Dr. Prakash Jayabalan has long pondered why there are no more non-operative treatment options available for patients with knee osteoarthritis (OA), particularly because it is the most common cause of disability in the United States.
“Doctors perform about 1 million surgical knee replacements every year,” he said. “Of course, some of these people need surgery. However, I have always thought that many patients with OA undergo knee replacements much earlier than necessary in life. “
Dr. Jayabalan is the chief physician-scientist of the Nancy W. Knowles Strength + Endurance Lab at Shirley Ryan AbilityLab and assistant professor of physical medicine and rehabilitation at Northwestern University Feinberg School of Medicine.
The question – how to help knee OA patients feel better without surgery – led to two research studies she conducts at Shirley Ryan AbilityLab. One is a new test to identify OA first. And the other is the new use of equipment to help OA patients reap the full benefits of pain-free exercise.
Early identification of knee OA
Staying active is the best way for a patient to prevent OA from getting worse. However, one of the biggest challenges of current knee osteoarthritis treatment practices is that diagnosis typically only occurs after a patient has such severe pain that activity is difficult.
“Right now, I can diagnose patients with knee OA using an X-ray and send them for physical therapy, pain management, and possibly injections,” said Dr. Jayabalan. “However, at that point, OA is already at the bottom of the line. I have nothing to prescribe that prevents its progression ”.
To help doctors diagnose knee OA much earlier, Dr. Jayabalan and his lab team are developing a new protocol that they describe as a “cartilage stress test.”
“We have the patient exercise to stress the joints, and then we measure the body’s responses to that stress by looking at blood-based or synovial biomarkers,” he said.
The design of the cartilage stress test is based on two new aspects to measure the metabolic status of the joints. First, it uses a real-time approach. Dr Jayabalan’s team draws blood at periodic intervals using an IV as the patient walks on the treadmill, instead of relying on blood drawn before and after the assessment.
Second, the test uses a special treadmill that provides a mediolateral incline of up to 10 degrees. This angle creates individualized stress loads on each joint.
This new protocol could lead to individualized treatment plans for patients at risk for early OA, such as after anterior cruciate ligament (ACL) reconstruction, while still relatively healthy, years before their joints start to ache. Ideally, early surgery will delay or even eliminate the need for joint replacements.
“We typically tell patients to walk 30 minutes a day, five times a week,” he said. “My goal is to identify an optimal prescription for each patient that can prevent disease progression. With an early diagnosis, we could prescribe an individualized preventive exercise program ”.
Remove the load
For patients with joint pain caused by advanced knee OA, an exercise prescription that includes even the simplest activities, such as walking for 30 minutes, can be an overwhelming challenge. Dr. Jayabalan’s lab is looking for a promising alternative: the use of an anti-gravity treadmill that allows patients with knee OA to walk longer without increasing joint pain, while still reaping all cardiac benefits.
Anti-gravity treadmills are increasingly common in physical therapy regimens for patients recovering from ACL and other knee injuries. These devices enclose the patient’s lower body in a vacuum and allow the therapist to vary the body weight load patients feel as they walk or run on the treadmill.
In a pilot study, Dr. Jayabalan’s team observed 30 patients with knee OA over the course of two 30-minute sessions. In one session, the research subjects attempted to walk for 30 minutes on a treadmill at their full body weight. In the second, they attempted the same goal on an anti-gravity treadmill, set to reduce body weight by 50%. The results of the study were overwhelmingly positive.
“We have had subjects who felt they could not walk for 15 minutes on a flat surface, but when they were walking on the anti-gravity treadmill and we reduced their body weight, they were able to walk the full 30 minutes,” he said. “The reduced body weight allowed them to walk longer due to significantly less joint pain and they gained the full cardiovascular benefit of 30 minutes of exercise. Furthermore, their responses to biomarkers indicated significantly less stress on their cartilage and improved gait parameters. “
Clearly, anti-gravity treadmills are showing promise for these patients, but they are expensive. The good news, Dr. Jayabalan said, is that there is a much simpler, more affordable, and readily available way to reduce the load on arthritic joints: aquatic therapy.
“Even a swimming pool can relieve the patient,” he said. “Buoyancy offers significant biological and biomechanical benefits that could potentially allow someone with knee OA to walk longer without joint pain.”
The Shirley Ryan AbilityLab, formerly the Rehabilitation Institute of Chicago (RIC), is the world leader in physical medicine and rehabilitation for adults and children with the most serious and complex conditions, from traumatic injuries to the brain and spinal cord, to strokes, amputations and cancer. related impairment. The “N. 1 Rehabilitation Hospital in America ”by US News & World Report every year since 1991. In 2017, RIC became Shirley Ryan AbilityLab in recognition of a transformative gift from Patrick G. and Shirley W. Ryan.