After Hip Replacement Surgery – “Video Game” Tests Driving Skills
Study launched to test driving reaction time to see when patients can safely get back behind the wheel
(New York, NY. December 12, 2011.) After hip replacement, many patients are anxious to resume driving, and a new study seeks to find out when it would be safe for them to get back behind the wheel. Dr. Geoffrey Westrich, co-director of joint replacement research at Hospital for Special Surgery in Manhattan, is using a computerized driving simulator to test driving reaction time after the surgery.
“One of the most common questions patients ask after hip replacement is when they can start driving again, and we really don’t have a good answer,” said Dr. Westrich, who got the idea for the study while watching his children play video games. But the driving simulator is a lot more complicated than a Wii game. “It’s a very sophisticated machine made by a company that makes driving simulators for the automobile industry,” Dr. Westrich said.
Patients exhibit decreased reaction time after hip replacement surgery, making it unsafe to drive in the immediate post-operative period. Most doctors recommend patients wait about six weeks before they resume driving, but many don’t want to wait that long.
“Over the past five or 10 years, we’ve seen advances such as minimally invasive hip replacement and newer implants that are advantageous to patients. Our study seeks to obtain good, objective data to determine if it would be safe for people to return to driving sooner,” Dr. Westrich said.
Patients participating in the study take the driving test prior to having surgery. They are then randomly selected to repeat the test TWO, THREE or FOUR weeks after hip replacement. At the end of the study, researchers will analyze the findings to determine if it is feasible for patients to resume driving earlier than current recommendations.
Investigators define a safe driving reaction time after hip replacement as a return to a driving reaction time that is either the same or shorter than that measured before the surgery.
Reaction time is measured by the computerized driving simulator. The reaction timer, which is equipped with an accelerator and brake pedal, simulates driving. Patients are instructed to place their foot on the accelerator, which activates a green light, and to keep their foot on the accelerator until a Stop sign appears. When the Stop sign pops up, they’re supposed to move their foot to the brake pedal.
The amount of time it takes for the subject to switch from the gas to the brake pedal is measured by the machine. Patients practice this simulation three times and are then given five test trials.
Patricia Lynch, a nurse from Brooklyn, was happy to participate after hip replacement. “I thought the study was an excellent idea. As a nurse, I believe in evidence-based practice and feel doctors should know and study things in order to make the right recommendations to patients.”
Right before the operation and then just two weeks after Dr. Westrich performed a minimally invasive hip replacement, Mrs. Lynch took the driving simulator test. In terms of her reaction time, she feels she did as well two weeks after surgery as she did before the operation. She is anxious to return to driving free of the pain that prevented her from going more than a few miles before hip replacement.
In addition to determining when it is safe for patients to resume driving, the study will attempt to answer the following questions:
- How does age affect driving reaction time after hip replacement?
- Is there a difference in driving reaction time between genders?
The study seeks to enroll at least 100 patients under age 80 who have a right hip replacement at Hospital for Special Surgery. About 25 patients have participated to date.
Contact: Robin Frank