Quadrangular space
Suprascapular and axillary nerves of right side, seen from behind. Quadrangular space is the lateral space, labeled in green at center right. Axillary nerve is visible entering it.
The scapular and circumflex arteries. (Quadrangular space is visible but not labeled. Posterior humeral circumflex artery is visible entering quadrangular space at center right.)
Gray's	subject #149 589

The quadrangular space (or quadrilateral space) is an axillary space in the arm. This is a clinically important anatomic space in the arm. In the quadrangular space, the axillary nerve and posterior circumflex humeral artery can be compressed or damaged in the space due to space occupying lesions or disruption in the anatomy due to trauma. Symptoms include axillary nerve related weakness of the deltoid muscle in the case of any significant mass lesions in the quadrangular space.

Contents 1 Boundaries 2 Contents 3 Additional images 4 References 5 External links

[edit] Boundaries

It is bounded by:^[1]

• above/superior: the Subscapularis and Teres minor (inferior border). Some sources exclude the Teres minor.^[2]
• below/inferior: the Teres major (superior border)
• medially: the long head of the Triceps brachii
• laterally: the surgical neck of the humerus

[edit] Contents

It transmits the axillary nerve and posterior humeral circumflex artery.

[edit] Additional images

Muscles on the dorsum of the scapula, and the Triceps brachii.

[edit] References

[edit] External links

• 141230158 at GPnotebook
• Duke Orthopedics quadrangular_space
• Photo at umich.edu
• Diagram at wustl.edu
• Photo at tufts.edu
• Photo at ithaca.edu

This article was originally based on an entry from a public domain edition of Gray's Anatomy. As such, some of the information contained within it may be outdated.

This anatomy article is a stub. You can help Wikipedia by expanding it. v • d • e

v • d • e List of muscles of upper limbs (TA A04.6, GA 4.432) Shoulder deltoid · rotator cuff (supraspinatus, infraspinatus, teres minor, subscapularis) · teres major fascia: Deltoid fascia · Supraspinous fascia · Infraspinous fascia Arm (compartments) Anterior coracobrachialis · biceps brachii · brachialis Posterior triceps brachii · anconeus · Articularis cubiti Fascia Axillary sheath · Axillary fascia · Brachial fascia · intermuscular septa (Lateral, Medial) Other spaces (Quadrangular space, Triangular space, Triangular interval) Forearm Anterior superficial: pronator teres · palmaris longus · flexor carpi radialis · flexor carpi ulnaris · flexor digitorum superficialis deep: pronator quadratus · flexor digitorum profundus · flexor pollicis longus Posterior superficial: mobile wad (brachioradialis, extensor carpi radialis longus and brevis) · extensor digitorum · extensor digiti minimi · extensor carpi ulnaris deep: supinator · anatomical snuff box (abductor pollicis longus, extensor pollicis brevis, extensor pollicis longus) · extensor indicis Fascia Bicipital aponeurosis · common tendons (Extensor, Flexor) · Antebrachial fascia Other Cubital tunnel Hand Lateral volar thenar (opponens pollicis, flexor pollicis brevis, abductor pollicis brevis) · adductor pollicis Medial volar hypothenar (opponens digiti minimi, flexor digiti minimi brevis, abductor minimi digiti) · palmaris brevis Intermediate lumbrical · interossei (dorsal, palmar) Fascia posterior: Extensor retinaculum · Extensor expansion anterior: Flexor retinaculum · Palmar aponeurosis