Somayeh Monazzah-Harsini - Department of Pathology, School of Veterinary Medicine, Shiraz University, Shiraz, Iran.

Background: Tendinopathy is the degenerative condition of tendons which characterized by loss of collagen, tissue stability, integrity and strength. It is not an inflammatorycondition with inflammatory cells. Tendinopathy is happened because of natural aging, repetitive stress, and injury and vascular, neural and hormonal inputs.Method: In this study, 100 articles about tendon healing from Pubmed and Google scholar were extracted and studied.Result: The injured tendons which heal with scar tissue adversely affect its function. In addition tendons that heal slowly will have poor vascularization. Different studies aresupportive for PRP use in tendinopathy. Some studies have shown improved tenocyte proliferation and collagen and they have good results. Tendon was among the firstinvestigators of the use of PRP on tenocytes in culture. Some studies have examined the effects of PRP on injured tendon and ligament. Collagen synthesis was greatest in plateletpoor plasma. A study found increased collagen expression after treatment with PRP lysed but they saw there were no significant differences between PRP and plasma or whole blood controls. Another study on tendon explants reported a remarkable incr eased breaking strength and stiffness in explants treated with a collagen graft in combination of PRP Conclusion: Preexisting degeneration has been implicated as a risk factor for acute tendon rupture. Several physical modalities have been developed to treat tendinopathy. There is limited and mixed high-level evidence to support the, albeit common, clinical use of these modalities

tendon, healing, repair