Everyone is talking about PRP injections for joint and soft tissue problems. It is one of a number of the regenerative medicine injections used in joints, tendons and muscle to improve healing and reduce pain.
I try to sift through the fog to present up-to-date evidence for PRP injections.
First, what is PRP?
PRP is short hand for platelet rich plasma. It's a process where blood is taken from a patient (via simple venesection) and spun down so the layers of blood -red cells, white cells and plasma - are separated. The plasma contains a higher concentration of platelets, which contain growth factors. This serum is separated from the other layers and injected into a joint or soft tissue.
How does an injection of PRP reduce pain?
We don't know the answer yet, but there are many studies analysing the effects of PRP on cells and tissue in the lab.
Is there evidence for PRP ?
Yes there is limited evidence for PRP injections for the following conditions:
- 1)Knee osteoarthritis: There are now over 15 high level studies called randomised controlled trials that show PRP is better than other substances for improving pain and loss of function with knee osteoarthritis.
- 2) There is some limited higher-level evidence that PRP is better than cortisone for tennis elbow
- 3) There is one high level study that shows that PRP is more effective than cortisone in managing pelvic tendinopathy, hip tendinopathy or trochanteric bursitis
- 4) There is some lower level evidence to suggest that PRP helps with heel spurs, plantar fasciitis and rotator cuff or shoulder tendon problems but the evidence is less strong.
There is no evidence PRP is effective for other joints and tendons. I suggest avoiding PRP injections for Achilles and patellar tendons.
So in summary, yes for knee osteoarthritis and perhaps for arthritis in other joints such as ankle, shoulder or hip. Maybe for tennis elbow and hip tendon pathology and sometimes for heel spurs or plantar fasciopathy. However, these injections should only be performed in conjunction with a comprehensive rehab programme.
Of note, NICE (the organisation that advises on effectiveness of interventions in the UK) have just released advise giving the green light to PRP injections.