A surprising juxtaposition of the seventeenth century with classical times.
What is considered medically necessary for the American insurance standard is whatever gets you from the bed to the toilet. I am not kidding. No other aspect of daily living other than using the bathroom is considered "necessary," which means your basic prosthetic given to most amputees—a stick with a rubber foot as a leg, or a stick with a hook on the end as an arm, has fundamentally not changed since WWII.
Gizmodo has a feature on Cyborg life this week. I can't verify the truth of this statement, but it sure feels true. If the insurance industry had an up-to-date standard for its work, maybe it wouldn't be so hard to get the use of a terrific technology like Bioness approved.