title: Effect of platelet-rich plasma on tendon-to-bone healing after rotator cuff repair in rats: an in vivo experimental study.
abstract: OBJECTIVE
  The purpose of this experimental study was to analyze the effects of local autologous platelet-rich plasma (PRP) injection on tendon-to-bone healing in a rotator cuff repair model in rats.
  
  
  METHODS
  Rotator cuff injury was created in 68 left shoulders of rats. PRP was obtained from the blood of an additional 15 rats. The 68 rats were divided into 4 groups with 17 rats in each group; PRP group (Week 2), control group (Week 2), PRP group (Week 4), and control group (Week 4). Platelet-rich plasma or saline was injected to the repair area intraoperatively. Rats were sacrificed 2 and 4 weeks after the surgery. Histological analysis using a semiquantitative scoring was performed on 7 rats per group. Tendon integrity and increases in vascularity and inflammatory cells and the degree of new bone formation were evaluated and compared between the groups. The remaining tendons (n=10) were mechanically tested.
  
  
  RESULTS
  Degree of inflammation and vascularity were less in the study group at both time intervals (p<0.05). Tendon continuity was better in the study group at 2 weeks (p<0.05). Obvious new bone formation was detected in the control group at 4 weeks (p<0.05). Biomechanically, platelet-rich plasma-treated specimens were stronger at 2 weeks (p<0.05).
  
  
  CONCLUSIONS
  Local autologous PRP injection may have beneficial effects on initial rotator cuff tendon-to-bone healing and enhance initial tendon-to-bone healing remodeling. This may represent a clinically important improvement in rotator cuff repair.
authors.affiliation: Department of Orthopedics and Traumatology, Faculty of Medicine, Dokuz Eylül University, İzmir, Turkey. onurhapa@gmail.com
authors.forename: Onur
authors.initials: O
authors.lastname: Hapa
authors.forename: Hüsamettin
authors.initials: H
authors.lastname: Cakıcı
authors.forename: Aysel
authors.initials: A
authors.lastname: Kükner
authors.forename: Hayati
authors.initials: H
authors.lastname: Aygün
authors.forename: Nazlı
authors.initials: N
authors.lastname: Sarkalan
authors.forename: Gökhan
authors.initials: G
authors.lastname: Baysal
mesh_terms: D000818:Animals; D004195:Disease Models, Animal; D005500:Follow-Up Studies; D007267:Injections; D007432:Intraoperative Period; D008297:Male; D053657:Platelet-Rich Plasma; D051381:Rats; D017207:Rats, Sprague-Dawley; D019651:Plastic Surgery Procedures; D017006:Rotator Cuff / Q000473:pathology / Q000601:surgery; D000070636:Rotator Cuff Injuries; D013708:Tendon Injuries / Q000473:pathology / Q000628:therapy*; D014945:Wound Healing