title: The effect of platelet-rich plasma on Achilles tendon healing in a rabbit model.
abstract: OBJECTIVE
  The aim of the present study was to evaluate the effects of PRP on Achilles tendon healing in rabbits during the inflammatory, proliferative, and remodeling phases by histological examination and quantitative assessments.
  
  
  METHODS
  Fifty mature male Japanese albino rabbits with severed Achilles tendons were divided into two equal groups and treated with platelet-rich plasma (PRP) or left untreated. Tendon tissue was harvested at 1, 2, 3, 4, and 6 weeks after treatment, and sections were stained with hematoxylin-eosin and monoclonal antibodies against CD31 and type I collagen.
  
  
  RESULTS
  Collagen fibers proliferated more densely early after severance, and subsequent remodeling of the collagen fibers and approximation of normal tendinous tissue occurred earlier in the PRP group than in the control group. The fibroblast number was significantly higher in the PRP group than in the control group at 1 and 2 weeks. Similarly, the area ratio of CD31-positive cells was significantly higher in the PRP group than in the control group at 1 and 2 weeks. Positive staining for type I collagen was more intense in the PRP group than in the control group after 3 weeks, indicating tendon maturation.
  
  
  CONCLUSIONS
  Administration of PRP shortened the inflammatory phase and promoted tendon healing during the proliferative phase.
authors.affiliation: Department of Orthopedic Surgery, Osaka Medical College, Osaka, Japan. Electronic address: masaki_takamura75@yahoo.co.jp.
authors.forename: Masaki
authors.initials: M
authors.lastname: Takamura
authors.affiliation: Department of Orthopedic Surgery, Osaka Medical College, Osaka, Japan.
authors.forename: Toshito
authors.initials: T
authors.lastname: Yasuda
authors.affiliation: Department of Orthopedic Surgery, Osaka Medical College, Osaka, Japan.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Nakano
authors.affiliation: Department of Orthopedic Surgery, Osaka Medical College, Osaka, Japan.
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Shima
authors.affiliation: Department of Orthopedic Surgery, Osaka Medical College, Osaka, Japan.
authors.forename: Masashi
authors.initials: M
authors.lastname: Neo
mesh_terms: D000125:Achilles Tendon / Q000293:injuries / Q000473:pathology / Q000503:physiopathology; D000818:Animals; D004195:Disease Models, Animal; D007150:Immunohistochemistry; D008297:Male; D019637:Orthopedic Procedures / Q000379:methods*; D053657:Platelet-Rich Plasma; D011817:Rabbits; D012038:Regeneration / Q000187:drug effects*; D012421:Rupture / Q000503:physiopathology / Q000628:therapy; D013708:Tendon Injuries / Q000503:physiopathology / Q000628:therapy; D016896:Treatment Outcome
keywords: Achilles tendon; Growth factor; Platelet-rich plasma; Rabbit; Tendon healing