Although it is not exactly clear how PRP works, laboratory studies have shown that the increased concentration of growth factors in PRP can potentially speed up the healing process.

To speed healing, the injury site is treated with the PRP preparation. This can be done in one of two ways:

PRP can be carefully injected into the injured area. For example, in Achilles tendonitis, a condition commonly seen in runners and tennis players, the heel cord can become swollen, inflamed, and painful. A mixture of PRP and local anesthetic can be injected directly into this inflamed tissue. Afterwards, the pain at the area of injection may actually increase for the first week or two, and it may be several weeks before the patient feels a beneficial effect.

PRP may also be used to improve healing after surgery for some injuries. For example, an athlete with a completely torn heel cord may require surgery to repair the tendon. Healing of the torn tendon can possibly be improved by treating the injured area with PRP during surgery. This is done by preparing the PRP in a special way that allows it to actually be stitched into torn tissues.

Patients usually tolerate the injection well. However, there can be soreness after the injection due to the PRP-induced inflammatory response. You can expect swelling and soreness during the first 48 hours post injection and are given pain medication to help alleviate the discomfort.

Platelet injections are safe. Since you are using your body’s own blood components and there are no foreign substances being injected into your body, the injections are considered safe.

However there is some minimal risk involved. During research studies and clinical trials, the only risk noted was that the injection could cause an infection to develop. This is not unique to platelet injections, anytime a person undergoes an injection there is this risk. But because there are no foreign bodies being injected and there is no concern of disease transmission, this therapy is considered to be safe.

Using one’s own body as a healing mechanism is a relatively new concept in the world of medicine, and an exciting one at that. As therapies such as these begin to prove they are beneficial and effective, you will likely see similar therapies develop in other medical areas.

Injuries treated with PRP therapy include: rotator cuff, quadriceps, hamstring, Achilles tendon injuries and tennis elbow. Essentially any tendon or ligament injury except complete tears may be treated successfully with PRP. PRP therapy is exactly the treatment needed to reduce the downtime of the athlete while also reducing the chance for re-injury or perhaps the risk of a more serious injury that will result in surgical intervention or permanent disability.

You will feel a notable increase in pain in the days immediately following the injection. Pain intensity becomes less each day as functional mobility and general functional ability increase along with endurance and strength. You will notice gradual improvement 2-6 weeks after PRP therapy. Some patients report ongoing improvement 6-9 months after PRP therapy is administered. In some studies, Ultrasound and MRI images have shown definitive tissue repair has occurred after PRP therapy, supporting the proof of the healing process. By treating injured tissues before the damage progresses, surgical intervention may be avoided.

PRP treatment recently gained widespread recognition in the sports world when Hines Ward and Troy Polamalu of the Pittsburgh Steelers received PRP therapy prior to winning Super Bowl XLIII. Other high profile athletes include Tiger Woods who received four treatments following knee surgery and pitchers Takashi Saito and Bartolo Colon — both recent examples of PRP success in Major League Baseball.

Orthopaedic Specialists of North Carolina believes that implementing PRP therapy as a viable procedure may: decrease the progression of more serious injuries, decrease the overall time for healing, and ultimately decrease the overall need for surgical intervention. This promising adjunctive form of therapy holds the potential of healing previously problematic chronic injuries, provide a treatment option for debilitating injuries previously deemed untreatable, and serve as an alternative to surgical intervention.

Mark W. Galland, M. D., Orthopaedic Surgery and Sports Medicine, Orthopaedic Specialists of North Carolina (OSNC). www.orthonc.com

Although blood is mainly a liquid (called plasma), it also contains small solid components (red cells, white cells, and platelets.) The platelets are best known for their importance in clotting blood. However, platelets also contain hundreds of proteins called growth factors which are very important in the healing of injuries.

PRP is plasma with many more platelets than what is typically found in blood. The concentration of platelets — and, thereby, the concentration of growth factors — can be 5 to 10 times greater (or richer) than usual.

