First of, what exactly is PRP? Blood contains red blood cells, white bloods, and a bunch of stuff in a liquid called plasma (proteins, nutrients, salts, other solutes, etc.). Platelets are specialized cell fragments (hey, who knew I'd get to do my day job - biology teacher - here on my blog?) that we think of as mainly responsible for clotting, but they also produce a variety of proteins called growth factors. Growth factors, in the simplest definition, promote cellular growth (a.k.a. healing).
A PRP treatment is an injection of your own platelets (cool, because then obviously there's no risk of rejection or other complications). My surgeon did the treatment, and he started by withdrawing a small volume of blood from me (15 mL), which was then centrifuged down to separate the plasma, concentrating all it's components, from the red and white blood cells. That increases the concentration of platelets in that sample of plasma, which should stimulate a rapid healing response. Then, the plasma was drawn off the separated blood and injected into my knee. Um yeah, that hurt a lot!
|My blood after centrifugation.|
The yellow is the plasma, which is drawn off.
|The plasma with increased platelet concentration.|
That was all injected into my left knee.
A smaller bore needle than I was expecting, but still...
The whole procedure took less than half an hour, and I was out of there, limping a bit and with a sore knee, but otherwise no worse for the wear. My surgeon told me to "take it easy" for a week, so we had to define exactly what that meant. We agreed on no activity for two days, then return to easy spinning and pull-buoy only swim for 72 hours, no running for one week. I can live with that.
My knee was definitely sore when I left. I am assuming it was from both the needle itself, and the injection of fluid into the joint. The injection site was a bit tender, but there was also some pretty pronounced (and expected) inflammation in my knee. I was instructed not to take any anti-inflammatories as that would interfere with the whole process. I didn't sleep very well that night as my knee was throbbing, and the next day it was still sore and I was still limping. By about 48 hours, there really wasn't any soreness left.
I'm now at 5 days post injection, and I have to say that my knee feels great. I haven't done any running yet which will be the real test, but I did a moderately-intense trainer ride yesterday and didn't feel any pain at all in my knee. It's hard to separate the placebo effect from any actual physical effect, as of course I'm really hoping this treatment will work, but I'm trying to be objective. The swelling has disappeared. I'll go for a run on Wednesday (that's my official waiting a whole week), and am anxious to see how my knee feels.
I go back to the surgeon for a follow-up in a month, where he/we will assess the effectiveness. There is some evidence that people who respond positively to a first injection will do even better with a second, so we'll see where we're at. Health care doesn't cover this as it's fairly new, so each injection is $450... not something to do if I'm not getting good results. But way more than worth it if I do. I am optimistic because of how good my knee feels after not even a week. I'll report back after my run on Wednesday.
Let me know if you have any questions about Platelet Rich Plasma treatments, and I'll do my best to answer them!