5-Item Modified Frailty Index Score is Associated with Increased Postoperative Complications Following Ankle Fracture ORIF

Category: Trauma; Ankle Introduction/Purpose: Ankle fractures are among the most common injuries in orthopaedics and often require surgical management to obtain a stable mortice. It is essential to quantify preoperative risk for patients undergoing ankle fracture repair, but a consensus regarding an optimal risk stratification model does not currently exist. The 5-factor modified frailty index (mFI-5) has been found to be an independent predictor of postoperative complications following numerous orthopaedic procedures, but its efficacy has not been evaluated in patients undergoing ankle fracture open reduction and internal fixation (ORIF). This study aims to analyze the effect of preoperative mFI-5 on 30-day complication, readmission, reoperation, and mortality rates following ankle fracture procedures. Methods: The American College of Surgeons (ACS) National Surgical Quality Improvement Program (NSQIP) database was queried from 2005-2019 to identify 44,755 patients undergoing ankle fracture ORIF using Current Procedural Terminology (CPT) codes 27766, 27792, 27814, 27822, and 27823. Patients were stratified into groups based on preoperative mFI-5 scores, which incorporate the presence of chronic obstructive pulmonary disease, pneumonia, congestive heart failure, non-independent functional status, and diabetes into a composite risk index. Demographics, hospital length of stay (LOS), and 30-day complication, surgical site infection (SSI), Clavien-Dindo grade IV (CDIV) complication, readmission, reoperation, and mortality rates were compared between groups. The cohort was predominantly male (59.0%) and the mean age was 49.52 (range, 16-89) years. Preoperative mFI-5 was also used as a categorical variable when analyzing postoperative outcomes. Results: A total of 44,838 patients met criteria for inclusion, with the majority of patients having an mFI-5 score of 0 (mFI-5:0=65.1%, mFI-5:1=27.0%, mFI-5:2=6.5%, mFI-5:3=1.1%, mFI-5:4=0.2%). The mFI-5 score was a predictor of serious medical complications (myocardial infarction, sepsis, pulmonary embolism, postoperative dialysis, prolonged ventilator requirement, SSI, blood transfusion, DVT/thrombophlebitis, and pneumonia), adverse discharge to a facility, readmission, and reoperation. (Table 1) Mortality was strongly predicted by mFI-5 with the risk more than tripling for each point increase in mFI-5 score (odds ratio (OR)=3.639, 95% CI= 3.038-4.360). Lastly, LOS was also found to increase with mFI-5 with the average length of stay increasing by 1.44 days per increase in mFI-5 score. Conclusion: Our results indicate that mFI-5 score is useful as a predictive measure for postoperative complications, adverse discharge, readmission, reoperation, mortality, and length of stay for patients undergoing ankle ORIF. The variables considered by mFI-5 are easily obtained through a patient history, making this scale a practical measure to identify patients at increased risk for postoperative outcomes.