The introduction period of unicompartmental knee arthroplasty is critical

One hundred twenty-eight consecutive knees were operated on with the Duracon unicompartmental knee arthroplasty. Of 111 knees, followed 3 years (range, 1-6 years), 109 knees were satisfactory. Two knees were revised because of progression of osteoarthritis and inexplicable pain. Radiostereometric analysis in 49 knees showed a migration of 0.6 mm after 2 years. The magnitude of migration was lower in comparison with published series. In a multicenter study comprising 4 other hospitals, there were 8 revisions in 123 operated knees. The reasons were loosening, subsidence, or fracture. These revisions were within 1 year and mostly related to operative technique. Unicompartmental knee arthroplasty is a demanding procedure that needs special experience and includes a risk of early failures during the introduction of a system.