The Effect of ASA Score on Total Ankle Arthroplasty

Abstract

Category: Ankle; Other Introduction/Purpose: The American Society of Anesthesiologist (ASA) physical status classification system serves as a useful measure of patient comorbidities. Multiple studies have found an increased risk of readmission in patients undergoing total knee or hip arthroplasty with elevated ASA scores. There is a paucity of literature investigating the association of ASA score and postoperative outcomes following total ankle arthroplasty (TAA). Thus, this study seeks to evaluate the relationship between ASA score and postoperative outcomes following TAA. Methods: The American College of Surgeons (ACS) National Surgical Quality Improvement Program (NSQIP) database was queried from 2007-2020 to identify 2210 TAA patients. Patients were stratified based on preoperative ASA score, 1-normal healthy patient (n=101), 2-mild systemic disease (n=1228), 3-severe systemic disease (n=855), 4-severe, life-threatening systemic disease (n=26). Demographics, medical comorbidities, concomitant procedures, hospital length of stay (LOS), and 30-day complication, readmission, and reoperation rates were compared between groups. The cohort was predominantly male (54.0%) and mean patient age was 63.99 (range 19-87) years with a mean BMI of 31.01 (range 17.14-57.78) m/kg2. Results: Patients with an ASA score ≥3 were significantly older (≤2 =62.78, ≥3 =65.81%; p<.001), with higher BMI (≤2 =29.72, ≥3=32.97; p<.001). 2210 patients were discharged following TAA, with 37 readmitted within 30 days following surgery. There was no statistically significant difference in readmission or reoperation rate based on ASA score. (Table 1) The average LOS following TAA was 1.81 (range 0-28) days, and increased ASA score was statistically significantly associated with longer length of stay (≤2=1.69 days, ≥3 =1.98 days; p<.001). Patients with ASA score ≥3 were discharged home at a significantly lower rate than those with lower ASA scores (≤2 =95.3%, ≥3 =87.4%; p<.001). There was no statistically significant difference in postoperative complication rates within 30 days of surgery. Conclusion: Higher ASA score was statically significantly associated with increased length of stay and non-home discharge disposition. These findings are valuable for physicians and patients to consider prior to TAA given the increased utilization of resources and cost associated with higher ASA scores.