Innovative Hip Distraction Approaches for Total Hip Arthroplasty in Crowe IV Developmental Dysplasia or Similar High-Riding Patients.

INTRODUCTION: Total hip arthroplasty (THA) for dislocated hips (Crowe IV dysplasia) presents unique challenges. Conventional approaches involve subtrochanteric osteotomies, but are complex with additional fixation and potentially lead to limb-length discrepancies, nerve palsies, and other complications. An alternative strategy is a staged approach, where the femoral head (or remnant) is gradually lowered (distraction technique) to align with the true acetabulum over a period of time, followed by a second-stage anatomically acetabular-positioned THA. External fixation distraction and telescoping internal lengthening devices have been utilized to achieve pre-operative alignment. We evaluated these techniques, including the types, time, and amount of distraction needed, as well as outcomes and complication rates.

METHODS: In this retrospective case series, 14 patients (9 women, 5 men), who had a mean age of 32 years (range, 16 to 67), underwent staged surgical interventions using hip distraction using external fixators or internal lengthening devices for hip dysplasia and other pathologies (Perthes disease, osteonecrosis) in preparation for a second-stage anatomically-placed THA. The mean follow-up duration for external-fixation patients was 10 years (range, 6.5 to 13.4).

RESULTS: Staged treatment involved external fixators (n = 8) or internal lengthening devices (n = 6) with a device placement mean of 48 days (range, 42 to 71). The amount of distraction ranged from 6 to 12 centimeters. There were two patients who required uncomplicated revision of the internal lengthening devices, and another patient had a temporary peroneal nerve palsy. There was one patient who underwent an acetabular revision at 7 years.

DISCUSSION: We focused on a challenging patient cohort that emphasizes the efficacy of staged interventions in managing Crowe Type IV dysplasia and similar cases. Favorable outcomes were found with the immediate transition to THA after device removal that effectively addressed soft-tissue contractures and femoral migration. Despite the need for further validation via larger, prospective studies, this innovative approach may pave the way towards optimizing this strategy for these difficult hip pathologies.