The recent storm over possible dangerous complications from popular arthritis pain medications, such as Vioxx® and Celebrex®, may be opening the door wider for increased used of orthotic intervention in knee osteoarthritis (OA). This is good news not only for orthotic manufacturers, suppliers, orthotists, and other health professionals; its also good news for patients.
Recent studies have shown that off-loading knee braces relieve or reduce pain in unicompartmental knee OA. Thus, dependence on non-steroidal anti-infl ammatory drugs (NSAIDs) - with their potential unpleasant side effects - may be reduced or in some cases, eliminated. A pilot study also indicates that GII Unloader® braces, and by extension, possibly other off-loading OA knee braces as well, may actually slow the progression of the disease.
Vioxx and Celebrex and other Cox-2 Inhibitor
NSAIDs have come under fire for increased risk of causing major
cardiovascular complications such as heart attack and stroke. Other
types of NSAIDs can cause gastric pain and complications.
Merck & Co. voluntarily pulled Vioxx off the market in September 2004. However, the Food & Drug Administration (FDA) Advisory Committee voted February 18 in favor of allowing Vioxx, Celebrex, and related drug Bextra® to remain on the market because of their effectiveness in severe pain relief despite health risks. After the vote, speculation emerged that Merck might again put Vioxx on the market.
However, off-loading knee braces that reduce unicompartmental load relieve pain biomechanically, thus eliminating these risks.
An educational website, www.kneepaininfo.com, states that a brace that reduces unicompartmental load may be effective in reducing the symptoms of osteoarthritis of the knee when the osteoarthritis affects only one compartment of the knee. The website goes on to explain some of the biomechanics involved: when one compartment is affected by osteoarthritis, the affected compartment tends to collapse. The goal of the off-loading brace is to unload the weight from the collapsed compartment. A brace is used to put more weight on the healthy lateral compartment and less on the arthritic medial compartment.
"The GII Unloader knee brace is significantly more effective than a simple sleeve. It has been shown in numerous studies to reduce pain," said Kris Daw, product manager for Generation II knee orthoses worldwide. Generation II, now owned by Ossur, produces the Unloader custom-fabricated and prefabricated line of OA knee braces. Off-loading knee braces have shown that they may decrease the need for medication to control symptoms of osteoarthritis of the knee, the website pointed out. The site noted the importance of this for individuals who are unable to take anti-inflammatory pills because of their side effects.
Use of an Unloader brace may delay or even prevent the need for surgery down the road, Daw said. He commented that the majority of patients who use the Unloader brace experience some pain relief and improvement in function.
Studies Support OA Bracing
A study by A. Kirkley, MD, has shown that knee OA patients on
medication have more reduction in pain when a GII Unloader knee
brace is added than when medication alone is used, Daw continued.
Thus, the brace is effective in relieving or reducing pain either
alone or in combination with other modalities.
"We know that an OA brace relieves pain more than hyaluronic acid injection or Cox-2 inhibitors or other NSAIDs - not because an Unloader brace has been compared with them in a single study, but because of the results of the WOMAC (Western Ontario McMaster Osteoarthritis Index) patient questionnaire outcomes," added Kimberly Walsh, vice president of research and reimbursement for Ossur.
The American Academy of Orthopaedic Surgeons (AAOS) released a favorable position statement in 2002 on off-loading braces, "AAOS believes that some unloader braces may provide significant reduction in pain when properly fitted in selected patients with osteoarthritis of the knee."
The statement continues, "Patients with osteoarthritis of the knee and varus or valgus deformity often develop increased pain in the affected compartment due to increased mechanical loading. Unloader/off-loader braces are designed and constructed to reduce asymmetric loading in such knees. There is strong biomechanical data demonstrating reduction in adduction movement in varus knees when the appropriate unloader brace is used. Clinical studies have shown improved pain and function in patients with medial compartment osteoarthritis using some unloader braces." The AAOS statement does add this caveat, "Patients with advanced osteoarthritis or severe varus malalignment would not likely benefit from bracing. In addition, patient compliance is an important consideration."
The American College of Rheumatology and the National Guidelines Clearinghouse also mention knee bracing as a beneficial modality in knee OA management.
Numerous studies support the benefits of offloading knee orthoses in managing knee osteoarthritis. For instance, the Kirkley study concluded, "Compared with a simple sleeve, use of a valgus-producing functional knee brace was shown, on average, to significantly improve quality of life and function." Many of these studies can be accessed from Ossurs website: www.ossur.com
"Using an off-loading brace in combination with other modalities makes terrific sense," said Walsh. "The Unloader brace actually changes the mechanical forces on the knee, and it's these forces that cause the knee on that side to wear out. The anti-inflammatory pharmaceuticals don't affect the biomechanical forces on the knee; they just treat the symptoms of the disease and not the disease itself."
Other Possible Benefits
|Seattle Systems Cruiser OA|
Do any studies show that use of the Unloader
brace, by shifting the biomechanical forces on the knee, can
actually slow the progression of OA? "It's not proven," answered
Walsh, "but a pilot study shows a trend in that direction. Marker
enzymes in the synovial fluid that destroy cartilage are shown as
reduced when an Unloader brace is used."
In the same pilot study, the investigator is looking at the effusion volume as well as the enzymes in the patients he is fitting with the Unloader brace, Walsh explained. Inflammation in the knee produces effusion, and in this study excess fluid has been aspirated and measured prior to putting the patient in the orthosis. After the patient has worn the brace for three months, the fluid is again withdrawn and measured. "What the pilot study has found is that the effusion volume is reduced," Walsh continued. "Although a larger study is needed, this pilot study does suggest that the Unloader brace has an effect on infl ammation as well."
Walsh cited research underway by Leena Sharma, MD, associate professor at Northwestern University, Chicago, Illinois. Sharma is not evaluating treatment modalities, but rather is trying to find what factors cause knee OA and what factors cause it to progress. Knee OA progresses very rapidly in some patients and very slowly in others. Why? This is a question to which Sharma seeks the answers.
"Once we know just what causes knee OA and what causes it to progress, we can then know what factors can be controlled," Walsh pointed out. "There are probably several factors involved. We can then better decide what drugs, devices, or surgeries are most appropriate."
OA knee orthosis use has been growing at a reasonable rate for about the last ten years, according to research organizations that track medical device utilization, Daw observed.
Commenting on the AAOS position statement, Walsh said that it will take awhile for it to percolate through the medical community. "We expect this statement will generate more use of the brace, not only among orthopedic surgeons but also among primary care physicians and other healthcare professionals," she added.
Said Daw, "I certainly expect a lot of innovation in this industry in the next five years."
Besides Ossur, some other companies manufacturing OA knee orthoses are: Seattle Systems (CruiserTM); www.seattle-systems.com ; Townsend Design (Reliever Air and Reliever OA), www.townsenddesign.com ; Bledsoe Brace Systems (Aligner and Thruster 2I), www.bledsoebrace.com ; dj Orthopedics Inc. (DonJoy) www.djortho.com ; and Alts Medical, www.altsmedical.net
This is not a complete list and is for reader information only. The O&P EDGE does not endorse any particular product or service.