Total FX on Thighs for Tightening?

I was told by my Doctor that he can do the Total FX on my thighs to help with the sagging skin and that the treatment will have a tightening effect. I cannot find anywhere on the Internet where it's used on any area other than the face and am wondering how common this is, and if it is at all effective. I've already had liposuction but that has not helped with the sagging. Any advice would be greatly appreciated!