Comparison of Anterior and Posterior Approaches for Hip Resurfacing Arthroplasty: A Gait Analysis Study

Background: Hip resurfacing arthroplasty (HRA) is commonly performed using the posterior approach (POS), which is familiar to most surgeons and allows excellent exposure. The short external rotators and often the gluteus maximus are incised with the POS, which may adversely affect gait. The direct anterior approach (DAA), which is muscle sparing has been shown to preserve more physiological gait patterns in total hip arthroplasty. This study aims to compare outcomes between POS and DAA approaches using gait analysis, the Oxford Hip Score (OHS), Metabolic Equivalent of Task (MET), and EQ-5D. Methods: Seventeen unilateral DAA and 17 POS HRA males were matched for age and BMI. Patients underwent instrumented treadmill gait analysis and completed patient reported outcome scores (PROMs) at a mean of 1.5 (0.9–1.8) years post-operatively. Kinematics and kinetics were recorded using motion capture and force plate data. Group differences were assessed using statistical parametric mapping. These data were compared to a group of 19 healthy male controls matched for age and BMI. Results: Gait analysis postoperatively revealed no significant differences in hip kinematics in either the coronal or sagittal planes between the posterior and direct anterior approaches. Statistical parametric mapping showed no differences in vertical ground reaction forces across the stance phase. Spatiotemporal gait parameters, including top walking speed, cadence, step length, and step width, were comparable between groups and closely aligned with healthy controls. Both cohorts achieved similar postoperative OHS (mean:48, p = 0.651), EQ-5D (median:1.0, p = 0.786), and MET scores (POS:13.1 vs DAA:12.6, p=0.856). Conclusions : This is the first study to analyse gait following HRA via the DAA. Both DAA and POS restored normal gait patterns, with no significant differences in kinematics, kinetics, or spatiotemporal parameters, and results comparable to matched healthy controls. PROMSs were similarly excellent across groups indicating high functional recovery and engagement in moderate-to-vigorous physical activity.