When patients with hip osteoarthritis (OA) have difficulty with pain and movement, doctors sometimes prescribe physical therapy. The conservative therapy – which often includes a combination of manual therapy (the use of hands to manipulate joints and put pressure on muscles), therapeutic exercises (targeting strength, flexibility and balance), massage and education under the direction of a trained physical therapist – offers minimal risk and is often covered to some extent by insurance plans. But while physical therapy is a well-accepted approach in the United States as well as internationally, and studies have shown the benefits of exercise and of manual therapy individually, no placebo-controlled trial has examined the effectiveness of a combined physical therapy program.

To close this evidence gap, a team of researchers in Australia, led by Kim L. Bennell, PhD, director of the Centre for Health, Exercise and Sports Medicine at the School of Health Sciences at the University of Melbourne, designed a study to measure how well physical therapy works. The results? The patients on a physical therapy program did improve in terms of pain and function – but those who had placebo (sham) physical therapy treatments improved just as much, and even a little more in some cases. Their findings appeared recently in The Journal of the American Medical Association (JAMA).

About 25 percent of adults in the U.S. will develop hip arthritis in their lifetime, according to the Centers for Disease Control and Prevention (CDC). No currently available therapy slows down or reverses the cartilage wear that occurs in the disease, so treatments focus on improving pain and function as well as delaying or preventing joint replacement. Many doctors and professional organizations – including the American College of Rheumatology (ACR), the European League Against Rheumatism (EULAR) and the Osteoarthritis Research Society International (OARSI) – recommend daily exercise, such as walking or swimming, to relieve symptoms and maintain mobility in arthritis patients. Some, including the ACR and OARSI, also recommend physical therapy.

Bennell and her colleagues recruited 102 people with moderate OA-related hip pain and followed them for nine months between 2010 and 2013. All were 50 years of age or older and none had undergone physical therapy or exercised more than 30 minutes per day for the previous six months.

Study participants were randomly assigned to either an active or a sham treatment group. Those in the active group had 10 physical therapy treatments with experienced therapists during a 12-week period. Treatments included hands-on manipulation of the hip and, massage, education and instruction on the proper use of a cane, if needed. Additionally, they were given exercises to perform at home several times a week. The placebo group received fake ultrasound treatments using an inactive gel but no manual therapy, exercise instruction or other intervention.

After 12 weeks of treatment the participants in both groups were followed for an additional six months. During that time, the active group continued the prescribed exercises on their own and the placebo group continued to apply the inactive gel three times per week.

Participants were assessed for pain and physical function before the study (at baseline) and at 13 and 36 weeks after the start of the study. Pain was measured using the visual analog scale (VAS), where 0 represents no pain and 100 is the worst pain imaginable. Physical function was measured using a standard scale with scores ranging from 0 (no difficulty) to 68 (extreme difficulty).

To determine how well participants could function physically, researchers looked at range of motion, muscle strength, stair climbing ability, walking pace and balance. They also looked at other measures, including quality of life, the intensity of pain while walking and treatment side effects.