Clinical Questions Answered: Platelet-Rich Plasma (PRP)


When you support clinicians in all fields of medicine for over 20 years, you start to accumulate a book of questions and answers acquired through research and experience. In this article, we'll be answering your most common clinical questions regarding PRP.


1. What is PRP?

PRP is an autologous biologic derived from whole blood that is preferentially enriched for platelets and placed at a site of local injury to stimulate healing (1). While platelets are the primary component of PRP, preparations may also contain other cellular components such as white blood cells (WBCs) and circulating progenitor cells. These components all play a critical role in the healing process and are provided at highly concentrated levels in PRP.


2. What Type of PRP is best?

Generally speaking, there are only two types of PRP: Leukocyte-Rich (LR-PRP) and Leukocyte-Poor (LP-PRP). LR-PRP is red in colour and includes a concentration of WBC along with platelets, while LP-PRP is just platelets suspended in plasma. Both have been shown to be advantageous in stimulating healing in specific tissue types and injury locales.

Sports Medicine: While this issue is still up for debate, most level 1 research supports LR-PRP for soft tissue injections and LP-PRP for intra-articular joint injections (2). The reason being that LR-PRP appears to stimulate inflammation which facilities healing in soft tissue injuries, however, this same preparation may cause damage to synoviocytes making LP-PRP better suited for joint injections (3). For low-back injections, the presence of WBC in LR-PRP make it well suited for killing common bacteria such as p. acnes (4).

Cosmetic: LP-PRP does not include any hematocrit, which helps reduce pain for patients during the procedure relative to LR-PRP. The clear plasma appearance of LP-PRP appears to also help reduce post-operative bruising and having patients walk out of the treatment room with dried blood on the treatment area. For these reasons, LP-PRP appears to be the preferred preparation.

But beware, not all LR-PRP and LP-PRP preparations are created equall! It is critical the PRP preparation you choose still includes a concentration of platelets (min. >4x above baseline). Many providers will convince you that platelet concentration is not important, however, numerous research articles support the need for a minimum threshold of 4x platelet concentration to achieve significant clinical results (5,6,7). The Harvest PRP system can produce both types of PRP with platelet concentration between 5 - 9x above baseline (2).

3. Can I use local anesthetics with PRP?

Unfortunately, most local anesthetics are toxic to local stem cell populations and platelets, making them poorly suited as accessories to PRP treatment (8). Based on an analysis of the effect of various local anesthetics on platelet function and mesenchymal stem cells, it appears that lidocaine + epinephrine is the superior solution to mitigate the impact while bupivacaine/ marcaine should be avoided at all costs! (8,9)

While all these substances impact platelet function and MSC viability to some degree, PRP procedures are not always well tolerated. When used sparingly as skin-numbing agent (not mixed directly with the PRP!), the impact on clinical results should be negligible and the majority of clinicians will still use these agents to one degree or another. While we're on the subject, high-dose steroids are also very toxic to these cell types and should also be avoided at all costs during a regenerative injection.

4. How many injections of PRP are needed to achieve results?

The number of injections needed will vary depending on patient age, condition, and other factors which is why it is always best to consult with your HCP to determine the best course of treatment for you.

With that said, most treatment plans and applications of PRP in the literature seem to support a 3-injection protocol for achieving significant clinical results (2). These injections may be spaced 2, 4, or 6 weeks apart with little consensus here. For cosmetic applications, 6 to 12 month annual "maintenance" injections following the initial treatment protocol appear to support the best results (10).

5. What is the average price of a PRP injection in my area?

The average cost of a PRP injection will vary depending on your geographic region, locale, type/volume of injectate, among other factors such as the use of medical imaging (i.e. ultrasound or fluoroscope)

For major cities and metropolitan areas in Canada, it appears that a single injection of PRP will command a price tag between $500 - 1000. For rural areas, these figures generally drop to $400-800.

The price point for cosmetic applications leans towards the higher-end of these numbers, as do PRP injections assisted by expensive equipment such as a fluoroscope.

6. Do I need to activate my PRP?

Primarily, PRP activation is desired when there is a need for the PRP to stay in the site of injection/placement. This can be accomplished by “activating” the PRP, which causes de-granulation, the release of growth factors and creation of a gel-like material via clotting mechanisms. The product is then referred to as a “fibrin-clot” or Platelet-Rich Fibrin. There are a few “activators” available to do this, such as CaCL2, Autologous thrombin, and collagen type l. Each has a different effect on clot formation and growth factor release profile (11).

The use case for this “fibrin-clot” is often in cosmetic procedures or oral-maxillofacial surgery for bone and tissue grafting when we need to pack the PRP into a small space without having it diffuse out into the surrounding tissue. For sport medicine injections, there is limited evidence that pre-activation of the PRP to release growth factors is advantageous, as 95% of growth factors are released in the first 1 hour following injection by endogenous factors beneath the skin (5). Furthermore, a "fibrin-clot" makes it nearly impossible to transfer the solution through a cannula into the treatment area. For these reasons, most clinicians injecting PRP for MSK applications are not activating their PRP prior to use.

