What Can You Tell Me @ Prolotherapy (knee Stem Cell

what can you tell me @ prolotherapy (knee stem cell injections w patient's own stem cells). I do get the synovia-synthetic sp? (chicken rooster comb) injections, which seems to be somewhat evidence based (insurance pays) but cannot seem to find much on the stem cell prolotherapy. Is this (expensive) treatment essentially in physicians' office who practice the alternative medicine/bio-identical medical shops of today?