Use of Platelet-Rich Plasma to Enhance Tendon Function and Cellularity
John G. Lane, MD, Robert M. Healey, BS, MBA, Derek C. Chase, MD, and David Amiel, PhD
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 wereharvested 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.