Platelet Rich Plasma (PRP)
Platelet Rich Plasma (PRP) Injection is used in the treatment of tendinopathy (degeneration of tendons). Around the elbow it is most useful in the treatment of tennis elbow(lateral epicondylosis), golfers elbow (medial epicondylosis) and distal bicepstendinopathy.
What does a PRP injection involve?
PRP is obtained by drawing off 30 to 60ml of the patients own venous blood from the opposite arm. This blood is spun in a machine called a centrifuge to separate the red blood cells, PRP and platelet poor plasma. The PRP is then drawn off and buffered using sodiumbicarbonate to make it less acidic so that it is not so painful after the injection.
A small volume of local anaesthetic is injected into thesite where the PRP is to be administered.
1ml of PRP is then injected into the injured tendon using apeppering technique in which several passes of the needle are performed.
The elbow may be sore after the injection and driving is not recommended until the elbow can be used comfortably.
What can I expect after a PRP injection?
The elbow will be a little more painful and may be slightly stiff for a few weeks after the injection. It takes several weeks for the symptoms to start to improve but gradual steady improvement in pain symptoms can be expected. Non-steroidal anti-inflammatory medication(ibuprofen, diclofenac sodium etc.) should not be taken for at least a week before and two weeks after the injection.
Most surgeons will recommend a course of physiotherapy after the injection to encourage healing and restoration of normal function.
How does PRP work?
Platelets provide many of factors responsible for healing of tissues
(TGF-B, bFGF, PDGF, EGF, VEGF and CTGF). The platelets are activated at the site of injection by a technique called peppering in which several passes of the needle are performed.
PRP injection causes an inflammatory response that leads to healing of the degenerate tendon. This means that pain is normal after the injection and may be associated with some mild swelling and stiffness at the elbow. Non-steroidal anti-inflammatory medication (ibuprofen, diclofenac sodium etc.) should not be taken for at least a week before and two weeks after the injection as this will alter the therapeutic inflammatory response if the injection.
Is there evidence that PRP injection works?
There is evidence from randomised control trials that PRP is effective in relieving pain associated with tendinopathy. One study by Mishra and Pavelko compared PRP injection to injection of local anaesthetic in a group of patients with tennis elbow. They reported 60% improvement in pain scores in the PRP group at 8 weeks compared to 16% in the local anaesthetic group.
A further study by Peerbooms et al compared PRP injection with injection of corticosteroid. In this study initial improvement in pain scores and DASH function scores in the steroid group were not maintained beyond two months of the injection but the PRP group had continuing improvement in symptoms up to 12 months. A follow up study has reported ongoing relief of symptoms up to two years after PRP injection.(Gosens 2011) Those treated with corticosteroid where no better at two years than they were before the injection.
A recently published study has found that PRP is more effective in the treatment of tennis elbow than injection whole autologous blood (blood from the patient).(Thanasas 2011)