Does body mass index affect outcomes of ambulatory knee and shoulder surgery?

Purpose Obesity is highly prevalent among patients with knee and shoulder injuries and is associated with greater odds of surgical treatment for these injuries. The purpose of this systematic review was to summarize the literature that has examined the association between body mass index (BMI) and outcomes of ambulatory knee and shoulder surgery. Methods A literature search of PubMed and Medline was conducted up to December 2013. Studies that examined the association between BMI and outcomes after ambulatory knee and shoulder surgery (arthroscopy, repairs, and reconstructions) were included. Outcomes included postoperative functional scores, clinical scores, and complications. Results Eighteen studies were included in this review; 13 involved knee surgery and 5 involved shoulder surgery. Seven knee studies and 2 shoulder studies found increased BMI to be associated with worse postoperative outcomes, whereas the remaining 9 studies did not find an association. Increased BMI was associated with worse clinical scores and less patient satisfaction after arthroscopic meniscectomy or debridement, and with worse clinical scores and lower activity levels after anterior cruciate ligament (ACL) reconstruction. It was also associated with worse clinical scores and a longer hospital stay after rotator cuff repair and with longer time to return to work after subacromial decompression. Six studies examined the association between BMI and complications, but all reported null findings. Conclusions There is a lack of consensus in the literature regarding the association between BMI and ambulatory knee and shoulder surgery. Several factors may have contributed to contradictory findings, including variation in measuring and classifying anthropometry, postoperative outcomes, and follow-up time. Level of Evidence Level IV, systematic review of Level I, III, and IV studies.