Are PRP (platelet-rich plasma) injections worth it for joint pain? Photo by RF._.studio
Osteoarthritis, labral tears, and cartilage and tendon pain can all prompt doctors to prescribe platelet-rich plasma injections. Here’s why you should consider functional movement training first.
I work with a lot of clients who have had chronic hip, knee, back, and shoulder pain. They have usually spent all kinds of money and time trying to fix their aches and pains with massage, chiropractic work, physical therapy, dry-needling, acupuncture, and more. When those approaches fail to help, people often get desperate. And that’s when platelet-rich plasma, or PRP, injections pop up on the radar.
The premise of PRP injections is that all you need to do is pull some blood out of your body, make it richer in platelets by spinning it around, and then inject that super-charged blood back into your body so it can promote faster healing. This sounds both high-tech and easy. And if a doctor suggests it, it must work, right?
As a functional movement trainer who focuses on muscle balance and proper movement patterns, I’m generally not a huge fan of PRP injections. Here’s why:
In short, if you believe that the only one who can fix your problems is someone else, you’re in for a very long and frustrating road. If you instead start with the assumption that there’s something YOU can do to positively affect your situation, you will be much better off.
That means avoiding pain treatment strategies that imply that your body is damaged beyond all normal human healing capacity.
You may be saying “But I have arthritis, a labral tear, or some other major issue with my body.”
Okay, but science shows that alleged structural problems like arthritis and labral tears are rarely linked to pain. There’s a whole lot more going on when you experience pain than tissue damage.
There are two main reasons doctors sell PRP injections to their patients.
One is for persistent pain that they blame on soft tissues (like muscles or tendons). The second is for joint degeneration (like arthritis, chondral lesions, and cartilage loss).
When you have pain in a muscle, tendon, or ligament, doctors may suggest that this is due to damage in the soft tissue itself. If it continues to hurt for a long period of time, they may suggest that the soft tissue is having trouble healing and by injecting platelet-rich plasma into the site, you’ll increase the speed at which the soft tissue heals.
This would be fantastic! Imagine the implications for healing after an injury or a surgery. ACL torn? Achilles ruptured? Hamstring torn? A PRP injection may be all you need to speed up that healing process!
In fact, lab experiments on muscles and tendons indicate that PRP may actually speed up healing in these tissues, but also have the reverse effect on ligaments. It’s all quite murky.
A 2014 research review of 19 small studies on PRP injections concluded that there wasn’t sufficient evidence to support platelet-rich therapies for treating musculoskeletal soft tissue injuries.
A more recent research review of PRP research, published in 2017, concluded that PRP may provide some benefit in patients who have knee osteoarthritis and lateral epicondylitis, but inconsistent and minimal benefits for rotator cuff repairs, patellar and Achilles tendinopathies, hamstring injuries, ACL repairs, and medial epicondylitis.
It seems that PRP injections are just not that useful for pain that allegedly comes from soft tissue damage.
A pair of naked knees. Photo by Karolina Grabowska
So PRP for soft tissue seems to be a non-starter. But what about PRP injections for arthritis?
There is some evidence that PRP injections might be helpful for knee arthritis. One of the very best studies available on PRP for knee osteoarthritis, published in 2013 in the American Journal of Sports Medicine, compared PRP injections to placebo saline injections.
They found that the groups of patients receiving PRP injections did better than the group that received saline injections. They also found that the positive results started to diminish at the six month follow up. And since there was no follow up after six months, nobody knows how they did in the long-term.
Many new-fangled orthopedic treatments go through this same lifecycle. Someone introduces it to the market. For years, it's difficult to find any high-quality studies. Then after many more years, it's hard to find any long-term studies to demonstrate lasting benefit.
By the time anyone gets around to doing high-quality, long-term studies, the treatment is already so popular that everyone believes it works (even if it is no better than placebo). The same pattern exists with knee meniscus surgery, for example.
But there’s a much larger question to address when thinking about PRP for arthritis: Does arthritis really cause joint pain?
This may sound silly, but it’s a crucial question. Conventional medical approaches to pain assume one thing: Pain means damage–if there is pain in the joint, it means joint damage.
And what is joint damage? Osteoarthritis.
The conventional story is simple: Your bones are degenerating as they rub against each other, and this causes pain. You can verify this in an x-ray. However, research consistently shows that the severity of arthritis in an x-ray has no link at all to the experience of pain.
Put another way, you can show bone-on-bone, grade four osteoarthritis in an x-ray, and have no symptoms. The same is true for cartilage damage, labral tears, and tendon damage–x-rays that show damage can’t be linked directly to the experience of pain. Research shows that you can have no signs of arthritis in an x-ray and still have symptoms of pain and immobility. You can have a lot of arthritis and have no complaints at all!
