Lower-extremity function for driving an automobile after operative treatment of ankle fracture.

Background: The purpose of this study was to determine when patients recover the ability to safely operate the brakes of an automobile following operative repair of an ankle fracture. Methods: A computerized driving simulator was developed and tested. Eleven healthy volunteers were tested once to establish normal mean values (Group I), and a group of thirty-one volunteers with a fracture of the right ankle were tested at six, nine, and twelve weeks following operative repair (Group II). The subjects were tested with a series of driving scenarios (city, suburban, and highway). Scores on the Short Form Musculoskeletal Assessment were recorded at six, nine, and twelve weeks and were compared with the results of the driving test. We investigated the effect of the time of the visit and of the testing condition on the braking times. Results: The total braking time was 1079 msec for Group I and 1330, 1172, and 1160 msec for Group II at six, nine, and twelve weeks, respectively, postoperatively (p = 0.0094). The total braking time consistently improved for each of the driving scenarios at each successive data point (p = 0.05). The increase in the total braking time at six weeks meant an increase in the distance traveled by the automobile before braking of 22 ft (6.7 m) at 60 mph (96.6 km/hr), and the increase at nine weeks meant an increase of 8 ft (2.4 m) at 60 mph. The functional outcome improved at each successive visit, although no significant association was found between the functional scores and normalization of total braking time. Conclusion: By nine weeks, the total braking time of patients who have undergone fixation of a displaced right ankle fracture returns to the normal, baseline value.