One-year Follow-up of Platelet-Rich Plasma Treatment in Chronic Achilles Tendinopathy: A Double-Blind Randomized Placebo-Controlled Trial.
de Jonge S, de Vos RJ, Weir A, van Schie HT, Bierma-Zeinstra SM, Verhaar JA, Weinans H, Tol JL. Am J Sports Med. 2011 May 21. [Epub ahead of print]
In February, SMR had a post describing a randomized trial that found platelet-rich plasma (PRP) injections do not improve acute Achilles tendon healing. In the post it was suggested that PRP injections may be beneficial for chronic injuries. Achilles tendinopathy is a common condition that PRP injections are sometimes advocated but good evidence for this practice is lacking. Therefore, de Jonge et al conducted a double-blind randomized controlled trial to evaluate the effects of a PRP injection in 54 patients (age 26 to 70 years) with chronic midportion Achilles tendinopathy at 1-year follow-up. This study represents a longer follow up to a paper that reported PRP injections had no additional benefits 6, 12, or 24 weeks after the injection. Patients received an ultrasound-guided 4-mL PRP injection or a 4-mL saline injection (using 3 different needle locations). After the injection, patients avoided sports activities for 4 weeks, in the second week they performed stretching exercises, and then they started a 12-week program of eccentric exercises. The main outcome was a validated questionnaire for Achilles tendinopathy. Ultrasonography was also conducted to evaluate the tendon structure. After 24 weeks, 4 patients in the PRP group sought another treatment while only 1 person in the placebo group sought an alternative treatment. Neither group had any adverse outcomes associated with the injections. Both groups had better clinical and ultrasonographic outcomes at 1 year compared to baseline. After 1 year both groups had similar changes in clinical outcomes as well as similar patient satisfaction, and number of patients return to sports. There were also no significant differences between groups based on ultrasound finding (e.g., maximum anterior-posterior diameter change, neovascularization). Based on the data, the authors conclude that the trial showed no clinical or ultrasonographic superiority of PRP injections compared to placebo (both in conjunction with eccentric training) among patients with chronic Achilles tendinopathy after 1 year.
This is another randomized-clinical trial that casts doubt on the use of PRP for Achilles tendons. It is important to keep in mind that this study does not answer questions about other anatomical sites or about patient populations under the age of 26 years. Other clinical trials like this one will be needed to better address those questions. On the plus side, this study found no adverse events associated with the injections. Based on the data, I would not advocate PRP injections for Achilles tendons unless other treatments have failed. After all 59% patients receiving PRP or placebo injections in conjunction with an eccentric training program reported positive patient satisfaction and at least we know that the risks of adverse events are low; perhaps taking advantage of the placebo effect would not hurt either. What are your experiences with PRP injections?
Written by: Jeffrey Driban
Reviewed by: Stephen Thomas