Clean Run Magazine - June 2010 - 58

Platelet-rich Plasma:

Is It the Future of Ligament and Tendon Injury Care?

By Peter J. Lotsikas, DVM, DACVS and Jennifer A. Brown, DVM, DACVS

The use of regenerative medicine has become increasingly popular in both human and veterinary medicine for a variety of disease processes. The goal of regenerative therapies is to stimulate damaged tissues to heal, or regenerate, to their normal functioning state. Stem cells are the most common form of regenerative medicine studied and used in clinical practice. However, other types of regenerative medicine, such as tissue engineering and utilizing biologically active molecules to stimulate regeneration, are also being used and studied. Platelet rich plasma (PRP) is a regenerative medicine therapy that is thought to hasten healing of tissues when applied directly to the site of injury. PRP was first used in 1987 by Ferrari et al. to seal an incision during open heart surgery in hopes of reducing the need for an excessive transfusion volume. Since its original debut, a plethora of case studies have been published within the human literature documenting the safe use of PRP in oral surgery, periodontal surgery, neurosurgery, ophthalmology, wound healing, bone healing, joint replacements, and more recently, sports injuries. The use of PRP for athletic injuries is an area of intense research and clinical application. However, its clinical use has outpaced scientific studies and large scale clinical trials qualifying the advantageous use of PRP.

What is Platelet-rich Plasma and How Does It Work?
Platelets are the smallest cell type found in blood and are largely known for their role in hemostasis (clotting of blood) and wound healing. Platelets circulate in the body in an inactive state and have an average life span of 7-10 days. They require a stimulus, like injury to a blood vessel, to trigger them into action. Once activated, platelets become sticky, which allows them to adhere to a damaged region of a blood vessel and to one another. This results in the formation of a “patch” or clot over the traumatized area of the blood vessel. Platelets also contain two types of granules: one that contains serotonin, thromboxane, histamine, dopamine, calcium, and adenosine, and one that carries bioactive growth factors. The first granule type increases vascular permeability, which allows access of inflammatory cells to the site of damage and contributes to the clot formation.
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The second type of granule releases the growth factors, stimulating other cells in the body to migrate to the area of trauma, thus facilitating tissue healing. Various growth factors identified within the platelet have been named, and all have acronyms by which they are referred to. The two factors that are thought to have

the most influential role in wound healing are transforming growth factor-beta (TGF-β) and platelet-derived growth factor (PDGF). It is the growth factors contained within the platelets that are of significance for use in tissue injuries. In dogs, the normal platelet concentration is 200,000-500,000 platelets per microliter (µL or 0.000001 liter). To obtain platelet-rich plasma, the patient’s blood is mixed with an anticoagulant and processed either manually by spinning it in a centrifuge to separate its components (centrifugation) or through an automated system. This processed fraction of the blood is termed “platelet-rich plasma.” With both the automated and manual processes the goal is to achieve the highest concentrations of platelets and remove the other components of the blood such as the red and white blood cells.
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Clean Run Magazine - June 2010

Table of Contents for the Digital Edition of Clean Run Magazine - June 2010