Updated: Jul 14
THE INJECTION SERIES:
PRP injections for Achilles tendinopathy (this article)
PRP (platelet-rich plasma) injections are an effective treatment for tendon injuries such as tennis elbow and patellar tendinopathy. However, the jury is still out on whether they work for Achilles tendinopathy.
The terms tendinitis, tendonitis, tendinosis, and tendinopathy mean the same thing for all practical purposes, and we use these interchangeably in our articles.
In this article:
Here's a video I made about it:
Why do they use PRP injections?
PRP is made by drawing some of the patient’s blood and then spinning it to separate it into different layers. The plasma layer, containing a high concentration of platelets, is then drawn off and injected into the injury.
Highly concentrated platelets can release a large number of growth factors, which in turn can stimulate healing. Achilles tendinopathy is seen as a degenerative process where healing has failed and the aim with these injections is to kick-start the collagen regeneration and healing process. It also has the ability to dull pain (usually after first increasing it for a few days!)
Do PRP injections work for Achilles tendinopathy?
PRP has been shown to be very effective as treatment for tennis elbow, osteoarthritis of the knee, patellar tendinopathy as well as plantar fasciitis. But unfortunately the current research does not support its use for Achilles tendinopathy.
Four recent literature reviews and meta-analyses that looked at all the studies on PRP injections for Achilles tendinopathy vs. other treatments or placebo injections found no extra benefit from adding PRP to the treatment regimes.
PRP may still be found to be useful for Achilles tendinopathy
The problem with the current research is that there’s no standardized protocol for preparing PRP or even for injecting it. This means that the quality of the PRP preparation can vary dramatically between studies and even between injections done on the same patient.
There are more than 16 different types of machine for preparing the PRP, and each one of them produces different concentrations of platelets. Some clinicians prefer to spin the preparation once, while others spin it twice. The analgesic that they sometimes inject before they do the PRP injection has also been shown to decrease platelet function, and once again, clinicians use varying amounts of this when they do these injections.
The patient’s own health status can affect the number and quality of blood platelets they have. Physical as well as mental stress have been shown to affect how the platelets release their bioactive compounds. Diets containing caffeine, quercetin (a flavonoid present in high levels in onions, apples, tea, and wine) and isoflavones (present in legumes) can reduce platelet activation.
These are only some of the main things that may affect the quality of the PRP preparation – the list is actually a lot longer! This is why I am hesitant to permanently close the door on PRP and Achilles tendinopathy. I feel that there is a lot of evidence from similar research done on other tendons that shows that PRP can be useful, and from the above it's obvious that there is a lot of scope still to refine the technique for Achilles tendons.
It would not be my first choice of treatment, but I would consider recommending it for someone who has not reacted to a well-structured rehab programme.
How we can help
Need more help with your Achilles injury? You’re welcome to consult one of the team at TMA online via video call for an assessment of your injury and a tailored treatment plan.
We're all UK Chartered Physiotherapists with Master’s Degrees related to Sports & Exercise Medicine. But at Treat My Achilles we don't just value qualifications; all of us also have a wealth of experience working with athletes across a broad variety of sports, ranging from recreationally active people to professional athletes. You can meet the team here.
About the Author
Fitzpatrick, J., et al. (2017). "The effectiveness of platelet-rich plasma in the treatment of tendinopathy: a meta-analysis of randomized controlled clinical trials." The American Journal of Sports Medicine 45(1): 226-233.
Lin, M.-T., et al. (2018). "Meta-analysis comparing autologous blood-derived products (including platelet-rich plasma) injection versus placebo in patients with Achilles tendinopathy." Arthroscopy: The Journal of Arthroscopic & Related Surgery 34(6): 1966-1975. e1965.