TORONTO – Hospitalized patients with acute kidney injury had more than double the inpatient rate of venous thromboembolism as had patients without acute kidney injury in a prospective, observational study of more than 6,000 hospitalized U.S. soldiers.

Mitchel L. Zoler/Frontline Medical News

• Patients with AKI are in a hypercoagulable state.
• AKI alters the pharmacodynamics or pharmacokinetics of VTE prophylactic treatments.
• AKI is a marker of an illness that causes VTE.
• VTE leads to an increased rate of AKI rather than the other way around.

Dr. McMahon’s analysis also revealed that two other clinical conditions that are generally believed to raise VTE risk – obesity and impaired overall renal function identified with stagnant measures – did not correspond with a significantly elevated VTE rate in this study.

The data came from 6,552 adults hospitalized for at least 2 days at Walter Reed between September 2009 and March 2011. The study excluded patients with VTE at the time of admission and also those who had been treated with an anticoagulant at the time of admission. The patients averaged 55 years of age and were hospitalized for a median of 4 days. About 22% of patients received VTE prophylaxis with unfractionated heparin, about 41% received prophylaxis with low-molecular-weight heparin, and about 39% received no VTE prophylaxis (percentages total 102% because of rounding).

About 16% of the patients had been diagnosed with AKI at the time of admission, and an additional 8% developed AKI while hospitalized, defined as an increase in serum creatinine during hospitalization of at least 50% above baseline levels or an increase of more than 0.3 mg/dL above the level at time of admission. During hospitalization, 160 patients (2%) developed a new onset VTE.

In an analysis that adjusted for baseline differences in type of surgery, body mass index, sex, age, and prior hospitalizations during the prior 90 days, the results showed that patients with preexisting or new onset AKI had a 2.2-fold higher rate of VTE, compared with patients without AKI, and this difference was statistically significant, Dr. McMahon reported.

The analysis also showed a significant 62% relatively higher rate of VTE among soldiers hospitalized for a deployment-related event, as well as a significant 63% relatively lower VTE rate among patients not receiving medical prophylaxis, compared with patients receiving an anticoagulant. Dr. McMahon suggested that this lower rate of VTEs among patients not on prophylaxis reflected success in identifying which patients had an increased risk for VTE and hence received prophylaxis.

[email protected]

On Twitter @mitchelzoler

TORONTO – Hospitalized patients with acute kidney injury had more than double the inpatient rate of venous thromboembolism as had patients without acute kidney injury in a prospective, observational study of more than 6,000 hospitalized U.S. soldiers.

Mitchel L. Zoler/Frontline Medical News

• Patients with AKI are in a hypercoagulable state.
• AKI alters the pharmacodynamics or pharmacokinetics of VTE prophylactic treatments.
• AKI is a marker of an illness that causes VTE.
• VTE leads to an increased rate of AKI rather than the other way around.

Dr. McMahon’s analysis also revealed that two other clinical conditions that are generally believed to raise VTE risk – obesity and impaired overall renal function identified with stagnant measures – did not correspond with a significantly elevated VTE rate in this study.

The data came from 6,552 adults hospitalized for at least 2 days at Walter Reed between September 2009 and March 2011. The study excluded patients with VTE at the time of admission and also those who had been treated with an anticoagulant at the time of admission. The patients averaged 55 years of age and were hospitalized for a median of 4 days. About 22% of patients received VTE prophylaxis with unfractionated heparin, about 41% received prophylaxis with low-molecular-weight heparin, and about 39% received no VTE prophylaxis (percentages total 102% because of rounding).

About 16% of the patients had been diagnosed with AKI at the time of admission, and an additional 8% developed AKI while hospitalized, defined as an increase in serum creatinine during hospitalization of at least 50% above baseline levels or an increase of more than 0.3 mg/dL above the level at time of admission. During hospitalization, 160 patients (2%) developed a new onset VTE.

In an analysis that adjusted for baseline differences in type of surgery, body mass index, sex, age, and prior hospitalizations during the prior 90 days, the results showed that patients with preexisting or new onset AKI had a 2.2-fold higher rate of VTE, compared with patients without AKI, and this difference was statistically significant, Dr. McMahon reported.

The analysis also showed a significant 62% relatively higher rate of VTE among soldiers hospitalized for a deployment-related event, as well as a significant 63% relatively lower VTE rate among patients not receiving medical prophylaxis, compared with patients receiving an anticoagulant. Dr. McMahon suggested that this lower rate of VTEs among patients not on prophylaxis reflected success in identifying which patients had an increased risk for VTE and hence received prophylaxis.

[email protected]

On Twitter @mitchelzoler

TORONTO – Hospitalized patients with acute kidney injury had more than double the inpatient rate of venous thromboembolism as had patients without acute kidney injury in a prospective, observational study of more than 6,000 hospitalized U.S. soldiers.

Mitchel L. Zoler/Frontline Medical News

• Patients with AKI are in a hypercoagulable state.
• AKI alters the pharmacodynamics or pharmacokinetics of VTE prophylactic treatments.
• AKI is a marker of an illness that causes VTE.
• VTE leads to an increased rate of AKI rather than the other way around.

Dr. McMahon’s analysis also revealed that two other clinical conditions that are generally believed to raise VTE risk – obesity and impaired overall renal function identified with stagnant measures – did not correspond with a significantly elevated VTE rate in this study.

The data came from 6,552 adults hospitalized for at least 2 days at Walter Reed between September 2009 and March 2011. The study excluded patients with VTE at the time of admission and also those who had been treated with an anticoagulant at the time of admission. The patients averaged 55 years of age and were hospitalized for a median of 4 days. About 22% of patients received VTE prophylaxis with unfractionated heparin, about 41% received prophylaxis with low-molecular-weight heparin, and about 39% received no VTE prophylaxis (percentages total 102% because of rounding).

About 16% of the patients had been diagnosed with AKI at the time of admission, and an additional 8% developed AKI while hospitalized, defined as an increase in serum creatinine during hospitalization of at least 50% above baseline levels or an increase of more than 0.3 mg/dL above the level at time of admission. During hospitalization, 160 patients (2%) developed a new onset VTE.

In an analysis that adjusted for baseline differences in type of surgery, body mass index, sex, age, and prior hospitalizations during the prior 90 days, the results showed that patients with preexisting or new onset AKI had a 2.2-fold higher rate of VTE, compared with patients without AKI, and this difference was statistically significant, Dr. McMahon reported.

The analysis also showed a significant 62% relatively higher rate of VTE among soldiers hospitalized for a deployment-related event, as well as a significant 63% relatively lower VTE rate among patients not receiving medical prophylaxis, compared with patients receiving an anticoagulant. Dr. McMahon suggested that this lower rate of VTEs among patients not on prophylaxis reflected success in identifying which patients had an increased risk for VTE and hence received prophylaxis.

[email protected]

On Twitter @mitchelzoler

Most mature surgeons and surgical educators have been asked by hopeful young medical students: “What can I do to improve my chances of becoming a surgeon?” We all want to give our aspiring students encouraging yet truthful answers. The following are typical questions we get from students, and we have tried to provide responses that are both helpful and realistic given the individual circumstances. Do young hopefuls query you about what it takes to become a surgeon? If so, we invite you to let us know what kinds of questions you get and how you respond. We all want “the best and the brightest” to join our profession, and we can help make that happen by offering sound advice to those who come to us asking “How can I become a surgeon?”

Dear Dr. Hughes,

I am a first-year medical student and want to become a surgeon! Everyone tells me I have to have at least two publications to even be considered for an interview. Is this true? What is the best area of research for me to pursue to assure a match in a surgery residency?

Unpublished in the Midwest


Dear Unpublished,

Like almost everything in life, the answer to your question is “It depends.” Surgery is a field that covers such a wide range of opportunities and training options that there is no “perfect” path to residency. More than anything at the M1 level, you need to keep your options open for any discipline. During the next 3 years, you’ll find out much about yourself and about the breadth of medicine. You need to understand who you are as a person before deciding on a specialty and especially before embarking on a research project. Research is a crucial part of surgery, but research just to have a publication for your resume is not a good enough reason to take this on during medical school.

The pursuit of knowledge through research is best undertaken because you have a passion for a particular subject. Most program directors will see right through “insincere” research – that is, research done to puff up a resume but lacking underlying value or relevance to your personal interests.

Most mature surgeons and surgical educators have been asked by hopeful young medical students: “What can I do to improve my chances of becoming a surgeon?” We all want to give our aspiring students encouraging yet truthful answers. The following are typical questions we get from students, and we have tried to provide responses that are both helpful and realistic given the individual circumstances. Do young hopefuls query you about what it takes to become a surgeon? If so, we invite you to let us know what kinds of questions you get and how you respond. We all want “the best and the brightest” to join our profession, and we can help make that happen by offering sound advice to those who come to us asking “How can I become a surgeon?”

Dear Dr. Hughes,

I am a first-year medical student and want to become a surgeon! Everyone tells me I have to have at least two publications to even be considered for an interview. Is this true? What is the best area of research for me to pursue to assure a match in a surgery residency?

Unpublished in the Midwest


Dear Unpublished,

Like almost everything in life, the answer to your question is “It depends.” Surgery is a field that covers such a wide range of opportunities and training options that there is no “perfect” path to residency. More than anything at the M1 level, you need to keep your options open for any discipline. During the next 3 years, you’ll find out much about yourself and about the breadth of medicine. You need to understand who you are as a person before deciding on a specialty and especially before embarking on a research project. Research is a crucial part of surgery, but research just to have a publication for your resume is not a good enough reason to take this on during medical school.

The pursuit of knowledge through research is best undertaken because you have a passion for a particular subject. Most program directors will see right through “insincere” research – that is, research done to puff up a resume but lacking underlying value or relevance to your personal interests.

Most mature surgeons and surgical educators have been asked by hopeful young medical students: “What can I do to improve my chances of becoming a surgeon?” We all want to give our aspiring students encouraging yet truthful answers. The following are typical questions we get from students, and we have tried to provide responses that are both helpful and realistic given the individual circumstances. Do young hopefuls query you about what it takes to become a surgeon? If so, we invite you to let us know what kinds of questions you get and how you respond. We all want “the best and the brightest” to join our profession, and we can help make that happen by offering sound advice to those who come to us asking “How can I become a surgeon?”

Dear Dr. Hughes,

I am a first-year medical student and want to become a surgeon! Everyone tells me I have to have at least two publications to even be considered for an interview. Is this true? What is the best area of research for me to pursue to assure a match in a surgery residency?

Unpublished in the Midwest


Dear Unpublished,

Like almost everything in life, the answer to your question is “It depends.” Surgery is a field that covers such a wide range of opportunities and training options that there is no “perfect” path to residency. More than anything at the M1 level, you need to keep your options open for any discipline. During the next 3 years, you’ll find out much about yourself and about the breadth of medicine. You need to understand who you are as a person before deciding on a specialty and especially before embarking on a research project. Research is a crucial part of surgery, but research just to have a publication for your resume is not a good enough reason to take this on during medical school.

The pursuit of knowledge through research is best undertaken because you have a passion for a particular subject. Most program directors will see right through “insincere” research – that is, research done to puff up a resume but lacking underlying value or relevance to your personal interests.

The concomitant presence of both axial spondyloarthritis (axSpA) and fibromyalgia affects response to tumor necrosis factor (TNF) blockers through increased symptom severity on patient-reported outcomes but not on more objective measurements, according to findings from a prospective, longitudinal study.

SOURCE: Moltó A et al. Ann Rheum Dis. 2017 Nov 28. doi: 10.1136/annrheumdis-2017-212378.

