Platelet-rich Plasma May Benefit Early Knee OA

A new study suggests the therapy can improve joint pain and function.

Arthritis Today—March 1, 2013

Platelet-rich plasma (PRP), a therapy used to help heal surgical wounds and tendon injuries, may also relieve symptoms of early knee osteoarthritis (OA), according to a new study out of Hospital for Special Surgery (HSS) in New York. Researchers there say patients with knee OA reported significantly improved pain and function for 12 months after a single PRP injection. The findings, published online in Clinical Journal of Sports Medicine, also suggest that PRP may slow joint damage if administered early in the course of the disease.

"The results are very exciting," says Brian Halpern, MD, chief of the Primary Care Sports Medicine Service at HSS and lead author of the study. "This suggests that PRP may have the potential not only to relieve symptoms but also to delay progression of OA, although we don't know if that will continue year after year."

Dr. Halpern stresses that the positive results occurred in people with early OA. "You're not going to be able to do a lot in the regenerative sense for people with bone-on-bone arthritis. By then, the horse is already out of the barn," he says. "But in the earlier stages, you can improve symptoms and the environmental milieu enough to delay or maybe even prevent knee replacement. But that's a long way off and we need to look at a lot more numbers [before we can say that with certainty]."

Still, Dr. Halpern says the study results have prompted HSS to create a registry that will track future osteoarthritis patients over time. Researchers will be able to compare outcomes for various OA treatments, such as exercise, weight control, bracing and hyaluronic acid injections as well as PRP. And for the first time, imaging tests will be used to detect changes in joint cartilage.

It's hoped that the HSS data will help answer some of the many questions that arise as PRP treatments become more common.

"Many more folks are doing it now, especially sports medicine orthopaedists, and they are learning more about why it can and can't work," says Dr. Halpern, noting that he has injected more than 400 patients with PRP over the last five years and all had outcomes consistent with the study results.

"One example is that it appears the platelet concentration has an effect on efficacy, but we don't know what the optimum [level] is right now. That's another thing that has to be explored,” he says. “By definition, PRP formulations have to be two to five times greater than the platelet concentration in the blood. But it seems that if platelet concentration gets as high as eight times greater, it can actually have a deleterious effect."

Dr. Halpern stresses that PRP is not a panacea. "It certainly won't help everybody with everything," he notes. "This is an evolving field, and we need to learn much more."

This story originally appeared at arthritistoday.org.