Platelet-Rich Plasma (PRP)

WHAT IS PLATELET-RICH PLASMA?

Platelet-Rich Plasma (PRP) is an autologous biological material, meaning it is obtained from the patient's own blood. A sample is taken by venous puncture and then centrifuged to separate its different components: white cells, red cells, platelets and plasma. One fraction of the centrifuged sample contains platelet-rich plasma (PRP). Platelets carry a large number of substances called “growth factors”, which promote cell migration and division. These factors have the potential to stimulate the reparative response of damaged tissues. In recent years, the potential benefit of PRP has been recognised in the treatment of chronic and acute injuries of the musculoskeletal system — tendons, ligaments and muscles — because the normal repair mechanisms of certain structures have a greater tendency to fail or remain incomplete. This “failure” is due to anatomical peculiarities of certain structures, such as poorly vascularised areas of tendons, weight-bearing cartilage, sites of tendon friction, changes of plane or individual anomalies that make certain structures much more prone to chronic injury. It is in these injuries that PRP injections can be most useful to support healing, shorten recovery times and reduce pain. To do this, we deliver to the injured area a much higher concentration of platelet growth factors than usual, obtained from autologous blood. The PRP preparation process begins by drawing 20–40 cc of the patient's peripheral blood, which contains the platelets along with many other components that are not useful for treating these injuries.

INDICATIONS FOR PRP

These are some of the main indications:

• Patellar chondromalacia and moderate knee osteoarthritis
• Patellar tendinosis
• Epicondylosis or tennis elbow
• Achilles tendinosis
• Plantar fasciitis
• Supraspinatus tendinopathy

HOW PRP IS PERFORMED

The procedure is carried out on an outpatient basis, with no hospital admission required, and takes around 45 minutes in total. It starts with the nursing staff drawing the patient's blood and ends with the PRP being injected into the damaged tendon or joint. The blood remains at all times within a closed system, without contact with air or other components.

After centrifuging the blood for 8–10 minutes, it separates into bands containing its different cell types. The platelets remain suspended in the plasma right next to a thin line containing the white cells, which separates the red cells (red fraction) from the plasma (in yellow). The plasma obtained is the platelet-enriched plasma (PRP), containing a platelet concentration 5–6 times higher than blood, together with molecules that help regulate inflammation (cytokines). This highly concentrated platelet fraction is what is known as PRP; when needed, we can also obtain a lower-concentration plasma, which we usually use for peri-tendinous areas, areas of adhesions and neovascularisation around the tendons.

The last step before use is what we call PRP activation, which consists of mixing the plasma with an agent that triggers its coagulation. Different products can be used for this, the most common being a calcium salt, which causes the release of the growth factors contained in the alpha granules and a platelet aggregation that increases the viscosity of the plasma so it remains in the tendon or cartilage lesion being treated.

The injection is performed within the following half hour. It is carried out in a sterile setting, and in the case of tendons a prior ultrasound study is performed to locate the lesion to be treated. Once the lesion has been located and the entry plane chosen, the plasma is injected and spread through the lesion, always slowly and steadily to avoid causing the patient pain.

RISKS AND CONTRAINDICATIONS

Because PRP is autologous, the risk of immune reactions or transmission of infectious or contagious diseases is minimal. Reactions reported with the use of PRP are extremely rare. The main risks include local infection (<1%) and pain at the injection site.

PRP is contraindicated for people with skin cancer or clotting disorders.

WHY CHOOSE PRP AS A TREATMENT

It is a natural treatment, as the product is drawn from the patient's own body. Growth factors are particularly indicated for the treatment of tendon conditions, osteoarthritic joints and other injuries of the musculoskeletal system — ligaments, joints and muscles — whether acute or chronic.