Neovascularization in Meniscus and Tendon Pathology as a Potential Mechanism in Regenerative Therapies: Special Reference to Platelet-Rich Plasma Treatment

Neovascularization is a complex, multistep process that includes the activation of endothelial cells, degradation of the basement membrane surrounding the blood vessel, formation of tip cells, the sprouting, migration and proliferation of endothelial cells into the interstitial space, and then the generation of space in the matrix to allow for the formation of a new, proper lumen of a newly formed blood vessel. Abundant neovascularization can be found in tendinous tissue obtained from asymptomatic athletes or the meniscus early after the injury. The concept of neovascularization in musculoskeletal system disorders seems to be mainly associated with pain and poor clinical outcomes. On the one hand, this phenomenon allows for tissue regeneration, but on the other, it is present during the degeneration process in connective tissue. Establishing the current concept on neovascularization is also needed. A narrative review of the current literature was conducted using databases including Embase, PubMed and Cochrane. This review aims to investigate the exact role of the neovascularization process in tendon and meniscus lesions and its role as a potential target in clinics, specifically in platelet-rich plasma (PRP) therapy. The stabilization of the neovessels required to achieve the healed tissue, together with the standardization of the PRP injections, can offer an alternative future therapeutic approach for the treatment of tendinopathy and meniscal injuries.