Short-term Outcomes in obese patients undergoing anterior minimally invasive total hip arthroplasty

Abstract

Introduction: Obesity affects over 774 million individuals worldwide. It is associated with an accelerated onset and progression of osteoarthritis, resulting in an increased need for total hip arthroplasty (THA). Obese patients have a higher risk of perioperative complications. The direct anterior approach (DAA) for THA is gaining popularity globally, however, there are concerns over its suitability for obese individuals. This study compares short-term clinical, functional, and radiological outcomes of obese and non-obese patients undergoing THA via the DAA. Methods: We conducted a retrospective study of 356 consecutive patients who underwent elective primary THA via the DAA using a specialised leg positioner (Medacta International, Switzerland) and intraoperative fluoroscopy. Obese patients (BMI - 30 kg/m2 ) were compared to the control group using baseline patient information, perioperative data and postoperative outcomes at minimum one-year follow-up. Results: The study included 107 (30%) obese patients. Cohorts were well-matched for age, sex, preoperative diagnosis and baseline PROMs. In the obese cohort, surgical time and blood loss increased by a mean of 8.32 - 6.9 minutes (p = 0.03) and 58.19 - 25.37 ml (p = 0.0003) respectively. There were no significant differences in intraoperative radiation (mGys), time to discharge and discharge destination between the groups. Obese patients had a higher incidence of wound-related complications (5.6% versus 2.4%), however overall complication rates were similar (9.3% versus 6.8%, p = 0.67). Functional outcomes were equivalent with a mean postoperative mHHS of 97.57 - 4.86 and 98.05 - 5.59 in the obese and non-obese cohorts respectively (p = 0.54). PROMs including the Forgotten Joint Score (p = 0.34), Patient Joint Perception score (p = 0.2) and patient satisfaction rates (p = 0.085) were comparable. Conclusion: The AMIS - DAA is a safe and effective approach for obese patients with excellent short-term outcomes, however an increased risk of wound-related complications remains.