Incidence of Complications and Risk Factors for Nonunion After Ankle Fracture in Diabetes Mellitus

BACKGROUND: To evaluate complications and risk factors for nonunion in patients with diabetes after ankle fracture. METHODS: We conducted a retrospective study of 139 patients with diabetes and ankle fractures followed for 1 year. We evaluated the incidence of wounds, infections, nonunions, Charcot's arthropathy, and amputations. We determined Fracture severity (unimalleolar, bimalleolar, trimalleolar), nonunion, and Charcot's arthropathy from radiographs. Nonunion was defined as a fracture that did not heal within 6 months of fracture. Analysis of variance was used to compare continuous variables, and χ2 tests to compare dichotomous variables, with α = 0.05. Logistic regression was performed with a binary variable representing nonunions as the dependent variable. RESULTS: Complications were common: nonunion (24.5%), Charcot's arthropathy (7.9%), wounds (5.2%), wound site infection (17.3%), and leg amputation (2.2%). Patients with nonunions were more likely to be male (55.9% versus 29.5%; P = .005), have sensory neuropathy (76.5% versus 32.4%; P < .001), have end-stage renal disease (17.6% versus 2.9%; P < .001), and use insulin (73.5% versus 40.1%; P < .001), β-blockers (58.8% versus 39.0%; P = .049), and corticosteroids (26.5% versus 9.5%; P = .02). Among patients with nonunion, there was an increased risk of wounds (odds ratio [OR], 3.3; 95% confidence interval [CI], 1.46-7.73), infection (OR, 2.04; 95% CI, 0.72-5.61), amputation (OR, 7.74; 95% CI, 1.01-100.23), and long-term bracing (OR, 9.51; 95% CI, 3.8-23.8). In the logistic regression analysis, four factors were associated with fracture nonunion: dialysis (OR, 7.7; 95% CI, 1.7-35.2), insulin use (OR, 3.3; 95% CI, 1.5-7.4), corticosteroid use (OR, 4.9; 95% CI, 1.4-18.0), and ankle fracture severity (bimalleolar or trimalleolar fracture) (OR, 2.5; 95% CI, 1.1-5.4). CONCLUSIONS: These results demonstrate risk factors for nonunions: dialysis, insulin use, and fracture severity after ankle fracture in patients with diabetes.