quadrangular space

The quadrangular space is one of the three spaces in the axillary space.

The quadrangular space is defined by:{{SUNYAnatomyLabs|03|04|01|01}} - "Scapular Region: Quadrangular Space of Scapular Region"

• above/superior: teres minor muscle.{{Cite book|last1=Pinkas|first1=D.|chapter-url=https://www.sciencedirect.com/science/article/pii/B9780323286831000370|title=Orthopaedic Physical Therapy Secrets|last2=Wiater|first2=J. M.|date=2017-01-01|publisher=Elsevier|year=2017|isbn=978-0-323-28683-1|edition=3rd|pages=318–326|language=en|chapter=37 - Functional Anatomy of the Shoulder|doi=10.1016/b978-0-323-28683-1.00037-0}}{{cite book |author1=Adam Mitchell |author2=Drake, Richard |author3=Gray, Henry David |author4=Wayne Vogl |title=Gray's anatomy for students |publisher=Elsevier/Churchill Livingstone |year=2005 |isbn=0-443-06612-4 |page=649}}
• below/inferior: teres major muscle.
• medially: long head of the triceps brachii muscle (lateral margin).
• laterally: surgical neck of the humerus.
• anteriorly: subscapularis muscle.

The quadrangular space transmits the axillary nerve, the posterior humeral circumflex artery and the posterior circumflex humeral vein.

The quadrangular space is a clinically important anatomic space in the arm as it provides the anterior regions of the axilla a passageway to the posterior regions. In the quadrangular space, the axillary nerve and the posterior humeral circumflex artery can be compressed or damaged due to space-occupying lesions or disruption in the anatomy due to trauma. Other common causes of axillary nerve compression at the quadrangular space include local compression due to osteophytes which are common in osteoarthritis, shoulder dislocations, fractures of the humeral neck, repetitive use, and external pressure (such as from crutches). Symptoms of axillary nerve compression include axillary nerve related weakness of the deltoid muscle (shoulder abduction) and teres minor (external rotation of the arm) as well as numbness of the lateral shoulder. The quadrangular space is the most common site of axillary nerve compression.{{cite journal |last1=Silver |first1=S |last2=Ledford |first2=CC |last3=Vogel |first3=KJ |last4=Arnold |first4=JJ |title=Peripheral Nerve Entrapment and Injury in the Upper Extremity. |journal=American Family Physician |date=1 March 2021 |volume=103 |issue=5 |pages=275–285 |pmid=33630556}}{{cite journal |last1=Mangi |first1=Mohammad Danish |last2=Zadow |first2=Steven |last3=Lim |first3=WanYin |title=Nerve entrapment syndromes of the upper limb: a pictorial review |journal=Insights into Imaging |date=12 October 2022 |volume=13 |issue=1 |page=166 |doi=10.1186/s13244-022-01305-5|doi-access=free |pmid=36224295 |pmc=9556688 }}

The quadrangular space is so named because the three skeletal muscles and one long bone that form its boundaries leave a space in the shape of a complete quadrangle.

The quadrangular space is also known as the quadrilateral space, the quadrilateral space of Velpeau, and the foramen humerotricipitale.

• Quadrilateral space syndrome
• Triangular space
• Triangular interval

File:Gray412-spaces.png|Muscles on the dorsum of the scapula, and the triceps brachii.

{{Gray's}}

{{reflist}}

• {{DukeOrtho|Quadrangular_space}}
• [https://web.archive.org/web/20070311211600/http://www.med.umich.edu/anatomy/plastinate/PlastinationGallery/images/UpperLimb/UL-Red/UL-Red-Pages/Image17.html Photo at umich.edu]
• [https://web.archive.org/web/20070310211822/http://www.neuro.wustl.edu/neuromuscular/pics/diagrams/quadrangsp3.jpg Diagram at wustl.edu]
• [https://web.archive.org/web/20061109013705/http://iris3.med.tufts.edu/dentgross/labguide/Shoulder4.html Photo at tufts.edu]
• [https://web.archive.org/web/20130510141404/http://www.ithaca.edu/faculty/lahr/LE2000/UE_Ind_Study_99/shoulder/edited/superficial_post.jpeg Photo at ithaca.edu]

{{Upper limb general}}

Category:Upper limb anatomy

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