Anterior physeal separation. A sign indicating a high risk for avascular necrosis after slipped capital femoral epiphysis

[Slipped capital femoral epiphysis]

BACKGROUND

In slipped capital femoral epiphysis (SCFE), the femoral head slides in an anterosuperior direction along the growth plate. The femoral head remains in the acetabulum. The pathogenesis of SCFE is multifactorial. An important predisposing factor is obesity.

PROBLEM

Epiphysiolysis can compromise the blood supply to the epiphysis and osteonecrosis of the femoral head may result.

DIAGNOSTICS AND PROGNOSIS

Conventional radiography represents the first diagnostic step. The long-term prognosis of the disease depends on the residual deformity of the femoral head and in the worst case may result in early osteoarthritis of the hip joint.

Temporal changes in slipped upper femoral epiphysis at a regional level: a declining incidence and literature review

PURPOSE

Slipped upper femoral epiphysis (SUFE) is one of the most common adolescent hip pathologies in children with potential for life-long morbidity secondary to avascular necrosis (AVN). The primary aim is to determine an up-to-date demographic of SUFE, as well as current trends in presentation and radiological characteristics. Secondary aims are to quantify prophylactic fixation and subsequent contralateral SUFE.

METHODS

Between 01 January 2013 and 31 December 2015, all cases of SUFE were identified in Northern Ireland. Patient demographics, slip characteristics and outcomes are presented and the incidence rates were calculated using census data. Temporal changes in incidence, compared with a previous cohort, are demonstrated.

RESULTS

A total of 56 patients (80 hips) were identified. Based on census data, SUFE incidence has declined from 7.14 to 4.69/100,000 population aged < 16 years. Male cases predominated by > 2:1 ratio, and tended to be older than female cases. Approximately 75% of patients were above the 75th centile for age-sex adjusted body weight. Knee pain as a presenting symptom led to a delay in diagnosis. Prophylactic fixation was performed in 25.9%, with contralateral slips occurring in 27.5%. AVN occurred in 7.4% and remained static.

CONCLUSION

The incidence of SUFE has declined ~34% in our region. When SUFE occurs, knee pain often results in a delay in definitive diagnosis, and commands clinical vigilance to avoid delays in diagnosis. Patients in our region should be aware of a 1-in-4 contralateral slip rate. Overall, AVN rates remain static and are acceptable, despite the declining incidence of SUFE.

LEVEL OF EVIDENCE

Level III - Retrospective Cohort Study.

Is the femoral head dead or alive before surgery of slipped capital femoral epiphysis? Interest of perfusion Magnetic Resonance Imaging

BACKGROUND

The most common complication of slipped capital femoral epiphysis (SCFE) is avascular necrosis (AVN) of the femoral head. Surgical treatments including reduction of the femoral head are considered as a risk factor for avascular necrosis. The purpose of this study was to investigate the role of perfusion Magnetic Resonance Imaging (MRI) into the surgical decision-making sequence.

METHODS

Eighteen children with 19 slipped capital femoral epiphysis were retrospectively included. SFCE was unstable in nine cases and stable in ten cases. The slip angle was higher than 60° in 14 cases. Perfusion MRI with dynamic gadolinium-enhanced subtraction sequences were done in all the cases before and after surgical treatment.

RESULTS

On nineteen hips, eight were devascularized before surgery. All were unstable. After surgery, six on eight had a complete revascularization, one had a focal necrosis and one remained devascularized. A postoperative devascularization with normal preoperative MRI was noted once. On nineteen hips, a total of three avascular necrosis occurred.

CONCLUSION

Perfusion MRI is useful to assess preoperative and postoperative vascular status in SFCE. Preoperative devascularization could improve or stay equal after surgical treatment. Persistent devascularization could be responsible for avascular necrosis of the femoral head.

Slipped capital femoral epiphysis: relevant pathophysiological findings with open surgery

BACKGROUND

Traditionally arthrotomy has rarely been performed during surgery for slipped capital femoral epiphysis (SCFE). As a result, most pathophysiological information about the articular surfaces was derived clinically and radiographically. Novel insights regarding deformity-induced damage and epiphyseal perfusion became available with surgical hip dislocation.

QUESTIONS/PURPOSES

We (1) determined the influence of chronicity of prodromal symptoms and severity of SCFE deformity on severity of cartilage damage. (2) In surgically confirmed disconnected epiphyses, we determined the influence of injury and time to surgery on epiphyseal perfusion; and (3) the frequency of new bone at the posterior neck potentially reducing perfusion during epimetaphyseal reduction.

METHODS

We reviewed 116 patients with 119 SCFE and available records treated between 1996 and 2011. Acetabular cartilage damage was graded as +/++/+++ in 109 of the 119 hips. Epiphyseal perfusion was determined with laser-Doppler flowmetry at capsulotomy and after reduction. Information about bone at the posterior neck was retrieved from operative reports.

RESULTS

Ninety-seven of 109 hips (89%) had documented cartilage damage; severity was not associated with higher slip angle or chronicity; disconnected epiphyses had less damage. Temporary or definitive cessation of perfusion in disconnected epiphyses increased with time to surgery; posterior bone resection improved the perfusion. In one necrosis, the retinaculum was ruptured; two were in the group with the longest time interval. Posterior bone formation is frequent in disconnected epiphyses, even without prodromal periods.

