Subcapital Shortening Osteotomy for Severe Slipped Capital Femoral Epiphysis: Preliminary Results of the French Multicenter Study

Modified Dunn Technique for Unstable Slipped Capital Femoral Epiphysis: A Midterm Single Center Experience

Objective  To evaluate the safety and reproducibility of the surgery for unstable slipped capital femoral epiphysis (SCFE) through the modified Dunn technique in a single center cohort from Brazil. Methods  We retrospectively analyzed a cohort of patients submitted to this procedure by a single surgeon who was a hip preservation specialist. Demographic data and radiographic angles were evaluated for the relative risk (RR) of avascular necrosis (AVN) using a log-binomial regression model with simple and random effects. Results  Among the 30 patients (30 hips) with a mean age of 11.79 years at the time of the operation, there were 17 boys and 18 left hips, which were operated on in a mean of 11.5 days after the slip. The mean follow-up was of 38 months. The preoperative Southwick angle averaged 60.69° against 4.52° postoperatively ( p  < 0.001). A larger preoperative slip angle was associated with the development of AVN (RR: 1.05; 95% confidence interval [95%CI]: 1.02-1.07; p  < 0.01). The overall AVN rate was of 26.7%. Function was good or excellent in 86% of uncomplicated hips, and poor in 87.5% of the partients who developed AVN, as graded by the Harris Hip Score. There was no statistical relationship between epiphyseal bleeding and AVN development ( p  = 0.82). Conclusion  The modified Dunn technique is associated with restoration of the femoral alignment and function after unstable SCFE, when uncomplicated. Moreover, it was shown to be reproducible in our population, with a rate of 26% of femoral head necrosis.

Comparing pinning in situ and capital realignment procedures for severe, stable slipped capital femoral epiphysis: a systematic review

In severe, stable slipped capital femoral epiphysis, it is unclear whether pinning in situ (PIS) or capital realignment procedures (CRPs) are superior. Our primary aim was to compare patient-reported outcome measures (PROMs) following each strategy. Secondary aims were to compare rates of femoral head avascular necrosis (AVN) and complications. MEDLINE, Embase and Cochrane databases were searched according to an agreed strategy. Narrative review articles, case reports, letters to the editor and articles not written in English were excluded. The risk of bias was assessed using the Newcastle-Ottawa Scale. Of the 132 citations identified, 127 were excluded following de-duplication and application of the exclusion criteria. Three observational studies comparing PIS with CRP and two case series considering CRP alone were identified. One article was considered fair quality, and four articles were considered poor. In total, 198 hips from five studies were included (66 PIS, 132 CRP). PIS was associated with moderate-good functional outcomes, and CRP with good-high outcomes. Two comparative studies reported significantly better PROMs following CRP. AVN was reported in 1.5% following PIS and 10.6% following CRP. Regarding other complications, chondrolysis occurred in 3.0% following PIS and 2.4% following CRP. Femoroacetabular impingement rates were markedly higher following PIS (60.6% versus 2.3%). Reoperation rates were also greater following PIS (34.5% versus 13.3%). PIS tends to be associated with favourable AVN rates, but CRP with favourable PROMs and complication rates. However, comparisons were drawn from heterogeneous studies lacking long-term follow-up. Further high-quality research is required.

Prevalence of Avascular Necrosis Following Surgical Treatments in Unstable Slipped Capital Femoral Epiphysis (SCFE): A Systematic Review and Meta-Analysis

The choice of treatment for unstable and severely displaced slipped capital femoral epiphysis (SCFE) is controversial. This meta-analysis was conducted to determine the prevalence of femoral head avascular necrosis (AVN) following various treatments for unstable SCFE. Various databases were searched to identify articles published until 4 February 2022. A random-effects model was used to examine prevalence as well as risk ratios with confidence intervals (CIs) of 95%. Thirty-three articles were analyzed in this study. The pooled prevalences of AVN in pinning in situ, pinning following intentional closed reduction, pinning following unintentional closed reduction, and open reduction via the Parsch method, subcapital osteotomy and the modified Dunn procedure were 18.5%, 23.0%, 27.6%, 9.9%, 18.6% and 19.9%, respectively. The risk of developing AVN in pinning following intentional closed reduction was found to be 1.62 times higher than pinning in situ; however, this result was not significant. The prevalence of AVN in open reduction was lowest when performed via the Parsch method; however, this finding should be interpreted with caution, since the majority of slips so-treated are of mild and moderate types as compared with the subcapital osteotomy and modified Dunn procedures, which are predominantly used to treat severely displaced slips. As the risk ratio between intentional closed reduction and the modified Dunn method showed no significant difference, we believe that the modified Dunn method has the advantage of meticulously preserving periosteal blood flow to the epiphysis, thus minimizing AVN risk. In comparison with intentional closed reduction, the modified Dunn method is used predominantly in cases of severe slips.

Is anterior subcapital shortening osteotomy a reliable and reproducible technique in the treatment of severe slipped capital femoral epiphysis?

INTRODUCTION

Proximal femoral shortening osteotomies are becoming the treatment of choice for severe slipped capital femoral epiphysis (SCFE) to reduce the risk of femoroacetabular impingement. The reported rates of complication seem reasonable, but these are single-operator series with surgeons highly experienced in this technique. The purpose of this study was to assess how surgeon experience impacted the outcomes of anterior subcapital shortening osteotomy (ASSO) in severe SCFE.

