Summary:Obesity is present in a significant percentage of the population, with approximately 97 million overweight adults in the United States alone. Evidence suggests that this percentage is even greater among patients requiring total knee arthroplasty. The possible effects of weight on this procedure have been investigated. Differences in the anatomy, medical history, and pathophysiology have been cited as potential pitfalls when performing surgery on overweight patients. We review how these differences may affect a patient during the preoperative, intraoperative, and perioperative periods and their reported effect on long-term results of the procedure. We think that knowledge of the differences presented by these patients will lead to appropriate modifications in the procedure and patient treatment and may serve to limit the influence of these factors on outcome.