A number of RCT studies have shown that platelet-rich plasma (PRP) injections are not more efficient than autologous blood injections to treat a tendinopathy.
Example: Krogh, T., E. M. Bartels, T. Ellingsen, K. Stengaard-Pedersen, R. Buchbinder, U. Fredberg, H. Bliddal, and R. Christensen. "OP0072 Comparative effectiveness of injection therapies in lateral epicondylitis: A systematic review and network meta-analysis of randomized controlled trials." Annals of the Rheumatic Diseases 71, no. Suppl 3 (2013): 77-78. link reports:
What could explain that platelet-rich plasma (PRP) injections are not more efficient than Autologous Blood injections to treat a tendinopathy?
Is that because Autologous Blood injections already maxed out the potential benefit of growth-factors?
I am mostly interested in epicondylitis (epicondylopathy).