They came, they were going to be the second coming, Lange gave no support, they went away.
The system had some merit for some one needing that extra protection. I know one prominent orthopod who is a good strong skier who used them. He said he could set them up to not release when they shouldn't and they were seemed good that way. I'm not sure he ever even got to the position where he needed them to release to avoid injury.
No one bought them though which isn't surprising since Lange didn't even include them in their catalogue the first year and gave no promotional or awareness support at all at least here in Canada.