The concomitant presence of both axial spondyloarthritis (axSpA) and fibromyalgia affects response to tumor necrosis factor (TNF) blockers through increased symptom severity on patient-reported outcomes but not on more objective measurements, according to findings from a prospective, longitudinal study.

SOURCE: Moltó A et al. Ann Rheum Dis. 2017 Nov 28. doi: 10.1136/annrheumdis-2017-212378.

The concomitant presence of both axial spondyloarthritis (axSpA) and fibromyalgia affects response to tumor necrosis factor (TNF) blockers through increased symptom severity on patient-reported outcomes but not on more objective measurements, according to findings from a prospective, longitudinal study.

SOURCE: Moltó A et al. Ann Rheum Dis. 2017 Nov 28. doi: 10.1136/annrheumdis-2017-212378.

SAN ANTONIO – Clinical trials have shown a clear benefit for preventing breast cancer recurrence with aromatase inhibitor (AI) therapy following 5 years of tamoxifen. Yet the optimal duration for additional AI therapy following 5 years of endocrine therapy with tamoxifen, an AI, or sequential therapies is not known, according to Michael Gnant, MD, from the Medical University of Vienna.

In the ABCSG-16 trial, Dr. Gnant and his colleagues reported that 5 years of additional therapy with anastrozole (Arimidex) was no more effective than 2 additional years following the standard 5 years of initial endocrine therapy in postmenopausal women with hormone receptor–positive (HR+) breast cancer.

In this video interview at the San Antonio Breast Cancer Symposium, Dr. Gnant notes that, although some patients may still benefit from 5 years of additional therapy, the trial results suggest that most patients can be spared from such adverse events as risk for fractures associated with three additional and evidently unnecessary years of therapy.

The ABCSG-16 study was supported by AstraZeneca. Dr. Gnant disclosed research funding, honoraria, and travel funding from the company and others.

[email protected]

SAN ANTONIO – Clinical trials have shown a clear benefit for preventing breast cancer recurrence with aromatase inhibitor (AI) therapy following 5 years of tamoxifen. Yet the optimal duration for additional AI therapy following 5 years of endocrine therapy with tamoxifen, an AI, or sequential therapies is not known, according to Michael Gnant, MD, from the Medical University of Vienna.

In the ABCSG-16 trial, Dr. Gnant and his colleagues reported that 5 years of additional therapy with anastrozole (Arimidex) was no more effective than 2 additional years following the standard 5 years of initial endocrine therapy in postmenopausal women with hormone receptor–positive (HR+) breast cancer.

In this video interview at the San Antonio Breast Cancer Symposium, Dr. Gnant notes that, although some patients may still benefit from 5 years of additional therapy, the trial results suggest that most patients can be spared from such adverse events as risk for fractures associated with three additional and evidently unnecessary years of therapy.

The ABCSG-16 study was supported by AstraZeneca. Dr. Gnant disclosed research funding, honoraria, and travel funding from the company and others.

[email protected]

SAN ANTONIO – Clinical trials have shown a clear benefit for preventing breast cancer recurrence with aromatase inhibitor (AI) therapy following 5 years of tamoxifen. Yet the optimal duration for additional AI therapy following 5 years of endocrine therapy with tamoxifen, an AI, or sequential therapies is not known, according to Michael Gnant, MD, from the Medical University of Vienna.

In the ABCSG-16 trial, Dr. Gnant and his colleagues reported that 5 years of additional therapy with anastrozole (Arimidex) was no more effective than 2 additional years following the standard 5 years of initial endocrine therapy in postmenopausal women with hormone receptor–positive (HR+) breast cancer.

In this video interview at the San Antonio Breast Cancer Symposium, Dr. Gnant notes that, although some patients may still benefit from 5 years of additional therapy, the trial results suggest that most patients can be spared from such adverse events as risk for fractures associated with three additional and evidently unnecessary years of therapy.

The ABCSG-16 study was supported by AstraZeneca. Dr. Gnant disclosed research funding, honoraria, and travel funding from the company and others.

[email protected]

SAN DIEGO – Systematic testing of acute respiratory illness patients can increase the likelihood of finding relevant pathogens, according to a study presented at an annual scientific meeting on infectious diseases.

Currently, hospitals conduct either nonroutine assessments or rely heavily on clinical laboratory testing among severe acute respiratory illness patients, which can lead to missing clinically key viruses.

Cynthia Goldsmith/CDC photo #10073

[email protected]

SOURCE: Steffens A et al. Abstract 885.

SAN DIEGO – Systematic testing of acute respiratory illness patients can increase the likelihood of finding relevant pathogens, according to a study presented at an annual scientific meeting on infectious diseases.

Currently, hospitals conduct either nonroutine assessments or rely heavily on clinical laboratory testing among severe acute respiratory illness patients, which can lead to missing clinically key viruses.

Cynthia Goldsmith/CDC photo #10073

[email protected]

SOURCE: Steffens A et al. Abstract 885.

SAN DIEGO – Systematic testing of acute respiratory illness patients can increase the likelihood of finding relevant pathogens, according to a study presented at an annual scientific meeting on infectious diseases.

Currently, hospitals conduct either nonroutine assessments or rely heavily on clinical laboratory testing among severe acute respiratory illness patients, which can lead to missing clinically key viruses.

Cynthia Goldsmith/CDC photo #10073

[email protected]

SOURCE: Steffens A et al. Abstract 885.

WASHINGTON, DC—Treatment of obstructive sleep apnea (OSA) with positive airway pressure (PAP) is associated with better one-year seizure outcomes in patients with epilepsy, according to a study presented at the 71st Annual Meeting of the American Epilepsy Society.

Prior research has suggested that sleep disturbances are more common in people with epilepsy than in age-matched controls and that more than 40% of people with epilepsy have OSA. PAP therapy has been associated with seizure reduction in small case series.

To compare long-term seizure control between patients with PAP-treated OSA, patients with untreated OSA, and patients without OSA, Thapanee Somboon, MD, a research fellow at the Sleep Disorders Center at Cleveland Clinic, and colleagues conducted a retrospective study of adults with epilepsy who underwent polysomnography at Cleveland Clinic between 1997 and 2015. Researchers compared patients’ seizure outcomes at one, three, and five years after polysomnography.

—Jake Remaly

WASHINGTON, DC—Treatment of obstructive sleep apnea (OSA) with positive airway pressure (PAP) is associated with better one-year seizure outcomes in patients with epilepsy, according to a study presented at the 71st Annual Meeting of the American Epilepsy Society.

Prior research has suggested that sleep disturbances are more common in people with epilepsy than in age-matched controls and that more than 40% of people with epilepsy have OSA. PAP therapy has been associated with seizure reduction in small case series.

To compare long-term seizure control between patients with PAP-treated OSA, patients with untreated OSA, and patients without OSA, Thapanee Somboon, MD, a research fellow at the Sleep Disorders Center at Cleveland Clinic, and colleagues conducted a retrospective study of adults with epilepsy who underwent polysomnography at Cleveland Clinic between 1997 and 2015. Researchers compared patients’ seizure outcomes at one, three, and five years after polysomnography.

—Jake Remaly

WASHINGTON, DC—Treatment of obstructive sleep apnea (OSA) with positive airway pressure (PAP) is associated with better one-year seizure outcomes in patients with epilepsy, according to a study presented at the 71st Annual Meeting of the American Epilepsy Society.

Prior research has suggested that sleep disturbances are more common in people with epilepsy than in age-matched controls and that more than 40% of people with epilepsy have OSA. PAP therapy has been associated with seizure reduction in small case series.

To compare long-term seizure control between patients with PAP-treated OSA, patients with untreated OSA, and patients without OSA, Thapanee Somboon, MD, a research fellow at the Sleep Disorders Center at Cleveland Clinic, and colleagues conducted a retrospective study of adults with epilepsy who underwent polysomnography at Cleveland Clinic between 1997 and 2015. Researchers compared patients’ seizure outcomes at one, three, and five years after polysomnography.

—Jake Remaly

While value has become an imperative in both training and health care delivery, few tools exist to teach hospitalists and other providers the basic concepts of value.

“Hospitalists are on the front lines of health care value delivery, and it is critical that we understand and embrace the concepts of value; however, we also need to be able to deliver upon these ideals,” said Christopher Moriates, MD, assistant dean for health care value at the University of Texas at Austin.

While value has become an imperative in both training and health care delivery, few tools exist to teach hospitalists and other providers the basic concepts of value.

“Hospitalists are on the front lines of health care value delivery, and it is critical that we understand and embrace the concepts of value; however, we also need to be able to deliver upon these ideals,” said Christopher Moriates, MD, assistant dean for health care value at the University of Texas at Austin.

While value has become an imperative in both training and health care delivery, few tools exist to teach hospitalists and other providers the basic concepts of value.

“Hospitalists are on the front lines of health care value delivery, and it is critical that we understand and embrace the concepts of value; however, we also need to be able to deliver upon these ideals,” said Christopher Moriates, MD, assistant dean for health care value at the University of Texas at Austin.

A clinical trial has been initiated to study robotic-assisted laparoscopic sacrocolpopexy surgery. Robotic Assisted Sacral Colpopexy: A Prospective Study Assessing Outcomes With Learning Curves is an open-label study that is being conducted on a new pelvic floor program for women with pelvic organ prolapse.

A prospective cohort of 100 patients will be recruited and the study will assess surgical time (total and specific essential portions), simulator training, and observed surgeon skills. Secondary endpoints include subjective outcomes for issues of sexual function and incontinence and adverse events such as genitourinary injury, blood loss, wound infection, and mesh erosion.

[email protected]

SOURCE: ClinicalTrials.gov: NCT01535833.

A clinical trial has been initiated to study robotic-assisted laparoscopic sacrocolpopexy surgery. Robotic Assisted Sacral Colpopexy: A Prospective Study Assessing Outcomes With Learning Curves is an open-label study that is being conducted on a new pelvic floor program for women with pelvic organ prolapse.

A prospective cohort of 100 patients will be recruited and the study will assess surgical time (total and specific essential portions), simulator training, and observed surgeon skills. Secondary endpoints include subjective outcomes for issues of sexual function and incontinence and adverse events such as genitourinary injury, blood loss, wound infection, and mesh erosion.

[email protected]

SOURCE: ClinicalTrials.gov: NCT01535833.

A clinical trial has been initiated to study robotic-assisted laparoscopic sacrocolpopexy surgery. Robotic Assisted Sacral Colpopexy: A Prospective Study Assessing Outcomes With Learning Curves is an open-label study that is being conducted on a new pelvic floor program for women with pelvic organ prolapse.

A prospective cohort of 100 patients will be recruited and the study will assess surgical time (total and specific essential portions), simulator training, and observed surgeon skills. Secondary endpoints include subjective outcomes for issues of sexual function and incontinence and adverse events such as genitourinary injury, blood loss, wound infection, and mesh erosion.

[email protected]

SOURCE: ClinicalTrials.gov: NCT01535833.

Take-Home Points

• There is a 41% rate of AVN or PTOA after operatively managed talus fracture.
• Surgical timing does not affect development of AVN or PTOA.
• Open fractures are associated with development of AVN and PTOA.
• Quality of reduction is likely more important than timing of reduction.
• Urgent surgical treatment is necessary for threatened soft tissue or neurovascular compromise.

