Quadrilateral Space Syndrome

The borders of the quadrilateral space include the teres minor superiorly, teres major inferiorly, long head of the triceps medially, and the surgical neck of the humerus making up the lateral border.

Greg Rubin

Sports Medicine Physician · October 1, 2024 · 3 min read

Overview

The borders of the quadrilateral space include the teres minor superiorly, teres major inferiorly, long head of the triceps medially, and the surgical neck of the humerus making up the lateral border. The axillary nerve originates from the cervical nerve roots C5 and C6. The nerve then travels into the quadrilateral space where it lies superior to the posterior humeral circumflex artery.

Symptoms

The axillary nerve then divides into an anterior and posterior branch, which then innervates the deltoid and the teres minor (1,5). Anatomy of quadrilateral space Quadrilateral space syndrome is thought to occur due to compression of the posterior humeral circumflex artery (PHCA) and/or the axillary nerve. As a result, patients can have neurogenic symptoms due to axillary nerve compression or vascular complications due to compression of the posterior circumflex artery.

Causes and Risk Factors

There can also be a mixed picture where both structures are compressed. Compression can occur due to space-occupying lesion or fibrous bands in the quadrilateral space. The axillary nerve can also be injured during trauma.

Treatment Options

Injury to the posterior humeral circumflex artery can occur due to repetitive compression during abduction and external rotation. The repetitive injury can lead to thrombosis and/or aneurysm formation. Mechanism for Posterior Circumflex Humeral Artery injury Symptoms are typically described as pain and paresthesia within the superior portion of the arm.

Recovery

The paresthesias do not follow a dermatomal distribution throughout the arm and the patient can have numbness radiating down the entire arm (2,3). These symptoms are most commonly seen in overhead athletes including baseball players, swimmers, and volleyball players. The vascular manifestations include hand ischemia with pain and pallor.

When to See a Doctor

If you are experiencing symptoms that may be related to quadrilateral space syndrome, it is important to see a sports medicine physician. Early evaluation and treatment typically lead to better outcomes. Do not ignore pain or symptoms that are limiting your activity.

*This article is for educational purposes only and does not substitute for professional medical advice. Always consult a qualified healthcare provider.*

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