Dilemma of high rate of conversion from knee arthroscopy to total knee arthroplasty.

We tried to reduce our rate of conversion from index knee arthroscopy to total knee arthroplasty (TKA) for degenerative pathology (primarily meniscal) in the setting of coexisting arthritis in patients 50 years or older. We hypothesized that, by using a 2-surgeon independent evaluation method, we could reduce the rate to less than 10% by 3-year follow-up. Forty-two consecutive patients were initially evaluated by the knee replacement surgeon to determine if they were TKA candidates. They were then independently evaluated by another surgeon regarding the need for TKA and the possibility of arthroscopic debridement. The data showed a tendency: The under-10% target rate was nearly reached in patients younger than 65 years (12%; 2/17) but not in patients older than 65 years (36%; 9/25). The overall rate of conversion to TKA was 26%. The 2 main groups (arthroscopy only, arthroscopy-plus-TKA) did not differ in all measured characteristics. Failure of our method to achieve better outcomes demonstrates that conventional criteria are poor in predicting which patients with meniscal pathology, which is believed to be relatively more symptomatic than coexisting arthritis, should avoid arthroscopy and go straight to TKA.