INTRODUCTION
Flap Design and Movement When linear closure along the resting skin tension lines (RSTL) is inappropriate for a given defect, other repairs may be considered. Rotation flaps can be a versatile and reliable workhorse that provides elegant and reproducible solutions to otherwise challenging defects. Rotation flaps retain their connection to a robust vascular supply, thereby being less susceptible to flap necrosis. Furthermore, rotation flaps more readily conform to curvilinear RSTLs, compared to angulated lines created by advancement or transposition flaps that interrupt visual flow. Finally, lower tension closure is achieved by redistributing tension along an arcuate path. The main disadvantages of rotation flaps are their longer scars and large undermining requirements, thereby risking postoperative nerve injury, hematoma, or anesthesia toxicity.
Prior reviews of rotation flaps have served as excellent background resources.1 This review will focus on the practical design and execution of selected rotation flaps that are widely applicable.
Most rotation flaps combine some degree of rotation and advancement. The relative combination of the two movements can be adapted to the defect. An important concept in rotation and transposition flaps is pivotal restraint. Pivotal restraint describes the resistance of flaps to rotational movements due to their pedicles and results in flap shortening. This flap shortening must be considered when designing flaps, especially when working with inelastic skin, such as the nose or scalp.2 Wide undermining around the pivot point or a back-cut into the pedicle will increase flap movement. However, excessively large undermining or back-cut may compromise flap perfusion.
The ideal angle for most rotation flaps is 90 to 180 degrees, and the ideal arc length is 4 to 8 times the defect's width.2 A smaller angle or a shorter arc reduces the flap’s size and scar length, but increases closure tension. A larger angle or a longer arc distributes tension over a longer arc, resulting in lower tension closures, but also results in a longer scar. However, rotation angles exceeding 180 degrees introduce greater closure tension due to geometric restraints on the flap.1,2
Prior reviews of rotation flaps have served as excellent background resources.1 This review will focus on the practical design and execution of selected rotation flaps that are widely applicable.
Most rotation flaps combine some degree of rotation and advancement. The relative combination of the two movements can be adapted to the defect. An important concept in rotation and transposition flaps is pivotal restraint. Pivotal restraint describes the resistance of flaps to rotational movements due to their pedicles and results in flap shortening. This flap shortening must be considered when designing flaps, especially when working with inelastic skin, such as the nose or scalp.2 Wide undermining around the pivot point or a back-cut into the pedicle will increase flap movement. However, excessively large undermining or back-cut may compromise flap perfusion.
The ideal angle for most rotation flaps is 90 to 180 degrees, and the ideal arc length is 4 to 8 times the defect's width.2 A smaller angle or a shorter arc reduces the flap’s size and scar length, but increases closure tension. A larger angle or a longer arc distributes tension over a longer arc, resulting in lower tension closures, but also results in a longer scar. However, rotation angles exceeding 180 degrees introduce greater closure tension due to geometric restraints on the flap.1,2
