Abstract
Unicompartmental knee arthroplasty remains controversial in some quarters and has been subject to recent negative press. The aim of the present study was to determine the differences in pre-operative status and early post-operative improvement between patients having unicompartmental knee Replacement (UKR) and Total Knee Replacement (TKR).
Methods: A Prospective study. Ethical approval was obtained prior to the study. Patients undergoing knee arthroplasty by two orthopaedic surgeons were included. Decision to proceed to unicompartmental or total knee replacement was at the surgeons’ discretion and was not randomised. The Oxford and the Ameri-can Knee Society scores were used to assess outcome. (Oxford score was used as a 0–48 scale; 0 being better and 48 worse). Scores were documented pre-operatively and at six weeks post-operatively.
Results: 104 patients were included in the study. 84 patients had TKR and 20 patients had UKR. Patients under going TKR had significantly worse Oxford, knee and function scores pre-operatively (32.2, 29.2 and 39.6) as compared with the UKR patients (28.5, 40.5 and 46.7) (P= 0.03, 0.001 and 0.026 respectively). TKR was associated with greater improvements in Oxford (P= 0.025), knee (P=0.0.027) and function (p=0.06) scores. However, the post operative scores were comparable; 20.4, 78.9 and 58.7 for TKR and 20.7, 80.9 and 57.9 for UKR.
Conclusions: It could perhaps be expected that patients with unicompartmental disease would have better pre-operative knee status than patients with more advanced multicompartmental disease. It is therefore understandable that patients receiving total knee replacements are able to improve more post-operatively than those receiving unicompartmental devices. Unicompartmental knees achieve only marginal initial superiority in terms of knee scores at 6 weeks follow-up. This is important and if clinical superiority and prosthesis longevity are not proven at longer term follow-up it would question the use of unicompartmental arthroplasty.
Correspondence should be addressed to: BASK c/o BOA, at the Royal College of Surgeons, 35–43 Lincoln’s Inn Fields, London, WC2A 3PE, England.
