However, to properly confirm this, long-term studies in humans should be performed. “Many sports injuries lead to a rapidly developing osteoarthritis, and such disease would present a good target for immediate studies.”

Lubricating Joints with Lubricin

For two decades hyaluronic acid supplements have been a popular treatment for knee OA. Designed to supplement a substance that is deficient in the joint fluid of osteoarthritic knees, hyaluronic injections provide many people temporary relief from pain and stiffness, yet they appear to do little to stop the progression of joint damage. Now scientists are finding evidence that replacing another substance – lubricin – might.

Lubricin, like hyaluronic acid, is a substance in joint fluid that helps give it is viscosity. But rather than just reducing friction between joint surfaces, researchers at Duke University in Durham, N.C, and Rhode Island Hospital in Providence discovered several years ago that lubricin forms a barrier that repels joint surfaces to prevent their contact. Now, researchers have shown, in two different animal models, that a deficiency in lubricin leads to increased friction in the joint, which in turn leads to the death of cartilage cells.

Furthermore, in the most recent study, published in the April 9, 2013, issue of the Proceedings of the National Academy of Sciences, researchers found that not only that lubricin deficiency led to the death of cartilage cells, but in a bovine cartilage model, the addition of lubricin significantly lowered the number of dying cartilage cells.

The findings about lubricin suggest that lubricin injections could potentially be a way to stop cartilage damage in people whose joint fluid is deficient in the protein, says Stefan Zauscher, PhD, a biomedical engineer at Duke University. He suggests that the best time to study lubricin injections is following a joint injury that that is likely to progress to osteoarthritis later in life.

Repairing Cartilage with Stem Cells

Unlike most of the body’s other tissues, cartilage has little ability to repair itself when damaged. Research, however, suggests that stem cells can help repair the damage. Stem cells are undifferentiated cells, meaning they have the potential to become other cells with specialized functions. They can be isolated from a variety of adult tissues, including bone marrow and fat, and grown in culture without losing their potential to differentiate into specialized cells.

In research in both animals and people, stem cells have been used to fill in and repair small defects in joint cartilage. Now research shows that certain stem cells may do more than grow to fill in defects joint cartilage, they may also have properties that stop the damage.

Researchers, including Giovanna Desando at the Rizzoli Orthopedic Institute in Bologna, Italy, have shown that adipose-derived stem cells – that is, stem cells isolated from fat tissue – express anti-inflammatory characteristics when injected into osteoarthritis joints. In a study published in a 2013 issue of Arthritis Research and Therapy, Desando and her colleagues further found that a single injection of adipose-derived stem cells directly into osteoarthritic knee joints of rabbits, protected against cartilage damage. 

While this and other studies, mostly on animals, suggest that intra-articular injections of stem cells could potentially stop OA damage, years of studies on people are likely needed to confirm this, researchers say.

What You Can Do Now

All of these potential therapies hold promise, yet further research is needed to confirm their effects and/or to evaluate the risks versus expected benefits. In the meantime, however, there are things you can do help slow osteoarthritis progression, particularly in the knee: Use a cane to reduce stress of the affected knee, lose weight if you are overweight and wear a knee brace if your doctor or physical therapist prescribes one.

“[While] this research opens up the exciting possibility that OA may be modified by drugs, people should still focus on lifestyle factors – weight and exercise – as important issues to address in their health,” says Kadam.