The fusiform-shaped belly of the fibularis brevis muscle is situated deep to the larger fibularis longus muscle (Standring).
Routine dissection and study of a 74-year old Caucasian female cadaver by medical and physical therapy students in our Department revealed an anomaly in the insertion of the fibularis brevis muscle of the right leg.
Dissection demonstrated, in agreement with the usual description in the literature, that the belly of the fibularis brevis muscle originated on the lateral surface of the lower two-thirds of the fibula and its long flat tendon of insertion attached to the base of fifth metatarsal.
Fibularis brevis muscle has a variety of anomalous insertions.
It usually arises from fibularis brevis muscle, and/or a variety of other structures including fibularis longus, fibularis tertius or the fibula.
Its miniature belly usually arises from the fibula or belly of fibularis brevis muscle, and gives rise to a tendon which passes behind the ankle before inserting upon the dorsal surface of the fifth metatarsal.
The fibularis brevis muscle was first classified as Type II then reclassified as Type IV (Mathes & Nahai; Yang, et al, 2005).
The distally pedicle fibularis brevis muscle flap is proved to be more helpful to cover these defects and can reach areas distal to the lateral malleolus (Eyssel & Dresing, 1989; Eren et al, 2001; Koski et al, 2005; Yang et al.).
Fibularis longus muscle was dissected to identify the arterial pedicles that supply the fibularis brevis muscle, and then it was removed to expose the whole length of the fibularis brevis muscle.
The upper portion of the medial part of fibularis brevis muscle got arterial pedicles from the anterior tibial artery.
The distally based fibularis brevis muscle flap is a reliable alternative for covering defects in the ankle region.