Effect of Travel Time and Distance on Outcomes in Total Ankle Arthroplasty

Abstract

Category: Ankle; Ankle Arthritis Introduction/Purpose: Surgeons who perform a higher volume of total ankle arthroplasty (TAA) are known to have decreased complication rates; evidence shows that low volume centers performing TAA have decreased survivorship when compared with high volume centers. Understanding differences in outcomes for patients traveling different distances for their TAA is important for future patients deciding where to travel for their surgery. No study has previously examined differences in outcomes of patients traveling different distances to a high volume center for their TAA. This study compares preoperative and postoperative PROMIS scores for patients undergoing total ankle arthroplasty who traveled less than and more than 50 miles for their TAA. We hypothesized that there would be no difference in outcome scores based on distance traveled or estimated drive time. Methods: This study is a single center retrospective review of 162 patients undergoing primary total ankle arthroplasty between January 2016 and December 2018. We collected the primary address as listed in the patient’s medical record and used the directions feature on Google Maps to estimate driving mileage and estimated driving time from the patient’s address to the hospital. To analyze the distance patients traveled, patients were divided into two groups: 50 miles traveled (n=71). To analyze the estimated drive time, patients were divided into two groups: 90 minutes (n=85). We collected preoperative and most recent postoperative PROMIS scores for all patients. Differences in most recent post-operative PROMIS scores between distance groups and travel time groups were assessed using multivariable linear regression models, adjusting for the pre-operative score and follow-up time. Results: We found no significant difference in post-operative PROMIS scores between the two groups when analyzed for distance traveled or for estimated travel time after adjustment for pre-operative PROMIS score and follow-up time (Table 1). The average follow-up for all 162 patients was 1.49 years. Power analysis showed that with a sample size of 110 (55 in each group), we had 81% power to detect an effect size of 4. Patients saw an increase in their Physical Function scores and a decrease in their Pain Interference and Pain Intensity scores with postoperative scores better than population means (Table 1). Overall complication rate for the 50 miles group had an overall complication rate of 24.0%, 9.9% required surgery. Conclusion: Patients traveling further distances to a high volume orthopedic specialty hospital for their total ankle arthroplasty do not have different clinical outcomes than patients traveling shorter distances. This is particularly important for patients deciding where to have their total ankle arthroplasty surgery. Patients who travel further have the opportunity to be treated at a local academic center; however our results show that outcomes do not change when traveling further for total ankle arthroplasty.