7. How can I reduce pain for patients during the procedure?

We've covered most of the ways you can reduce patient pain during the procedure above (i.e. LP-PRP, local anesthesia). However, if additional pain reduction is required there are a few more techniques we've seen clinicians use.

Using a small gauge needle can help reduce pain during injection, with some advocating for as small as a 30-gauge needle (9). While this may be smaller than what some clinicians are used to, there should be no problem injecting a PRP solution with a 30-guage needle provided that the PRP preparation includes an anticoagulant (i.e. ACD-A) to minimize clotting & viscosity.

The addition of 10% Calcium Gluconate in a 1:10 ratio to the PRP can help buffer the solution and reduce the "burning" sensation. However, this can activate the platelets and initiate clotting mechanisms, so clinicians should work quickly to inject following mixing.

Lastly, the use of an injection gun such as the Ultim mesotherapy device during cosmetic procedures can help minimize pain by eliminating variability in injection dose & depth that are the natural result of free-hand injections.



Hopefully we have helped answer some common questions you have about PRP. When you work with MDBiologix, you are accessing a depth of information built over 20+ years in the industry and in collaboration with 100's of clinicians in Canada. For more of your clinical questions answered or hear about how we can help you build your regenerative practice, please contact your local representative at MDBiologix.

REFERENCES

  1. Kevy, S, Jacobson, M. and Mandle, B. Defining the Concentration and Composition of Platelet-Rich Plasma (PRP). Presented at the North America Platelet-Rich Plasma Symposium, September 9, 2011, Toronto, ON, Canada.

  2. Le A, Enweze L, DeBraun M, Dragoo J. Current Clinical Recommendations for Use of Platelet-Rich Plasma. Current Reviews in Musculoskeletal Medicine. 2018. 11. 10.1007/s12178-018-9527-7

  3. Tang Y, Yeaman M, Selsted M. Antimicrobial peptides from human platelets. Infect Immun. 2002;70(12):6524-6533.

  4. Braun HJ, Kim HJ, Chu CR, Dragoo JL. The effect of platelet-rich plasma formulations and blood products on human synoviocytes: implications for intra-articular injury and therapy. Am J Sports Med. 2014;42(5):1204–1210. doi:10.1177/0363546514525593

  5. Marx, RE. Platelet-Rich Plasma: Evidence to support its use. J Oral Maxillofac Surg 2004; 62:489-496.

  6. Cole B, Karas V, Hussey K, Pilz K, Fortier L. Hyaluronic Acid Versus Platelet-Rich Plasma: A prospective, double-blind randomized controlled trial comparing clinical outcomes and effects on intra-articular biology for the treatment of knee OA. Am J Sports Medicine. 2017. 45(2):339-346

  7. Gentile P, Garcovich S. Systematic Review—The Potential Implications of Different Platelet-Rich Plasma (PRP) Concentrations in Regenerative Medicine for Tissue Repair. Int J of Mol Sci. 2020. 21:5702.

  8. Dregalla RC, Lyons NF, Reischling PD, Centeno CJ. Amide-type local anesthetics and human mesenchymal stem cells: clinical implications for stem cell therapy. Stem Cells Transl Med. 2014;3(3):365-374. doi:10.5966/sctm.2013-0058.

  9. Bausset O, Magalon J, Giraudo L, et al. Impact of local anaesthetics and needle calibres used for painless PRP injections on platelet functionality. Muscles Ligaments Tendons J. 2014;4(1):18-23. Published 2014 May 8.

  10. Roohaninasab M, Goodarzi A, Ghassemi M, Sadeghzadeh‐Bazargan A, Behrangi E, Najar Nobari N. SYSTEMATIC REVIEW OF PLATELET‐RICH PLASMA (PRP) IN TREATING ALOPECIA: FOCUSING ON EFFICACY, SAFETY AND THERAPEUTIC DURABILITY. Dermatologic Therapy.:e14768. — 3708

  11. Cavallo C, Roffi A, Grigolo B, Mariani E, Pratelli L, Merli G, Kon E, Marcacci M, Filardo G. Platelet-Rich Plasma: The Choice of Activation Method Affects the Release of Bioactive Molecules. Biomed Res Int. 2016;2016:6591717. doi: 10.1155/2016/6591717. Epub 2016 Sep 8. PMID: 27672658; PMCID: PMC5031826.


This blog post provides general information to help the reader better understand regenerative medicine, musculoskeletal health, and any related subjects. The views and opinions expressed in this post are those of the author and may not reflect the views and opinions of MDBiologix. All content provided in this blog, website, or any linked materials, including text, graphics, images, patient profiles, outcomes, and information, are not intended and should not be considered or used as a substitute for medical advice, diagnosis, or treatment. Please always consult with a professional and certified healthcare provider to discuss if any treatment is right for you.