High Tibial Osteotomy for Knee Osteoarthritis with Genu Varum: A Retrospective, Observational Study

<b>Background:</b> High tibial osteotomy (HTO) is a joint-preserving alternative for patients with medial compartment knee osteoarthritis (KOA), although its use has declined in recent decades in favor of total knee arthroplasty (TKA). This study aimed to evaluate HTO outcomes in patients treated at a tertiary center over the past decade. <b>Methods:</b> We conducted a single-center, retrospective, observational cohort study of patients with medial femorotibial KOA and genu varum who underwent HTO. Failure was defined as conversion to TKA. A comparative analysis regarding HTO survival was conducted with preoperative variables and KOA stages in the follow-ups up to 5 years. Univariate and multivariate Cox regression models were built to assess their effect on HTO survival time. The Kaplan-Meier method was used to estimate overall and subgroup survival. Disease progression over time was evaluated with the Bhapkar test. In all cases, <i>p</i> < 0.05 was considered statistically significant. <b>Results:</b> HTO was successful in 74.6% of the 63 patients. Age was significantly higher in the failure group (<i>p</i> = 0.006), and each additional year increased the hazard of failure by 8% (95% CI, 1.01-1.16, <i>p</i> = 0.033), although this significance was lost in multivariate analysis (<i>p</i> = 0.104). Kaplan-Meier estimated survival was 76.7% at 5 years, with a median survival time of 10.1 years. KOA stage progression was significant 5 years after HTO (<i>p</i> < 0.001). <b>Conclusions:</b> HTO demonstrated 76.7% survival at 5 years, with radiographic KOA progression over time. The association between age and failure was not maintained after multivariable adjustment.