Platelet-rich plasma or PRP is getting a lot of attention these days as a promising therapy for the pain and swelling that comes with osteoarthritis (OA). It’s popular with professional athletes and is the subject of a flurry of new research. But how definitive is the science, and is it right for you?

What It Is

PRP injections are made by taking a small amount of a patient’s blood and putting it through a spinning process to separate platelets from red and white blood cells. The concentrated platelets are then injected into a damaged area, releasing growth factors to aid healing. The injections typically cost between $500 and $2,000 and aren’t generally covered by insurance.

What Studies Show

A growing body of research indicates PRP has promise for OA patients. A study by Slovakian researchers in the May 2012 issue of the American Journal of Physical Medicine & Rehabilitation compared a group given PRP injections to others who received hyaluronic acid  – a more commonly used injectable to target OA pain and swelling. Among the study’s 120 early knee OA patients, the PRP group had better results at three and six month check-ups.

Patients given PRP also had better results than a placebo group injected with saline in a double blinded, randomized, placebo controlled study of 78 patients published online January 2013 in the American Journal of Sports Medicine. Researchers found equal benefits from one higher concentration PRP dose or two doses of a lesser amount, but improvements in pain and function faded for both PRP groups after six months.

And a study of 22 patients with mild to moderate early knee OA by New York’s Hospital for Special Surgery, published online in Clinical Journal of Sports Medicine in March 2013, showed that after one year, one injection of 6-mL of PRP reduced pain nearly 60 percent, improved overall scores by nearly 56 percent and showed no progression of osteoarthritis per joint in 73 percent of patients.

“I think the results are very positive. They are encouraging us to go further in the advancement of this science,” explains lead author, Brian Halpern, MD, chief of the Primary Care Sports Medicine Service at New York’s Hospital for Special Surgery.”

Italian researchers had more mixed results from their double blind, randomized clinical trial published November 2012 in the journal BMC Musculoskeletal Disorders. When comparing one group of patients given three weekly PRP injections to another that received three weekly injections of hyaluronic acid, researchers found that after one year PRP injections were more promising in patients with less degeneration. But they did not recommend them as a first line treatment, saying PRP was no better than hyaluronic acid for middle aged patients with moderate OA symptoms.

Brian Cole, MD, a professor of orthopaedics at Rush University Medical Center in Chicago currently conducting his own trial comparing PRP to hyaluronic acid in knee OA patients, says researchers are feverishly looking for more clear-cut answers.

“Like all these non surgical treatments, PRP injections are not a cure for arthritis,” Dr. Cole explains. “But there have been continued efforts to do the best science possible to show they are effective definitively compared to other options.”