It’s called PRP, or platelet-rich plasma injection. There was a lot of press about it when a doctor in Toronto was charged for allegedly importing controlled or banned substances into Canada and the U.S. He had allegedly been using these substances for the treatment of some high-level athletes. Although these allegations haven’t been proven, and the athletes’ handlers deny any use of these substances, the issue of PRP was elevated to headline news.
PRP involves drawing blood from a patient, just as you would for a blood test, then spinning the blood in a centrifuge to separate out the cellular part of the blood from the plasma, or liquid part. This plasma is then reinjected into the patient at the site of their injury.
The idea is that chronic injuries fail to heal because there isn’t enough blood flow into those areas, to deliver the constituents in the plasma that are necessary to heal. By injecting the plasma directly into that area, one is supposed to improve healing.
But a study done in the Netherlands, published earlier this year in the Journal of the American Medical Association, showed that there is little benefit to the technique.
This study was a double-blinded, placebo-controlled study. This means that neither the researchers nor the patients knew if they were actually getting the PRP injection or an injection of salt water. 54 people with Achilles tendonitis were assessed, half got the PRP and half got the saline injection. All of them also had exercises prescribed. At the end of the six-month study, although both groups improved, there was no difference in the two groups in terms of their pain level or their activity level.
In other words, there was no significant effect of PRP in this study.
Other studies done on PRP have not been blinded. This biases patient to thinking that they’re going to get better. If you tell someone you’re doing something that will help, even if all you’re really doing is injecting saline, or giving a sugar pill, up to one-third of patients feel better. This is the placebo effect. By telling people you’re doing something helpful, some will feel better. If you charge people significant amounts of money for treatment, it means that already, even before doing treatment, those people who decide they’ll spend the money will more likely believe that the treatment helped. After all, they spent all that money, so the treatment must work, right?
While this technique has gotten a lot of press lately, there isn’t the body of scientific evidence behind it to make me comfortable recommending it or offering it to my patients.