Distally Based Pedicled Flexor Carpi Ulnaris Muscle Flap: An Anatomical Study and Clinical Application

Background: Proximally based, pedicled flexor carpi ulnaris (FCU) muscle flap has been described previously for soft tissue coverage of the proximal forearm and elbow. No studies have been done on the distal muscular perforators and its use as a distally based flap. Methods: Ten fresh-frozen cadaveric dissections were done. Specimens were injected with latex to facilitate identification of the perforators. Distal muscular perforators were dissected and distances of the pedicles from the distal wrist crease and ulnar styloid were measured and recorded. A clinical case is also presented where a distally based FCU muscle flap was used for coverage in a patient with median nerve neuroma. Results: A distal muscular perforator and a second more proximal perforator were identified in all specimens. The average distance from the most distal muscular perforator to the ulnar styloid was 3.0 cm. The average distance to the wrist crease was 4.6 cm. The more proximal perforators had an average distance to the ulnar styloid and wrist crease of 7.3 cm and 8.8 cm, respectively. At 7 months post-op, the patient who underwent median nerve neurolysis and coverage with pedicled FCU flap had much improved sensation, with complete resolution of pain and tingling, and without any functional deficits. Conclusions: The use of a distally based FCU muscle flap is a good option for soft tissue coverage of the distal forearm, wrist, and hand. The distal muscular perforators from the ulnar artery exhibit a relatively consistent anatomy.