Association between plate position and hinge fracture after high tibial osteotomy

Medial open-wedge high tibial osteotomy (MOWHTO) can lead to lateral hinge fractures, which may lead to serious complications, such as delayed union or nonunion of the medial opening gap. The purpose was to investigate whether plate position influences the occurrence of hinge fracture in MOWHTO. We enrolled 51 patients (51 knees) undergoing MOWHTO for primary medial osteoarthritis. Plate position was quantified by measuring the plate angle, defined as the angle between a line connecting the two ends of the plate and a line tangent to the posterior cortical surface. Patients were divided into two groups according to the presence or absence of lateral hinge fracture. The mean plate angle was significantly smaller in the hinge fracture group (36.4° ± 5.6°) than in the non-fracture group (44.7° ± 7.4°, P < 0.001). Multivariable logistic regression analysis showed that plate angle alone served as the significant predictor of lateral hinge fracture occurrence (Adjusted odds ratio = 0.837, P < 0.001) Patients in the hinge fracture group exhibited a plate angle approximately 8.2° smaller than that observed in the group without fracture, suggesting that anterior placement on the proximal tibia is associated with an increased likelihood of hinge fracture.