SLR - July 2019 - Samuel G. Kellner

Brake Reaction Time After Ankle and Subtalar Arthroscopy

Reference: Sittapairoj T, Anthony C, Rungprai C, Gao Y, Barg A, Phisitkul P. Brake Reaction Time After Ankle and Subtalar Arthroscopy. Arthroscopy: The Journal of Arthroscopic and Related Surgery. Dec 2017; 33(12), 2231-2237.

Scientific Literature Review

Reviewed By: Samuel G. Kellner, DPM
Residency Program: MetroWest Medical Center – Framingham, MA

Podiatric Relevance: Arthroscopy of the foot and ankle is increasingly popular as a diagnostic and treatment modality of various pathologies, including arthritis, impingement syndromes, and osteochondral lesions. As techniques and equipment technology advances, surgeons and patients alike will opt for this minimally invasive approach as evidence supports excellent outcomes. One of the most important discussions in the surgical evaluation is of the post-operative protocols, and this study aims to establish a timeline for a safe return to driving activity.

Methods: This is an IRB-approved study of 17 patients who underwent right ankle or subtalar arthroscopy through a standard approach. A control group of 19 patients was also studied and was matched to age and sex of the experimental group. Inclusion criteria consisted of patients over 18 years old with a valid driver’s license and who regularly drove automatic transmission vehicles. Exclusion criteria was of medical problems that prohibited safe driving or non-weightbearing status after surgery. The patients underwent a simulated driving experience with two practice trials and four test trials, where the participants were instructed to drive as they normally would at a selected speed, and to press the brake pedal hard and rapidly when a red light appeared on the screen. The brake reaction time (BRT) was defined as the time from the red light presentation until 5% percent of the brake pedal depression. Of the four test trials, the fastest and slowest were eliminated and the average of the two remaining trials were calculated.

Results: Of the 17 patients, 10 were diagnosed with OCDs, three with anterior ankle impingement, 3 with posterior ankle impingement, and one with anterior and posterior ankle impingement. In the experimental group, the average pre-operative BRT was 0.59 +/- 0.05 seconds compared with 0.55 +/- 0.05 seconds in the control group. The average 2-week post-operative BRT in the experimental group was 0.57 +/- 0.05 seconds, finding no statistical significant difference from the pre-operative or control group averages.

Conclusions: This study finds emergency BRT in patients who underwent right sided ankle or subtalar arthroscopy improves by two weeks after surgery. This is sooner than most suggested cutoffs for safe driving, however to determine the safest time to drive goes beyond just the BRT. The study mentions other factors such as age, driving experience, driving speed, task complexity, active medications, and environmental factors, which are variables not included here. However, BRT was decided as the most important variable in driving, especially in emergency situations. The Federal Highway Administration has established 0.70 seconds as the maximum cutoff time for BRT, and all participants in this study were able to react in sufficient time two weeks post-operatively. This study does not address return to driving earlier than two weeks which some patients may be able to do.

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