis, body part, activity, location, and date of injury.

 

Materials and Methods

Hip and groin injuries were defined as cases having a body region variable classified as “hip/groin” or a Sports Medicine Diagnostic Coding System (SMDCS) that included any “adductor” or “hernia” or “hip pointer” labels. Cases categorized as inguinal and femoral hernia (n = 26) and testicular contusions (n = 87) were excluded. Characteristics about each hip and groin injury were also extracted from HITS. These variables included level of play, player position (activity at the time of injury), field location, injury mechanism, chronicity of the injury, and days missed. Chronicity of the injury was documented as acute, overuse, or undetermined. For level of play, the injury event was categorized as the league in which the game was played when the injury occurred. Players were excluded if they had an unknown level of play or were in the amateur league. The injuries of the hip and groin were further classified as intra-articular and extra-articular. Treatment for each injury was characterized as surgical or nonsurgical, and correlated with days missed for each type of injury.

Statistical Analysis

Data for the 2011-2014 seasons were combined, and results presented for all players and separately for MiLB and MLB. Frequencies and comparative analyses for hip and groin injuries were performed across the aforementioned injury characteristics. The distribution of days missed for the variables considered was often skewed to the right, even after excluding the season-ending injuries; hence, the mean days missed was often larger than the median days missed. Reporting the median would allow for a robust estimate of the expected number of days missed, but would down weight those instances when hip and groin injuries result in much longer missed days, as reflected by the mean. Because of the importance of the days missed measure for professional baseball, both the mean and median are presented. Chi-square tests were used to test the hypothesis of equal proportions between the various categories of hip and groin characteristics, with statistical significance determined at the P = .05 level.

In order to estimate exposure, the average number of players per team per game was calculated based on analysis of regular season game participation via box scores that are publicly available. This average number over a season, multiplied by the number of team games at each professional level of baseball, was used as an estimate of athlete exposures in order to provide rates comparable to those of other injury surveillance systems. Injury rates were reported as injuries per 1000 athlete-exposures (AE) for those hip and groin injuries that occurred during the regular season. It should be noted that the number of regular season hip and groin injuries and the subsequent AE rates are based on injuries that were deemed work-related during the regular season. This does not necessarily only include injuries occurring during the course of a game, but injuries in game preparation as well. Due to the variations in spring training games and fluctuating rosters, an exposure rate could not be calculated for spring training hip and groin injuries.

Data analysis was performed in the R statistical computing Environment (R Core Team 2014). Study procedures were approved by the Johns Hopkins Bloomberg School of Public Health Institutional Review Board.

Results

Overall Summary

A total of 1823 hip and groin injuries occurred from 2011-2014, with 83% occurring in MiLB and 17% occurring in MLB (Table 1). There were 1146 acute injuries, 252 overuse injuries, and 425 injuries of undetermined chronicity. The average age of players experiencing a hip and groin injury in MiLB was 22.9 years compared to 29.7 years in MLB. Of the 1514 hip and groin injuries in MiLB, 76 (5.0%) required surgery and of the 309 hip and groin injuries in MLB, 24 (7.8%) required surgery. Compared to league-wide injury events, hip and groin injuries ranked 6th highest in prevalence in MiLB and 8th highest in prevalence in MLB, accounting for 5.4% and 5.6%, respectively, of the 28,116 MiLB and 5507 MLB injury events that occurred between 2011-2014.

For regular season games, it was estimated that there were 1,197,738 MiLB and 276,608 MLB AE from 2011-2014. The overall hip and groin rate across both MLB and MiLB was 1.2 per 1000 AE, based on the 238 and 1152 regular season hip and groin injuries in MLB and MiLB, respectively. The rate of hip and groin injury was 1.5 times more likely in MiLB than in MLB (P < .0001) (rate of 1.26 per 1000 AE in MiLB and 0.86 per 1000 AE in MLB).

 

Characteristics of Injuries

Injury activity was based on the position being played at the time of injury, with categories of infield and outfield corresponding to fielding activities (defense), with batting and base runner categories corresponding to activities while on offense (Table 2). The occurrence of hip and groin injuries while players are fielding on defense (MiLB 33.0%, MLB 37.2%, all players 33.8%) was significantly greater compared to injuries while batting and base running on offense (MiLB 24.9%, MLB 21.7%, all players 24.3%) (all P values < .001). There was a high percentage of missing data for the event position variable, which resulted from this field not being available in HITS for 2011. Time lost due to hip and groin injuries was similar across leagues with respect to injury activity, ranging on average between 8 and 18 days.

There were statistically significant differences for MiLB and MLB separately, and combined, in the number of hip and groin injuries by field location (all P values < .0001) (Table 2). For MiLB, MLB, and across both leagues, by injury location, the majority of hip and groin injuries occurred in the infield (MiLB 34.1%, MLB 35.3%, all players 34.3%). As a single location, the pitcher’s mound accounted for a large proportion of hip and groin injuries (MiLB 19.2%, MLB 23.3%, all players 19.9%). Time lost due to hip and groin injuries was similar across leagues with respect to field location, ranging on average between about 10 and 22 days. Among all players, injuries on the pitcher’s mound resulted in the largest mean days missed after injury.

There were statistically significant differences across the mechanisms of injury for MiLB and MLB, as well as both leagues combined (all P values < .0001) (Table 2). The majority of hip and groin injuries were noncontact-related (MiLB 73.7%, MLB 75.7%, all players 74.1%) compared to those resulting from some form of contact (MiLB 11.4%, MLB 12.6%, all players 11.7%) or other mechanisms. Time lost across these mechanisms varied, ranging on average between 4 and 15 days with noncontact-related hip and groin injuries resulting in the largest time lost.

Surgery

The 1823 hip and groin injuries across both leagues were further classified using the SMDCS descriptions as intra-articular (N = 84) or extra-articular (N = 1739) (Table 3). A much larger percentage of hip and groin injuries were extra-articular (MiLB 95.6%, MLB 94.4%, all players 95.4%) compared to those classified as intra-articular (Table 3). The most common extra-articular injuries were strains or contusions of the adductor, iliopsoas, or gluteal muscles, making up 79.1% of this group of injuries. The most common intra-articular injuries were FAI and a labral tear, accounting for 80.9% of these injuries. Only a small percentage of the extra-articular cases required surgery (MiLB 3.4%, MLB 5.8%, all players 3.8%) (Table 4). This finding was in contrast to the larger percentage of intra-articular cases requiring surgery (MiLB 40.3%, MLB 41.2%, all players 40.5%). Time lost varied greatly by surgery status, as well as extra-articular or intra-articular, as would be expected even after excluding season-ending injuries. For both types of injuries, the average time lost was consistently greater for injuries that required surgery versus the ones that did not result in surgery.

Discussion

The incidence of overall injuries in MLB players is increasing.⁸ Injuries to the hip and groin for professional baseball players continue to be of concern both in the number of injuries and the potential for these injuries to be debilitating or to recur. The correct diagnosis of hip injuries can be challenging in these athletes due to the complex anatomy of the region. However, our understanding of the pathoanatomy of hip and groin injuries, combined with the utilization of improved magnetic resonance imaging (MRI,) has aided in making the correct diagnosis more reliable. Although upper extremity injuries have traditionally been the focus of MLB injury reporting, hip injuries have been shown to cause an average of 23 days missed per player.⁴ This was similar to the more commonly highlighted elbow and knee injuries in the same study (23 and 27 days, respectively). The purpose of this study was to explore the epidemiology of hip and groin injuries in MLB. The lack of existing data on this issue is important for sports injury research. Exploring these injuries increases the understanding of which players are at risk, and how we can tailor training programs for prevention or rehabilitation programs for those players who suffer these injuries.

In addition to the increased awareness of hip injuries, there has been a recent focus on the contribution of hip range of motion, leg drive, and pelvic rotation to the overall mechanics of overhead activities such as throwing, a tennis serve, or pitching.¹² Pelvic rotation and leg drive have been correlated to throwing velocity,²¹ and therefore if hip range of motion is inhibited by pain or a structural issue such as FAI, there will likely be altered upper extremity mechanics leading to less power and possibly injury.¹² Additionally, it has been shown that limited hip range of motion due to FAI is correlated with compensatory lower extremity muscular injuries such as hamstring and adductor strains as well as overload of the lumbar spine and sacroiliac joint.²²

 

In the current study, extra-articular injuries about the hip were the most common, making up 95.4% of the total injuries. Many (79.1%) of these were strains or contusions of the adductor, iliopsoas, or gluteal muscles. This is consistent with other articles reporting hip injuries in athletes.^3,9 A study on hip injuries in the National Football League found that strains and contusions comprised 92% of all hip injuries.³ Another report on European professional football found that 72% of hip injuries over a 7-season period were adductor or iliopsoas injuries.⁹ This prior study also reported that 15% of the hip and groin strains were re-injuries. Intra-articular injuries comprised only 4.6% of the hip injuries in our study. FAI and labral tears were the most common intra-articular diagnosis at 80.9%.

Almost all (96.2%) of the extra-articular hip injuries in this series were able to be treated nonoperatively and caused a mean of 12.4 days missed. Those which required operative treatment caused a mean of 54.6 days missed. For intra-articular injuries, 40.5% were treated surgically and these players missed a mean 122.5 days. Those treated nonsurgically missed an average of 22.2 days. Whether treated surgically or nonsurgically, the mean days missed following an intra-articular injury was approximately twice that of extra-articular injuries. Our findings regarding time or games missed are similar to other reports studying hip injuries in professional athletes.^2,3,9 Intra-articular injuries such as FAI, chondral injuries, or labral tears caused between 46 and 64 days missed compared to 3 to 27 days missed for extra-articular injuries in professional soccer players.⁹ Feeley and colleagues³ found a mean of 5.07 to 33.6 days missed for extra-articular injuries such as strains or contusions, and 63.5 to 126.2 days missed for intra-articular injuries including arthritis, labral tears, subluxations, dislocations, and fractures. A report on National Hockey League players found that intra-articular injuries made up 10.6% of all hip and groin injuries and caused significantly more games missed than extra-articular injuries.²

In both minor and major league players, for all reported positions at the time of hip or groin injury, infield players collectively were more commonly injured than outfielders, batters, or base runners, and fielding was the most common activity being performed at the time of injury. The pitcher’s mound was the most common single location for injuries and these players had the longest time missed following injury. The correlation between hip and groin pathology and upper extremity injuries in overhead athletes has been discussed in previous studies.^12,21 Interestingly, we found that the specific location on the field with the highest incidence of hip and groin injuries was the pitcher’s mound. As we follow these players over time, a future correlation between the incidence of hip and groin injuries and the incidence of shoulder and elbow injuries may be noted. A noncontact injury was the most frequent mechanism of injury. This corroborates the finding that muscle strains and contusions made up the majority of injuries in this series. Other series on hip injuries have also found that noncontact mechanisms are common.³

Although this was one of the first studies exploring the epidemiology of hip and groin injury, there are some limitations of this study. The retrospective nature of this study relied upon the reporting of injuries in the MLB database. As such, there may be underreporting of injuries into the official database by players or medical staff for a variety of reasons. Differences in technique for diagnosis and treatment among the medical staff for different teams were not controlled for. Due to the wide range of hip and groin pathology, and the often difficult diagnosis, a specific injury was not always provided. Therefore, the category of “other” hip injury was entered in to the database when symptoms were nonspecific or not all details were provided. Fortunately, this category made up a small percentage of the reported injuries, but does remain a confounding factor in describing the etiology of hip injuries in these players. Our data were taken from professional baseball players only, and so we cannot recommend extrapolation to other sports or nonprofessional baseball athletes.

