What a pain

Foster’s osteoarthritis, a wearing down of the cartilage that cushions the bones in joints, had become so acute that she could barely walk, something she loves to do.

“I haven’t got time for arthritis,’’ said Foster, “that’s old people, not me.’’

But increasingly, it’s not just old people. And that’s what worries disease trackers.

A tsunami of aching Americans is looming, say specialists, who predict that 67 million adults - a quarter of the adult population - will have arthritis by the year 2030. The vast majority will be hobbled, as Foster is, by osteoarthritis, which typically increases with age. (Another form of the disease, known as rheumatoid arthritis, is a chronic inflammation of the lining of the joints and is far less common.)

With growing numbers of young adults overweight - excessive weight is a major risk factor for osteoarthritis in weight-bearing joints - the legions of those in pain could be much younger and larger than the 67 million projected, disease trackers warn.

With that grim forecast, the Arthritis Foundation is readying a nationwide education campaign to help younger people avoid major risk factors - obesity, inactivity, and joint injuries - and to recognize the disease symptoms earlier so they can take steps to slow the progression.

“It’s not at all uncommon to see severe osteoarthritis in people at age 40 because of the presence of obesity,’’ said Dr. John Hardin, the foundation’s chief science officer.

Also troubling, he said, are the growing number of anterior cruciate ligament, or ACL, knee injuries that high school and college students are racking up in sports these days, particularly young women in soccer and cheerleading.

“People who tear their ACL have a 50 to 75 percent chance of developing severe osteoarthritis in 10 to 20 years,’’ Hardin said. “Even though the orthopedic surgery is very effective in getting you back to playing your sport, it doesn’t change your odds of developing severe osteoarthritis and we really don’t know why.’’

Surgeons are already replacing 500,000 knees a year in the United States, largely because of osteoarthritis, Hardin said, and that number is expected to mushroom over the next two decades.

“Joint replacement surgery is not an answer to osteoarthritis in the long run,’’ he said. “We just can’t replace everybody’s joint every 15 to 20 years like we replace the brake shoes in your car, but that is the direction we are headed in right now.’’

Instead of knee replacement surgery, Foster, the Framingham great-grandmother, elected to try platelet-rich plasma therapy, a treatment used for two decades by oral and plastic surgeons to improve wound healing, but only now being tried by orthopedic and other specialists to treat some sports injuries and osteoarthritis.

A new review in the October issue of the Journal of the American Academy of Orthopaedic Surgeons concluded that although the approach shows promise in laboratory studies - and many patient trials are underway - much larger trials are needed to prove its effectiveness.

The therapy is being studied and used at Spaulding Rehabilitation Hospital in Wellesley, where Foster’s physician removed a small amount of her patient’s blood and spun it in a centrifuge for about 15 minutes to separate the red blood cells from the platelets, which are blood cells that contain chemicals that help the body heal itself. Then the platelet-rich portion of her blood was reinjected in and around both of Foster’s knees. Doctors believe that platelet chemicals, known as growth factor, trigger cell activity that tells the body to start making more cartilage, tendons, and tissue in the damaged area.

“My doctor said there may be pain so I went home and waited for the pain,’’ said Foster, who had both knees treated in September, after a variety of other noninvasive therapies, including anti-inflammatory cream, failed to ease her arthritis pain.

“There is no pain now,’’ Foster said. “None whatsoever.’’

Foster’s physician, Dr. Joanne Borg-Stein, who specializes in rehabilitation and sports medicine, has treated about 175 patients with the injection procedure in the past year, some for osteoarthritis, others for strained ligaments and tendons from sports injuries.

“I like to be honest with patients and tell them that we are just starting to get data in from animal trials, that we don’t have really good human data,’’ Borg-Stein said. “People have to be willing to accept that they are on the leading edge with this.’’

The platelet-rich plasma treatment is one of several new therapies researchers are exploring to slow the disease progression, because there are few good long-term treatments other than joint replacement surgery. Anti-inflammatory medications, typically used for osteoarthritis treatment, can be hard on a patient’s gastrointestinal system and may create other complications in patients over 65, Borg-Stein said.

Research on other popular alternative therapies - including glucosamine and chondroitin supplements and acupuncture - has shown mixed results.

That’s why the Arthritis Foundation is funding research into a variety of approaches aimed at detecting the disease earlier and slowing its progression, said Hardin, the foundation’s science officer.

On the horizon, he said, are new biomarkers that may be able to find early signs of osteoarthritis in blood or joint fluid, similar to the way patients are tested for elevated cholesterol through blood tests and prescribed cholesterol-busting drugs to head off heart attacks. Also in the works, he said, is a new generation of medications that will “bend the body’s response’’ to pain by altering the way nerves pick up pain signals

At Tufts Medical School, Dr. Timothy McAlindon, chief of rheumatology, is wrapping up a clinical trial of vitamin D on 146 patients and its potential effect on heading off osteoarthritis by building up cartilage. His curiosity was piqued after reviewing historic data from another study involving heart disease and found that patients who took higher levels of vitamin D appeared to fend off knee osteoarthritis.

Some of McAlindon’s earlier osteoarthritis research involving glucosamine and chondroitin - he analyzed 15 studies on the supplements - found mixed results.

McAlindon is focusing his research on relatively safe over-the-counter supplements to build cartilage because, he said, that’s what consumers seem to be searching for.

For his own osteoarthritis patients, McAlindon said he finds many have inadequate levels of vitamin D, so he often prescribes booster courses of the supplement.

“Vitamin D is important for bone health, but it may be important for other aspects of health,’’ he said. “You can never tell until you do that controlled, clinical trial.’’

As researchers search for novel new ways to tame osteoarthritis, a guru in the field said one of the most effective approaches for those who are overweight involves weight loss. Studies by Dr. David Felson, a chief of epidemiology at Boston University School of Medicine, include one that found that losing as few as 11 pounds can cut the risk of developing knee osteoarthritis - the most common location for the disease - by as much as 50 percent in some women. Knee arthritis is more common in women than in men, though researchers aren’t sure why.

“We are getting older as a population and overweight as a population and that is scary,’’ Felson said. “But if you get out and get active and lose weight, then your knees will probably improve.’’

Kay Lazar can be reached at klazar@globe.com