Driving Reaction Time after Right Knee Anterior Cruciate Ligament Reconstruction

OBJECTIVES: The purpose of the present study was to determine when patients recover the ability to safely operate the brakes of an automobile following a right knee anterior cruciate ligament reconstruction (ACLR). METHODS: A prospective case series of 27 patients who underwent a right knee ACLR, nine with a bone patellar tendon-bone (BPTB) autograft, nine patients who had hamstring (HS) tendon autograft and nine patients who had tibialis anterior (TA) tendon allograft for their reconstructions were tested in a validated computerized driving simulator. At 7-10 days, three weeks, and six weeks post operatively, patients were evaluated with respect to their brake reaction time (BRT), brake travel time (BTT), and total braking time (TBT). Each cohort was then compared with thirty healthy volunteers with similar demographics to establish normative mean values. RESULTS: At 7-10 days post-operatively, all patients had statistically significant differences compared to controls for BRT, BTT, and TBT, regardless of the graft used for the reconstruction. By three weeks post-operatively, those reconstructed with TA allografts demonstrated a return to normal braking parameters with no statistically significant differences compared to controls between BRT, BTT, and TBT, whereas those with BPTB and HS autografts continued to have significant delays in their BTT and TBT with BPTB (p = 0.007, p = 0.009) and HS (p = 0.016, p = 0.015), respectively. By six weeks post-operatively, braking parameters for patients receiving an ACL reconstruction with a hamstring autograft returned to normal values while those treated with a BPTB autograft continued to demonstrate impairment in brake travel time and total braking time compared to controls; however, their brake reaction time had recovered to normative values. CONCLUSION: Patients who underwent a right knee ACL reconstruction with a TA allograft regained normal braking times by three weeks post-operatively and continued to improve through the six week post-operative time point. In contrast, those treated with a BPTB or HS autograft demonstrated impaired ability to operate motor vehicle brakes three weeks following surgery. While at six weeks, the braking ability of patients treated with hamstring autografts normalized, those receiving a BPTB autograft continued to demonstrate limitations in their brake travel time and total braking time. Patients should be counseled appropriately when discussing reconstruction options and when it is safe to resume driving.