Despite the inherent limitations of reporting registry data, this study serves as the initial report of the occurrence of hip and groin injuries in professional baseball players, and improves our knowledge of the positions and situations that put players at most risk for these injuries. An understanding of the overall epidemiology of these injuries serves as a platform for more focused research in this area in the future. We can now focus research on specific positions, such as pitchers, that have a high incidence of injury to determine the physiologic and environmental factors which put them at higher risk for injury in general and for more significant injuries with more days missed. This information can help to guide position-specific training programs for injury prevention as well as improve rehabilitation protocols for more efficient recovery and return to sports.

While the exact origins of the game of baseball are commonly debated, one thing is certain: statistics have been an integral part of the game since its existence.^1-3 This is true at nearly every level of baseball, especially in Major League Baseball (MLB). As our knowledge and technical capabilities advance, new statistical measures of baseball performance are added at a rapid pace.^1,3 One example is the Pitch f/x video tracking system (Sportvision, Inc.), which now analyzes over 60 variables on each of the estimated 660,000 pitches thrown in the MLB annually. In addition to measuring performance and production, these advancements are being leveraged to better understand the epidemiology and impact of injuries in MLB players.^4,5 As with any sport, performance at the most elite level is highly dependent upon player health and functional capacity. Accordingly, player injuries can have a profound impact not only on individual performance but also on the success of the team as a whole.

The first epidemiologic study of injuries in professional baseball was published by Conte and colleagues⁴ in 2001. This work utilized publically available disabled list (DL) data to perform a comprehensive review of injury patterns in MLB from 1989 to 1999. They demonstrated that injuries were on the rise and that pitchers were more commonly injured (48.4% of all DL reports) and had greater time out of play compared to players of other positions.⁴ Shoulder and elbow injuries were responsible for 49.8% of all DL assignments, distantly followed by knee (7.3%), wrist/hand (6.1%), and back (5.0%).⁴ In a later study, Posner and colleagues⁵ analyzed DL data spanning the 2002 to 2008 seasons. Similarly, they found that injuries continued to increase, and over half (51.2%) of DL assignments occurred secondary to upper extremity injuries.⁵ Although the DL is primarily designed as a roster management tool rather than an injury database, it has provided valuable epidemiologic injury information through the years. Out of concern for player health and well-being, MLB and the MLB Players Association (MLBPA) worked together to create and implement an electronic medical record and Health and Injury Tracking System (HITS) for all MLB and Minor League Baseball (MiLB) players. Now active for over 5 seasons, this database has provided valuable, detailed reports regarding specific injuries occurring in professional baseball, such as hamstring strains and concussions.^6,7

With shoulder and elbow injuries in pitchers representing the greatest proportion of DL assignments in recent years, a large body of literature on these injuries, particularly medial ulnar collateral ligament (MUCL) injuries, has been published.^8-13 Since the initial description of MUCL reconstruction, or “Tommy John surgery,” by Dr. Frank Jobe in 1986, much has been done to improve the technique and rehabilitation to maximize player performance following surgery.^10,14-16 Despite this increased attention, large-scale epidemiologic reporting of MUCL injuries in MLB is lacking, but such a report is desirable. The purpose of this work is to: 1) provide a large-scale analysis of injuries occurring in MLB baseball over the course of 18 seasons (1998-2015); 2) highlight the financial implications of these injuries; and 3) detail the evolution of MUCL injuries and reconstructive surgery since it was first performed on a MLB pitcher in 1974. Our study represents the largest longitudinal analysis of MLB injuries since the league expanded to its current level of 30 teams in 1998. It is our hope that this work will serve as a framework for future study of the most common and highest impact injuries occurring in baseball.

Materials And Methods

We performed a retrospective review of the MLB DL from 1998 to 2015. Data analyzed included player demographics such as club, year of placement, age, and position. Injury-specific variables included date of placement on DL, length of time on DL, date of reinstatement, body part injured, diagnosis, and cost of replacement. If a player was put on the DL multiple times during a season, each placement was viewed as a different injury, even if it was to the same body part. If a player was put on the DL for injuries to multiple body parts, the primary injury was analyzed.

Disabled List Data

Although the DL has existed since 1916, this current study covers 18 seasons from 1998 to 2015. The 1998 season was chosen as a starting point because this is the year when MLB expanded to 30 teams. Since then, the number of teams and the active roster limits (25 players) have remained constant, allowing for reliable comparisons across seasons. Initially designed as a roster management tool to allow injured players to temporarily be replaced with healthy players, the DL was not created as an injury database. However, the rules and regulations of the DL have remained fairly constant over the last 18 years, allowing reasonable comparisons of injury data and trends across this timespan. In order for a player to be assigned to the DL, the nature and extent of injury must be certified by a physician. Once designated for the DL, a player cannot return to the major league team for a minimum of 15 days. If the injury is severe, the player can remain on the DL for the remainder of the season or until he is deemed healthy enough to return to play by a physician. One notable exception is the treatment of concussions. Since 2011, a player diagnosed with a concussion may be placed on the DL for a minimum of 7 days rather than 15. The introduction of the HITS database in 2010 should allow for more detailed and reliable study of injuries in baseball moving forward. Although it contains robust data for every injury that has occurred in MLB and MiLB over the last 5 seasons, it does not allow for epidemiologic and longitudinal study of injury patterns and trends in baseball prior to 2010.

 

Cost of Placing Players on the DL

The dollars lost were calculated by prorating the injured player’s daily salary and multiplying by the number of days missed on the DL. For example, if a player’s annual salary is $1,820,000, his daily salary for the 182 day season is $10,000. If assigned to the DL for 15 days, $150,000 is paid to that player while he is inactive and unable to play. An additional cost is the salary of the replacement player who fills the roster spot. For this work, the replacement player’s prorated, daily salary was assumed to be the league minimum for that specific year. For example, if the league minimum for a given season is $182,000, and the season is 182 days long, a replacement player earns a minimum of $1,000 per day while he is on the 25-man active roster. Thus, the dollars paid to the replacement would be $15,000. In this scenario, that brings the team’s total cost to $165,000 ($150,000 plus $15,000). Because the league minimum salary changes year to year, salaries specific to the year of injury were utilized in this analysis.

MUCL Injury Analysis

In order to better understand the evaluation of MUCL injuries over time, all MLB players undergoing MUCL reconstruction (“Tommy John surgery”) were analyzed separately. Similar to prior studies of UCL injuries, these players were identified using DL data, team websites, and publically available internet databases (primarily www.heatmaps.com).^9,12,17-19 Variables studied include the number of procedures, year of surgery, player position, and mean time until return to play at the MLB level. All MLB players undergoing MUCL reconstruction since 1974 (the year the first procedure was performed) were included.

Statistical Methods

Epidemiologic data are reported using descriptive statistics (mean, range, and percentage) where indicated. To determine the significance of trends over time, a best-fit line was generated to illustrate the change over the years. These lines are reported with corresponding R² values. To assess the trend for significance, the slope was compared to a line with a slope of zero (no change over time) using t tests. For all statistical comparisons, the threshold for alpha was set to P < .05.

Results

Between 1998 and 2015, there were 8357 placements of players on the DL, at an average rate of 464 designations per year (Table 1, Figure 1). This resulted in 460,432 days lost to injury, with a mean of 25,186 days out of play per season (Table 1, Figure 2). The mean length of DL assignment per year was 55.1 days per injury, with a low of 49.1 days in 2011 and a high of 59.2 days in 2001 (Table 1, Figure 3). During the study period, the number of players placed on the DL and the total number of DL days steadily increased (P < .001 and P = .003, respectively), while the average length of DL assignments remained steady (P = .647). When analyzing the data by body region injured, the shoulder (20.6%) and elbow (19.6%) were the 2 leading causes of time out of play (Table 2). This was followed distantly by the chest/back/spine (13.7%), wrist/hand/fingers (10.1%), lower leg/knee (9.8%), and the upper leg/thigh (9.5%). Although the percentage of injuries occurring to the upper extremity remained stable, the rate of shoulder injuries steadily decreased (P = .023) as elbow injuries increased (P = .015) (Table 3, Figure 4). This inverse relationship was also demonstrated for the annual number of DL days for shoulder (P = .033) and elbow (P = 0.005) injuries (Figure 5).

 

 

 

 

 

 

 

Regarding the financial impact of these injuries, the mean annual cost of replacing players on the DL was $423,267,633.78 (Table 4). This ranged from a low of $136,397,147 in 1998 to a high of $694,835,359 in 2015. There was a steady increase in the cost of replacement during the study period (P < .001) that coincides with the increasing salaries during that time span (Figure 6). In total, $6,732,167,180 was paid to players assigned to the DL and $886,650,228 was spent to fill their positions. This brings the total cost of DL assignments to $7,618,817,407 for the study period.

 

Looking specifically at MUCL injuries, a total of 400 MUCL reconstructions have been performed on MLB players since the procedure was first developed in 1974. The vast majority of these were performed in pitchers (n = 361, 90.3%) followed by outfielders (n = 16, 4.0%), infielders (n = 14, 3.5%) and catchers (n = 9, 2.3%) (Table 5). The mean time to return to competition at the MLB level was 17.8 months for pitchers, 11.1 months for outfielders, 9.6 months for infielders, and 10.5 months for catchers. The overall mean time to return was 17.1 months. The annual number of MUCL reconstructions continues to rise dramatically (P < .001) (Figure 7). During the first 12 years (1974-1985), a total of 8 (2.0%) MUCL reconstructions were performed on MLB players. In subsequent decades, this number increased to 44 (11.0%) from 1986-1995, 123 (30.8%) from 1996-2005, and 225 (56.3%) from 2006-2015. Of all Tommy John surgeries performed over 42 years, nearly one-third (n = 131, 32.75%) were performed in the last 5 years alone (2011-2015).

 

 

Discussion

To date, a number of studies have been published on injuries in professional baseball. These can primarily be categorized as either studies with a detailed focus on a single injury type or body region^6-13,17,19 or broader reviews that are limited by the relatively short time span covered.^4,5 The purpose of this work was to provide a comprehensive review of injury trends in MLB since the league expanded to 30 teams in 1998 while paying special attention to the financial impact of those injuries. Additionally, we sought to provide an up-to-date review of MUCL injuries and surgeries since the procedure was first developed in 1974. Ultimately, this data demonstrates that injuries continue to rise in MLB and this increase is accompanied by increased expense for teams. Thankfully, the rates of DL assignments for shoulder injuries are on the decline; however, this decrease is countered by a reciprocal increase in elbow injuries. Similarly, the rates of MUCL reconstruction have also risen dramatically in recent years.

The fact that injury rates are on the rise is confirmed by other published reports. This trend was demonstrated in prior analyses of DL data from the 1989 to 1998⁴ and 2002 to 2008 seasons.⁵ These 2 studies represent the only comprehensive reviews of MLB injury trends to date, and each provides valuable information. Both are consistent with the current study findings that pitchers are the most commonly injured players and that shoulder and elbow injuries represent about half of all injuries.^4,5 Similar injury rates and characteristics have been reported at the collegiate²⁰ and minor league levels.²¹ Despite this consistency, this analysis of injuries from 1998 to 2015 is the first to report that DL designations for shoulder injuries are on the decline while designations for elbow injuries continue to rise. Although the exact etiology of this decline in shoulder injuries remains unknown, there are a number of possible explanations. In recent years, increased emphasis has been placed on shoulder rehabilitation, reduction of glenohumeral internal rotation deficits, scapular stabilization, and overall kinetic chain balance and coordination. However, this does not explain why elbow injuries continue to rise annually.

