THE IMPACT OF BODY MASS INDEX ON TIME TO FULL FUNCTIONAL RECOVERY FOLLOWING TOTAL HIP ARTHROPLASTY: A SYSTEMATIC LITERATURE REVIEW

Obesity represents a growing global health challenge with significant implications for orthopedic surgery outcomes. Total hip arthroplasty (THA) is one of the most common and successful procedures for treating end-stage hip osteoarthritis. The influence of high body mass index (BMI) on postoperative functional recovery requires our attention due to the seriousness of this issue. This systematic literature review aimed to evaluate the impact of BMI on time to full functional recovery following primary total hip arthroplasty, examining evidence from Polish and international studies. Outcomes assessed included Harris Hip Score (HHS), Hip disability and Osteoarthritis Outcome Score (HOOS), gait analysis parameters, complication rates, and time to functional independence. Based on the studies analyzed, it can be observed that elevated BMI primarily contributes to an increased risk of perioperative complications and revision surgeries. Short-term functional recovery (<6 months) showed small differences favoring non-obese patients, but these differences remained below minimal clinically important difference thresholds. By 6-12 months post-surgery, functional gains were comparable between obese (BMI ≥30 kg/m²) and non-obese patients. Obese patients demonstrated significant improvements in gait speed and hip range of motion, with functional gains comparable irrespective of BMI. However, morbidly obese patients (BMI ≥35 kg/m²) experienced higher revision rates (7.99% vs 2.75%, p<0.0001) and increased complication rates. Postoperative complications including surgical site infections (11.83% vs 4.30%, p=0.05) and prolonged hospital stays (7.6±2.1 vs 5.4±1.7 days, p<0.001) were significantly elevated in obese patients.