A rotation flap is a semicircular skin flap that is rotated into the defect on a fulcrum point. The flap must be adequately large, and a large base is necessary if a back-cut will be needed to lengthen the flap. If the flap is too small, the residual defect can be covered by mobilizing the surrounding tissue.
A drawback of rotation flaps is the extended cutting and undermining needed to create the flap, thus increasing the risk of hemorrhage and nerve damage.
References
Weerda, Hilko (2001). Reconstructive Facial Plastic Surgery: A Problem-Solving Manual. Thieme Medical Publishers. ISBN 1588900762.