With this increase in injuries, the cost of maintaining an active 25-man roster is also climbing. As expected, this growing expense is primarily due to the increased number of DL days each year as well as the increase in league salaries. Fortunately, this increased financial strain has been met with steadily increased annual revenues in professional baseball. In 2014, the prorated salary cost to players designated to the DL and their replacements was $579,568,059. This figure represents an estimated 6.4% of the $9 billion in total revenue for MLB that same year.²² Although this may represent a small percentage of the whole, it still embodies an exceptionally large financial responsibility. This does not include the medical expenses incurred to treat and rehabilitate the players’ injuries.

Every injury that occurs in MLB players has the potential to adversely affect players, teams, and MLB as a whole. With its increasing prevalence, need for surgical treatment, and prolonged return to play, injuries to the MUCL of the elbow may represent the most costly of all injuries. Although a multitude of reports on MUCL injuries, treatments, techniques, rehabilitation, and outcomes have been reported,^{8,9,12,14-19,23-25} to our knowledge, a comprehensive and longitudinal incidence study in MLB players has not yet been published. By including every MUCL reconstruction that has been performed on a MLB player, our study demonstrates the dramatic increase in the annual incidence of MUCL surgeries. Studies performed over shorter time intervals corroborate these findings. A recent review of a privately insured patient database revealed an annual increase in MUCL reconstructions of 4.2% in that cohort.²⁶ When looking specifically at the MLB, a recent survey of all 30 clubs found that 25% (96 of 382) of MLB pitchers and 15% (341 of 2324) of minor league pitchers have undergone MUCL reconstruction.⁸ Because it occurs so frequently and requires a mean of 17 months to return to sport, MUCL injuries represent a very significant cause of time out of play.

While this study represents a unique epidemiologic report on injuries in baseball, it is certainly not without its limitations. As stated previously, it relies on DL data that was initially intended to serve as a roster management tool rather than an injury database. Accordingly, detailed and specific information about every injury is not always available. The limitations of DL data will largely be overcome in future studies thanks to the implementation of the HITS database in 2010. Moving forward, this system will allow for more detailed analysis of injury patterns, characteristics, time out of play, treatments rendered, etc. Its main limitation is that the earliest data dates back to 2010, making it less applicable for longitudinal studies like the present one. Another limitation of this study is the estimations used for the cost of replacing players designated to the DL. For each injury, it was assumed that the replacement player was paid a prorated portion of the league minimum salary while on the major league roster, but in some instances, that may not have been the case. It is possible that some players filling roster spots were already under contract for amounts higher than the league minimum. Since that player would be making that amount regardless of the level of play, the team may not have paid them any additional salary while filling the position of the injured player. The strengths of this study are its comprehensive nature and inclusion of 18 years of data, making it the longest such study of injuries in MLB. It also represents the first report of cost of replacement for players designated to the DL. To our knowledge, this study also represents the first comprehensive report of every MUCL surgery that has been performed on MLB players.

 

Conclusion

Injury rates continue to rise in MLB, and upper extremity injuries continue to represent approximately half of all injuries resulting in time out of play. Although shoulder injuries have been on the decline in recent years, this decline is offset by a steady increase in elbow injuries. Each year, MLB players are designated to the DL an average of 464 times for a total of 25,579.6 days. This results in a mean annual cost of over $400 million dollars to replace players lost to injury. Looking specifically at MUCL injuries, a total of 400 MUCL reconstructions have been performed in the MLB since 1974, and nearly one-third of these were performed in the last 5 years. Pitchers represent 90.3% of players requiring MUCL surgery, and the average time to return to sport for all players is 17 months. These data may serve as a foundation for identifying appropriate targets for continued study into the etiologies, strategies for prevention, and optimal treatments of injuries commonly affecting professional baseball players.

While the exact origins of the game of baseball are commonly debated, one thing is certain: statistics have been an integral part of the game since its existence.^1-3 This is true at nearly every level of baseball, especially in Major League Baseball (MLB). As our knowledge and technical capabilities advance, new statistical measures of baseball performance are added at a rapid pace.^1,3 One example is the Pitch f/x video tracking system (Sportvision, Inc.), which now analyzes over 60 variables on each of the estimated 660,000 pitches thrown in the MLB annually. In addition to measuring performance and production, these advancements are being leveraged to better understand the epidemiology and impact of injuries in MLB players.^4,5 As with any sport, performance at the most elite level is highly dependent upon player health and functional capacity. Accordingly, player injuries can have a profound impact not only on individual performance but also on the success of the team as a whole.

The first epidemiologic study of injuries in professional baseball was published by Conte and colleagues⁴ in 2001. This work utilized publically available disabled list (DL) data to perform a comprehensive review of injury patterns in MLB from 1989 to 1999. They demonstrated that injuries were on the rise and that pitchers were more commonly injured (48.4% of all DL reports) and had greater time out of play compared to players of other positions.⁴ Shoulder and elbow injuries were responsible for 49.8% of all DL assignments, distantly followed by knee (7.3%), wrist/hand (6.1%), and back (5.0%).⁴ In a later study, Posner and colleagues⁵ analyzed DL data spanning the 2002 to 2008 seasons. Similarly, they found that injuries continued to increase, and over half (51.2%) of DL assignments occurred secondary to upper extremity injuries.⁵ Although the DL is primarily designed as a roster management tool rather than an injury database, it has provided valuable epidemiologic injury information through the years. Out of concern for player health and well-being, MLB and the MLB Players Association (MLBPA) worked together to create and implement an electronic medical record and Health and Injury Tracking System (HITS) for all MLB and Minor League Baseball (MiLB) players. Now active for over 5 seasons, this database has provided valuable, detailed reports regarding specific injuries occurring in professional baseball, such as hamstring strains and concussions.^6,7

With shoulder and elbow injuries in pitchers representing the greatest proportion of DL assignments in recent years, a large body of literature on these injuries, particularly medial ulnar collateral ligament (MUCL) injuries, has been published.^8-13 Since the initial description of MUCL reconstruction, or “Tommy John surgery,” by Dr. Frank Jobe in 1986, much has been done to improve the technique and rehabilitation to maximize player performance following surgery.^10,14-16 Despite this increased attention, large-scale epidemiologic reporting of MUCL injuries in MLB is lacking, but such a report is desirable. The purpose of this work is to: 1) provide a large-scale analysis of injuries occurring in MLB baseball over the course of 18 seasons (1998-2015); 2) highlight the financial implications of these injuries; and 3) detail the evolution of MUCL injuries and reconstructive surgery since it was first performed on a MLB pitcher in 1974. Our study represents the largest longitudinal analysis of MLB injuries since the league expanded to its current level of 30 teams in 1998. It is our hope that this work will serve as a framework for future study of the most common and highest impact injuries occurring in baseball.

Materials And Methods

We performed a retrospective review of the MLB DL from 1998 to 2015. Data analyzed included player demographics such as club, year of placement, age, and position. Injury-specific variables included date of placement on DL, length of time on DL, date of reinstatement, body part injured, diagnosis, and cost of replacement. If a player was put on the DL multiple times during a season, each placement was viewed as a different injury, even if it was to the same body part. If a player was put on the DL for injuries to multiple body parts, the primary injury was analyzed.

Disabled List Data

Although the DL has existed since 1916, this current study covers 18 seasons from 1998 to 2015. The 1998 season was chosen as a starting point because this is the year when MLB expanded to 30 teams. Since then, the number of teams and the active roster limits (25 players) have remained constant, allowing for reliable comparisons across seasons. Initially designed as a roster management tool to allow injured players to temporarily be replaced with healthy players, the DL was not created as an injury database. However, the rules and regulations of the DL have remained fairly constant over the last 18 years, allowing reasonable comparisons of injury data and trends across this timespan. In order for a player to be assigned to the DL, the nature and extent of injury must be certified by a physician. Once designated for the DL, a player cannot return to the major league team for a minimum of 15 days. If the injury is severe, the player can remain on the DL for the remainder of the season or until he is deemed healthy enough to return to play by a physician. One notable exception is the treatment of concussions. Since 2011, a player diagnosed with a concussion may be placed on the DL for a minimum of 7 days rather than 15. The introduction of the HITS database in 2010 should allow for more detailed and reliable study of injuries in baseball moving forward. Although it contains robust data for every injury that has occurred in MLB and MiLB over the last 5 seasons, it does not allow for epidemiologic and longitudinal study of injury patterns and trends in baseball prior to 2010.

 

Cost of Placing Players on the DL

The dollars lost were calculated by prorating the injured player’s daily salary and multiplying by the number of days missed on the DL. For example, if a player’s annual salary is $1,820,000, his daily salary for the 182 day season is $10,000. If assigned to the DL for 15 days, $150,000 is paid to that player while he is inactive and unable to play. An additional cost is the salary of the replacement player who fills the roster spot. For this work, the replacement player’s prorated, daily salary was assumed to be the league minimum for that specific year. For example, if the league minimum for a given season is $182,000, and the season is 182 days long, a replacement player earns a minimum of $1,000 per day while he is on the 25-man active roster. Thus, the dollars paid to the replacement would be $15,000. In this scenario, that brings the team’s total cost to $165,000 ($150,000 plus $15,000). Because the league minimum salary changes year to year, salaries specific to the year of injury were utilized in this analysis.

MUCL Injury Analysis

In order to better understand the evaluation of MUCL injuries over time, all MLB players undergoing MUCL reconstruction (“Tommy John surgery”) were analyzed separately. Similar to prior studies of UCL injuries, these players were identified using DL data, team websites, and publically available internet databases (primarily www.heatmaps.com).^9,12,17-19 Variables studied include the number of procedures, year of surgery, player position, and mean time until return to play at the MLB level. All MLB players undergoing MUCL reconstruction since 1974 (the year the first procedure was performed) were included.

Statistical Methods

Epidemiologic data are reported using descriptive statistics (mean, range, and percentage) where indicated. To determine the significance of trends over time, a best-fit line was generated to illustrate the change over the years. These lines are reported with corresponding R² values. To assess the trend for significance, the slope was compared to a line with a slope of zero (no change over time) using t tests. For all statistical comparisons, the threshold for alpha was set to P < .05.

Results

Between 1998 and 2015, there were 8357 placements of players on the DL, at an average rate of 464 designations per year (Table 1, Figure 1). This resulted in 460,432 days lost to injury, with a mean of 25,186 days out of play per season (Table 1, Figure 2). The mean length of DL assignment per year was 55.1 days per injury, with a low of 49.1 days in 2011 and a high of 59.2 days in 2001 (Table 1, Figure 3). During the study period, the number of players placed on the DL and the total number of DL days steadily increased (P < .001 and P = .003, respectively), while the average length of DL assignments remained steady (P = .647). When analyzing the data by body region injured, the shoulder (20.6%) and elbow (19.6%) were the 2 leading causes of time out of play (Table 2). This was followed distantly by the chest/back/spine (13.7%), wrist/hand/fingers (10.1%), lower leg/knee (9.8%), and the upper leg/thigh (9.5%). Although the percentage of injuries occurring to the upper extremity remained stable, the rate of shoulder injuries steadily decreased (P = .023) as elbow injuries increased (P = .015) (Table 3, Figure 4). This inverse relationship was also demonstrated for the annual number of DL days for shoulder (P = .033) and elbow (P = 0.005) injuries (Figure 5).

 

 

 

 

 

 

 

Regarding the financial impact of these injuries, the mean annual cost of replacing players on the DL was $423,267,633.78 (Table 4). This ranged from a low of $136,397,147 in 1998 to a high of $694,835,359 in 2015. There was a steady increase in the cost of replacement during the study period (P < .001) that coincides with the increasing salaries during that time span (Figure 6). In total, $6,732,167,180 was paid to players assigned to the DL and $886,650,228 was spent to fill their positions. This brings the total cost of DL assignments to $7,618,817,407 for the study period.

