Total Knee Replacement: Summary

Total knee arthroplasty is one of the most common orthopaedic procedures performed. In 2001 171,335 primary knee replacements and 16,895 revisions were performed.1 Throughout this report we use the term total knee arthroplasty (TKA) in lieu of total knee replacement because the abbreviation for the latter may be readily confused with total knee revision. Because these procedures are elective and expensive (Medicare paid approximately $3.2 billion in 2000 for hip and knee joint replacements) and because the prevalence of arthritis is expected to grow substantially as the population ages,2, 3 these procedures are likely to come under increasing scrutiny. Previous reports suggest that TKAs improve functional status, relieve pain, and result in relatively low perioperative morbidity.4 However, based on conclusions from consensus panels or surveys of health care providers, there is considerable disagreement about the indications for the procedure; that is, which patients are most likely to benefit from TKA and, conversely, in which patients is TKA contraindicated or of low value.5-10 This evidence report, which was commissioned for an NIH Consensus Development Conference on Total Knee Replacement, was designed to systematically review, analyze, and discuss empirical data on Total Knee Replacement, to help inform the deliberations of the Consensus Panel. In collaboration with the Office of Medical Applications of Research (OMAR), the National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS), and the TKR Planning Committee, the Agency for Healthcare Research and Quality (AHRQ) defined the work to be performed for a comprehensive evidence report on the indications for primary TKR and revisions. The scope of the project specified that it address the following key questions regarding total knee arthroplasty: 1. What are the current indications for, and outcomes from, primary total knee replacement? 2. How do specific characteristics of the patient, material and design of the prosthesis, and surgical factors, affect the short-term and long-term outcomes of primary total knee replacement? 3. Are there important perioperative interventions that influence outcomes? 4. What are the indications, approaches, and outcomes for revision total knee replacement? 5. What factors explain disparities in the utilization of total knee replacement in different populations? 6. What are the directions for future research?