The association of leg length and offset reconstruction after total hip arthroplasty with clinical outcomes

Abstract Background Restoring native hip anatomy and biomechanics is important to create a well-functioning hip arthroplasty. This study investigated the association of hip offset and leg length after hip arthroplasty with clinical outcomes, including patient reported outcome measures, the Trendelenburg Test and gait analysis. Methods In 77 patients undergoing primary hip arthroplasty for osteoarthritis (age mean = 65 SD = 11 years; BMI mean = 27 SD = 5 kg/m 2 ), hip offset and leg length discrepancy were measured on anteroposterior radiographs. The Western Ontario & McMaster Universities Osteoarthritis Index, the Trendelenburg Test and gait were assessed preoperatively, and at 3 and 12 months postoperatively. An inertial measurement unit was used to derive biomechanical parameters, including spatiotemporal gait parameters and tilt angles of the pelvis. Relationships between radiographic and functional outcomes were investigated, and subgroups of patients with >15% decreased and increased femoral offset were analysed separately. Findings Patient-reported function scores and clinical tests demonstrated a few significant, weak correlations with radiographic outcomes (Spearman's ρ range = 0.26–0.32; p Interpretation Reduced hip offset and leg length discrepancy following hip arthroplasty seem to be marginally associated with worse clinical outcomes.