30 Jun Many Knee Replacement Surgeries Classified As Inappropriate
MedicalResearch: What are the main findings of the study?
Dr. Riddle: We used a classification system developed by researchers in Spain in the late 1990s and found that classifications of appropriate, inappropriate and inclusive ratings for persons undergoing knee replacement surgery were 44.0%, 21.7%, and 34.3%, respectively. We studied 175 persons who underwent unilateral total knee replacement in the Osteoarthritis Initiative study, an NIH and privately funded multi-year cohort study of persons with are at high risk for knee osteoarthritis. These findings need to be considered cautiously because the classification system was developed more than 15 years ago and was designed to place greatest priority on persons with end stage knee osteoarthritis and severe pain and functional loss.
MedicalResearch: Were any of the findings unexpected?
Dr. Riddle: We expected to find a lower percentage of persons classified as inappropriate but some of the inflation in inappropriate rankings was likely due to the greater emphasis on persons with end stage knee OA and severe pain and functional loss.
MedicalResearch: What should clinicians and patients take away from your report?
Dr. Riddle: Patients should have a clear understanding of both the potential benefits and risks of knee replacement surgery and patients should clearly explain their expectations to the surgeon so that both the patient and surgeon can discuss in a clear way the expected outcome. Patients should complete validated pain and functional status questionaires because the strongest prognostic indicator of outcome is pre-operative pain and functional status. Patients should ask their surgeon about the extent of arthritis in their knees and this information should be shared with the patient. The extent of radiographic knee OA is also an important prognostic indicator of outcome.
MedicalResearch: What recommendations do you have for future research as a result of this study?
Dr. Riddle: Future research should examine the post-surgical outcome for these different classification groups to determine the extent to which classification might affect future pain and functional status. Key stakeholders including surgeons, patients, and other members of the healthcare team along with policy makers should convene meetings to discuss indications for knee replacement surgery and to try to come to consensus on clear indications to attempt to reduce unwanted variation. For example, we found that approximately 10% of persons undergoing knee replacement surgery have no joint space narrowing on x-ray and another 10% have mild pain and minimal functional loss. The procedure is already known to be highly effective and cost effective for most patients but our study sheds light on the fact that some patients may not be ideal candidates for the procedure.
Using a Validated Algorithm to Judge the Appropriateness of Total Knee Arthroplasty in the United States: A Multi-Center Longitudinal Cohort Study
Daniel L. Riddle, William A. Jiranek and Curtis W. Hayes.
Arthritis & Rheumatology; Published Online: June 30, 2014 (DOI: 10.1002/art.38685).