Orthopedics

Distal radius fracture is a common injury treated by orthopedic surgeons. Fifty percent or more of distal radius fractures (DRFs) occur with concomitant ulnar styloid fractures (USFs)^1-3 (Figure). The base of the ulnar styloid is the insertion site for portions of the triangular fibrocartilaginous complex (TFCC), which is a primary stabilizer of the distal radioulnar joint (DRUJ).^4,5

Although the topic has received significant attention in the literature, there remains a lack of consensus on the prognostic and clinical significance of USF occurring with DRF. In a series reported by May and colleagues,⁶ all patients with DRUJ instability after DRF also had an USF. Some authors have reported USF as a poor prognostic indicator for DRF, as the occurrence of USF was taken as a proxy for DRUJ instability.^7,8 Conversely, other authors have reported that USF nonunion has no effect on the outcome of volar plating of DRF.^9-11 In a retrospective cohort study of 182 patients, Li and colleagues¹² found no clinically significant difference in outcome between presence or absence of USF with DRF. They also reported that the quality of the DRF reduction was the main determinant of clinical outcome in patients with USF.

We examined a large cohort of patients treated for DRF to identify any possible effect of an associated USF on clinical outcome. All patients provided written informed consent for study inclusion.

Materials and Methods

We retrospectively evaluated 315 cases of DRFs treated (184 operatively, 131 nonoperatively) by members of the Trauma and Hand divisions at our institution over a 7-year period. All cases had sufficient follow-up. In each group, patients with concomitant USF were identified.

At presentation, all displaced fractures underwent closed reduction and immobilization with a sugar-tong splint. Baseline demographic data, injury information, and baseline functional scores on the Disabilities of the Arm, Shoulder, and Hand (DASH) questionnaire and the 36-Item Short Form Health Survey (SF-36) were recorded. Complete histories were taken and physical examinations performed. Standard radiographs of the injured and contralateral wrists were obtained at time of initial injury.¹³

Surgery was indicated in patients with an open fracture and in patients with an inherently unstable fracture pattern, using the instability criteria of Cooney and colleagues.¹⁴ According to these criteria, unstable fractures have lost alignment after closed reduction or have more than 20° of dorsal angulation, more than 10 mm of longitudinal shortening, or more than 2 mm of articular displacement.¹⁴ Patients were treated with either a volar locked plate or bridging external fixation with supplemental Kirschner-wire fixation (usually 2 or 3 wires). Patients in both groups (operative, nonoperative) participated in a formal outpatient therapy program that emphasized active and passive range of motion (ROM) of the finger, wrist motion (if clinically appropriate), and forearm motion. Mean clinical follow-up was 12 months (range, 8-18 months). At each clinic visit, we used a handheld dynamometer to measure ROM, grip strength, and other parameters and compared them with the same parameters on the uninjured side, along with functional outcome.

Differences in demographic characteristics were evaluated with 2 tests—the χ² test for categorical variables (eg, USF incidence, sex, hand dominance, fracture pattern) and the Student t test for continuous variables. Mann-Whitney U tests were used to assess differences between groups in DASH and SF-36 scores at long-term follow-up, as well as differences in ROM and radiographic measurements. Statistical significance was set at P < .05.

Results

DRFs occurred in the dominant-side wrist more commonly (P < .05) in the nonoperative group than in the operative group, though there was no difference in hand dominance and presence or absence of USF. There was a significant correlation of intra-articular fractures in the operative group (70%) compared with the nonoperative group (34%), though no association was found between presence of USF and intra-articular fracture location.

The percentage of concomitant USF was higher (P< .0002) in patients treated operatively (64.1%) than in those treated nonoperatively (38.9%). Mean (SD) pain score was higher (P = .0001) for patients with USF, 1.80 (2.43), than for patients without USF, 0.80 (1.55). This relationship held in both the operative group, 1.95 (2.48) versus 1.04 (1.58) (P = .027), and the nonoperative group, 1.29 (2.09) versus 0.66 (1.53) (P = .048). Similarly, at long-term follow-up for the entire patient cohort, mean (SD) DASH score was negatively affected by presence of USF, 17.03 (18.94) versus 9.21 (14.06) (P = .001), as was mean (SD) SF-36 score, 77.16 (17.69) versus 82.68 (16.10) (P = .022). This relationship also held in the operative and nonoperative groups with respect to pain and DASH scores, though there were only trends in this direction with respect to SF-36 scores. At final follow-up, there was no significant correlation of pain, SF-36, or DASH scores with presence of an intra-articular fracture as compared with an extra-articular fracture.

Time to radiographic healing was not influenced by presence of USF compared with absence of USF (11 vs 10.06 weeks; P > .05). Similarly, healing was no different in intra-articular fractures compared with extra-articular fractures (11 vs 10 weeks; P > .05).

Wrist ROM at final follow-up was not affected by presence of USF; there was no significant difference in wrist flexion, extension, or forearm rotation. In addition, mean (SD) grip strength was unaffected (P = .132) by presence or absence of USF with DRF overall, 45.45% (31.92) of contralateral versus 52.88% (30.03). However, grip strength was negatively affected (P = .035) by presence of USF in the nonoperative group, 37.79% (20.58) versus 54.52% (31.89) (Table).

Discussion

In this study, we determined that presence of USF was a negative predictor for clinical outcomes after DRF. Given the higher incidence of USF in operatively treated DRFs, USF likely represents a higher-energy mechanism of injury. We think these inferior clinical results are attributable to other wrist pathologies that commonly occur with these injuries. These pathologies, identified in the past, include stylocarpal impaction, extensor carpi ulnaris tendinitis, and pain at USF site.^6,10,15 In addition, intracarpal ligamentous injuries, including damage to scapholunate and lunotriquetral ligaments, have been shown to occur in roughly 80% of patients who sustain DRFs, with TFCC injuries occurring at a rate of 60%.¹⁶

Patient outcome is multifactorial and depends on initial injury characteristics, reduction quality, associated injuries, and patient demographics and lifestyle factors. Li and colleagues¹² showed that the quality of the DRF reduction influenced outcomes in these injuries, as the ulnar styloid and its associated TFCC are in turn reduced more anatomically with a restored DRF reduction. This concept applies to injuries treated both operatively and nonoperatively. Similarly, Xarchas and colleagues¹⁷ identified malunion of the ulnar styloid as causing chronic wrist pain because of triquetral impingement, which was treated successfully with ulnar styloidectomy. The poor results at final follow-up in their study may reflect severity of the initial injury, as reported by Frykman.¹⁸

Additional factors may compromise clinical outcomes after such injuries. For example, the effect of USF fragment size on outcome has been suggested and debated. In a retrospective series, May and colleagues⁶ identified fractures involving the base of the ulnar styloid or fovea as potentially destabilizing the DRUJ and in turn leading to chronic instability. This mechanism should be considered a potential contributor to protracted clinical recovery. Other studies have shown that, irrespective of USF fragment size, presence of USF with DRF is not a reliable predictor of DRUJ instability.^2,10,19 In the present study, we simply identified presence or absence of USF, irrespective of either stability or fragment size. In cases in which there was an USF without instability, we fixed the DRF in isolation, without surgically addressing the USF. Our data demonstrated that, even in the absence of DRUJ instability, presence of USF was a negative prognostic indicator for patient outcome.

This study had several limitations. First, its design was retrospective. A prospective study would have been ideal for eliminating certain inherent bias. Second, USF represents a higher association with DRUJ instability.⁶ As there are no validated tests for this clinical entity, identification is somewhat subjective. We did not separate patients by presence or absence of DRUJ instability and thus were not able to directly correlate the connection between USF, DRUJ instability, and poor outcomes in association with DRF. In addition, management of an unstable DRUJ after operative fixation of DRF is controversial, with techniques ranging from splinting in supination to pinning the DRUJ. This inconsistency likely contributed to some error between groups of patients in this study. Last, we did not stratify patients by USF fragment size, as previously discussed, which may have affected outcomes within patient groups.

Our data add to the evidence showing that USF in association with DRF portends poorer clinical outcomes. Concomitant USF should alert the treating physician to a higher-energy mechanism of injury and raise the index of suspicion for other associated injuries in the carpus.

Distal radius fracture is a common injury treated by orthopedic surgeons. Fifty percent or more of distal radius fractures (DRFs) occur with concomitant ulnar styloid fractures (USFs)^1-3 (Figure). The base of the ulnar styloid is the insertion site for portions of the triangular fibrocartilaginous complex (TFCC), which is a primary stabilizer of the distal radioulnar joint (DRUJ).^4,5

Although the topic has received significant attention in the literature, there remains a lack of consensus on the prognostic and clinical significance of USF occurring with DRF. In a series reported by May and colleagues,⁶ all patients with DRUJ instability after DRF also had an USF. Some authors have reported USF as a poor prognostic indicator for DRF, as the occurrence of USF was taken as a proxy for DRUJ instability.^7,8 Conversely, other authors have reported that USF nonunion has no effect on the outcome of volar plating of DRF.^9-11 In a retrospective cohort study of 182 patients, Li and colleagues¹² found no clinically significant difference in outcome between presence or absence of USF with DRF. They also reported that the quality of the DRF reduction was the main determinant of clinical outcome in patients with USF.

We examined a large cohort of patients treated for DRF to identify any possible effect of an associated USF on clinical outcome. All patients provided written informed consent for study inclusion.

Materials and Methods

We retrospectively evaluated 315 cases of DRFs treated (184 operatively, 131 nonoperatively) by members of the Trauma and Hand divisions at our institution over a 7-year period. All cases had sufficient follow-up. In each group, patients with concomitant USF were identified.

At presentation, all displaced fractures underwent closed reduction and immobilization with a sugar-tong splint. Baseline demographic data, injury information, and baseline functional scores on the Disabilities of the Arm, Shoulder, and Hand (DASH) questionnaire and the 36-Item Short Form Health Survey (SF-36) were recorded. Complete histories were taken and physical examinations performed. Standard radiographs of the injured and contralateral wrists were obtained at time of initial injury.¹³

Surgery was indicated in patients with an open fracture and in patients with an inherently unstable fracture pattern, using the instability criteria of Cooney and colleagues.¹⁴ According to these criteria, unstable fractures have lost alignment after closed reduction or have more than 20° of dorsal angulation, more than 10 mm of longitudinal shortening, or more than 2 mm of articular displacement.¹⁴ Patients were treated with either a volar locked plate or bridging external fixation with supplemental Kirschner-wire fixation (usually 2 or 3 wires). Patients in both groups (operative, nonoperative) participated in a formal outpatient therapy program that emphasized active and passive range of motion (ROM) of the finger, wrist motion (if clinically appropriate), and forearm motion. Mean clinical follow-up was 12 months (range, 8-18 months). At each clinic visit, we used a handheld dynamometer to measure ROM, grip strength, and other parameters and compared them with the same parameters on the uninjured side, along with functional outcome.

Differences in demographic characteristics were evaluated with 2 tests—the χ² test for categorical variables (eg, USF incidence, sex, hand dominance, fracture pattern) and the Student t test for continuous variables. Mann-Whitney U tests were used to assess differences between groups in DASH and SF-36 scores at long-term follow-up, as well as differences in ROM and radiographic measurements. Statistical significance was set at P < .05.

Results

DRFs occurred in the dominant-side wrist more commonly (P < .05) in the nonoperative group than in the operative group, though there was no difference in hand dominance and presence or absence of USF. There was a significant correlation of intra-articular fractures in the operative group (70%) compared with the nonoperative group (34%), though no association was found between presence of USF and intra-articular fracture location.

The percentage of concomitant USF was higher (P< .0002) in patients treated operatively (64.1%) than in those treated nonoperatively (38.9%). Mean (SD) pain score was higher (P = .0001) for patients with USF, 1.80 (2.43), than for patients without USF, 0.80 (1.55). This relationship held in both the operative group, 1.95 (2.48) versus 1.04 (1.58) (P = .027), and the nonoperative group, 1.29 (2.09) versus 0.66 (1.53) (P = .048). Similarly, at long-term follow-up for the entire patient cohort, mean (SD) DASH score was negatively affected by presence of USF, 17.03 (18.94) versus 9.21 (14.06) (P = .001), as was mean (SD) SF-36 score, 77.16 (17.69) versus 82.68 (16.10) (P = .022). This relationship also held in the operative and nonoperative groups with respect to pain and DASH scores, though there were only trends in this direction with respect to SF-36 scores. At final follow-up, there was no significant correlation of pain, SF-36, or DASH scores with presence of an intra-articular fracture as compared with an extra-articular fracture.

Time to radiographic healing was not influenced by presence of USF compared with absence of USF (11 vs 10.06 weeks; P > .05). Similarly, healing was no different in intra-articular fractures compared with extra-articular fractures (11 vs 10 weeks; P > .05).

Wrist ROM at final follow-up was not affected by presence of USF; there was no significant difference in wrist flexion, extension, or forearm rotation. In addition, mean (SD) grip strength was unaffected (P = .132) by presence or absence of USF with DRF overall, 45.45% (31.92) of contralateral versus 52.88% (30.03). However, grip strength was negatively affected (P = .035) by presence of USF in the nonoperative group, 37.79% (20.58) versus 54.52% (31.89) (Table).

Discussion

In this study, we determined that presence of USF was a negative predictor for clinical outcomes after DRF. Given the higher incidence of USF in operatively treated DRFs, USF likely represents a higher-energy mechanism of injury. We think these inferior clinical results are attributable to other wrist pathologies that commonly occur with these injuries. These pathologies, identified in the past, include stylocarpal impaction, extensor carpi ulnaris tendinitis, and pain at USF site.^6,10,15 In addition, intracarpal ligamentous injuries, including damage to scapholunate and lunotriquetral ligaments, have been shown to occur in roughly 80% of patients who sustain DRFs, with TFCC injuries occurring at a rate of 60%.¹⁶

Patient outcome is multifactorial and depends on initial injury characteristics, reduction quality, associated injuries, and patient demographics and lifestyle factors. Li and colleagues¹² showed that the quality of the DRF reduction influenced outcomes in these injuries, as the ulnar styloid and its associated TFCC are in turn reduced more anatomically with a restored DRF reduction. This concept applies to injuries treated both operatively and nonoperatively. Similarly, Xarchas and colleagues¹⁷ identified malunion of the ulnar styloid as causing chronic wrist pain because of triquetral impingement, which was treated successfully with ulnar styloidectomy. The poor results at final follow-up in their study may reflect severity of the initial injury, as reported by Frykman.¹⁸

Additional factors may compromise clinical outcomes after such injuries. For example, the effect of USF fragment size on outcome has been suggested and debated. In a retrospective series, May and colleagues⁶ identified fractures involving the base of the ulnar styloid or fovea as potentially destabilizing the DRUJ and in turn leading to chronic instability. This mechanism should be considered a potential contributor to protracted clinical recovery. Other studies have shown that, irrespective of USF fragment size, presence of USF with DRF is not a reliable predictor of DRUJ instability.^2,10,19 In the present study, we simply identified presence or absence of USF, irrespective of either stability or fragment size. In cases in which there was an USF without instability, we fixed the DRF in isolation, without surgically addressing the USF. Our data demonstrated that, even in the absence of DRUJ instability, presence of USF was a negative prognostic indicator for patient outcome.

This study had several limitations. First, its design was retrospective. A prospective study would have been ideal for eliminating certain inherent bias. Second, USF represents a higher association with DRUJ instability.⁶ As there are no validated tests for this clinical entity, identification is somewhat subjective. We did not separate patients by presence or absence of DRUJ instability and thus were not able to directly correlate the connection between USF, DRUJ instability, and poor outcomes in association with DRF. In addition, management of an unstable DRUJ after operative fixation of DRF is controversial, with techniques ranging from splinting in supination to pinning the DRUJ. This inconsistency likely contributed to some error between groups of patients in this study. Last, we did not stratify patients by USF fragment size, as previously discussed, which may have affected outcomes within patient groups.

Our data add to the evidence showing that USF in association with DRF portends poorer clinical outcomes. Concomitant USF should alert the treating physician to a higher-energy mechanism of injury and raise the index of suspicion for other associated injuries in the carpus.

Distal radius fracture is a common injury treated by orthopedic surgeons. Fifty percent or more of distal radius fractures (DRFs) occur with concomitant ulnar styloid fractures (USFs)^1-3 (Figure). The base of the ulnar styloid is the insertion site for portions of the triangular fibrocartilaginous complex (TFCC), which is a primary stabilizer of the distal radioulnar joint (DRUJ).^4,5

Although the topic has received significant attention in the literature, there remains a lack of consensus on the prognostic and clinical significance of USF occurring with DRF. In a series reported by May and colleagues,⁶ all patients with DRUJ instability after DRF also had an USF. Some authors have reported USF as a poor prognostic indicator for DRF, as the occurrence of USF was taken as a proxy for DRUJ instability.^7,8 Conversely, other authors have reported that USF nonunion has no effect on the outcome of volar plating of DRF.^9-11 In a retrospective cohort study of 182 patients, Li and colleagues¹² found no clinically significant difference in outcome between presence or absence of USF with DRF. They also reported that the quality of the DRF reduction was the main determinant of clinical outcome in patients with USF.

We examined a large cohort of patients treated for DRF to identify any possible effect of an associated USF on clinical outcome. All patients provided written informed consent for study inclusion.

Materials and Methods

We retrospectively evaluated 315 cases of DRFs treated (184 operatively, 131 nonoperatively) by members of the Trauma and Hand divisions at our institution over a 7-year period. All cases had sufficient follow-up. In each group, patients with concomitant USF were identified.

At presentation, all displaced fractures underwent closed reduction and immobilization with a sugar-tong splint. Baseline demographic data, injury information, and baseline functional scores on the Disabilities of the Arm, Shoulder, and Hand (DASH) questionnaire and the 36-Item Short Form Health Survey (SF-36) were recorded. Complete histories were taken and physical examinations performed. Standard radiographs of the injured and contralateral wrists were obtained at time of initial injury.¹³

Surgery was indicated in patients with an open fracture and in patients with an inherently unstable fracture pattern, using the instability criteria of Cooney and colleagues.¹⁴ According to these criteria, unstable fractures have lost alignment after closed reduction or have more than 20° of dorsal angulation, more than 10 mm of longitudinal shortening, or more than 2 mm of articular displacement.¹⁴ Patients were treated with either a volar locked plate or bridging external fixation with supplemental Kirschner-wire fixation (usually 2 or 3 wires). Patients in both groups (operative, nonoperative) participated in a formal outpatient therapy program that emphasized active and passive range of motion (ROM) of the finger, wrist motion (if clinically appropriate), and forearm motion. Mean clinical follow-up was 12 months (range, 8-18 months). At each clinic visit, we used a handheld dynamometer to measure ROM, grip strength, and other parameters and compared them with the same parameters on the uninjured side, along with functional outcome.

Differences in demographic characteristics were evaluated with 2 tests—the χ² test for categorical variables (eg, USF incidence, sex, hand dominance, fracture pattern) and the Student t test for continuous variables. Mann-Whitney U tests were used to assess differences between groups in DASH and SF-36 scores at long-term follow-up, as well as differences in ROM and radiographic measurements. Statistical significance was set at P < .05.

Results

DRFs occurred in the dominant-side wrist more commonly (P < .05) in the nonoperative group than in the operative group, though there was no difference in hand dominance and presence or absence of USF. There was a significant correlation of intra-articular fractures in the operative group (70%) compared with the nonoperative group (34%), though no association was found between presence of USF and intra-articular fracture location.

The percentage of concomitant USF was higher (P< .0002) in patients treated operatively (64.1%) than in those treated nonoperatively (38.9%). Mean (SD) pain score was higher (P = .0001) for patients with USF, 1.80 (2.43), than for patients without USF, 0.80 (1.55). This relationship held in both the operative group, 1.95 (2.48) versus 1.04 (1.58) (P = .027), and the nonoperative group, 1.29 (2.09) versus 0.66 (1.53) (P = .048). Similarly, at long-term follow-up for the entire patient cohort, mean (SD) DASH score was negatively affected by presence of USF, 17.03 (18.94) versus 9.21 (14.06) (P = .001), as was mean (SD) SF-36 score, 77.16 (17.69) versus 82.68 (16.10) (P = .022). This relationship also held in the operative and nonoperative groups with respect to pain and DASH scores, though there were only trends in this direction with respect to SF-36 scores. At final follow-up, there was no significant correlation of pain, SF-36, or DASH scores with presence of an intra-articular fracture as compared with an extra-articular fracture.

Time to radiographic healing was not influenced by presence of USF compared with absence of USF (11 vs 10.06 weeks; P > .05). Similarly, healing was no different in intra-articular fractures compared with extra-articular fractures (11 vs 10 weeks; P > .05).

Wrist ROM at final follow-up was not affected by presence of USF; there was no significant difference in wrist flexion, extension, or forearm rotation. In addition, mean (SD) grip strength was unaffected (P = .132) by presence or absence of USF with DRF overall, 45.45% (31.92) of contralateral versus 52.88% (30.03). However, grip strength was negatively affected (P = .035) by presence of USF in the nonoperative group, 37.79% (20.58) versus 54.52% (31.89) (Table).

Discussion

In this study, we determined that presence of USF was a negative predictor for clinical outcomes after DRF. Given the higher incidence of USF in operatively treated DRFs, USF likely represents a higher-energy mechanism of injury. We think these inferior clinical results are attributable to other wrist pathologies that commonly occur with these injuries. These pathologies, identified in the past, include stylocarpal impaction, extensor carpi ulnaris tendinitis, and pain at USF site.^6,10,15 In addition, intracarpal ligamentous injuries, including damage to scapholunate and lunotriquetral ligaments, have been shown to occur in roughly 80% of patients who sustain DRFs, with TFCC injuries occurring at a rate of 60%.¹⁶

Patient outcome is multifactorial and depends on initial injury characteristics, reduction quality, associated injuries, and patient demographics and lifestyle factors. Li and colleagues¹² showed that the quality of the DRF reduction influenced outcomes in these injuries, as the ulnar styloid and its associated TFCC are in turn reduced more anatomically with a restored DRF reduction. This concept applies to injuries treated both operatively and nonoperatively. Similarly, Xarchas and colleagues¹⁷ identified malunion of the ulnar styloid as causing chronic wrist pain because of triquetral impingement, which was treated successfully with ulnar styloidectomy. The poor results at final follow-up in their study may reflect severity of the initial injury, as reported by Frykman.¹⁸

Additional factors may compromise clinical outcomes after such injuries. For example, the effect of USF fragment size on outcome has been suggested and debated. In a retrospective series, May and colleagues⁶ identified fractures involving the base of the ulnar styloid or fovea as potentially destabilizing the DRUJ and in turn leading to chronic instability. This mechanism should be considered a potential contributor to protracted clinical recovery. Other studies have shown that, irrespective of USF fragment size, presence of USF with DRF is not a reliable predictor of DRUJ instability.^2,10,19 In the present study, we simply identified presence or absence of USF, irrespective of either stability or fragment size. In cases in which there was an USF without instability, we fixed the DRF in isolation, without surgically addressing the USF. Our data demonstrated that, even in the absence of DRUJ instability, presence of USF was a negative prognostic indicator for patient outcome.

