Comparing the Pemberton osteotomy and modified San Diego acetabuloplasty in developmental dysplasia of the hip

PURPOSE: Patients with developmental dysplasia of the hip (DDH) may require a pelvic osteotomy to treat acetabular dysplasia. The Pemberton osteotomy and modified San Diego acetabuloplasty are two options available when surgically treating DDH. The purpose of this study was to compare outcomes following the Pemberton and modified San Diego when treating patients with acetabular dysplasia in typical DDH. METHODS: We included 45 hips in the modified San Diego group and 38 hips in the Pemberton group. Hips with less than two years follow-up and patients with a neuromuscular diagnosis were excluded. Clinical outcomes were rated using the modified McKay criteria with radiographic outcomes graded using the Severin score. Avascular necrosis (AVN) was assessed using the Kalamchi and MacEwen criteria. RESULTS: Mean follow-up was 4.9 years (2.1 to 11.2). Both procedures produced similar decreases in the acetabular index (modified San Diego: 17.0˚ versus Pemberton: 15.2˚; p = 0.846). Most hips had good/excellent results using the modified McKay criteria (modified San Diego: 78%, Pemberton: 94%; p = 0.055). Most hips were rated as good/excellent on the Severin scale (modified San Diego: 100%, Pemberton: 97%, p = 0.485). The proportion of hips with AVN grade 2 or higher were similar between groups (modified San Diego: 0%, Pemberton: 3%; p = 0.458). CONCLUSION: The modified San Diego acetabuloplasty is a safe and effective alternative to treat acetabular dysplasia in patients with typical DDH. By maintaining an intact medial cortex, acetabular reshaping can be customized to address each patient’s specific acetabular deficiency LEVEL OF EVIDENCE: Level III retrospective comparison