To develop a PRP preparation, blood must first be drawn from a patient. The platelets are separated from other blood cells and their concentration is increased during a process called centrifugation. Then the increased concentration of platelets is combined with the remaining blood.

One way or the other, I think over the next six to 12 months it’ll significantly change the way we use PRP. That could be either in a positive way or in a negative way. Maybe that study is going to come out that says, yes, you do need a second injection or a third injection. Right now it’s very subjective how we all use it. Ongoing studies will determine proper usage, including timing and dosage.

The bottom line is that we don’t know enough about PRP therapy. It is safe. We’re using it. Anecdotally it certainly seems to have some positive effects. How much we’ll be using it in the future or what we’ll be using it for, those are all questions that really remain to be answered.

I would say, anecdotally, the whole population overall has done fairly well. There are a number that haven’t noticed much response and then there’s a good number that have done well. I think that’s why we continue [to use it].

A good example is a patient that I have with an Achilles problem and he tried everything, everything, everything—went to other docs and he was all ready for surgery [to remove the scar tissue] and we did PRP therapy on him. He ended up with two sessions of therapy and he’s had a great cure that seems to be related to PRP. And then I’ve had some people, runners with chronic hamstring injury, and they will tell me they haven’t noticed a difference.

I’d probably say that maybe 60 percent of my patients do better.

There is some evidence from cohort studies, and anecdotally we’ve had some good experiences where we still think it’s worthwhile to offer it to some patients. The ones that we offer it to have failed other types of conservative therapy.

Many of the studies early on are animal studies and lab studies. Many of those have been very positive for PRP in terms of tendon-healing effects. That’s part of that lack of evidence. It’s great that the animal studies look good but you need human studies.

Absolutely. In the next six months to a year, we should really start seeing results from many clinical trials, and hopefully good ones, ranging in everything from rotator cuff problems [in the shoulder] to tennis elbow to Achilles and patellar tendonitis.

We all would like to see more evidence for this therapy. While there is some evidence, we still do not have the type of randomized, blinded, placebo-controlled studies that we would like to see. Most of the early literature has been poorly designed studies so we need better evidence about this treatment going forward. Ultimately we’d all like to see a study where we had 100 people with an Achilles tendonitis, 50 of them were injected with placebo and 50 of them were injected with PRP to really see if there was a difference.

The studies that have been performed have been, “Okay, let’s take 30 people with tennis elbow and let’s inject these 30 people with PRP therapy, and let’s follow them for a month and let’s see how they do.” So you’re just looking at this one population, you’re not comparing it to a control population [that receives an injection with placebo]. The thing about doing PRP therapy is that there are potentially other healers going on. Number one is there’s always potential for some type of placebo effect any time you put a needle in anyway. Number two is when you put a needle into a tendon, like you do for PRP therapy, you are likely to cause some bleeding and this is known to help healing [by bringing in more platelets]. So even by sticking a needle in a tendon and aggravating the tendon, you actually are helping the healing response.

Everyone looks at this one study that came out more than a year ago on tennis elbow but the problem is, it was a cohort study. Some people come in, they already know they want it, or there are patients that have failed other treatments. Any time we talk to anyone about PRP treatment, one of the first things that needs to be said is that, right now, there’s not good evidence to support the treatment.

Theoretically, many of the athletes may have a type of tendonitis, [such as] Achilles tendonitis or, say, patellar tendonitis in the knee or tennis elbow. Many of these tendon injuries become chronic, and involve microscopic tearing of the tendon and formation of scar tissue. A reason why it’s difficult to heal these tendon injuries is related to poor blood supply to the region. The perfect example would be the Achilles. It’s a tendon with, in general, a poor blood supply, so when there are these microscopic tears or chronic scarring, the body has a difficult time healing it. The theory is that the body can’t on its own get enough of these healing or growth factors to the area, but now this concentrated platelet injected there just enhances the nutrients and growth factors to allow the body to heal it.

They’ve been runners to basketball players to football players to collegiate competitive cheerleaders, a lacrosse player and a soccer player.