Patient-perceived outcome measures following unicompartmental knee arthroplasty with mini-incision.

We reviewed 150 patients (183 knees) who underwent mini-incision unicompartmental knee arthroplasty (Oxford). Mean age was 71.5 (36-92) years. Review was conducted at least 12 months following surgery. To assess results, we used the Oxford knee questionnaire, modified Grimby score, return to sport and work, knee "normality" and patient general health. The mean Oxford knee score was 22.17 (range 12-54). Kneeling scored worse than other activities. No significant age or gender difference was found. Mean modified Grimby score was 3.89, equating to moderate exercise less than 2 h a week. Patients with "artificial-feeling" knees had significantly worse scores than patients with normal/near-normal-feeling knees. Patients who returned to/increased sporting activity had better Oxford scores than those who did not. Ninety-four percent of patients working pre-operatively returned to work. Sixty-seven percent continued at the same level of or increased sporting activity. Oxford knee scores and return to sport compared well to published data. Results regarding modified Grimby score, return to work and pain relief were encouraging. The best results were achieved in active patients who felt their health was good and their knee felt normal or near normal following surgery.