Flat-on-flat, posterior cruciate ligament-sparing total knee prostheses recently have shown problems of wear, loosening, and multiple design changes. Two thousand one Anatomical Graduated Components total knee arthroplasties with compression molded, nonmodular polyethylene tibial components were done between 1983 and 1991 at 3 institutions. AH knees were evaluated clinically and radiographically every 2 to 3 years; 71 knees were seen in follow up >10 years. There were 8 failures secondary to revision (5 tibial failures; 2 secondary to metalosis from patellar polyethylene dissociation; and 3 femoral failures) resulting in a 98% survival rate at 10 years. The tibial design was flat-on-flat with a compression molded polyethylene that the authors believe is the primary reason for its success.
From *The Center for Hip and Knee Surgery, Mooresville, IN.
**Advanced Orthopaedic Centers, Richmond, VA.
†Massachusetts General Hospital, Boston, MA.