Mid-term results of total hip arthroplasty with modified trochanteric osteotomy in Crowe type IV developmental dysplasia of the hip

BACKGROUND: This study aimed to explore mid-term clinical results of cementless total hip arthroplasty (THA) with modified trochanteric osteotomy in Crowe type IV developmental dysplasia of the hip (DDH). METHODS: Thirteen patients (13 hips) with Crowe type IV DDH who underwent THA with modified trochanteric osteotomy between May 2013 and October 2015 were retrospectively analyzed. The mean follow-up duration was 5.2 years (range, 4.9–6.1 years). RESULTS: The mean Harris Hip Score (HHS) significantly (p < 0.05) improved from 30.7 (range, 22–38) to 87.5 (range, 83–93). The mean leg length discrepancy (LLD) was 53.4 mm (range, 42.1–68.5 mm) preoperatively. The final LLD was 5.6 mm (range, 2.4–9.1 mm; p < 0.05). The mean leg length after surgery was 47.4 mm (range, 33.6–67.2 mm) and the femur shortening distance was 43.8 mm (range, 31.2–53.4 mm). The average duration of bone union for the greater trochanter (GT) was 2.5 months (range, 1.5–3.6 months). There was no infection, GT non-union, or loosening (septic or aseptic) of the stem or cup in any case. CONCLUSIONS: THA with modified trochanteric osteotomy with a cementless cup is an effective treatment for Crowe type IV DDH. It can rebuild complex biomechanics and biology of hip dysplasia without increasing complications.