Autologous Platelets Have No Effect on the Healing of Human Achilles Tendon Rutures:  A Randomized Single-Blind Study
Schepull T, Kvist J, Norrman H, Trinks M, Berlin G, Aspenberg P.  Am J Sports Med. 2011 39(1):  38-47. 

In the past few years platelet rich plasma (PRP) injections have taken the scene in sports medicine for treatment of both acute and chronic injuries.  PRP use skyrocketed when several high-profile professional athletes used this new therapy to try to accelerate healing and decrease the amount of time out of play.  Many people perceive PRP as the answer to all injuries for returning athletes to the field faster, however there is minimal research investigating the true effect it has on the rate and effectiveness of tissue healing. This study was one of the first randomized single-blind studies investigating the effectiveness of PRPs on Achilles tendon healing in patients.  Thirty patients with an acute rupture of their Achilles tendon were recruited.  PRPs were prepared from the patient’s own blood the day prior to surgery.  Standard surgical procedures were followed for the repair of the Achilles tendon: the tendon was then sutured to the anatomic footprint and PRP was randomly injected at the location of the repositioned tear in half of the patients.  Standard treatment and rehabilitation was followed after surgery for both groups.  Testing consisted of determining the elastic modulus (the amount of elastic deformation a tissue experiences at a certain load) and follow-up functional outcome measures: passive range of motion, calf circumference, heel raise index (incorporates the number of single-limb toe raises and the maximum height of the single-limb toe raise), force development calculated from gait analysis and a vertical jump, and the Achilles Tendon Total Rupture Score (ATRS).  They found that there were no group differences for elastic modulus and heel raise index.  The ATRS was lower in the PRP group, suggesting a worse functional outcome. 

This study was the first to systematically test the effectiveness of PRP injections for Achilles tendon healing in a randomized single-blind study.  With the popularity of this treatment and no strong scientific data either refuting it or supporting it more studies like this are required.  This study did not find any mechanical differences to the healing tendon or any functional improvements between groups.  In fact, the ATRS actually indicated that the PRP group had a lower functional outcomes.  While this study indicated that PRP injections may not be effective for acute Achilles tendon injuries PRP may have successful results at other locations like the shoulder, knee, or elbow.  There is some interesting research using PRP to promote ACL tear healing in addition to rotator cuff tears and lateral epicondylitis.  Currently I would caution recommending this therapy for treating acute injuries based on this study and the theoretical mechanism of PRP.  Acute injuries should have a large amount of platelets at the injury site and therefore adding more may not improve healing.  Chronic injuries, on the other hand, are lacking platelets at the injury site and therefore may respond positively to the application of platelets.  Then again the patient may improve just because of the tissue damage associated with the needle passing through the injured tissue.  Prolotherapy which is the repetitive needling at the site of injury without injection of any substance aside from Novocain has been effectively used to treat lateral epicondylitis symptoms.  Therefore the question still remains whether PRP will stand the test of time and be a treatment that can be used to accelerate the healing of common orthopaedic soft tissue injuries. 

Written by: Stephen Thomas
Reviewed by: Jeffrey Driban