Weight Changes after Ankle Fracture Surgery: A Retrospective Cohort Study

Abstract

Background: Recovery from open reduction internal fixation of the ankle frequently involves a decrease in activity level and some limitations in weightbearing. The purpose of this study was to evaluate weight changes during the postoperative period following ankle fracture surgery. Methods: Hospital billing records were retrospectively reviewed to identify all patients who underwent open reduction internal fixation of bimalleolar and trimalleolar ankle fractures at our hospital system between January 1, 2018 and June 30, 2021. Weight data from outpatient encounters coinciding with the 3-month, 6-month, and 1-year postoperative time points were recorded and analyzed. Results: 56 patients had complete weight data. The mean age at surgery was 44.6±16.2 years. There were 27 women and 29 men. At time of surgery, the mean weight was 197.2.3±53.9 lbs and BMI was 30.3±7.1 kg/m2. At 1 year postoperative, the mean weight was 219.2±51.6 lbs and BMI was 33.8±7.0 kg/m2, representing statistically significant increases of 22.0 lbs and 3.4 BMI points compared to preoperative (p=0.0491 and 0.0330, respectively). On subgroup analysis of different preoperative BMI groups (<25, 25-29, 30-34, and ≥35), only those patients with a pre-operative BMI of <25 experienced statistically significant increases in weight and BMI, 27.9 lbs and 4.8 kg/m2 respectively (p=0.029 and p=0.001). Conclusion: This is the first study to evaluate weight changes following ankle fracture. This study showed that at 1 year patients recovering from ankle open reduction internal fixation gain an average of 22 lbs and 3.4 BMI points. Patients with a pre-operative BMI of <25 are subject to statistically significant increases in weight. We recommend monitoring patients’ weight and counseling them on the risks of weight gain. Further research is necessary to better characterize the risk of weight gain following orthopedic surgery. Level of Evidence: 4 (retrospective cohort)