Plasma is the liquid portion of whole blood. It is composed largely of water and proteins, and it provides a medium for red blood cells, white blood cells and platelets to circulate through the body. Platelets, also called thrombocytes, are blood cells that cause blood clots and other necessary growth healing functions.

Platelet activation plays a key role in the body's natural healing process.

Platelet-rich plasma (PRP) therapy uses injections of a concentration of a patient’s own platelets to accelerate the healing of injured tendons, ligaments, muscles and joints. In this way, PRP injections use each individual patient's own healing system to improve musculoskeletal problems.

PRP injections are prepared by taking anywhere from one to a few tubes of your own blood and running it through a centrifuge to concentrate the platelets. These activated platelets are then injected directly into your injured or diseased body tissue. This releases growth factors that stimulate and increase the number of reparative cells your body produces.

Ultrasound imaging is sometimes used to guide the injection. The photographs below illustrate a PRP injection into a patient's torn tendon. The ultrasound guidance is shown at left and the injection is shown at right.