Platelet-rich plasma for muscle injuries: game over or time out?

Muscle injuries are common and may be associated with impaired functional capacity, especially among athletes. The results of healing with conventional therapy including rest, ice, compression, and elevation (RICE) are often inadequate, generating substantial interest in the potential for emerging technologies such as platelet-rich plasma (PRP) to enhance the process of soft-tissue healing and to decrease time to recovery. In vitro studies and animal research have suggested that PRP may have benefits associated with the increased release of cytokines and growth factors resulting from supraphysiological concentrations of platelets that facilitate muscle repair, regeneration, and remodeling. Despite the promise of basic science, there is a paucity of clinical data to support the theoretical benefits of PRP. The only double-blind controlled clinical trial was recently reported and showed no benefit of PRP in the time to resume sports activity among athletes with hamstring muscle injury. This review examines the current evidence and the theoretical framework for PRP and muscle healing. Scientific gaps and technological barriers are discussed that must be addressed if the potential promise of PRP as a therapeutic modality for muscle injury is to be realized.