Doc – When Can I Drive?

The hospital stay for hip joint replacement patients has steadily decreased from a week to a couple of days or even same-day surgery. But, the time between the hip surgery and when patients can get back in their cars and drive again has not changed—until now.

Ed Susman, writing for Med Page Today, reports that when doctors use minimally invasive surgical techniques their patients can safely return to driving two weeks earlier than current recommendations allow. Surgeons have long been aware that patients who undergo total hip replacements have decreased reaction time for a period following their surgery, making it unsafe for them to drive in the immediate post-operative period. Six weeks has been the standard surgeons’ recommendation for waiting before resuming driving.

Geoffrey Westrich, M.D., director of research at the Hospital for Special Surgery, New York, decided to test that recommendation with a stimulator similar to those used in video games. The simulator showed that patients two and three weeks out from their hip surgery had not recovered their pre-operation driving skills. They were not safe drivers.

By four weeks following their surgery he found that 31 hip surgery patients improved their pre-operation driving reaction time from an average of 0.751 seconds to an average of 0.716 seconds by four weeks after their surgery.

Westrich then wondered if the kind of joint replacement surgery the patients experienced made a difference in their post-surgery reaction times. To find out, he and his associates enrolled 90 patients who had had hip replacement arthroplasty in a study and tested their reaction times both before and following their operations.

They divided the patients into three groups and tested them at two weeks, three weeks and four weeks following their surgery. The researchers recorded the amount of time it took for the subjects to switch from the gas pedal to the brake pedal after a stop sign appeared.

The 31 patients in the two-weeks-following-surgery group had an average reaction time of 0.862, which was more than their pre-operation time of 0.793 seconds.

The 28 patients in the three week test group had an average reaction time of 0.808 seconds after surgery compared with 0.798 seconds before surgery.

The 28 patients in the three week test group demonstrated an average reaction time of 0.808 seconds after surgery compared with 0.798 before surgery.

Susman quoted Westrich as saying, “We defined a return to safe driving reaction time as a return to a driving reaction time that is either the same as or better than the preoperative driving time. Observing reaction times revealed that at 2 and 3 weeks after surgery patients have not made a full recovery to their respective baseline reaction time and generally are not ready to drive.”

But by four weeks, the patients not only had recovered their reaction times but had improved them. “Therefore, ” said the researchers, ” they can be cleared to drive.”