This study had several limitations. First, its design was retrospective. A prospective study would have been ideal for eliminating certain inherent bias. Second, USF represents a higher association with DRUJ instability.⁶ As there are no validated tests for this clinical entity, identification is somewhat subjective. We did not separate patients by presence or absence of DRUJ instability and thus were not able to directly correlate the connection between USF, DRUJ instability, and poor outcomes in association with DRF. In addition, management of an unstable DRUJ after operative fixation of DRF is controversial, with techniques ranging from splinting in supination to pinning the DRUJ. This inconsistency likely contributed to some error between groups of patients in this study. Last, we did not stratify patients by USF fragment size, as previously discussed, which may have affected outcomes within patient groups.

Our data add to the evidence showing that USF in association with DRF portends poorer clinical outcomes. Concomitant USF should alert the treating physician to a higher-energy mechanism of injury and raise the index of suspicion for other associated injuries in the carpus.

Elbow epicondylitis is a painful condition caused by overuse and development of tendon degeneration. It is one of the most common elbow problems in adults, occurring both laterally and medially. “Tennis elbow” or lateral epicondylitis is diagnosed 7 to 10 times more often than the medial form, “golfer’s elbow.”¹ Although these injuries are often associated with racquet sports, activities such as bowling and weightlifting and the professions of carpentry, plumbing, and meat-cutting have been described as causes.^2,3

Elbow epicondylitis is thought to be the result of multiple microtraumatic events that cause disruption of the internal structure of the tendon and degeneration of the cells and matrix.⁴ Lesions caused by chronic overuse are now commonly called tendinosis and are not considered inflammatory in nature. Although the term tendinitis is used frequently and indiscriminately, histopathologic studies have shown that specimens of tendon obtained from areas of chronic overuse do not contain large numbers of macrophages, lymphocytes, or neutrophils.⁵ Rather, tendinosis appears to be a degenerative process that is characterized by the presence of dense populations of fibroblasts, vascular hyperplasia, and disorganized collagen. This constellation of findings has been termed by some authors as angiofibroblastic hyperplasia.⁶

Conservative care for the treatment of chronic tendinosis has been well described and is often successful. Treatment consists of rest, ice, compression, and elevation in the acute phase. This can be followed with bracing, activity modification, physical therapy, oral nonsteroidal anti-inflammatory drugs, topical applications, and injections of cortisone or platelet-rich plasma. When conservative treatment fails, surgical intervention may be considered. Procedures for the treatment of lateral epicondylitis include open débridement and release, arthroscopic débridement, percutaneous release, and radiofrequency (RF) coblation. The goals of operative treatment are to resect pathological material, to stimulate neovascularization by producing focused local bleeding, and to create a healthy scar while doing the least possible structural damage to surrounding tissues.⁴

The efficacy of a bipolar RF-based approach for using microtenotomy was first recognized when researchers studied the effects of transmyocardial revascularization for treating congestive heart failure.⁷ The use of RF- and laser-based transmyocardial revascularization initiated an angiogenic response in degenerated (ischemic) heart tissue. This success led to investigating the use of a RF-based approach for performing microtenotomy. Preclinical studies demonstrated that RF-based microtenotomy was effective for stimulating an angiogenic-healing response in tendon tissue.⁸ Histologic evaluation of treated tendons showed an early inflammatory response, with new blood-vessel formation by 28 days. In 2005, short-term results of this technique were published.⁹ This preliminary prospective case series showed that the treatment was safe and effectively improved or eliminated clinical symptoms.⁹ In the present midterm study, we hypothesized that pain scores would improve after RF microtenotomy and that these favorable results would continue to be observed over a longer term postoperatively.

Materials and Methods

Patients

This was a prospective, nonrandomized, single-center clinical study. After receiving institutional review board approval, patients who were 18 to 65 years of age with a diagnosis of tendinosis were approached for enrollment. For inclusion, patients had to be symptomatic for at least 6 months and had to have failed extensive conservative treatments. Nonoperative treatment included activity modification, enrollment in a facility- or home-based exercise program, bracing, oral nonsteroidal anti-inflammatory medication, and cortisone injection. Candidates with diabetes, confirmed or suspected pregnancy, surgery in the same tendon, implanted hardware adjacent to the target treatment region, or who were receiving care under workers’ compensation or had litigation-related injury were excluded. A single clinician performed a thorough medical history and clinical evaluation. The clinical follow-up and data collection were performed by an independent medical technician.

Clinical Outcomes

Pain status was assessed by using a visual analog scale (VAS). Postoperative clinical assessment was conducted within the first 2 days; at 7 to 10 days; at 4 to 6 weeks; and at 3, 6, 12, and 24 months, up to 9 years postoperatively. The VAS scales were completed annually up to 9 years after the procedure.

The percent improvement of VAS score was calculated. This value represented the difference between the patient’s preoperative and most recent VAS assessments. Failure of the procedure was defined as less than 50% improvement of the VAS score.

The RF-Based Microtenotomy Device

The Topaz Microdebrider (ArthroCare), connected to a System 2000 generator at setting 4 (175 V-RMS), was used to perform the RF-based microtenotomy. The device uses a controlled plasma-mediated RF-based process (coblation). Radiofrequency energy is used to excite the electrolytes in a conductive medium, such as a saline solution, to create precisely focused plasma. The energized particles in the plasma have sufficient energy to break molecular bonds,^10,11 excising or dissolving (ie, ablating) soft tissue at relatively low temperatures (typically, 40°-70° C).^12,13 The diameter of the active tip of the Topaz device is 0.8 mm.

Surgical Procedure

The senior author performed the majority of procedures in this study. Near the end of the series, the senior author’s associate also performed procedures. The symptomatic area of the tendon was identified and marked while the patient was alert. After the patient was positioned appropriately, light sedation was administered. A tourniquet was placed over the treatment limb and inflated to 250 mm Hg. A small incision, approximately 3 cm in length, was made over the marked treatment site to expose the involved tendon. After initiating sterile isotonic saline flow of 1 drop every 1 to 2 seconds from a line connected to the RF system, the tip of the device was placed on the tendon perpendicular to its surface (Figure 1). Using a light touch, it was activated for 500 milliseconds using a timer accessory for the control box. Five to 8 grams of pressure were applied with the device to penetrate the tendon and achieve successful ablation. The RF applications were performed at 5-mm intervals, to create a grid-like pattern on and throughout the symptomatic tendon area. The tendon was perforated to a depth of several millimeters on every second or third application throughout the treatment grid. After treatment of the symptomatic area, the wound was irrigated with copious amounts of normal saline solution and closed with interrupted nylon suture. Local anesthetic was injected only in the skin and in subcutaneous tissue. Standard wound dressings were applied. In the immediate postoperative period, the patient was advised to begin gentle active and passive range-of-motion exercises. Each patient was evaluated at 1 week postoperatively. At 6 weeks, patients were permitted to increase the intensity of their activities. Return to sports and heavy lifting was allowed once the patient was asymptomatic and had achieved full strength and range of motion; this typically occurred at 6 to 9 weeks after surgery.

Statistical Analysis

Normally distributed data were described using standard parametric statistics (ie, mean and standard deviation); non-normally distributed data were characterized using nonparametric descriptors (ie, median and quartiles). Statistical evaluation of improvement in pain status was performed by calculating 99% confidence intervals and using the Student t test for change between subsequent time points. Use of confidence intervals provides a descriptive analysis of the observed treatment effect, while permitting determination of statistical relevance. In all statistical testing, confidence bounds not including 0 were considered statistically significant. Probability of P ≤ .01 for committing type I experiment-wise error (rejecting a true null hypothesis) was selected for all statistical testing because of our lack of a control group, small sample size, and evaluation of multiple postoperative time points.

Results

Eighty consecutive patients with tendinosis of the elbow were included in this study. Sixty-nine patients were treated for lateral epicondylitis and 11 for medial epicondylitis. The average age of the patients (33 women, 47 men) was 50 years. The duration of follow-up evaluation ranged from 6 months to 9 years (mean, 2.5 years; median, 2 years). The Table presents the VAS improvement for these patients after the RF microtenotomy.

Within the lateral epicondylitis group, 91% (63/69) of the patients reported a successful outcome. The postoperative VAS improved to 1.3 from 6.9, which demonstrated an 81% improvement. Of the 6 patients that did not improve, 2 underwent repeat surgery.

Among the patients treated for medial epicondylitis, 91% (10/11) reported improvement in symptoms. The postoperative VAS improved to 1.3 from 6.1, a 79% improvement. One patient did not improve and did not undergo repeat surgery.

Discussion

For the treatment of medial and lateral elbow epicondylitis, RF microtenotomy is successful in 91% of patients. Symptomatic improvement was observed up to 9 years postoperatively. During this study, no complications were recorded; 7 treatment failures occurred. When compared with other techniques, the results with RF microtenotomy are equivalent or better.

In a retrospective study, Szabo and colleagues¹⁴ compared open, arthroscopic, and percutaneous release for lateral elbow tendinosis. They found the 3 methods to be highly effective for the treatment of tendinosis with no significant difference between them. Resection of the epicondyle and transfer of the anconeus muscle was found to be effective (94%) in a retrospective study by Almquist and colleagues.¹⁵ Dunn and coauthors¹⁶ reported a 97% success rate at 10 to 14 years postoperatively with a mini-open technique. Rubenthaler and colleagues¹⁷ showed 88% effectiveness for the open technique and 93% for the arthroscopic technique. With arthroscopic release of the extensor carpi radialis brevis tendon, Lattermann and coauthors¹⁸ reported clinical improvement in 94% of patients. In a study by Rose and colleagues,¹⁹ denervation of the lateral epicondyle was effective in relieving pain in 80% of patients who had had a positive response to a local anesthetic block. In a recently published study by Koh and coauthors,²⁰ 19 of 20 patients experienced a favorable outcome after treatment with ultrasonic microresection.

Regardless of surgical methods and their reported success rate, complications are associated with elbow surgery. Postoperative problems may include restricted function, elbow instability, persistent muscle weakness, and painful neuroma of the posterior cutaneous nerve.^10,21,22 The recent introduction of arthroscopic release offers the potential for less morbidity and enables visualization of the elbow joint. However, disadvantages of the arthroscopic approach include violation of the joint for extra-articular pathology, increased operative time and cost, and neurovascular complications. Additionally, it is possible that the entire spectrum of extra-articular tendinosis cannot be effectively identified arthroscopically.²³ In a prospective, randomized study, Meknas and colleagues²⁴ compared RF microtenotomy with extensor tendon release and repair. They showed that patients treated with RF-microtenotomy experienced earlier pain relief and improved grip strength over the release group.

Different proposed mechanisms of action have been described to explain the favorable effects of the RF-based microtenotomy procedure, such as induced healing by an angiogenic response in the tendon tissue. In an animal study, Harwood and colleagues⁸ showed that low-dose RF-based plasma microtenotomy has the ability to stimulate angiogenic growth factors in tendons, such as α_v integrin and vascular endothelial growth factor. These factors have been shown to be associated with healing.⁸ Early inflammatory response with new-vessel formation after 28 days was found in another animal study using the same method.²⁵ Evaluation of RF-based methods in a prospective controlled laboratory study using a rabbit-tendon model showed histologic evidence of early inflammation with development of neovasculature after treatment.⁸ A later histologic study using an aged Achilles rabbit tendon model was performed to evaluate the effect of RF-based plasma microtenotomy on collagen remodeling.²⁵ The degenerated tendon showed gaps, few normal crimpings, and a lack of reflectivity under polarized light. At 9 days after treatment, the treated tendon showed localized irregular crimpings, and, at 30 days, it showed regular crimping, tightly dense collagen fibers, and hypercellularity with good reflectivity. This was similar in appearance to a normal nondegenerated tendon (Figures 2A-2D). The RF-treated tendon also demonstrated an increase in production of insulin-like growth factor-1, β-fibroblast growth factor-1, α_v integrin, and vascular endothelial growth factor.

Pathologic nerve ingrowth or nerve irritation in the tendon substance has been considered a possible cause of the pain experienced with tendinosis. Radiofrequency treatment has been shown to induce acute degeneration and ablation of sensory nerve fibers.²⁶ These degenerated nerve fibers were observed to regenerate at 90 days after treatment.²⁷ These findings provide potential evidence for early pain relief that is maintained long term as the nerves regenerate.

This midterm follow-up of patients with elbow epicondylitis has shown that RF-based microtenotomy can produce successful, durable results. Microtenotomy is a technically simple procedure to perform and is associated with a rapid and uncomplicated recovery. It is safe and can effectively eliminate or markedly reduce clinical symptoms.

Limitations

Lateral epicondylitis has been described as a self-limited disease, with resolution of symptoms at 12 to 18 months with conservative treatment. This perspective challenges the indication of any proposed surgical treatment for the condition. Although the results of this research demonstrated the benefits of RF microtenotomy, there are inherent limitations of the study design. The study lacks a control group, and randomization would improve the strength of the study. Additional outcome measures, such as Disabilities of the Arm, Shoulder, and Hand score, and grip strength could complement pain scores to provide more data. These data were collected in a preliminary study.⁹ Postoperative histologic analysis of treated human tissue would be ideal, but ethical considerations limit study to animal models. An additional limitation is potential examiner bias. Data collection was performed by an independent medical technician; a third-party blinded evaluation could have been performed, but this was not feasible in a clinical setting.

Conclusion

Radiofrequency-based microtenotomy is a safe and effective procedure for elbow epicondylitis. The results are durable with successful outcomes observed 9 years after surgery.

Elbow epicondylitis is a painful condition caused by overuse and development of tendon degeneration. It is one of the most common elbow problems in adults, occurring both laterally and medially. “Tennis elbow” or lateral epicondylitis is diagnosed 7 to 10 times more often than the medial form, “golfer’s elbow.”¹ Although these injuries are often associated with racquet sports, activities such as bowling and weightlifting and the professions of carpentry, plumbing, and meat-cutting have been described as causes.^2,3

Elbow epicondylitis is thought to be the result of multiple microtraumatic events that cause disruption of the internal structure of the tendon and degeneration of the cells and matrix.⁴ Lesions caused by chronic overuse are now commonly called tendinosis and are not considered inflammatory in nature. Although the term tendinitis is used frequently and indiscriminately, histopathologic studies have shown that specimens of tendon obtained from areas of chronic overuse do not contain large numbers of macrophages, lymphocytes, or neutrophils.⁵ Rather, tendinosis appears to be a degenerative process that is characterized by the presence of dense populations of fibroblasts, vascular hyperplasia, and disorganized collagen. This constellation of findings has been termed by some authors as angiofibroblastic hyperplasia.⁶

Conservative care for the treatment of chronic tendinosis has been well described and is often successful. Treatment consists of rest, ice, compression, and elevation in the acute phase. This can be followed with bracing, activity modification, physical therapy, oral nonsteroidal anti-inflammatory drugs, topical applications, and injections of cortisone or platelet-rich plasma. When conservative treatment fails, surgical intervention may be considered. Procedures for the treatment of lateral epicondylitis include open débridement and release, arthroscopic débridement, percutaneous release, and radiofrequency (RF) coblation. The goals of operative treatment are to resect pathological material, to stimulate neovascularization by producing focused local bleeding, and to create a healthy scar while doing the least possible structural damage to surrounding tissues.⁴

The efficacy of a bipolar RF-based approach for using microtenotomy was first recognized when researchers studied the effects of transmyocardial revascularization for treating congestive heart failure.⁷ The use of RF- and laser-based transmyocardial revascularization initiated an angiogenic response in degenerated (ischemic) heart tissue. This success led to investigating the use of a RF-based approach for performing microtenotomy. Preclinical studies demonstrated that RF-based microtenotomy was effective for stimulating an angiogenic-healing response in tendon tissue.⁸ Histologic evaluation of treated tendons showed an early inflammatory response, with new blood-vessel formation by 28 days. In 2005, short-term results of this technique were published.⁹ This preliminary prospective case series showed that the treatment was safe and effectively improved or eliminated clinical symptoms.⁹ In the present midterm study, we hypothesized that pain scores would improve after RF microtenotomy and that these favorable results would continue to be observed over a longer term postoperatively.

Materials and Methods

Patients

This was a prospective, nonrandomized, single-center clinical study. After receiving institutional review board approval, patients who were 18 to 65 years of age with a diagnosis of tendinosis were approached for enrollment. For inclusion, patients had to be symptomatic for at least 6 months and had to have failed extensive conservative treatments. Nonoperative treatment included activity modification, enrollment in a facility- or home-based exercise program, bracing, oral nonsteroidal anti-inflammatory medication, and cortisone injection. Candidates with diabetes, confirmed or suspected pregnancy, surgery in the same tendon, implanted hardware adjacent to the target treatment region, or who were receiving care under workers’ compensation or had litigation-related injury were excluded. A single clinician performed a thorough medical history and clinical evaluation. The clinical follow-up and data collection were performed by an independent medical technician.

Clinical Outcomes

Pain status was assessed by using a visual analog scale (VAS). Postoperative clinical assessment was conducted within the first 2 days; at 7 to 10 days; at 4 to 6 weeks; and at 3, 6, 12, and 24 months, up to 9 years postoperatively. The VAS scales were completed annually up to 9 years after the procedure.

The percent improvement of VAS score was calculated. This value represented the difference between the patient’s preoperative and most recent VAS assessments. Failure of the procedure was defined as less than 50% improvement of the VAS score.

The RF-Based Microtenotomy Device

The Topaz Microdebrider (ArthroCare), connected to a System 2000 generator at setting 4 (175 V-RMS), was used to perform the RF-based microtenotomy. The device uses a controlled plasma-mediated RF-based process (coblation). Radiofrequency energy is used to excite the electrolytes in a conductive medium, such as a saline solution, to create precisely focused plasma. The energized particles in the plasma have sufficient energy to break molecular bonds,^10,11 excising or dissolving (ie, ablating) soft tissue at relatively low temperatures (typically, 40°-70° C).^12,13 The diameter of the active tip of the Topaz device is 0.8 mm.

Surgical Procedure

The senior author performed the majority of procedures in this study. Near the end of the series, the senior author’s associate also performed procedures. The symptomatic area of the tendon was identified and marked while the patient was alert. After the patient was positioned appropriately, light sedation was administered. A tourniquet was placed over the treatment limb and inflated to 250 mm Hg. A small incision, approximately 3 cm in length, was made over the marked treatment site to expose the involved tendon. After initiating sterile isotonic saline flow of 1 drop every 1 to 2 seconds from a line connected to the RF system, the tip of the device was placed on the tendon perpendicular to its surface (Figure 1). Using a light touch, it was activated for 500 milliseconds using a timer accessory for the control box. Five to 8 grams of pressure were applied with the device to penetrate the tendon and achieve successful ablation. The RF applications were performed at 5-mm intervals, to create a grid-like pattern on and throughout the symptomatic tendon area. The tendon was perforated to a depth of several millimeters on every second or third application throughout the treatment grid. After treatment of the symptomatic area, the wound was irrigated with copious amounts of normal saline solution and closed with interrupted nylon suture. Local anesthetic was injected only in the skin and in subcutaneous tissue. Standard wound dressings were applied. In the immediate postoperative period, the patient was advised to begin gentle active and passive range-of-motion exercises. Each patient was evaluated at 1 week postoperatively. At 6 weeks, patients were permitted to increase the intensity of their activities. Return to sports and heavy lifting was allowed once the patient was asymptomatic and had achieved full strength and range of motion; this typically occurred at 6 to 9 weeks after surgery.

Statistical Analysis

Normally distributed data were described using standard parametric statistics (ie, mean and standard deviation); non-normally distributed data were characterized using nonparametric descriptors (ie, median and quartiles). Statistical evaluation of improvement in pain status was performed by calculating 99% confidence intervals and using the Student t test for change between subsequent time points. Use of confidence intervals provides a descriptive analysis of the observed treatment effect, while permitting determination of statistical relevance. In all statistical testing, confidence bounds not including 0 were considered statistically significant. Probability of P ≤ .01 for committing type I experiment-wise error (rejecting a true null hypothesis) was selected for all statistical testing because of our lack of a control group, small sample size, and evaluation of multiple postoperative time points.

Results

Eighty consecutive patients with tendinosis of the elbow were included in this study. Sixty-nine patients were treated for lateral epicondylitis and 11 for medial epicondylitis. The average age of the patients (33 women, 47 men) was 50 years. The duration of follow-up evaluation ranged from 6 months to 9 years (mean, 2.5 years; median, 2 years). The Table presents the VAS improvement for these patients after the RF microtenotomy.

Within the lateral epicondylitis group, 91% (63/69) of the patients reported a successful outcome. The postoperative VAS improved to 1.3 from 6.9, which demonstrated an 81% improvement. Of the 6 patients that did not improve, 2 underwent repeat surgery.

Among the patients treated for medial epicondylitis, 91% (10/11) reported improvement in symptoms. The postoperative VAS improved to 1.3 from 6.1, a 79% improvement. One patient did not improve and did not undergo repeat surgery.

Discussion

For the treatment of medial and lateral elbow epicondylitis, RF microtenotomy is successful in 91% of patients. Symptomatic improvement was observed up to 9 years postoperatively. During this study, no complications were recorded; 7 treatment failures occurred. When compared with other techniques, the results with RF microtenotomy are equivalent or better.

In a retrospective study, Szabo and colleagues¹⁴ compared open, arthroscopic, and percutaneous release for lateral elbow tendinosis. They found the 3 methods to be highly effective for the treatment of tendinosis with no significant difference between them. Resection of the epicondyle and transfer of the anconeus muscle was found to be effective (94%) in a retrospective study by Almquist and colleagues.¹⁵ Dunn and coauthors¹⁶ reported a 97% success rate at 10 to 14 years postoperatively with a mini-open technique. Rubenthaler and colleagues¹⁷ showed 88% effectiveness for the open technique and 93% for the arthroscopic technique. With arthroscopic release of the extensor carpi radialis brevis tendon, Lattermann and coauthors¹⁸ reported clinical improvement in 94% of patients. In a study by Rose and colleagues,¹⁹ denervation of the lateral epicondyle was effective in relieving pain in 80% of patients who had had a positive response to a local anesthetic block. In a recently published study by Koh and coauthors,²⁰ 19 of 20 patients experienced a favorable outcome after treatment with ultrasonic microresection.

