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Triangular Space
Triangular space lies between teres major, teres minor, and triceps long head for scapular vessels.
RegionUpper Limb
SystemMusculoskeletal System
The triangular space is a small anatomical interval in the posterior shoulder region. Unlike the adjacent quadrangular space, it transmits only a vascular structure — the scapular circumflex artery. It serves as a key surgical and anatomical landmark in posterior shoulder dissections.
Boundaries
Border | Structure |
---|---|
Superior | Teres minor muscle |
Inferior | Teres major muscle |
Lateral | Long head of triceps brachii |
Contents
- Scapular circumflex artery (branch of the subscapular artery, from the axillary artery)
Relations
- Medial to the quadrangular space
- Superior to the triangular interval
- Posterior to the scapulothoracic region, lying deep to the deltoid
Function / Significance
- Allows the scapular circumflex artery to pass from the axilla into the scapular region
- Forms part of the collateral circulation around the scapula
Clinical Significance
- Scapular Collateral Circulation: In cases of axillary artery occlusion, the scapular circumflex artery provides an alternative route for blood to reach the distal limb
- Surgical Landmark: Important in posterior surgical approaches and flap dissections (e.g., latissimus dorsi flap)
- Not commonly involved in compressive syndromes like the quadrangular or triangular interval
Comparative Anatomy
The triangular space and its contained vessel are part of the human-specific vascular design that supports highly mobile scapulohumeral function. The scapular anastomosis plays a role in maintaining perfusion despite positional changes or vascular compromise.
Published on May 12, 2025
Last updated on May 12, 2025
Last updated on May 12, 2025