CONCLUSIONS

Addressing the cause of cartilage damage (cam impingement) should become an integral part of SCFE surgery. Early surgery for disconnected epiphyses appears to reduce the risk of necrosis. Slip reduction without resection of posterior bone apposition may jeopardize epiphyseal perfusion.

LEVEL OF EVIDENCE

Level IV, retrospective case series. See Guidelines for Authors for a complete description of levels of evidence.

Clinical stability of slipped capital femoral epiphysis does not correlate with intraoperative stability

BACKGROUND

The most important objective of clinical classifications of slipped capital femoral epiphysis (SCFE) is to identify hips associated with a high risk of avascular necrosis (AVN)--so-called unstable or acute slips; however, closed surgery makes confirmation of physeal stability difficult. Performing the capital realignment procedure in SCFE treatment we observed that clinical estimation of physeal stability did not always correlate with intraoperative findings at open surgery. This motivated us to perform a systematic comparison of the clinical classification systems with the intraoperative observations.

QUESTIONS/PURPOSES

We asked: (1) Is the classification of an acute versus chronic slip based on the duration of symptoms sensitive and specific in detecting intraoperative disrupted physes in patients with SCFE? (2) Is the stable/unstable classification system based on clinical symptoms sensitive and specific in detecting intraoperative disrupted physes in patients with SCFE?

METHODS

We retrospectively reviewed 82 patients with SCFE treated by open surgery between 1996 and 2009. We classified the clinical stability of all hips using the classifications based on onset of symptoms and on function. We classified intraoperative stability as intact or disrupted. We determined the sensitivity and specificity of two classification systems to determine intraoperative stability.

RESULTS

Complete physeal disruption at open surgery was seen in 28 of the 82 hips (34%). With classification as acute, acute-on-chronic, and chronic, the sensitivity for disrupted physes was 82% and the specificity was 44%. With the classification of Loder et al., the values were 39% and 76%, respectively.

CONCLUSION

Current clinical classification systems are limited in accurately diagnosing the physeal stability in SCFE.

LEVEL OF EVIDENCE

Level III, retrospective diagnostic study. See Guidelines for Authors for a complete description of levels of evidence.

Open reduction and internal fixation of unstable slipped capital femoral epiphysis by means of surgical dislocation does not decrease the rate of avascular necrosis: a preliminary study

PURPOSE

The treatment of unstable slipped capital femoral epiphysis (SCFE) remains controversial. Surgical dislocation and open reduction has the potential to significantly reduce the rate of avascular necrosis (AVN) by allowing direct preservation of the femoral head blood supply. The purpose of this study was to determine if open reduction of the unstable SCFE by means of surgical hip dislocation reduced the risk of AVN compared with closed reduction and percutaneous pinning.

METHODS

We reviewed the medical records and radiographs of patients treated at our institution between the years 2000 and 2008. Sex, age, side of slip, precipitating event, pre- and post-operative anterior physeal separation (APS) and slip angle, slip severity, time between inciting event and surgical treatment, number of screws used, development of AVN, and need for subsequent surgery were evaluated. Statistical analysis was performed to compare risk factors and occurrence of AVN.

RESULTS

From 2004 to 2008, we treated 12 patients with unstable SCFEs: six had closed reduction and percutaneous pinning and six underwent open reduction by means of surgical hip dislocation. There were no statistically significant differences between the two groups regarding sex, age, slip angle, APS, time to surgery, and AVN rate. At follow-up, 4 (66.7 %) patients had AVN in the group which had open reduction, while 2 (33.3 %) patients had AVN in the group which underwent closed reduction. (p = 0.57).

CONCLUSIONS

Open reduction of the unstable SCFE by means of surgical dislocation of the hip does not decrease the rate of AVN when compared to closed reduction.

Prognostic significance of stability in slipped upper femoral epiphysis: a systematic review and meta-analysis

OBJECTIVE

To examine associations of major complications after surgical treatment of slipped upper femoral epiphysis (SUFE) with condition- and treatment-related risk factors.

STUDY DESIGN

This systematic review and meta-analysis of observational studies used an electronic literature search of Embase and Medline supplemented by a manual search of bibliographies. The studies enrolled children and adolescents with SUFE, defined stable and unstable disease, and reported at least 3 primary endpoints: avascular necrosis (AVN), chondrolysis, and reoperation. Random-effects meta-regression analysis was performed when possible.

RESULTS

The weighted risk for AVN, derived from intercept-only meta-regression, was estimated as 5.3% (95% confidence interval [CI], 3.4%-7.2%). Patients with unstable slips had a 9.4-fold greater risk of developing AVN. Instability proved to be an independent predictor for AVN. The weighted risk of chondrolysis was 0.8% (95% CI, 0.2%-1.4%), associated with unstable slips and osteotomies. The risk of reoperation was estimated at 5.5% (95% CI, 1.7%-9.3%). Loss of fixation was the primary reason for reoperation.

