The outer thighs and buttocks need to be sculpted together during liposuction. These two areas relate to each other so closely that the effects of one on the other must be considered in planning the procedure.
Liposuction is a great way to sculpt the legs. Certainly performing liposuction of the outer thigh when done correctly, should have no ill effect on the buttocks. In fact, it may accentuate them nicely.