 

Looking specifically at MUCL injuries, a total of 400 MUCL reconstructions have been performed on MLB players since the procedure was first developed in 1974. The vast majority of these were performed in pitchers (n = 361, 90.3%) followed by outfielders (n = 16, 4.0%), infielders (n = 14, 3.5%) and catchers (n = 9, 2.3%) (Table 5). The mean time to return to competition at the MLB level was 17.8 months for pitchers, 11.1 months for outfielders, 9.6 months for infielders, and 10.5 months for catchers. The overall mean time to return was 17.1 months. The annual number of MUCL reconstructions continues to rise dramatically (P < .001) (Figure 7). During the first 12 years (1974-1985), a total of 8 (2.0%) MUCL reconstructions were performed on MLB players. In subsequent decades, this number increased to 44 (11.0%) from 1986-1995, 123 (30.8%) from 1996-2005, and 225 (56.3%) from 2006-2015. Of all Tommy John surgeries performed over 42 years, nearly one-third (n = 131, 32.75%) were performed in the last 5 years alone (2011-2015).

 

 

Discussion

To date, a number of studies have been published on injuries in professional baseball. These can primarily be categorized as either studies with a detailed focus on a single injury type or body region^6-13,17,19 or broader reviews that are limited by the relatively short time span covered.^4,5 The purpose of this work was to provide a comprehensive review of injury trends in MLB since the league expanded to 30 teams in 1998 while paying special attention to the financial impact of those injuries. Additionally, we sought to provide an up-to-date review of MUCL injuries and surgeries since the procedure was first developed in 1974. Ultimately, this data demonstrates that injuries continue to rise in MLB and this increase is accompanied by increased expense for teams. Thankfully, the rates of DL assignments for shoulder injuries are on the decline; however, this decrease is countered by a reciprocal increase in elbow injuries. Similarly, the rates of MUCL reconstruction have also risen dramatically in recent years.

The fact that injury rates are on the rise is confirmed by other published reports. This trend was demonstrated in prior analyses of DL data from the 1989 to 1998⁴ and 2002 to 2008 seasons.⁵ These 2 studies represent the only comprehensive reviews of MLB injury trends to date, and each provides valuable information. Both are consistent with the current study findings that pitchers are the most commonly injured players and that shoulder and elbow injuries represent about half of all injuries.^4,5 Similar injury rates and characteristics have been reported at the collegiate²⁰ and minor league levels.²¹ Despite this consistency, this analysis of injuries from 1998 to 2015 is the first to report that DL designations for shoulder injuries are on the decline while designations for elbow injuries continue to rise. Although the exact etiology of this decline in shoulder injuries remains unknown, there are a number of possible explanations. In recent years, increased emphasis has been placed on shoulder rehabilitation, reduction of glenohumeral internal rotation deficits, scapular stabilization, and overall kinetic chain balance and coordination. However, this does not explain why elbow injuries continue to rise annually.

With this increase in injuries, the cost of maintaining an active 25-man roster is also climbing. As expected, this growing expense is primarily due to the increased number of DL days each year as well as the increase in league salaries. Fortunately, this increased financial strain has been met with steadily increased annual revenues in professional baseball. In 2014, the prorated salary cost to players designated to the DL and their replacements was $579,568,059. This figure represents an estimated 6.4% of the $9 billion in total revenue for MLB that same year.²² Although this may represent a small percentage of the whole, it still embodies an exceptionally large financial responsibility. This does not include the medical expenses incurred to treat and rehabilitate the players’ injuries.

Every injury that occurs in MLB players has the potential to adversely affect players, teams, and MLB as a whole. With its increasing prevalence, need for surgical treatment, and prolonged return to play, injuries to the MUCL of the elbow may represent the most costly of all injuries. Although a multitude of reports on MUCL injuries, treatments, techniques, rehabilitation, and outcomes have been reported,^{8,9,12,14-19,23-25} to our knowledge, a comprehensive and longitudinal incidence study in MLB players has not yet been published. By including every MUCL reconstruction that has been performed on a MLB player, our study demonstrates the dramatic increase in the annual incidence of MUCL surgeries. Studies performed over shorter time intervals corroborate these findings. A recent review of a privately insured patient database revealed an annual increase in MUCL reconstructions of 4.2% in that cohort.²⁶ When looking specifically at the MLB, a recent survey of all 30 clubs found that 25% (96 of 382) of MLB pitchers and 15% (341 of 2324) of minor league pitchers have undergone MUCL reconstruction.⁸ Because it occurs so frequently and requires a mean of 17 months to return to sport, MUCL injuries represent a very significant cause of time out of play.

While this study represents a unique epidemiologic report on injuries in baseball, it is certainly not without its limitations. As stated previously, it relies on DL data that was initially intended to serve as a roster management tool rather than an injury database. Accordingly, detailed and specific information about every injury is not always available. The limitations of DL data will largely be overcome in future studies thanks to the implementation of the HITS database in 2010. Moving forward, this system will allow for more detailed analysis of injury patterns, characteristics, time out of play, treatments rendered, etc. Its main limitation is that the earliest data dates back to 2010, making it less applicable for longitudinal studies like the present one. Another limitation of this study is the estimations used for the cost of replacing players designated to the DL. For each injury, it was assumed that the replacement player was paid a prorated portion of the league minimum salary while on the major league roster, but in some instances, that may not have been the case. It is possible that some players filling roster spots were already under contract for amounts higher than the league minimum. Since that player would be making that amount regardless of the level of play, the team may not have paid them any additional salary while filling the position of the injured player. The strengths of this study are its comprehensive nature and inclusion of 18 years of data, making it the longest such study of injuries in MLB. It also represents the first report of cost of replacement for players designated to the DL. To our knowledge, this study also represents the first comprehensive report of every MUCL surgery that has been performed on MLB players.

 

Conclusion

Injury rates continue to rise in MLB, and upper extremity injuries continue to represent approximately half of all injuries resulting in time out of play. Although shoulder injuries have been on the decline in recent years, this decline is offset by a steady increase in elbow injuries. Each year, MLB players are designated to the DL an average of 464 times for a total of 25,579.6 days. This results in a mean annual cost of over $400 million dollars to replace players lost to injury. Looking specifically at MUCL injuries, a total of 400 MUCL reconstructions have been performed in the MLB since 1974, and nearly one-third of these were performed in the last 5 years. Pitchers represent 90.3% of players requiring MUCL surgery, and the average time to return to sport for all players is 17 months. These data may serve as a foundation for identifying appropriate targets for continued study into the etiologies, strategies for prevention, and optimal treatments of injuries commonly affecting professional baseball players.

While the exact origins of the game of baseball are commonly debated, one thing is certain: statistics have been an integral part of the game since its existence.^1-3 This is true at nearly every level of baseball, especially in Major League Baseball (MLB). As our knowledge and technical capabilities advance, new statistical measures of baseball performance are added at a rapid pace.^1,3 One example is the Pitch f/x video tracking system (Sportvision, Inc.), which now analyzes over 60 variables on each of the estimated 660,000 pitches thrown in the MLB annually. In addition to measuring performance and production, these advancements are being leveraged to better understand the epidemiology and impact of injuries in MLB players.^4,5 As with any sport, performance at the most elite level is highly dependent upon player health and functional capacity. Accordingly, player injuries can have a profound impact not only on individual performance but also on the success of the team as a whole.

The first epidemiologic study of injuries in professional baseball was published by Conte and colleagues⁴ in 2001. This work utilized publically available disabled list (DL) data to perform a comprehensive review of injury patterns in MLB from 1989 to 1999. They demonstrated that injuries were on the rise and that pitchers were more commonly injured (48.4% of all DL reports) and had greater time out of play compared to players of other positions.⁴ Shoulder and elbow injuries were responsible for 49.8% of all DL assignments, distantly followed by knee (7.3%), wrist/hand (6.1%), and back (5.0%).⁴ In a later study, Posner and colleagues⁵ analyzed DL data spanning the 2002 to 2008 seasons. Similarly, they found that injuries continued to increase, and over half (51.2%) of DL assignments occurred secondary to upper extremity injuries.⁵ Although the DL is primarily designed as a roster management tool rather than an injury database, it has provided valuable epidemiologic injury information through the years. Out of concern for player health and well-being, MLB and the MLB Players Association (MLBPA) worked together to create and implement an electronic medical record and Health and Injury Tracking System (HITS) for all MLB and Minor League Baseball (MiLB) players. Now active for over 5 seasons, this database has provided valuable, detailed reports regarding specific injuries occurring in professional baseball, such as hamstring strains and concussions.^6,7

With shoulder and elbow injuries in pitchers representing the greatest proportion of DL assignments in recent years, a large body of literature on these injuries, particularly medial ulnar collateral ligament (MUCL) injuries, has been published.^8-13 Since the initial description of MUCL reconstruction, or “Tommy John surgery,” by Dr. Frank Jobe in 1986, much has been done to improve the technique and rehabilitation to maximize player performance following surgery.^10,14-16 Despite this increased attention, large-scale epidemiologic reporting of MUCL injuries in MLB is lacking, but such a report is desirable. The purpose of this work is to: 1) provide a large-scale analysis of injuries occurring in MLB baseball over the course of 18 seasons (1998-2015); 2) highlight the financial implications of these injuries; and 3) detail the evolution of MUCL injuries and reconstructive surgery since it was first performed on a MLB pitcher in 1974. Our study represents the largest longitudinal analysis of MLB injuries since the league expanded to its current level of 30 teams in 1998. It is our hope that this work will serve as a framework for future study of the most common and highest impact injuries occurring in baseball.

Materials And Methods

We performed a retrospective review of the MLB DL from 1998 to 2015. Data analyzed included player demographics such as club, year of placement, age, and position. Injury-specific variables included date of placement on DL, length of time on DL, date of reinstatement, body part injured, diagnosis, and cost of replacement. If a player was put on the DL multiple times during a season, each placement was viewed as a different injury, even if it was to the same body part. If a player was put on the DL for injuries to multiple body parts, the primary injury was analyzed.

Disabled List Data

Although the DL has existed since 1916, this current study covers 18 seasons from 1998 to 2015. The 1998 season was chosen as a starting point because this is the year when MLB expanded to 30 teams. Since then, the number of teams and the active roster limits (25 players) have remained constant, allowing for reliable comparisons across seasons. Initially designed as a roster management tool to allow injured players to temporarily be replaced with healthy players, the DL was not created as an injury database. However, the rules and regulations of the DL have remained fairly constant over the last 18 years, allowing reasonable comparisons of injury data and trends across this timespan. In order for a player to be assigned to the DL, the nature and extent of injury must be certified by a physician. Once designated for the DL, a player cannot return to the major league team for a minimum of 15 days. If the injury is severe, the player can remain on the DL for the remainder of the season or until he is deemed healthy enough to return to play by a physician. One notable exception is the treatment of concussions. Since 2011, a player diagnosed with a concussion may be placed on the DL for a minimum of 7 days rather than 15. The introduction of the HITS database in 2010 should allow for more detailed and reliable study of injuries in baseball moving forward. Although it contains robust data for every injury that has occurred in MLB and MiLB over the last 5 seasons, it does not allow for epidemiologic and longitudinal study of injury patterns and trends in baseball prior to 2010.

