LAUSR

BACKGROUND The large number of transposition flap geometries available for cutaneous reconstruction often makes the design of these flaps difficult for less experienced dermatologic surgeons. OBJECTIVE To present a conceptual approach to designing transposition flaps based on 2 elementary angles. MATERIALS AND METHODS First, a simplified framework for designing transposition flaps is presented, based on: (1) the takeoff point of the flap, (2) the angle between the primary limb and the primary defect (Angle A), and (3) the angle between the secondary limb and the primary limb (Angle B). Next, a comprehensive literature review highlights applications of the above conceptual approach in the design of z-plasties and single-lobed and multi-lobed transposition flaps. RESULTS Different types of transposition flaps all share the same key design elements, and modifications to Angle A and Angle B predict flap biomechanics. CONCLUSION The design of transposition flaps can be simplified by understanding how 2 elementary angles influence the geometry and biomechanics of various transposition flaps.