Unicompartmental knee replacement - A minimum 15 year followup study

One hundred forty Marmor cemented unicompartmental knee replacements were i nserted in 103 patients between 1975 and 1982. Fifty-two patients were wome n and 51 were men. One hundred twenty-five were medial compartment knee rep lacements and 15 were lateral knee replacements. At minimum 15 year followu p 34 patients with 48 knee replacements were living; only four patients wit h four knee replacements were lost to followup. Average preoperative and fi nal followup Hospital for Special Surgery knee scores were 57 and 82 points , respectively for the knees of living patients. Average preoperative and f inal followup Knee Society clinical and Knee Society functional scores were 31 and 42, and 85 and 71 points, respectively. For all knees, 10.2% (14 kn ees) were revised [4.4% (six knees) for tibial loosening, 5.1% (seven knees ) for disease progression, and .7% (one knee) for pain]. For patients livin g 15 years, 12.5% (six knees) were revised [2.1% tone knee) for tibial loos ening, and 10.4% (five knees) for disease progression]. Revision for failur e of fixation of these unicompartmental replacements was comparable with th at reported for fixed bearing total knee replacement. Disease progression ( 46%; 62 of 136 knees) and tibial subsidence with wear (10.4%; 15 of 136 kne es, five of which required revision) were the major long term problems in t his group of patients.