Many of you, I’m sure, will be interested to learn to efficacy of PRP injections for treating athletes with chronic achilles tendinopathies. PRP has gained significant attention of late; in the media, medical community and with our athletes. It seems my athletes are always asking for information on the most effective form of injectional therapy for their conditions… “Do you think blood injections will help?”.
My main issue with recommending PRP injectional therapy is the lack of sound evidence regarding its effectiveness (Paoloni et al, 2011). Whilst there have been various low quality trials examining the use of PRP in acute tendon, acute ligament and chronic tendon presentations in both animal and human subjects, the results are conflicting (Paoloni et al, 2011).
Fortunately, a recent study provides some light on the use of PRP in a chronic Achilles tendinopathy group (de Vos et al, 2010).
JUST WHAT ARE PLATELET-RICH PLASMA (PRP) INJECTIONS?
Plate-rich plasma (PRP) is plasma with a high concentration of platelets, which is derived from centrifuging whole blood (Marx et al, 2001). The platelet-rich plasma is what settles following the centrifuging process, and contains numerous growth factors. Thus, it is hypothesised that injection of this highly concentrated ‘growth cocktail’ into injured tissues may assist with both the inflammatory cascade and regenerative processes (Marx et al, 2001).
As you might expect, this is a simplification of the mechanisms through which PRP is proposed to act. If you wish for a more in-depth examination of PRP I implore you to seek out further information from the references provided.
THE BASIC SCIENCE OF PRP (VIDEO)
PLATELET-RICH PLASMA (PRP) INJECTIONS AND CHRONIC ACHILLES TENDINOPATHY
De Vos et al (2010) randomised 54 athletes into two groups; one group underwent a single PRP injection into multiple depots under the guidance of Doppler ultrasound (n=27) and the other group underwent a ‘placebo’ saline injection (n=27). Both groups then commenced the ‘usual treatment’ of an eccentric exercise program. The study showed improvements in both groups, however there was no significant differences between outcome measures of pain, function (VISA-A) within a 6-month follow-up period or return to play at 12 weeks (57%).
Unfortunately, there are a few valid criticisms of the current study. It seems that the clinical generalisability of the current study is questionable. It has been suggested that PRP therapies are indicated following failure of physiotherapy and conservative measures (Sanchez et al, 2009). I would suggest this would reflect current widespread physiotherapy practice, in which injectional therapies would only be considered if our conservative treatments had failed. However, in this study the injections were given prior to the commencement of an eccentric exercise program. Therefore, we cannot examine the benefits of the PRP injections alone. Also, it is impossible to know which population the treatment is most effective.
The other important point to consider is the side-effects of PRP therapy, which many studies fail to report (Paoloni et al, 2011). The PRP injections hurt, apparently a lot (ask anyone who has had them). Generally there is increased pain and stiffness for a few days following (Kon et al, 2009), which will require rest from training or play. Therefore, it can be a challenging task to time the injections i.e. when the athlete can have time off.
TAKE HOME MESSAGES
- The current RCT provides no evidence to support the use of PRP as a first contact treatment in chronic Achilles tendinopathy
- PRP may be better indicated in chronic Achilles tendinopathies which fail to respond to other conservative measures, although this is yet to be examined.
- The classic questions of narrative remain unanswered about the use of PRP – who, what, when, why, how?
- Who is it best indicated for?
- What conditions?
- When in the rehabilitation process?
- How many injections and depots?
- Why PRP over other injectional therapies (e.g. prolotherapy, corticosteroid)?
What has been your experience with the use of PRP? Have you have successes with its use? I am sure that they are many anecdotal successes with its use… let me know in the comments or catch me on Facebook or Twitter
De Vos RJ, Weir A, van Schie HTM, et al. Platelet-rich plasma injection for chronic Achilles tendinopathy: a randomised controlled trial. JAMA. 2010;303:144–149.
Kon E, Filardo G, Delcogliano M, et al. Platelet-rich plasma: new clinical application. A pilot study for treatment of jumper’s knee. Injury. 2009;40: 598–603.
Marx RE. Platelet-rich plasma (PRP): what is PRP and what is not PRP? Implant Dent. 2001;10:225–228.
Paoloni J, De Vos RJ, Hamilton B, Murrel GAC, DPhil §, Orchard J. Platelet-Rich Plasma Treatment for Ligament and Tendon Injuries. Clin J Sport Med 2011;21:37–45
Sanchez M, Anitua E, Orive G, et al. Platelet-rich therapies in the treatment of orthopaedic sport injuries. Sports Med. 2009;39:345–354.