These twin sisters are undergoing leg lengthening treatment. Their mother turns bolts on the external fixators of the leg to increase the distance between the two parts of the the surgically broken bone 1 millimeter a day. (Custom Medical Stock Photo. Reproduced by permission.)

To lengthen a leg surgically, an incision is made in the leg to access the femur (A). A surgical drill is used to weaken the femur so the surgeon can break it. During the operation, screws are drilled into the bone on both sides of the break, and an external fixator is applied (B). The gap between the two pieces of bone is increased gradually (C), so new bone growth results in a longer leg (D). (Illustration by GGS Inc.)