Body Mass Index > 40 Is Not Correlated With Early Complications in Patients Undergoing Primary Total Joint Arthroplasty at an Ambulatory Surgical Center.

Introduction: Morbid obesity (body mass index [BMI] > 40) is associated with complications following total joint arthroplasty (TJA) and often prevents same-day discharge. However, advances in medical optimization are reshaping how patients who have a higher BMI are evaluated. This study examined whether modern preoperative optimization strategies can enable safe TJA for patients who have elevated BMIs at an ambulatory surgery center (ASC) by comparing complication rates (24-hour, one to 90-day) of patients in different BMI classes.

Methods: We retrospectively analyzed 2,367 patients who underwent primary TJA at an academic ASC from January 21, 2021, through September 18, 2024. Patients were categorized into five BMI groups per National Institutes of Health and World Health Organization reference ranges: normal weight (BMI < 25; n = 368), overweight (BMI 25 to < 30; n = 717), obesity class 1 (BMI 30 to < 35; n = 675), obesity class 2 (BMI 35 to < 40; n = 417), and obesity class 3 (BMI ≥ 40; n = 190). Differences in presurgical wait times, intraoperative data, post-anesthesia care unit (PACU) data, and complication rates were analyzed.

Results: There was no significant difference in immediate (24-hour) complications and complications between one and 90 days between BMI groups (P = 0.19 and P = 0.63, respectively). Increasing BMI did not correlate with higher complication rates when controlling for other covariates. Higher BMI was associated with longer presurgical wait times, shorter PACU time, and higher final PACU pain scores before discharge.

Conclusion: This study underscores the importance of personalized medical optimization in enhancing the safety of TJA for patients who have elevated BMIs. Focusing on management of preoperative comorbidities and custom surgical planning can achieve outcomes comparable to those of patients who have normal BMIs at ASCs, questioning BMI as an exclusion criterion and advocating for more inclusive, evidence-based patient selection.