I dislocated my knee in May 2012, tearing my ACL, PCL, LCL, Postereolateral corner, Tibial Plateau fracture and torn meniscus (along artery and nerve damage). I had all the stuff repaired in July and PRP helped me greatly through the rehab process.
There were some trouble spots that were holding me back from more aggressive rehab and activities, but within a few days of the PRP they were gone. I've had PRP done twice, in multiple spots on my knee and it fixed all the problem spots 100%. I have nothing but good things to say about its results, although it can be uncomfortable at the time.