Osteoarthritis, sometimes called degenerative joint disease, is the most common form of arthritis. It occurs when the cartilage in joints wears down over time. Symptoms can include pain, tenderness, stiffness, and inflammation. Studies have suggested that symptoms of knee osteoarthritis may be caused by abnormalities at the patellofemoral joint, which is the joint between the kneecap, called the patella, and the thigh bone, called the femur. This study will determine whether wearing a knee brace that realigns the patella over the femur is effective in relieving pain and improving function in adults with knee osteoarthritis.

Bending and straightening at the knee causes the patella to glide along a groove in the femur bone. However, biomechanical imbalances can cause the patella to jump off track, which can lead to pain. Interventions that alter the load distribution across the patellofemoral joint, such as patella taping, may be helpful in alleviating symptoms. Patellar taping has in fact been shown to be effective in the short-term for treating patellofemoral osteoarthritis. But it has not been widely adopted in the clinical setting because it is complicated to administer, difficult to educate the patient about ongoing application, and lacks evidence of long-term efficacy. Also, patients often experience skin irritation from the taping and discomfort when removing the taping. An alternative treatment option is the use of a knee brace that realigns the tracking of the patella. This study will determine whether wearing a patellofemoral realigning knee brace is effective in relieving pain and improving function in adults with knee osteoarthritis.

Participation in this study will last about 3 to 9 months. All eligible participants will wear the same knee brace for a 2-week run-in period during which they will record when they wear the brace and any pain medication used. Next, participants will be randomly assigned to wear one of two knee braces for 6 weeks and a minimum of 4 hours each day. This will be followed by 6 weeks of wearing no knee brace, and then by 6 weeks of wearing whichever knee brace they did not wear during the first 6-week period. There will be a total of nine study visits. The first study visit will screen for eligible participants and will include an interview, knee evaluations, x-rays, and a urine pregnancy test. The second and sixth study visits will include knee evaluations, brace fittings, and instructions on how to correctly wear and adjust the brace. Most of the other study visits will consist primarily of interviews and functional tests. During the first and third 6-week periods, participants will maintain a log to record how long they wear their braces and any pain medication used. Participants will also wear an accelerometer, which will keep track of how many steps they take.

Participants will have the option of continuing in a 6-month follow-up period during which they can wear the brace of their choice. There will be three evaluations that will include questions on how participants are doing with their braces.

Inclusion Criteria:

• Knee pain on most days
• Either isolated patellofemoral osteoarthritis or mixed patellofemoral and tibiofemoral osteoarthritis, as based on x-ray

Exclusion Criteria:

• Bed- or chair-bound, usually uses an ambulation aid to walk (e.g., cane, crutch, or walker), or uses a wheelchair
• Pain emanating more from the back or hip than from the knee, as determined by screening questionnaire
• Low pain score on the visual analog scale (VAS) (less than 4 out of 10)
• Plans to move from the area within 10 months of study screening
• Symptomatic comorbid disease that limits activities more than knee pain does, as determined by screening questionnaire (e.g., congestive heart failure, chronic obstructive pulmonary disease)
• Receiving corticosteroid injections in the month before study entry, or receiving hyaluronan in the 6-month period before study entry. No other treatments will result in exclusion, although for patients taking glucosamine and/or chondroitin and/or a non-steroidal anti-inflammatory drug (NSAID), they must have taken these treatments for at least 2 months before study entry and must commit to not start a new treatment during the study.
• Bilateral total knee replacements or plans for a total knee replacement of the affected knee in the next 6 months
• Morbidly obese (body mass index greater than 35), as brace fitting and prevention of slippage of the brace will be difficult
• Known other causes of arthritis, including rheumatoid arthritis, systemic lupus erythematosus, gout, psoriatic arthritis, and pseudogout
• Skin breakdown at the site where the brace will be applied
• Failure to pass the run-in test, or the brace falls down the leg during the run-in

There was no control group without a brace for comparison to the intervention because of concerns about unblinding.