Glucose Lability and Complications in Diabetic Ankle Fractures

Introduction/Purpose: Rotational ankle fractures in diabetics have long posed difficult clinical challenges, with several observational studies noting increased risk of complications and amputation following treatment of unstable ankle fractures in diabetics. Several treatment options exist, including non-operative management, external fixation, open reduction internal fixation, staged fixation, and fusion. Hemoglobin A1C produces a mean blood glucose level over a three-month period. There is mounting evidence that glucose variability may be an alternative predictor of complication profile in non-orthopedic procedures, as well as in the total joint arthroplasty literature. The purpose of this investigation is to retrospectively analyze complication rates for diabetics with rotational ankle fractures at a single institution and assess their association with both the hemoglobin A1C and glucose variability. Methods: After obtaining Institutional Review Board approval, all patients from 2015-2022 with a diagnosis of diabetes and ankle fracture were retrospectively identified based on ICD-9/ICD-10 codes. These charts were manually reviewed to determine fracture classification and treatment. For operatively and non-operatively managed ankle fractures, the patient’s hemoglobin A1C was recorded when available within 3 months of the date of injury. Glucose variability was calculated using a coefficient of variation. Results: Two-hundred patients were included for analysis, of which 29% (n=58) were treated non-operatively. The majority of surgically treated patients underwent acute ORIF (58%, n=116). 8.5% were treated with staged fixation, 3.5% with acute hindfoot fusion, and 1% with external fixation alone. The overall complication rate was 27.5% (n=55). There were no statistically significant differences in both A1C (7.81 +/- 1.89 vs 7.73 +/- 1.96) and glucose variability, as measured by the covariance of variation (0.23 +/- 0.15 vs 0.20 +/- 0.13) in patients who did and did not experience postoperative complications. Higher glucose variability did trend towards predicting complications, though not in a statistically significant fashion (OR=1.57, p=0.35). Conclusion: Ankle fractures in patients with diabetes pose a challenge for orthopedic surgeons, as evidenced by the high medical and surgical complication rate observed in this study and others. No statistical significance was found between higher A1C and complication rate or between glucose variability and complication rate. Further investigation on the impact of glucose variability on complication rates in a larger cohort of this patient population is warranted. Univariable logistic Regression Results for the association of the odds of post-operative complication with patient characteristics.