Most Readmissions Following Ankle Open Reduction Internal Fixation are Unrelated to Surgical Site Issues

Abstract

Category: Trauma Introduction/Purpose: Ankle fractures are commonly-sustained injuries, and frequently require open reduction internal fixation (ORIF). It is generally a safe and effective surgical procedure, however, as quality-based reimbursement models become increasingly affected by readmissions within thirty days, it is important to determine causes and risk factors for patients to be readmitted after discharge. Methods: Patients that underwent ORIF for ankle fractures were identified from the prospectively-collected American College of Surgeons National Surgical Quality Improvement Program (NSQIP) database from 2013 to 2014. Baseline demographics, comorbidities, and fracture characteristics (open vs. closed, location of fracture such as lateral malleolus, medial malleolus, bimalleolar, or trimalleolar) were determined. Modified Charlson Comorbidity Index (CCI) was used as a measure of overall comorbidity burden. Rates of thirty-day adverse events and readmissions were determined, as well as the causes for readmission. Multivariable logistic regression analyses were performed to identify risk factors significantly associated with having any adverse events and being readmitted within thirty days of surgery. Results: 5,056 ankle ORIF patients were included. 167 (3.3%) were open fractures. The rate of any postoperative adverse event was 5.2%. There were 127 readmissions, with 116 (91.3%) being unplanned readmissions. Of the 116 unplanned readmissions, 49 (42.2%) were for reasons related to the surgery or surgical site, with the most common causes being deep surgical site/hardware infection (12.9%), superficial site infection (11.2%), and wound disruption (6.9%). Most readmissions were for reasons unrelated to the surgical site (51.7%), including cardiac disorders (8.6%), pulmonary disorders (7.8%), and neurologic/psychiatric disorders (6.9%). With multivariable logistic regression, the strongest risk factors for readmission were history of pulmonary disease (Odds Ratio [OR] 2.29), ASA ≥ 3 (OR 2.28), and open fracture (OR 2.04, all p < 0.05). (Figure 1) Conclusion: Postoperative readmissions following ankle fracture ORIF are important to consider in this era of quality-based hospital reimbursement models. In this cohort of 5,056 ankle ORIF cases, 2.5% of patients were readmitted within thirty days, with 51.7% of all unplanned readmissions due to causes unrelated to the surgery or surgical site. This suggests that close medical follow-up with non-orthopaedic providers may be necessary after discharge. To assist clinicians in preoperative risk stratification, predictors of readmission were history of pulmonary disease, increased ASA class, and open fracture. Higher bundled reimbursements may be justified for cases with these risk factors.