Total Hip Arthroplasty With Subtrochanteric Osteotomy for Developmental Hip Dysplasia: A Long-term Follow-up Study

BACKGROUND: Total hip arthroplasty (THA) for developmental hip dysplasia (DDH) often requires a subtrochanteric shortening derotational osteotomy (SDO) to limit leg lengthening, mitigate risk of peripheral nerve palsy, and reduce excessive femoral anteversion. Few studies exist detailing long-term clinical outcomes and survivorship. The aim of this study is to analyze the long-term outcomes and survivorship of an SDO-THA cohort. METHODS: We retrospectively reviewed all patients who underwent cementless THA with femoral osteotomy due to Crowe I-IV DDH between 1991 and 2001. Primary outcome measures included revision surgery for any reason and functional outcome measures using modified Harris Hip scores. Secondary outcome measures included mode of implant failure and radiographic assessment for osteotomy union, polyethylene wear, osteolysis, and implant loosening. RESULTS: Our review resulted in 24 SDO-THA cases in 20 patients with a mean follow-up of 19 years (range, 8-27 years). Overall survivorship was 67%. All 8 failures were treated with acetabular revision at a mean time to revision of 11 years (range, 1-25 years). Of the failures, there were 5 cases due to polyethylene wear (62.5%), 2 cases due to acetabular loosening (25%), and 1 case due to recurrent instability (12.5%). The mean postoperative modified Harris Hip score was 76 (range, 52-91) with long-term improvement of 43 points maintained (P < .001). CONCLUSIONS: THA with SDO can produce durable long-term outcomes for the patient with DDH. It is important to consider some common reasons for revision, namely polyethylene wear and osteolysis, acetabular loosening, and recurrent acetabular dislocations.