Why knees fail in 2011: patient, surgeon, or device?

The outcome of total knee arthroplasty (TKA) is influenced by multiple interconnected factors, including patient selection, implant design, and surgical technique. Total knee arthroplasty has been shown to be highly successful, with patient satisfaction rates reported from 85% to 95% with low rates of failure, but if failure occurs, its impact is significant. In 2003, 402,000 primary TKAs and 32,000 revision TKAs were performed in the United States, and the number of TKAs is expected to double by 2015. Recent data on modern implant designs and techniques have demonstrated a surprising number of early failures, although the true number of early failures is unknown. Patient medical comorbidities should be optimized preoperatively, while psychosocial issues and workers compensation are more nebulous yet contribute greatly to patient perceived outcomes. Understanding current failure mechanisms of primary TKA and how to prevent complications will be critical to help manage a potentially overwhelming TKA revision burden. This article discusses failure rates as well as factors from the patient, surgeon, and device, that contribute to TKA failure.