title: Use of autologous platelet-rich plasma to treat muscle strain injuries.
abstract: BACKGROUND
  Standard nonoperative therapy for acute muscle strains usually involves short-term rest, ice, and nonsteroidal anti-inflammatory medications, but there is no clear consensus on how to accelerate recovery.
  
  
  OBJECTIVE
  Local delivery of platelet-rich plasma to injured muscles hastens recovery of function.
  
  
  METHODS
  Controlled laboratory study.
  
  
  METHODS
  In vivo, the tibialis anterior muscles of anesthetized Sprague-Dawley rats were injured by a single (large strain) lengthening contraction or multiple (small strain) lengthening contractions, both of which resulted in a significant injury. The tibialis anterior either was injected with platelet-rich plasma, was injected with platelet-poor plasma as a sham treatment, or received no treatment.
  
  
  RESULTS
  Both injury protocols yielded a similar loss of force. The platelet-rich plasma only had a beneficial effect at 1 time point after the single contraction injury protocol. However, platelet-rich plasma had a beneficial effect at 2 time points after the multiple contraction injury protocol and resulted in a faster recovery time to full contractile function. The sham injections had no effect compared with no treatment.
  
  
  CONCLUSIONS
  Local delivery of platelet-rich plasma can shorten recovery time after a muscle strain injury in a small-animal model. Recovery of muscle from the high-repetition protocol has already been shown to require myogenesis, whereas recovery from a single strain does not. This difference in mechanism of recovery may explain why platelet-rich plasma was more effective in the high-repetition protocol, because platelet-rich plasma is rich in growth factors that can stimulate myogenesis.
  
  
  CONCLUSIONS
  Because autologous blood products are safe, platelet-rich plasma may be a useful product in clinical treatment of muscle injuries.
authors.affiliation: Union Memorial Hospital, Department of Orthopedic Surgery, Baltimore, Maryland, USA.
authors.forename: Jason W
authors.initials: JW
authors.lastname: Hammond
authors.forename: Richard Y
authors.initials: RY
authors.lastname: Hinton
authors.forename: Leigh Ann
authors.initials: LA
authors.lastname: Curl
authors.forename: Joaquin M
authors.initials: JM
authors.lastname: Muriel
authors.forename: Richard M
authors.initials: RM
authors.lastname: Lovering
mesh_terms: D000818:Animals; D001804:Blood Transfusion, Autologous; D015153:Blotting, Western; D007273:Injections, Intramuscular; D008297:Male; D018482:Muscle, Skeletal / Q000293:injuries*; D053657:Platelet-Rich Plasma; D051381:Rats; D017207:Rats, Sprague-Dawley; D020127:Recovery of Function / Q000502:physiology; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013180:Sprains and Strains / Q000503:physiopathology / Q000534:rehabilitation / Q000628:therapy*; D016896:Treatment Outcome