Influence of spine surgery on the ability to perform an emergency stop while driving a car

BACKGROUND: Spinal surgeries have strongly increased in number over the past decade. The question of when it is safe to resume driving is thereby one the most frequently asked questions that patients ask of their treating physician. OBJECTIVE: The aim of this study was to assess braking performance before and after spine surgery. METHODS: Reaction time, foot transfer time (together brake response time [BRT]), and brake force (BF) were evaluated in a drive simulator. A longitudinal patient cohort (n= 27) was tested preoperatively and at the first follow-up. A cross-sectional cohort (n= 27) was tested at > 1 year postoperatively. The values from these groups were compared with a healthy age-matched control group of 24 volunteers. RESULTS: No significant improvement in BRT was seen in lumbar fusion three months postoperatively (p= 0.597); BF was even weaker than it was preoperatively (p= 0.044). In comparison to the control group (median BRT 479 ms), preoperative BRT was already impaired in lumbar fusion patients (median 560 ms), representing an increased braking distance of 2.25 m at 100 km/h. CONCLUSION: Although most patients performed adequately, about one third presented critical braking performance. Risk factors for impaired braking may include scheduled multisegmental fusion surgery, female sex, and pain.