Acetabular cartilage and labral damage observed during surgical hip dislocation for stable slipped capital femoral epiphysis.

BACKGROUND: Surgical hip dislocation allows the surgeon full visualization of the proximal femur and acetabulum. It also makes it possible to directly observe the pathologic relationship between the proximal femur and acetabular rim with hip motion. The purpose of this study is to classify acetabular cartilage and labral damage that is present at the time of surgical hip dislocation for the treatment of symptomatic stable slipped capital femoral epiphysis (SCFE) hips.
METHODS: A retrospective study was performed at 2 North American centers on patients with a stable SCFE who had a surgical hip dislocation for chronic symptoms. The severity of SCFE (slip angle) was measured as mild (0-30 degrees), moderate (30-60 degrees), and severe (60-90 degrees). The degree of acetabular and labral damage was classified in each patient according to the Beck classification used for femoroacetabular impingement.
RESULTS: Thirty-nine hips in 36 patients that underwent open surgical dislocation for diagnosis of stable SCFE were included. The breakdown of the radiographic severity of the SCFE was 8 mild, 20 moderate, and 11 severe. Labral injury was observed in 34 of 39 hips. Using the Beck classification for labral injury, there were 21 type 1 injuries, 9 type 2 injuries, and 4 type 3 injuries. Cartilage injury was present in 33 of 39 hips. Using Beck classification for cartilage damage, there were 6 grade 0, 5 grade 1, 10 grade 2, 4 grade 3, 10 grade 4, and 4 grade 5 injuries. The average depth of cartilage damage was 5 mm (range, 2-10 mm).
CONCLUSIONS: In this study, significant chondromalacia and labral injury was observed in hips afflicted with SCFE. Surgical hip dislocation allowed direct confirmation of the impingement of the prominent metaphysis on the acetabular labrum and cartilage.