Let's repeat that one more time: Even if you have terrible, awful, grade four osteoarthritis in an x-ray, you may actually experience ZERO symptoms. And on the opposite side of the same coin, you can have zero signs of arthritis in an x-ray, and still have symptoms of pain and immobility.
No, I'm not just making this up.
Researchers have done multiple studies on knee osteoarthritis in thousands of people and found that there is no link between the severity of arthritis shown on an x-ray and actual knee pain.
And again, a significant percentage of people with completely asymptomatic, pain-free knees show signs of knee osteoarthritis on x-rays. The numbers are actually huge.
For example, a 2017 study published in the British Journal of Sports Medicine found that in asymptomatic adults under 40, 4 percent to 14 percent show signs of knee osteoarthritis. In the over 40 population, 19 percent to 43 percent show signs of knee osteoarthritis.
Let me help you demystify the way scientific studies can create a false perception of efficacy. This way you won’t be tempted to simply accept the associations that are presented as the truth, when, in fact, the causation of both pain and healing are not clear.
Let’s look at an analogy. Assume 25 percent of adults over the age of 40 drink soda in the United States. Let's say we suspect soda drinking is what causes knee problems.
Now let’s do some research studies. Assume your first study sample looks like this:
Is soda the cause of their knee problems? We can't say that it is.
Let’s do another study with a different set of random people:
Is soda the cause of their knee problems? You might be tempted to say that more people with knee pain drink soda. But that doesn’t mean it’s the soda causing the knee pain. There might be some correlation, but it's unclear why.
Remember the old adage “Correlation does not equal causation."
After all, in another study, you could discover this:
The numbers can fluctuate simply from the randomness of the individuals in the groups. You have to be able to reproduce your numbers to be sure that your conclusions are sound!
If the soda is actually the cause of the knee problems, you'd expect to see something like this:
This looks pretty convincing, right? But here’s the thing. Even with numbers like this, you wouldn't have a slam dunk case! There could be some other variable you don't realize is affecting things. Maybe people who drink soda are less likely to exercise? Or maybe they're more likely to participate in activities like soccer and football that can potentially be more strenuous on the knees? You have to test rigorously to figure out what variables matter, EVEN IF one variable LOOKS like it might be causing an issue.
One way to investigate more thoroughly is to look at large groups of people with and without symptoms to see if the variable you suspect is actually causing the problem. If you see some dramatic differences in the numbers, you have the beginning (AND ONLY THE BEGINNING) of a case.
The big problem related to research on arthritis and PRP injections is that researchers don’t dig deep enough before claiming they know what causes joint pain!
If they see a correlation between pain and ”damage” on an x-ray, they say it’s the cause! They see correlation and then claim causation.
Watch this video to learn what doctors won’t tell you about hip pain and hip arthritis:
But research just doesn’t support that position. Many research papers claim that arthritis causes various kinds of joint pain, but they completely ignore the fact that the asymptomatic population also regularly shows signs of “damage” in x-rays and MRIs.
In short, you have signs of “damage” that have no correlation to the experience of pain.
This isn’t isolated to just knee arthritis, of course. All kinds of allegedly iron-clad orthopedic theories about structural damage causing pain don’t hold up. Here are more relevant studies:
The problem is that everyday people like you and me don’t usually have the time to dig deeper into the research to see what’s going on. Truth be told, physicians often don’t have the time to dig into the research either!
That’s why myths like “pain means damage” persist.
And that’s why doctors continue to prescribe PRP injections for arthritis and more. Even if PRP injections show some limited short-term benefit, they are still focused on "damage" that may not actually be the cause of your problems.
Learn why your knees hurt as you age and exercises to fix your knee pain:
As you can see, the research on PRP injections for pain isn’t great. There are very few high-quality studies demonstrating any positive benefit from PRP injections for soft tissue issues.
There are no high-quality studies that show long-term positive benefits from PRP injections. And, the studies that show some short-term benefits for things like knee arthritis are based on a set of beliefs that do not hold up under closer scrutiny.
My suggestion to anyone dealing with chronic, persistent, and stubborn pain?
Reframe the problem. Look closely at how you use your body. Train it to move better in a variety of ways. This is a safe approach with few (if any) negative side effects. The only downside is that it takes time, patience, and lifestyle changes.
This is how I have overcome my own pain issues. It’s how I teach my clients to overcome theirs.
Remember, in functional training, we’re always thinking about solutions through muscle strength and balance. These movement-based strategies are generally more effective than turning to the conventional protocols for rest, ice, injections, pills, and surgery (what I call RIIPS).