Zone V Flexor Injury in a Congenital Cleft Hand: A Chance Insight into the Forearm

Abstract Congenital cleft hand is a central longitudinal deficiency often associated with preserved function, and surgical intervention is usually limited to correction of associated anomalies. Consequently, detailed descriptions of forearm anatomy in such patients are limited. We report a case of a zone V flexor injury in a patient with bilateral congenital cleft hand who had never undergone prior surgery and was functionally well adapted. Intraoperative exploration revealed variations in the flexor apparatus, including absence of the flexor digitorum profundus to the index finger, predominantly muscular flexor digitorum superficialis, and accessory muscle corresponding to the absent digit. Radiographic evaluation demonstrated carpal coalition and disorganization. These findings provide insight into adaptive tendon morphology and carpal architecture, with implications for surgical management.