Origin and course?
The posterior interosseous artery originates from the common interosseous artery (a. interossea communis). The common interosseous artery is a short trunk that branches off the ulnar artery (a. ulnaris) near the proximal border of the forearm and quickly divides into the anterior and posterior interosseous arteries.
The a. interossea posterior enters the posterior compartment of the forearm through an opening in the interosseous membrane (membrana interossea) and runs between the extensor muscles. On cross-sections of the forearm, the posterior interosseous artery and vein are identified (a. et v. interossea posterior).
Topography and neurovascular bundle
In the posterior region of the forearm, the neurovascular bundle includes:
- Deep branch of the radial nerve (r. profundus n. radialis).
- Posterior interosseous artery (a. interossea posterior).
- Posterior interosseous nerve (n. interosseus posterior) — a continuation of the deep branch of the radial nerve.
- Accompanying veins.
The pathways by which these structures enter the compartment differ: the vessels emerge from the proximal opening of the interosseous membrane, whereas the nerve enters through the supinator canal (canalis supinatorius), which wraps around the radius.
Syntopy: a. interossea posterior lies medial to the nerve.
Branches and contribution to vascular networks
Along its course, the posterior interosseous artery communicates with the anastomotic networks of the upper limb:
- Recurrent interosseous artery (a. interossea recurrens) — an early branch of the posterior interosseous artery. It courses toward the lateral epicondyle and anastomoses with a. collateralis media.
- Dorsal carpal network (rete carpi dorsale). Distally, the posterior interosseous artery contributes to this network. The dorsal carpal network is also formed by the dorsal carpal branches of the radial and ulnar arteries. Three dorsal metacarpal arteries (aa. metacarpeae dorsales) arise from the network, giving rise to the dorsal digital arteries (aa. digitales dorsales) near the heads of the metacarpal bones. The network communicates with the deep palmar arch via perforating branches.
Blood supply to forearm muscles
The posterior interosseous artery is listed as a source of blood supply for the following muscles:
- Supinator (m. supinator).
- Abductor pollicis longus (m. abductor pollicis longus).
- Extensor pollicis longus (m. extensor pollicis longus).
- Extensor digitorum (m. extensor digitorum).
- Extensor indicis (m. extensor indicis).
- Extensor digiti minimi (m. extensor digiti minimi).
- Extensor carpi radialis brevis (m. extensor carpi radialis brevis).
- Extensor carpi ulnaris (m. extensor carpi ulnaris).
Clinical significance and collateral circulation
In the distal third of the forearm, the anterior interosseous artery (a. interossea anterior) reaches the posterior compartment by passing through the interosseous membrane from anterior to posterior.
The a. interossea anterior is often comparable in caliber to the radial artery (a. radialis) and participates in collateral circulation in cases of injury or ligation of the main forearm arteries, including the posterior interosseous artery.
Class and exam questions
How does the posterior interosseous artery reach the dorsum of the forearm?
It originates from the common interosseous artery and enters the posterior compartment of the forearm through an aperture in the interosseous membrane.
Which nerve runs alongside it, and what is their syntopy?
In the neurovascular bundle of the posterior forearm, it is accompanied by the deep branch of the radial nerve and the posterior interosseous nerve. The artery lies medial to the nerve.
Which vascular networks does the artery contribute to?
Its recurrent interosseous branch connects with the elbow joint region, and distally the posterior interosseous artery contributes to the dorsal carpal network (rete carpi dorsale).
What else to study on this topic
- Common interosseous artery (a. interossea communis)
- Dorsal carpal network (rete carpi dorsale)
- Deep branch of the radial nerve (r. profundus n. radialis)
- Anterior interosseous artery (a. interossea anterior)
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