Research advances will turn more nonoperative OA treatments into reality

FDA approved a topical OA gel amidst mounting evidence for using nutraceuticals, injectables.

Issue: February 2008

More than 40 million Americans have been diagnosed with osteoarthritis and that number is expected to steadily increase due to an aging and overweight population. Because surgery is not the answer for everyone, researchers predict that in the future more individuals will have their osteoarthritis addressed nonsurgically to minimize its impact on their daily activities and quality of life.

“The vast majority of people with osteoarthritis (OA) in one or more joints never see a surgeon,” nor do they need to, Joseph A. Buckwalter, MD, said.

But to manage the pain and symptoms of the disease, people with OA and their physicians may consider a range of less-invasive modalities, including topical solutions, over-the-counter medicine, nutraceuticals, physical therapy, splinting and bracing.

Research shows some of these are highly effective for restoring range of motion, while others may positively impact OA-affected joints, by modifying the disease. Future approaches for treating OA may offer even more benefits, according to Buckwalter.

“What is attractive are methodologies that safely and noninvasively tell us when the joint is starting to degenerate or is at risk of degeneration and then tells us if a drug or an intra-articular injection and/or activity modification can prevent progression of the disease or reverse its early stages,” he said.

Patient-specific options

An important consideration for current OA therapies is that not all of them have the complete safety and efficacy data many orthopedic surgeons require. The result: some are hesitant to fully embrace theses treatments without more proof of their effectiveness.

“There is reasonable evidence a number of other approaches — weight loss, muscle strengthening, certain kinds of bracing, shoe inserts, activity modification — can also relieve pain and improve function,” Buckwalter said.

Thomas L. Wickiewicz, MD, said at a recent meeting that the nutraceuticals literature, for example, has not convinced him they change articular cartilage substantially, “but the injectables are worthy of more study because they might be beneficial to the joint.”

Even in the absence of solid evidence, most would agree that if initiated early, some conservative strategies preserve the joint or delay the need for surgical interventions like joint reconstruction or osteotomy.

“OA is obviously not life threatening but can profoundly affect quality of life and function,” Buckwalter told Orthopedics Today.

Arthroplasty or osteotomy may not be indicated for every patient with knee OA. Some can modify their disease through oral therapies, injections or pulsed electrical stimulation.

Almost 10% of all people older than 50 years have osteoarthritis, according to national statistics. Nonoperative treatments used alone or in combination present a possible course of care for many of them.

Images: Clayton JJ

Topical gel approved

The FDA has approved the first topical OA treatment, diclofenac sodium topical gel (Voltaren Gel 1%, Novartis), which investigators found as effective as diclofenac with less systemic absorption.

Roy Altman, MD, said in a press release, “Voltaren Gel is proven to be effective for osteoarthritis of the hand and knee and has a favorable safety profile. The combination of benefit and safety provides a welcome new treatment approach for osteoarthritis, offering patients an alternative to oral therapies.”

With increased high energy trauma in young people, “Earlier onset OA is likely to be a good indication for nutraceuticals, in order to stave off the requirement for joint replacement,” such as chondroitin sulfate and glucosamine, James J. Clayton, BSc(Med), MB, BS, said.

Oral supplements

Oral use of nutraceuticals is predicted to increase and research into ways to introduce them directly at the site of OA is also underway.

“As an overall class of therapeutics, they generally have minimal and minor side-effects,” depending on coexisting comorbidities and medications, Clayton said. But, “there appears to be an imbalance between apparent structural benefit and symptom relief,” he noted.

Clayton told Orthopedics Today all nutraceuticals demonstrate various mechanisms with potential for being effective in treating OA, including anti-inflammatory and analgesic properties, but are traditionally subjected to less rigorous clinical investigations that may be inconsistently conducted.

Collagen hydrolysate

After chondroitin and glucosamine, “SAMe, Boswellia, collagen hydrolysate, diacerein, oxaceprol and avocado-soybean have been the nutraceuticals most thoroughly investigated in my opinion,” Clayton said.

“Collagen hydrolysate is a nutraceutical that demonstrates promise in the management of OA. [It] appears to provide symptomatic improvement by stimulation of chondrocytes to synthesize extracellular macromolecules in cartilage,” he said.

Sulfites may be another future direction, Clayton said. “I believe nutraceuticals may have a role to play in the future management of OA, although they may be in a more refined product as we learn more about their mechanisms of action.”

Electrical stimulation

According to David S. Hungerford, MD, electrical stimulation presumably affects how cartilage responds to damage: “The hypothesis is specific fields selectively regulate cartilage gene expression and applied fields restore in situ electrical signals” lost due to cartilage breakdown from OA.

Whatever the nonoperative course, “It’s important to direct your treatment towards the underlying pathology the patient has, as well the patient’s age, activity and his willingness to modify his activity,” Timothy G. Reish, MD, said.

For more information:
Joseph A. Buckwalter, MD, can be reached at University of Iowa Hospital, Dept. of Orthopedic Surgery, 200 Hawkins Drive, Iowa City, IO 52242; 319-356-2595; e-mail: joseph-buckwalter@uiowa.edu.
James J. Clayton, BSc(Med), MB, BS, can be reached at Dept. of Orthopedics and Trauma, Royal Adelaide Hospital, North Terrace, Adelaide, Australia SA 5000; 618-8222-4000; e-mail: jjc007@bigpond.net.au.
David S. Hungerford, MD, can be reached at Good Samaritan Professional Bldg., Suite G1, 5601 Lock Raven Road, Baltimore, MD 21239; 410-532-4732; e-mail: truby2@jhmi.edu.
Timothy G. Reish, MD, can be reached at 210 64th St., 4th Floor, New York, NY 10021; 212-434-4440..
Thomas L. Wickiewicz, MD, can be reached at Hospital for Special Surgery, New York, NY 10021; 212-606-1450; e-mail: Wickiewicz@hss.edu. No source has any financial interest in any products or companies mentioned in this article.