Regardless of surgical methods and their reported success rate, complications are associated with elbow surgery. Postoperative problems may include restricted function, elbow instability, persistent muscle weakness, and painful neuroma of the posterior cutaneous nerve.^10,21,22 The recent introduction of arthroscopic release offers the potential for less morbidity and enables visualization of the elbow joint. However, disadvantages of the arthroscopic approach include violation of the joint for extra-articular pathology, increased operative time and cost, and neurovascular complications. Additionally, it is possible that the entire spectrum of extra-articular tendinosis cannot be effectively identified arthroscopically.²³ In a prospective, randomized study, Meknas and colleagues²⁴ compared RF microtenotomy with extensor tendon release and repair. They showed that patients treated with RF-microtenotomy experienced earlier pain relief and improved grip strength over the release group.

Different proposed mechanisms of action have been described to explain the favorable effects of the RF-based microtenotomy procedure, such as induced healing by an angiogenic response in the tendon tissue. In an animal study, Harwood and colleagues⁸ showed that low-dose RF-based plasma microtenotomy has the ability to stimulate angiogenic growth factors in tendons, such as α_v integrin and vascular endothelial growth factor. These factors have been shown to be associated with healing.⁸ Early inflammatory response with new-vessel formation after 28 days was found in another animal study using the same method.²⁵ Evaluation of RF-based methods in a prospective controlled laboratory study using a rabbit-tendon model showed histologic evidence of early inflammation with development of neovasculature after treatment.⁸ A later histologic study using an aged Achilles rabbit tendon model was performed to evaluate the effect of RF-based plasma microtenotomy on collagen remodeling.²⁵ The degenerated tendon showed gaps, few normal crimpings, and a lack of reflectivity under polarized light. At 9 days after treatment, the treated tendon showed localized irregular crimpings, and, at 30 days, it showed regular crimping, tightly dense collagen fibers, and hypercellularity with good reflectivity. This was similar in appearance to a normal nondegenerated tendon (Figures 2A-2D). The RF-treated tendon also demonstrated an increase in production of insulin-like growth factor-1, β-fibroblast growth factor-1, α_v integrin, and vascular endothelial growth factor.

Pathologic nerve ingrowth or nerve irritation in the tendon substance has been considered a possible cause of the pain experienced with tendinosis. Radiofrequency treatment has been shown to induce acute degeneration and ablation of sensory nerve fibers.²⁶ These degenerated nerve fibers were observed to regenerate at 90 days after treatment.²⁷ These findings provide potential evidence for early pain relief that is maintained long term as the nerves regenerate.

This midterm follow-up of patients with elbow epicondylitis has shown that RF-based microtenotomy can produce successful, durable results. Microtenotomy is a technically simple procedure to perform and is associated with a rapid and uncomplicated recovery. It is safe and can effectively eliminate or markedly reduce clinical symptoms.

Limitations

Lateral epicondylitis has been described as a self-limited disease, with resolution of symptoms at 12 to 18 months with conservative treatment. This perspective challenges the indication of any proposed surgical treatment for the condition. Although the results of this research demonstrated the benefits of RF microtenotomy, there are inherent limitations of the study design. The study lacks a control group, and randomization would improve the strength of the study. Additional outcome measures, such as Disabilities of the Arm, Shoulder, and Hand score, and grip strength could complement pain scores to provide more data. These data were collected in a preliminary study.⁹ Postoperative histologic analysis of treated human tissue would be ideal, but ethical considerations limit study to animal models. An additional limitation is potential examiner bias. Data collection was performed by an independent medical technician; a third-party blinded evaluation could have been performed, but this was not feasible in a clinical setting.

Conclusion

Radiofrequency-based microtenotomy is a safe and effective procedure for elbow epicondylitis. The results are durable with successful outcomes observed 9 years after surgery.

Elbow epicondylitis is a painful condition caused by overuse and development of tendon degeneration. It is one of the most common elbow problems in adults, occurring both laterally and medially. “Tennis elbow” or lateral epicondylitis is diagnosed 7 to 10 times more often than the medial form, “golfer’s elbow.”¹ Although these injuries are often associated with racquet sports, activities such as bowling and weightlifting and the professions of carpentry, plumbing, and meat-cutting have been described as causes.^2,3

Elbow epicondylitis is thought to be the result of multiple microtraumatic events that cause disruption of the internal structure of the tendon and degeneration of the cells and matrix.⁴ Lesions caused by chronic overuse are now commonly called tendinosis and are not considered inflammatory in nature. Although the term tendinitis is used frequently and indiscriminately, histopathologic studies have shown that specimens of tendon obtained from areas of chronic overuse do not contain large numbers of macrophages, lymphocytes, or neutrophils.⁵ Rather, tendinosis appears to be a degenerative process that is characterized by the presence of dense populations of fibroblasts, vascular hyperplasia, and disorganized collagen. This constellation of findings has been termed by some authors as angiofibroblastic hyperplasia.⁶

Conservative care for the treatment of chronic tendinosis has been well described and is often successful. Treatment consists of rest, ice, compression, and elevation in the acute phase. This can be followed with bracing, activity modification, physical therapy, oral nonsteroidal anti-inflammatory drugs, topical applications, and injections of cortisone or platelet-rich plasma. When conservative treatment fails, surgical intervention may be considered. Procedures for the treatment of lateral epicondylitis include open débridement and release, arthroscopic débridement, percutaneous release, and radiofrequency (RF) coblation. The goals of operative treatment are to resect pathological material, to stimulate neovascularization by producing focused local bleeding, and to create a healthy scar while doing the least possible structural damage to surrounding tissues.⁴

The efficacy of a bipolar RF-based approach for using microtenotomy was first recognized when researchers studied the effects of transmyocardial revascularization for treating congestive heart failure.⁷ The use of RF- and laser-based transmyocardial revascularization initiated an angiogenic response in degenerated (ischemic) heart tissue. This success led to investigating the use of a RF-based approach for performing microtenotomy. Preclinical studies demonstrated that RF-based microtenotomy was effective for stimulating an angiogenic-healing response in tendon tissue.⁸ Histologic evaluation of treated tendons showed an early inflammatory response, with new blood-vessel formation by 28 days. In 2005, short-term results of this technique were published.⁹ This preliminary prospective case series showed that the treatment was safe and effectively improved or eliminated clinical symptoms.⁹ In the present midterm study, we hypothesized that pain scores would improve after RF microtenotomy and that these favorable results would continue to be observed over a longer term postoperatively.

Materials and Methods

Patients

This was a prospective, nonrandomized, single-center clinical study. After receiving institutional review board approval, patients who were 18 to 65 years of age with a diagnosis of tendinosis were approached for enrollment. For inclusion, patients had to be symptomatic for at least 6 months and had to have failed extensive conservative treatments. Nonoperative treatment included activity modification, enrollment in a facility- or home-based exercise program, bracing, oral nonsteroidal anti-inflammatory medication, and cortisone injection. Candidates with diabetes, confirmed or suspected pregnancy, surgery in the same tendon, implanted hardware adjacent to the target treatment region, or who were receiving care under workers’ compensation or had litigation-related injury were excluded. A single clinician performed a thorough medical history and clinical evaluation. The clinical follow-up and data collection were performed by an independent medical technician.

Clinical Outcomes

Pain status was assessed by using a visual analog scale (VAS). Postoperative clinical assessment was conducted within the first 2 days; at 7 to 10 days; at 4 to 6 weeks; and at 3, 6, 12, and 24 months, up to 9 years postoperatively. The VAS scales were completed annually up to 9 years after the procedure.

The percent improvement of VAS score was calculated. This value represented the difference between the patient’s preoperative and most recent VAS assessments. Failure of the procedure was defined as less than 50% improvement of the VAS score.

The RF-Based Microtenotomy Device

The Topaz Microdebrider (ArthroCare), connected to a System 2000 generator at setting 4 (175 V-RMS), was used to perform the RF-based microtenotomy. The device uses a controlled plasma-mediated RF-based process (coblation). Radiofrequency energy is used to excite the electrolytes in a conductive medium, such as a saline solution, to create precisely focused plasma. The energized particles in the plasma have sufficient energy to break molecular bonds,^10,11 excising or dissolving (ie, ablating) soft tissue at relatively low temperatures (typically, 40°-70° C).^12,13 The diameter of the active tip of the Topaz device is 0.8 mm.

Surgical Procedure

The senior author performed the majority of procedures in this study. Near the end of the series, the senior author’s associate also performed procedures. The symptomatic area of the tendon was identified and marked while the patient was alert. After the patient was positioned appropriately, light sedation was administered. A tourniquet was placed over the treatment limb and inflated to 250 mm Hg. A small incision, approximately 3 cm in length, was made over the marked treatment site to expose the involved tendon. After initiating sterile isotonic saline flow of 1 drop every 1 to 2 seconds from a line connected to the RF system, the tip of the device was placed on the tendon perpendicular to its surface (Figure 1). Using a light touch, it was activated for 500 milliseconds using a timer accessory for the control box. Five to 8 grams of pressure were applied with the device to penetrate the tendon and achieve successful ablation. The RF applications were performed at 5-mm intervals, to create a grid-like pattern on and throughout the symptomatic tendon area. The tendon was perforated to a depth of several millimeters on every second or third application throughout the treatment grid. After treatment of the symptomatic area, the wound was irrigated with copious amounts of normal saline solution and closed with interrupted nylon suture. Local anesthetic was injected only in the skin and in subcutaneous tissue. Standard wound dressings were applied. In the immediate postoperative period, the patient was advised to begin gentle active and passive range-of-motion exercises. Each patient was evaluated at 1 week postoperatively. At 6 weeks, patients were permitted to increase the intensity of their activities. Return to sports and heavy lifting was allowed once the patient was asymptomatic and had achieved full strength and range of motion; this typically occurred at 6 to 9 weeks after surgery.

Statistical Analysis

Normally distributed data were described using standard parametric statistics (ie, mean and standard deviation); non-normally distributed data were characterized using nonparametric descriptors (ie, median and quartiles). Statistical evaluation of improvement in pain status was performed by calculating 99% confidence intervals and using the Student t test for change between subsequent time points. Use of confidence intervals provides a descriptive analysis of the observed treatment effect, while permitting determination of statistical relevance. In all statistical testing, confidence bounds not including 0 were considered statistically significant. Probability of P ≤ .01 for committing type I experiment-wise error (rejecting a true null hypothesis) was selected for all statistical testing because of our lack of a control group, small sample size, and evaluation of multiple postoperative time points.

Results

Eighty consecutive patients with tendinosis of the elbow were included in this study. Sixty-nine patients were treated for lateral epicondylitis and 11 for medial epicondylitis. The average age of the patients (33 women, 47 men) was 50 years. The duration of follow-up evaluation ranged from 6 months to 9 years (mean, 2.5 years; median, 2 years). The Table presents the VAS improvement for these patients after the RF microtenotomy.

Within the lateral epicondylitis group, 91% (63/69) of the patients reported a successful outcome. The postoperative VAS improved to 1.3 from 6.9, which demonstrated an 81% improvement. Of the 6 patients that did not improve, 2 underwent repeat surgery.

Among the patients treated for medial epicondylitis, 91% (10/11) reported improvement in symptoms. The postoperative VAS improved to 1.3 from 6.1, a 79% improvement. One patient did not improve and did not undergo repeat surgery.

Discussion

For the treatment of medial and lateral elbow epicondylitis, RF microtenotomy is successful in 91% of patients. Symptomatic improvement was observed up to 9 years postoperatively. During this study, no complications were recorded; 7 treatment failures occurred. When compared with other techniques, the results with RF microtenotomy are equivalent or better.

In a retrospective study, Szabo and colleagues¹⁴ compared open, arthroscopic, and percutaneous release for lateral elbow tendinosis. They found the 3 methods to be highly effective for the treatment of tendinosis with no significant difference between them. Resection of the epicondyle and transfer of the anconeus muscle was found to be effective (94%) in a retrospective study by Almquist and colleagues.¹⁵ Dunn and coauthors¹⁶ reported a 97% success rate at 10 to 14 years postoperatively with a mini-open technique. Rubenthaler and colleagues¹⁷ showed 88% effectiveness for the open technique and 93% for the arthroscopic technique. With arthroscopic release of the extensor carpi radialis brevis tendon, Lattermann and coauthors¹⁸ reported clinical improvement in 94% of patients. In a study by Rose and colleagues,¹⁹ denervation of the lateral epicondyle was effective in relieving pain in 80% of patients who had had a positive response to a local anesthetic block. In a recently published study by Koh and coauthors,²⁰ 19 of 20 patients experienced a favorable outcome after treatment with ultrasonic microresection.

Regardless of surgical methods and their reported success rate, complications are associated with elbow surgery. Postoperative problems may include restricted function, elbow instability, persistent muscle weakness, and painful neuroma of the posterior cutaneous nerve.^10,21,22 The recent introduction of arthroscopic release offers the potential for less morbidity and enables visualization of the elbow joint. However, disadvantages of the arthroscopic approach include violation of the joint for extra-articular pathology, increased operative time and cost, and neurovascular complications. Additionally, it is possible that the entire spectrum of extra-articular tendinosis cannot be effectively identified arthroscopically.²³ In a prospective, randomized study, Meknas and colleagues²⁴ compared RF microtenotomy with extensor tendon release and repair. They showed that patients treated with RF-microtenotomy experienced earlier pain relief and improved grip strength over the release group.

Different proposed mechanisms of action have been described to explain the favorable effects of the RF-based microtenotomy procedure, such as induced healing by an angiogenic response in the tendon tissue. In an animal study, Harwood and colleagues⁸ showed that low-dose RF-based plasma microtenotomy has the ability to stimulate angiogenic growth factors in tendons, such as α_v integrin and vascular endothelial growth factor. These factors have been shown to be associated with healing.⁸ Early inflammatory response with new-vessel formation after 28 days was found in another animal study using the same method.²⁵ Evaluation of RF-based methods in a prospective controlled laboratory study using a rabbit-tendon model showed histologic evidence of early inflammation with development of neovasculature after treatment.⁸ A later histologic study using an aged Achilles rabbit tendon model was performed to evaluate the effect of RF-based plasma microtenotomy on collagen remodeling.²⁵ The degenerated tendon showed gaps, few normal crimpings, and a lack of reflectivity under polarized light. At 9 days after treatment, the treated tendon showed localized irregular crimpings, and, at 30 days, it showed regular crimping, tightly dense collagen fibers, and hypercellularity with good reflectivity. This was similar in appearance to a normal nondegenerated tendon (Figures 2A-2D). The RF-treated tendon also demonstrated an increase in production of insulin-like growth factor-1, β-fibroblast growth factor-1, α_v integrin, and vascular endothelial growth factor.

Pathologic nerve ingrowth or nerve irritation in the tendon substance has been considered a possible cause of the pain experienced with tendinosis. Radiofrequency treatment has been shown to induce acute degeneration and ablation of sensory nerve fibers.²⁶ These degenerated nerve fibers were observed to regenerate at 90 days after treatment.²⁷ These findings provide potential evidence for early pain relief that is maintained long term as the nerves regenerate.

This midterm follow-up of patients with elbow epicondylitis has shown that RF-based microtenotomy can produce successful, durable results. Microtenotomy is a technically simple procedure to perform and is associated with a rapid and uncomplicated recovery. It is safe and can effectively eliminate or markedly reduce clinical symptoms.

Limitations

Lateral epicondylitis has been described as a self-limited disease, with resolution of symptoms at 12 to 18 months with conservative treatment. This perspective challenges the indication of any proposed surgical treatment for the condition. Although the results of this research demonstrated the benefits of RF microtenotomy, there are inherent limitations of the study design. The study lacks a control group, and randomization would improve the strength of the study. Additional outcome measures, such as Disabilities of the Arm, Shoulder, and Hand score, and grip strength could complement pain scores to provide more data. These data were collected in a preliminary study.⁹ Postoperative histologic analysis of treated human tissue would be ideal, but ethical considerations limit study to animal models. An additional limitation is potential examiner bias. Data collection was performed by an independent medical technician; a third-party blinded evaluation could have been performed, but this was not feasible in a clinical setting.

Conclusion

Radiofrequency-based microtenotomy is a safe and effective procedure for elbow epicondylitis. The results are durable with successful outcomes observed 9 years after surgery.

Pigmented villonodular synovitis (PVNS) is a rare monoarticular disorder that affects the joints, bursae, or tendon sheaths of 1.8 per million patients.^1,2 PVNS is defined by exuberant proliferation of synovial villi and nodules. Although its etiology is unknown, PVNS behaves much as a neoplastic process does, with occasional chromosomal abnormalities, local tissue invasion, and the potential for malignant transformation.^3,4 Radiographs show cystic erosions or joint space narrowing, and magnetic resonance imaging shows characteristic low-signal intensity (on T1- and T2-weighted sequences) because of high hemosiderin content. Biopsy remains the gold standard for diagnosis and reveals hemosiderin-laden macrophages, vascularized villi, mononuclear cell infiltration, and sporadic mitotic figures.⁵ Diffuse PVNS appears as a thickened synovium with matted villi and synovial folds; localized PVNS presents as a pedunculated, firm yellow nodule.⁶

PVNS has a predilection for large joints, most commonly the knee (up to 80% of cases) and the hip.^1,2,7 Treatment strategies for knee PVNS have been well studied and, as an aggregate, show no superiority of arthroscopic or open techniques.⁸ The literature on hip PVNS is less abundant and more case-based, making it difficult to reach a consensus on effective treatment. Open synovectomy and arthroplasty have been the mainstays of treatment over the past 60 years, but the advent of hip arthroscopy has introduced a new treatment modality.^1,9 As arthroscopic management becomes more readily available, it is important to understand and compare the effectiveness of synovectomy and arthroplasty.

We systematically reviewed the treatment modalities for PVNS of the hip to determine how synovectomy and arthroplasty compare with respect to efficacy and revision rates.

Methods

Search Strategy

We systematically reviewed the literature according to PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines using the PRISMA checklist.¹⁰ Searches were completed in July 2014 using the PubMed Medline database and the Cochrane Central Register of Clinical Trials. Keyword selection was designed to capture all level I to V evidence English-language studies that reported clinical and/or radiographic outcomes. This was accomplished with a keyword search of all available titles and manuscript abstracts: (pigmented [Title/Abstract] AND villonodular [Title/Abstract] AND synovitis [Title/Abstract]) AND (hip [Title/Abstract]) AND (English [lang])). Abstracts from the 75 resulting studies were reviewed for exclusion criteria, which consisted of any cadaveric, biomechanical, histologic, and/or kinematic results, as well as a lack of any clinical and/or radiographic data (eg, review or technique articles). Studies were also excluded if they did not have clinical follow-up of at least 2 years. Studies not dedicated to hip PVNS specifically were not immediately excluded but were reviewed for outcomes data specific to the hip PVNS subpopulation. If a specific hip PVNS population could be distinguished from other patients, that study was included for review. If a study could not be deconstructed as such or was entirely devoted to one of our exclusion criteria, that study was excluded from our review. This initial search strategy yielded 16 studies.^1,6,7,11-28

Bibliographical review of these 16 studies yielded several more for review. To ensure that no patients were counted twice, each study’s authors, data collection period, and ethnic population were reviewed and compared with those of the other studies. If there was any overlap in authorship, period, and place, only the study with the most relevant or comprehensive data was included. After accounting for all inclusion and exclusion criteria, we selected a total of 21 studies with 82 patients (86 hips) for inclusion (Figure 1).

Data Extraction

Details of study design, sample size, and patient demographics, including age, sex, and duration of symptoms, were recorded. Use of diagnostic biopsy, joint space narrowing on radiographs, treatment method, and use of radiation therapy were also abstracted. Some studies described multiple treatment methods. If those methods could not be differentiated into distinct outcomes groups, the study would have been excluded for lack of specific clinical data. Studies with sufficient data were deconstructed such that the patients from each treatment group were isolated.

Fewer than 5 studies reported physical examination findings, validated survey scores, and/or radiographic results. Therefore, the primary outcomes reported and compared between treatment groups were disease recurrence, clinical worsening defined as progressive pain or loss of function, and revision surgery. Revision surgery was subdivided into repeat synovectomy and eventual arthroplasty, arthrodesis, or revision arthroplasty. Time to revision surgery was also documented. Each study’s methodologic quality and bias were evaluated with the Modified Coleman Methodology Score (MCMS), described by Cowan and colleagues.29 MCMS is a 15-item instrument that has been used to assess randomized and nonrandomized patient trials.^30,31 It has a scaled potential score ranging from 0 to 100, with scores from 85 through 100 indicating excellent, 70 through 84 good, 55 through 69 fair, and under 55 poor.

Statistical Analysis

We report our data as weighted means (SDs). A mean was calculated for each study reporting on a respective data point, and each mean was then weighted according to the sample size of that study. We multiplied each study’s individual mean by the number of patients enrolled in that study and divided the sum of all the studies’ weighted data points by the number of eligible patients in all relevant studies. The result is that the nonweighted means from studies with a smaller sample size did not carry as much weight as those from larger studies. We then compared 2 groups of patients: those who had only a synovectomy and those who had a combination of synovectomy and arthroplasty. The synovectomy-only group was also compared with a group that underwent total hip arthroplasty (THA) specifically (Figure 2). Groups were compared with Student t test (SPSS Version 18, IBM), and statistical significance was set at α = 0.05.

Results

Twenty-one studies (82 patients) were included in the final dataset (Table 1). Of these studies, 19 were retrospective case series (level IV evidence) in which the number of eligible hip PVNS patients ranged from 1 to 15. The other 2 studies were case reports (level V evidence). Mean (SD) MCMS was 25.0 (10.9).

Fifty-one patients (59.3%) were female. Mean (SD) age of all patients was 33.2 (12.6) years. Mean (SD) duration of symptoms was 4.2 (2.7) years. The right hip was affected in 59.5% of patients in whom laterality was documented. Sixty-eight patients (79.1%) had biopsy-proven PVNS; presence or absence of a biopsy was not documented for the other 18 patients.

Of the 82 patients in the study, 45 (54.9%) underwent synovectomy without arthroplasty. Staged radiation was used to augment the synovectomy in 2 of these 45 cases. One series in this group consisted of 15 cases of arthroscopic synovectomy.¹ The 37 patients (45.1%) in the other treatment group had arthroplasty at time of synovectomy. These patients underwent 22 THAs, 8 cup arthroplasties, 2 metal-on-metal hip resurfacings, and 1 hemiarthroplasty. The remaining 4 patients were treated nonoperatively (3) or with primary arthrodesis (1).

