An analysis of body weight changes after shoulder arthroplasty.

Background: To determine if there are postoperative weight changes for patients undergoing primary shoulder arthroplasty (SA). In addition, we aimed to determine if glycemic control (hemoglobin A1C levels) change postoperatively for patients undergoing SA.

Methods: All patients 18 years of age or older who had undergone primary SA over a 12-year period were analyzed. Patients were excluded if they did not have a preoperative body mass index or if they had less than 1-year follow-up. Baseline demographics were recorded for all patients and comparisons were made between the obese and nonobese groups. Clinically meaningful weight loss was defined as a ≥ 5% reduction in body weight postoperatively.

Results: A total of 469 patients met inclusion criteria. Of them, 65% of patients were obese, and the mean preoperative body mass index for all patients was 33. With a mean follow-up of 40 months, 70% of patients demonstrated clinically significant weight loss. Compared with patients without obesity, patients with obesity lost significantly more weight (10 vs. 6 kg) and demonstrated significantly greater postoperative body mass index reductions (4 vs. 2). Overall, 72% of patients with obesity demonstrated clinically meaningful postoperative weight loss of ≥5% body weight. Patients with obesity who lost weight also saw a decrease in their postoperative hemoglobin A1C: for every 10 pounds of weight loss, A1C decreased by 0.08 units.

Conclusions: In our series, 72% of patients with obesity undergoing primary SA achieved clinically meaningful weight loss, with a mean follow-up of more than 3 years. Patients who lose weight after SA additionally demonstrate improved glycemic control. Surgeons and patients should balance the association between postoperative weight loss after SA with the potential increased risks of operative complications, particularly for severely obese patients.