Analysis of biomechanical gait parameters in patients after total hip replacement operated via anterolateral approach depending on size of the femoral head implant: retrospective matched-cohort study

INTRODUCTION: Total hip replacement (THR) is considered one of the most effective medical procedures in treatment of osteoarthritis. Since its introduction, there has been a worldwide debate over proper implant selection in terms of size, bearing type and shape. Following study was designed to assess the importance of femoral head size in long-term follow-up. MATERIALS AND METHODS: A cohort of 30 patients with primary end stage osteoarthritis who underwent total hip replacement was analysed retrospectively. A homogenous group was chosen with no major differences in BMI. Patients’ gait parameters were measured in a biomechanics laboratory using the 3D BTS Smart system. WOMAC and VAS questionnaires were used to assess patient reported outcome. RESULTS: The subgroup with larger implant head size had several outcomes significantly superior to the subgroup with standard head size and non-inferior to healthy hips. Following variables were measured during this study: time of support phase, time of swing phase, double support time, walking hip extension angle. CONCLUSIONS: Use of larger sized femoral heads during THR gives better results in terms of gait pattern. Since restoring the gait pattern is one of the aspects of rehabilitation and returning to daily activities it seems to be an important observation.