To assess revision rates after knee arthroplasty we compared cumulative results from world wide clinical studies and arthroplasty registers from the 1960 up to now in one of the largest reviews ever [1]. We found, the overall revision rate at ten years was 6% for total knee arthroplasty (TKA) and17%for unicondylar protheses (UKA). Literature from non-register studies are biased regarding UKA [2]. After the first revision, the five year revision rate was 3% for TKR and 9% for UKR [3].
Therefore, it can be calculated that revision rate after 15 years for TKA is 9% (6% + 3%) and rate for UKR is 26% (17%+9%). We therefore compared two treatments options with a different outcome.Since the average patients receiving UKRare younger than the average patients receiving TKR, it is therefore questionable to treat the younger patients with a treatment option with a 3-fold higher revision rate (26% instead of 9%). In my opion, UKR shall be reserved for older patients and not for younger patients.