Split Flexor Carpi Ulnaris Transfer: A New Functioning Free Muscle Transfer with Independent Dual Function

A functioning free muscle transfer is a well-established modality for restoring upper limb function in patients with significant functional deficits. Splitting the neuromuscular compartments of the free muscle based on its intramuscular neural anatomy and using each compartment for a different function will allow for restoration of two functions instead of one at the new distant site.

These authors have previously reported on the clinical use of a pedicled split flexor carpi ulnaris muscle (FCU) transfer. They now reported the use of this muscle as a functioning free split muscle transfer to restore independent thumb and finger extension in a patient with total extensor compartment muscle loss in the forearm and a concomitant high radial nerve avulsion injury.

Nine months postoperatively, the patient was able to extend his thumb and fingers independent of each other. This is the first report of a functioning free split muscle transfer demonstrating two independent functions at the recipient site.