Physical Therapy and Exercise for Knee Arthritis

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The summary below is from the full report titled "Effectiveness of Manual Physical Therapy and Exercise in Osteoarthritis of the Knee. A Randomized, Controlled Trial." It is in the 1 February 1999 issue of Annals of Internal Medicine (volume 132, pages 173-181). The authors are G.D. Deyle, N.E. Henderson, R.L. Matekel, M.G. Ryder, M.B. Garber, and S.C. Allison.

What is the problem and what is known about it so far?

Osteoarthritis is the most common type of arthritis. One third of people between the ages of 63 and 94 have osteoarthritis in their knees that can be painful and may limit their ability to get up from a chair, stand, walk, or climb stairs. Treating ostearthritis with drugs does not always work well and often leads to drug-related side effects. There is some evidence that physical therapy and exercise helps people with osteoarthritis.

Why did the researchers do this particular study?

The researchers wanted to see whether specially designed physical therapy by experienced therapists, which included hands-on (manual) therapy and a supervised exercise program, would reduce pain and stiffness in persons with knee osteoarthritis and increase their ability to walk comfortably.

Who was studied?

Eighty-three patients with knee arthritis whose doctors had referred them to the physical therapy department of a large military hospital.

How was the study done?

At random, the researchers assigned patients to receive either the physical therapy program or placebo. (Placebo is an inactive therapy provided to a comparison group.) The placebo in this study was ultrasound treatment of the knee that was too weak to produce any medical effect. Physical therapy consisted of manipulation of the knee, hip, spine, and ankle by experienced therapists; patients were also taught knee exercises that they did both in the clinic and at home. The physical therapy and the placebo treatments were carried out two times a week for 4 weeks. At the beginning and end of the study, the researchers asked patients to rate their pain and stiffness by using a standard questionnaire. They also measured how far patients could walk in 6 minutes. Patients were then followed up for 1 year to see who needed surgery for their arthritis.

What did the researchers find?

Patients who received the physical therapy program increased the distance they were able to walk in 6 minutes. Patients who got placebo treatment showed no improvement in the distance walked. Physical therapy patients also reported less pain and stiffness than placebo patients. At 1 year, 5% of the group that had the physical therapy program and 20% of the placebo group had undergone knee surgery.

What were the limitations of the study?

It is not possible to determine whether it was the manual therapy, the exercise, or both aspects of the physical therapy program that helped patients. It is also not clear whether home exercise programs in the absence of physical therapy would achieve similar benefit, or whether the benefits of physical therapy and exercise extend longer than 1 year.

What are the implications of the study?

A physical therapy program consisting of manual therapy and exercise seems to benefit patients with knee arthritis. It may also delay or prevent the need for surgery.