Driving Reaction Time After Left Sided Foot and Ankle Procedures

Abstract

Category: Ankle Introduction/Purpose: Previous authors have considered braking times using computer simulators in a effort to evaluate patient safety in returning to drive. Authors have considered brake response times after first metatarsal osteotomy, ankle fusion, ankle fracture as well as anterior cruciate ligament reconstruction and hip and knee arthroplasty. Brake reaction time (BRT), a commonly used parameter, is defined as time from a “stop” stimulus until a brake is depressed. Previous work suggested that a BRT of 0.47 seconds (s) was average for a healthy population and that a BRT > 0.7 s is potentially hazardous. To our knowledge, there is no previous study of left sided foot and ankle procedures and how these procedures may affect BRT and driving safety. The present pilot study aimed to evaluate postoperative BRT in patients at our institution who had undergone left sided foot and ankle procedures. Methods: Seventeen patients were enrolled in the study: 7 underwent ankle arthroscopy, 4 flatfoot reconstruction, 3 ankle arthroplasty, 2 ankle fusion, and 1 cavovarus foot reconstruction. Participants had their surgical procedures performed at a range of 6 weeks to 6 months prior to study enrollment. We utilized a standard software and hardware setup which included a steering wheel, gas and brake pedal and desktop computer which displayed the driving simulation (The Stationary Simple Reaction Timer, Vericom Computers, Inc, Rogers, MN). All participants had left sided surgery and had their right lower extremity tested in the driving simulation. All participants completed 4 driving simulations which were then averaged. Data was analyzed in two groups, those who underwent only ankle arthroscopy and those who underwent an open procedure (Flatfoot reconstruction, ankle arthroplasty, ankle fusion, cavovarus foot reconstruction). BRT was defined as the time from stop stimulus until brake depression of 5%. Results: Average BRT in patients undergoing ankle arthroscopy was 0.66 s (SD 0.06 s). Average BRT in patients undergoing any open procedure was 0.65 s (SD 0.08 s). In patients undergoing ankle arthroscopy, average BRT at 6 weeks was 0.65 s (N=2), 0.64 s at 3 months (N=3), and 0.69 s at 6 months (N=2). In patients undergoing an open procedure, average BRT at 6 weeks was 0.62 s (N=3), 0.65 s at 3 months (N=5), and 0.69 s at 6 months (N=2). Conclusion: We present driving simulation brake reaction time on patients undergoing common, left sided foot and ankle procedures at our institution. In both arthroscopic and open procedure populations BRT is greater than previously described healthy patient populations and is slightly below a previously defined “hazardous” cutoff of 0.7 s.