Effect of Kidney Function on Outcomes Following Ankle Fracture ORIF

Submission Type: Ankle Fractures Research Type: Level 3 - Retrospective cohort study, Case-control study, Meta-analysis of Level 3 studies Introduction/Purpose: Estimated glomerular filtration rate (eGFR) is commonly used as a preoperative evaluation of kidney function in patients undergoing surgery. To date, there is a paucity of literature investigating the effect of eGFr on outcomes following ankle fracture open reduction and internal fixation (ORIF). As such, this study aims to analyze the effect of kidney function, as measured by eGFR, on short-term adverse outcomes following ankle fracture ORIF procedures. Methods: The American College of Surgeons (ACS) National Surgical Quality Improvement Program (NSQIP) database was queried from 2005 – 2019 to identify patients undergoing ankle ORIF. After exclusion of patients missing data for age, race, gender, preoperative creatinine, or with eGFR greater than 3 standard deviations from the mean (91.1 mL/min/1.73 m2), 21,815 patients met criteria for the study. Patients were grouped by eGFR into cohorts: ESRD ( < 15 [1.49%]), moderate to severe kidney function loss (15-60 [17.73%]), mild kidney function loss (60-90 [33.76%]), and normal kidney function (>90 [47.01%]). Results: Nearly half of patients were found to have “normal” eGFR criteria of greater than 90mL/min/1.73m2. As eGFR decreased, indicating poorer kidney function, patient age (p <.001), BMI, rate of female sex, and rate of numerous comorbidities statistically significantly increased. Multivariate regression to control for differences in demographics and comorbidities found that as compared to a normal eGFR, patients with ESRD or moderate to severe loss of kidney function had statistically significantly predicted increased risk of any complication (ESRD: Odds Ratio [OR]=1.505)(15-60:1.261), reoperation (ESRD: OR=1.706)(15-60: 1.314), and readmission (ESRD: OR=1.890)(15-60: 1.649). Conclusion: Low eGFR values, indicative of kidney injury or disease, are significantly predictive of increased risk of postoperative complications, reoperation, and readmission for patients undergoing ankle fracture ORIF. This finding should be considered by surgeons and patients when considering ankle ORIF for patients with decreased kidney function.