Platelet rich plasma is now being used worldwide for tendon related injuries and disorders. Increased vascularity is one of the proposed mechanism of action for PRP. In the study outlined below, this hypothesis is supported in an achilles tendon injury model.
The poor vascularity of tendons is a major factor in their limited healing capacity. The aim of this study was to assess the effect of Platelet Rich Plasma (PRP) on angiogenesis during tendon healing. MATERIALS AND METHODS: Forty-eight skeletally mature New Zealand White rabbits were used. The Achilles tendon was transected transversely and 0.5 ml of PRP was injected into the tendon mass on each side of the incision on both limbs. The injection in the control group consisted of saline. Six animals from each group (12 tendons each) were sacrificed after 1, 2, 3, and 4 weeks following treatment. Three sections from each Achilles were stained with hematoxylinosin for microscopic examination. Further three sections were immunostained with a monoclonal antibody against CD31 (Daco Co), followed by image analysis to count new vessel numbers and statistical analysis was performed. RESULTS: There was significantly more angiogenesis in the PRP group compared to the control group during the first two weeks of the healing process, i.e., inflammatory and proliferative phase (p <> Lyras et al.