Slipped capital femoral epiphysis (SCFE) is relatively common in adolescents and results in a complex deformity of the hip that can lead to femoroacetabular impingement (FAI). FAI may be symptomatic and lead to the premature development of osteoarthritis (OA) of the hip. Current techniques for managing the deformity include arthroscopic femoral neck osteochondroplasty, an arthroscopically assisted limited anterior approach to the hip, surgical dislocation, and proximal femoral osteotomy. Although not a routine procedure to treat FAI secondary to SCFE deformity, peri-acetabular osteotomy has been successfully used to treat FAI caused by acetabular over-coverage. These procedures should be considered for patients with symptoms due to a deformity of the hip secondary to SCFE. Slipped capital femoral epiphysis (SCFE) is the most common adolescent disorder of the hip and the incidence is likely to increase, given the current epidemic of obesity in childhood. 1,2 It has been reported that the age at onset decreases with increasing obesity. 3 SCFE creates a complex deformity of the hip that can result in femoroacetabular impingement (FAI), which may lead to the early development of osteoarthritis (OA) of the hip. 4 Retrospective studies of patients with untreated SCFE and of pinning in situ without realignment suggest that the severity of the slip correlates with the subsequent radiological evidence of OA and poor clinical outcome scores, but is not necessarily predictive of FAI. 5,6 In a retrospective study by Dodds et al, 6 32% of patients (16 of 49) who previously presented to their institution with SCFE were found to have clinical signs of FAI.In situ pinning is commonly undertaken and is a relatively low risk procedure relying on remodelling of the proximal femur. However, it may still result in radiological osteoarthritic changes and a poor clinical outcome. Surgical management of FAI is aimed at restoring a more normal femoral head-neck offset in order to increase clearance and prevent femoral abutment against the acetabular edge. Various management strategies have been described, including arthroscopic osteochondroplasty, arthroscopically assisted osteochondroplasty via arthrotomy, surgical dislocation osteochondroplasty, proximal femoral osteotomy and peri-acetabular osteotomy.
PathophysiologyBased on the type of abnormal morphology, FAI can be divided into three types: cam, pincer, and mixed-type. 4 In cam-type impingement the prominent area, typically on the anterolateral femoral neck, abuts the acetabular rim during forceful movement, especially in flexion and internal rotation, leading to damage of the labral-chondral complex. 7 In pincertype impingement the abnormality is on the acetabular side, involving focal or global overcoverage of the femoral head leading to damage of the femoral head-neck region and labrum. 8,9 FAI can also be classified as primary and secondary (Fig. 1).In SCFE, the relative positioning of the femoral head leads to prominence of the anterolateral femoral metaphysis (Fig. 2). 10 Th...