Over the past couple years, a new term has crept into the public consciousness from the shadows of medical experimentation. Platelet rich plasma injections or "PRP" have become commonplace, especially for cases where an athlete is trying to avoid surgery. It is being used by superstars in other sports, with Dwight Howard, Kobe Bryant, Tiger Woods, Ray Lewis and Peyton Manning all using PRP in some fashion. Now, there is finally some scientific evidence that PRP works.
Hearing that someone has had a PRP injection is hardly news any more. Indeed, it is a matter of course in many rehabs. Dylan Bundy and Jonny Venters are recent examples of pitchers who have had injections during their rehabs, but in both cases, they ended up needing surgery. There are more, such as Takashi Saito, Chris Britton, Alex Rodriguez and Zack Greinke, who have had much more success after their injections.
However, few understand what this term means and fewer still understand the reasoning behind its use. Medical technology moves fast, so it's not unusual that the public is lost when it comes to new techniques. In this case, the doctors don't know much more. PRP injections are used without a real understanding of the mechanism or even if it works at all!
PRP injections take blood from a patient, then spin it in a centrifuge to create a solution that is then re-injected. In most cases, the blood is outside the patient for less than an hour. Nothing is added to the blood in the standard procedure, though more advanced procedures do add in other substances, including HGH, which is banned in most athletics.
At the annual ASMI Injuries in Baseball course in 2012, Dr. James Andrews, one of the top sports medicine surgeons in the world, led a panel discussing the best practice use of PRP. During that panel, Andrews acknowledged that he was using PRP in many of his cases. "I don't know if it works," he explained, "but I know it's not hurting anyone."
The anecdotal evidence cited by Andrews was concurred by several other top surgeons on the panel. Finally, we have some science behind the use. In the May 2013 edition of the American Journal of Sports Medicine, a study was published that gives the first positive evidence of PRP usage.
The study, led by Dr. Luga Podesta and co-authored by the late Dr. Lew Yocum, indicates a very positive trend, with 88 percent of athletes in the study returning to play without further surgery. Moreover, the study showed real physical changes inside the elbow, indicating more than just a placebo effect at work.
Indeed, this could indicate that the technique should be used more often than current, as many pitchers are asymptomatic with shoulder and elbow issues but are in what doctors call an "insidious phase," where there are physical changes and deterioration inside the joint space. Dr. Andrews has famously said that if you want an excuse to do surgery, just perform an MRI on a pitcher.
I spoke with Dr. Podesta on Monday and he explained that he is still a big proponent of "if it ain't broke, don't fix it." While the results he sees from his long-term use of PRP, which goes well beyond the scope of this study, are overwhelmingly positive, he doesn't yet see it as a preventative measure.
Dr. Podesta does note that the use of ultrasound in directing the procedure is a big help. "The use of PRP can be very specific when guided, putting it exactly where I want," he explained. "Dr. Ciccotti (the team physician for the Philadelphia Phillies) has shown great things in terms of dynamic usage of ultrasound." Dr. Podesta also notes the different preparations which are being used. "There's still debate about leukocyte-heavy or leukocyte-poor, different things. In this study, we kept it simple and controllable."
While the study does show positive results, there's still no understanding of the mechanism. In this study, it was a very simple procedure, with very little preparation or extra therapy. Many doctors, including Dr. Mark Niedfeldt, have theorized that the needling itself could be having an effect on the area, as he noted in this article by Bleacher Report's Dr. Dave Siebert.
The study's simplicity also excludes any suggestion that more advanced treatments like Regenokine or bone marrow concentrate offer similar results. Regenokine is a more complex preparation, which spins the blood for a longer period of time than allowed under current American rules, as well as adding substances to the injection. This is why Bryant, Manning and others have had to travel to Germany or Switzerland for treatment.
The treatment is under investigational usage in the United States but is not approved yet. Intriguingly, the American tests are being run by Dr. Christian Renna, who has an interesting background that includes ties to BALCO and Oliver Stone. Throughout sports, we're about to see an expansion of the needle as a healing technique at the same time the same sports world is struggling to deal with performance enhancers, doctors using shady science and painkillers.
The published study certainly suggests that PRP should be a regular part of rehabs and that the success rate is certainly suggestive of an effective internal method. While this is cold comfort to Dylan Bundy or Orioles fans, there is now real evidence that the attempt to rehab through a partial tear is the correct course in most cases.
The imprimatur of science may see this technique expand even further, especially as more anticipated studies publish in the coming year. Expect a lot more needles in sports—legal ones.
Will Carroll has been writing about sports injuries for 12 years. His work has appeared at SI.com, ESPN.com and Rotowire. All quotes were obtained firsthand unless otherwise noted.