Talus fractures are rare injuries that present a significant treatment dilemma.^1-12 These fractures represent <1% of all fractures⁴ and are second only to calcaneus fractures in fractures of the hindfoot. Talus fractures with associated dislocations are even rarer and may provide treating surgeons with a significant surgical quandary.^6,13-16

Talus fractures historically have been characterized by their anatomical location: head, neck, or body. Two systems are commonly used to classify talus fractures: Hawkins and AO/OTA (Arbeitsgemeinschaft für Osteosynthesefragen/Orthopaedic Trauma Association). The first, developed by Hawkins⁷ and modified by Canale and Kelly² and Vallier and colleagues,¹ identifies 4 basic fracture types with associated dislocations. The other system, published in 1996¹⁷ and republished in 2007,¹⁸ uses the combined methods of AO and OTA to systematically describe talus fractures. Although these classification systems accurately describe talus fractures with associated dislocation, both have difficulty predicting clinical outcomes.^1,19,20

Talus fractures commonly result in avascular necrosis (AVN) of the talus and posttraumatic osteoarthritis (PTOA) of the tibiotalar and subtalar joints.^{3,8,9,12,14-16} Hawkins⁷ initially described subchondral lucency as indicating revascularization of the talus after injury. AVN and PTOA rates traditionally have been thought to be related to a blood supply disruption, given the prognostic value of the Hawkins sign.^1,7,12,21 New methods, including a dual-incision approach and expedited transfer to foot and ankle surgeons or orthopedic traumatologists, have improved reduction quality^21-24 but not patient outcomes.^{3,5,8,9,12,14}

Recently, time from injury to surgical intervention has been a topic of much discussion, and there have been studies on the specific effects of timing with respect to outcome.^1,15,16 Vallier and colleagues,¹ who wanted to identify injury characteristics predictive of osteonecrosis, found that delaying reduction and surgical fixation did not increase the risk of AVN. Another study found that urgent reduction of fracture-dislocation with delayed open reduction and internal fixation (ORIF) using a dual approach may improve clinical outcomes.²¹

In this vein, we conducted a study to evaluate the effect of time to surgical reduction of talus fractures and talus fracture-dislocations on the development of AVN and PTOA. We hypothesized that time to surgical reduction of talus fracture-dislocation as classified with the AO/OTA system would have no effect of the development of AVN/PTOA.

Methods

After this study received Institutional Review Board approval, we retrospectively reviewed the records on talus fractures surgically managed at a level I trauma center during the 10-year period 2003 to 2013. Of the 119 potential cases identified using Current Procedural Terminology code 28445 (ORIF of talus), 13 were excluded (12 for inaccurate coding or missing documentation, 1 for being a pediatric case), leaving 106 for analysis. Using the Hawkins and AO/OTA systems, 3 independent reviewers classified the injuries on plain radiographs.

Injury dates and times were obtained from the medical records. Operating room start times were also obtained. Surgical timing was defined as time from injury to operating room start. For cases without an injury time, time of presentation to emergency department was used.

Open fracture-dislocations were managed with intravenous antibiotics, urgent surgical irrigation, débridement, and immediate fixation or temporizing external fixation after reduction. All fractures were definitively managed with standard ORIF with an anteromedial, anterolateral, or dual approach and mini-fragment implants. After fixation, weight-bearing typically was restricted for 6 to 12 weeks.

Follow-up radiographs were evaluated. Presence or absence of Hawkins sign⁷ was noted on radiographs at 6 or 8 weeks, and all follow-up radiographs were evaluated for AVN as defined by increased radiographic density within the talar dome or collapse of the articular surface. All radiographs were evaluated for PTOA as defined by loss of joint space within the tibiotalar, subtalar, or talonavicular joint on follow-up radiographs.

Clinical outcomes were analyzed for development of AVN, PTOA, or secondary corrective surgery or arthrodesis. Continuous variables were evaluated with the t test, and the χ² test was used to compare distributions of categorical variables. The Wilcoxon rank sum test was used to compare non-normally distributed variables. Significance was set at P < .05.

 

 

Results

Classification Analysis (Table 1)

Subject Analysis (Table 2)

The mechanisms of injury were motor vehicle accident (70/106; 66%), fall from height (25; 24%), misstep (4), sports related (2), object falling on ankle (2), and not reported (3). 

Of the 106 patients, 45 (42%) had isolated talus injuries, 35 had concomitant ipsilateral lower extremity injuries, 25 had concomitant contralateral lower extremity injuries, and 1 had a concomitant upper extremity injury. 

Smoking status was everyday (14 patients), past (10), never (34), and unreported (48). Five patients reported a history of alcohol abuse, and 4 patients reported illicit drug use. Two had a history of atrial fibrillation, 9 had hypertension, 3 had hyperlipidemia, 3 had renal disease, 3 had heart disease, 4 had diabetes, 3 had lung disease, and 1 had a history of lung cancer.

Overall Analysis of AVN/PTOA (Table 3)

Analysis of AVN/PTOA in 81-B3 Fracture-Dislocations (Table 4)

 

 

Analysis of AVN/PTOA in All Other Talus Fractures (Table 5)

Discussion

Our results showed that time from talus fracture-dislocation to surgical reduction had no effect on development of AVN/PTOA. The findings in this largest series to date agree with earlier findings^1,8,15,16,24 and add to the volume of literature suggesting that time to surgical reduction of talus fractures and talus fracture-dislocations does not markedly affect outcome.

Talus fractures continue to present a significant treatment dilemma. Despite recent improvements in surgical techniques and overall management of these injuries, rates of AVN and PTOA have not significantly decreased.^1,16,23 At most treating facilities, talus fracture-dislocations are considered surgical emergencies/urgencies, and every effort is made to reduce and surgically address these injuries as soon as possible.^1,13

In this study, rates of AVN/PTOA were 41% (all talus fractures) and 50% (displaced talar neck fractures), and the difference was not significant (Table 3). These rates are higher but consistent with previously reported rates (range, 14%-49%).^{1,2,7-9,12,14,24} There was no difference in surgical timing for development of AVN/PTOA. We analyzed the cases of all patients who had talus fractures and developed AVN/PTOA (43/106). Within this group, there were no significant differences in surgical timing, age, sex, polytrauma, or BMI between patients who developed AVN/PTOA and those who did not. Compared with patients who did not develop AVN/PTOA, those who developed AVN/PTOA were significantly more likely to have open injuries. This finding, consistent with those in other reports^9,12,13 (Table 3), indicates outcome is more likely related to injury severity and not necessarily injury class.

We retrospectively analyzed talus fractures and talus fracture-dislocations to determine if urgent surgical management affects outcomes. Current practice at our institution is to routinely reduce and surgically address these fractures urgently, often during the middle of the night, when orthopedic resources are reduced. Our study found a significant difference in surgical timing for patients with talus fracture-dislocations and patients with talus fractures without dislocations (Table 2). Given our findings, urgent surgical reduction and fixation are not indicated to preserve the talus blood supply and prevent AVN/PTOA, though we still recommend urgent surgical management in the setting of an open wound, skin necrosis, or soft-tissue/neurovascular compromise. 

This study had several limitations, primarily related to its retrospective nature. Surgical timing was defined as time from injury, as noted in the medical record, to operating room start. In some instances, time of injury was not noted in the medical record, and time of presentation to emergency room was used instead. Thus, surgical timing for these patients may have been longer than identified. In addition, given the rare injury pattern and the retrospective design, this study was susceptible to type II error and may have been underpowered to detect whether time to surgical reduction predicted complications. Also, the study did not address functional outcome as measured by validated outcome scores. Outcome measures were obtained in many but not all cases, making functional outcome measurement difficult. Similarly, the quality of the anatomical reductions was not assessed, potentially affecting complication rates. Postoperative reduction assessment, possibly performed with computed tomography, is an avenue of further study.

Strengths of this study include its large sample size (this was one of the largest studies of talus fractures), long follow-up (mean, 150 weeks), and novel use of AO/OTA classification.

We postulate that development of AVN/PTOA is not necessarily related to the urgency or timing of surgical reduction and fixation and is more likely related to injury severity. This idea is supported by the finding that development of AVN/PTOA was significantly correlated to open injuries in all talus fractures, including talus fracture-dislocations and isolated talus fractures.

Conclusion 

Talus fracture-dislocations are devastating injuries with high rates of complications. In this study, open talus fractures, and fractures with associated tibiotalar or subtalar dislocations, had higher complication rates. Given the evidence presented, we recommend basing surgical timing on injury severity, not necessarily for AVN/PTOA prevention. Specifically, in the absence of an open wound, skin necrosis, or soft-tissue/neurovascular compromise, talus fracture-dislocations can be surgically reduced and stabilized when optimal resources are available.

Take-Home Points

• There is a 41% rate of AVN or PTOA after operatively managed talus fracture.
• Surgical timing does not affect development of AVN or PTOA.
• Open fractures are associated with development of AVN and PTOA.
• Quality of reduction is likely more important than timing of reduction.
• Urgent surgical treatment is necessary for threatened soft tissue or neurovascular compromise.

Talus fractures are rare injuries that present a significant treatment dilemma.^1-12 These fractures represent <1% of all fractures⁴ and are second only to calcaneus fractures in fractures of the hindfoot. Talus fractures with associated dislocations are even rarer and may provide treating surgeons with a significant surgical quandary.^6,13-16

Talus fractures historically have been characterized by their anatomical location: head, neck, or body. Two systems are commonly used to classify talus fractures: Hawkins and AO/OTA (Arbeitsgemeinschaft für Osteosynthesefragen/Orthopaedic Trauma Association). The first, developed by Hawkins⁷ and modified by Canale and Kelly² and Vallier and colleagues,¹ identifies 4 basic fracture types with associated dislocations. The other system, published in 1996¹⁷ and republished in 2007,¹⁸ uses the combined methods of AO and OTA to systematically describe talus fractures. Although these classification systems accurately describe talus fractures with associated dislocation, both have difficulty predicting clinical outcomes.^1,19,20

Talus fractures commonly result in avascular necrosis (AVN) of the talus and posttraumatic osteoarthritis (PTOA) of the tibiotalar and subtalar joints.^{3,8,9,12,14-16} Hawkins⁷ initially described subchondral lucency as indicating revascularization of the talus after injury. AVN and PTOA rates traditionally have been thought to be related to a blood supply disruption, given the prognostic value of the Hawkins sign.^1,7,12,21 New methods, including a dual-incision approach and expedited transfer to foot and ankle surgeons or orthopedic traumatologists, have improved reduction quality^21-24 but not patient outcomes.^{3,5,8,9,12,14}

Recently, time from injury to surgical intervention has been a topic of much discussion, and there have been studies on the specific effects of timing with respect to outcome.^1,15,16 Vallier and colleagues,¹ who wanted to identify injury characteristics predictive of osteonecrosis, found that delaying reduction and surgical fixation did not increase the risk of AVN. Another study found that urgent reduction of fracture-dislocation with delayed open reduction and internal fixation (ORIF) using a dual approach may improve clinical outcomes.²¹

In this vein, we conducted a study to evaluate the effect of time to surgical reduction of talus fractures and talus fracture-dislocations on the development of AVN and PTOA. We hypothesized that time to surgical reduction of talus fracture-dislocation as classified with the AO/OTA system would have no effect of the development of AVN/PTOA.

Methods

After this study received Institutional Review Board approval, we retrospectively reviewed the records on talus fractures surgically managed at a level I trauma center during the 10-year period 2003 to 2013. Of the 119 potential cases identified using Current Procedural Terminology code 28445 (ORIF of talus), 13 were excluded (12 for inaccurate coding or missing documentation, 1 for being a pediatric case), leaving 106 for analysis. Using the Hawkins and AO/OTA systems, 3 independent reviewers classified the injuries on plain radiographs.

Injury dates and times were obtained from the medical records. Operating room start times were also obtained. Surgical timing was defined as time from injury to operating room start. For cases without an injury time, time of presentation to emergency department was used.

Open fracture-dislocations were managed with intravenous antibiotics, urgent surgical irrigation, débridement, and immediate fixation or temporizing external fixation after reduction. All fractures were definitively managed with standard ORIF with an anteromedial, anterolateral, or dual approach and mini-fragment implants. After fixation, weight-bearing typically was restricted for 6 to 12 weeks.

