title: Platelet-rich plasma injection for chronic Achilles tendinopathy: a randomized controlled trial.
abstract: BACKGROUND
  Tendon disorders comprise 30% to 50% of all activity-related injuries; chronic degenerative tendon disorders (tendinopathy) occur frequently and are difficult to treat. Tendon regeneration might be improved by injecting platelet-rich plasma (PRP), an increasingly used treatment for releasing growth factors into the degenerative tendon.
  
  
  OBJECTIVE
  To examine whether a PRP injection would improve outcome in chronic midportion Achilles tendinopathy.
  
  
  METHODS
  A stratified, block-randomized, double-blind, placebo-controlled trial at a single center (The Hague Medical Center, Leidschendam, The Netherlands) of 54 randomized patients aged 18 to 70 years with chronic tendinopathy 2 to 7 cm above the Achilles tendon insertion. The trial was conducted between August 28, 2008, and January 29, 2009, with follow-up until July 16, 2009.
  
  
  METHODS
  Eccentric exercises (usual care) with either a PRP injection (PRP group) or saline injection (placebo group). Randomization was stratified by activity level.
  
  
  METHODS
  The validated Victorian Institute of Sports Assessment-Achilles (VISA-A) questionnaire, which evaluated pain score and activity level, was completed at baseline and 6, 12, and 24 weeks. The VISA-A score ranged from 0 to 100, with higher scores corresponding with less pain and increased activity. Treatment group effects were evaluated using general linear models on the basis of intention-to-treat.
  
  
  RESULTS
  After randomization into the PRP group (n = 27) or placebo group (n = 27), there was complete follow-up of all patients. The mean VISA-A score improved significantly after 24 weeks in the PRP group by 21.7 points (95% confidence interval [CI], 13.0-30.5) and in the placebo group by 20.5 points (95% CI, 11.6-29.4). The increase was not significantly different between both groups (adjusted between-group difference from baseline to 24 weeks, -0.9; 95% CI, -12.4 to 10.6). This CI did not include the predefined relevant difference of 12 points in favor of PRP treatment.
  
  
  CONCLUSIONS
  Among patients with chronic Achilles tendinopathy who were treated with eccentric exercises, a PRP injection compared with a saline injection did not result in greater improvement in pain and activity.
  
  
  BACKGROUND
  clinicaltrials.gov Identifier: NCT00761423.
authors.affiliation: Department of Orthopedics, Room Ee1614, Erasmus University Medical Center, PO Box 2040, Dr Molenwaterplein 50, 3000 CA Rotterdam, The Netherlands. r.devos@erasmusmc.nl
authors.forename: Robert J
authors.initials: RJ
authors.lastname: de Vos
authors.forename: Adam
authors.initials: A
authors.lastname: Weir
authors.forename: Hans T M
authors.initials: HT
authors.lastname: van Schie
authors.forename: Sita M A
authors.initials: SM
authors.lastname: Bierma-Zeinstra
authors.forename: Jan A N
authors.initials: JA
authors.lastname: Verhaar
authors.forename: Harrie
authors.initials: H
authors.lastname: Weinans
authors.forename: Johannes L
authors.initials: JL
authors.lastname: Tol
mesh_terms: D000125:Achilles Tendon; D000328:Adult; D004311:Double-Blind Method; D005081:Exercise Therapy; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010147:Pain Measurement; D053657:Platelet-Rich Plasma; D052256:Tendinopathy / Q000628:therapy*; D016896:Treatment Outcome