Treatment of stable slipped capital femoral epiphysis: systematic review and exploratory patient level analysis

BACKGROUND: Several aspects of slipped capital femoral epiphysis (SCFE) treatment remain controversial. Loder’s work has been instrumental in changing our understanding and approach to the management of the condition when he introduced the concept of “slip instability” and showed that avascular necrosis (AVN) developed in 47% of unstable slips but none of the stable slips. As the two types of SCFE behave differently in terms of presentation, progress and complications, we approached them as two different conditions to highlight these differences. This paper focuses on treatments of stable SCFE. MATERIALS AND METHODS: An extensive literature search was carried out from multiple databases. One thousand six hundred and twenty-three citations were screened. Three hundred and sixteen full publications were obtained for further scrutiny. Fifty-eight studies (2262 hips) were included in the review. These studies evaluated 6 interventions. AVN was chosen as a surrogate for bad outcome. Secondary outcomes were chondrolysis (CL), femoro-acetabular impingement (FAI), osteoarthritis (OA) and patients’ reported outcomes. The latter were pooled when they met our predefined criteria. RESULTS: The type of surgical intervention was an important risk factor. Pinning in situ (PIS) was associated with the lowest AVN rate (1.4%). Moreover, the CL, FAI and OA rates were relatively low in patients who underwent PIS. These were not translated into high patient satisfaction rates among these patients, with only 47% reporting an “excellent” outcome. In contrast, 87% of patients who underwent Ganz surgical dislocation reported an “excellent” outcome. The Ganz surgical dislocation was associated with an AVN rate of 3.3%; double that observed in pinning in situ. CONCLUSION: Pinning in situ is the best treatment for mild and moderate stable slip. Ganz surgical dislocation gives higher patient satisfaction for severe stable slip but the risk of AVN is doubled compared with pinning in situ. Devices that allow continued growth may be better than standard screws. LEVEL OF EVIDENCE: Level III.