I get this question a lot and the simple answer is it hasn't been available and around that long in the U.S. As well, the manner in which it was introduced and marketed initially has also had an effect of keeping it under a bushel basket if you will.
I for one believe it is long past time for every practitioner who helps stop pain and accelerate the healing of the human body's soft tissue (muscles, ligaments, tendons, and nerves) to know about it and to incorporate it into their practice.
It is a tool that I have used to repair labral tears...