Follow-up radiographs were evaluated. Presence or absence of Hawkins sign⁷ was noted on radiographs at 6 or 8 weeks, and all follow-up radiographs were evaluated for AVN as defined by increased radiographic density within the talar dome or collapse of the articular surface. All radiographs were evaluated for PTOA as defined by loss of joint space within the tibiotalar, subtalar, or talonavicular joint on follow-up radiographs.

Clinical outcomes were analyzed for development of AVN, PTOA, or secondary corrective surgery or arthrodesis. Continuous variables were evaluated with the t test, and the χ² test was used to compare distributions of categorical variables. The Wilcoxon rank sum test was used to compare non-normally distributed variables. Significance was set at P < .05.

 

 

Results

Classification Analysis (Table 1)

Subject Analysis (Table 2)

The mechanisms of injury were motor vehicle accident (70/106; 66%), fall from height (25; 24%), misstep (4), sports related (2), object falling on ankle (2), and not reported (3). 

Of the 106 patients, 45 (42%) had isolated talus injuries, 35 had concomitant ipsilateral lower extremity injuries, 25 had concomitant contralateral lower extremity injuries, and 1 had a concomitant upper extremity injury. 

Smoking status was everyday (14 patients), past (10), never (34), and unreported (48). Five patients reported a history of alcohol abuse, and 4 patients reported illicit drug use. Two had a history of atrial fibrillation, 9 had hypertension, 3 had hyperlipidemia, 3 had renal disease, 3 had heart disease, 4 had diabetes, 3 had lung disease, and 1 had a history of lung cancer.

Overall Analysis of AVN/PTOA (Table 3)

Analysis of AVN/PTOA in 81-B3 Fracture-Dislocations (Table 4)

 

 

Analysis of AVN/PTOA in All Other Talus Fractures (Table 5)

Discussion

Our results showed that time from talus fracture-dislocation to surgical reduction had no effect on development of AVN/PTOA. The findings in this largest series to date agree with earlier findings^1,8,15,16,24 and add to the volume of literature suggesting that time to surgical reduction of talus fractures and talus fracture-dislocations does not markedly affect outcome.

Talus fractures continue to present a significant treatment dilemma. Despite recent improvements in surgical techniques and overall management of these injuries, rates of AVN and PTOA have not significantly decreased.^1,16,23 At most treating facilities, talus fracture-dislocations are considered surgical emergencies/urgencies, and every effort is made to reduce and surgically address these injuries as soon as possible.^1,13

In this study, rates of AVN/PTOA were 41% (all talus fractures) and 50% (displaced talar neck fractures), and the difference was not significant (Table 3). These rates are higher but consistent with previously reported rates (range, 14%-49%).^{1,2,7-9,12,14,24} There was no difference in surgical timing for development of AVN/PTOA. We analyzed the cases of all patients who had talus fractures and developed AVN/PTOA (43/106). Within this group, there were no significant differences in surgical timing, age, sex, polytrauma, or BMI between patients who developed AVN/PTOA and those who did not. Compared with patients who did not develop AVN/PTOA, those who developed AVN/PTOA were significantly more likely to have open injuries. This finding, consistent with those in other reports^9,12,13 (Table 3), indicates outcome is more likely related to injury severity and not necessarily injury class.

We retrospectively analyzed talus fractures and talus fracture-dislocations to determine if urgent surgical management affects outcomes. Current practice at our institution is to routinely reduce and surgically address these fractures urgently, often during the middle of the night, when orthopedic resources are reduced. Our study found a significant difference in surgical timing for patients with talus fracture-dislocations and patients with talus fractures without dislocations (Table 2). Given our findings, urgent surgical reduction and fixation are not indicated to preserve the talus blood supply and prevent AVN/PTOA, though we still recommend urgent surgical management in the setting of an open wound, skin necrosis, or soft-tissue/neurovascular compromise. 

This study had several limitations, primarily related to its retrospective nature. Surgical timing was defined as time from injury, as noted in the medical record, to operating room start. In some instances, time of injury was not noted in the medical record, and time of presentation to emergency room was used instead. Thus, surgical timing for these patients may have been longer than identified. In addition, given the rare injury pattern and the retrospective design, this study was susceptible to type II error and may have been underpowered to detect whether time to surgical reduction predicted complications. Also, the study did not address functional outcome as measured by validated outcome scores. Outcome measures were obtained in many but not all cases, making functional outcome measurement difficult. Similarly, the quality of the anatomical reductions was not assessed, potentially affecting complication rates. Postoperative reduction assessment, possibly performed with computed tomography, is an avenue of further study.

Strengths of this study include its large sample size (this was one of the largest studies of talus fractures), long follow-up (mean, 150 weeks), and novel use of AO/OTA classification.

We postulate that development of AVN/PTOA is not necessarily related to the urgency or timing of surgical reduction and fixation and is more likely related to injury severity. This idea is supported by the finding that development of AVN/PTOA was significantly correlated to open injuries in all talus fractures, including talus fracture-dislocations and isolated talus fractures.

Conclusion 

Talus fracture-dislocations are devastating injuries with high rates of complications. In this study, open talus fractures, and fractures with associated tibiotalar or subtalar dislocations, had higher complication rates. Given the evidence presented, we recommend basing surgical timing on injury severity, not necessarily for AVN/PTOA prevention. Specifically, in the absence of an open wound, skin necrosis, or soft-tissue/neurovascular compromise, talus fracture-dislocations can be surgically reduced and stabilized when optimal resources are available.

Take-Home Points

• There is a 41% rate of AVN or PTOA after operatively managed talus fracture.
• Surgical timing does not affect development of AVN or PTOA.
• Open fractures are associated with development of AVN and PTOA.
• Quality of reduction is likely more important than timing of reduction.
• Urgent surgical treatment is necessary for threatened soft tissue or neurovascular compromise.

Talus fractures are rare injuries that present a significant treatment dilemma.^1-12 These fractures represent <1% of all fractures⁴ and are second only to calcaneus fractures in fractures of the hindfoot. Talus fractures with associated dislocations are even rarer and may provide treating surgeons with a significant surgical quandary.^6,13-16

Talus fractures historically have been characterized by their anatomical location: head, neck, or body. Two systems are commonly used to classify talus fractures: Hawkins and AO/OTA (Arbeitsgemeinschaft für Osteosynthesefragen/Orthopaedic Trauma Association). The first, developed by Hawkins⁷ and modified by Canale and Kelly² and Vallier and colleagues,¹ identifies 4 basic fracture types with associated dislocations. The other system, published in 1996¹⁷ and republished in 2007,¹⁸ uses the combined methods of AO and OTA to systematically describe talus fractures. Although these classification systems accurately describe talus fractures with associated dislocation, both have difficulty predicting clinical outcomes.^1,19,20

Talus fractures commonly result in avascular necrosis (AVN) of the talus and posttraumatic osteoarthritis (PTOA) of the tibiotalar and subtalar joints.^{3,8,9,12,14-16} Hawkins⁷ initially described subchondral lucency as indicating revascularization of the talus after injury. AVN and PTOA rates traditionally have been thought to be related to a blood supply disruption, given the prognostic value of the Hawkins sign.^1,7,12,21 New methods, including a dual-incision approach and expedited transfer to foot and ankle surgeons or orthopedic traumatologists, have improved reduction quality^21-24 but not patient outcomes.^{3,5,8,9,12,14}

Recently, time from injury to surgical intervention has been a topic of much discussion, and there have been studies on the specific effects of timing with respect to outcome.^1,15,16 Vallier and colleagues,¹ who wanted to identify injury characteristics predictive of osteonecrosis, found that delaying reduction and surgical fixation did not increase the risk of AVN. Another study found that urgent reduction of fracture-dislocation with delayed open reduction and internal fixation (ORIF) using a dual approach may improve clinical outcomes.²¹

In this vein, we conducted a study to evaluate the effect of time to surgical reduction of talus fractures and talus fracture-dislocations on the development of AVN and PTOA. We hypothesized that time to surgical reduction of talus fracture-dislocation as classified with the AO/OTA system would have no effect of the development of AVN/PTOA.

Methods

After this study received Institutional Review Board approval, we retrospectively reviewed the records on talus fractures surgically managed at a level I trauma center during the 10-year period 2003 to 2013. Of the 119 potential cases identified using Current Procedural Terminology code 28445 (ORIF of talus), 13 were excluded (12 for inaccurate coding or missing documentation, 1 for being a pediatric case), leaving 106 for analysis. Using the Hawkins and AO/OTA systems, 3 independent reviewers classified the injuries on plain radiographs.

Injury dates and times were obtained from the medical records. Operating room start times were also obtained. Surgical timing was defined as time from injury to operating room start. For cases without an injury time, time of presentation to emergency department was used.

Open fracture-dislocations were managed with intravenous antibiotics, urgent surgical irrigation, débridement, and immediate fixation or temporizing external fixation after reduction. All fractures were definitively managed with standard ORIF with an anteromedial, anterolateral, or dual approach and mini-fragment implants. After fixation, weight-bearing typically was restricted for 6 to 12 weeks.

Follow-up radiographs were evaluated. Presence or absence of Hawkins sign⁷ was noted on radiographs at 6 or 8 weeks, and all follow-up radiographs were evaluated for AVN as defined by increased radiographic density within the talar dome or collapse of the articular surface. All radiographs were evaluated for PTOA as defined by loss of joint space within the tibiotalar, subtalar, or talonavicular joint on follow-up radiographs.

Clinical outcomes were analyzed for development of AVN, PTOA, or secondary corrective surgery or arthrodesis. Continuous variables were evaluated with the t test, and the χ² test was used to compare distributions of categorical variables. The Wilcoxon rank sum test was used to compare non-normally distributed variables. Significance was set at P < .05.

 

 

Results

Classification Analysis (Table 1)

Subject Analysis (Table 2)

The mechanisms of injury were motor vehicle accident (70/106; 66%), fall from height (25; 24%), misstep (4), sports related (2), object falling on ankle (2), and not reported (3). 

Of the 106 patients, 45 (42%) had isolated talus injuries, 35 had concomitant ipsilateral lower extremity injuries, 25 had concomitant contralateral lower extremity injuries, and 1 had a concomitant upper extremity injury. 

Smoking status was everyday (14 patients), past (10), never (34), and unreported (48). Five patients reported a history of alcohol abuse, and 4 patients reported illicit drug use. Two had a history of atrial fibrillation, 9 had hypertension, 3 had hyperlipidemia, 3 had renal disease, 3 had heart disease, 4 had diabetes, 3 had lung disease, and 1 had a history of lung cancer.

Overall Analysis of AVN/PTOA (Table 3)

Analysis of AVN/PTOA in 81-B3 Fracture-Dislocations (Table 4)

 

 

Analysis of AVN/PTOA in All Other Talus Fractures (Table 5)

Discussion

Our results showed that time from talus fracture-dislocation to surgical reduction had no effect on development of AVN/PTOA. The findings in this largest series to date agree with earlier findings^1,8,15,16,24 and add to the volume of literature suggesting that time to surgical reduction of talus fractures and talus fracture-dislocations does not markedly affect outcome.

Talus fractures continue to present a significant treatment dilemma. Despite recent improvements in surgical techniques and overall management of these injuries, rates of AVN and PTOA have not significantly decreased.^1,16,23 At most treating facilities, talus fracture-dislocations are considered surgical emergencies/urgencies, and every effort is made to reduce and surgically address these injuries as soon as possible.^1,13

In this study, rates of AVN/PTOA were 41% (all talus fractures) and 50% (displaced talar neck fractures), and the difference was not significant (Table 3). These rates are higher but consistent with previously reported rates (range, 14%-49%).^{1,2,7-9,12,14,24} There was no difference in surgical timing for development of AVN/PTOA. We analyzed the cases of all patients who had talus fractures and developed AVN/PTOA (43/106). Within this group, there were no significant differences in surgical timing, age, sex, polytrauma, or BMI between patients who developed AVN/PTOA and those who did not. Compared with patients who did not develop AVN/PTOA, those who developed AVN/PTOA were significantly more likely to have open injuries. This finding, consistent with those in other reports^9,12,13 (Table 3), indicates outcome is more likely related to injury severity and not necessarily injury class.

