The platelets in your blood have remarkable healing properties. They help your blood to clot when you’re bleeding, and along with plasma, they contain chemicals and growth factors that help repair tissue and joint damage caused by injury.
Platelets are just a tiny part of your blood, but they can be extracted to make a fluid called platelet-rich plasma.
Since the 1970s, doctors have used platelet-rich plasma (PRP) in a variety of ways, from wound healing during heart and dental surgery to cosmetic treatments for reducing wrinkles and stimulating hair growth. If you’re a sports fan, you may have heard professional athletes such as Tiger Woods and Rafael Nadal credit PRP injections for helping them recover from major injuries.
“When we create this hyperconcentrate of platelets and inject it into the body at the place where it’s injured, we tend to see positive results in a large percentage of people,” says UNC Health sports medicine specialist Jill Sylvester, MD.
Some injuries respond better to this treatment than others. We talked to Dr. Sylvester about when PRP injections are an option and what you can expect from the process.
Good Candidates for PRP Injections
PRP injections are recommended after you’ve tried other methods to treat pain, such as physical therapy or exercise modifications.
If physical therapy has helped some, but not enough to help you return to your desired level of activity, your doctor might consider PRP injections. It’s important to note that research on PRP is still evolving and the quality of data is improving.
“Researchers have become more precise with exactly what concentrations they’re using, so I anticipate that we’ll be able to expand what we can use PRP injections for and where we’ll see benefits,” Dr. Sylvester says.
Right now, there’s the most evidence for using PRP injections for knee and hip arthritis, hamstring injuries, tennis elbow, gluteus medius tendinopathy and ulnar collateral ligament injuries (when this ligament in the elbow is completely torn, Tommy John surgery is necessary).
Results are mixed when it comes to PRP injections for ankle and heel injuries and rotator cuff injuries, Dr. Sylvester says.
Your doctor will take your situation into account, including your age, your overall health and the severity of your pain.
“People with mild to moderate pain tend to have better outcomes than people with severe disease, and this isn’t recommended if you have a condition that causes your platelets to not work well, like a bleeding disorder or a history of blood cancer,” Dr. Sylvester says. “Age can also affect the health of your platelets, so younger patients tend to have better outcomes. Still, I’ve had great outcomes with someone who was 90 years old.”
Dr. Sylvester says the youngest patient she’s treated with PRP injections was 14; it’s necessary to wait until all the growth plates are closed, so young children are not eligible.
Willingness and ability to pay is also a factor. PRP injections are not currently approved by the Food and Drug Administration, which means they are not covered by insurance. One injection typically costs $600 or more, depending on where you live.
The PRP Injection Process
If you decide to pursue a PRP injection, your doctor will recommend some preparation before your injection. The injection causes some inflammation as part of the healing, so you’ll be asked to stop anti-inflammatory steroids, nonsteroidal anti-inflammatory drugs (NSAIDs) like ibuprofen, and supplements such as fish oil, turmeric or tart cherry for a week before the injection and two weeks after. You may have to adjust when you take certain blood thinners.
Getting a PRP injection takes about 45 minutes; first, your provider will extract about 60 to 70 cubic centimeters of blood, which is the equivalent of one-fifth a can of soda, Dr. Sylvester says. The blood is then placed into a centrifuge, which separates out the red blood cells that carry oxygen through the body. The spinning takes about 20 minutes, while you wait, and it yields about 5 to 10 cubic centimeters of PRP to use for your injection.
Meanwhile, your doctor will numb the joint or tendon where you’ll receive the injection with anesthesia.
“The anesthesia typically lasts two to six hours, so you have enough time to get home and get comfortable,” Dr. Sylvester says.
Then, your doctor will inject the PRP directly into the joint. For some joints, this one shot may be all you need; in the case of knee arthritis, for example, your doctor may recommend getting a PRP injection combined with a hyaluronic acid shot, which can improve your ultimate outcome.
The injection and resulting inflammation can cause mild pain for a few days after the injection, which most people manage with Tylenol, but there aren’t many other side effects.
“We’re using a person’s own body products to treat disease, so there’s little risk of a reaction,” Dr. Sylvester says. “Any time you break the skin with a needle, there’s a risk of pain, bleeding and infection, but these risks are low.”
When PRP injections are used for osteoarthritis, it can take six weeks to see results.
“For the first two weeks, we want people to rest the joint that was injected,” Dr. Sylvester says. “You can go to the grocery store, but you shouldn’t do a lot of exercise. The second two weeks, you can start some non-impact exercise, like swimming or biking. Those final two weeks, you can usually start to get back to your regular routine.”
For osteoarthritis, the pain-relieving effects of a PRP injection typically last six months to a year and injections can be repeated.
Injured tendons can take longer to heal; it may take as long as 10 to 12 weeks for the tendon to fully heal and feel better. The good news: if your tendon fully heals, you don’t need additional treatment, but physical therapy will continue to be helpful to strengthen the area.
The goal of a PRP injection is to help you resume activity in a pain-free way, but it’s important to manage your expectations.
“If your goal is to ride your bike for 40 minutes every day, that’s achievable,” Dr. Sylvester says. “If your goal is to play in the NBA, remember that elite athletes are doing rehab for multiple hours a day. They’re doing a lot more than PRP injections.”
If you’re experiencing joint pain, talk to your doctor. If you need a doctor, find one near you.