Platelet-rich plasma (PRP) injections

Your blood is made up of four major components: red blood cells, white blood cells, plasma, and platelets. Platelets are tiny fragments of cells in the bone marrow called megakaryocytes. The function of platelets is to aid in the clotting of blood and to help wounds heal, while plasma is the liquid component of blood.

PRP injections use only the plasma and platelets from your blood to stimulate healing in a specific site in the body. To harvest PRP, a nurse will draw some of your blood and then put it in a device called a centrifuge to spin it at a high speed to separate the red blood cells from the other major components of your blood. The red blood cells are then removed to leave behind platelet-rich plasma - a highly concentrated mixture of plasma, platelets and white blood cells (which help protect against infection).

Once the PRP has been prepared, this is drawn up into a syringe, ready to be injected into the site of concern, for example, the knee, elbow or shoulder joint. Before the injection is administered, you will be given a small injection of local anaesthetic under the skin near the affected area. When the area is numb, your consultant will inject the PRP into the joint. In some cases, they may use an ultrasound scan to pinpoint the specific area of treatment so that they can guide the needle to more accurately administer the injection. 

The number of injections you’ll need, and their frequency, will depend on your injury or condition but can range from two to six injections. Your consultant will discuss this with you.

At your initial consultation, your consultant will guide you on how to best prepare for the injection. This may include stopping taking painkillers and anti-inflammatories, and fasting.

As PRP injections promote healing, you will not feel an immediate improvement in your condition. However, the area will begin healing much more quickly than it otherwise would have, so you can expect to notice a reduction in pain in just a few days or weeks. 

You may experience some discomfort and bruising after a PRP injection and you may have some numbness for a few hours due to the local anaesthetic. The most common side effects from a PRP injection are discomfort, pain, and/or stiffness at the injection site.

As PRP injections are prepared using your own blood, they are very safe and the treatment carries a low risk of infection and complications. The treatment is also very minimally invasive, so while there is a small risk of infection, bleeding and nerve damage, this is very rare.