Evaluation of the Effect of Platelet Rich Plasma (PRP) in Tendon Gap Healing by Measuring Collagen Synthesis in Guinea Pig

Objectives- Hydroxyproline is a specific amino acid of collagen which is widely used to estimate the collagen content in biological specimens. The purpose of this study was to compare the effect of the Platelet Rich Plasma (PRP) on tendon gap healing using two different scaffold made from subcutaneous fascia and polypropylene tube. Design- Experimental study Animals - 16 young adult Guinea pigs Procedures- The animals were anesthetized and 3 cm incision was made on the caudal surface of the right rear limb. The deep digital flexure (DDF) tendon was severed to induce a 0.7 cm long gap. The animals were divided into 4 groups. Group 1: A tube scaffold was made from the subcutaneous fascia of the back of animal, and the two ends of severed tendon were sutured into the tube scaffold. No PPR was injected. Group 2: Similar to the first group but PRP was injected into the scaffold. Group 3: a 2.0 cm long polypropylene tube was used as scaffold and the two ends of severed tendon were sutured into this tube. No PRP was injected. Group 4: Similar to the third group but PRP was injected into this tube scaffold. After 6 weeks the animals were euthanized and tendon samples were prepared for measurement of hydroxyproline content. Results- The group 2 and 4 that received PRP, showed significant statistical difference in both Hydroxyproline and collagen content compared to their control groups 1 and 3 respectively (P<0.05). The polypropylene scaffold (group 3) was significantly better on tendon gap healing, compared to subcutaneous fascia scaffold (group 1) (P<0.05). The group 4 had a better effect on tendon gap healing significantly (P<0.05) compared to the group 2. Conclusion and Clinical Relevance - PRP in two different scaffolds improved the healing significantly compared to the groups without PRP, due to the effect of growth factor rich granules of the platelets. In group 4 synergistic effects of both PRP and polypropylene tube scaffold was observed. So the PRP was effective to enhance the healing process of tendon gap in Guinea pigs.