Does activity affect the outcome of the Oxford unicompartmental knee replacement?
BACKGROUND
High levels of activity are considered to be a contraindication to unicompartmental knee replacement (UKR) and are not recommended after UKR. To determine if these recommendations should apply to the mobile-bearing Oxford UKR, this study assessed the effect of post-operative activity level on the outcome of this device.


METHODS
The outcome of the first 1000 Phase 3 cemented Oxford UKRs implanted between 1998 and 2010 was assessed using survival analysis, the Oxford Knee Score (OKS) and the American Knee Society Objective (KSS-O) and Functional (KSS-F) Scores. Patients were grouped according to the maximum post-operative Tegner Activity Score.


RESULTS
The mean follow-up was 6.1 years (range 1 to 14). Overall, increasing activity was associated with superior survival (p=0.025). In the high activity group, with Tegner≥5 (n=115) 2.6% were revised and the 12-year survival was 97.3% (confidence interval (CI): 92.0% to 99.1%). In the low activity group, with Tegner≤4, (n=885) 4.3% were revised and the 12-year survival was 94.0% (CI: 91.4 to 95.8). The difference between the two groups was not significant (p=0.44). Although the final OKS and KSS-F were significantly better in the high activity group compared to the low activity group (OKS 45v40, KSS-F 95v78), there was no difference in the change in OKS or KSS-O.


CONCLUSIONS
High activity does not compromise the outcome of the Oxford UKR and may improve it. Activity should not be restricted nor considered to be a contraindication.
['Ali|Adam M|AM|', 'Pandit|Hemant|H|', 'Liddle|Alexander D|AD|', 'Jenkins|Cathy|C|', 'Mellon|Stephen|S|', 'Dodd|Christopher A F|CA|', 'Murray|David W|DW|']
D000328:Adult D000368:Aged D000369:Aged, 80 and over D019645:Arthroplasty, Replacement, Knee D005260:Female D005544:Forecasting D006801:Humans D007719:Knee Joint D007720:Knee Prosthesis D008297:Male D008875:Middle Aged D020370:Osteoarthritis, Knee D011474:Prosthesis Design D016059:Range of Motion, Articular D016896:Treatment Outcome
Activity level Unicompartmental knee arthroplasty