Comparisons between the synovectomy-only and synovectomy-with-arthroplasty groups are listed in Table 2. Synovectomy patients were younger on average than arthroplasty patients, but the difference was not statistically significant (P = .28). Only 6 studies distinguished between local and diffuse PVNS histology, and the diffuse type was detected in 87.0%, with insufficient data to detect a difference between the synovectomy and arthroplasty groups. In studies with documented radiographic findings, 75.0% of patients had evidence of joint space narrowing, which was significantly (P = .03) more common in the arthroplasty group (96.7% vs 31.3%).

Mean (SD) clinical follow-up was 8.4 (5.9) years for all patients. A larger percentage of synovectomy-only patients experienced recurrence and worsened symptoms, but neither trend achieved statistical significance. The rate of eventual THA or arthrodesis after synovectomy alone was almost identical (P = .17) to the rate of revision THA in the synovectomy-with-arthroplasty group (26.2% vs 24.3%). Time to revision surgery, however, was significantly (P = .02) longer in the arthroplasty group. Two additional patients in the synovectomy-with-arthroplasty group underwent repeat synovectomy alone, but no patients in the synovectomy-only group underwent repeat synovectomy without arthroplasty.

One nonoperatively managed patient experienced symptom progression over the course of 10 years. The other 2 patients were stable after 2- and 4-year follow-up. The arthrodesis patient did not experience recurrence or have a revision operation in the 5 years after the index procedure.

Discussion

PVNS is a proliferative disorder of synovial tissue with a high risk of recurrence.^15,32 Metastasis is extremely rare; there is only 1 case report of a fatality, which occurred within 42 months.¹² Chiari and colleagues¹⁵ suggested that the PVNS recurrence rate is highest in the large joints. Therefore, in hip PVNS, early surgical resection is needed to limit articular destruction and the potential for recurrence. The primary treatment modalities are synovectomy alone and synovectomy with arthroplasty, which includes THA, cup arthroplasty, hip resurfacing, and hemiarthroplasty. According to our systematic review, about one-fourth of all patients in both treatment groups ultimately underwent revision surgery. Mean time to revision was significantly longer for synovectomy-with-arthroplasty patients (almost 12 years) than for synovectomy-only patients (6.5 years). One potential explanation is that arthroplasty component fixation may take longer to loosen than an inadequately synovectomized joint takes to recur. The synovectomy-only group did have a higher recurrence rate, though the difference was not statistically significant.

Open synovectomy is the most widely described technique for addressing hip PVNS. The precise pathophysiology of PVNS remains largely unknown, but most authors agree that aggressive débridement is required to halt its locally invasive course. Scott²⁴ described the invasion of vascular foramina from synovium into bone and thought that radical synovectomy was essential to remove the stalks of these synovial villi. Furthermore, PVNS most commonly affects adults in the third through fifth decades of life,7 and many surgeons want to avoid prosthetic components (which may loosen over time) in this age group. Synovectomy, however, has persistently high recurrence rates, and, without removal of the femoral head and neck, it can be difficult to obtain adequate exposure for complete débridement. Although adjuvant external beam radiation has been used by some authors,^17,19,33 its utility is unproven, and other authors have cautioned against unnecessary irradiation of reproductive organs.^1,24,34

The high rates of bony involvement, joint destruction, and recurrence after synovectomy have prompted many surgeons to turn to arthroplasty. González Della Valle and colleagues18 theorized that joint space narrowing is more common in hip PVNS because of the poor distensibility of the hip capsule compared with that of the knee and other joints. In turn, bony lesions and arthritis present earlier in hip PVNS.¹⁴ Yoo and colleagues¹⁴ found a statistically significant increase in Harris Hip Scale (HHS) scores and a high rate of return to athletic activity after THA for PVNS. However, they also reported revisions for component loosening and osteolysis in 2 of 8 patients and periprosthetic osteolysis without loosening in another 2 patients. Vastel and colleagues¹⁶ similarly reported aseptic loosening of the acetabular component in half their patient cohort. No studies have determined which condition—PVNS recurrence or debris-related osteolysis—causes the accelerated loosening in this demographic.

Byrd and colleagues¹ recently described use of hip arthroscopy in the treatment of PVNS. In a cohort of 13 patients, they found statistically significant improvements in HHS scores, no postoperative complications, and only 1 revision (THA 6 years after surgery). Although there is a prevailing perception that nodular (vs diffuse) PVNS is more appropriately treated with arthroscopic excision, no studies have provided data on this effect, and Byrd and colleagues¹ in fact showed a trend of slightly better outcomes in diffuse cases than in nodular cases. The main challenges of hip arthroscopy are the steep learning curve and adequate exposure. Recent innovations include additional arthroscopic portals and enlarged T-capsulotomy, which may be contributing to decreased complication rates in hip arthroscopy in general.³⁵

The limitations of this systematic review were largely imposed by the studies analyzed. The primary limitation was the relative paucity of clinical and radiographic data on hip PVNS. To our knowledge, studies on the treatment of hip PVNS have reported evidence levels no higher than IV. In addition, the studies we reviewed often had only 1 or 2 patient cases satisfying our inclusion criteria. For this reason, we included case reports, which further lowered the level of evidence of studies used. There were no consistently reported physical examination, survey, or radiographic findings that could be used to compare studies. All studies with sufficient data on hip PVNS treatment outcomes were rated poorly with the Modified Coleman Methodology Scoring system.²⁹ Selection bias was minimized by the inclusive nature of studies with level I to V evidence, but this led to a study design bias in that most studies consisted of level IV evidence.

Conclusion

Although the hip PVNS literature is limited, our review provides insight into expected outcomes. No matter which surgery is to be performed, surgeons must counsel patients about the high revision rate. One in 4 patients ultimately undergoes a second surgery, which may be required within 6 or 7 years after synovectomy without arthroplasty. Further development and innovation in hip arthroscopy may transform the treatment of PVNS. We encourage other investigators to conduct prospective, comparative trials with higher evidence levels to assess the utility of arthroscopy and other treatment modalities.

Pigmented villonodular synovitis (PVNS) is a rare monoarticular disorder that affects the joints, bursae, or tendon sheaths of 1.8 per million patients.^1,2 PVNS is defined by exuberant proliferation of synovial villi and nodules. Although its etiology is unknown, PVNS behaves much as a neoplastic process does, with occasional chromosomal abnormalities, local tissue invasion, and the potential for malignant transformation.^3,4 Radiographs show cystic erosions or joint space narrowing, and magnetic resonance imaging shows characteristic low-signal intensity (on T1- and T2-weighted sequences) because of high hemosiderin content. Biopsy remains the gold standard for diagnosis and reveals hemosiderin-laden macrophages, vascularized villi, mononuclear cell infiltration, and sporadic mitotic figures.⁵ Diffuse PVNS appears as a thickened synovium with matted villi and synovial folds; localized PVNS presents as a pedunculated, firm yellow nodule.⁶

PVNS has a predilection for large joints, most commonly the knee (up to 80% of cases) and the hip.^1,2,7 Treatment strategies for knee PVNS have been well studied and, as an aggregate, show no superiority of arthroscopic or open techniques.⁸ The literature on hip PVNS is less abundant and more case-based, making it difficult to reach a consensus on effective treatment. Open synovectomy and arthroplasty have been the mainstays of treatment over the past 60 years, but the advent of hip arthroscopy has introduced a new treatment modality.^1,9 As arthroscopic management becomes more readily available, it is important to understand and compare the effectiveness of synovectomy and arthroplasty.

We systematically reviewed the treatment modalities for PVNS of the hip to determine how synovectomy and arthroplasty compare with respect to efficacy and revision rates.

Methods

Search Strategy

We systematically reviewed the literature according to PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines using the PRISMA checklist.¹⁰ Searches were completed in July 2014 using the PubMed Medline database and the Cochrane Central Register of Clinical Trials. Keyword selection was designed to capture all level I to V evidence English-language studies that reported clinical and/or radiographic outcomes. This was accomplished with a keyword search of all available titles and manuscript abstracts: (pigmented [Title/Abstract] AND villonodular [Title/Abstract] AND synovitis [Title/Abstract]) AND (hip [Title/Abstract]) AND (English [lang])). Abstracts from the 75 resulting studies were reviewed for exclusion criteria, which consisted of any cadaveric, biomechanical, histologic, and/or kinematic results, as well as a lack of any clinical and/or radiographic data (eg, review or technique articles). Studies were also excluded if they did not have clinical follow-up of at least 2 years. Studies not dedicated to hip PVNS specifically were not immediately excluded but were reviewed for outcomes data specific to the hip PVNS subpopulation. If a specific hip PVNS population could be distinguished from other patients, that study was included for review. If a study could not be deconstructed as such or was entirely devoted to one of our exclusion criteria, that study was excluded from our review. This initial search strategy yielded 16 studies.^1,6,7,11-28

Bibliographical review of these 16 studies yielded several more for review. To ensure that no patients were counted twice, each study’s authors, data collection period, and ethnic population were reviewed and compared with those of the other studies. If there was any overlap in authorship, period, and place, only the study with the most relevant or comprehensive data was included. After accounting for all inclusion and exclusion criteria, we selected a total of 21 studies with 82 patients (86 hips) for inclusion (Figure 1).

Data Extraction

Details of study design, sample size, and patient demographics, including age, sex, and duration of symptoms, were recorded. Use of diagnostic biopsy, joint space narrowing on radiographs, treatment method, and use of radiation therapy were also abstracted. Some studies described multiple treatment methods. If those methods could not be differentiated into distinct outcomes groups, the study would have been excluded for lack of specific clinical data. Studies with sufficient data were deconstructed such that the patients from each treatment group were isolated.

Fewer than 5 studies reported physical examination findings, validated survey scores, and/or radiographic results. Therefore, the primary outcomes reported and compared between treatment groups were disease recurrence, clinical worsening defined as progressive pain or loss of function, and revision surgery. Revision surgery was subdivided into repeat synovectomy and eventual arthroplasty, arthrodesis, or revision arthroplasty. Time to revision surgery was also documented. Each study’s methodologic quality and bias were evaluated with the Modified Coleman Methodology Score (MCMS), described by Cowan and colleagues.29 MCMS is a 15-item instrument that has been used to assess randomized and nonrandomized patient trials.^30,31 It has a scaled potential score ranging from 0 to 100, with scores from 85 through 100 indicating excellent, 70 through 84 good, 55 through 69 fair, and under 55 poor.

Statistical Analysis

We report our data as weighted means (SDs). A mean was calculated for each study reporting on a respective data point, and each mean was then weighted according to the sample size of that study. We multiplied each study’s individual mean by the number of patients enrolled in that study and divided the sum of all the studies’ weighted data points by the number of eligible patients in all relevant studies. The result is that the nonweighted means from studies with a smaller sample size did not carry as much weight as those from larger studies. We then compared 2 groups of patients: those who had only a synovectomy and those who had a combination of synovectomy and arthroplasty. The synovectomy-only group was also compared with a group that underwent total hip arthroplasty (THA) specifically (Figure 2). Groups were compared with Student t test (SPSS Version 18, IBM), and statistical significance was set at α = 0.05.

Results

Twenty-one studies (82 patients) were included in the final dataset (Table 1). Of these studies, 19 were retrospective case series (level IV evidence) in which the number of eligible hip PVNS patients ranged from 1 to 15. The other 2 studies were case reports (level V evidence). Mean (SD) MCMS was 25.0 (10.9).

Fifty-one patients (59.3%) were female. Mean (SD) age of all patients was 33.2 (12.6) years. Mean (SD) duration of symptoms was 4.2 (2.7) years. The right hip was affected in 59.5% of patients in whom laterality was documented. Sixty-eight patients (79.1%) had biopsy-proven PVNS; presence or absence of a biopsy was not documented for the other 18 patients.

Of the 82 patients in the study, 45 (54.9%) underwent synovectomy without arthroplasty. Staged radiation was used to augment the synovectomy in 2 of these 45 cases. One series in this group consisted of 15 cases of arthroscopic synovectomy.¹ The 37 patients (45.1%) in the other treatment group had arthroplasty at time of synovectomy. These patients underwent 22 THAs, 8 cup arthroplasties, 2 metal-on-metal hip resurfacings, and 1 hemiarthroplasty. The remaining 4 patients were treated nonoperatively (3) or with primary arthrodesis (1).

Comparisons between the synovectomy-only and synovectomy-with-arthroplasty groups are listed in Table 2. Synovectomy patients were younger on average than arthroplasty patients, but the difference was not statistically significant (P = .28). Only 6 studies distinguished between local and diffuse PVNS histology, and the diffuse type was detected in 87.0%, with insufficient data to detect a difference between the synovectomy and arthroplasty groups. In studies with documented radiographic findings, 75.0% of patients had evidence of joint space narrowing, which was significantly (P = .03) more common in the arthroplasty group (96.7% vs 31.3%).

Mean (SD) clinical follow-up was 8.4 (5.9) years for all patients. A larger percentage of synovectomy-only patients experienced recurrence and worsened symptoms, but neither trend achieved statistical significance. The rate of eventual THA or arthrodesis after synovectomy alone was almost identical (P = .17) to the rate of revision THA in the synovectomy-with-arthroplasty group (26.2% vs 24.3%). Time to revision surgery, however, was significantly (P = .02) longer in the arthroplasty group. Two additional patients in the synovectomy-with-arthroplasty group underwent repeat synovectomy alone, but no patients in the synovectomy-only group underwent repeat synovectomy without arthroplasty.

One nonoperatively managed patient experienced symptom progression over the course of 10 years. The other 2 patients were stable after 2- and 4-year follow-up. The arthrodesis patient did not experience recurrence or have a revision operation in the 5 years after the index procedure.

Discussion

PVNS is a proliferative disorder of synovial tissue with a high risk of recurrence.^15,32 Metastasis is extremely rare; there is only 1 case report of a fatality, which occurred within 42 months.¹² Chiari and colleagues¹⁵ suggested that the PVNS recurrence rate is highest in the large joints. Therefore, in hip PVNS, early surgical resection is needed to limit articular destruction and the potential for recurrence. The primary treatment modalities are synovectomy alone and synovectomy with arthroplasty, which includes THA, cup arthroplasty, hip resurfacing, and hemiarthroplasty. According to our systematic review, about one-fourth of all patients in both treatment groups ultimately underwent revision surgery. Mean time to revision was significantly longer for synovectomy-with-arthroplasty patients (almost 12 years) than for synovectomy-only patients (6.5 years). One potential explanation is that arthroplasty component fixation may take longer to loosen than an inadequately synovectomized joint takes to recur. The synovectomy-only group did have a higher recurrence rate, though the difference was not statistically significant.

Open synovectomy is the most widely described technique for addressing hip PVNS. The precise pathophysiology of PVNS remains largely unknown, but most authors agree that aggressive débridement is required to halt its locally invasive course. Scott²⁴ described the invasion of vascular foramina from synovium into bone and thought that radical synovectomy was essential to remove the stalks of these synovial villi. Furthermore, PVNS most commonly affects adults in the third through fifth decades of life,7 and many surgeons want to avoid prosthetic components (which may loosen over time) in this age group. Synovectomy, however, has persistently high recurrence rates, and, without removal of the femoral head and neck, it can be difficult to obtain adequate exposure for complete débridement. Although adjuvant external beam radiation has been used by some authors,^17,19,33 its utility is unproven, and other authors have cautioned against unnecessary irradiation of reproductive organs.^1,24,34

The high rates of bony involvement, joint destruction, and recurrence after synovectomy have prompted many surgeons to turn to arthroplasty. González Della Valle and colleagues18 theorized that joint space narrowing is more common in hip PVNS because of the poor distensibility of the hip capsule compared with that of the knee and other joints. In turn, bony lesions and arthritis present earlier in hip PVNS.¹⁴ Yoo and colleagues¹⁴ found a statistically significant increase in Harris Hip Scale (HHS) scores and a high rate of return to athletic activity after THA for PVNS. However, they also reported revisions for component loosening and osteolysis in 2 of 8 patients and periprosthetic osteolysis without loosening in another 2 patients. Vastel and colleagues¹⁶ similarly reported aseptic loosening of the acetabular component in half their patient cohort. No studies have determined which condition—PVNS recurrence or debris-related osteolysis—causes the accelerated loosening in this demographic.

Byrd and colleagues¹ recently described use of hip arthroscopy in the treatment of PVNS. In a cohort of 13 patients, they found statistically significant improvements in HHS scores, no postoperative complications, and only 1 revision (THA 6 years after surgery). Although there is a prevailing perception that nodular (vs diffuse) PVNS is more appropriately treated with arthroscopic excision, no studies have provided data on this effect, and Byrd and colleagues¹ in fact showed a trend of slightly better outcomes in diffuse cases than in nodular cases. The main challenges of hip arthroscopy are the steep learning curve and adequate exposure. Recent innovations include additional arthroscopic portals and enlarged T-capsulotomy, which may be contributing to decreased complication rates in hip arthroscopy in general.³⁵

The limitations of this systematic review were largely imposed by the studies analyzed. The primary limitation was the relative paucity of clinical and radiographic data on hip PVNS. To our knowledge, studies on the treatment of hip PVNS have reported evidence levels no higher than IV. In addition, the studies we reviewed often had only 1 or 2 patient cases satisfying our inclusion criteria. For this reason, we included case reports, which further lowered the level of evidence of studies used. There were no consistently reported physical examination, survey, or radiographic findings that could be used to compare studies. All studies with sufficient data on hip PVNS treatment outcomes were rated poorly with the Modified Coleman Methodology Scoring system.²⁹ Selection bias was minimized by the inclusive nature of studies with level I to V evidence, but this led to a study design bias in that most studies consisted of level IV evidence.

Conclusion

Although the hip PVNS literature is limited, our review provides insight into expected outcomes. No matter which surgery is to be performed, surgeons must counsel patients about the high revision rate. One in 4 patients ultimately undergoes a second surgery, which may be required within 6 or 7 years after synovectomy without arthroplasty. Further development and innovation in hip arthroscopy may transform the treatment of PVNS. We encourage other investigators to conduct prospective, comparative trials with higher evidence levels to assess the utility of arthroscopy and other treatment modalities.

Pigmented villonodular synovitis (PVNS) is a rare monoarticular disorder that affects the joints, bursae, or tendon sheaths of 1.8 per million patients.^1,2 PVNS is defined by exuberant proliferation of synovial villi and nodules. Although its etiology is unknown, PVNS behaves much as a neoplastic process does, with occasional chromosomal abnormalities, local tissue invasion, and the potential for malignant transformation.^3,4 Radiographs show cystic erosions or joint space narrowing, and magnetic resonance imaging shows characteristic low-signal intensity (on T1- and T2-weighted sequences) because of high hemosiderin content. Biopsy remains the gold standard for diagnosis and reveals hemosiderin-laden macrophages, vascularized villi, mononuclear cell infiltration, and sporadic mitotic figures.⁵ Diffuse PVNS appears as a thickened synovium with matted villi and synovial folds; localized PVNS presents as a pedunculated, firm yellow nodule.⁶

PVNS has a predilection for large joints, most commonly the knee (up to 80% of cases) and the hip.^1,2,7 Treatment strategies for knee PVNS have been well studied and, as an aggregate, show no superiority of arthroscopic or open techniques.⁸ The literature on hip PVNS is less abundant and more case-based, making it difficult to reach a consensus on effective treatment. Open synovectomy and arthroplasty have been the mainstays of treatment over the past 60 years, but the advent of hip arthroscopy has introduced a new treatment modality.^1,9 As arthroscopic management becomes more readily available, it is important to understand and compare the effectiveness of synovectomy and arthroplasty.

We systematically reviewed the treatment modalities for PVNS of the hip to determine how synovectomy and arthroplasty compare with respect to efficacy and revision rates.

Methods

Search Strategy

We systematically reviewed the literature according to PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines using the PRISMA checklist.¹⁰ Searches were completed in July 2014 using the PubMed Medline database and the Cochrane Central Register of Clinical Trials. Keyword selection was designed to capture all level I to V evidence English-language studies that reported clinical and/or radiographic outcomes. This was accomplished with a keyword search of all available titles and manuscript abstracts: (pigmented [Title/Abstract] AND villonodular [Title/Abstract] AND synovitis [Title/Abstract]) AND (hip [Title/Abstract]) AND (English [lang])). Abstracts from the 75 resulting studies were reviewed for exclusion criteria, which consisted of any cadaveric, biomechanical, histologic, and/or kinematic results, as well as a lack of any clinical and/or radiographic data (eg, review or technique articles). Studies were also excluded if they did not have clinical follow-up of at least 2 years. Studies not dedicated to hip PVNS specifically were not immediately excluded but were reviewed for outcomes data specific to the hip PVNS subpopulation. If a specific hip PVNS population could be distinguished from other patients, that study was included for review. If a study could not be deconstructed as such or was entirely devoted to one of our exclusion criteria, that study was excluded from our review. This initial search strategy yielded 16 studies.^1,6,7,11-28

Bibliographical review of these 16 studies yielded several more for review. To ensure that no patients were counted twice, each study’s authors, data collection period, and ethnic population were reviewed and compared with those of the other studies. If there was any overlap in authorship, period, and place, only the study with the most relevant or comprehensive data was included. After accounting for all inclusion and exclusion criteria, we selected a total of 21 studies with 82 patients (86 hips) for inclusion (Figure 1).

Data Extraction

Details of study design, sample size, and patient demographics, including age, sex, and duration of symptoms, were recorded. Use of diagnostic biopsy, joint space narrowing on radiographs, treatment method, and use of radiation therapy were also abstracted. Some studies described multiple treatment methods. If those methods could not be differentiated into distinct outcomes groups, the study would have been excluded for lack of specific clinical data. Studies with sufficient data were deconstructed such that the patients from each treatment group were isolated.

Fewer than 5 studies reported physical examination findings, validated survey scores, and/or radiographic results. Therefore, the primary outcomes reported and compared between treatment groups were disease recurrence, clinical worsening defined as progressive pain or loss of function, and revision surgery. Revision surgery was subdivided into repeat synovectomy and eventual arthroplasty, arthrodesis, or revision arthroplasty. Time to revision surgery was also documented. Each study’s methodologic quality and bias were evaluated with the Modified Coleman Methodology Score (MCMS), described by Cowan and colleagues.29 MCMS is a 15-item instrument that has been used to assess randomized and nonrandomized patient trials.^30,31 It has a scaled potential score ranging from 0 to 100, with scores from 85 through 100 indicating excellent, 70 through 84 good, 55 through 69 fair, and under 55 poor.

