Platelet Rich Plasma (PRP) Injection is used in the treatment oftendinopathy (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 patientsown venous blood from the opposite arm. This blood is spun in a machine called a centrifuge to separate the redblood 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 theinjection.
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 notrecommended 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 slightlystiff for a few weeks after the injection. It takes several weeks for the symptoms to start to improvebut 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 weekbefore and two weeks after the injection.
Most surgeons will recommend a course of physiotherapy afterthe injection to encourage healing and restoration of normal function.
How does PRP work?
Platelets provide many of factors responsible for healing oftissues
(TGF-B, bFGF, PDGF, EGF, VEGF and CTGF). The platelets are activated at the siteof injection by a technique called peppering in which several passes of theneedle are performed.
PRP injection causes an inflammatory response that leads tohealing of the degenerate tendon. This means that pain is normal after the injection and may be associatedwith 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 twoweeks after the injection as this will alter the therapeutic inflammatoryresponse if the injection.
Is there evidence that PRP injection works?
There is evidence from randomised control trials that PRP iseffective in relieving pain associated with tendinopathy. One study by Mishra and Pavelko compared PRP injection to injection oflocal anaesthetic in a group of patients with tennis elbow. They reported 60% improvement in painscores in the PRP group at 8 weeks compared to 16% in the local anaestheticgroup.
A further study by Peerbooms et al compared PRP injectionwith injection of corticosteroid. In this study initial improvement in pain scores and DASH functionscores in the steroid group were not maintained beyond two months of the injection but the PRPgroup 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 whereno 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)