 

Cost of Placing Players on the DL

The dollars lost were calculated by prorating the injured player’s daily salary and multiplying by the number of days missed on the DL. For example, if a player’s annual salary is $1,820,000, his daily salary for the 182 day season is $10,000. If assigned to the DL for 15 days, $150,000 is paid to that player while he is inactive and unable to play. An additional cost is the salary of the replacement player who fills the roster spot. For this work, the replacement player’s prorated, daily salary was assumed to be the league minimum for that specific year. For example, if the league minimum for a given season is $182,000, and the season is 182 days long, a replacement player earns a minimum of $1,000 per day while he is on the 25-man active roster. Thus, the dollars paid to the replacement would be $15,000. In this scenario, that brings the team’s total cost to $165,000 ($150,000 plus $15,000). Because the league minimum salary changes year to year, salaries specific to the year of injury were utilized in this analysis.

MUCL Injury Analysis

In order to better understand the evaluation of MUCL injuries over time, all MLB players undergoing MUCL reconstruction (“Tommy John surgery”) were analyzed separately. Similar to prior studies of UCL injuries, these players were identified using DL data, team websites, and publically available internet databases (primarily www.heatmaps.com).^9,12,17-19 Variables studied include the number of procedures, year of surgery, player position, and mean time until return to play at the MLB level. All MLB players undergoing MUCL reconstruction since 1974 (the year the first procedure was performed) were included.

Statistical Methods

Epidemiologic data are reported using descriptive statistics (mean, range, and percentage) where indicated. To determine the significance of trends over time, a best-fit line was generated to illustrate the change over the years. These lines are reported with corresponding R² values. To assess the trend for significance, the slope was compared to a line with a slope of zero (no change over time) using t tests. For all statistical comparisons, the threshold for alpha was set to P < .05.

Results

Between 1998 and 2015, there were 8357 placements of players on the DL, at an average rate of 464 designations per year (Table 1, Figure 1). This resulted in 460,432 days lost to injury, with a mean of 25,186 days out of play per season (Table 1, Figure 2). The mean length of DL assignment per year was 55.1 days per injury, with a low of 49.1 days in 2011 and a high of 59.2 days in 2001 (Table 1, Figure 3). During the study period, the number of players placed on the DL and the total number of DL days steadily increased (P < .001 and P = .003, respectively), while the average length of DL assignments remained steady (P = .647). When analyzing the data by body region injured, the shoulder (20.6%) and elbow (19.6%) were the 2 leading causes of time out of play (Table 2). This was followed distantly by the chest/back/spine (13.7%), wrist/hand/fingers (10.1%), lower leg/knee (9.8%), and the upper leg/thigh (9.5%). Although the percentage of injuries occurring to the upper extremity remained stable, the rate of shoulder injuries steadily decreased (P = .023) as elbow injuries increased (P = .015) (Table 3, Figure 4). This inverse relationship was also demonstrated for the annual number of DL days for shoulder (P = .033) and elbow (P = 0.005) injuries (Figure 5).

 

 

 

 

 

 

 

Regarding the financial impact of these injuries, the mean annual cost of replacing players on the DL was $423,267,633.78 (Table 4). This ranged from a low of $136,397,147 in 1998 to a high of $694,835,359 in 2015. There was a steady increase in the cost of replacement during the study period (P < .001) that coincides with the increasing salaries during that time span (Figure 6). In total, $6,732,167,180 was paid to players assigned to the DL and $886,650,228 was spent to fill their positions. This brings the total cost of DL assignments to $7,618,817,407 for the study period.

 

Looking specifically at MUCL injuries, a total of 400 MUCL reconstructions have been performed on MLB players since the procedure was first developed in 1974. The vast majority of these were performed in pitchers (n = 361, 90.3%) followed by outfielders (n = 16, 4.0%), infielders (n = 14, 3.5%) and catchers (n = 9, 2.3%) (Table 5). The mean time to return to competition at the MLB level was 17.8 months for pitchers, 11.1 months for outfielders, 9.6 months for infielders, and 10.5 months for catchers. The overall mean time to return was 17.1 months. The annual number of MUCL reconstructions continues to rise dramatically (P < .001) (Figure 7). During the first 12 years (1974-1985), a total of 8 (2.0%) MUCL reconstructions were performed on MLB players. In subsequent decades, this number increased to 44 (11.0%) from 1986-1995, 123 (30.8%) from 1996-2005, and 225 (56.3%) from 2006-2015. Of all Tommy John surgeries performed over 42 years, nearly one-third (n = 131, 32.75%) were performed in the last 5 years alone (2011-2015).

 

 

Discussion

To date, a number of studies have been published on injuries in professional baseball. These can primarily be categorized as either studies with a detailed focus on a single injury type or body region^6-13,17,19 or broader reviews that are limited by the relatively short time span covered.^4,5 The purpose of this work was to provide a comprehensive review of injury trends in MLB since the league expanded to 30 teams in 1998 while paying special attention to the financial impact of those injuries. Additionally, we sought to provide an up-to-date review of MUCL injuries and surgeries since the procedure was first developed in 1974. Ultimately, this data demonstrates that injuries continue to rise in MLB and this increase is accompanied by increased expense for teams. Thankfully, the rates of DL assignments for shoulder injuries are on the decline; however, this decrease is countered by a reciprocal increase in elbow injuries. Similarly, the rates of MUCL reconstruction have also risen dramatically in recent years.

The fact that injury rates are on the rise is confirmed by other published reports. This trend was demonstrated in prior analyses of DL data from the 1989 to 1998⁴ and 2002 to 2008 seasons.⁵ These 2 studies represent the only comprehensive reviews of MLB injury trends to date, and each provides valuable information. Both are consistent with the current study findings that pitchers are the most commonly injured players and that shoulder and elbow injuries represent about half of all injuries.^4,5 Similar injury rates and characteristics have been reported at the collegiate²⁰ and minor league levels.²¹ Despite this consistency, this analysis of injuries from 1998 to 2015 is the first to report that DL designations for shoulder injuries are on the decline while designations for elbow injuries continue to rise. Although the exact etiology of this decline in shoulder injuries remains unknown, there are a number of possible explanations. In recent years, increased emphasis has been placed on shoulder rehabilitation, reduction of glenohumeral internal rotation deficits, scapular stabilization, and overall kinetic chain balance and coordination. However, this does not explain why elbow injuries continue to rise annually.

With this increase in injuries, the cost of maintaining an active 25-man roster is also climbing. As expected, this growing expense is primarily due to the increased number of DL days each year as well as the increase in league salaries. Fortunately, this increased financial strain has been met with steadily increased annual revenues in professional baseball. In 2014, the prorated salary cost to players designated to the DL and their replacements was $579,568,059. This figure represents an estimated 6.4% of the $9 billion in total revenue for MLB that same year.²² Although this may represent a small percentage of the whole, it still embodies an exceptionally large financial responsibility. This does not include the medical expenses incurred to treat and rehabilitate the players’ injuries.

Every injury that occurs in MLB players has the potential to adversely affect players, teams, and MLB as a whole. With its increasing prevalence, need for surgical treatment, and prolonged return to play, injuries to the MUCL of the elbow may represent the most costly of all injuries. Although a multitude of reports on MUCL injuries, treatments, techniques, rehabilitation, and outcomes have been reported,^{8,9,12,14-19,23-25} to our knowledge, a comprehensive and longitudinal incidence study in MLB players has not yet been published. By including every MUCL reconstruction that has been performed on a MLB player, our study demonstrates the dramatic increase in the annual incidence of MUCL surgeries. Studies performed over shorter time intervals corroborate these findings. A recent review of a privately insured patient database revealed an annual increase in MUCL reconstructions of 4.2% in that cohort.²⁶ When looking specifically at the MLB, a recent survey of all 30 clubs found that 25% (96 of 382) of MLB pitchers and 15% (341 of 2324) of minor league pitchers have undergone MUCL reconstruction.⁸ Because it occurs so frequently and requires a mean of 17 months to return to sport, MUCL injuries represent a very significant cause of time out of play.

While this study represents a unique epidemiologic report on injuries in baseball, it is certainly not without its limitations. As stated previously, it relies on DL data that was initially intended to serve as a roster management tool rather than an injury database. Accordingly, detailed and specific information about every injury is not always available. The limitations of DL data will largely be overcome in future studies thanks to the implementation of the HITS database in 2010. Moving forward, this system will allow for more detailed analysis of injury patterns, characteristics, time out of play, treatments rendered, etc. Its main limitation is that the earliest data dates back to 2010, making it less applicable for longitudinal studies like the present one. Another limitation of this study is the estimations used for the cost of replacing players designated to the DL. For each injury, it was assumed that the replacement player was paid a prorated portion of the league minimum salary while on the major league roster, but in some instances, that may not have been the case. It is possible that some players filling roster spots were already under contract for amounts higher than the league minimum. Since that player would be making that amount regardless of the level of play, the team may not have paid them any additional salary while filling the position of the injured player. The strengths of this study are its comprehensive nature and inclusion of 18 years of data, making it the longest such study of injuries in MLB. It also represents the first report of cost of replacement for players designated to the DL. To our knowledge, this study also represents the first comprehensive report of every MUCL surgery that has been performed on MLB players.

 

Conclusion

Injury rates continue to rise in MLB, and upper extremity injuries continue to represent approximately half of all injuries resulting in time out of play. Although shoulder injuries have been on the decline in recent years, this decline is offset by a steady increase in elbow injuries. Each year, MLB players are designated to the DL an average of 464 times for a total of 25,579.6 days. This results in a mean annual cost of over $400 million dollars to replace players lost to injury. Looking specifically at MUCL injuries, a total of 400 MUCL reconstructions have been performed in the MLB since 1974, and nearly one-third of these were performed in the last 5 years. Pitchers represent 90.3% of players requiring MUCL surgery, and the average time to return to sport for all players is 17 months. These data may serve as a foundation for identifying appropriate targets for continued study into the etiologies, strategies for prevention, and optimal treatments of injuries commonly affecting professional baseball players.

Upper extremity injuries are very common in pitchers in amateur and professional baseball. The vast majority involving labral or rotator cuff pathology.^1-3 While uncommon, injuries to the latissimus dorsi (LD) (Figure) and teres major (TM) have been reported in Major League Baseball (MLB) pitchers.⁴ Jobe and colleagues⁵ demonstrated the role of the LD during the various phases of pitching. The LD is most active during the acceleration phase and remains active during the deceleration phase and follow-through.⁶ Anatomically, the TM lies posterior to the LD separated by bursal tissue. The tendon fibers converge and unite along their lower borders, leading to a synergistic mechanism of action.

Due to the rarity of LD and TM injuries, literature on the pathology and appropriate treatments for these injuries is limited. The goal of this review is to present the current literature on professional baseball players who have undergone either nonsurgical treatment or surgery for LD and TM strains and/or avulsion injuries. This review will ultimately assist clinicians when deciding on the optimal treatment method for professional baseball players.

Methods

We performed an extensive Medline database search with the following search algorithm: ([latissimus OR latissimus dorsi OR teres major] AND baseball). The search returned 20 citations. Inclusion criteria consisted of clinical studies that focused on professional baseball pitchers with TM and/or LD injuries that underwent either conservative nonsurgical treatment or surgical repair. There was no exclusion based on the type of injury present, such as avulsion vs strain. Any study with amateur athletes or athletes from other sports such as handball or rugby were excluded. Due to the limited amount of data available, the majority of included studies were case reports and case series.

Based on these parameters, 5 articles met criteria for inclusion. Of the 5 included studies, 3 were case reports and 2 were case series. From the eligible articles, the following information was obtained: publication year, sample size, mean age, mean follow-up duration, type of treatment (conservative vs surgical), ability to return to original level of play, time required to return to original form, and complications (Tables 1, 2).

