Fourth Palmar Metacarpal Artery, Anterior View

Description

Shown from the palmar (anterior) aspect, the fourth palmar metacarpal artery runs distally in the fourth intermetacarpal space, deep to the palmar aponeurosis and flexor tendons, toward the metacarpophalangeal region of the ring and little fingers. Proximally, it arises from the deep palmar arch (typically formed mainly by the radial artery with contribution from the deep branch of the ulnar artery) as it curves across the bases of the metacarpals anterior to the interossei. Adjacent osseous landmarks include the hamate and capitate at the level of the carpus, the fourth metacarpal shaft centrally, and the proximal phalanges distally, with accompanying deep palmar veins coursing alongside the arterial trunks. Small perforating branches can be inferred passing dorsally between metacarpals to anastomose with dorsal metacarpal vessels. Small caliber. High consequence. For hand surgery and trauma, this artery matters because it contributes to the deep palmar vascularization that keeps the ulnar digits perfused when the superficial palmar arch is incomplete or compromised. Lacerations across the distal palm, deep infections tracking along the flexor tendon sheaths, and compartment pressure within the intermetacarpal spaces can all threaten this vessel and its perforators, with ischemia most evident at the ring and little fingertips. The anterior perspective also supports planning for palmar approaches in metacarpal fracture fixation and for understanding bleeding sources during release of Dupuytren contracture, where cords can obscure deep vascular structures. Use this plate in gross anatomy and regional upper limb courses to teach the relationship between the deep palmar arch, palmar metacarpal arteries, and the metacarpal skeleton, or in operative hand texts illustrating palmar incisions, flap design, and vascular risk zones. It also fits radiology and vascular teaching when correlating with Doppler assessment of digital perfusion and Allen test variants in ulnar sided ischemic symptoms. Anatomical accuracy verified by SciePro's Medical Advisory Board.