Statistical Analysis

We report our data as weighted means (SDs). A mean was calculated for each study reporting on a respective data point, and each mean was then weighted according to the sample size of that study. We multiplied each study’s individual mean by the number of patients enrolled in that study and divided the sum of all the studies’ weighted data points by the number of eligible patients in all relevant studies. The result is that the nonweighted means from studies with a smaller sample size did not carry as much weight as those from larger studies. We then compared 2 groups of patients: those who had only a synovectomy and those who had a combination of synovectomy and arthroplasty. The synovectomy-only group was also compared with a group that underwent total hip arthroplasty (THA) specifically (Figure 2). Groups were compared with Student t test (SPSS Version 18, IBM), and statistical significance was set at α = 0.05.

Results

Twenty-one studies (82 patients) were included in the final dataset (Table 1). Of these studies, 19 were retrospective case series (level IV evidence) in which the number of eligible hip PVNS patients ranged from 1 to 15. The other 2 studies were case reports (level V evidence). Mean (SD) MCMS was 25.0 (10.9).

Fifty-one patients (59.3%) were female. Mean (SD) age of all patients was 33.2 (12.6) years. Mean (SD) duration of symptoms was 4.2 (2.7) years. The right hip was affected in 59.5% of patients in whom laterality was documented. Sixty-eight patients (79.1%) had biopsy-proven PVNS; presence or absence of a biopsy was not documented for the other 18 patients.

Of the 82 patients in the study, 45 (54.9%) underwent synovectomy without arthroplasty. Staged radiation was used to augment the synovectomy in 2 of these 45 cases. One series in this group consisted of 15 cases of arthroscopic synovectomy.¹ The 37 patients (45.1%) in the other treatment group had arthroplasty at time of synovectomy. These patients underwent 22 THAs, 8 cup arthroplasties, 2 metal-on-metal hip resurfacings, and 1 hemiarthroplasty. The remaining 4 patients were treated nonoperatively (3) or with primary arthrodesis (1).

Comparisons between the synovectomy-only and synovectomy-with-arthroplasty groups are listed in Table 2. Synovectomy patients were younger on average than arthroplasty patients, but the difference was not statistically significant (P = .28). Only 6 studies distinguished between local and diffuse PVNS histology, and the diffuse type was detected in 87.0%, with insufficient data to detect a difference between the synovectomy and arthroplasty groups. In studies with documented radiographic findings, 75.0% of patients had evidence of joint space narrowing, which was significantly (P = .03) more common in the arthroplasty group (96.7% vs 31.3%).

Mean (SD) clinical follow-up was 8.4 (5.9) years for all patients. A larger percentage of synovectomy-only patients experienced recurrence and worsened symptoms, but neither trend achieved statistical significance. The rate of eventual THA or arthrodesis after synovectomy alone was almost identical (P = .17) to the rate of revision THA in the synovectomy-with-arthroplasty group (26.2% vs 24.3%). Time to revision surgery, however, was significantly (P = .02) longer in the arthroplasty group. Two additional patients in the synovectomy-with-arthroplasty group underwent repeat synovectomy alone, but no patients in the synovectomy-only group underwent repeat synovectomy without arthroplasty.

One nonoperatively managed patient experienced symptom progression over the course of 10 years. The other 2 patients were stable after 2- and 4-year follow-up. The arthrodesis patient did not experience recurrence or have a revision operation in the 5 years after the index procedure.

Discussion

PVNS is a proliferative disorder of synovial tissue with a high risk of recurrence.^15,32 Metastasis is extremely rare; there is only 1 case report of a fatality, which occurred within 42 months.¹² Chiari and colleagues¹⁵ suggested that the PVNS recurrence rate is highest in the large joints. Therefore, in hip PVNS, early surgical resection is needed to limit articular destruction and the potential for recurrence. The primary treatment modalities are synovectomy alone and synovectomy with arthroplasty, which includes THA, cup arthroplasty, hip resurfacing, and hemiarthroplasty. According to our systematic review, about one-fourth of all patients in both treatment groups ultimately underwent revision surgery. Mean time to revision was significantly longer for synovectomy-with-arthroplasty patients (almost 12 years) than for synovectomy-only patients (6.5 years). One potential explanation is that arthroplasty component fixation may take longer to loosen than an inadequately synovectomized joint takes to recur. The synovectomy-only group did have a higher recurrence rate, though the difference was not statistically significant.

Open synovectomy is the most widely described technique for addressing hip PVNS. The precise pathophysiology of PVNS remains largely unknown, but most authors agree that aggressive débridement is required to halt its locally invasive course. Scott²⁴ described the invasion of vascular foramina from synovium into bone and thought that radical synovectomy was essential to remove the stalks of these synovial villi. Furthermore, PVNS most commonly affects adults in the third through fifth decades of life,7 and many surgeons want to avoid prosthetic components (which may loosen over time) in this age group. Synovectomy, however, has persistently high recurrence rates, and, without removal of the femoral head and neck, it can be difficult to obtain adequate exposure for complete débridement. Although adjuvant external beam radiation has been used by some authors,^17,19,33 its utility is unproven, and other authors have cautioned against unnecessary irradiation of reproductive organs.^1,24,34

The high rates of bony involvement, joint destruction, and recurrence after synovectomy have prompted many surgeons to turn to arthroplasty. González Della Valle and colleagues18 theorized that joint space narrowing is more common in hip PVNS because of the poor distensibility of the hip capsule compared with that of the knee and other joints. In turn, bony lesions and arthritis present earlier in hip PVNS.¹⁴ Yoo and colleagues¹⁴ found a statistically significant increase in Harris Hip Scale (HHS) scores and a high rate of return to athletic activity after THA for PVNS. However, they also reported revisions for component loosening and osteolysis in 2 of 8 patients and periprosthetic osteolysis without loosening in another 2 patients. Vastel and colleagues¹⁶ similarly reported aseptic loosening of the acetabular component in half their patient cohort. No studies have determined which condition—PVNS recurrence or debris-related osteolysis—causes the accelerated loosening in this demographic.

Byrd and colleagues¹ recently described use of hip arthroscopy in the treatment of PVNS. In a cohort of 13 patients, they found statistically significant improvements in HHS scores, no postoperative complications, and only 1 revision (THA 6 years after surgery). Although there is a prevailing perception that nodular (vs diffuse) PVNS is more appropriately treated with arthroscopic excision, no studies have provided data on this effect, and Byrd and colleagues¹ in fact showed a trend of slightly better outcomes in diffuse cases than in nodular cases. The main challenges of hip arthroscopy are the steep learning curve and adequate exposure. Recent innovations include additional arthroscopic portals and enlarged T-capsulotomy, which may be contributing to decreased complication rates in hip arthroscopy in general.³⁵

The limitations of this systematic review were largely imposed by the studies analyzed. The primary limitation was the relative paucity of clinical and radiographic data on hip PVNS. To our knowledge, studies on the treatment of hip PVNS have reported evidence levels no higher than IV. In addition, the studies we reviewed often had only 1 or 2 patient cases satisfying our inclusion criteria. For this reason, we included case reports, which further lowered the level of evidence of studies used. There were no consistently reported physical examination, survey, or radiographic findings that could be used to compare studies. All studies with sufficient data on hip PVNS treatment outcomes were rated poorly with the Modified Coleman Methodology Scoring system.²⁹ Selection bias was minimized by the inclusive nature of studies with level I to V evidence, but this led to a study design bias in that most studies consisted of level IV evidence.

Conclusion

Although the hip PVNS literature is limited, our review provides insight into expected outcomes. No matter which surgery is to be performed, surgeons must counsel patients about the high revision rate. One in 4 patients ultimately undergoes a second surgery, which may be required within 6 or 7 years after synovectomy without arthroplasty. Further development and innovation in hip arthroscopy may transform the treatment of PVNS. We encourage other investigators to conduct prospective, comparative trials with higher evidence levels to assess the utility of arthroscopy and other treatment modalities.

 Compartment syndrome (CS) is one of the true orthopedic emergencies. Identifying the high-risk patient, making a prompt diagnosis, and initiating effective treatment are the crucial steps in avoiding a poor outcome. A physician’s inability to communicate with young children can interfere with diagnosing CS in a timely fashion. Many young patients in hospitals are admitted to pediatric floors where routine orthopedic care is not the norm and staff are unfamiliar with the signs and symptoms of evolving CS. As orthopedic surgeons are often involved in caring for these patients, they should be aware of the aspects of CS that are unique to children and should be able to identify patients who are at risk and would benefit from close monitoring. In addition, given the consequences of late diagnosis, early diagnosis is important from a medicolegal standpoint. Only 44% of cases of adult and pediatric CS are decided in favor of treating physicians, compared with 75% of cases in other orthopedic malpractice claims.1,2

Risk Factors for Posttraumatic Compartment Syndrome

Supracondylar Humeral Fracture

CS is a well-described complication of this injury. CS develops in 0.1% to 0.3% of children who present with supracondylar humeral fracture.^3,4 Casted elbow flexion beyond 90° and concomitant vascular injury put these children at increased risk for CS. Mubarak and Carroll⁵ reported 9 cases of CS in the volar compartment of the forearm after an extension-type supracondylar humeral fracture and attributed 8 of them to elbow flexion beyond 90° after closed reduction. In 29 children with supracondylar humeral fracture,Battaglia and colleagues³ found the highest compartment pressure in the deep volar compartment, especially near the fracture site, as well as a significant increase in pressure with the elbow flexed beyond 90°.

In a study of children with supracondylar humeral fracture, Choi and colleagues⁶ found 2 cases of CS among 9 patients who presented with a pulseless, poorly perfused hand and no cases of CS among 24 patients who presented with a pulseless but well-perfused hand.

Studies have found that a treatment delay of 8 to 12 hours did not increase the rate of CS in Gartland type 2 and type 3 fractures.^7-10 The investigators in these studies did not recommend delaying treatment of patients with neurologic deficit and absent radial pulse. Ramachandran and colleagues4 reported 11 cases of CS in patients with low-energy supracondylar humeral fracture and intact radial pulse at presentation. The patients who developed CS presented with severe swelling, and their mean treatment delay was 22 hours (range, 6-64 hours). Given the data, we do not recommend delayed treatment for children with supracondylar humeral fracture and neurologic deficit or absent pulse. We do recommend close inpatient preoperative monitoring of patients with severe swelling.

CS after supracondylar humeral fracture is mostly seen in the volar compartment of the forearm, but it has also been reported in the mobile wad, the anterior arm compartment, and the posterior arm compartment.^11,12

Floating Elbow

CS has been reported in children with ipsilateral humeral and forearm fractures. Blakemore and colleagues¹³ reported a 33% rate of CS in children with displaced distal humeral and forearm fractures. A retrospective review of 16 cases of floating elbow treated at Boston Children’s Hospital found CS in 2 patients and incipient CS in 4 of 10 patients with forearm fractures treated with closed reduction and plaster casting. There were no signs of CS in 6 patients with distal humeral and forearm fractures stabilized with Kirschner wires.¹⁴ Given the data, we do not recommend circumferential casting for forearm fractures in children with floating elbow.

Forearm Fracture

Haasbeek and Cole¹⁵ reported CS in 5 (11%) of 46 children with open forearm fracture. Yuan and colleagues¹⁶ reported CS in 3 (6%) of 50 open forearm fractures and 3 of 30 closed fractures treated with closed reduction and intramedullary nailing. They found increased risk for CS in patients with longer operative time, indicating prolonged closed manipulation of these fractures as a risk factor for CS. They did not find any cases of CS among 205 forearm fractures treated with closed reduction and casting.

Flynn and colleagues17 reported CS in 2 of 30 patients treated with intramedullary nailing within 24 hours of injury and in 0 of 73 patients treated after 24 hours.

Blackman and colleagues¹⁸ reported CS in 3 (7.7%) of 39 open forearm fractures and 0 of 74 closed fractures treated operatively. In their series, a small incision was made to facilitate reduction in 38 (51.4%) of 74 closed fractures to decrease closed manipulation and operative time. The rate of CS after intramedullary nailing of closed forearm fractures was lower in this series than in similar reports in the literature.

Reported data indicate increased risk for CS in children with open forearm fractures and fractures treated with closed reduction and intramedullary nailing, especially performed within 24 hours of injury, and prolonged closed manipulation performed during surgery. We recommend close monitoring of all children with operatively treated forearm fractures and, in particular, children with the risk factors mentioned.

Femoral Fracture

Although CS after femoral shaft fractures is not common, CS has been reported after 90/90 spica casting of femoral shaft fractures in children. Mubarak and colleagues19 reported on 9 children who developed calf CS after treatment of femoral shaft fracture in 90/90 spica casts. The technique used in 7 of the 9 reported cases involved initial application of a short leg cast and then traction applied to the leg—believed to cause impinging of the cast on the posterior compartment of the leg. The authors recommended an alternative method of applying spica casts, which is beyond the scope of this review.

Tibial Fracture

Children with tibial fracture, especially a fracture sustained in a motor vehicle accident, are at risk for CS. Hope and Cole²⁰ found CS in 4 (4%) of 92 children with open tibial fracture.

Children with tibial tubercle fracture are at increased risk for CS because of concomitant vascular injury. Pandya and colleagues²¹ reported CS or vascular compromise in 4 of 40 patients with tibial tubercle fracture. We recommend close monitoring for signs of impending CS in children who present with high-energy tibial shaft fracture and tibial tubercle fracture.

Flynn and colleagues²² reported outcomes of 43 cases of acute CS of the leg in children treated at 2 pediatric trauma centers. Mean time from injury to fasciotomy was 20.5 hours (range, 3.9-118 hours). Functional outcome was excellent at time of follow-up; 41 of 43 cases had no sequelae, and the 2 patients who lost function underwent fasciotomy more than 80 hours after injury. Despite the long interval between injury and surgery, excellent results were achieved with fasciotomy, suggesting an increased potential for recovery in the pediatric population.

Mubarak²³ reported on 6 cases of distal tibial physis fracture in patients who presented with severe pain and swelling of the ankle, hyposthesia of the first web space, weakness of the extensor hallucis longus and extensor digitorum communis, and pain on passive flexion of the toes. In all these patients, intramuscular pressure was more than 40 mm Hg beneath the extensor retinaculum and less than 20 mm Hg in the anterior compartment. All patients experienced prompt relief of pain and improved sensation and strength within 24 hours after release of the superior extensor retinaculum and fracture stabilization.

Miscellaneous and Nontraumatic Causes of Compartment Syndrome

Neonatal CS is very rare, and diagnosis is often missed. Neonatal CS is thought to be caused by a combination of low neonatal blood pressure and birth trauma.²⁴ Ragland and colleagues²⁵ reported on 24 cases of neonatal CS; in only 1 case was the diagnosis made within 24 hours.They described a “sentinel skin lesion” on the forearm of each patient as the sign of neonatal CS. Late diagnosis results in contracture and growth arrest of the involved extremity. In their series, only 1 patient underwent fasciotomy within 24 hours, and it resulted in a good functional outcome. High clinical suspicion is the key to early diagnosis and treatment of this rare pathology.

Medical problems that cause intracompartmental bleeding (hepatic failure, renal failure, leukemia, hemophilia) have been cited as causing CS.^26-28 CS may be the first symptom of occult hemophilia²⁹ Correction of the coagulation defect may take priority over surgical treatment in these cases, though the decision should be made on a case-by-case basis.²⁶

CS in children can also be caused by snakebites. Shaw and Hosalkar³⁰ reported on successful use of antivenin in preventing the need for surgical treatment in 16 of 19 patients with rattlesnake bites. Two patients had limited surgical débridement, and 1 underwent fasciotomy for CS. The authors recommended using antivenin to prevent CS in children with snakebites.³⁰

Prasarn and colleagues² reported on 12 cases of upper extremity CS in children in the absence of fractures. Of the 12 patients, 10 were managed in an intensive care unit and had an obtunded sensorium. Etiology in 7 (58%) of the 12 cases was iatrogenic (intravenous infiltration, retained phlebotomy tourniquet). In this series, 4 amputations were performed on affected extremities.

Diagnosis

Identification of evolving CS in a child is difficult because of the child’s limited ability to communicate and anxiety about being examined by a stranger. Orthopedists are trained to look for the 5 Ps (pain, paresthesia, paralysis, pallor, pulselessness) associated with CS. Examining an anxious, frightened young child is difficult, and documenting the degree of pain is not practical in a child who may not be able or willing to communicate effectively.

In a series of 33 children with CS, Bae and colleagues³¹ found that the 5 Ps were relatively unreliable in making a timely diagnosis. The authors also found that increased analgesic use was documented a mean of 7.3 hours before a change in vascular status and that it was a more sensitive indicator of CS in children. The resulting recommendation is that children at risk for CS be closely monitored for the 3 As (increasing analgesic requirement, anxiety, agitation).³²

Regional anesthesia is used to control postoperative pain in adults and children.^33,34 Injudicious use may mask the primary symptom (pain) of CS.^32,35-38 Use of regional anesthesia in patients at high risk for CS is highly discouraged.

Although CS is a clinical diagnosis, compartment pressure measurements can be useful in making decisions in certain clinical scenarios. In an obtunded child or in a child with severe mental and communication disability, such a measurement can help confirm or rule out the diagnosis.

Normal compartment pressures are higher in children than in adults. Staudt and colleagues³⁹ compared pressures in 4 lower leg compartments of 20 healthy children and 20 healthy adults. Mean pressure varied from 13.3 mm Hg to 16.6 mm Hg in children and from 5.2 mm Hg to 9.7 mm Hg in adults—indicating higher normal pressure in lower leg compartments in children.

Compartment pressures were reported highest within 5 cm of the fracture site.⁴⁰ When clinically indicated, they should be measured in that area in an injured extremity. The pressure threshold that requires fasciotomy is debatable. Intracompartmental pressures of 30 to 45 mm Hg, or measurements less than 30 mm Hg of diastolic blood pressure (pressure change = diastolic blood pressure – compartment pressure), have been recommended as cutoffs by some authors.^41-44 As resting normal compartment pressures are higher in children, these cutoffs cannot be used as reliably in children as in adults. Direct measurement of intracompartmental pressure is invasive and can be difficult in an agitated, awake child. The potential utility of near-infrared spectroscopy in the diagnosis of increased compartment pressure has been reported.^45,46 This method uses differential light absorption properties of oxygenated hemoglobin to measure tissue ischemia—similar to the method used in pulse oximetry. Compared with pulse oximetry, near-infrared spectroscopy can sample deeper tissue (3 cm below skin level). Shuler and colleagues⁴⁵ reported near-infrared spectroscopy findings for 14 adults with acute CS. Lower tissue oxygenation levels correlated with increased intracompartmental pressures, but the authors could not define a cutoff for which near-infrared spectroscopy measurements would indicate significant tissue ischemia. Use of this method in diagnosing CS in children was described in a case report.⁴⁶

CS remains a clinical diagnosis. Informing family and staff about the signs and symptoms of this syndrome and closely monitoring analgesic use in these patients are crucial. Compartment pressure measurements can be used when the diagnosis is unclear, particularly in noncommunicative patients, but these values should be interpreted with caution.

Treatment

Once CS is diagnosed, emergent fasciotomy and decompression are indicated. Surgeons planning fasciotomy should be aware of the definitive treatment of the CS etiology. Treatment of clotting deficiency in cases caused by excessive bleeding, fracture fixation, and vascular repair may be indicated during fasciotomy and decompression.

Summary

Increased need for analgesics is often the first sign of CS in children and should be considered the sentinel alarm for ongoing tissue necrosis. CS remains a clinical diagnosis, and compartment pressure should be measured only as a confirmatory test in noncommunicative patients or when the diagnosis is unclear. Children with supracondylar humeral fractures, forearm fractures, tibial fractures, and medical risk factors for coagulopathy are at increased risk and should be monitored closely. When the diagnosis is made promptly and the condition is treated with fasciotomy, good long-term clinical results can be expected.

 Compartment syndrome (CS) is one of the true orthopedic emergencies. Identifying the high-risk patient, making a prompt diagnosis, and initiating effective treatment are the crucial steps in avoiding a poor outcome. A physician’s inability to communicate with young children can interfere with diagnosing CS in a timely fashion. Many young patients in hospitals are admitted to pediatric floors where routine orthopedic care is not the norm and staff are unfamiliar with the signs and symptoms of evolving CS. As orthopedic surgeons are often involved in caring for these patients, they should be aware of the aspects of CS that are unique to children and should be able to identify patients who are at risk and would benefit from close monitoring. In addition, given the consequences of late diagnosis, early diagnosis is important from a medicolegal standpoint. Only 44% of cases of adult and pediatric CS are decided in favor of treating physicians, compared with 75% of cases in other orthopedic malpractice claims.1,2

Risk Factors for Posttraumatic Compartment Syndrome

Supracondylar Humeral Fracture

CS is a well-described complication of this injury. CS develops in 0.1% to 0.3% of children who present with supracondylar humeral fracture.^3,4 Casted elbow flexion beyond 90° and concomitant vascular injury put these children at increased risk for CS. Mubarak and Carroll⁵ reported 9 cases of CS in the volar compartment of the forearm after an extension-type supracondylar humeral fracture and attributed 8 of them to elbow flexion beyond 90° after closed reduction. In 29 children with supracondylar humeral fracture,Battaglia and colleagues³ found the highest compartment pressure in the deep volar compartment, especially near the fracture site, as well as a significant increase in pressure with the elbow flexed beyond 90°.

In a study of children with supracondylar humeral fracture, Choi and colleagues⁶ found 2 cases of CS among 9 patients who presented with a pulseless, poorly perfused hand and no cases of CS among 24 patients who presented with a pulseless but well-perfused hand.

Studies have found that a treatment delay of 8 to 12 hours did not increase the rate of CS in Gartland type 2 and type 3 fractures.^7-10 The investigators in these studies did not recommend delaying treatment of patients with neurologic deficit and absent radial pulse. Ramachandran and colleagues4 reported 11 cases of CS in patients with low-energy supracondylar humeral fracture and intact radial pulse at presentation. The patients who developed CS presented with severe swelling, and their mean treatment delay was 22 hours (range, 6-64 hours). Given the data, we do not recommend delayed treatment for children with supracondylar humeral fracture and neurologic deficit or absent pulse. We do recommend close inpatient preoperative monitoring of patients with severe swelling.

CS after supracondylar humeral fracture is mostly seen in the volar compartment of the forearm, but it has also been reported in the mobile wad, the anterior arm compartment, and the posterior arm compartment.^11,12

Floating Elbow

CS has been reported in children with ipsilateral humeral and forearm fractures. Blakemore and colleagues¹³ reported a 33% rate of CS in children with displaced distal humeral and forearm fractures. A retrospective review of 16 cases of floating elbow treated at Boston Children’s Hospital found CS in 2 patients and incipient CS in 4 of 10 patients with forearm fractures treated with closed reduction and plaster casting. There were no signs of CS in 6 patients with distal humeral and forearm fractures stabilized with Kirschner wires.¹⁴ Given the data, we do not recommend circumferential casting for forearm fractures in children with floating elbow.

