Specifically what does "flank" mean? Does that mean hips or back or both?

Flanks are what most people refer to as "love handles."  It is the area on the sides of your stomach, right above your hips.  It's the area that provides you with your curves and shape, and therefore is a great place for liposuction.

Flanks refer to neither your hips nor your back, technically. Flanks refers to the area commonly referred to as "love handles", and is the area along the sides of the abdomen. In a vertical dimension, the flank is the area between the bottom of the ribs and the top of the hips. In a horizontal dimension, it is along your side, between the abdomen in front and the back in back. Some patients have excess fullness limited to the flanks. Others have excess fullness circumferentially (all the way around) so that the borders of the flank are less obvious since the fullness there blends into the fullness at the abdomen and back.

My interpretation of the flanks is the area lateral to the end of the tummy tuck incision and ending about two inches or so before the getting to the middle of the back. The vertical margins I choose is the top and bottom of the hip fat pad.Your surgeon might have a different interpretation.Good luck. Dr. ALDO