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Topic

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Cubital anastomosis

The cubital anastomosis (also called the periarticular arterial anastomosis of the elbow) is a rich arterial network surrounding the elbow joint, formed by branches of the brachial, radial, ulnar, and profunda brachii arteries. This interconnected system provides collateral circulation to maintain perfusion during elbow flexion, compression, trauma, or occlusion of major arteries.

It is clinically significant during vascular injury, surgical ligation, fractures, and embolization procedures. The network lies within the cubital fossa, around the olecranon, and along the medial and lateral epicondyles.

Synonyms

  • Elbow periarticular arterial network

  • Arterial anastomosis around elbow

  • Anastomotic arcade of the elbow

Components of the Cubital Anastomosis

Major contributing arteries:

  • Superior ulnar collateral artery (from brachial)

  • Inferior ulnar collateral artery (from brachial)

  • Radial collateral artery (from profunda brachii)

  • Middle collateral artery (from profunda brachii)

  • Anterior ulnar recurrent artery (from ulnar artery)

  • Posterior ulnar recurrent artery (from ulnar artery)

  • Radial recurrent artery (from radial artery)

  • Interosseous recurrent artery (from posterior interosseous artery)

Functional Pathways

  • Medial pathway: Superior + inferior ulnar collateral with anterior + posterior ulnar recurrent branches

  • Lateral pathway: Radial collateral + middle collateral with radial recurrent and interosseous recurrent branches

  • Olecranon pathway: Network around triceps tendon insertion

  • Cubital fossa pathway: Anastomosis at the level of brachial artery bifurcation

Relations

  • Anteriorly: Biceps tendon, brachial artery, median nerve

  • Posteriorly: Olecranon, triceps tendon

  • Medially: Pronator teres, ulnar nerve (ulnar groove region)

  • Laterally: Brachioradialis, radial nerve branches

  • Deep structures: Joint capsule, collateral ligaments

Function

  • Provides collateral blood flow during elbow flexion when main arteries may be compressed

  • Ensures adequate perfusion during brachial artery occlusion or surgical clamping

  • Supplies elbow joint capsule, ligaments, and adjacent musculature

  • Supports metabolic demands during high mechanical stress on the joint

MRI Appearance

T1-weighted images:

  • Arteries show low-signal flow voids throughout the cubital fossa and elbow region

  • Surrounding fat planes appear bright, outlining the arterial courses

  • Vessel walls are thin low-signal lines

T2-weighted images:

  • Flow void phenomenon persists—arterial lumen remains dark

  • Arterial walls may be slightly more conspicuous against surrounding intermediate-to-bright soft tissues

  • Nearby muscles show intermediate signal

STIR:

  • Fat suppression increases contrast between arteries (dark flow voids) and soft tissues

  • Surrounding soft tissues appear intermediate signal

  • Excellent for identifying the arterial paths and distinguishing them from veins

T1 Fat-Saturated Post-Contrast:

  • Arteries demonstrate bright, homogeneous intraluminal enhancement

  • Enhances visualization of the medial and lateral anastomotic pathways

  • Joint capsule and synovium also enhance mildly

  • Clear depiction of collateral channels around epicondyles

CT Appearance

Non-Contrast CT:

  • Arteries appear as small soft-tissue density tubes

  • Calcified arterial walls (if present) appear hyperdense

  • Excellent visualization of bony landmarks (epicondyles, olecranon, radial head)

  • Surrounding fat allows contrast between vessels and musculature

Post-Contrast CT:

  • Arteries fill with bright contrast, clearly outlining the anterior, posterior, medial, and lateral anastomotic loops

  • Small arterial branches become more conspicuous around the epicondyles

MRI images

Cubital anastomosis