The natural history of unicompartmental arthroplasty : an eight-year follow-up study with survivorship analysis

From 1983 to 1987, 82 unicondylar arthroplasties were performed for primary unicompartmental osteoarthrosis. Seven knees had lateral compartment arthroplasties and 75 had medial unicompartmental knee arthroplasties (UKA). At a minimum follow-up period of four years, eight patients had been revised, one patient was scheduled for revision, and one patient had died with a failed UKA, for a total failure rate of 12%. Reasons for failure were progression of tricompartmental arthritis in two patients (2.4%), polyethylene wear in two (2.3%), component failure in two (2.3%), component loosening in three (3.5%), and technical error in one (1.6%)