title: The biomechanics of advancement and rotation flaps.
abstract: An animal model (using piglets) has been developed to study the mechanical properties of simple advancement and rotation flaps. The effects of different length-width ratios and defect sizes on the tension required to close a rectangular advancement flap are described. Characteristic curves of force vs. advancement distance are presented and mechanisms discussed. The flaps should have a length-width ratio of a least 1:1; the mechanical advantage of lengthening the flap further is directly related to the measured closing tension. The distribution of tension in a standard 180 degrees rotation flap is analyzed. Maximum tension is found between 90 degrees and 135 degrees (opposite the site of defect closure); this is at variance with the vector commonly pictured. The force required to close a defect with rotation flaps of varying length (45 degree to 180 degrees) is measured. There is little mechanical benefit in extending the flap past 90 degrees.
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena; D062109:Dermatologic Surgical Procedures; D004195:Disease Models, Animal; D005069:Evaluation Studies as Topic; D013524:Surgical Flaps; D013552:Swine