Wounds that are too tight to close in one direction can frequently be repaired by redirecting tension vectors away from the primary motion. Rotation is the simplest method of redirecting tension vectors and reducing wound closure tensions.1 The design of a traditional rotation flap utilizes a curvilinear incision along an arc adjacent to the primary surgical wound. As a rotation flap is executed, the direction of wound closure tension is effectively changed. Rotation flaps partially or completely redistribute and redirect closure tension from a primary defect to a secondary arciform defect.2,3 Laxity of the adjacent tissue allows the flap to be rotated into the primary defect, and the tension vector is reoriented in the direction of the secondary defect or secondary motion of the flap. Rotation flaps also allow for displacement of dog-ears to more favorable locations. Well-designed rotation flaps create scar lines that are hidden along facial boundaries or within relaxed skin tension lines. There are few repairs as elegant and seemingly simplistic as a well-designed and well-executed rotation flap. In practice, flaps that utilize only rotational motion are uncommon, and a simplistically designed rotation flap rarely suitably repairs an operative wound.
Rotation flaps may involve pure rotation or combinations of rotation and advancement. A common clinical misconception is that rotation flaps borrow lax tissue from a curvilinear donor area. While laxity along the sweep of flap rotation is integral to the mechanics of the design, the crucial planning involves anticipation of tension vectors generated from closure of the secondary defect created as the primary defect is closed. The pedicle of a rotation flap and the mobility of the point of pivotal restraint are the key determining factors of the success or failure of a given repair. In any rotation flap, tension vectors may exist in multiple directions and depend on intrinsic tissue properties, orientation, design, and execution. The uniqueness of rotation flap biomechanics is, therefore, a calculated alteration of the direction of major closure tension forces.
Historically, the rotation flap was a workhorse for plastic surgeons who utilized the flap to repair large defects following pilonidal cyst removal and for the repair of finger wounds. In the past several decades, rotation flaps have found a greater use for the reconstruction of facial wounds.
Rotation flaps may be conceptualized as involving a primary defect, a primary tissue movement, a secondary defect, and a concomitant secondary tissue movement (Fig. 3.1). The primary defect is the original wound. The primary tissue movement involves partial or total closure of that wound by redraping of the rotated flap. As the primary defect is closed, usually under minor tension, a secondary defect is created along the curvilinear sweep of the flap. The closure of this novel secondary defect involves a unique secondary tissue movement. The biomechanical foundation of the rotation flap ...