Patients with multiple sclerosis have higher rates of worsening following total hip arthroplasty: a propensity-matched analysis

Introduction: The progressive nature of multiple sclerosis (MS) may adversely affect outcomes following total hip arthroplasty (THA). As patient-reported outcome measures (PROMs) in this specific group are not well defined, this study aimed to compare the clinical outcomes and the rates of achieving the minimal clinically important difference for improvement (MCID-I) and worsening (MCID-W) between patients with MS and those without MS undergoing THA. Methods: We conducted a retrospective analysis of 375 THAs, including 75 MS patients and 300 propensity-matched non-MS patients (4:1), performed between 2016 and 2022. Collected PROMs included Patient-Reported Outcomes Measurement Information System (PROMIS) Global Health Mental and Physical, PROMIS Physical Function short form 10-a (PF-10a), and Hip disability and Osteoarthritis Outcome Score-Physical Function Short-form (HOOS-PS). Preoperative and postoperative PROMs and MCID-I/MCID-W rates were compared. Results: A total of 375 THAs, including 75 MS and 300 matched non-MS patients, were analysed. MS patients had higher 90-day postoperative complication rates (9.3% vs. 2.3%, p = 0.012) and infection rates (4.0% vs. 0.3%, p = 0.006). The rates of achieving MCID-I and MCID-W were similar for PROMIS Global Mental, PROMIS Global Physical, and HOOS-PS, but MS patients had a higher rate of experiencing MCID-W for PROMIS PF-10a compared to non-MS patients (16.7% vs. 6.5%, p = 0.022). Additionally, MS patients had a longer mean hospital stay (2.4 vs. 1.9 days, p = 0.005) and lower rates of being discharged home (82.7% vs. 94.3%, p < 0.001). Conclusions: The present study found that MS patients experience similar rates of MCID-I and MCID-W in most PROMs but have a higher rate of MCID-W for PROMIS PF-10a and increased postoperative complications. These findings highlight the need for careful consideration of postoperative risks despite potential improvements. Further research is needed to explore the impact of MS progression on PROMs and perioperative outcomes.