Autologous blood or platelet-rich plasma injections
Platelet-rich plasma (PRP) and whole blood injections are proposed for a variety of healing applications. Concerns are considered medium for safety, medium/high for efficacy, and medium for cost-effectiveness.
Status: Review in progress
Primary criteria ranking
- Safety = Medium
- Efficacy = Medium/High
- Cost = Medium
- Draft key questions published: October 13, 2022
- Public comment period: October 13 to 27, 2022
- Final key questions published: November 29, 2022
- Draft report published: TBD
- Public comment period: TBD
- Final report published: TBD
- HTCC public meeting: TBD
Platelet-rich plasma (PRP) and whole blood injections are treatments that have been utilized for a variety of healing applications in sports medicine and orthopedic medicine. Conditions where PRP or whole blood injections are commonly utilized include refractory acute or chronic ligament injuries, muscle strain injuries, cartilage injuries, osteoarthritis, and tendinopathies. In particular, the use of PRP and blood injections in sports medicine have seen a recent increase in public exposure, as many professional athletes have elected to receive these treatments, especially PRP, for sports-related injuries.
The rationale behind PRP and autologous blood injections (ABI) is to increase the concentration of growth-factor rich platelets around the injured area. These growth factors include platelet-derived growth factor (PDGF), insulin-like growth factors (IGF-I and IGF-II), and vascular endothelial growth factor (VEGF). This influx of platelets is thought to promote the healing process by enhancing regeneration and increasing angiogenesis. In particular, PRP preparations contain a concentration of platelets that is at least four-fold higher than that in blood to approximately one million platelets per microliter, a concentration that is thought to be clinically active. These therapies are outpatient procedures and utilize the patient's own blood to obtain the PRP or whole blood used in the injection. PRP is prepared by centrifugation of autologous blood to separate out the platelet-carrying buffy coat layer from platelet-poor plasma, red blood cells and white blood cells; the buffy coat layer and some of the plasma are then isolated and recentrifuged to obtain the PRP to be used in the injection. Platelet-activating factors like thrombin may be added to PRP to stimulate platelets to release growth factors and increase recruitment of tissue repair factors. No such additional processing occurs for whole blood injections after venipuncture. It is common to add local anesthetic to PRP and whole blood samples to reduce pain at the injection site. Injection is usually performed under ultrasound guidance, and can be repeated if needed.
Despite the increased use of PRP and whole blood injections for healing applications, the efficacy and safety for PRP and whole blood injection treatments are not well established. In particular, there are additional issues regarding PRP: while the technology to obtain PRP is FDA-approved, PRP itself is currently not indicated for direct injection. Additionally, the number of PRP-preparation systems and lack of standardization for the platelet concentration of PRP also make establishing true efficacy difficult.