Risk of Revision and Adverse Outcomes Following Partial Knee Replacement and High Tibial Osteotomy for Unicompartmental Knee Osteoarthritis: A Nationwide Cohort Study

Purpose To investigate comparative study for potential associations of adverse outcomes as well as survival rates after high tibial osteotomy (HTO) and unicompartmental knee arthroplasty (UKA). Methods We reviewed the Korean National Health Insurance claims database from January 1, 2007 to May 31, 2019. A total of 90,705 patients aged 30-90 years who were newly treated for HTO or UKA were identified considering their eligibility. We performed four rounds of propensity score matching to reduce imbalance of baseline characteristics, especially disparities among different age groups. Multivariable logistic regression models were used to compare the risk of revision and various unwanted medical problems between HTO and UKA treatment groups after propensity score matching. Results 23,563 matched patients were assigned to each group on the basis of propensity score. HTO showed higher risk of revision than UKA at 5 years, 10 years and the whole observed period (hazard ratio: 1.21, 95% CI 1.10-1.34). Deep vein thromboembolism (0.27, 0.21-0.35), and surgical site infection (0.37, 0.30-0.44) were less likely for HTOs than UKAs. Postoperative admission to intensive care unit was significantly lower with HTO (odds ratio: 0.40, 0.29-0.54) while rehospitalization within 30 days (1.27, 1.16-1.38) and 90 days (1.24, 1.18-1.30) were higher than UKA. Conclusion When choosing the surgical method for unicompartmental knee OA, not only the survival rate, but also the risk of other adverse outcomes should be considered. In particular, attention should be paid to the risk of developing deep vein thromboembolism and surgical site infection.