Platelet rich plasma (autologous serum) injections

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My thoughts on PRP/serum injections:

When looking at treatments for anything, I like to split into:
(1) BENEFITS of treatment (proven or suspected)
(2) RISKS/side effects of treatment (proven or suspected)
(3) COST of treatment, incl. value for money taking (1) and (2) into account.

The best thing you can say about PRP, if you ignore the grey area of WADA in an elite athlete, is that RISKS are extremely low, being an autologous substance. Not zero, as you can physically damage something with a needle, introduce infection, and get an allergic reaction to a platelet activator, but these are all fairly low.

When discussing BENEFITS of PRP to patients, I say that this could help in either of 3 ways:
(1) Chemical effect of growth factors - least plausible IMO, but possible.
(2) Physical effect of prolotherapy/stimulation - very plausible.
(3) Placebo effect - most plausible!

We use one of the cheap setups with our own centrifuge, so cost of a PRP injection at our centre is low. Therefore when you add up potential benefits (with some low grade support), very low risks and low cost, it is an attractive treatment option. Interestingly, the PRP kits which are very expensive seem to arise from the USA, whose health system is remarkable in that the cost of treatment is divorced from the body paying, so expense is less of an issue.

I think the weight of evidence suggests that prolotherapy (i.e. injecting anything) probably assists soft tissue healing, so long as it doesn't chemically inhibit it (?cortisone). If this is accepted, the safest injections are the default best ones to use.

The next questions are: (1) Is anything available CHEMICALLY better than default (saline/glucose) prolotherapy? (2) Does this improvement in outcome, if any, come at a cost? (e.g. aprotinin - collagenase inhibitor, which may be chemically better, but at a cost of higher risk of allergic reaction) (3) Does injection technique matter? Very important question not yet examined by the literature - it is better to deliberately stab at the tendinopathic lesion, for example, or is it better to just bathe the area around the tendon in a minimally invasive fashion and with a shorter injection time? And if it is a prolotherapy effect, do you need multiple injections to make a difference?

[injuryupdate]

Link to NY Times article on PRP

http://www.nytimes.com/2009/02/17/sp...tsburgh&st=cse