Forearm Fracture

Haasbeek and Cole¹⁵ reported CS in 5 (11%) of 46 children with open forearm fracture. Yuan and colleagues¹⁶ reported CS in 3 (6%) of 50 open forearm fractures and 3 of 30 closed fractures treated with closed reduction and intramedullary nailing. They found increased risk for CS in patients with longer operative time, indicating prolonged closed manipulation of these fractures as a risk factor for CS. They did not find any cases of CS among 205 forearm fractures treated with closed reduction and casting.

Flynn and colleagues17 reported CS in 2 of 30 patients treated with intramedullary nailing within 24 hours of injury and in 0 of 73 patients treated after 24 hours.

Blackman and colleagues¹⁸ reported CS in 3 (7.7%) of 39 open forearm fractures and 0 of 74 closed fractures treated operatively. In their series, a small incision was made to facilitate reduction in 38 (51.4%) of 74 closed fractures to decrease closed manipulation and operative time. The rate of CS after intramedullary nailing of closed forearm fractures was lower in this series than in similar reports in the literature.

Reported data indicate increased risk for CS in children with open forearm fractures and fractures treated with closed reduction and intramedullary nailing, especially performed within 24 hours of injury, and prolonged closed manipulation performed during surgery. We recommend close monitoring of all children with operatively treated forearm fractures and, in particular, children with the risk factors mentioned.

Femoral Fracture

Although CS after femoral shaft fractures is not common, CS has been reported after 90/90 spica casting of femoral shaft fractures in children. Mubarak and colleagues19 reported on 9 children who developed calf CS after treatment of femoral shaft fracture in 90/90 spica casts. The technique used in 7 of the 9 reported cases involved initial application of a short leg cast and then traction applied to the leg—believed to cause impinging of the cast on the posterior compartment of the leg. The authors recommended an alternative method of applying spica casts, which is beyond the scope of this review.

Tibial Fracture

Children with tibial fracture, especially a fracture sustained in a motor vehicle accident, are at risk for CS. Hope and Cole²⁰ found CS in 4 (4%) of 92 children with open tibial fracture.

Children with tibial tubercle fracture are at increased risk for CS because of concomitant vascular injury. Pandya and colleagues²¹ reported CS or vascular compromise in 4 of 40 patients with tibial tubercle fracture. We recommend close monitoring for signs of impending CS in children who present with high-energy tibial shaft fracture and tibial tubercle fracture.

Flynn and colleagues²² reported outcomes of 43 cases of acute CS of the leg in children treated at 2 pediatric trauma centers. Mean time from injury to fasciotomy was 20.5 hours (range, 3.9-118 hours). Functional outcome was excellent at time of follow-up; 41 of 43 cases had no sequelae, and the 2 patients who lost function underwent fasciotomy more than 80 hours after injury. Despite the long interval between injury and surgery, excellent results were achieved with fasciotomy, suggesting an increased potential for recovery in the pediatric population.

Mubarak²³ reported on 6 cases of distal tibial physis fracture in patients who presented with severe pain and swelling of the ankle, hyposthesia of the first web space, weakness of the extensor hallucis longus and extensor digitorum communis, and pain on passive flexion of the toes. In all these patients, intramuscular pressure was more than 40 mm Hg beneath the extensor retinaculum and less than 20 mm Hg in the anterior compartment. All patients experienced prompt relief of pain and improved sensation and strength within 24 hours after release of the superior extensor retinaculum and fracture stabilization.

Miscellaneous and Nontraumatic Causes of Compartment Syndrome

Neonatal CS is very rare, and diagnosis is often missed. Neonatal CS is thought to be caused by a combination of low neonatal blood pressure and birth trauma.²⁴ Ragland and colleagues²⁵ reported on 24 cases of neonatal CS; in only 1 case was the diagnosis made within 24 hours.They described a “sentinel skin lesion” on the forearm of each patient as the sign of neonatal CS. Late diagnosis results in contracture and growth arrest of the involved extremity. In their series, only 1 patient underwent fasciotomy within 24 hours, and it resulted in a good functional outcome. High clinical suspicion is the key to early diagnosis and treatment of this rare pathology.

Medical problems that cause intracompartmental bleeding (hepatic failure, renal failure, leukemia, hemophilia) have been cited as causing CS.^26-28 CS may be the first symptom of occult hemophilia²⁹ Correction of the coagulation defect may take priority over surgical treatment in these cases, though the decision should be made on a case-by-case basis.²⁶

CS in children can also be caused by snakebites. Shaw and Hosalkar³⁰ reported on successful use of antivenin in preventing the need for surgical treatment in 16 of 19 patients with rattlesnake bites. Two patients had limited surgical débridement, and 1 underwent fasciotomy for CS. The authors recommended using antivenin to prevent CS in children with snakebites.³⁰

Prasarn and colleagues² reported on 12 cases of upper extremity CS in children in the absence of fractures. Of the 12 patients, 10 were managed in an intensive care unit and had an obtunded sensorium. Etiology in 7 (58%) of the 12 cases was iatrogenic (intravenous infiltration, retained phlebotomy tourniquet). In this series, 4 amputations were performed on affected extremities.

Diagnosis

Identification of evolving CS in a child is difficult because of the child’s limited ability to communicate and anxiety about being examined by a stranger. Orthopedists are trained to look for the 5 Ps (pain, paresthesia, paralysis, pallor, pulselessness) associated with CS. Examining an anxious, frightened young child is difficult, and documenting the degree of pain is not practical in a child who may not be able or willing to communicate effectively.

In a series of 33 children with CS, Bae and colleagues³¹ found that the 5 Ps were relatively unreliable in making a timely diagnosis. The authors also found that increased analgesic use was documented a mean of 7.3 hours before a change in vascular status and that it was a more sensitive indicator of CS in children. The resulting recommendation is that children at risk for CS be closely monitored for the 3 As (increasing analgesic requirement, anxiety, agitation).³²

Regional anesthesia is used to control postoperative pain in adults and children.^33,34 Injudicious use may mask the primary symptom (pain) of CS.^32,35-38 Use of regional anesthesia in patients at high risk for CS is highly discouraged.

Although CS is a clinical diagnosis, compartment pressure measurements can be useful in making decisions in certain clinical scenarios. In an obtunded child or in a child with severe mental and communication disability, such a measurement can help confirm or rule out the diagnosis.

Normal compartment pressures are higher in children than in adults. Staudt and colleagues³⁹ compared pressures in 4 lower leg compartments of 20 healthy children and 20 healthy adults. Mean pressure varied from 13.3 mm Hg to 16.6 mm Hg in children and from 5.2 mm Hg to 9.7 mm Hg in adults—indicating higher normal pressure in lower leg compartments in children.

Compartment pressures were reported highest within 5 cm of the fracture site.⁴⁰ When clinically indicated, they should be measured in that area in an injured extremity. The pressure threshold that requires fasciotomy is debatable. Intracompartmental pressures of 30 to 45 mm Hg, or measurements less than 30 mm Hg of diastolic blood pressure (pressure change = diastolic blood pressure – compartment pressure), have been recommended as cutoffs by some authors.^41-44 As resting normal compartment pressures are higher in children, these cutoffs cannot be used as reliably in children as in adults. Direct measurement of intracompartmental pressure is invasive and can be difficult in an agitated, awake child. The potential utility of near-infrared spectroscopy in the diagnosis of increased compartment pressure has been reported.^45,46 This method uses differential light absorption properties of oxygenated hemoglobin to measure tissue ischemia—similar to the method used in pulse oximetry. Compared with pulse oximetry, near-infrared spectroscopy can sample deeper tissue (3 cm below skin level). Shuler and colleagues⁴⁵ reported near-infrared spectroscopy findings for 14 adults with acute CS. Lower tissue oxygenation levels correlated with increased intracompartmental pressures, but the authors could not define a cutoff for which near-infrared spectroscopy measurements would indicate significant tissue ischemia. Use of this method in diagnosing CS in children was described in a case report.⁴⁶

CS remains a clinical diagnosis. Informing family and staff about the signs and symptoms of this syndrome and closely monitoring analgesic use in these patients are crucial. Compartment pressure measurements can be used when the diagnosis is unclear, particularly in noncommunicative patients, but these values should be interpreted with caution.

Treatment

Once CS is diagnosed, emergent fasciotomy and decompression are indicated. Surgeons planning fasciotomy should be aware of the definitive treatment of the CS etiology. Treatment of clotting deficiency in cases caused by excessive bleeding, fracture fixation, and vascular repair may be indicated during fasciotomy and decompression.

Summary

Increased need for analgesics is often the first sign of CS in children and should be considered the sentinel alarm for ongoing tissue necrosis. CS remains a clinical diagnosis, and compartment pressure should be measured only as a confirmatory test in noncommunicative patients or when the diagnosis is unclear. Children with supracondylar humeral fractures, forearm fractures, tibial fractures, and medical risk factors for coagulopathy are at increased risk and should be monitored closely. When the diagnosis is made promptly and the condition is treated with fasciotomy, good long-term clinical results can be expected.

 Compartment syndrome (CS) is one of the true orthopedic emergencies. Identifying the high-risk patient, making a prompt diagnosis, and initiating effective treatment are the crucial steps in avoiding a poor outcome. A physician’s inability to communicate with young children can interfere with diagnosing CS in a timely fashion. Many young patients in hospitals are admitted to pediatric floors where routine orthopedic care is not the norm and staff are unfamiliar with the signs and symptoms of evolving CS. As orthopedic surgeons are often involved in caring for these patients, they should be aware of the aspects of CS that are unique to children and should be able to identify patients who are at risk and would benefit from close monitoring. In addition, given the consequences of late diagnosis, early diagnosis is important from a medicolegal standpoint. Only 44% of cases of adult and pediatric CS are decided in favor of treating physicians, compared with 75% of cases in other orthopedic malpractice claims.1,2

Risk Factors for Posttraumatic Compartment Syndrome

Supracondylar Humeral Fracture

CS is a well-described complication of this injury. CS develops in 0.1% to 0.3% of children who present with supracondylar humeral fracture.^3,4 Casted elbow flexion beyond 90° and concomitant vascular injury put these children at increased risk for CS. Mubarak and Carroll⁵ reported 9 cases of CS in the volar compartment of the forearm after an extension-type supracondylar humeral fracture and attributed 8 of them to elbow flexion beyond 90° after closed reduction. In 29 children with supracondylar humeral fracture,Battaglia and colleagues³ found the highest compartment pressure in the deep volar compartment, especially near the fracture site, as well as a significant increase in pressure with the elbow flexed beyond 90°.

In a study of children with supracondylar humeral fracture, Choi and colleagues⁶ found 2 cases of CS among 9 patients who presented with a pulseless, poorly perfused hand and no cases of CS among 24 patients who presented with a pulseless but well-perfused hand.

Studies have found that a treatment delay of 8 to 12 hours did not increase the rate of CS in Gartland type 2 and type 3 fractures.^7-10 The investigators in these studies did not recommend delaying treatment of patients with neurologic deficit and absent radial pulse. Ramachandran and colleagues4 reported 11 cases of CS in patients with low-energy supracondylar humeral fracture and intact radial pulse at presentation. The patients who developed CS presented with severe swelling, and their mean treatment delay was 22 hours (range, 6-64 hours). Given the data, we do not recommend delayed treatment for children with supracondylar humeral fracture and neurologic deficit or absent pulse. We do recommend close inpatient preoperative monitoring of patients with severe swelling.

CS after supracondylar humeral fracture is mostly seen in the volar compartment of the forearm, but it has also been reported in the mobile wad, the anterior arm compartment, and the posterior arm compartment.^11,12

Floating Elbow

CS has been reported in children with ipsilateral humeral and forearm fractures. Blakemore and colleagues¹³ reported a 33% rate of CS in children with displaced distal humeral and forearm fractures. A retrospective review of 16 cases of floating elbow treated at Boston Children’s Hospital found CS in 2 patients and incipient CS in 4 of 10 patients with forearm fractures treated with closed reduction and plaster casting. There were no signs of CS in 6 patients with distal humeral and forearm fractures stabilized with Kirschner wires.¹⁴ Given the data, we do not recommend circumferential casting for forearm fractures in children with floating elbow.

Forearm Fracture

Haasbeek and Cole¹⁵ reported CS in 5 (11%) of 46 children with open forearm fracture. Yuan and colleagues¹⁶ reported CS in 3 (6%) of 50 open forearm fractures and 3 of 30 closed fractures treated with closed reduction and intramedullary nailing. They found increased risk for CS in patients with longer operative time, indicating prolonged closed manipulation of these fractures as a risk factor for CS. They did not find any cases of CS among 205 forearm fractures treated with closed reduction and casting.

Flynn and colleagues17 reported CS in 2 of 30 patients treated with intramedullary nailing within 24 hours of injury and in 0 of 73 patients treated after 24 hours.

Blackman and colleagues¹⁸ reported CS in 3 (7.7%) of 39 open forearm fractures and 0 of 74 closed fractures treated operatively. In their series, a small incision was made to facilitate reduction in 38 (51.4%) of 74 closed fractures to decrease closed manipulation and operative time. The rate of CS after intramedullary nailing of closed forearm fractures was lower in this series than in similar reports in the literature.

Reported data indicate increased risk for CS in children with open forearm fractures and fractures treated with closed reduction and intramedullary nailing, especially performed within 24 hours of injury, and prolonged closed manipulation performed during surgery. We recommend close monitoring of all children with operatively treated forearm fractures and, in particular, children with the risk factors mentioned.

Femoral Fracture

Although CS after femoral shaft fractures is not common, CS has been reported after 90/90 spica casting of femoral shaft fractures in children. Mubarak and colleagues19 reported on 9 children who developed calf CS after treatment of femoral shaft fracture in 90/90 spica casts. The technique used in 7 of the 9 reported cases involved initial application of a short leg cast and then traction applied to the leg—believed to cause impinging of the cast on the posterior compartment of the leg. The authors recommended an alternative method of applying spica casts, which is beyond the scope of this review.

Tibial Fracture

Children with tibial fracture, especially a fracture sustained in a motor vehicle accident, are at risk for CS. Hope and Cole²⁰ found CS in 4 (4%) of 92 children with open tibial fracture.

Children with tibial tubercle fracture are at increased risk for CS because of concomitant vascular injury. Pandya and colleagues²¹ reported CS or vascular compromise in 4 of 40 patients with tibial tubercle fracture. We recommend close monitoring for signs of impending CS in children who present with high-energy tibial shaft fracture and tibial tubercle fracture.

Flynn and colleagues²² reported outcomes of 43 cases of acute CS of the leg in children treated at 2 pediatric trauma centers. Mean time from injury to fasciotomy was 20.5 hours (range, 3.9-118 hours). Functional outcome was excellent at time of follow-up; 41 of 43 cases had no sequelae, and the 2 patients who lost function underwent fasciotomy more than 80 hours after injury. Despite the long interval between injury and surgery, excellent results were achieved with fasciotomy, suggesting an increased potential for recovery in the pediatric population.

Mubarak²³ reported on 6 cases of distal tibial physis fracture in patients who presented with severe pain and swelling of the ankle, hyposthesia of the first web space, weakness of the extensor hallucis longus and extensor digitorum communis, and pain on passive flexion of the toes. In all these patients, intramuscular pressure was more than 40 mm Hg beneath the extensor retinaculum and less than 20 mm Hg in the anterior compartment. All patients experienced prompt relief of pain and improved sensation and strength within 24 hours after release of the superior extensor retinaculum and fracture stabilization.

Miscellaneous and Nontraumatic Causes of Compartment Syndrome

Neonatal CS is very rare, and diagnosis is often missed. Neonatal CS is thought to be caused by a combination of low neonatal blood pressure and birth trauma.²⁴ Ragland and colleagues²⁵ reported on 24 cases of neonatal CS; in only 1 case was the diagnosis made within 24 hours.They described a “sentinel skin lesion” on the forearm of each patient as the sign of neonatal CS. Late diagnosis results in contracture and growth arrest of the involved extremity. In their series, only 1 patient underwent fasciotomy within 24 hours, and it resulted in a good functional outcome. High clinical suspicion is the key to early diagnosis and treatment of this rare pathology.

Medical problems that cause intracompartmental bleeding (hepatic failure, renal failure, leukemia, hemophilia) have been cited as causing CS.^26-28 CS may be the first symptom of occult hemophilia²⁹ Correction of the coagulation defect may take priority over surgical treatment in these cases, though the decision should be made on a case-by-case basis.²⁶

CS in children can also be caused by snakebites. Shaw and Hosalkar³⁰ reported on successful use of antivenin in preventing the need for surgical treatment in 16 of 19 patients with rattlesnake bites. Two patients had limited surgical débridement, and 1 underwent fasciotomy for CS. The authors recommended using antivenin to prevent CS in children with snakebites.³⁰

Prasarn and colleagues² reported on 12 cases of upper extremity CS in children in the absence of fractures. Of the 12 patients, 10 were managed in an intensive care unit and had an obtunded sensorium. Etiology in 7 (58%) of the 12 cases was iatrogenic (intravenous infiltration, retained phlebotomy tourniquet). In this series, 4 amputations were performed on affected extremities.

Diagnosis

Identification of evolving CS in a child is difficult because of the child’s limited ability to communicate and anxiety about being examined by a stranger. Orthopedists are trained to look for the 5 Ps (pain, paresthesia, paralysis, pallor, pulselessness) associated with CS. Examining an anxious, frightened young child is difficult, and documenting the degree of pain is not practical in a child who may not be able or willing to communicate effectively.

In a series of 33 children with CS, Bae and colleagues³¹ found that the 5 Ps were relatively unreliable in making a timely diagnosis. The authors also found that increased analgesic use was documented a mean of 7.3 hours before a change in vascular status and that it was a more sensitive indicator of CS in children. The resulting recommendation is that children at risk for CS be closely monitored for the 3 As (increasing analgesic requirement, anxiety, agitation).³²

Regional anesthesia is used to control postoperative pain in adults and children.^33,34 Injudicious use may mask the primary symptom (pain) of CS.^32,35-38 Use of regional anesthesia in patients at high risk for CS is highly discouraged.

Although CS is a clinical diagnosis, compartment pressure measurements can be useful in making decisions in certain clinical scenarios. In an obtunded child or in a child with severe mental and communication disability, such a measurement can help confirm or rule out the diagnosis.

Normal compartment pressures are higher in children than in adults. Staudt and colleagues³⁹ compared pressures in 4 lower leg compartments of 20 healthy children and 20 healthy adults. Mean pressure varied from 13.3 mm Hg to 16.6 mm Hg in children and from 5.2 mm Hg to 9.7 mm Hg in adults—indicating higher normal pressure in lower leg compartments in children.

Compartment pressures were reported highest within 5 cm of the fracture site.⁴⁰ When clinically indicated, they should be measured in that area in an injured extremity. The pressure threshold that requires fasciotomy is debatable. Intracompartmental pressures of 30 to 45 mm Hg, or measurements less than 30 mm Hg of diastolic blood pressure (pressure change = diastolic blood pressure – compartment pressure), have been recommended as cutoffs by some authors.^41-44 As resting normal compartment pressures are higher in children, these cutoffs cannot be used as reliably in children as in adults. Direct measurement of intracompartmental pressure is invasive and can be difficult in an agitated, awake child. The potential utility of near-infrared spectroscopy in the diagnosis of increased compartment pressure has been reported.^45,46 This method uses differential light absorption properties of oxygenated hemoglobin to measure tissue ischemia—similar to the method used in pulse oximetry. Compared with pulse oximetry, near-infrared spectroscopy can sample deeper tissue (3 cm below skin level). Shuler and colleagues⁴⁵ reported near-infrared spectroscopy findings for 14 adults with acute CS. Lower tissue oxygenation levels correlated with increased intracompartmental pressures, but the authors could not define a cutoff for which near-infrared spectroscopy measurements would indicate significant tissue ischemia. Use of this method in diagnosing CS in children was described in a case report.⁴⁶

CS remains a clinical diagnosis. Informing family and staff about the signs and symptoms of this syndrome and closely monitoring analgesic use in these patients are crucial. Compartment pressure measurements can be used when the diagnosis is unclear, particularly in noncommunicative patients, but these values should be interpreted with caution.

Treatment

Once CS is diagnosed, emergent fasciotomy and decompression are indicated. Surgeons planning fasciotomy should be aware of the definitive treatment of the CS etiology. Treatment of clotting deficiency in cases caused by excessive bleeding, fracture fixation, and vascular repair may be indicated during fasciotomy and decompression.

Summary

Increased need for analgesics is often the first sign of CS in children and should be considered the sentinel alarm for ongoing tissue necrosis. CS remains a clinical diagnosis, and compartment pressure should be measured only as a confirmatory test in noncommunicative patients or when the diagnosis is unclear. Children with supracondylar humeral fractures, forearm fractures, tibial fractures, and medical risk factors for coagulopathy are at increased risk and should be monitored closely. When the diagnosis is made promptly and the condition is treated with fasciotomy, good long-term clinical results can be expected.

Blount disease (tibia vara) is an angular tibia deformity that includes varus, increased posterior slope, and internal rotation. This deformity was first described in 1922 by Erlacher1 in Germany. In 1937, Walter Blount2 reported on it in the United States. It is the most common cause of pathologic genu varum in adolescence and childhood.

An oblique incomplete closing wedge osteotomy of the proximal tibial metaphysis was described by Wagner³ for the treatment of unicompartmental osteoarthrosis of the knee in adults. Laurencin and colleagues⁴ applied this technique to the treatment of pediatric tibia vara with favorable results. They spared the medial cortex of the tibia in their incomplete closing wedge osteotomy technique. In each of the 9 cases we treated and describe here, we accidentally completed the tibial osteotomy when attempting the Laurencin technique. Given that the osteotomy was completed, we modified the Laurencin technique by using a 6-hole, 4.5-mm compression plate rather than a 5-hole semitubular plate, and added a large oblique screw from the medial side to compress the osteotomy site and to protect the plate from fracture. In addition, in 2 patients who weighed more than 250 pounds, we used an external fixator for additional stability. In this article, we report the outcomes of correcting adolescent tibia vara with a complete closing wedge tibial osteotomy and an oblique fibular osteotomy.

