Use of platelet-rich plasma to enhance tendon function and cellularity

Am J Orthop (Belle Mead NJ). 2013 May;42(5):209-14.


Clinical studies have shown inconsistent healing with subjective improvement after use of platelet-rich plasma (PRP) for tendinosis and partial tendon tears. We conducted a study to assess changes after injecting PRP into an intact rabbit patellar tendon (PT) model. In the study group (n = 10), an incision was made over the PT and PRP was injected into multiple sites on the PT. The control group (n = 8) was injected with saline. PTs were harvested 7 and 28 days after injection. Hematoxylin-eosin staining showed hypercellularity in the PRP group at 7 days, but the effect was not as marked at 28 days. At 7 days, polarized microscopy showed increased crimp density of collagen in the PRP group, compared with the control group, demonstrating up-regulation in collagen matrix. Cellular proliferation measured by tritiated thymidine was also significantly increased (P = .02) in the PRP group, compared with the control group, but the difference was not as significant at 28 days. At 7 and 28 days, there were no significant changes in basic fibroblast growth factor, insulin-like growth factor, vascular endothelial growth factor, or platelet-derived growth factor with 2B chains. Injection of PRP into rabbit PT enhances collagen remodeling and hypercellularity with increased metabolic activity, which could have a positive effect on healing.

MeSH terms

  • Animals
  • Cell Proliferation
  • Collagen / metabolism
  • Fibroblast Growth Factor 2 / metabolism
  • Insulin-Like Growth Factor I / metabolism
  • Patellar Ligament / metabolism
  • Patellar Ligament / physiopathology
  • Platelet-Derived Growth Factor / metabolism
  • Platelet-Rich Plasma*
  • Rabbits
  • Tendon Injuries / metabolism
  • Tendon Injuries / physiopathology
  • Tendon Injuries / therapy*
  • Vascular Endothelial Growth Factor A / metabolism
  • Wound Healing / physiology*


  • Platelet-Derived Growth Factor
  • Vascular Endothelial Growth Factor A
  • Fibroblast Growth Factor 2
  • Insulin-Like Growth Factor I
  • Collagen