Chris Centeno at his Regenexx blog has a really good article on the Orthokine knee treatment that Kobe Bryant traveled to Germany to receive. Because Dr. Centeno has done quite a few Platelet-Rich Plasma (PRP) injections and has a fairly wide patient database to tap, his opinion should not be treated lightly.
In a word, the data in hand does not support the efficacy of the Orthokine treatment. The WOMAC Knee Function Study that was published in the journal Osteoarthritis and Cartilage in 2008 showed that Orthokine was only slightly more effective than placebos.
Thus, it is expensive, and is only a little better than placebo treatments. PRP, on the other hand, is cheaper, you do not have to go to Germany for it, and has a much better chance of working. Therefore, if you want to try one of the two, Centeno strongly argues that you should pick the PRP treatment rather than the Orthokine treatment.
See Centeno’s excellent post here.