Risk Stratification for Ankle Fracture Complications in Diabetic Patients

Abstract

Category: Diabetes Introduction/Purpose: While diabetes is a well-known risk factor for morbidity following surgical fixation of ankle fractures, it is likely that increased risk is related to specific diabetes-associated comorbidities. Compared to patients with uncomplicated diabetes, patients with complicated diabetes have higher risks of infection, overall complications, and a higher likelihood of needing revision surgery/arthrodesis. This suggests that the presence and severity of specific risk factors may help predict post-operative risks for diabetic ankle fracture patients and help guide treatment decisions. To date, no study has identified specific diabetes-associated factors and comorbidities which can pose an increased risk of complications for diabetic ankle fracture patients. We hypothesized that patients with diabetes-related comorbidities will suffer significantly more major complications following surgery for unstable ankle fractures compared to uncomplicated diabetics. Methods: We retrospectively reviewed all patients with diabetes treated surgically for ankle fracture at a University medical center over a 12-year period, examining patient and fracture characteristics, treatment method, and clinical and laboratory factors associated with complications. Outcome variables include time to union, wound complication, infection, hardware failure, and need for additional surgery following injury. The primary outcome was major complication, defined as the presence of one or more of the following: deep infection (as evidenced by hardware removal or I&D), amputation, malunion or non-union, skin graft, or wound complication (as evidenced by infection or dehiscence). Bivariate analyses and logistic regression were used to examine the relationships between specific complications and various clinical and demographic factors. A p-value of < 0.05 denotes statistical significance. Results: A total of 61 patients met inclusion criteria. Patient characteristics are depicted in Table 1. Bivariate analyses showed that when compared to diabetic patients without complications, patients who experienced major complications had a significantly higher rate of renal disease (p = 0.032) and retinopathy (p = 0.020), and significantly more hospital readmissions (p < 0.001). Factors associated with complications were determined by a logistic regression model. Age, sex, race, tobacco use and HgbA1C were not associated with increased risk of major complications. However, for each 1-unit increase in the Charlson Comorbidity Index (CCI) Score, there was a 40.6% increase in the likelihood of major complication among diabetic patients with ankle fractures (p = 0.025). Conclusion: Patients with diabetes-related comorbidities have a significantly higher risk of experiencing major complications following treatment of unstable ankle fractures. In this cohort, renal disease, retinopathy and higher CCI were found to be significantly associated with major complications. Interestingly, neuropathy, smoking, and HgA1C were not independent predictors of major complications in this cohort. These data will inform a multi-center prospective registry of patients with diabetes and ankle fractures, and ultimately the development of a risk tool to help guide clinical decision-making and post-operative care for diabetic patients at risk of major complication, re-admission, or re-operation following treatment for ankle fractures.