We retrospectively analyzed talus fractures and talus fracture-dislocations to determine if urgent surgical management affects outcomes. Current practice at our institution is to routinely reduce and surgically address these fractures urgently, often during the middle of the night, when orthopedic resources are reduced. Our study found a significant difference in surgical timing for patients with talus fracture-dislocations and patients with talus fractures without dislocations (Table 2). Given our findings, urgent surgical reduction and fixation are not indicated to preserve the talus blood supply and prevent AVN/PTOA, though we still recommend urgent surgical management in the setting of an open wound, skin necrosis, or soft-tissue/neurovascular compromise. 

This study had several limitations, primarily related to its retrospective nature. Surgical timing was defined as time from injury, as noted in the medical record, to operating room start. In some instances, time of injury was not noted in the medical record, and time of presentation to emergency room was used instead. Thus, surgical timing for these patients may have been longer than identified. In addition, given the rare injury pattern and the retrospective design, this study was susceptible to type II error and may have been underpowered to detect whether time to surgical reduction predicted complications. Also, the study did not address functional outcome as measured by validated outcome scores. Outcome measures were obtained in many but not all cases, making functional outcome measurement difficult. Similarly, the quality of the anatomical reductions was not assessed, potentially affecting complication rates. Postoperative reduction assessment, possibly performed with computed tomography, is an avenue of further study.

Strengths of this study include its large sample size (this was one of the largest studies of talus fractures), long follow-up (mean, 150 weeks), and novel use of AO/OTA classification.

We postulate that development of AVN/PTOA is not necessarily related to the urgency or timing of surgical reduction and fixation and is more likely related to injury severity. This idea is supported by the finding that development of AVN/PTOA was significantly correlated to open injuries in all talus fractures, including talus fracture-dislocations and isolated talus fractures.

Conclusion 

Talus fracture-dislocations are devastating injuries with high rates of complications. In this study, open talus fractures, and fractures with associated tibiotalar or subtalar dislocations, had higher complication rates. Given the evidence presented, we recommend basing surgical timing on injury severity, not necessarily for AVN/PTOA prevention. Specifically, in the absence of an open wound, skin necrosis, or soft-tissue/neurovascular compromise, talus fracture-dislocations can be surgically reduced and stabilized when optimal resources are available.

Take-Home Points

• Cellular healing response differs between bony and soft tissue biceps tenodesis.
• Bony tenodesis incites an inflammatory healing response.
• Bony tenodesis healing occurs at the tendon-bone interface.
• Intrasseous bony fixation leads to tendon degeneration within the bone.
• Tendon-to-tendon tenodesis may result in regenerative tendon healing.

The long head of the biceps tendon (LHBT) is a well-established pain generator of the anterior shoulder^1,2 and may be surgically addressed in refractory cases.³ According to a recent study of 44,932 cases, biceps tenodesis rates increased 80% over just 3 years (2008-2011).⁴ Nevertheless, optimal tenodesis location and technique remain controversial. Proximal and distal tenodesis, including numerous soft-tissue and bony techniques, have been described.^5-7 Several studies have focused on the biomechanical strength of various fixation modalities.^8-14 These data highlight the ongoing evolution of our understanding of biceps-labrum complex (BLC) disease.

Over the years, tenodesis location has proved to be an important factor in outcomes.^3,15-20 Several recent studies have elucidated the role of the extra-articular LHBT and the limited capabilities of diagnostic arthroscopy.^15-17,20,21 Taylor and colleagues¹⁷ defined the bicipital tunnel as the extra-articular segment of LHBT and its fibro-osseous enclosure. The tunnel extends from the articular margin through the subpectoral region and can be divided into 3 zones: Zone 1 goes from the articular margin to the inferior margin of the subscapularis, zone 2 goes from the inferior margin of the subscapularis to the proximal margin of the pectoralis major tendon, and zone 3 is the subpectoral region. Zone 2 is often referred to as “no man’s land” for its relative invisibility from arthroscopy above and open exposure below.^17,21 Notably, a recent study reported a 47% prevalence of hidden tunnel lesions in patients with chronic BLC disease symptoms.¹⁸ Other studies have shown that standard proximal tenodesis methods often fail to address LHBT pathology in this area, leading to residual symptoms.^9,22 It is evident that tenodesis location and technique play important roles in patient outcomes. Sanders and colleagues¹⁶ found that the revision rate was significantly higher among patients who underwent biceps tenodesis without release of the bicipital tunnel sheath than among patients who underwent tenodesis with the release. Dr. O’Brien developed an alternative option: soft-tissue tenodesis with transfer of the LHBT to the conjoint tendon within the subdeltoid space.^23,24 This technique addresses intra-articular and extra-articular tunnel disease while mitigating the complications associated with bony tenodesis. Early and midterm studies have shown this to be an effective intervention for chronically symptomatic BLC disease.^25,26

Despite the abundance of literature on tenodesis techniques, no one has histologically evaluated the location-dependent healing and inflammatory responses. We conducted a study to determine the impact of tenodesis location on healing and inflammation in a rat model. We hypothesized that, compared with tendon-to-bone techniques, soft-tissue tenodesis would minimize inflammatory response and optimize healing.

Methods 

The study was approved by the Institutional Animal Care and Use Committee at the Hospital for Special Surgery. 

Animals

Biceps tenodesis was performed at 1 of 3 locations in 36 thirteen-week-old Sprague-Dawley rats (Charles River Laboratories). All rats were prepared for surgery by an experienced veterinary technician. Sedation was induced with isoflurane gas through a nose cone. 

Surgical Procedure

Animals were randomly assigned to 3 different tenodesis groups: tendon-to-bone in the bicipital groove (metaphyseal, M); tendon-to-bone in the subpectoral region (diaphyseal, D); and soft tissue-to-soft tissue transfer to the conjoint tendon (T). A standard deltopectoral approach was used to expose the biceps tendon. The tendon was tagged with a 5-0 polypropylene suture and tenotomized at the level of the bicipital groove (zone 1). All wounds were irrigated and closed with 4-0 nylon suture.

For animals undergoing tendon-to-bone metaphyseal tenodesis, a 0.045-mm Kirschner wire was used to drill bicortically into the intertubercular sulcus. Wire positioning distal to the physeal plate was confirmed with fluoroscopy. A locking stitch of 5-0 polypropylene suture was run along the free edge of the tendon. The tendon was then passed through the bone tunnel in an anterior-to-posterior direction, and the limbs of the suture were tied around the lateral cortex. 

The process was repeated for animals undergoing diaphyseal tenodesis; only the tenodesis location was different. The inferior border of the pectoralis major was identified, and a bicortical tunnel was made in the center of the diaphyseal bone. The tendon was then prepared and tenodesed to bone using the method already described.

In soft-tissue tenodesis, the conjoint tendon was identified and carefully dissected from surrounding tissues. The LHBT was then tenodesed to the attached conjoint tendon with interrupted simple stitches of 5-0 polypropylene suture.

The animals were allowed to bear weight on the operative limb immediately after surgery and without immobilization.

Specimen Harvest and Preparation

Four animals from each group were sacrificed at 6, 12, and 24 weeks. Harvested specimens were fixed in 10% neutral-buffered formalin solution. Bony specimens consisted of the upper half of the humerus and the tenodesed biceps tendon, and soft-tissue specimens consisted of the tenodesed LHBT-conjoint tendon complex. Bony specimens were decalcified in 10% ethylenediaminetetraacetic acid. All specimens were paraffin-embedded and sectioned at 7 microns.

Analysis of Cellularity

Sections were stained with hematoxylin-eosin. Overall cellularity at the tenodesis interface was quantified by averaging the nuclei count within 3 separate standardized ×20 magnification high power fields. Only nucleated cells were included in the cell count. Immunohistochemical staining with tenomodulin (Santa Cruz Laboratories, sc-49324) was performed to characterize the cell population at the interface. Deparaffinized sections underwent antigen retrieval with pronase for 30 minutes at 37°C and were incubated overnight with the anti-tenomodulin goat monoclonal antibody diluted to 1:200 in 1% phosphate-buffered saline. The prepared slides were then counterstained with methyl green. Specimens treated with tenomodulin were evaluated for presence or absence of a positive reaction at the tenodesis interface. 

Analysis of Inflammation

Inflammation at the interface was evaluated with the CD68 macrophage marker (ABcam, ab31630). Deparaffinized sections underwent antigen retrieval with pronase for 30 minutes at 37°C and were incubated overnight with anti-CD68 mouse monoclonal antibodies diluted to 1:200 in 1% phosphate-buffered saline. The prepared slides were then counterstained with neutral red. Inflammation was quantified by averaging the number of reactive cells within 3 separate standardized ×20 magnification high power fields.

Statistical Analysis

Descriptive statistics were calculated for cell and macrophage counts for each group at every time point. Two-way analysis of variance was used to compare the cell and macrophage counts between groups at each time point as well as the count differences within each group between time points. P values were Bonferroni-corrected to account for the multiple comparisons between groups. P < .05 was used to signify statistical significance.

Results

All 36 animals survived to their designated harvest time without complications. Twelve specimens were successfully harvested at 6 weeks and another 12 at 24 weeks. At 12 weeks, tenodesis failure occurred in 1 animal in group D, leaving 11 specimens for analysis.

Cellularity

Within-group analysis revealed a trend of increasing cellularity at 12 weeks followed by a decrease at 24 weeks in all 3 groups (Table 2).

Inflammatory Response 

During specimen processing, 1 group D specimen was severely degraded after pronase treatment, leaving 3 specimens for evaluation. Descriptive statistics for each group are listed in Table 3A.

At 6 weeks, mean CD68 cell count was significantly higher in group M than in group D (P = .011) and group T (P < .001) (Table 3B). Likewise, CD68 count was significantly higher in group D than in group T (P < .001). There were no differences in CD68 counts between the 2 bony tenodesis groups at 12 weeks (P = .486) or 24 weeks (P = .315). Both bony tenodesis groups, however, had persistently higher CD68 counts at 12 weeks when compared with group T (group M, P = .002; group D, P < .001). In these specimens, an inflammatory milieu characterized by a large accumulation of lymphocytes and giant cells was noted at the bone-tendon interface.

Tissue-Specific Staining

At 6 weeks, antigen retrieval resulted in severe degradation of 2 group M specimens, 2 group D specimens, and 1 group T specimen. The most notable tenomodulin reaction occurred in group T at the 6- and 12-week harvests, with the 6-week group having the most robust reaction. There was scant reaction in this group at 24 weeks.

Discussion

In this study, the healing response differed between bony and soft-tissue tenodesis techniques in a rat model. Tendon-to-bone tenodesis, both diaphyseal and metaphyseal, appeared to incite an inflammatory degenerative response, whereas tendon-to-tendon healing occurred in a more quiescent and perhaps even regenerative manner.