HYPOTHESIS

The hypothesis was that ASSO is a reproducible technique that is accessible to junior surgeons.

MATERIALS AND METHODS

All ASSOs performed for severe SCFE (slipangle > 40°) between 2015 and 2019 were retrospectively reviewed. All osteotomies were performed by surgeons with less than 4 years' experience (senior residents), who were trained by a senior surgeon experienced in this technique (Group 1). The incidence of femoral head avascular necrosis (AVN) and complications were analyzed and compared to a historical control cohort (Group 2).

RESULTS

A total of 62 SCFEs (37 unstable and 25 stable) were analyzed. Both groups had similar demographic data and SCFE characteristics. The mean operative times were statistically comparable in both groups. The rates of AVN in unstable SCFEs and in the overall series were comparable in both groups (18.9% vs. 13.3%, p=.55 and 12.9% vs. 9.7%, p=.6). These rates were comparable in the stable forms (4.0% vs. 5.4%; p=1). However, the preoperative MRI in Group 1 showed that 42.8% of unstable hips that developed AVN were already hypoperfused before surgery. The overall rate of complication showed no significant difference between the 2 groups (26% vs. 17%, p=.16).

DISCUSSION

Although ASSO is a technically demanding procedure, it is reliable and reproducible. The main risk factor for developing AVN remains the unstable nature of SCFE and not the surgeon's experience. It can be performed by trained junior surgeons, but not in an emergency setting, with the possibility of assistance from a more experienced surgeon.

LEVEL OF EVIDENCE

IV; retrospective case study.

Comparison between anterior cuneiform osteotomy and Dunn procedure in the surgical management of unstable severe slipped femoral epiphysis: A case-control study of 41 patients

BACKGROUND

There is little consensus on the best treatment algorithm for unstable severe slipped capital femoral epiphysis (SCFE). Subcapital osteotomy, which is one of the surgical options, is performed either anteriorly (anterior cuneiform osteotomy, CO) or laterally with trochanteric osteotomy (Dunn procedure, DP). The CO is technically easier and decreases operating time. Moreover, because the DP was the standard in our department before it was replaced by the CO, we had a series of consecutive patients. Therefore, we did a retrospective case-control study in unstable, severe SCFEs treated by CO versus DP, which is to our knowledge the first one aiming to compare: (1) postoperative complications and in particular avascular necrosis, (2) functional outcome, (3) radiologic findings.

HYPOTHESIS

CO is less or just as likely to cause avascular necrosis and has the same clinical and radiologic findings as DP.

METHODS

A total of 41 patients (24 girls, i.e. 58.5%) were included between 2005 and 2018: 23 in the CO group and 18 in the DP group. The median age was 12.9 years (range, 11.5-14.9) and the median slip angle 70̊ (range, 62.5̊-80̊) with a median follow-up of 3 years (range, 2-4). Preoperative, intraoperative, and postoperative clinical and radiologic parameters (Southwick and alpha angles, and femoral head-neck offset) were analyzed, and all complications were documented.

RESULTS

Two (8.7%) cases of avascular necrosis were reported in the CO group and 6 (33.3%) in the DP group (p=.11), with an overall rate of avascular necrosis of 19.5% (8/41). Five out of the 41 patients (12.2%) underwent a total hip arthroplasty: 1/23 (4.3%) in the CO group and 4/18 (22.2%) in the DP group (p=.16). Two (9.5%) patients in the CO group and 7 (38.9%) in the DP group developed postoperative limping before any arthroplasty was performed (p=.055). The alpha angle at follow-up (54±6.1̊ vs. 59.1±7.2̊; p=.027), Oxford hip score at follow-up (17/60 [range, 14-20] vs. 23.5 [range, 19-27]) (p=.021), operating time (132 min [range, 103-166] vs. 199.5 min [range, 142-215]) (p=.011) and intraoperative bleeding (250 mL [range, 100-350] vs. 300 mL [range, 197-450]) (p=.088) were more favorable in the CO group than in the DP group.

CONCLUSIONS

The CO has similar results to DP in the surgical management of unstable severe SCFE.

LEVEL OF EVIDENCE

III; retrospective comparative study.

[Early and late complications and their management in slipped capital femoral epiphysis]

BACKGROUND

Slipped capital femoral epiphysis (SCFE) remains a challenge for the treating surgeon. First of all, SCFE should be diagnosed as early as possible. The earlier the diagnosis is made in adolescents, the lower the slip angle will be. Mild slips show more favourable long-term courses than moderate and severe SCFE.

COMPLICATIONS

With increasing slip angle, the risk of complications increases. The complications of SCFE are diverse, the most severe of which are avascular necrosis (AVN) and chondrolysis. AVN is more common in surgically treated than in non-operatively managed patients and unstable SCFE bears the highest risk of AVN.

THERAPY

Adequate treatment of AVN is still controversial. For surgical treatments, variable rates of AVN have been reported. There is a wide spectrum of surgeries for treating AVN, from hip joint-preserving techniques to total hip replacement. In central Europe there is wide consensus in favour of treating the contralateral side, but this is not without complications. Surgical treatment with in-situ pinning must be carried out with great care to take into consideration the morphology of the femoral head and not to perforate it. It should always be ensured that no osteosynthesis material penetrates the hip joint.