Results

Nonoperative Management

Four of the 5 included studies implemented only conservative therapy for their patients.^4,7-9 The average duration these patients were followed for during treatment and rehabilitation was 26.3 months. Malcolm and colleagues⁷ followed patients for 8 months, the shortest length among the 4 conservative studies in this review. Leland and colleagues8 followed patients for 17 months, and Nagda and colleagues⁹ had the longest length of observation of 36 months (range 12 to 82 months).Schickendantz and colleagues⁴ followed patients for >12 months, but the exact duration was not specified. In order to calculate the average duration of observation, each patient was assigned a duration of 12 months.

Of the 30 patients included in this review, 29 were treated conservatively. All of the included studies consisted of male patients. The mean age was 26.8 years (range 22 to 28.1 years). Of the 29 injuries treated conservatively, there were 2 LD tendon avulsions, 4 TM tendon avulsions, 1 LD and TM tendon avulsion, 7 LD intramuscular strains, 9 TM intramuscular strains, and 6 LD and TM intramuscular strains.

Treatment Protocol

The various treatment and rehabilitation programs used for the conservative patient population all followed a similar pathway. After initial injury, a rest period focused on stretching was implemented. Patients were started on steroid or anti-inflammatory medications, cryotherapy, or other therapeutic modalities. Once pain-free and full range of motion was achieved, patients began the strength and throwing components of the rehabilitation program. Reoccurrence of symptoms would halt the throwing component of the rehabilitation program until symptoms improved. Patients were progressed through a return-to-throw program and once they could throw off the mound and achieve their preinjury velocity, strength, and range of motion, they were cleared to return to competitive pitching.

In the senior author’s (MSS) practice, all throwers are managed with the same nonoperative protocol.⁴ Initial treatment consists of short periods of rest and symptom control via the application of cryotherapy, among other modalities. Restoration of preinjury range of motion is achieved with active-assisted stretching exercises. As range of motion begins approaching pre-injury levels, strength training is initiated with isometric strengthening of the LD and TM progressing to resistance exercises. Exercising the abdominal core, strengthening the lower body, and cardiovascular conditioning are focal points of the rehabilitation period. Once patients regain preinjury shoulder strength and range of motion without pain, they begin a throwing program that consists of 4 weeks of long toss followed by 2 weeks of throwing from the pitching mound. After completion of the throwing program, the patient is allowed to return to competitive pitching. For patients who did not suffer season-ending injury, the average time required to return to play was 99.8 days (range 72.3 to 182.6 days).

 

Complications and Reinjury

The patients in Leland and colleagues⁸ and Malcolm and colleagues⁷ did not suffer any complications or reinjuries. In Schickendantz and colleagues⁴, all but 3 of the 10 patients were able to return to full speed pitching by 3 months. The other 3 required 4, 6, and 10 months. The patient that required 10 months tore both his LD and TM and the patient that required 6 months tore his TM and was never able to regain his pre-injury throwing velocity. None of the TM tears had a recurrence, while 1 LD tear had a recurrence of injury 6 months after returning to competitive pitching. This patient was successfully treated with 6 weeks of conservative rest and rehabilitation.

In Nagda and colleagues⁹, 2 athletes suffered injury recurrence. One athlete with a LD strain suffered 2 subsequent LD strains, 4 months and 1 year after initial injury. The other athlete with a LD avulsion suffered a subsequent TM avulsion 13 months after initial injury. One pitcher who had an LD and TM strain suffered a superior labrum anterior and posterior (SLAP) tear and was never able to return to his prior level of play.

Surgical Treatment

Only 1 of the 5 included studies utilized surgical repair for their patient.¹⁰ The single patient suffered an avulsion injury of the distal LD tendon and its insertion on the humerus. The LD tendon was retracted approximately 5 cm from the distal humeral insertion. The TM was not involved. Eight days post-injury, the patient underwent surgical repair.¹¹ Postoperatively, the patient started passive range of motion after 2 weeks and active range of motion after 6 weeks. He started throwing at 12 weeks and returned to play at 30 weeks after he had returned to his preinjury form in regards to muscle strength, pitch control, and velocity. The patient was able to resume pitching at a high level in MLB.

Discussion

Overhand throwing athletes, especially professional baseball players, have to constantly deal with a variety of shoulder injuries.^12,13 Currently, there is minimal literature on isolated TM and LD injuries. As a result, there is still debate about the optimal treatment method for these injuries, especially in athletes who compete at the highest level. In order to treat isolated injuries of these muscles, it is important to understand their anatomic relationship, as these 2 muscles are intimately associated. The LD originates from the thoracolumbar spine and inserts on the proximal humerus between the pectoralis<hl name="2"/> major and TM tendons. The TM originates from the scapula and, similar to the LD, inserts on the proximal humerus. In an anatomic study, the TM tendon inserted into the LD tendon before its humeral insertion in the majority of cadavers.^14,15

The LD is responsible for extension, adduction, and internal rotation of the humerus. The TM, while not as extensively studied, is believed to also contribute to extension, adduction, and internal rotation of the humerus.¹⁶ As Jobe and colleagues⁵ demonstrated, the LD is vital during the acceleration phase of pitching. While they were unable to make any conclusions about the role of the TM during the pitching cycle, it is reasonable to hypothesize that these 2 muscles work together. While it is thought that these 2 muscles work as a unit, it is significant to note that a professional pitcher can sustain an isolated injury to the TM without injury to the LD, and vice versa. This questions whether these 2 muscles work more independently than once thought. One hypothesis is that the physical size of the LD provides protection from injuries that the smaller TM cannot overcome. This is a potential area of further research.

The most common findings in patients with TM injuries include swelling, bruising, tenderness of the proximal arm, and limitations of shoulder range of motion in abduction, flexion, and external rotation. There is also weakness when resistance is applied against internal rotation and extension. Similar to the TM, common findings in patients with LD injuries include pain in the posterior shoulder, bruising, and weakness when resistance is applied against internal rotation of the shoulder. Pitchers are often able to pinpoint the occurrence of their acute pain during a specific time in the game. They commonly experience a pulling sensation and sometimes even feel a “pop” in their shoulder followed by an acute onset of pain and stiffness in the posterior aspect of the axilla. These injuries seem to be associated with the pitcher throwing a “breaking ball,” a pitch that requires greater shoulder rotation since it changes trajectory while traveling towards home plate. Despite the clear role of the LD and hypothesized role of the TM in the pitching sequence, there has been limited research on the optimal treatment of isolated injuries of these muscles in MLB pitchers. The majority of studies in this review opted for conservative treatment for both LD and TM injuries. The only study that presented a surgical option was for a LD avulsion injury.

 

Athletes undergoing either conservative or surgical treatment required a significant period of recovery and rehabilitation before they were able to compete at the professional level. In Leland and colleagues⁸, it took about 10 to 12 weeks of rehabilitation for both pitchers to return to pitching against competition. In Schickendantz and colleagues⁴, barring any complications or injury recurrence, it took patients 12 weeks to return to their preinjury level. In Malcolm and colleagues⁷, magnetic resonance imaging after 8 weeks showed marked recovery, and shortly after the pitcher was able to return to the pitching rotation. In Nagda and colleagues⁹, the time lost to injury ranged from 7 weeks to an entire season. Of the 9 pitchers who were lost for the season, 6 had avulsion injuries. The other 3 consisted of an LD strain, TM strain, and LD plus TM strain.⁹ In this study, it seems that avulsion injuries had a more significant impact on patient recovery. On average, it took 35.6 days after injury for players to begin throwing. In contrast, it took an average of 65.5 days after an avulsion injury for players to begin throwing. Ellman and colleagues¹⁰ included the only surgically repaired injury, and it was for an avulsion of the LD tendon. In the surgical case, it took slightly longer for the pitcher to return to preinjury form. It took him 12 to 16 weeks to begin light throwing and his full return to pitching took about 20 to 30 weeks. Since muscle strains and tendon avulsions are significantly different injuries in regards to the type of soft tissue damage and healing potential, they may require different treatment strategies. An avulsion injury may require more aggressive intervention, whereas a strain may only require conservative rehabilitation. Ultimately, there does not seem to be a significant benefit of one treatment option compared to the other. The majority of conservatively managed pitchers were able to return to previous form in a reasonable time frame. While each rehabilitation protocol was slightly different, multiple studies advocated for rehab programs that centered around the following goals: slowly progressing pitchers to light throwing once their pain resolved, followed by long throwing, then throwing off of the mound, and finally returning to competitive pitching. It is important to discuss with patients that rehabilitation generally takes 12 to 16 weeks before they are able to fully return to pitching against competition and that rest should immediately follow any recurrence of pain or stiffness. Once those symptoms resolve, patients may continue the rehabilitation protocol.

As with any form of treatment, there are risks involved. This holds true for both conservative and nonconservative therapy for LD and TM injuries. One risk of nonoperative treatment of an LD avulsion is the development of strength deficits in the muscle.¹⁷ While this deficit may go unnoticed in a recreational athlete, it may be more pronounced in a professional athlete, especially since the LD of a professional baseball pitcher is more active on electromyography during the acceleration phase of the pitching cycle compared to a recreational athlete.¹⁸ Another risk of conservative treatment of an LD avulsion is jeopardizing the potential for future surgery. As a result, some advocate for early surgical intervention of an acute LD avulsion.^19,20 Others, however, recommend conservative management with subsequent surgical intervention if conservative measures fail. One caveat is that surgical intervention to restore the original anatomy may become difficult after a certain period of time due to the buildup of scar tissue. Surgical intervention also has associated risks, such as nerve injury, infection, vascular damage, persistent pain, and the buildup of large amounts of scar tissue. It is important to discuss these risks with patients when deciding on a treatment option.

LD and TM avulsion and tears typically present after an acute event in throwing athletes. There are a number of case reports published that demonstrate successful outcomes with both nonoperative management²¹ and operative repair of LD injuries in non-throwing athletes such as competitive water skiers,^22,23 steer wrestlers,²⁴ professional wrestlers,²⁵ and recreational rock climbers.²⁶ The 5 studies included in this review were the first ones to present LD and TM injuries in MLB pitchers. They discussed the outcomes of mainly conservative and surgical management of LD and TM avulsion and tears. Unfortunately, there remains a limited number of cases on the treatment of these injuries in highly competitive throwing athletes. Further research is required to elucidate the advantages and disadvantages of operative vs nonoperative treatment. The goal of this review is to provide clinicians with a concise summary of the current literature so that they may offer some evidence to their patients when discussing appropriate treatment plans.

Upper extremity injuries are very common in pitchers in amateur and professional baseball. The vast majority involving labral or rotator cuff pathology.^1-3 While uncommon, injuries to the latissimus dorsi (LD) (Figure) and teres major (TM) have been reported in Major League Baseball (MLB) pitchers.⁴ Jobe and colleagues⁵ demonstrated the role of the LD during the various phases of pitching. The LD is most active during the acceleration phase and remains active during the deceleration phase and follow-through.⁶ Anatomically, the TM lies posterior to the LD separated by bursal tissue. The tendon fibers converge and unite along their lower borders, leading to a synergistic mechanism of action.

Due to the rarity of LD and TM injuries, literature on the pathology and appropriate treatments for these injuries is limited. The goal of this review is to present the current literature on professional baseball players who have undergone either nonsurgical treatment or surgery for LD and TM strains and/or avulsion injuries. This review will ultimately assist clinicians when deciding on the optimal treatment method for professional baseball players.

Methods

We performed an extensive Medline database search with the following search algorithm: ([latissimus OR latissimus dorsi OR teres major] AND baseball). The search returned 20 citations. Inclusion criteria consisted of clinical studies that focused on professional baseball pitchers with TM and/or LD injuries that underwent either conservative nonsurgical treatment or surgical repair. There was no exclusion based on the type of injury present, such as avulsion vs strain. Any study with amateur athletes or athletes from other sports such as handball or rugby were excluded. Due to the limited amount of data available, the majority of included studies were case reports and case series.