The early inflammatory response that occurred in the bony tenodesis groups is not unlike what occurs in fracture healing.²⁷ The reaction was even more robust at 12 weeks, signifying an ongoing inflammatory process. In this context, tendon degeneration may plausibly explain the consistent absence of mature tendon within the tunnels at all 3 time points. Some tendon degeneration may be explained by the vascular damage that occurred during surgery, but this damage was a constant factor in all 3 study groups. Interestingly, group M showed the highest early CD68 counts, consistent with this being the more biologically active region of bone.²⁸

Group T had significantly lower cell and macrophage counts throughout the study period, possibly indicating improved healing—an observation supported by a study in which the impact of macrophage depletion on bone-tendon interface healing was evaluated.²⁹ The authors found that, in suppressing macrophage activity, the morphologic and biomechanical properties at the healing interface were significantly improved.²⁹ These findings are consistent with Dr. O’Brien’s anecdotal experience with patients who previously underwent the biceps transfer; on second-look arthroscopy, there was complete seamless integration of tendon and conjoint tendon (Figure 4). 

Studies have found that the inflammatory process is closely associated with pain, and pain syndromes such as fibromyalgia.^30,31 Persistent inflammation, as seen in our bony tenodesis group, could explain the recalcitrant anterior shoulder pain that often occurs in patients after bony tenodesis of the LHBT.^2,6,19,32 

Studies have also suggested that osteoclasts at the bone-tendon interface—osteoclasts share a cell lineage with macrophages—may contribute to bone loss and tunnel widening.^33,34 Osteoclasts are expected at the bone tunnel, as fracture healing occurs at the bone-tendon interface. These osteoclasts could have contributed to the strong CD68 reaction in our bony tenodesis groups. However, CD68 historically has been described as the classic macrophage marker.³⁵ We specifically selected CD68 for this reason: Macrophages are the primary inflammatory cells involved in early healing and are key to the inflammatory process.³⁶

Results of the tenomodulin analysis suggested 2 different healing processes are occurring in the bony and tendon groups. Tenomodulin is a known tenocyte marker for developing and mature tendon in both rats and humans.^37,38 In our study, only group T had a positive tenomodulin reaction. Notably, the reaction occurred only at 6 and 12 weeks. This finding may indicate that a regenerative healing pattern becomes quiescent by 24 weeks. Indeed, it has been suggested that tenomodulin is a key regulator of tenocyte proliferation and tendon maturation.³⁹

The complete absence of tenomodulin reaction in our bony tenodesis groups in the setting of significant inflammation further supports our theory of tendon degeneration within the tunnel. One potential explanation for this finding may be that as the tendon heals to the surface of the bone, the intra-osseous tendon is no longer load-bearing and is resorbed by the body through an inflammatory response. This finding differs from those in previous studies, which have described viable tendon within the bone tunnel at all time points up to 26 weeks.⁴⁰ More recently, it has been suggested that callus formation at the external cortical tendon-bone interface is critical for healing and mechanical strength.^41,42 In addition, recent studies have found a predominantly fibroblastic healing process at the midtunnel, potentially leading to the formation of loose fibrovascular tissue at the tendon-bone interface.⁴³ These data, in concert with ours, call into question the rationale for performing intra-osseous tenodesis through bone tunnels.

Our study results, if confirmed in humans, will have significant clinical implications. If a similar effect can be confirmed in the human shoulder, one could argue that soft-tissue tenodesis may result in decreased postoperative shoulder pain. In addition, if tendon degeneration does occur within the intramedullary tunnel, surface fixation may be the better, safer alternative. Although older studies reported suboptimal strength with this type of fixation,^8,44 more recent studies have found surface fixation strength equivalent to screw fixation strength.^45,46 Such a shift in the treatment paradigm would obviate the need for violation of the humeral cortex, eliminating potential stress risers associated with screw fixation,⁴⁷ and effectively eliminating the risk of iatrogenic fracture.^48,49 It would be interesting to investigate what occurs histologically at the bone-tendon interface in surface fixation (ie, suture anchors). Would the inflammatory response at the surface be similar to the inflammatory intramedullary healing, or would it be similar to the quieter tendon-tendon healing? Answers to such questions have the potential to streamline the treatment algorithm for patients who require tenodesis.

Study Limitations

Our study had several limitations. First, as this was a basic science study using a rat model, its conclusions can only be extrapolated to humans. Second, given the nonspecific nature of the cellular analysis, we cannot draw any definitive conclusions about the cell population at the bone-tendon interface. For example, although tenomodulin is expressed by tenocytes, it is not an established specific marker for tenocytes and may be expressed by other fibroblastic cells. Still, our results provide insight into the local microenvironment and identify important differences between the tenodesis methods. Similarly, the complete absence of tendon within the bone tunnels suggests that an analysis of osteoclastic activity at the tenodesis interface may have been a valuable addition to the study. This finding, however, was unexpected, and we did not have the foresight to include it in our methods. A third limitation is that our fixation method essentially uses the suspension tenodesis method. This fixation method differs from the common fixation techniques used in the clinical setting. Testing of other fixation constructs would require a larger animal model. Furthermore, in suspension- type constructs, micromotion within the bone tunnel may independently elicit an inflammatory response. Inert suture was used in our fixation in order to reduce the risk of an iatrogenic inflammatory response. Last, it would have been valuable to perform a biomechanical analysis of the strength of each tenodesis construct. This was explored with our institution’s biomechanics team, but specimen size precluded successful analysis.

Conclusion

Our results indicated that, compared with tendon-to-tendon fixation, tendon-to-bone tenodesis produces a significantly greater inflammatory response at the tenodesis interface. An inflammatory milieu in the absence of tendon within the bony tunnel suggests intraosseous tendon degeneration. Tendon-to-tendon tenodesis, on the other hand, seems to limit the inflammatory response. In addition, a robust tenomodulin reaction in the early phases of tendon-to-tendon healing suggests regenerative healing. Our results showed a fundamental difference in the healing response between the 2 tenodesis methods. Further study is needed to evaluate the validity and applicability of our findings to the human patient population. Most important, our results underscore the need for more study to elucidate optimal tenodesis location and encourage orthopedic surgeons to reexamine current clinical practice patterns.

Take-Home Points

• Cellular healing response differs between bony and soft tissue biceps tenodesis.
• Bony tenodesis incites an inflammatory healing response.
• Bony tenodesis healing occurs at the tendon-bone interface.
• Intrasseous bony fixation leads to tendon degeneration within the bone.
• Tendon-to-tendon tenodesis may result in regenerative tendon healing.

The long head of the biceps tendon (LHBT) is a well-established pain generator of the anterior shoulder^1,2 and may be surgically addressed in refractory cases.³ According to a recent study of 44,932 cases, biceps tenodesis rates increased 80% over just 3 years (2008-2011).⁴ Nevertheless, optimal tenodesis location and technique remain controversial. Proximal and distal tenodesis, including numerous soft-tissue and bony techniques, have been described.^5-7 Several studies have focused on the biomechanical strength of various fixation modalities.^8-14 These data highlight the ongoing evolution of our understanding of biceps-labrum complex (BLC) disease.

Over the years, tenodesis location has proved to be an important factor in outcomes.^3,15-20 Several recent studies have elucidated the role of the extra-articular LHBT and the limited capabilities of diagnostic arthroscopy.^15-17,20,21 Taylor and colleagues¹⁷ defined the bicipital tunnel as the extra-articular segment of LHBT and its fibro-osseous enclosure. The tunnel extends from the articular margin through the subpectoral region and can be divided into 3 zones: Zone 1 goes from the articular margin to the inferior margin of the subscapularis, zone 2 goes from the inferior margin of the subscapularis to the proximal margin of the pectoralis major tendon, and zone 3 is the subpectoral region. Zone 2 is often referred to as “no man’s land” for its relative invisibility from arthroscopy above and open exposure below.^17,21 Notably, a recent study reported a 47% prevalence of hidden tunnel lesions in patients with chronic BLC disease symptoms.¹⁸ Other studies have shown that standard proximal tenodesis methods often fail to address LHBT pathology in this area, leading to residual symptoms.^9,22 It is evident that tenodesis location and technique play important roles in patient outcomes. Sanders and colleagues¹⁶ found that the revision rate was significantly higher among patients who underwent biceps tenodesis without release of the bicipital tunnel sheath than among patients who underwent tenodesis with the release. Dr. O’Brien developed an alternative option: soft-tissue tenodesis with transfer of the LHBT to the conjoint tendon within the subdeltoid space.^23,24 This technique addresses intra-articular and extra-articular tunnel disease while mitigating the complications associated with bony tenodesis. Early and midterm studies have shown this to be an effective intervention for chronically symptomatic BLC disease.^25,26

Despite the abundance of literature on tenodesis techniques, no one has histologically evaluated the location-dependent healing and inflammatory responses. We conducted a study to determine the impact of tenodesis location on healing and inflammation in a rat model. We hypothesized that, compared with tendon-to-bone techniques, soft-tissue tenodesis would minimize inflammatory response and optimize healing.

Methods 

The study was approved by the Institutional Animal Care and Use Committee at the Hospital for Special Surgery. 

Animals

Biceps tenodesis was performed at 1 of 3 locations in 36 thirteen-week-old Sprague-Dawley rats (Charles River Laboratories). All rats were prepared for surgery by an experienced veterinary technician. Sedation was induced with isoflurane gas through a nose cone. 

Surgical Procedure

Animals were randomly assigned to 3 different tenodesis groups: tendon-to-bone in the bicipital groove (metaphyseal, M); tendon-to-bone in the subpectoral region (diaphyseal, D); and soft tissue-to-soft tissue transfer to the conjoint tendon (T). A standard deltopectoral approach was used to expose the biceps tendon. The tendon was tagged with a 5-0 polypropylene suture and tenotomized at the level of the bicipital groove (zone 1). All wounds were irrigated and closed with 4-0 nylon suture.

For animals undergoing tendon-to-bone metaphyseal tenodesis, a 0.045-mm Kirschner wire was used to drill bicortically into the intertubercular sulcus. Wire positioning distal to the physeal plate was confirmed with fluoroscopy. A locking stitch of 5-0 polypropylene suture was run along the free edge of the tendon. The tendon was then passed through the bone tunnel in an anterior-to-posterior direction, and the limbs of the suture were tied around the lateral cortex. 

The process was repeated for animals undergoing diaphyseal tenodesis; only the tenodesis location was different. The inferior border of the pectoralis major was identified, and a bicortical tunnel was made in the center of the diaphyseal bone. The tendon was then prepared and tenodesed to bone using the method already described.

In soft-tissue tenodesis, the conjoint tendon was identified and carefully dissected from surrounding tissues. The LHBT was then tenodesed to the attached conjoint tendon with interrupted simple stitches of 5-0 polypropylene suture.

The animals were allowed to bear weight on the operative limb immediately after surgery and without immobilization.

Specimen Harvest and Preparation

Four animals from each group were sacrificed at 6, 12, and 24 weeks. Harvested specimens were fixed in 10% neutral-buffered formalin solution. Bony specimens consisted of the upper half of the humerus and the tenodesed biceps tendon, and soft-tissue specimens consisted of the tenodesed LHBT-conjoint tendon complex. Bony specimens were decalcified in 10% ethylenediaminetetraacetic acid. All specimens were paraffin-embedded and sectioned at 7 microns.

Analysis of Cellularity

Sections were stained with hematoxylin-eosin. Overall cellularity at the tenodesis interface was quantified by averaging the nuclei count within 3 separate standardized ×20 magnification high power fields. Only nucleated cells were included in the cell count. Immunohistochemical staining with tenomodulin (Santa Cruz Laboratories, sc-49324) was performed to characterize the cell population at the interface. Deparaffinized sections underwent antigen retrieval with pronase for 30 minutes at 37°C and were incubated overnight with the anti-tenomodulin goat monoclonal antibody diluted to 1:200 in 1% phosphate-buffered saline. The prepared slides were then counterstained with methyl green. Specimens treated with tenomodulin were evaluated for presence or absence of a positive reaction at the tenodesis interface. 

