Recurrent Interosseous Artery: Anatomy, Course, Function, Imaging

Topic

Recurrent interosseous artery

The recurrent interosseous artery (RIA) is a small but vital branch of the posterior interosseous artery, which itself arises from the common interosseous artery—a short branch of the ulnar artery. It ascends toward the lateral aspect of the elbow, supplying the posterior compartment of the forearm and participating in the arterial anastomosis around the elbow joint.

The RIA primarily supplies the anconeus muscle, lateral aspect of the elbow joint, and proximal extensor muscles of the posterior forearm. Though small in caliber, it plays a critical role in collateral circulation during brachial or radial artery occlusion.

Synonyms

Interosseous recurrent branch
Superior interosseous collateral artery (variant term)
Posterior recurrent interosseous artery

Origin, Course, and Termination

Origin: Arises from the posterior interosseous artery soon after it branches from the common interosseous artery in the upper part of the forearm.
Course:
- Ascends proximally and laterally, passing between the supinator and anconeus muscles.
- Travels posterior to the lateral epicondyle of the humerus.
- Lies deep to the extensor carpi ulnaris and extensor digitorum proximally.
Termination:
- Ends by anastomosing with the middle collateral branch of the profunda brachii artery and the posterior ulnar recurrent artery, contributing to the posterior elbow arterial network.

Relations

Anteriorly: Posterior interosseous membrane and proximal radius
Posteriorly: Anconeus and extensor muscles of the forearm
Laterally: Lateral epicondyle and radial collateral vessels
Medially: Posterior interosseous artery and ulna
Superiorly: Joins the middle collateral artery near the olecranon fossa

Branches

Muscular branches: To anconeus, supinator, and extensor carpi ulnaris
Articular branches: To posterior and lateral aspects of the elbow capsule
Anastomotic branches: Join middle collateral artery and posterior ulnar recurrent artery

Function

Collateral circulation: Provides a posterior collateral route between ulnar and radial systems, ensuring blood flow to the elbow during flexion or arterial obstruction.
Muscular supply: Nourishes proximal extensor muscles and anconeus.
Joint perfusion: Contributes to the posterior elbow arterial network, supporting the capsule and periarticular tissues.

Clinical Significance

Collateral importance: Crucial in maintaining elbow perfusion when brachial or radial arteries are compressed or ligated.
Traumatic injury: May be disrupted in posterior elbow dislocations, fractures, or lacerations.
Iatrogenic significance: Must be preserved during posterior surgical approaches to the elbow and forearm flap harvests.
Vascular pathology: Rarely, thrombosis, stenosis, or aneurysm formation may occur following trauma or inflammation.
Imaging relevance: Important landmark on MRA/CTA in evaluation of elbow collateral circulation and arterial integrity after trauma.

MRI Appearance

T1-weighted images:
- Artery: low-signal (dark flow void) from fast-flowing blood.
- Surrounding fat: bright, clearly delineating the artery’s course.
- Thrombosed or slow-flow segments: intermediate signal within lumen.
T2-weighted images:
- Flowing blood: dark flow void.
- Vessel wall thickening or thrombosis: intermediate-to-bright signal.
- Perivascular edema: mild bright hyperintensity.
STIR:
- Normal artery: dark flow void.
- Inflammation or perivascular edema: bright hyperintense halo.
Proton Density Fat-Saturated (PD FS):
- Normal: dark linear flow void.
- Vasculitis or thrombosis: increased signal or perivascular enhancement.
T1 Fat-Sat Post-Contrast:
- Normal: brisk, homogeneous enhancement of the lumen.
- Occlusion: absence of enhancement distal to thrombus.
- Vasculitic or inflammatory changes: smooth wall enhancement and perivascular enhancement.

MRA (Magnetic Resonance Angiography) Appearance

Normal:
- The recurrent interosseous artery appears as a small, enhancing vessel ascending obliquely behind the lateral epicondyle.
- Best visualized on 3D TOF or contrast-enhanced MRA sequences.
Pathology:
- Occlusion or stenosis: segmental signal loss or reduced caliber.
- Aneurysm: focal saccular or fusiform contrast-filled dilation.
- Collateral circulation: small serpiginous vessels around the olecranon and lateral elbow indicate compensatory flow.

CT Appearance

Non-Contrast CT:

Vessel lumen poorly visualized unless calcified.
Chronic calcific changes may appear as curvilinear hyperdense lines along the posterior forearm.
Useful for assessing bony relations and detecting trauma-induced vascular displacement.

Post-Contrast CT (standard):

Artery seen as a small enhancing tubular structure posterior to the lateral epicondyle.
Clearly distinguishable from adjacent veins on arterial phase imaging.
Pathology such as wall thickening, hematoma, or pseudoaneurysm is readily identifiable.

CTA (CT Angiography) Appearance

Normal:
- The recurrent interosseous artery is visualized as a fine, contrast-filled branch arising from the posterior interosseous artery, coursing upward to join the middle collateral artery.
- Best appreciated in arterial-phase CTA with thin-slice reconstructions and MIP (maximum intensity projection) techniques.
Pathology:
- Occlusion: abrupt cutoff or segmental non-opacification.
- Aneurysm: localized focal dilation with well-defined contrast filling.
- Collateral network: serpentine enhancing vessels around the posterior elbow in chronic obstruction.
- Traumatic pseudoaneurysm: irregular contrast outpouching adjacent to arterial course.