METHODS

A retrospective review of 188 cemented, fixed bearing unicompartmental (UNI) knee replacements implanted between January 2009 and June 2012 at 3 centers. The purpose of this study was to evaluate the survivorship, reasons for revision, radiographic and clinical results. A chart review was performed to collect demographics, operative details, American Knee Society (AKS) scores and adverse events (AE) through 2-years post-op. Kaplan-Meier (KM) device survivorship rates for the partial knee construct were estimated for post-op years in which at least 40 subjects had later follow-up. The definition of revision was the removal of any component for any reason, and device survivorship was the lack of revision. The time variable was the time to revision if the knee had been revised, or the time to last clinical follow-up or death if the knee had not been revised.

The average follow-up was 2.03 years (SD=0.4). The mean age was 64 years (SD=10.5), 56% of the patients were 65 years or younger, mean BMI was 27.5 kg/m2 (SD=4.9), 60% of patients were women, and 89% had a diagnosis of OA (9.6% had AVN). Data were collected through April 2015.