Association of Clinical Findings With Complications in the Cubitus Varus Deformity After Supracondylar Fracture.

Introduction: Cubitus varus deformity is primarily a cosmetic complaint that causes some early and late complications. However, no studies have reported the cubitus varus deformity regarding the frequency of complications, relationship to the degree of deformity, and period from the occurrence of the initial injury.

Methods: Overall, 83 patients with cubitus varus deformity were examined. The differences in the humerus-elbow-wrist angle (∆HEW-A), tilting angle (∆TA), and internal rotation angle (∆IRA) between the affected and normal sides were measured to determine varus and extension and internal rotation deformity. The period from the occurrence of the initial injury to the evaluation date was also investigated. Multivariate logistic regression analysis was conducted to identify the explanatory variables (period, ∆HEW-A, ∆TA, and ∆IRA) independently associated with complication events. Receiver-operating characteristic curve analysis was also conducted to predict the risk of events.

Results: ∆HEW-A was independently associated with the risk of cosmetic complaint (odds ratio [OR], 1.171; 95% confidence interval [95% CI], 1.056 to 1.336) and instability (OR, 1.111; 95% CI, 1.028 to 1.200). ∆TA was independently associated with the risk of limited elbow motion (OR, 1.176; 95% CI, 1.077 to 1.285) and sports disability (OR, 0.892; 95% CI, 0.836 to 0.952). The period from the occurrence of the initial injury was independently associated with risk of pain (OR, 1.063; 95% CI, 1.019 to 1.108), ulnar nerve neuropathy (OR, 1.065; 95% CI, 1.011 to 1.125), and osteoarthritis (OR, 1.188; 95% CI, 1.098 to 1.286). The receiver-operating characteristic curve analysis revealed the optimal cutoffs of 20° and 27° for ∆HEW-A to predict cosmetic complaint and instability; of 25° for ∆TA to predict limited elbow motion; and of 8.8, 8.0, and 16.0 years for the period to predict pain, ulnar nerve neuropathy, and osteoarthritis, respectively.

Discussion: The treatment of cubitus varus deformity should be determined because a residual deformity >20° of varus and 25° of extension could develop risk of complications over time.