Lateral unicompartmental arthroplasty with the Oxford meniscal knee

We report the results of 53 knees with lateral compartmental osteoarthritis treated by unicompartmental arthroplasty with the Oxford Meniscal Knee. The mean follow-up was 5 years. Eleven knees required further surgery. Six of the revisions were for early dislocation of the meniscal bearing, three because of late infection, one because of loosening of the tibial component and one because of a stress fracture that occurred in the tibial plateau. Since introducing techniques to prevent bearing dislocation, 14 knees have been operated on and there has been one dislocation. This bearing was exchanged for one of a larger size, and the knee subsequently functioned well. Forty of the 42 knees that did not require further surgery had good relief of symptoms and restoration of function, and two had persistent pain. The risk of bearing dislocation in the lateral compartment with the Oxford Unicompartmental Knee replacement is greater than in the medial compartment. In other respects the results are similar. New techniques have reduced the risk of bearing dislocation but have not prevented the complication.