Long-term results after nonconstrained total knee arthroplasty.

In 1975, in Montreal, a nonconstrained total anatomic resurfacing prosthesis was designed. After a follow-up period of ten to 13 years, 79% of knees had an excellent or good result (Hospital for Special Surgery score) and 21% had a fair or poor result. Seven knees had been revised. The flexion range, stability, and capacity to climb stairs normally were significantly better in the knees where both posterior and anterior cruciate ligaments were preserved. Only one knee was revised in the anterior cruciate ligament intact knees. The incidence of aseptic component loosening was 1.2%.