New York—July 23, 2012
Researchers at Hospital for Special Surgery (HSS) have launched a study that could lead to a powerful, noninvasive treatment for painful knee osteoarthritis (OA). Howard Hillstrom, Ph.D., and colleagues at the Leon Root, M.D., Motion Analysis Laboratory are enrolling people in a study to see if “conservative realignment therapy” helps relieve knee pain and improve function.
The goal is to gently alter individuals’ knee alignment with a light and flexible custom-fitted knee brace. Based on previous studies, the HSS researchers believe that realigning the knee using the custom brace can significantly reduce pain and has the potential to slow the progression of osteoarthritis.
Knee osteoarthritis is the most common disabling condition, affecting an estimated 9.3 million people in the United States. Patients with severe knee OA account for more than 580,000 total knee replacement surgeries in the U.S. each year.
“Studies suggest that only a small fraction of the people suffering from osteoarthritis need operative treatments,” said Dr. Hillstrom, director of the Motion Analysis Laboratory. “One research group found that approximately half a million knee OA patients will require an operation in a given year, while more than 5 million patients will require non-operative treatment.”
There is no cure for osteoarthritis, but if the lightweight brace is shown to help people, it will be a significant development in the primary care of knee OA, according to Dr. Hillstrom. “Such noninvasive treatment is important for people who cannot take NSAID medications such as ibuprofen because of side effects, and for the millions of patients who are not candidates for knee replacement surgery,” he said. “If the brace is shown to slow down the progression of OA, it may also help delay joint replacement surgery. Both disease prevalence and the expected number of total joint replacements are projected to significantly increase due to the aging baby boomer.”
The HSS study is recruiting individuals who have osteoarthritis in the inner area of their knee, known as the medial compartment. The objective is to realign the knee to take pressure off the arthritic area.
Participants are fitted for a custom brace and followed for a year. Nine patients who have completed the one-year study so far have shown improvement in both pain and function, according to Dr. Hillstrom. Based on the 17 subjects who have entered the study to date, significant pain reduction resulted after one week of knee brace use. Preliminary findings have been presented at several professional conferences, including the Osteoarthritis Research Society International meeting in Brussels (2010), the Gait and Clinical Movement Analysis Society (2011) and the Orthopedic Research Society (2011) and published in two journal articles: Clinical Orthopedics and Related Research (2011) and Lower Extremity Review (2010).
“The study brace is a lightweight and flexible device that should not be confused with the clunky components and large metal bars of braces from years past,” Dr. Hillstrom noted. “Patients can wear this brace under their pants, and it does not interfere with activities, such as walking or riding an exercise bicycle.” They are asked to wear it for a minimum of six hours daily for five days a week. But researchers have found that people report wearing it more often, and some individuals wear their brace all day.
Sixty-three-year-old Robert Blau, a math professor with a Ph.D. who teaches at Baruch College in Manhattan, says the brace has enabled him to get rid of the cane he was using to walk. He has experienced a major reduction in pain. While he used to take ibuprofen several times a day, he now takes it once every few weeks, if at all, he says.
Mr. Blau, who lives in Westchester, considers himself lucky to have found out about the study. “I couldn’t have continued commuting and teaching without the brace. It’s made my professional life a lot easier,” he says. “I’m on my feet a lot when I teach. Before using the brace I had to sit down for most of my lecture. Now I remain standing for the entire class. In addition, it’s so much easier to go up and down the stairs between classes.” Mr. Blau says he can walk faster and longer than before. He now walks, in less than half an hour, more than a mile each way to his house of worship each Saturday.
When the study was over for him in March 2011, he decided to continue wearing the brace every day during most of his waking hours. He feels that although he may eventually need a knee replacement, the brace is buying him time. “My goal is to wait as long as possible for knee replacement to take advantage of the technological advances we will surely see in the field.”
Study participants fill out surveys to analyze their level of pain and ability to function when they start the study, four months into the study, and at one year. In addition to the surveys, they engage in a process called 3D motion analysis that reveals how their muscles and joints are working while performing different activities.
In the Motion Analysis Lab, researchers attach bright surface markers to different parts of the individual’s body. Twelve cameras around the room are tracking the markers, recording what the body is doing. “We merge the images from all of the cameras and create a three dimensional picture of the person performing activities such as walking and climbing stairs,” Dr. Hillstrom explains. “Computer programs are used to analyze the subject’s movements and reveal how one’s muscles and joints are functioning. Coupled with structural data from lower limb X-rays, pain experienced while performing activities of daily living, and the body’s biomechanical function while walking, the investigators are learning how the patient with OA responds to the improved lower limb alignment (medial compartment offloading) provided by the brace.”
Motion analysis allows researchers to objectively measure the gains achieved following medical or surgical intervention -- in this case, the use of the brace.
Dr. Hillstrom says the knee brace study is the first of many the Motion Analysis Lab will be conducting to find new and better treatments for knee osteoarthritis. Anyone interested in seeing if he or she qualifies for the study is invited to call 212-606-1215.