In previous studies conducted outside the US, ∼20% of total knee arthroplasty (TKA) surgeries were judged to be inappropriate. The present study was undertaken to determine the prevalence rates of TKA surgeries classified as appropriate, inconclusive, and inappropriate in a knee osteoarthritis population in the US.
We used a modification of a validated appropriateness classification system and applied it to patients in the Osteoarthritis Initiative data set who underwent TKA. A variety of preoperative data were used in the classification, including Western Ontario and McMaster Universities Osteoarthritis Index pain and physical function scores, radiographic features, knee motion and laxity measures, and age.
Data on 205 patients who underwent TKA were examined. The prevalence rates for classification of the procedure as appropriate, inconclusive, and inappropriate were 44.0% (95% confidence interval [95% CI] 37-51%), 21.7% (95% CI 16-28%), and 34.3% (95% CI 27-41%), respectively.
Approximately one-third of TKA surgeries were judged to be inappropriate. Variation in the characteristics of patients undergoing TKA was extensive. These data support the need for consensus development of criteria for patient selection among US practitioners treating patients who are potential candidates for TKA. Among the important issues, consensus development needs to address variation in patient characteristics and the relative importance of preoperative status and subsequent outcome.