Based on these parameters, 5 articles met criteria for inclusion. Of the 5 included studies, 3 were case reports and 2 were case series. From the eligible articles, the following information was obtained: publication year, sample size, mean age, mean follow-up duration, type of treatment (conservative vs surgical), ability to return to original level of play, time required to return to original form, and complications (Tables 1, 2).

Results

Nonoperative Management

Four of the 5 included studies implemented only conservative therapy for their patients.^4,7-9 The average duration these patients were followed for during treatment and rehabilitation was 26.3 months. Malcolm and colleagues⁷ followed patients for 8 months, the shortest length among the 4 conservative studies in this review. Leland and colleagues8 followed patients for 17 months, and Nagda and colleagues⁹ had the longest length of observation of 36 months (range 12 to 82 months).Schickendantz and colleagues⁴ followed patients for >12 months, but the exact duration was not specified. In order to calculate the average duration of observation, each patient was assigned a duration of 12 months.

Of the 30 patients included in this review, 29 were treated conservatively. All of the included studies consisted of male patients. The mean age was 26.8 years (range 22 to 28.1 years). Of the 29 injuries treated conservatively, there were 2 LD tendon avulsions, 4 TM tendon avulsions, 1 LD and TM tendon avulsion, 7 LD intramuscular strains, 9 TM intramuscular strains, and 6 LD and TM intramuscular strains.

Treatment Protocol

The various treatment and rehabilitation programs used for the conservative patient population all followed a similar pathway. After initial injury, a rest period focused on stretching was implemented. Patients were started on steroid or anti-inflammatory medications, cryotherapy, or other therapeutic modalities. Once pain-free and full range of motion was achieved, patients began the strength and throwing components of the rehabilitation program. Reoccurrence of symptoms would halt the throwing component of the rehabilitation program until symptoms improved. Patients were progressed through a return-to-throw program and once they could throw off the mound and achieve their preinjury velocity, strength, and range of motion, they were cleared to return to competitive pitching.

In the senior author’s (MSS) practice, all throwers are managed with the same nonoperative protocol.⁴ Initial treatment consists of short periods of rest and symptom control via the application of cryotherapy, among other modalities. Restoration of preinjury range of motion is achieved with active-assisted stretching exercises. As range of motion begins approaching pre-injury levels, strength training is initiated with isometric strengthening of the LD and TM progressing to resistance exercises. Exercising the abdominal core, strengthening the lower body, and cardiovascular conditioning are focal points of the rehabilitation period. Once patients regain preinjury shoulder strength and range of motion without pain, they begin a throwing program that consists of 4 weeks of long toss followed by 2 weeks of throwing from the pitching mound. After completion of the throwing program, the patient is allowed to return to competitive pitching. For patients who did not suffer season-ending injury, the average time required to return to play was 99.8 days (range 72.3 to 182.6 days).

 

Complications and Reinjury

The patients in Leland and colleagues⁸ and Malcolm and colleagues⁷ did not suffer any complications or reinjuries. In Schickendantz and colleagues⁴, all but 3 of the 10 patients were able to return to full speed pitching by 3 months. The other 3 required 4, 6, and 10 months. The patient that required 10 months tore both his LD and TM and the patient that required 6 months tore his TM and was never able to regain his pre-injury throwing velocity. None of the TM tears had a recurrence, while 1 LD tear had a recurrence of injury 6 months after returning to competitive pitching. This patient was successfully treated with 6 weeks of conservative rest and rehabilitation.

In Nagda and colleagues⁹, 2 athletes suffered injury recurrence. One athlete with a LD strain suffered 2 subsequent LD strains, 4 months and 1 year after initial injury. The other athlete with a LD avulsion suffered a subsequent TM avulsion 13 months after initial injury. One pitcher who had an LD and TM strain suffered a superior labrum anterior and posterior (SLAP) tear and was never able to return to his prior level of play.

Surgical Treatment

Only 1 of the 5 included studies utilized surgical repair for their patient.¹⁰ The single patient suffered an avulsion injury of the distal LD tendon and its insertion on the humerus. The LD tendon was retracted approximately 5 cm from the distal humeral insertion. The TM was not involved. Eight days post-injury, the patient underwent surgical repair.¹¹ Postoperatively, the patient started passive range of motion after 2 weeks and active range of motion after 6 weeks. He started throwing at 12 weeks and returned to play at 30 weeks after he had returned to his preinjury form in regards to muscle strength, pitch control, and velocity. The patient was able to resume pitching at a high level in MLB.

Discussion

Overhand throwing athletes, especially professional baseball players, have to constantly deal with a variety of shoulder injuries.^12,13 Currently, there is minimal literature on isolated TM and LD injuries. As a result, there is still debate about the optimal treatment method for these injuries, especially in athletes who compete at the highest level. In order to treat isolated injuries of these muscles, it is important to understand their anatomic relationship, as these 2 muscles are intimately associated. The LD originates from the thoracolumbar spine and inserts on the proximal humerus between the pectoralis<hl name="2"/> major and TM tendons. The TM originates from the scapula and, similar to the LD, inserts on the proximal humerus. In an anatomic study, the TM tendon inserted into the LD tendon before its humeral insertion in the majority of cadavers.^14,15

The LD is responsible for extension, adduction, and internal rotation of the humerus. The TM, while not as extensively studied, is believed to also contribute to extension, adduction, and internal rotation of the humerus.¹⁶ As Jobe and colleagues⁵ demonstrated, the LD is vital during the acceleration phase of pitching. While they were unable to make any conclusions about the role of the TM during the pitching cycle, it is reasonable to hypothesize that these 2 muscles work together. While it is thought that these 2 muscles work as a unit, it is significant to note that a professional pitcher can sustain an isolated injury to the TM without injury to the LD, and vice versa. This questions whether these 2 muscles work more independently than once thought. One hypothesis is that the physical size of the LD provides protection from injuries that the smaller TM cannot overcome. This is a potential area of further research.

The most common findings in patients with TM injuries include swelling, bruising, tenderness of the proximal arm, and limitations of shoulder range of motion in abduction, flexion, and external rotation. There is also weakness when resistance is applied against internal rotation and extension. Similar to the TM, common findings in patients with LD injuries include pain in the posterior shoulder, bruising, and weakness when resistance is applied against internal rotation of the shoulder. Pitchers are often able to pinpoint the occurrence of their acute pain during a specific time in the game. They commonly experience a pulling sensation and sometimes even feel a “pop” in their shoulder followed by an acute onset of pain and stiffness in the posterior aspect of the axilla. These injuries seem to be associated with the pitcher throwing a “breaking ball,” a pitch that requires greater shoulder rotation since it changes trajectory while traveling towards home plate. Despite the clear role of the LD and hypothesized role of the TM in the pitching sequence, there has been limited research on the optimal treatment of isolated injuries of these muscles in MLB pitchers. The majority of studies in this review opted for conservative treatment for both LD and TM injuries. The only study that presented a surgical option was for a LD avulsion injury.

 

Athletes undergoing either conservative or surgical treatment required a significant period of recovery and rehabilitation before they were able to compete at the professional level. In Leland and colleagues⁸, it took about 10 to 12 weeks of rehabilitation for both pitchers to return to pitching against competition. In Schickendantz and colleagues⁴, barring any complications or injury recurrence, it took patients 12 weeks to return to their preinjury level. In Malcolm and colleagues⁷, magnetic resonance imaging after 8 weeks showed marked recovery, and shortly after the pitcher was able to return to the pitching rotation. In Nagda and colleagues⁹, the time lost to injury ranged from 7 weeks to an entire season. Of the 9 pitchers who were lost for the season, 6 had avulsion injuries. The other 3 consisted of an LD strain, TM strain, and LD plus TM strain.⁹ In this study, it seems that avulsion injuries had a more significant impact on patient recovery. On average, it took 35.6 days after injury for players to begin throwing. In contrast, it took an average of 65.5 days after an avulsion injury for players to begin throwing. Ellman and colleagues¹⁰ included the only surgically repaired injury, and it was for an avulsion of the LD tendon. In the surgical case, it took slightly longer for the pitcher to return to preinjury form. It took him 12 to 16 weeks to begin light throwing and his full return to pitching took about 20 to 30 weeks. Since muscle strains and tendon avulsions are significantly different injuries in regards to the type of soft tissue damage and healing potential, they may require different treatment strategies. An avulsion injury may require more aggressive intervention, whereas a strain may only require conservative rehabilitation. Ultimately, there does not seem to be a significant benefit of one treatment option compared to the other. The majority of conservatively managed pitchers were able to return to previous form in a reasonable time frame. While each rehabilitation protocol was slightly different, multiple studies advocated for rehab programs that centered around the following goals: slowly progressing pitchers to light throwing once their pain resolved, followed by long throwing, then throwing off of the mound, and finally returning to competitive pitching. It is important to discuss with patients that rehabilitation generally takes 12 to 16 weeks before they are able to fully return to pitching against competition and that rest should immediately follow any recurrence of pain or stiffness. Once those symptoms resolve, patients may continue the rehabilitation protocol.

As with any form of treatment, there are risks involved. This holds true for both conservative and nonconservative therapy for LD and TM injuries. One risk of nonoperative treatment of an LD avulsion is the development of strength deficits in the muscle.¹⁷ While this deficit may go unnoticed in a recreational athlete, it may be more pronounced in a professional athlete, especially since the LD of a professional baseball pitcher is more active on electromyography during the acceleration phase of the pitching cycle compared to a recreational athlete.¹⁸ Another risk of conservative treatment of an LD avulsion is jeopardizing the potential for future surgery. As a result, some advocate for early surgical intervention of an acute LD avulsion.^19,20 Others, however, recommend conservative management with subsequent surgical intervention if conservative measures fail. One caveat is that surgical intervention to restore the original anatomy may become difficult after a certain period of time due to the buildup of scar tissue. Surgical intervention also has associated risks, such as nerve injury, infection, vascular damage, persistent pain, and the buildup of large amounts of scar tissue. It is important to discuss these risks with patients when deciding on a treatment option.

LD and TM avulsion and tears typically present after an acute event in throwing athletes. There are a number of case reports published that demonstrate successful outcomes with both nonoperative management²¹ and operative repair of LD injuries in non-throwing athletes such as competitive water skiers,^22,23 steer wrestlers,²⁴ professional wrestlers,²⁵ and recreational rock climbers.²⁶ The 5 studies included in this review were the first ones to present LD and TM injuries in MLB pitchers. They discussed the outcomes of mainly conservative and surgical management of LD and TM avulsion and tears. Unfortunately, there remains a limited number of cases on the treatment of these injuries in highly competitive throwing athletes. Further research is required to elucidate the advantages and disadvantages of operative vs nonoperative treatment. The goal of this review is to provide clinicians with a concise summary of the current literature so that they may offer some evidence to their patients when discussing appropriate treatment plans.

Upper extremity injuries are very common in pitchers in amateur and professional baseball. The vast majority involving labral or rotator cuff pathology.^1-3 While uncommon, injuries to the latissimus dorsi (LD) (Figure) and teres major (TM) have been reported in Major League Baseball (MLB) pitchers.⁴ Jobe and colleagues⁵ demonstrated the role of the LD during the various phases of pitching. The LD is most active during the acceleration phase and remains active during the deceleration phase and follow-through.⁶ Anatomically, the TM lies posterior to the LD separated by bursal tissue. The tendon fibers converge and unite along their lower borders, leading to a synergistic mechanism of action.

