Posterior Interosseous Artery, Posterior View

Description

Arising from the common interosseous artery off the ulnar artery, the posterior interosseous artery passes posteriorly through the proximal interosseous membrane to enter the extensor compartment, then descends on the posterior aspect of the forearm between the superficial and deep extensor groups. Proximally, the brachial artery divides in the cubital fossa into the radial and ulnar arteries, while the posterior interosseous artery tracks distally toward the dorsum of the wrist, typically accompanied by venae comitantes. Superficial venous channels such as the cephalic and basilic veins remain more anterior and lateral or medial in the upper limb, with the median cubital vein crossing the cubital fossa superficially. Posterior orientation matters because the posterior interosseous artery travels with the posterior interosseous nerve in the same compartmental corridor after the nerve exits the supinator, a relationship that becomes clinically relevant in posterior interosseous nerve syndrome and in approaches to dorsal forearm exposures. Lacerations to the extensor mass, dorsal forearm fasciotomies, and fixation of proximal radius or ulna fractures can all place the vessel at risk, and this course also explains why dorsal compartment swelling may threaten distal perfusion even when the radial pulse remains palpable at the wrist. Small branches feed extensor carpi ulnaris, extensor digitorum, and the deep extensor plane. A practical landmark. Use this artwork in upper limb anatomy modules, surgical anatomy teaching for dorsal forearm approaches, and in orthopedic or hand surgery publications that need a clean posterior map of arterial supply relative to the extensor compartment and superficial venous access points at the elbow. It also supports patient-facing or trainee materials on venipuncture sites by contrasting superficial veins with deeper arterial pathways. Anatomical accuracy verified by SciePro's Medical Advisory Board.