Platelet-rich plasma in muscle healing.

The muscle healing process is defined as a complex and dynamic process resulting in the restoration of anatomic continuity and function. This process is characterized by a cascade of events triggered by the tissue injury itself. It is widely accepted that growth factors play a central role in the healing processes by modulating the recruitment, duplication, activation, and differentiation of different cell types. This observation is the basis on which the use of platelet-rich plasma in several circumstances is founded; all of them requiring the activation or the modulation of the tissue repair process. There is an extensive documentation of in vitro and in vivo studies demonstrating the safety and efficacy of growth factors in the muscle healing process. Unfortunately, the precise biological efficacy and the lack of long-term side effects have not been clearly demonstrated. With regard to sports medicine, doping-related issues are still a matter of debate, especially regarding the treatment of muscle injuries. The purpose of this review is to examine the role of growth factors during muscle healing processes and to discuss the implications of platelet-rich plasma in its therapeutic applications. Sports medicine issues are also discussed particularly with regard to antidoping regulations.