Platelet-rich Plasma (PRP)
Platelets are a component of normal blood. Their main role is to stop bleeding when a blood vessel gets damaged. When there is a breach in a blood vessel (e.g. if we cut ourselves) the platelets circulating in the blood come into to contact with collagen outside of the blood vessels. This causes them to stick together, plug the defect and stop the bleeding. Once this occurs the platelets then become “activated” and they send off signalling molecules to other cells that are involved in the repair process. This stimulates surrounding cells to start replicating and laying down new tissue to repair the vessel and the surrounding tissue.
PRP is produced by taking a sample of whole blood from the patient, processing it to remove the unwanted blood components, then concentrating the platelets by 6 to 9 times. The healing properties of the platelets are then exploited by injecting the PRP into an area of poor blood supply like a joint or tendon, or into an area where an increased concentration of platelets will assist in accelerating and improving the quality of healing such as a chronic recurrent muscle tear.
The use of PRP began in the 1980s to when dentists and maxillofacial surgeons started using it to increase the success of bone grafting to the jaw. Over the decades its use expanded to include orthopaedics. It has become a more mainstream treatment over the last 10 to 15 years as the body of high-level evidence grows on the safety of the treatment and the improved pain and functioning over an extended period.
It must be remembered that PRP is not a medicine made in a laboratory, it is a product that is produced from your own body. It is this property that makes the use of PRP an extremely safe treatment, but also makes it variable between individual patients. Evidence and experience suggests that about 90% of patients will have a positive response to PRP treatment. PRP treatment in osteoarthritis will not permanently replace the lost cartilage in your joint. At present there is no treatment available that will categorically do this. What it can do is alter the cellular microenvironment to restore the balance back towards a reparative state, reduce the products of inflammation that stimulate pain and slow down disease progression.