Materials and Methods

This study was approved by the Institutional Review Board at Pennsylvania State University. Between 2009 and 2012, we performed 9 complete oblique proximal tibial lateral closing wedge osteotomies on 8 patients (2 girls, 6 boys). In each case, the primary diagnosis was Blount disease. One patient also had renal dysplasia and was receiving dialysis. Mean age at time of operation was 15 years (range, 13-17 years). Mean preoperative weight was 215 pounds (range, 119-317 lb). Mean weight gain at follow-up was 4.39 pounds (range, –10 to 19 lb). Mean body mass index (BMI) was 38 (range, 25-48) (Table). All patients had varus angulation of the proximal tibia before surgery. Mean preoperative varus on standing films was 22° (range, 10°-36°). Because of the patients’ size, we used standing long-leg radiographs, on individual cassettes, for each leg.

Surgical Technique

Before surgery, we use paper cutouts to template the osteotomy wedge. We also use perioperative antibiotics and a standard time-out. For visualization of the entire leg for accurate correction, we prepare and drape the entire leg. A sterile tourniquet is used. At the midshaft of the fibula, a 4-cm incision is made, and dissection is carefully carried down to the fibula. Subperiosteal dissection is performed about the fibula, allowing adequate clearance for an oblique osteotomy. The osteotomy removes about 1 cm of fibula, which is to be used as bone graft for the tibial osteotomy. In addition, a lateral compartment fasciotomy is performed to prevent swelling-related complications. The wound is irrigated and injected with bupivacaine and closed in routine fashion.

We then make an inverted hockey-stick incision over the proximal tibia, centered down to the tibial tubercle. After dissecting down to the anterior compartment, we perform a fasciotomy of about 8 cm to accommodate swelling. Subperiosteal dissection is then performed around the proximal tibia. The medial soft tissues are left attached to increase blood supply and healing. During subperiosteal dissection, soft elevators are used to gently retract the lateral soft tissues along with the inferior and posterior structures. We use fluoroscopic imaging to guide the osteotomy as well as screw and plate placement. We use a 6-hole, 4.5-mm compression plate and screws for fixation. The 2 proximal screws of the plate are predrilled in place to allow for application of the plate after completion of the osteotomy. The plate is then rotated out of position on 1 screw, and the osteotomy is identified under fluoroscopy with the appropriate position distal to the second hole of the 6-hole plate.

An oscillating saw and osteotomes are used to perform the oblique osteotomy. The pre-estimated bone wedge is removed. Wedge size is adjusted, if needed. The bone wedge is morselized for bone graft. The osteotomy is then closed, correcting both varus and internal tibial torsion. Our goal is 5° valgus. After correction is obtained, the plate is placed, and the proximal screw is snugly seated. Three cortical screws are placed distally to hold the plate in place under compression mode, and a cancellous screw is placed superiorly at the proximal portion of the plate for additional fixation. The screw placed proximal to the osteotomy site is a fully threaded cortical screw with excellent compression. Correction and proper placement of hardware are verified with fluoroscopy.

The wound is irrigated and injected with bupivacaine. Bone graft is then placed at the osteotomy site. Additional bone graft is placed posteriorly between the osteotomy site and the muscle mass to stimulate additional healing. Another screw is placed obliquely from the medial side across the osteotomy site to provide additional fixation (Figure 1).

Copyright belongs to the authors

A deep drain is placed and connected to bulb suction for 24 hours after surgery. The wound is then closed in routine fashion. In 2 patients who weighed more than 250 pounds, we used an external fixator for additional stability (Figure 2).

Copyright belongs to the authors

Postoperative Care

The incisions are dressed with antibiotic ointment and 4×4-in bandages and then wrapped with sterile cotton under-cast padding. The leg is placed into a well-padded cylinder cast with the knee flexed 10°. The leg is aligned to about 5° valgus. The cast is then split on the side and spread to allow for swelling and to prevent compartment syndrome.⁵ We also use a drain hooked to bulb suction, which is removed 24 hours after surgery. Toe-touch weight-bearing with crutches is allowed immediately after surgery. The cast is removed at 6 weeks, and a hinged range-of-motion knee brace is worn for another 6 weeks. All patients are allowed to resume normal activity after 4 months. In our 2 external-fixator cases, a cast was not used, and toe-touch weight-bearing and knee motion were allowed immediately. The external fixators were removed at about 10 weeks.

Results

Mean postoperative mechanical femoral-tibial angle was 3°, and mean correction was 26° (range, 16°-43°) (Table). Lateral distal femoral angle did not show significant femoral deformity in our sample. Mean medial proximal tibial angle was 74° (range, 63°-79°). In each case, the varus deformity was primarily in the tibia. Mean tourniquet time was 88 minutes (range, 50-119 min). Our complication rate was 11% (1 knee). In our first case, in which we did not use an extra medial screw, the 4.5-mm plate fractured at the osteotomy site 2.5 months after surgery. The 250-pound patient subsequently lost 17° of correction, and valgus alignment was not achieved. Preoperative varus was 25°, and postoperative alignment was 8° varus. This plate fracture led us to use an extra medial screw for additional stability in all subsequent cases and to consider using an external fixator for patients weighing more than 250 pounds. After the first case, there were no other plate fractures. A potential problem with closing wedge osteotomy is shortening, but varus correction restores some length. Mean postoperative leg-length difference was 10 mm (range, 0-16 mm). No patient complained of leg-length difference during the postoperative follow-up.

Eight and a half months after surgery, 1 patient had hardware removed, at the family’s request. No patient experienced perioperative infection or neurovascular damage. Our overall patient population was obese—mean BMI was 38 (range, 25-48), and mean postoperative weight was 219 pounds. Three of our 8 patients were overweight (BMI, 25-30), and 5 were obese (BMI, >30). For prevention of plate failure, we recommend using an extra oblique screw in all patients and considering an external fixator for patients who weigh more than 250 pounds.

Discussion

Correction of adolescent tibia vara can be challenging because of patient obesity. The technique described here—a modification of the technique of Laurencin and colleagues⁴—is practical and reproducible in this population. The goals in performing osteotomy are to correct the deformity, restore joint alignment, preserve leg length, and prevent recurrent deformity and other complications, such as neurovascular injury, nonunion, and infection.^3,6-8 Our technique minimizes the risk for these complications. For example, the fasciotomy provides excellent decompression of the anterior and lateral compartments, minimizing neurovascular ischemia and the risk for compartment syndrome. During cast placement, splitting and spreading reduce the risk for compartment syndrome as well.⁵

Wagner3,9 demonstrated the utility of a closing wedge proximal tibial osteotomy in adults. Laurencin and colleagues4 showed this technique is effective in correcting tibia vara in a pediatric population. However, they did not specify patient weight and used a small semitubular plate for fixation, and some of their patients had infantile Blount disease. We modified the technique in 3 ways. First, we performed a complete osteotomy. Second, because our patients were adolescents and very large, we used a 6-hole, 4.5-mm compression plate and screws. Third, we used an external fixator for increased stability in patients who weighed more than 250 pounds.

The reported technique, using an oblique metaphyseal closing wedge osteotomy with internal fixation in obese patients, is practical, safe, and reliable. This technique is a useful alternative to an external fixator. We used it on 9 knees with tibia vara, and it was completely successful in 8 cases and partially successful in 1 (hardware breakage occurred). An external fixator was used to prevent hardware breakage in 2 patients who weighed more than 250 pounds. This technique is a valuable treatment option for surgical correction, especially in obese patients.

Blount disease (tibia vara) is an angular tibia deformity that includes varus, increased posterior slope, and internal rotation. This deformity was first described in 1922 by Erlacher1 in Germany. In 1937, Walter Blount2 reported on it in the United States. It is the most common cause of pathologic genu varum in adolescence and childhood.

An oblique incomplete closing wedge osteotomy of the proximal tibial metaphysis was described by Wagner³ for the treatment of unicompartmental osteoarthrosis of the knee in adults. Laurencin and colleagues⁴ applied this technique to the treatment of pediatric tibia vara with favorable results. They spared the medial cortex of the tibia in their incomplete closing wedge osteotomy technique. In each of the 9 cases we treated and describe here, we accidentally completed the tibial osteotomy when attempting the Laurencin technique. Given that the osteotomy was completed, we modified the Laurencin technique by using a 6-hole, 4.5-mm compression plate rather than a 5-hole semitubular plate, and added a large oblique screw from the medial side to compress the osteotomy site and to protect the plate from fracture. In addition, in 2 patients who weighed more than 250 pounds, we used an external fixator for additional stability. In this article, we report the outcomes of correcting adolescent tibia vara with a complete closing wedge tibial osteotomy and an oblique fibular osteotomy.

Materials and Methods

This study was approved by the Institutional Review Board at Pennsylvania State University. Between 2009 and 2012, we performed 9 complete oblique proximal tibial lateral closing wedge osteotomies on 8 patients (2 girls, 6 boys). In each case, the primary diagnosis was Blount disease. One patient also had renal dysplasia and was receiving dialysis. Mean age at time of operation was 15 years (range, 13-17 years). Mean preoperative weight was 215 pounds (range, 119-317 lb). Mean weight gain at follow-up was 4.39 pounds (range, –10 to 19 lb). Mean body mass index (BMI) was 38 (range, 25-48) (Table). All patients had varus angulation of the proximal tibia before surgery. Mean preoperative varus on standing films was 22° (range, 10°-36°). Because of the patients’ size, we used standing long-leg radiographs, on individual cassettes, for each leg.

Surgical Technique

Before surgery, we use paper cutouts to template the osteotomy wedge. We also use perioperative antibiotics and a standard time-out. For visualization of the entire leg for accurate correction, we prepare and drape the entire leg. A sterile tourniquet is used. At the midshaft of the fibula, a 4-cm incision is made, and dissection is carefully carried down to the fibula. Subperiosteal dissection is performed about the fibula, allowing adequate clearance for an oblique osteotomy. The osteotomy removes about 1 cm of fibula, which is to be used as bone graft for the tibial osteotomy. In addition, a lateral compartment fasciotomy is performed to prevent swelling-related complications. The wound is irrigated and injected with bupivacaine and closed in routine fashion.

We then make an inverted hockey-stick incision over the proximal tibia, centered down to the tibial tubercle. After dissecting down to the anterior compartment, we perform a fasciotomy of about 8 cm to accommodate swelling. Subperiosteal dissection is then performed around the proximal tibia. The medial soft tissues are left attached to increase blood supply and healing. During subperiosteal dissection, soft elevators are used to gently retract the lateral soft tissues along with the inferior and posterior structures. We use fluoroscopic imaging to guide the osteotomy as well as screw and plate placement. We use a 6-hole, 4.5-mm compression plate and screws for fixation. The 2 proximal screws of the plate are predrilled in place to allow for application of the plate after completion of the osteotomy. The plate is then rotated out of position on 1 screw, and the osteotomy is identified under fluoroscopy with the appropriate position distal to the second hole of the 6-hole plate.

An oscillating saw and osteotomes are used to perform the oblique osteotomy. The pre-estimated bone wedge is removed. Wedge size is adjusted, if needed. The bone wedge is morselized for bone graft. The osteotomy is then closed, correcting both varus and internal tibial torsion. Our goal is 5° valgus. After correction is obtained, the plate is placed, and the proximal screw is snugly seated. Three cortical screws are placed distally to hold the plate in place under compression mode, and a cancellous screw is placed superiorly at the proximal portion of the plate for additional fixation. The screw placed proximal to the osteotomy site is a fully threaded cortical screw with excellent compression. Correction and proper placement of hardware are verified with fluoroscopy.

The wound is irrigated and injected with bupivacaine. Bone graft is then placed at the osteotomy site. Additional bone graft is placed posteriorly between the osteotomy site and the muscle mass to stimulate additional healing. Another screw is placed obliquely from the medial side across the osteotomy site to provide additional fixation (Figure 1).

Copyright belongs to the authors

A deep drain is placed and connected to bulb suction for 24 hours after surgery. The wound is then closed in routine fashion. In 2 patients who weighed more than 250 pounds, we used an external fixator for additional stability (Figure 2).

Copyright belongs to the authors

Postoperative Care

The incisions are dressed with antibiotic ointment and 4×4-in bandages and then wrapped with sterile cotton under-cast padding. The leg is placed into a well-padded cylinder cast with the knee flexed 10°. The leg is aligned to about 5° valgus. The cast is then split on the side and spread to allow for swelling and to prevent compartment syndrome.⁵ We also use a drain hooked to bulb suction, which is removed 24 hours after surgery. Toe-touch weight-bearing with crutches is allowed immediately after surgery. The cast is removed at 6 weeks, and a hinged range-of-motion knee brace is worn for another 6 weeks. All patients are allowed to resume normal activity after 4 months. In our 2 external-fixator cases, a cast was not used, and toe-touch weight-bearing and knee motion were allowed immediately. The external fixators were removed at about 10 weeks.

Results

Mean postoperative mechanical femoral-tibial angle was 3°, and mean correction was 26° (range, 16°-43°) (Table). Lateral distal femoral angle did not show significant femoral deformity in our sample. Mean medial proximal tibial angle was 74° (range, 63°-79°). In each case, the varus deformity was primarily in the tibia. Mean tourniquet time was 88 minutes (range, 50-119 min). Our complication rate was 11% (1 knee). In our first case, in which we did not use an extra medial screw, the 4.5-mm plate fractured at the osteotomy site 2.5 months after surgery. The 250-pound patient subsequently lost 17° of correction, and valgus alignment was not achieved. Preoperative varus was 25°, and postoperative alignment was 8° varus. This plate fracture led us to use an extra medial screw for additional stability in all subsequent cases and to consider using an external fixator for patients weighing more than 250 pounds. After the first case, there were no other plate fractures. A potential problem with closing wedge osteotomy is shortening, but varus correction restores some length. Mean postoperative leg-length difference was 10 mm (range, 0-16 mm). No patient complained of leg-length difference during the postoperative follow-up.

Eight and a half months after surgery, 1 patient had hardware removed, at the family’s request. No patient experienced perioperative infection or neurovascular damage. Our overall patient population was obese—mean BMI was 38 (range, 25-48), and mean postoperative weight was 219 pounds. Three of our 8 patients were overweight (BMI, 25-30), and 5 were obese (BMI, >30). For prevention of plate failure, we recommend using an extra oblique screw in all patients and considering an external fixator for patients who weigh more than 250 pounds.

Discussion

Correction of adolescent tibia vara can be challenging because of patient obesity. The technique described here—a modification of the technique of Laurencin and colleagues⁴—is practical and reproducible in this population. The goals in performing osteotomy are to correct the deformity, restore joint alignment, preserve leg length, and prevent recurrent deformity and other complications, such as neurovascular injury, nonunion, and infection.^3,6-8 Our technique minimizes the risk for these complications. For example, the fasciotomy provides excellent decompression of the anterior and lateral compartments, minimizing neurovascular ischemia and the risk for compartment syndrome. During cast placement, splitting and spreading reduce the risk for compartment syndrome as well.⁵

Wagner3,9 demonstrated the utility of a closing wedge proximal tibial osteotomy in adults. Laurencin and colleagues4 showed this technique is effective in correcting tibia vara in a pediatric population. However, they did not specify patient weight and used a small semitubular plate for fixation, and some of their patients had infantile Blount disease. We modified the technique in 3 ways. First, we performed a complete osteotomy. Second, because our patients were adolescents and very large, we used a 6-hole, 4.5-mm compression plate and screws. Third, we used an external fixator for increased stability in patients who weighed more than 250 pounds.

The reported technique, using an oblique metaphyseal closing wedge osteotomy with internal fixation in obese patients, is practical, safe, and reliable. This technique is a useful alternative to an external fixator. We used it on 9 knees with tibia vara, and it was completely successful in 8 cases and partially successful in 1 (hardware breakage occurred). An external fixator was used to prevent hardware breakage in 2 patients who weighed more than 250 pounds. This technique is a valuable treatment option for surgical correction, especially in obese patients.

Blount disease (tibia vara) is an angular tibia deformity that includes varus, increased posterior slope, and internal rotation. This deformity was first described in 1922 by Erlacher1 in Germany. In 1937, Walter Blount2 reported on it in the United States. It is the most common cause of pathologic genu varum in adolescence and childhood.

An oblique incomplete closing wedge osteotomy of the proximal tibial metaphysis was described by Wagner³ for the treatment of unicompartmental osteoarthrosis of the knee in adults. Laurencin and colleagues⁴ applied this technique to the treatment of pediatric tibia vara with favorable results. They spared the medial cortex of the tibia in their incomplete closing wedge osteotomy technique. In each of the 9 cases we treated and describe here, we accidentally completed the tibial osteotomy when attempting the Laurencin technique. Given that the osteotomy was completed, we modified the Laurencin technique by using a 6-hole, 4.5-mm compression plate rather than a 5-hole semitubular plate, and added a large oblique screw from the medial side to compress the osteotomy site and to protect the plate from fracture. In addition, in 2 patients who weighed more than 250 pounds, we used an external fixator for additional stability. In this article, we report the outcomes of correcting adolescent tibia vara with a complete closing wedge tibial osteotomy and an oblique fibular osteotomy.

Materials and Methods

This study was approved by the Institutional Review Board at Pennsylvania State University. Between 2009 and 2012, we performed 9 complete oblique proximal tibial lateral closing wedge osteotomies on 8 patients (2 girls, 6 boys). In each case, the primary diagnosis was Blount disease. One patient also had renal dysplasia and was receiving dialysis. Mean age at time of operation was 15 years (range, 13-17 years). Mean preoperative weight was 215 pounds (range, 119-317 lb). Mean weight gain at follow-up was 4.39 pounds (range, –10 to 19 lb). Mean body mass index (BMI) was 38 (range, 25-48) (Table). All patients had varus angulation of the proximal tibia before surgery. Mean preoperative varus on standing films was 22° (range, 10°-36°). Because of the patients’ size, we used standing long-leg radiographs, on individual cassettes, for each leg.

Surgical Technique

Before surgery, we use paper cutouts to template the osteotomy wedge. We also use perioperative antibiotics and a standard time-out. For visualization of the entire leg for accurate correction, we prepare and drape the entire leg. A sterile tourniquet is used. At the midshaft of the fibula, a 4-cm incision is made, and dissection is carefully carried down to the fibula. Subperiosteal dissection is performed about the fibula, allowing adequate clearance for an oblique osteotomy. The osteotomy removes about 1 cm of fibula, which is to be used as bone graft for the tibial osteotomy. In addition, a lateral compartment fasciotomy is performed to prevent swelling-related complications. The wound is irrigated and injected with bupivacaine and closed in routine fashion.

We then make an inverted hockey-stick incision over the proximal tibia, centered down to the tibial tubercle. After dissecting down to the anterior compartment, we perform a fasciotomy of about 8 cm to accommodate swelling. Subperiosteal dissection is then performed around the proximal tibia. The medial soft tissues are left attached to increase blood supply and healing. During subperiosteal dissection, soft elevators are used to gently retract the lateral soft tissues along with the inferior and posterior structures. We use fluoroscopic imaging to guide the osteotomy as well as screw and plate placement. We use a 6-hole, 4.5-mm compression plate and screws for fixation. The 2 proximal screws of the plate are predrilled in place to allow for application of the plate after completion of the osteotomy. The plate is then rotated out of position on 1 screw, and the osteotomy is identified under fluoroscopy with the appropriate position distal to the second hole of the 6-hole plate.

An oscillating saw and osteotomes are used to perform the oblique osteotomy. The pre-estimated bone wedge is removed. Wedge size is adjusted, if needed. The bone wedge is morselized for bone graft. The osteotomy is then closed, correcting both varus and internal tibial torsion. Our goal is 5° valgus. After correction is obtained, the plate is placed, and the proximal screw is snugly seated. Three cortical screws are placed distally to hold the plate in place under compression mode, and a cancellous screw is placed superiorly at the proximal portion of the plate for additional fixation. The screw placed proximal to the osteotomy site is a fully threaded cortical screw with excellent compression. Correction and proper placement of hardware are verified with fluoroscopy.

The wound is irrigated and injected with bupivacaine. Bone graft is then placed at the osteotomy site. Additional bone graft is placed posteriorly between the osteotomy site and the muscle mass to stimulate additional healing. Another screw is placed obliquely from the medial side across the osteotomy site to provide additional fixation (Figure 1).

Copyright belongs to the authors

A deep drain is placed and connected to bulb suction for 24 hours after surgery. The wound is then closed in routine fashion. In 2 patients who weighed more than 250 pounds, we used an external fixator for additional stability (Figure 2).

Copyright belongs to the authors

Postoperative Care

The incisions are dressed with antibiotic ointment and 4×4-in bandages and then wrapped with sterile cotton under-cast padding. The leg is placed into a well-padded cylinder cast with the knee flexed 10°. The leg is aligned to about 5° valgus. The cast is then split on the side and spread to allow for swelling and to prevent compartment syndrome.⁵ We also use a drain hooked to bulb suction, which is removed 24 hours after surgery. Toe-touch weight-bearing with crutches is allowed immediately after surgery. The cast is removed at 6 weeks, and a hinged range-of-motion knee brace is worn for another 6 weeks. All patients are allowed to resume normal activity after 4 months. In our 2 external-fixator cases, a cast was not used, and toe-touch weight-bearing and knee motion were allowed immediately. The external fixators were removed at about 10 weeks.

Results

Mean postoperative mechanical femoral-tibial angle was 3°, and mean correction was 26° (range, 16°-43°) (Table). Lateral distal femoral angle did not show significant femoral deformity in our sample. Mean medial proximal tibial angle was 74° (range, 63°-79°). In each case, the varus deformity was primarily in the tibia. Mean tourniquet time was 88 minutes (range, 50-119 min). Our complication rate was 11% (1 knee). In our first case, in which we did not use an extra medial screw, the 4.5-mm plate fractured at the osteotomy site 2.5 months after surgery. The 250-pound patient subsequently lost 17° of correction, and valgus alignment was not achieved. Preoperative varus was 25°, and postoperative alignment was 8° varus. This plate fracture led us to use an extra medial screw for additional stability in all subsequent cases and to consider using an external fixator for patients weighing more than 250 pounds. After the first case, there were no other plate fractures. A potential problem with closing wedge osteotomy is shortening, but varus correction restores some length. Mean postoperative leg-length difference was 10 mm (range, 0-16 mm). No patient complained of leg-length difference during the postoperative follow-up.

Eight and a half months after surgery, 1 patient had hardware removed, at the family’s request. No patient experienced perioperative infection or neurovascular damage. Our overall patient population was obese—mean BMI was 38 (range, 25-48), and mean postoperative weight was 219 pounds. Three of our 8 patients were overweight (BMI, 25-30), and 5 were obese (BMI, >30). For prevention of plate failure, we recommend using an extra oblique screw in all patients and considering an external fixator for patients who weigh more than 250 pounds.

