Objective: To provide estimates of patient outcomes following tricompartmental knee replacement and to examine variation in outcomes due to patient and prosthesis characteristics.
Data sources: English-language articles identified through a computerized literature search and bibliography review.
Study selection: Studies were included if they enrolled 10 or more patients at the time of initial knee replacement and measured patient outcomes using a global knee-rating scale.
Data extraction: Each study was subjected to a blinded qualitative assessment and unblinded abstraction of patient characteristics, surgical techniques, and outcomes.
Data synthesis: A total of 130 studies reporting patient outcomes on 154 cohorts satisfied inclusion criteria. The total number of enrolled patients was 9879 with a mean enrollment of 64.1 patients. The mean follow-up was 4.1 years. The mean patient age was 65.0 years, 71.7% of patients were women, 62.6% had osteoarthritis, and 26.6% underwent bilateral knee replacement. Global rating scale scores improved by 100% for the typical enrolled patient, and 89.3% of patients reported good or excellent outcomes. Anatomic classification of the prosthesis, percentage of enrolled patients with osteoarthritis, publication year, and number of enrolled patients explained 27% of the variation in reported mean postoperative global rating scale scores. The weighted mean complication rate was 18.1%, and the mean mortality rate per year of follow-up was 1.5%. The overall rate of revision during 4.1 years was 3.8%.
Conclusions: Tricompartmental knee replacement was a safe and effective procedure for the patients reported in these studies. The knee pathology and the type of prosthesis were significant predictors of outcomes. Limitations in the reporting style of these articles severely constrain the ability to explore variation in outcomes due to study, patient, or prosthesis characteristics and restrict their generalizability.