Long-term results of the manchester knee. Surface arthroplasty of the tibiofemoral joint

Unicompartmental knee replacement is increasing in popularity. Long-term analysis of an early bi-compartment variety, the Manchester knee, therefore has relevance. One hundred fifty-six consecutive Manchester knee replacements were observed, 47 for longer than ten years. Using survivorship tables, the authors found that the annual failure rate did not increase during the ten-year period. The cumulative success rate was 73% for all knees and 69% for the osteoarthritic ones. The main cause of failure was subsidence. Correction of mechanical axis had no effect on the outcome. Polyethylene wear was not significant clinically or on measurement of retrieved specimens.