The keystone flap: not an advance, just a stretch.

Background: The keystone flap is being promoted as an advance in oncological surgical reconstruction. Wound closure with this island flap involves two V-Y advancements toward the center and along the long axis of the island, at right angles to the line of maximum tension when the wound is closed. It is implied that the long-axis advancements enable closure by relaxing the entire flap of skin, allowing it to be stretched more easily along the short axis.