Due to the rarity of LD and TM injuries, literature on the pathology and appropriate treatments for these injuries is limited. The goal of this review is to present the current literature on professional baseball players who have undergone either nonsurgical treatment or surgery for LD and TM strains and/or avulsion injuries. This review will ultimately assist clinicians when deciding on the optimal treatment method for professional baseball players.

Methods

We performed an extensive Medline database search with the following search algorithm: ([latissimus OR latissimus dorsi OR teres major] AND baseball). The search returned 20 citations. Inclusion criteria consisted of clinical studies that focused on professional baseball pitchers with TM and/or LD injuries that underwent either conservative nonsurgical treatment or surgical repair. There was no exclusion based on the type of injury present, such as avulsion vs strain. Any study with amateur athletes or athletes from other sports such as handball or rugby were excluded. Due to the limited amount of data available, the majority of included studies were case reports and case series.

Based on these parameters, 5 articles met criteria for inclusion. Of the 5 included studies, 3 were case reports and 2 were case series. From the eligible articles, the following information was obtained: publication year, sample size, mean age, mean follow-up duration, type of treatment (conservative vs surgical), ability to return to original level of play, time required to return to original form, and complications (Tables 1, 2).

Results

Nonoperative Management

Four of the 5 included studies implemented only conservative therapy for their patients.^4,7-9 The average duration these patients were followed for during treatment and rehabilitation was 26.3 months. Malcolm and colleagues⁷ followed patients for 8 months, the shortest length among the 4 conservative studies in this review. Leland and colleagues8 followed patients for 17 months, and Nagda and colleagues⁹ had the longest length of observation of 36 months (range 12 to 82 months).Schickendantz and colleagues⁴ followed patients for >12 months, but the exact duration was not specified. In order to calculate the average duration of observation, each patient was assigned a duration of 12 months.

Of the 30 patients included in this review, 29 were treated conservatively. All of the included studies consisted of male patients. The mean age was 26.8 years (range 22 to 28.1 years). Of the 29 injuries treated conservatively, there were 2 LD tendon avulsions, 4 TM tendon avulsions, 1 LD and TM tendon avulsion, 7 LD intramuscular strains, 9 TM intramuscular strains, and 6 LD and TM intramuscular strains.

Treatment Protocol

The various treatment and rehabilitation programs used for the conservative patient population all followed a similar pathway. After initial injury, a rest period focused on stretching was implemented. Patients were started on steroid or anti-inflammatory medications, cryotherapy, or other therapeutic modalities. Once pain-free and full range of motion was achieved, patients began the strength and throwing components of the rehabilitation program. Reoccurrence of symptoms would halt the throwing component of the rehabilitation program until symptoms improved. Patients were progressed through a return-to-throw program and once they could throw off the mound and achieve their preinjury velocity, strength, and range of motion, they were cleared to return to competitive pitching.

In the senior author’s (MSS) practice, all throwers are managed with the same nonoperative protocol.⁴ Initial treatment consists of short periods of rest and symptom control via the application of cryotherapy, among other modalities. Restoration of preinjury range of motion is achieved with active-assisted stretching exercises. As range of motion begins approaching pre-injury levels, strength training is initiated with isometric strengthening of the LD and TM progressing to resistance exercises. Exercising the abdominal core, strengthening the lower body, and cardiovascular conditioning are focal points of the rehabilitation period. Once patients regain preinjury shoulder strength and range of motion without pain, they begin a throwing program that consists of 4 weeks of long toss followed by 2 weeks of throwing from the pitching mound. After completion of the throwing program, the patient is allowed to return to competitive pitching. For patients who did not suffer season-ending injury, the average time required to return to play was 99.8 days (range 72.3 to 182.6 days).

 

Complications and Reinjury

The patients in Leland and colleagues⁸ and Malcolm and colleagues⁷ did not suffer any complications or reinjuries. In Schickendantz and colleagues⁴, all but 3 of the 10 patients were able to return to full speed pitching by 3 months. The other 3 required 4, 6, and 10 months. The patient that required 10 months tore both his LD and TM and the patient that required 6 months tore his TM and was never able to regain his pre-injury throwing velocity. None of the TM tears had a recurrence, while 1 LD tear had a recurrence of injury 6 months after returning to competitive pitching. This patient was successfully treated with 6 weeks of conservative rest and rehabilitation.

In Nagda and colleagues⁹, 2 athletes suffered injury recurrence. One athlete with a LD strain suffered 2 subsequent LD strains, 4 months and 1 year after initial injury. The other athlete with a LD avulsion suffered a subsequent TM avulsion 13 months after initial injury. One pitcher who had an LD and TM strain suffered a superior labrum anterior and posterior (SLAP) tear and was never able to return to his prior level of play.

Surgical Treatment

Only 1 of the 5 included studies utilized surgical repair for their patient.¹⁰ The single patient suffered an avulsion injury of the distal LD tendon and its insertion on the humerus. The LD tendon was retracted approximately 5 cm from the distal humeral insertion. The TM was not involved. Eight days post-injury, the patient underwent surgical repair.¹¹ Postoperatively, the patient started passive range of motion after 2 weeks and active range of motion after 6 weeks. He started throwing at 12 weeks and returned to play at 30 weeks after he had returned to his preinjury form in regards to muscle strength, pitch control, and velocity. The patient was able to resume pitching at a high level in MLB.

Discussion

Overhand throwing athletes, especially professional baseball players, have to constantly deal with a variety of shoulder injuries.^12,13 Currently, there is minimal literature on isolated TM and LD injuries. As a result, there is still debate about the optimal treatment method for these injuries, especially in athletes who compete at the highest level. In order to treat isolated injuries of these muscles, it is important to understand their anatomic relationship, as these 2 muscles are intimately associated. The LD originates from the thoracolumbar spine and inserts on the proximal humerus between the pectoralis<hl name="2"/> major and TM tendons. The TM originates from the scapula and, similar to the LD, inserts on the proximal humerus. In an anatomic study, the TM tendon inserted into the LD tendon before its humeral insertion in the majority of cadavers.^14,15

The LD is responsible for extension, adduction, and internal rotation of the humerus. The TM, while not as extensively studied, is believed to also contribute to extension, adduction, and internal rotation of the humerus.¹⁶ As Jobe and colleagues⁵ demonstrated, the LD is vital during the acceleration phase of pitching. While they were unable to make any conclusions about the role of the TM during the pitching cycle, it is reasonable to hypothesize that these 2 muscles work together. While it is thought that these 2 muscles work as a unit, it is significant to note that a professional pitcher can sustain an isolated injury to the TM without injury to the LD, and vice versa. This questions whether these 2 muscles work more independently than once thought. One hypothesis is that the physical size of the LD provides protection from injuries that the smaller TM cannot overcome. This is a potential area of further research.

The most common findings in patients with TM injuries include swelling, bruising, tenderness of the proximal arm, and limitations of shoulder range of motion in abduction, flexion, and external rotation. There is also weakness when resistance is applied against internal rotation and extension. Similar to the TM, common findings in patients with LD injuries include pain in the posterior shoulder, bruising, and weakness when resistance is applied against internal rotation of the shoulder. Pitchers are often able to pinpoint the occurrence of their acute pain during a specific time in the game. They commonly experience a pulling sensation and sometimes even feel a “pop” in their shoulder followed by an acute onset of pain and stiffness in the posterior aspect of the axilla. These injuries seem to be associated with the pitcher throwing a “breaking ball,” a pitch that requires greater shoulder rotation since it changes trajectory while traveling towards home plate. Despite the clear role of the LD and hypothesized role of the TM in the pitching sequence, there has been limited research on the optimal treatment of isolated injuries of these muscles in MLB pitchers. The majority of studies in this review opted for conservative treatment for both LD and TM injuries. The only study that presented a surgical option was for a LD avulsion injury.

 

Athletes undergoing either conservative or surgical treatment required a significant period of recovery and rehabilitation before they were able to compete at the professional level. In Leland and colleagues⁸, it took about 10 to 12 weeks of rehabilitation for both pitchers to return to pitching against competition. In Schickendantz and colleagues⁴, barring any complications or injury recurrence, it took patients 12 weeks to return to their preinjury level. In Malcolm and colleagues⁷, magnetic resonance imaging after 8 weeks showed marked recovery, and shortly after the pitcher was able to return to the pitching rotation. In Nagda and colleagues⁹, the time lost to injury ranged from 7 weeks to an entire season. Of the 9 pitchers who were lost for the season, 6 had avulsion injuries. The other 3 consisted of an LD strain, TM strain, and LD plus TM strain.⁹ In this study, it seems that avulsion injuries had a more significant impact on patient recovery. On average, it took 35.6 days after injury for players to begin throwing. In contrast, it took an average of 65.5 days after an avulsion injury for players to begin throwing. Ellman and colleagues¹⁰ included the only surgically repaired injury, and it was for an avulsion of the LD tendon. In the surgical case, it took slightly longer for the pitcher to return to preinjury form. It took him 12 to 16 weeks to begin light throwing and his full return to pitching took about 20 to 30 weeks. Since muscle strains and tendon avulsions are significantly different injuries in regards to the type of soft tissue damage and healing potential, they may require different treatment strategies. An avulsion injury may require more aggressive intervention, whereas a strain may only require conservative rehabilitation. Ultimately, there does not seem to be a significant benefit of one treatment option compared to the other. The majority of conservatively managed pitchers were able to return to previous form in a reasonable time frame. While each rehabilitation protocol was slightly different, multiple studies advocated for rehab programs that centered around the following goals: slowly progressing pitchers to light throwing once their pain resolved, followed by long throwing, then throwing off of the mound, and finally returning to competitive pitching. It is important to discuss with patients that rehabilitation generally takes 12 to 16 weeks before they are able to fully return to pitching against competition and that rest should immediately follow any recurrence of pain or stiffness. Once those symptoms resolve, patients may continue the rehabilitation protocol.

As with any form of treatment, there are risks involved. This holds true for both conservative and nonconservative therapy for LD and TM injuries. One risk of nonoperative treatment of an LD avulsion is the development of strength deficits in the muscle.¹⁷ While this deficit may go unnoticed in a recreational athlete, it may be more pronounced in a professional athlete, especially since the LD of a professional baseball pitcher is more active on electromyography during the acceleration phase of the pitching cycle compared to a recreational athlete.¹⁸ Another risk of conservative treatment of an LD avulsion is jeopardizing the potential for future surgery. As a result, some advocate for early surgical intervention of an acute LD avulsion.^19,20 Others, however, recommend conservative management with subsequent surgical intervention if conservative measures fail. One caveat is that surgical intervention to restore the original anatomy may become difficult after a certain period of time due to the buildup of scar tissue. Surgical intervention also has associated risks, such as nerve injury, infection, vascular damage, persistent pain, and the buildup of large amounts of scar tissue. It is important to discuss these risks with patients when deciding on a treatment option.

LD and TM avulsion and tears typically present after an acute event in throwing athletes. There are a number of case reports published that demonstrate successful outcomes with both nonoperative management²¹ and operative repair of LD injuries in non-throwing athletes such as competitive water skiers,^22,23 steer wrestlers,²⁴ professional wrestlers,²⁵ and recreational rock climbers.²⁶ The 5 studies included in this review were the first ones to present LD and TM injuries in MLB pitchers. They discussed the outcomes of mainly conservative and surgical management of LD and TM avulsion and tears. Unfortunately, there remains a limited number of cases on the treatment of these injuries in highly competitive throwing athletes. Further research is required to elucidate the advantages and disadvantages of operative vs nonoperative treatment. The goal of this review is to provide clinicians with a concise summary of the current literature so that they may offer some evidence to their patients when discussing appropriate treatment plans.