Analysis of Inflammation

Inflammation at the interface was evaluated with the CD68 macrophage marker (ABcam, ab31630). Deparaffinized sections underwent antigen retrieval with pronase for 30 minutes at 37°C and were incubated overnight with anti-CD68 mouse monoclonal antibodies diluted to 1:200 in 1% phosphate-buffered saline. The prepared slides were then counterstained with neutral red. Inflammation was quantified by averaging the number of reactive cells within 3 separate standardized ×20 magnification high power fields.

Statistical Analysis

Descriptive statistics were calculated for cell and macrophage counts for each group at every time point. Two-way analysis of variance was used to compare the cell and macrophage counts between groups at each time point as well as the count differences within each group between time points. P values were Bonferroni-corrected to account for the multiple comparisons between groups. P < .05 was used to signify statistical significance.

Results

All 36 animals survived to their designated harvest time without complications. Twelve specimens were successfully harvested at 6 weeks and another 12 at 24 weeks. At 12 weeks, tenodesis failure occurred in 1 animal in group D, leaving 11 specimens for analysis.

Cellularity

Within-group analysis revealed a trend of increasing cellularity at 12 weeks followed by a decrease at 24 weeks in all 3 groups (Table 2).

Inflammatory Response 

During specimen processing, 1 group D specimen was severely degraded after pronase treatment, leaving 3 specimens for evaluation. Descriptive statistics for each group are listed in Table 3A.

At 6 weeks, mean CD68 cell count was significantly higher in group M than in group D (P = .011) and group T (P < .001) (Table 3B). Likewise, CD68 count was significantly higher in group D than in group T (P < .001). There were no differences in CD68 counts between the 2 bony tenodesis groups at 12 weeks (P = .486) or 24 weeks (P = .315). Both bony tenodesis groups, however, had persistently higher CD68 counts at 12 weeks when compared with group T (group M, P = .002; group D, P < .001). In these specimens, an inflammatory milieu characterized by a large accumulation of lymphocytes and giant cells was noted at the bone-tendon interface.

Tissue-Specific Staining

At 6 weeks, antigen retrieval resulted in severe degradation of 2 group M specimens, 2 group D specimens, and 1 group T specimen. The most notable tenomodulin reaction occurred in group T at the 6- and 12-week harvests, with the 6-week group having the most robust reaction. There was scant reaction in this group at 24 weeks.

Discussion

In this study, the healing response differed between bony and soft-tissue tenodesis techniques in a rat model. Tendon-to-bone tenodesis, both diaphyseal and metaphyseal, appeared to incite an inflammatory degenerative response, whereas tendon-to-tendon healing occurred in a more quiescent and perhaps even regenerative manner.

The early inflammatory response that occurred in the bony tenodesis groups is not unlike what occurs in fracture healing.²⁷ The reaction was even more robust at 12 weeks, signifying an ongoing inflammatory process. In this context, tendon degeneration may plausibly explain the consistent absence of mature tendon within the tunnels at all 3 time points. Some tendon degeneration may be explained by the vascular damage that occurred during surgery, but this damage was a constant factor in all 3 study groups. Interestingly, group M showed the highest early CD68 counts, consistent with this being the more biologically active region of bone.²⁸

Group T had significantly lower cell and macrophage counts throughout the study period, possibly indicating improved healing—an observation supported by a study in which the impact of macrophage depletion on bone-tendon interface healing was evaluated.²⁹ The authors found that, in suppressing macrophage activity, the morphologic and biomechanical properties at the healing interface were significantly improved.²⁹ These findings are consistent with Dr. O’Brien’s anecdotal experience with patients who previously underwent the biceps transfer; on second-look arthroscopy, there was complete seamless integration of tendon and conjoint tendon (Figure 4). 

Studies have found that the inflammatory process is closely associated with pain, and pain syndromes such as fibromyalgia.^30,31 Persistent inflammation, as seen in our bony tenodesis group, could explain the recalcitrant anterior shoulder pain that often occurs in patients after bony tenodesis of the LHBT.^2,6,19,32 

Studies have also suggested that osteoclasts at the bone-tendon interface—osteoclasts share a cell lineage with macrophages—may contribute to bone loss and tunnel widening.^33,34 Osteoclasts are expected at the bone tunnel, as fracture healing occurs at the bone-tendon interface. These osteoclasts could have contributed to the strong CD68 reaction in our bony tenodesis groups. However, CD68 historically has been described as the classic macrophage marker.³⁵ We specifically selected CD68 for this reason: Macrophages are the primary inflammatory cells involved in early healing and are key to the inflammatory process.³⁶

Results of the tenomodulin analysis suggested 2 different healing processes are occurring in the bony and tendon groups. Tenomodulin is a known tenocyte marker for developing and mature tendon in both rats and humans.^37,38 In our study, only group T had a positive tenomodulin reaction. Notably, the reaction occurred only at 6 and 12 weeks. This finding may indicate that a regenerative healing pattern becomes quiescent by 24 weeks. Indeed, it has been suggested that tenomodulin is a key regulator of tenocyte proliferation and tendon maturation.³⁹

The complete absence of tenomodulin reaction in our bony tenodesis groups in the setting of significant inflammation further supports our theory of tendon degeneration within the tunnel. One potential explanation for this finding may be that as the tendon heals to the surface of the bone, the intra-osseous tendon is no longer load-bearing and is resorbed by the body through an inflammatory response. This finding differs from those in previous studies, which have described viable tendon within the bone tunnel at all time points up to 26 weeks.⁴⁰ More recently, it has been suggested that callus formation at the external cortical tendon-bone interface is critical for healing and mechanical strength.^41,42 In addition, recent studies have found a predominantly fibroblastic healing process at the midtunnel, potentially leading to the formation of loose fibrovascular tissue at the tendon-bone interface.⁴³ These data, in concert with ours, call into question the rationale for performing intra-osseous tenodesis through bone tunnels.

Our study results, if confirmed in humans, will have significant clinical implications. If a similar effect can be confirmed in the human shoulder, one could argue that soft-tissue tenodesis may result in decreased postoperative shoulder pain. In addition, if tendon degeneration does occur within the intramedullary tunnel, surface fixation may be the better, safer alternative. Although older studies reported suboptimal strength with this type of fixation,^8,44 more recent studies have found surface fixation strength equivalent to screw fixation strength.^45,46 Such a shift in the treatment paradigm would obviate the need for violation of the humeral cortex, eliminating potential stress risers associated with screw fixation,⁴⁷ and effectively eliminating the risk of iatrogenic fracture.^48,49 It would be interesting to investigate what occurs histologically at the bone-tendon interface in surface fixation (ie, suture anchors). Would the inflammatory response at the surface be similar to the inflammatory intramedullary healing, or would it be similar to the quieter tendon-tendon healing? Answers to such questions have the potential to streamline the treatment algorithm for patients who require tenodesis.

Study Limitations

Our study had several limitations. First, as this was a basic science study using a rat model, its conclusions can only be extrapolated to humans. Second, given the nonspecific nature of the cellular analysis, we cannot draw any definitive conclusions about the cell population at the bone-tendon interface. For example, although tenomodulin is expressed by tenocytes, it is not an established specific marker for tenocytes and may be expressed by other fibroblastic cells. Still, our results provide insight into the local microenvironment and identify important differences between the tenodesis methods. Similarly, the complete absence of tendon within the bone tunnels suggests that an analysis of osteoclastic activity at the tenodesis interface may have been a valuable addition to the study. This finding, however, was unexpected, and we did not have the foresight to include it in our methods. A third limitation is that our fixation method essentially uses the suspension tenodesis method. This fixation method differs from the common fixation techniques used in the clinical setting. Testing of other fixation constructs would require a larger animal model. Furthermore, in suspension- type constructs, micromotion within the bone tunnel may independently elicit an inflammatory response. Inert suture was used in our fixation in order to reduce the risk of an iatrogenic inflammatory response. Last, it would have been valuable to perform a biomechanical analysis of the strength of each tenodesis construct. This was explored with our institution’s biomechanics team, but specimen size precluded successful analysis.

Conclusion

Our results indicated that, compared with tendon-to-tendon fixation, tendon-to-bone tenodesis produces a significantly greater inflammatory response at the tenodesis interface. An inflammatory milieu in the absence of tendon within the bony tunnel suggests intraosseous tendon degeneration. Tendon-to-tendon tenodesis, on the other hand, seems to limit the inflammatory response. In addition, a robust tenomodulin reaction in the early phases of tendon-to-tendon healing suggests regenerative healing. Our results showed a fundamental difference in the healing response between the 2 tenodesis methods. Further study is needed to evaluate the validity and applicability of our findings to the human patient population. Most important, our results underscore the need for more study to elucidate optimal tenodesis location and encourage orthopedic surgeons to reexamine current clinical practice patterns.

Take-Home Points

• Cellular healing response differs between bony and soft tissue biceps tenodesis.
• Bony tenodesis incites an inflammatory healing response.
• Bony tenodesis healing occurs at the tendon-bone interface.
• Intrasseous bony fixation leads to tendon degeneration within the bone.
• Tendon-to-tendon tenodesis may result in regenerative tendon healing.

The long head of the biceps tendon (LHBT) is a well-established pain generator of the anterior shoulder^1,2 and may be surgically addressed in refractory cases.³ According to a recent study of 44,932 cases, biceps tenodesis rates increased 80% over just 3 years (2008-2011).⁴ Nevertheless, optimal tenodesis location and technique remain controversial. Proximal and distal tenodesis, including numerous soft-tissue and bony techniques, have been described.^5-7 Several studies have focused on the biomechanical strength of various fixation modalities.^8-14 These data highlight the ongoing evolution of our understanding of biceps-labrum complex (BLC) disease.

Over the years, tenodesis location has proved to be an important factor in outcomes.^3,15-20 Several recent studies have elucidated the role of the extra-articular LHBT and the limited capabilities of diagnostic arthroscopy.^15-17,20,21 Taylor and colleagues¹⁷ defined the bicipital tunnel as the extra-articular segment of LHBT and its fibro-osseous enclosure. The tunnel extends from the articular margin through the subpectoral region and can be divided into 3 zones: Zone 1 goes from the articular margin to the inferior margin of the subscapularis, zone 2 goes from the inferior margin of the subscapularis to the proximal margin of the pectoralis major tendon, and zone 3 is the subpectoral region. Zone 2 is often referred to as “no man’s land” for its relative invisibility from arthroscopy above and open exposure below.^17,21 Notably, a recent study reported a 47% prevalence of hidden tunnel lesions in patients with chronic BLC disease symptoms.¹⁸ Other studies have shown that standard proximal tenodesis methods often fail to address LHBT pathology in this area, leading to residual symptoms.^9,22 It is evident that tenodesis location and technique play important roles in patient outcomes. Sanders and colleagues¹⁶ found that the revision rate was significantly higher among patients who underwent biceps tenodesis without release of the bicipital tunnel sheath than among patients who underwent tenodesis with the release. Dr. O’Brien developed an alternative option: soft-tissue tenodesis with transfer of the LHBT to the conjoint tendon within the subdeltoid space.^23,24 This technique addresses intra-articular and extra-articular tunnel disease while mitigating the complications associated with bony tenodesis. Early and midterm studies have shown this to be an effective intervention for chronically symptomatic BLC disease.^25,26

Despite the abundance of literature on tenodesis techniques, no one has histologically evaluated the location-dependent healing and inflammatory responses. We conducted a study to determine the impact of tenodesis location on healing and inflammation in a rat model. We hypothesized that, compared with tendon-to-bone techniques, soft-tissue tenodesis would minimize inflammatory response and optimize healing.

Methods 

The study was approved by the Institutional Animal Care and Use Committee at the Hospital for Special Surgery. 

