Functional Recovery After Hip Arthroplasty with a Minimal Invasive or Classical Approach Eight Years After Intervention

<b>Background:</b> The aim of this study was to investigate differences in functional recovery eight years after total hip arthroplasty in patients who underwent hip joint surgery using two different approaches: the classic lateral approach and the anterolateral minimally invasive surgical approach. <b>Methods:</b> Eight years after the hip replacement, 68 subjects, 32 in the classic and 36 in the minimally invasive group, underwent follow-up measurements involving the Harris Hip Score (HHS), range of motion, strength of the abductor muscles, 50-m walk time, body mass index (BMI), physical activity questionnaire, and visual analogue scale (VAS) pain during general activities. <b>Results:</b> Higher HHS (<i>p</i> < 0.001), hip abduction (<i>p</i> < 0.001), and hip flexion (<i>p</i> = 0.018) range of motion values were obtained in the minimally invasive approach group. A correlation between physical activity (PA) and the hip abduction muscle strength in the classic group (r = 0.43; <i>p</i> = 0.011) and a correlation between PA and the HHS in the minimally invasive group (r = 0.34, <i>p</i> = 0.041) was found. BMI was correlated with the 50-m walk time in both groups (classical: r = 0.39; <i>p</i> = 0.027; minimally invasive r = 0.35; <i>p</i> = 0.030); meanwhile, in the minimally invasive group, BMI was negatively correlated with hip flexion (r = -0.37; <i>p</i> = 0.020). <b>Conclusions:</b> Eight years after total hip arthroplasty, performed using either an anterolateral minimally invasive or lateral approach, there was no difference in the patients' functional outcome in relation to BMI. The minimally invasive approach benefits patients by granting them better functional abilities. A clinical difference was found in the HHS, in favour of the minimally invasive group.