The new palmaris brevis musculocutaneous flap.

The palmaris brevis muscle is thin and subcutaneous on the ulnar side of the palm, attached to the medial border of the palmar aponeurosis. It ends in the dermis of the hand's ulnar border. A new musculocutaneous flap composed of the palmaris brevis muscle and its overlying hypothenar skin is presented. The free flap, from the vascular pedicle of the ulnar artery, was made. This flap sacrifices the ulnar artery. It was applied to 3 patients with palmar thumb defects, all of whom were successfully reconstructed.