Platelet-rich plasma doesn’t work for rotator cuff (shoulder) tendons

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Yet another salvo in the ongoing debate about whether platelet-rich plasma (PRP) therapy — sometimes known as “blood spinning” — is a miracle tendon healer or an expensive placebo. At an American Orthopaedic Society for Sports Medicine conference in San Diego, researchers presented the results of a new study of PRP for rotator cuff tendon repair — and the results weren’t encouraging.

The study involved 79 patients who all received standard surgical rotator cuff repair and post-operation rehab; half of them were randomized to receive a form of PRP treatment. There were “no real differences” between the groups:

“In fact, this preliminary analysis suggests that the PRFM [the form of PRP used in the study], as used in this study, may have a negative effect on healing. However, this data should be viewed as preliminary, and further study is required” said study author Scott Rodeo, MD, of New York City’s Hospital for Special Surgery.

Right now it’s just a conference presentation; the study will presumably be published eventually, at which point we’ll get some more details on the design and specific results of the study. But the scientists still seem optimistic:

Researchers think there may be several reasons for a lack of response in healing, including variability in the way platelets are recovered, platelet activation and the mechanisms for the way the PRFM reacts with the tendon cells. The study was also unable to document the number of platelets actually delivered to patients who received the PRFM…

“Additional research needs to be performed to figure out the mechanisms for why PRP is successful in healing certain areas of the body and not others…” said Rodeo.

I’m not really sure which areas of the body he’s talking about. I only know of one properly controlled clinical trial that came to a positive conclusion, on tennis elbow — but even that study was subject to criticism. So far PRP is one of those ideas that makes perfect sense in theory, but hasn’t yet proven itself in practice.