EARLY CATASTROPHIC TIBIAL COMPONENT WEAR AFTER UNICOMPARTMENTAL KNEE ARTHROPLASTY

Unicompartmental knee arthroplasty is an appropriate method of treatin g selected patients with osteoarthritis of the medial compartment of t he knee. The common causes of failure are aseptic loosening, infection , patellofemoral pain, and deterioration in the opposite compartment. Seven cases of a cohort of 32 Robert Brigham unicondylar knee replacem ents that failed because of early catastrophic wear of the polyethylen e tibial component are reported, Possible reasons suggested for failur e include inadequate thickness of polyethylene, fusion defects in the polyethylene structure as a result of the sterilization process, incre ased rotational freedom, and reduced conformity in the design of the p rosthesis.