Body Mass Index Above 35 Has Increased Risk of Complications but Still Achieves Clinically Meaningful Improvement in...

Increased perioperative complications in obese patients undergoing total hip arthroplasty (THA) have previously been reported. There is a relative paucity of data evaluating these complications strictly in the context of anterior-based THA. In this study, we compare the outcomes following anterior-based THA as a function of body mass index (BMI).

A 1:1 matched retrospective cohort study was conducted. Patients undergoing anterior-based THA from January 2022 to June 2024 with a BMI >35 kg/m² were matched 1:1 based on age and sex to patients with a BMI <35 kg/m² from our division registry. Demographic data, surgical details, complications (intraoperative and postoperative), and patient-reported outcome measures (PROMs: 12-Item Short Form P/M, Western Ontario and McMaster Universities Osteoarthritis Index-P/S/F) were collected and analyzed.

There were 280 patients included (140 per group). There were 27 postoperative complications in the BMI >35 kg/m² group and 10 in the BMI <35 kg/m² group (P < .01). There were 10 major complications (4 dislocations, 2 periprosthetic fractures, and 4 deep infections requiring incision and drainage) in the BMI over 35 kg/m² group, with no major complications occurring in the lower BMI group. There were 3 intraoperative complications (periprosthetic fracture), all in patients with BMI >35 kg/m². There was significant improvement in Western Ontario and McMaster Universities Osteoarthritis Index P/S/F scores and 12-Item Short Form pain in both groups at 3 months postoperatively, with greater improvements seen in the BMI >35 kg/m² group.

The present study found that despite significant differences in postoperative complications, there were significant improvements in PROMs in patients with a BMI above and below 35 kg/m² who underwent anterior THA.