High Tibial Osteotomy for Medial Compartment Knee Osteoarthritis A Randomized Trial With Parallel Preference Arm

Background: Medial opening wedge high tibial osteotomy (HTO) is a limb realignment surgery that aims to preserve joint structure and improve clinical outcomes by redistributing ambulatory loads on the knee among patients with knee osteoarthritis and varus alignment. Objective: To evaluate the efficacy of medial opening wedge HTO. Design: Single-center, open-label, assessor-blinded randomized trial with a parallel preference arm. (ClinicalTrials.gov: NCT02003976) Setting: Tertiary care center. Participants: 145 adults with varus alignment and symptomatic knee osteoarthritis primarily involving the medial compartment. Intervention: Nonsurgical management plus HTO compared with nonsurgical management alone (control), which included supervised therapeutic exercise for 3 months, nutrition counseling, and acetaminophen or nonsteroidal anti-inflammatory drugs as needed. Measurements: The primary outcome was 2-year change in medial tibiofemoral articular cartilage thickness, measured on masked 3-Tesla magnetic resonance images, with a 6.3% loss considered the minimal clinically important difference (MCID). A key secondary outcome was change in the total Knee Injury and Osteoarthritis Outcome Score (KOOS; range, 0 to 100; MCID, 10 points). Results: A total of 59 of 71 participants (83%; 30 HTO, 29 control) in the randomized arm and 65 of 74 (88%; 36 HTO, 29 control) in the preference arm were assessed at baseline and 2 years of follow-up. In the randomized arm, the mean 2-year change in medial tibiofemoral articular cartilage thickness was -0.07 mm in the HTO group (a loss of 2%) and -0.25 mm in the control group (a loss of 9%), for a mean between-group difference of 0.18 mm (95% CI, 0.18 to 0.19 mm). The change in total KOOS was 24.95 points in the HTO group and 9.06 points in the control group (mean difference, 15.89 points [CI, 8.94 to 22.84 points]). These outcomes also favored HTO in the preference arm. Limitation: Single-center study. Conclusion: These results support use of medial opening wedge HTO to slow progression of structural joint damage and improve clinical outcomes among patients with medial compartment knee osteoarthritis and varus alignment.