Incidence and risk factors for lateral hinge fractures in medial opening wedge high tibial osteotomy and medial opening wedge distal tibial tuberosity osteotomy.

BACKGROUND: The aims of this study were (1) to compare the incidence of lateral hinge fractures (LHFs) in medial opening-wedge high tibial osteotomy (OWHTO) and medial opening-wedge distal tibial tuberosity osteotomy (DTO), and (2) to investigate the risk factors for LHFs. The incidence of LHFs was hypothesized to be higher in the DTO group than the OWHTO group. The DTO procedure is also a risk factor for LHFs.

METHODS: A total of 167 knees that underwent OWHTO (n = 65) and DTO (n = 102) were subjected to propensity score matching for the comparison of the groups. The matched variables were sex, preoperative hip-knee-ankle (HKA) angle, and preoperative medial proximal tibial angle. Forty-one matched pairs were enrolled for comparative analysis. Logistic regression analysis was performed to investigate risk factors for LHFs.

RESULTS: The incidence of LHFs was not significantly different between the groups (34.1% vs. 26.8%, respectively; p = 0.631). Logistic regression analysis showed that age (odds ratio: 1.074, 95% confidence interval (CI): 1.020-1.131, p = 0.007), BMI (odds ratio: 1.150, 95% CI: 1.049-1.260, p = 0.003), and preoperative HKA angle (odds ratio: 1.150, 95% CI: 1.049-1.260, p = 0.035) were significant risk factors for LHFs. The difference in surgical technique between OWHTO and DTO was not a risk factor for LHFs (p = 0.204).

CONCLUSIONS: The incidence of LHFs is similar in DTOs and OWHTOs, and the DTO procedure is not a risk factor for LHFs.

LEVEL OF EVIDENCE: Level III, retrospective cohort study.