M01.03.004 The Triangular Space

The triangular space, located in the axilla, is an anatomical passage connecting the axilla with the posterior scapular region. This space is essential for the transit of vascular structures. In this article, we will explore its borders, contents, and clinical correlations while differentiating it from the triangular interval.

Borders of the Triangular Space

The triangular space has three well-defined borders, forming a triangle with the base laterally and the apex medially.

Illustration:
The triangular space’s boundaries are best visualized in anatomical diagrams to understand its orientation and spatial relationships.

Contents of the Triangular Space

The triangular space acts as a passageway for structures traveling between the axilla and posterior scapular region.

Illustration:
The circumflex scapular artery and vein pass through this space, highlighting its vascular importance.

Clinical Correlation

1. Surgical Implications:
   • During axillary surgeries or procedures, the triangular space serves as a landmark to avoid accidental vascular damage.
2. Differential Diagnosis:
   • The triangular space must be distinguished from the triangular interval, located inferiorly. While the triangular space contains vascular structures, the triangular interval primarily transmits nerves (e.g., radial nerve).

Points to Remember

1. The triangular space is bordered by the teres minor (superior), teres major (inferior), and the long head of the triceps brachii (lateral).
2. It contains the circumflex scapular artery and vein.
3. Do not confuse it with the triangular interval, which is located inferiorly.

Bibliography

• Gray’s Anatomy: The anatomical borders and contents of the triangular space.
• Clinical Anatomy by Regions: Emphasizes the distinction between the triangular space and interval.