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.