Animals

Biceps tenodesis was performed at 1 of 3 locations in 36 thirteen-week-old Sprague-Dawley rats (Charles River Laboratories). All rats were prepared for surgery by an experienced veterinary technician. Sedation was induced with isoflurane gas through a nose cone. 

Surgical Procedure

Animals were randomly assigned to 3 different tenodesis groups: tendon-to-bone in the bicipital groove (metaphyseal, M); tendon-to-bone in the subpectoral region (diaphyseal, D); and soft tissue-to-soft tissue transfer to the conjoint tendon (T). A standard deltopectoral approach was used to expose the biceps tendon. The tendon was tagged with a 5-0 polypropylene suture and tenotomized at the level of the bicipital groove (zone 1). All wounds were irrigated and closed with 4-0 nylon suture.

For animals undergoing tendon-to-bone metaphyseal tenodesis, a 0.045-mm Kirschner wire was used to drill bicortically into the intertubercular sulcus. Wire positioning distal to the physeal plate was confirmed with fluoroscopy. A locking stitch of 5-0 polypropylene suture was run along the free edge of the tendon. The tendon was then passed through the bone tunnel in an anterior-to-posterior direction, and the limbs of the suture were tied around the lateral cortex. 

The process was repeated for animals undergoing diaphyseal tenodesis; only the tenodesis location was different. The inferior border of the pectoralis major was identified, and a bicortical tunnel was made in the center of the diaphyseal bone. The tendon was then prepared and tenodesed to bone using the method already described.

In soft-tissue tenodesis, the conjoint tendon was identified and carefully dissected from surrounding tissues. The LHBT was then tenodesed to the attached conjoint tendon with interrupted simple stitches of 5-0 polypropylene suture.

The animals were allowed to bear weight on the operative limb immediately after surgery and without immobilization.

Specimen Harvest and Preparation

Four animals from each group were sacrificed at 6, 12, and 24 weeks. Harvested specimens were fixed in 10% neutral-buffered formalin solution. Bony specimens consisted of the upper half of the humerus and the tenodesed biceps tendon, and soft-tissue specimens consisted of the tenodesed LHBT-conjoint tendon complex. Bony specimens were decalcified in 10% ethylenediaminetetraacetic acid. All specimens were paraffin-embedded and sectioned at 7 microns.

Analysis of Cellularity

Sections were stained with hematoxylin-eosin. Overall cellularity at the tenodesis interface was quantified by averaging the nuclei count within 3 separate standardized ×20 magnification high power fields. Only nucleated cells were included in the cell count. Immunohistochemical staining with tenomodulin (Santa Cruz Laboratories, sc-49324) was performed to characterize the cell population at the interface. Deparaffinized sections underwent antigen retrieval with pronase for 30 minutes at 37°C and were incubated overnight with the anti-tenomodulin goat monoclonal antibody diluted to 1:200 in 1% phosphate-buffered saline. The prepared slides were then counterstained with methyl green. Specimens treated with tenomodulin were evaluated for presence or absence of a positive reaction at the tenodesis interface. 

Analysis of Inflammation

Inflammation at the interface was evaluated with the CD68 macrophage marker (ABcam, ab31630). Deparaffinized sections underwent antigen retrieval with pronase for 30 minutes at 37°C and were incubated overnight with anti-CD68 mouse monoclonal antibodies diluted to 1:200 in 1% phosphate-buffered saline. The prepared slides were then counterstained with neutral red. Inflammation was quantified by averaging the number of reactive cells within 3 separate standardized ×20 magnification high power fields.

Statistical Analysis

Descriptive statistics were calculated for cell and macrophage counts for each group at every time point. Two-way analysis of variance was used to compare the cell and macrophage counts between groups at each time point as well as the count differences within each group between time points. P values were Bonferroni-corrected to account for the multiple comparisons between groups. P < .05 was used to signify statistical significance.

Results

All 36 animals survived to their designated harvest time without complications. Twelve specimens were successfully harvested at 6 weeks and another 12 at 24 weeks. At 12 weeks, tenodesis failure occurred in 1 animal in group D, leaving 11 specimens for analysis.

Cellularity

Within-group analysis revealed a trend of increasing cellularity at 12 weeks followed by a decrease at 24 weeks in all 3 groups (Table 2).

Inflammatory Response 

During specimen processing, 1 group D specimen was severely degraded after pronase treatment, leaving 3 specimens for evaluation. Descriptive statistics for each group are listed in Table 3A.

At 6 weeks, mean CD68 cell count was significantly higher in group M than in group D (P = .011) and group T (P < .001) (Table 3B). Likewise, CD68 count was significantly higher in group D than in group T (P < .001). There were no differences in CD68 counts between the 2 bony tenodesis groups at 12 weeks (P = .486) or 24 weeks (P = .315). Both bony tenodesis groups, however, had persistently higher CD68 counts at 12 weeks when compared with group T (group M, P = .002; group D, P < .001). In these specimens, an inflammatory milieu characterized by a large accumulation of lymphocytes and giant cells was noted at the bone-tendon interface.

Tissue-Specific Staining

At 6 weeks, antigen retrieval resulted in severe degradation of 2 group M specimens, 2 group D specimens, and 1 group T specimen. The most notable tenomodulin reaction occurred in group T at the 6- and 12-week harvests, with the 6-week group having the most robust reaction. There was scant reaction in this group at 24 weeks.

Discussion

In this study, the healing response differed between bony and soft-tissue tenodesis techniques in a rat model. Tendon-to-bone tenodesis, both diaphyseal and metaphyseal, appeared to incite an inflammatory degenerative response, whereas tendon-to-tendon healing occurred in a more quiescent and perhaps even regenerative manner.

The early inflammatory response that occurred in the bony tenodesis groups is not unlike what occurs in fracture healing.²⁷ The reaction was even more robust at 12 weeks, signifying an ongoing inflammatory process. In this context, tendon degeneration may plausibly explain the consistent absence of mature tendon within the tunnels at all 3 time points. Some tendon degeneration may be explained by the vascular damage that occurred during surgery, but this damage was a constant factor in all 3 study groups. Interestingly, group M showed the highest early CD68 counts, consistent with this being the more biologically active region of bone.²⁸

Group T had significantly lower cell and macrophage counts throughout the study period, possibly indicating improved healing—an observation supported by a study in which the impact of macrophage depletion on bone-tendon interface healing was evaluated.²⁹ The authors found that, in suppressing macrophage activity, the morphologic and biomechanical properties at the healing interface were significantly improved.²⁹ These findings are consistent with Dr. O’Brien’s anecdotal experience with patients who previously underwent the biceps transfer; on second-look arthroscopy, there was complete seamless integration of tendon and conjoint tendon (Figure 4). 

Studies have found that the inflammatory process is closely associated with pain, and pain syndromes such as fibromyalgia.^30,31 Persistent inflammation, as seen in our bony tenodesis group, could explain the recalcitrant anterior shoulder pain that often occurs in patients after bony tenodesis of the LHBT.^2,6,19,32 

Studies have also suggested that osteoclasts at the bone-tendon interface—osteoclasts share a cell lineage with macrophages—may contribute to bone loss and tunnel widening.^33,34 Osteoclasts are expected at the bone tunnel, as fracture healing occurs at the bone-tendon interface. These osteoclasts could have contributed to the strong CD68 reaction in our bony tenodesis groups. However, CD68 historically has been described as the classic macrophage marker.³⁵ We specifically selected CD68 for this reason: Macrophages are the primary inflammatory cells involved in early healing and are key to the inflammatory process.³⁶

Results of the tenomodulin analysis suggested 2 different healing processes are occurring in the bony and tendon groups. Tenomodulin is a known tenocyte marker for developing and mature tendon in both rats and humans.^37,38 In our study, only group T had a positive tenomodulin reaction. Notably, the reaction occurred only at 6 and 12 weeks. This finding may indicate that a regenerative healing pattern becomes quiescent by 24 weeks. Indeed, it has been suggested that tenomodulin is a key regulator of tenocyte proliferation and tendon maturation.³⁹

The complete absence of tenomodulin reaction in our bony tenodesis groups in the setting of significant inflammation further supports our theory of tendon degeneration within the tunnel. One potential explanation for this finding may be that as the tendon heals to the surface of the bone, the intra-osseous tendon is no longer load-bearing and is resorbed by the body through an inflammatory response. This finding differs from those in previous studies, which have described viable tendon within the bone tunnel at all time points up to 26 weeks.⁴⁰ More recently, it has been suggested that callus formation at the external cortical tendon-bone interface is critical for healing and mechanical strength.^41,42 In addition, recent studies have found a predominantly fibroblastic healing process at the midtunnel, potentially leading to the formation of loose fibrovascular tissue at the tendon-bone interface.⁴³ These data, in concert with ours, call into question the rationale for performing intra-osseous tenodesis through bone tunnels.

Our study results, if confirmed in humans, will have significant clinical implications. If a similar effect can be confirmed in the human shoulder, one could argue that soft-tissue tenodesis may result in decreased postoperative shoulder pain. In addition, if tendon degeneration does occur within the intramedullary tunnel, surface fixation may be the better, safer alternative. Although older studies reported suboptimal strength with this type of fixation,^8,44 more recent studies have found surface fixation strength equivalent to screw fixation strength.^45,46 Such a shift in the treatment paradigm would obviate the need for violation of the humeral cortex, eliminating potential stress risers associated with screw fixation,⁴⁷ and effectively eliminating the risk of iatrogenic fracture.^48,49 It would be interesting to investigate what occurs histologically at the bone-tendon interface in surface fixation (ie, suture anchors). Would the inflammatory response at the surface be similar to the inflammatory intramedullary healing, or would it be similar to the quieter tendon-tendon healing? Answers to such questions have the potential to streamline the treatment algorithm for patients who require tenodesis.

Study Limitations

Our study had several limitations. First, as this was a basic science study using a rat model, its conclusions can only be extrapolated to humans. Second, given the nonspecific nature of the cellular analysis, we cannot draw any definitive conclusions about the cell population at the bone-tendon interface. For example, although tenomodulin is expressed by tenocytes, it is not an established specific marker for tenocytes and may be expressed by other fibroblastic cells. Still, our results provide insight into the local microenvironment and identify important differences between the tenodesis methods. Similarly, the complete absence of tendon within the bone tunnels suggests that an analysis of osteoclastic activity at the tenodesis interface may have been a valuable addition to the study. This finding, however, was unexpected, and we did not have the foresight to include it in our methods. A third limitation is that our fixation method essentially uses the suspension tenodesis method. This fixation method differs from the common fixation techniques used in the clinical setting. Testing of other fixation constructs would require a larger animal model. Furthermore, in suspension- type constructs, micromotion within the bone tunnel may independently elicit an inflammatory response. Inert suture was used in our fixation in order to reduce the risk of an iatrogenic inflammatory response. Last, it would have been valuable to perform a biomechanical analysis of the strength of each tenodesis construct. This was explored with our institution’s biomechanics team, but specimen size precluded successful analysis.

Conclusion

Our results indicated that, compared with tendon-to-tendon fixation, tendon-to-bone tenodesis produces a significantly greater inflammatory response at the tenodesis interface. An inflammatory milieu in the absence of tendon within the bony tunnel suggests intraosseous tendon degeneration. Tendon-to-tendon tenodesis, on the other hand, seems to limit the inflammatory response. In addition, a robust tenomodulin reaction in the early phases of tendon-to-tendon healing suggests regenerative healing. Our results showed a fundamental difference in the healing response between the 2 tenodesis methods. Further study is needed to evaluate the validity and applicability of our findings to the human patient population. Most important, our results underscore the need for more study to elucidate optimal tenodesis location and encourage orthopedic surgeons to reexamine current clinical practice patterns.