Increased Rates of Readmission, Reoperation, and Mortality Following Open Reduction and Internal Fixation of Ankle Fractures Are Associated with Diabetes Mellitus

Abstract

Category: Ankle Introduction/Purpose: Ankle fractures are amongst the most common type of fracture injury in adults with an annual incidence of 187 fractures per 100,000 people in the United States. Previous groups have shown that diabetes mellitus (DM) is associated with a myriad of complications – including infection, malunion, and impaired wound healing – following open reduction internal fixation (ORIF) surgery for ankle fractures. However, to our knowledge there has not been a large-scale nationwide study on the rate of readmission, reoperation, and mortality associated with DM. The purpose of this study was to calculate the increased risk and odds ratios for 30-day postoperative readmission, reoperation, and mortality after ankle fracture ORIF. Methods: Patients who underwent ORIF for ankle fractures from 2006 to 2015 were identified in the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database using Current Procedural Terminology codes. Median values along with 25th to 75th interquartile ranges (IQRs) were used to describe continuous variables and frequency (%) was used to describe categorical variables. Patient demographic factors along with 30-day postoperative outcomes were compared between those who had DM and those who did not have DM using the Mann-Whitney test or?2 test. 30-day postoperative unplanned readmission, unplanned reoperation, and mortality rates were compared in 2,044 patients with DM and 15,420 patients without DM. Crude odds ratios (OR) and adjusted ORs controlling for age differences were calculated for each parameter with a 95% confidence interval (CI). All statistical analyses were performed with a significance level of 0.05. Results: Patient factors and pre-operative laboratory statistics are summarized in Figure 1D, and the distribution of ankle fractures types are shown in Figure1A&B. Comparing patients with DM vs without DM, the rate of readmission was 4.35% vs 1.50%, rate of reoperation was 2.30% vs 0.75%, and rate of mortality was 0.73% vs 0.21%. As shown in Figure 1C, we found that patients with DM had a 2.66 times increased risk of readmission (CI: 1.99-3.52, p = 0.0001), 2.76 increased risk of reoperation (CI: 1.91-3.92, p = 0.0001), and a 2.34 increased risk of mortality (CI: 1.19-4.44, p = 0.0377). Interestingly, we also found a 22.06 increased risk of amputation (CI: 3.29-344.8, p = 0.0063) though the rate of amputation in both groups was very small. Conclusion: In this large-scale retrospective study we showed that the presence of diabetes mellitus significantly increases the risk of unplanned readmission, unplanned reoperation, and mortality within 30 days after ankle fracture ORIF surgery. Thus, patients with diabetes that require ORIF ankle surgery should be informed of their increased risk of complications and extra precautions should be taken to minimize risk. Further research in optimization of perioperative care for diabetic patients is crucial to reducing rates of complication. Large clinical databases such as ACS-NSQIP should endeavor to collect more parameters on diabetic patients to facilitate these studies.