Botox, famous for smoothing out those pesky forehead wrinkles, is being used in a new area of the body: the knee.

Researchers in Minnesota have discovered that when Botox is injected into the knee joint, it can reduce the pain of osteoarthritis.

“This is very exciting because it is a new option for patients with severe knee pain due to osteo-arthritis,” says Dr. Maren Mahowald, the study’s main author and chief of rheumatology at the Minneapolis Veterans Affairs Medical Center. “It appears to be long-lasting and safe.”

In a clinical trial involving 37 people with knee pain, Ma-ho-wald’s team injected either Botox or a placebo into the knee joint. A month later, those with severe pain who had received Botox enjoyed a 28% decrease in pain and a 25% improvement in joint function, while those who received placebo felt no improvement. Mahowald will evaluate the patients again at three months and six months. Early results of the trial were announced at the American College of Rheumatology’s annual meeting in Washington in late November.

Pain expert Dr. Ian Finkelstein says that the medical community is treating the results with caution. As director of the Toronto Headache and Pain Clinic, he has seven years of experience using Botox to treat chronic headaches, migraines, lower back and shoulder pain, as well as fibromyalgia and other pain syndromes. The treatment is “superb” in some patients but has no effect in others, Finkelstein says. Before commonly using it for osteoarthritis, he says, doctors will wait for more research: “Results are interesting and it may show promise. But we should not jump the gun and say it works for everybody.”

Canada’s Botox pioneers are delighted that the remedy is making headlines again. Dr. Jean Carruthers is an ophthalmologist who started working with Botox in 1982 for strabismus (misaligned eyes) and blepharospasm (uncontrollable eye blinking). She noticed that using Botox medically had a desirable cosmetic side effect: it smoothed out the wrinkles around the eyes.

In 1987, she and her husband Alistair, a cosmetic dermasurgeon, set Botox on its skyward path to fame and fortune. Botox is now a household name, synonymous with the expressionless smiles on the faces of Hollywood stars who have had their frown lines done. “I have seen Botox cosmetic go from zero to three million treatments last year in the U.S.,” Carruthers says.

Besides reducing frown lines and eye disorders, Botox is used for cervical dystonia (neck spasms) and hyperhidrosis (excessive underarm sweating). Over the past 15 years, Botox has been approved in more than 70 countries for 20 conditions. Doctors are also applying Botox in “off-label” ways: for headaches, migraines, overactive bladder, diabetic nerve pain, lower back pain and neck pain.

Now, add osteoarthritis to the list. “Am I surprised? Yes, of course,” says Carruthers. “But when you know how well it works and how safe it is, it is only a question of time before the educated public also appreciates its many uses and requests it.”

Botox is a purified form of botulinum Type A, a toxin that in another form can cause severe food poisoning. It is injected in tiny amounts directly into a muscle and reduces activity of that muscle by blocking the nerve impulses that trigger contractions.

“It is the most exciting thing to see a drug that was initially thought only to be the most poisonous poison now used worldwide, not only for cosmetic but for other therapeutic indications,” says Carruthers.

For those with knee pain from osteoarthritis, surgery has been the most common strategy. But it is not recommended for many sufferers. For instance, patients may be considered by their doctors to be too young for such an aggressive treatment, or too old to do well afterward. Painkillers called “non-steroidal inflammatory drugs” are often used for osteoarthritis, but stomach problems can be associated with them.

“Local joint treatment with injection could replace oral medications that carry the risk of systemic side effects, and may negate or delay the need for joint surgery,” says Mahowald, adding that much more research is needed to figure out safe dosages and the most effective dosing intervals.

Mahowald believes osteoarthritis patients may require one to three Botox injections per year to stave off the need for surgery.

@page_break@Currently, Mahowald is recruiting patients for a clinical trial of Botox used to treat shoulder pain caused by arthritis. IE