Major Finding: Patients with chronic midportion Achilles tendinopathy received no benefit from injections of platelet-rich plasma (PRP).
Data Source: In a blinded, randomized, placebo-controlled trial, 27 patients were treated with PRP injections and 27 were treated with placebo injections.
Disclosures: Funded by Biomet Biologics. No other disclosures were reported.
Injections of platelet-rich plasma failed to improve pain or function in the first blinded, randomized placebo-controlled trial of the new technique for Achilles tendinopathy, results from a small study suggest.
The treatment also delivered no more patient satisfaction than placebo injections, nor did it facilitate a return to sports activity.
“These findings are important and clinically relevant as PRP is thought to be growing in popularity, and recent reviews supported its use for chronic tendon disorders,” said Dr. Robert J. de Vos of Erasmus University Medical Center, Rotterdam, the Netherlands, and his associates (JAMA 2010;303:144–9).
Platelet-rich plasma injections “raised high expectations” when they were introduced because PRP contains several growth factors that are known to play a role in tissue repair.
It was thought that relatively high concentrations of vascular endothelial growth factor, platelet-derived growth factor, and transforming growth factor–beta could help regenerate tendon tissue “through increased tendon cell proliferation, collagen synthesis, and vascularization.”
In their trial, Dr. de Vos and his colleagues compared PRP injections with placebo injections in 54 patients who were treated at the sports medicine outpatient department of a single large hospital for chronic midportion Achilles tendinopathy.
The pain was located approximately 2–7 cm proximal to the tendon's insertion on the calcaneus.
The tendon structure was examined using ultrasound, and the fluid was injected through three puncture locations. Five small depots were left at each location, within the degenerative area of the main body of the tendon.
All subjects underwent a standard rehabilitation program that included daily stretching and eccentric exercises—primarily “heel drops” performed on a step, which stretched the Achilles tendon while concurrently contracting the calf muscle.
At 6, 12, and 24 weeks' follow-up, scores were no different between the 27 patients who received active injections and the 27 who received placebo injections, on a measure of pain and activity specifically addressing Achilles tendinopathy.
Subjective patient satisfaction also was not significantly different between the two groups, according to the results. The same was true for the number of subjects able to return to their desired sport after 24 weeks.
The use of PRP injections in clinical practice has been based on the findings of laboratory studies and a few small clinical studies that did not include a proper control group and were not blinded, Dr. de Vos and his associates noted.
Given the results of their clinical trial, “we do not recommend this treatment for chronic midportion Achilles tendinopathy,” they said.