Discussion

Correction of adolescent tibia vara can be challenging because of patient obesity. The technique described here—a modification of the technique of Laurencin and colleagues⁴—is practical and reproducible in this population. The goals in performing osteotomy are to correct the deformity, restore joint alignment, preserve leg length, and prevent recurrent deformity and other complications, such as neurovascular injury, nonunion, and infection.^3,6-8 Our technique minimizes the risk for these complications. For example, the fasciotomy provides excellent decompression of the anterior and lateral compartments, minimizing neurovascular ischemia and the risk for compartment syndrome. During cast placement, splitting and spreading reduce the risk for compartment syndrome as well.⁵

Wagner3,9 demonstrated the utility of a closing wedge proximal tibial osteotomy in adults. Laurencin and colleagues4 showed this technique is effective in correcting tibia vara in a pediatric population. However, they did not specify patient weight and used a small semitubular plate for fixation, and some of their patients had infantile Blount disease. We modified the technique in 3 ways. First, we performed a complete osteotomy. Second, because our patients were adolescents and very large, we used a 6-hole, 4.5-mm compression plate and screws. Third, we used an external fixator for increased stability in patients who weighed more than 250 pounds.

The reported technique, using an oblique metaphyseal closing wedge osteotomy with internal fixation in obese patients, is practical, safe, and reliable. This technique is a useful alternative to an external fixator. We used it on 9 knees with tibia vara, and it was completely successful in 8 cases and partially successful in 1 (hardware breakage occurred). An external fixator was used to prevent hardware breakage in 2 patients who weighed more than 250 pounds. This technique is a valuable treatment option for surgical correction, especially in obese patients.

SAN DIEGO – Among patients undergoing elective surgical spine procedures, the Short Form–6D derived from the Neck Disability Index was more valid and a better responsive measure of general health and quality of life, compared with the Short Form–6D derived from the Short Form–12 or the EuroQol-5D, results from a single-center study showed.

For such quality of life measures to be useful and meaningful, they “should be reproducible, responsive, economical, easy to use, and sensitive to responder burden,” Dr. John A. Sielatycki said at the annual meeting of the Cervical Spine Research Society.

“The EQ-5D is well established and commonly used in many of these studies, as is SF-6D, which in some cases has been shown to be more sensitive in certain disease states,” explained Dr. Sielatycki, a resident in the department of orthopedics at Vanderbilt University, Nashville, Tenn. “The differences between SF-6D and EQ-5D have been studied in a wide variety of disease conditions, but to our knowledge few have looked at this specifically in the setting of cervical spine operations.”

To analyze the validity and responsiveness of the SF-6D (derived from both the SF-12 and the NDI) and the EQ-5D in determining overall health and quality of life following elective cervical spine procedures, Dr. Sielatycki and his associates compared the three tools in 420 consecutive patients who presented over the course of 2 years. Trauma and workers’ compensation cases were excluded from the study, as were patients who had a tumor or an infection.

The researchers collected outcome measures at baseline, 3 months, 6 months, 12 months, and yearly thereafter, and defined meaningful improvement as having a North American Spine Society patient satisfaction score of 1, indicating the procedure “met the patient’s expectations.” Next, they generated receiver operating characteristic curves to discriminate between meaningful and nonmeaningful improvement.

The SF-6D (NDI) was a more valid discriminator of meaningful improvement, compared with the SF-6D (SF-12) or the EQ-5D (area under the curve of .69, .65, and .62, respectively). It was also a more responsive measure, compared with the SF-6D (SF-12) and the EQ-5D (standardized response means difference of .66, .48, and .44, respectively).

“Surgeons, outcomes researchers, and payers should use health metrics that are most responsive to changes in the particular disease in question,” Dr. Sielatycki said. “Based on this analysis, SF-6D derived from NDI may be a more valid and responsive measure of improvement in patients undergoing cervical procedures. We suggest that this metric be used in cost-effectiveness analysis and in calculating quality-adjusted life years for cervical spine patients.”

Dr. Sielatycki acknowledged certain limitations of the study, including the fact that it “should have some external validation done to further corroborate our findings. Our gold standard of meaningful improvement has not been established.”

Dr. Sielatycki reported having no financial disclosures.

[email protected]

SAN DIEGO – Among patients undergoing elective surgical spine procedures, the Short Form–6D derived from the Neck Disability Index was more valid and a better responsive measure of general health and quality of life, compared with the Short Form–6D derived from the Short Form–12 or the EuroQol-5D, results from a single-center study showed.

For such quality of life measures to be useful and meaningful, they “should be reproducible, responsive, economical, easy to use, and sensitive to responder burden,” Dr. John A. Sielatycki said at the annual meeting of the Cervical Spine Research Society.

“The EQ-5D is well established and commonly used in many of these studies, as is SF-6D, which in some cases has been shown to be more sensitive in certain disease states,” explained Dr. Sielatycki, a resident in the department of orthopedics at Vanderbilt University, Nashville, Tenn. “The differences between SF-6D and EQ-5D have been studied in a wide variety of disease conditions, but to our knowledge few have looked at this specifically in the setting of cervical spine operations.”

To analyze the validity and responsiveness of the SF-6D (derived from both the SF-12 and the NDI) and the EQ-5D in determining overall health and quality of life following elective cervical spine procedures, Dr. Sielatycki and his associates compared the three tools in 420 consecutive patients who presented over the course of 2 years. Trauma and workers’ compensation cases were excluded from the study, as were patients who had a tumor or an infection.

The researchers collected outcome measures at baseline, 3 months, 6 months, 12 months, and yearly thereafter, and defined meaningful improvement as having a North American Spine Society patient satisfaction score of 1, indicating the procedure “met the patient’s expectations.” Next, they generated receiver operating characteristic curves to discriminate between meaningful and nonmeaningful improvement.

The SF-6D (NDI) was a more valid discriminator of meaningful improvement, compared with the SF-6D (SF-12) or the EQ-5D (area under the curve of .69, .65, and .62, respectively). It was also a more responsive measure, compared with the SF-6D (SF-12) and the EQ-5D (standardized response means difference of .66, .48, and .44, respectively).

“Surgeons, outcomes researchers, and payers should use health metrics that are most responsive to changes in the particular disease in question,” Dr. Sielatycki said. “Based on this analysis, SF-6D derived from NDI may be a more valid and responsive measure of improvement in patients undergoing cervical procedures. We suggest that this metric be used in cost-effectiveness analysis and in calculating quality-adjusted life years for cervical spine patients.”

Dr. Sielatycki acknowledged certain limitations of the study, including the fact that it “should have some external validation done to further corroborate our findings. Our gold standard of meaningful improvement has not been established.”

Dr. Sielatycki reported having no financial disclosures.

[email protected]

SAN DIEGO – Among patients undergoing elective surgical spine procedures, the Short Form–6D derived from the Neck Disability Index was more valid and a better responsive measure of general health and quality of life, compared with the Short Form–6D derived from the Short Form–12 or the EuroQol-5D, results from a single-center study showed.

For such quality of life measures to be useful and meaningful, they “should be reproducible, responsive, economical, easy to use, and sensitive to responder burden,” Dr. John A. Sielatycki said at the annual meeting of the Cervical Spine Research Society.

“The EQ-5D is well established and commonly used in many of these studies, as is SF-6D, which in some cases has been shown to be more sensitive in certain disease states,” explained Dr. Sielatycki, a resident in the department of orthopedics at Vanderbilt University, Nashville, Tenn. “The differences between SF-6D and EQ-5D have been studied in a wide variety of disease conditions, but to our knowledge few have looked at this specifically in the setting of cervical spine operations.”

To analyze the validity and responsiveness of the SF-6D (derived from both the SF-12 and the NDI) and the EQ-5D in determining overall health and quality of life following elective cervical spine procedures, Dr. Sielatycki and his associates compared the three tools in 420 consecutive patients who presented over the course of 2 years. Trauma and workers’ compensation cases were excluded from the study, as were patients who had a tumor or an infection.

The researchers collected outcome measures at baseline, 3 months, 6 months, 12 months, and yearly thereafter, and defined meaningful improvement as having a North American Spine Society patient satisfaction score of 1, indicating the procedure “met the patient’s expectations.” Next, they generated receiver operating characteristic curves to discriminate between meaningful and nonmeaningful improvement.

The SF-6D (NDI) was a more valid discriminator of meaningful improvement, compared with the SF-6D (SF-12) or the EQ-5D (area under the curve of .69, .65, and .62, respectively). It was also a more responsive measure, compared with the SF-6D (SF-12) and the EQ-5D (standardized response means difference of .66, .48, and .44, respectively).

“Surgeons, outcomes researchers, and payers should use health metrics that are most responsive to changes in the particular disease in question,” Dr. Sielatycki said. “Based on this analysis, SF-6D derived from NDI may be a more valid and responsive measure of improvement in patients undergoing cervical procedures. We suggest that this metric be used in cost-effectiveness analysis and in calculating quality-adjusted life years for cervical spine patients.”

Dr. Sielatycki acknowledged certain limitations of the study, including the fact that it “should have some external validation done to further corroborate our findings. Our gold standard of meaningful improvement has not been established.”

Dr. Sielatycki reported having no financial disclosures.

[email protected]

Recording the temperature of skin over an inflamed joint may identify rheumatoid arthritis patients at high risk of joint damage, an exploratory study suggested.

Dermal joint temperature could become a screening test to “quickly and accurately” identify individual RA patients at high risk for radiographic damage and those who may benefit from biologic therapy, said Dr. Maria Greenwald, a rheumatologist in group practice in Palm Desert, Calif., and her colleagues.

Fuse/ThinkStock

During 2009-2014, the investigators enrolled seropositive RA patients who were on stable doses of methotrexate (20-25 mg/wk) for the past 3 months and did not use biologics or other disease-modifying antirheumatic drugs. It took 9 months to enroll 104 patients with cool joints and 42 months to enroll 104 patients with hot joints, suggesting “that at a single office visit, RA patients on methotrexate are five times more likely to have cool joints than hot joints,” the researchers reported.

The results showed that patients in the hot-joint cohort had a nearly fourfold higher risk of x-ray damage at 1-year follow-up, compared with those with cool joints (change in modified van der Heijde total Sharp score [mTSS]: 8.7 vs. 2.5; P less than .001). Patients with hot joints had an average joint temperature exceeding central forehead body temperature by 1.1° F, whereas those with cool joints had an average joint temperature of 4.3° F below central forehead body temperature.

In the cohort of patients with hot joints, 74% had clear x-ray evidence of new joint damage (mTSS of 5 or greater), compared with 7% of cold-joint cohort patients at 1-year follow-up. Joint temperature at the hand or wrist predicted x-ray damage in the next year with 92% sensitivity and 78% specificity(Arthritis Care Res. 2015 Dec 14. doi: 10.1002/acr.22813).

Patients in the hot-joint cohort were younger, had more recent onset of RA, and had a significantly higher Westergren erythrocyte sedimentation rate than patients in the cool-joint cohort, the investigators noted.

They suggested a future study might define a hot-joint cohort as RA patients with a joint that measures over a set point such as 98° F. “Such a cutoff would make assessment very simple and would maintain the specificity and sensitivity of the model,” they said.

No conflicts of interest were disclosed.

Recording the temperature of skin over an inflamed joint may identify rheumatoid arthritis patients at high risk of joint damage, an exploratory study suggested.

Dermal joint temperature could become a screening test to “quickly and accurately” identify individual RA patients at high risk for radiographic damage and those who may benefit from biologic therapy, said Dr. Maria Greenwald, a rheumatologist in group practice in Palm Desert, Calif., and her colleagues.

Fuse/ThinkStock

During 2009-2014, the investigators enrolled seropositive RA patients who were on stable doses of methotrexate (20-25 mg/wk) for the past 3 months and did not use biologics or other disease-modifying antirheumatic drugs. It took 9 months to enroll 104 patients with cool joints and 42 months to enroll 104 patients with hot joints, suggesting “that at a single office visit, RA patients on methotrexate are five times more likely to have cool joints than hot joints,” the researchers reported.

The results showed that patients in the hot-joint cohort had a nearly fourfold higher risk of x-ray damage at 1-year follow-up, compared with those with cool joints (change in modified van der Heijde total Sharp score [mTSS]: 8.7 vs. 2.5; P less than .001). Patients with hot joints had an average joint temperature exceeding central forehead body temperature by 1.1° F, whereas those with cool joints had an average joint temperature of 4.3° F below central forehead body temperature.

In the cohort of patients with hot joints, 74% had clear x-ray evidence of new joint damage (mTSS of 5 or greater), compared with 7% of cold-joint cohort patients at 1-year follow-up. Joint temperature at the hand or wrist predicted x-ray damage in the next year with 92% sensitivity and 78% specificity(Arthritis Care Res. 2015 Dec 14. doi: 10.1002/acr.22813).

Patients in the hot-joint cohort were younger, had more recent onset of RA, and had a significantly higher Westergren erythrocyte sedimentation rate than patients in the cool-joint cohort, the investigators noted.

They suggested a future study might define a hot-joint cohort as RA patients with a joint that measures over a set point such as 98° F. “Such a cutoff would make assessment very simple and would maintain the specificity and sensitivity of the model,” they said.

No conflicts of interest were disclosed.

Recording the temperature of skin over an inflamed joint may identify rheumatoid arthritis patients at high risk of joint damage, an exploratory study suggested.

Dermal joint temperature could become a screening test to “quickly and accurately” identify individual RA patients at high risk for radiographic damage and those who may benefit from biologic therapy, said Dr. Maria Greenwald, a rheumatologist in group practice in Palm Desert, Calif., and her colleagues.

Fuse/ThinkStock

During 2009-2014, the investigators enrolled seropositive RA patients who were on stable doses of methotrexate (20-25 mg/wk) for the past 3 months and did not use biologics or other disease-modifying antirheumatic drugs. It took 9 months to enroll 104 patients with cool joints and 42 months to enroll 104 patients with hot joints, suggesting “that at a single office visit, RA patients on methotrexate are five times more likely to have cool joints than hot joints,” the researchers reported.

The results showed that patients in the hot-joint cohort had a nearly fourfold higher risk of x-ray damage at 1-year follow-up, compared with those with cool joints (change in modified van der Heijde total Sharp score [mTSS]: 8.7 vs. 2.5; P less than .001). Patients with hot joints had an average joint temperature exceeding central forehead body temperature by 1.1° F, whereas those with cool joints had an average joint temperature of 4.3° F below central forehead body temperature.

In the cohort of patients with hot joints, 74% had clear x-ray evidence of new joint damage (mTSS of 5 or greater), compared with 7% of cold-joint cohort patients at 1-year follow-up. Joint temperature at the hand or wrist predicted x-ray damage in the next year with 92% sensitivity and 78% specificity(Arthritis Care Res. 2015 Dec 14. doi: 10.1002/acr.22813).

Patients in the hot-joint cohort were younger, had more recent onset of RA, and had a significantly higher Westergren erythrocyte sedimentation rate than patients in the cool-joint cohort, the investigators noted.

They suggested a future study might define a hot-joint cohort as RA patients with a joint that measures over a set point such as 98° F. “Such a cutoff would make assessment very simple and would maintain the specificity and sensitivity of the model,” they said.

No conflicts of interest were disclosed.

Women with knee osteoarthritis who had low thigh muscle strength were more likely to need a knee replacement in a case-control study of participants in the Osteoarthritis Initiative (OAI).

In particular, predictors of knee replacement included knee extensor weakness in the year prior to knee replacement and longitudinal deterioration in knee extensor strength over a 2-year observation period prior to surgery. Measurement of knee extensor strength in women with knee osteoarthritis may then indicate who could benefit from weight training exercises to potentially delay or prevent the need for knee replacement surgery, said the researchers, led by Dr. Adam Culvenor of Paracelsus Medical University in Salzburg, Austria (Arthritis Rheumatol. 2015 Dec 14. doi: 10.1002/art.39540).

The optimal knee extensor strength threshold for differentiating those with and without knee replacement risk was approximately 200 N or 0.9 Nm/kg; or prevention of any loss of knee extensor strength over 2 years.

©pixologicstudio/thinkstockphotos.com

“There appears to be a considerable window for women below this threshold to obtain realistic strength gains and potentially lower the risk of knee replacement,” the study authors concluded.

In the multicenter, longitudinal, case-control study of 4,796 participants in the OAI (60% of whom were women), the investigators identified 136 participants who had received a knee replacement and matched them with controls who had not received a knee replacement and were similar in age, body mass index (BMI), and radiographic stage. The mean age of the women was 65 years and the mean BMI was 29 kg/m².

The results showed that knee extensor strength at the examination prior to knee replacement (time T₀), which occurred 2 years or less before surgery, was significantly lower in females who had received a knee replacement than in matched controls (pain-adjusted odds ratio, 1.72; 95% confidence interval, 1.16-2.56; P = .007). Measurement of the longitudinal change in knee extensor and flexor strength between T₀ and 2 years prior to T₀ (T_-2) also provided similar results (pain-adjusted OR, 4.30; 95% CI, 1.34-13.79; P = .014). The findings were independent of age, BMI, and radiographic disease severity, the researchers noted.

The investigators found no relationship between knee extensor or flexor muscle strength in men and subsequent need for knee replacement surgery. The relationship between thigh muscle strength and knee replacement for women did not extend to measurements made at T_-2 or T_-4 or the change in thigh muscle strength between T_-2 and T_-4.

The OAI receives funding from the National Institutes of Health, Merck Research Laboratories, Novartis, GlaxoSmithKline, and Pfizer. The work was also funded by a grant from the European Union Seventh Framework Programme. One author disclosed consulting or preparing educational sessions for pharmaceutical companies and for receiving research support. Two authors reported being employees of Chondrometrics GmbH, a company providing MR image analysis services to academic researchers and to industry.

Women with knee osteoarthritis who had low thigh muscle strength were more likely to need a knee replacement in a case-control study of participants in the Osteoarthritis Initiative (OAI).

In particular, predictors of knee replacement included knee extensor weakness in the year prior to knee replacement and longitudinal deterioration in knee extensor strength over a 2-year observation period prior to surgery. Measurement of knee extensor strength in women with knee osteoarthritis may then indicate who could benefit from weight training exercises to potentially delay or prevent the need for knee replacement surgery, said the researchers, led by Dr. Adam Culvenor of Paracelsus Medical University in Salzburg, Austria (Arthritis Rheumatol. 2015 Dec 14. doi: 10.1002/art.39540).

The optimal knee extensor strength threshold for differentiating those with and without knee replacement risk was approximately 200 N or 0.9 Nm/kg; or prevention of any loss of knee extensor strength over 2 years.

©pixologicstudio/thinkstockphotos.com

“There appears to be a considerable window for women below this threshold to obtain realistic strength gains and potentially lower the risk of knee replacement,” the study authors concluded.

In the multicenter, longitudinal, case-control study of 4,796 participants in the OAI (60% of whom were women), the investigators identified 136 participants who had received a knee replacement and matched them with controls who had not received a knee replacement and were similar in age, body mass index (BMI), and radiographic stage. The mean age of the women was 65 years and the mean BMI was 29 kg/m².

The results showed that knee extensor strength at the examination prior to knee replacement (time T₀), which occurred 2 years or less before surgery, was significantly lower in females who had received a knee replacement than in matched controls (pain-adjusted odds ratio, 1.72; 95% confidence interval, 1.16-2.56; P = .007). Measurement of the longitudinal change in knee extensor and flexor strength between T₀ and 2 years prior to T₀ (T_-2) also provided similar results (pain-adjusted OR, 4.30; 95% CI, 1.34-13.79; P = .014). The findings were independent of age, BMI, and radiographic disease severity, the researchers noted.

The investigators found no relationship between knee extensor or flexor muscle strength in men and subsequent need for knee replacement surgery. The relationship between thigh muscle strength and knee replacement for women did not extend to measurements made at T_-2 or T_-4 or the change in thigh muscle strength between T_-2 and T_-4.

The OAI receives funding from the National Institutes of Health, Merck Research Laboratories, Novartis, GlaxoSmithKline, and Pfizer. The work was also funded by a grant from the European Union Seventh Framework Programme. One author disclosed consulting or preparing educational sessions for pharmaceutical companies and for receiving research support. Two authors reported being employees of Chondrometrics GmbH, a company providing MR image analysis services to academic researchers and to industry.

Women with knee osteoarthritis who had low thigh muscle strength were more likely to need a knee replacement in a case-control study of participants in the Osteoarthritis Initiative (OAI).

In particular, predictors of knee replacement included knee extensor weakness in the year prior to knee replacement and longitudinal deterioration in knee extensor strength over a 2-year observation period prior to surgery. Measurement of knee extensor strength in women with knee osteoarthritis may then indicate who could benefit from weight training exercises to potentially delay or prevent the need for knee replacement surgery, said the researchers, led by Dr. Adam Culvenor of Paracelsus Medical University in Salzburg, Austria (Arthritis Rheumatol. 2015 Dec 14. doi: 10.1002/art.39540).

The optimal knee extensor strength threshold for differentiating those with and without knee replacement risk was approximately 200 N or 0.9 Nm/kg; or prevention of any loss of knee extensor strength over 2 years.

©pixologicstudio/thinkstockphotos.com

“There appears to be a considerable window for women below this threshold to obtain realistic strength gains and potentially lower the risk of knee replacement,” the study authors concluded.

In the multicenter, longitudinal, case-control study of 4,796 participants in the OAI (60% of whom were women), the investigators identified 136 participants who had received a knee replacement and matched them with controls who had not received a knee replacement and were similar in age, body mass index (BMI), and radiographic stage. The mean age of the women was 65 years and the mean BMI was 29 kg/m².

The results showed that knee extensor strength at the examination prior to knee replacement (time T₀), which occurred 2 years or less before surgery, was significantly lower in females who had received a knee replacement than in matched controls (pain-adjusted odds ratio, 1.72; 95% confidence interval, 1.16-2.56; P = .007). Measurement of the longitudinal change in knee extensor and flexor strength between T₀ and 2 years prior to T₀ (T_-2) also provided similar results (pain-adjusted OR, 4.30; 95% CI, 1.34-13.79; P = .014). The findings were independent of age, BMI, and radiographic disease severity, the researchers noted.

The investigators found no relationship between knee extensor or flexor muscle strength in men and subsequent need for knee replacement surgery. The relationship between thigh muscle strength and knee replacement for women did not extend to measurements made at T_-2 or T_-4 or the change in thigh muscle strength between T_-2 and T_-4.

The OAI receives funding from the National Institutes of Health, Merck Research Laboratories, Novartis, GlaxoSmithKline, and Pfizer. The work was also funded by a grant from the European Union Seventh Framework Programme. One author disclosed consulting or preparing educational sessions for pharmaceutical companies and for receiving research support. Two authors reported being employees of Chondrometrics GmbH, a company providing MR image analysis services to academic researchers and to industry.