Reduced invasive approach for Oxford II medial unicompartmental knee replacement — a preliminary study

Nineteen patients (20 knees) who underwent consecutive Oxford Phase II unicompartmental arthroplasty for anteromedial osteo-arthritis were prospectively evaluated to determine whether performing the operation with a reduced exposure improved their functional recovery as compared to the traditional midline skin incision and lateral dislocation of the patella. Alternative knees underwent either approach. In 10 knees, a reduced medial arthrotomy incision was used without dislocations of the patella. In the other 10, a standard paramedial arthrotomy incision was employed with dislocation and eversion of the patella. In the former group post-operative recovery of straight leg raising, flexion to 90° and ability to climb stairs was achieved approximately 3 days earlier than in the second group. No complications occurred and, 3 months after surgery, the two groups had achieved similar recovery. There was no radiological evidence of impaired cementation or orientation of the prostheses implanted through the smaller incision.