Minimally invasive unicondylar versus total condylar knee arthroplasty--early results of a matched-pair comparison.

Fifty consecutive patients with isolated medial compartmental osteoarthritis of the knee were treated with minimally invasive unicompartmental knee arthroplasty (UKA). An equal number of patients with total knee arthroplasty (TKA) performed in the same period were selected and matched with respect to age, pre-operative range of motion and radiological grade of knee arthrosis. Both groups of patients were prospectively followed up. Comparison of the two groups at six months show that patients with minimally invasive UKA have less blood loss, quicker rehabilitation, earlier ambulation, shorter hospitalisation stay and better post-operative range-of-motion with reduced hospitalisation cost. Reflecting on a six-month follow-up and immediate post-operative events, we conclude that minimally invasive UKA is a relatively more cost effective procedure than TKA for these patients.