Does bariatric surgery really benefit patients before total knee arthroplasty? A systematic review and meta-analysis

At present, whether bariatric surgery before total knee arthroplasty (TKA) affects the prognosis of subsequent TKA has been a topic of debate in the academic community. The primary purpose of this systematic review and meta-analysis was to investigate the effect of previous bariatric surgery on prosthetic revisions and postoperative complications after TKA. We included prospective and observational studies published in English involving patients who had undergone bariatric surgery prior to TKA and compared them with morbidly obese patients with no history of bariatric surgery. The Newcastle-Ottawa Scale was used to assess the methodological quality of non-randomized case-control studies. The outcomes included revisions, infections, venous thromboembolism (VTE), blood transfusion, mortality, stiffness or manipulation under anesthesia (MUA), and medical complications. Of the 9 included studies with 166047 patients, 4 were matched cohort studies, 2 were unmatched cohort, and 3 were database studies. Methodological quality was high in ten studies and moderate in thirteen studies. Our analysis demonstrated that patients with TKA who had undergone prior bariatric surgery were associated with increased risks of long-term revision, long-term infection, long-term stiffness or MUA and blood transfusions, whereas prior bariatric surgery did not increase the risk of short-term complications and short-term revision. This meta-analysis highlights the risks of bariatric surgery prior to TKA and suggests that prior bariatric surgery may increase the risk of perioperative blood transfusion and also the risk of revision and infection in long-term follow-up. Surgeons can use this information to help counsel patients undergoing bariatric surgery before primary TKA.