High Tibial Osteotomy Survivorship: A Population-Based Study

Background: High tibial osteotomy (HTO) was developed to treat early medial compartment osteoarthritis in varus knees. Purpose: To evaluate the midterm and long-term outcomes of HTO in a large population-based cohort of patients. Study Design: Case-control study; Level of evidence, 3. Methods: Data from the California Office of Statewide Health Planning and Development were used to identify patients undergoing HTO from 2000 to 2014. Patients with infectious arthritis, rheumatological disease, congenital deformities, malignancy, concurrent arthroplasty, or skeletal trauma were excluded. Demographic information was assessed for every patient. Failure was defined as conversion to total or unicompartmental knee arthroplasty. Differences between patients requiring arthroplasty and those who did not were identified using univariate analysis. Multivariate analysis was performed, and Kaplan-Meier survivorship estimates for 5- and 10-year survival were computed. Results: A total of 1576 procedures were identified between 2000 and 2014; of these, 358 procedures were converted to arthroplasty within 10 years. Patients who went on to arthroplasty after HTO were older (48.23 +/- 6.76 vs 42.66 +/- 9.80 years, respectively; P < .001), had a higher incidence of hypertension (25.42% vs 17.82%, respectively; P = .001), and had a higher likelihood of having >= 1 comorbidity (38.0% vs 31.4%, respectively; P = .044). Patients were 8% more likely to require arthroplasty for each additional year in age (relative risk [RR], 1.08). Female patients were also at an increased risk of conversion to arthroplasty compared with male patients (RR, 1.38). Survivorship at 5 and 10 years was 80% and 56%, respectively, and the median time to failure was 5.1 years. Conclusion: HTO may provide long-term survival in select patients. Careful consideration should be given to patient age, sex, and osteoarthritis of the knee when selecting patients for this procedure.