Retrospectively, our institution noticed an increased number of patients undergoing total joint arthroplasty (TJA) after bariatric surgery. Considering that bariatric surgery is a proven modality to reduce osteoarthritic pain, we sought to identify a reason some patients may later require TJA. The objective of this study was to investigate the hypothesis that rapid or increased weight loss after bariatric surgery may be a risk factor for TJA.
Weight loss parameters were retrospectively assessed in 15 bariatric surgery patients who subsequently received a primary TJA and compared with matched bariatric controls.
Patients who required a TJA lost 27.9% more of their body mass index (BMI) compared with controls (P = .049). Furthermore, patients who underwent TJA 25-48 months postbariatric surgery lost 78.2% more of their BMI compared with controls (P<.001). Total knee arthroplasty patients lost 43.9% more of their BMI compared with controls (P = .02), and the difference in BMI change for total hip arthroplasty patients was not significant versus controls.
These results contradict the tenant that weight loss is universally protective against arthritis and merit larger prospective investigations.