CONCLUSIONS

Current evidence indicates that unstable slips are at a significantly higher risk for AVN than stable slips, regardless of the attempted surgical approach. Little clinical information is available regarding chondrolysis and reoperation in relation to the stability of the physis.

The role of pre-treatment MRI in established cases of slipped capital femoral epiphysis

BACKGROUND

Slipped capital femoral epiphysis (SCFE) often results in functional impairment and premature osteoarthritis despite surgical treatment. Treatment decisions are commonly based on the clinical history and radiographic appearance. This study assesses the pre-treatment features of SCFE and correlates them to the clinical history to: (1) define the underlying pathological mechanisms; (2) correlate the morphological hip abnormalities with the clinical classifications; (3) identify specific magnetic resonance imaging (MRI) features that could carry prognostic implications for treatment approach and outcome.

METHODS

Clinical history and pre- and posttreatment radiographs and pre-treatment MRIs of 14 patients with 15 affected hips were reviewed. Alignment, impingement, fulcrum formation, remodelling, osteopenia, synovitis, joint effusion, bone marrow and soft tissue oedema and status of the physis and the periosteal sleeve were assessed and related to the clinical history, in particular history of trauma, duration of clinical symptoms and ability to bear weight.

RESULTS

Bone marrow oedema around the growth plate and joint effusion occurred in all patients. Synovitis occurred in 13/15 patients. 6 patients had a fall before presenting with SCFE. 5/6 had periarticular soft tissue oedema, complete disruption of the physis and partial periosteal sleeve disruption. 9 patients had no fall prior to presentation, physis and periost were intact in 7/9; periarticular oedema was not seen. 14/15 showed evidence of chronic remodelling. Despite an acute clinical history remodelling was present. A fulcrum-like alignment, impingement of the epiphysis on the metaphysis with a small area of physical contact, was seen in 8 patients, 6/8 had a prior fall. There was no case of avascular necrosis. Spontaneous reduction of SCFE occurred in 1 case, the only case without chronic remodelling. With MRI as gold standard radiographs underestimate the severity of SCFE.

CONCLUSION

Synovitis, periphyseal oedema and joint effusion are regular features of SCFE. The clinical history and findings are unreliable for the classification of SCFE. Radiographs underestimate the severity of SCFE. SCFE is often a Salter Harris I injury due to a fall with considerable periarticular soft tissue trauma and a potentially unstable alignment of epi- and metaphysis. This can lead to spontaneous reduction prior to surgery, MRI can potentially identify unstable, reducible slips. If the mode of surgical treatment depends on the particular nature of the SCFE then MRI contributes to surgical decision-making.

LEVEL OF EVIDENCE

Level 4, case series.

[Factors influencing the development of avascular necrosis in non-operative treatment of the acute slipped capital femoral epiphysis]

INTRODUCTION

The acute slipped capital femoral epiphysis can result in development of avascular necrosis of the femoral head which is very difficult condition to treat. Orthopedic surgeon can influence the development of avascular necrosis.

OBJECTIVE

The main objective in our study was to identify factors influencing the development of avascular necrosis in nonoperative treated patients for the acute slipped capital femoral epiphysis.

METHOD

A total of 53 patients and 59 hips treated for the acute slipped capital femoral epiphysis at the Institute for Orthopedic Surgery,Banjica" between 1968-2004 were studied. Necessary data were obtained from the accurate medical records.

RESULTS

Avascular necrosis of the femoral head was diagnosed in 8 patients (13.56%). Six of them (75%) were treated by manipulative reduction in general anesthesia and spica cast immobilization. Fischer test, used for statistical data processing, found significant difference between two non-operative methods of treatment (p = 0.0008).

CONCLUSION

Higher-degree epihyseal displacement as well as complete separation of the physis and metaphysis were found to be the risk factors of avascular necrosis. Every manipulation with the affected hip was also associated with higher percentage of avascular necrosis of the femoral head.

Controversies in slipped capital femoral epiphysis

Slipped capital femoral epiphysis (SCFE) is a common adolescent hip disorder. This article reviews the major controversies in SCFE as of the year 2005. These are (1) treatment of the unstable SCFE, (2) the role of osteotomy in the treatment of SCFE, (3) prophylactic fixation of the contralateral hip in children presenting with unilateral SCFE, and (4) methods of fixation in the very young child with SCFE.

Slipped capital femoral epiphysis in dogs

In a retrospective review of 43 femoral fractures, three dogs had separation of the femoral capital epiphysis from the metaphysis in the absence of trauma. Two of these dogs also had evidence of pathology in the contralateral femoral neck including, in one dog, displacement of the capital epiphysis in relation to the metaphysis without actual separation. The case histories, radiographic features and histopathological findings of these cases were reviewed and compared with previous cases of slipped capital femoral epiphysis (SCFE) reported in dogs and also with SCFE in children. Pre-slip, acute, chronic and acute-on-chronic slips were Identified. Based on the cases reviewed, the authors advise internal fixation of stable slipped epiphyses in dogs. This may also be appropriate for unstable separations, although resorption of the femoral neck may preclude stable fixation and necessitate femoral head and neck excision.