Since its first clinical efficacy introduction in 1987, Platelet Rich Plasma (PRP) therapy has had its share of support and skepticism as a method to promote tissue repair and regeneration. Through centrifugation, the plasma becomes five to ten times more concentrated with platelets, growth hormones, and plasma proteins such as fibrin and fibronectin.  PRP is typically injected into areas of trauma to stimulate the body stages of wound healing. This type of therapy is widely associated with the treatments of musculoskeletal injuries. Additionally, PRP therapy can be used in cardiovascular treatments such as heart surgery and angiogenesis, as well as dermatology treatments such as acne scars, contour defects, androgenic alopecia, wound ulcers and striae distensae. Different types of growth factors in PRP have been categorized into their subgroups and associating functions depending on characteristics of platelet-derived, vascular-endothelial, insulin-like, transforming, hepatocyte, fibroblast and epidermal; however, PRP mechanisms of actions are not completely understood by the scientific community. In other words, there is not enough evidence to completely support the efficacy and uses of PRP for clinical treatments.

Even in the early introduction of PRP, the serum was utilized in a progressive way through the use of injections directly into the trauma site of a patient.  A study in 1998 called “Platelet Rich Plasma, Growth Factor Enhancement for Bone Grafts”, was intriguing in the amount of efforts taken to observe PRP effects. In this study, a bone graft harvester along  and ElectroMedics 500 gradient density separator is used to extract the platelets from the plasma. One group of the subjects received the cancellous cellular marrow grafts without PRP, while the other group received grafts with PRP added during the bone-milling process and applied topically after replacement of the defect. The bone grafts were allowed to sit and consolidate for 6 months, with panoramic X-ray observation every two months. Looking specifically at the growth factors PDGF and TGF-b (platelet-derived and transforming, respectively), the bone grafts treated with the PRP showed a 338% increase of platelet count. At 2,4 and 6 months respectively, the PRP treated grafts had 2.16, 1.88, and 1.62 times more platelets than the control group, with a p value for each comparison being .001 showing statistical significance. Does this mean that PRP will absolutely enhance growth factors?  Identifying only 2 of the many growth factors is an oversimplification of human physiology. Even though PDGF and TGF-b are not the only ones with properties of angiogenesis, vascularization, mitogenic, and osteogenesis, the insight of this study still illustrates the significant of PRP in recovery.

On the contrary, studies also showing no correlation between PRP and growth factor activation. In a study by Earl G. Freymiller called “Investigation of Platelet-Rich Plasma in Rabbit Cranial Defects: A Pilot Study,” 15 rabbits received 4 equal defects 8 mm in diameter on their cranium.  The sample group was then given grafts of autogenous bone, PRP injection, grafts of autogenous bone with PRP, and no treatment as control. Observation occurred at 1, 2 and 4 month intervals with 5 rabbits per interval. The results show Bone with PRP has higher percentage bone area recovery than Bone group; however, no statistical significant can be observed (p<0.02) radiographically or histomorphometrically.  Does this mean that PRP has no effect on the rat cranium? An important note is the size of this study The sample size and cranium defects were relatively small. Furthermore among the 4 groups, no statistical differences can be observed in bone density at the 4 months interval. This question the precision of measuring technologies and methods. A reasonable conclusion could be PRP does not adversely affect the process of bone recovery or the study is not precise and therefore inconclusive. 

Given some context, these two studies have merit that does not necessarily contradict each others.  Overall, PRP has been shown to be effective in cosmetics and treatment of chronic tendon injuries but lack scientific proofs in treatments of acute ligament, muscle, and fractures injuries.  Though the scientific community has a understanding of PRP components, the lack of understanding in its holistic mechanism of action brings forth doubt in the clinical setting. This controversy remains prevalent because of its clinical and financial constigents.  In the academic community, Healio posted Orthopaedics Today 2018 containing issues of the demands for PRP definition, comprehensive description, healing mechanisms, and functional outcome. To normal society, PRP efficacy recognition is so limited that few to no insurance plans and workers’ compensation would provide even partial reimbursement.  PRP therapy is currently a luxury for the peace of mind, why else would you spend $600 on something that might not work?

Questions to Consider:

Is Platelet Rich Plasma the same as blood doping and to what extent should it be regulated?

If PRP is effective in all form of wound recovery, what proofs are needed before it can be recognized as part of insurance claim?

References:

[1] Alves, Rubina, and Ramon Grimalt. “A Review of Platelet-Rich Plasma: History, Biology, Mechanism of Action, and Classification.” Skin Appendage Disorders, Karger Publishers, 6 July 2017, doi.org/10.1159/000477353.

[2] Arshdeep, Kumaran M S. Platelet-rich plasma in dermatology: Boon or a bane?. Indian J Dermatol Venereol Leprol 2014;80:5-14

[3] Marx, Robert Lee DDS. Platelet- rich Plasma Growth factor enhancement for bone grafts. Oral and Maxillofacial Surgery 1998

[4] Aghaloo, Tara L DDS. Investigation of platelet-rich plasma in rabbit cranial defects: A pilot study. Journal of Oral and Maxillofacial Surgery 2002