PRP Concerns

Questions about PRP’s efficacy date back to a study published in 2010 in the Journal of the American Medical Association that found the injections were the same as a placebo shot of salt water in healing Achilles tendinopathy. The study’s first author, Robert-Jan de Vos, MD, PhD, a sports medicine doctor in The Netherlands, did a follow up study one year later that again found no difference between PRP and placebo and he still believes research is mixed on PRP’s benefits for OA.

“It might be an interesting treatment option in the future. However, more research in this field is required to evaluate the effects of PRP in cartilage pathology,” Dr. de Vos explains.

University of Maryland researchers echoed that message in their review of new data on OA treatments for 2011-2012 in the May 2013 issue of Current Opinion in Rheumatology. Although they said primary care and sports practitioners are increasingly using PRP injections to treat OA, they found only ‘limited evidence’ of their efficacy and recommended more research.

And when the American Academy of Orthopaedic Surgeons held a forum about PRP in 2011, bringing together some of the top clinicians and researchers on the topic, the group’s consensus was the injections are a possible treatment for OA patients, particularly those not finding relief from other treatments. But the forum stressed PRP’s efficacy for OA remains unproven.

“Early data suggests there is likely to be a formulation that will help treat knee OA,” says Allan Mishra MD, an adjunct clinical associate professor of orthopedic surgery at Stanford University Medical Center in Menlo Park, California who spoke at the forum. “But it’s not quite ready for prime time in knee OA because we haven’t had it replicated in studies.”

Forum members also stressed that not all PRP is the same, since concentrations can include varying amounts of platelets and white blood cells. That prompted Dr. Mishra to create a classification system for researchers, published in the June 2012 issue of Current Pharmaceutical Biotechnology.

“This is crucial because people want to paint a broad brush - does it work or not - and you have to say what type of PRP and for what,” Dr. Mishra explains.

He says the good news for patients is that a lot more research is underway. But for now he and many others believe the vast majority of OA patients should remain cautious about PRP.

“If you have tried everything else and you are considering something highly invasive, it appears the data for PRP is reasonable,” Dr. Mishra says. “But you need to be specific about what kind of PRP you are getting, and I’m just not sure it is ready for wide patient use in knee OA.”