Blood Supply of Humeral Head

Anterior Humeral Circumflex Artery (AHCA)

Origin: Axillary artery

Course:

1. Along the inferior border of subscapularis
2. Gives anterolateral ascending branch which courses along lateral aspect of bicipital groove entering the humeral head and becoming arcuate artery
3. Continues posterolaterally to anastomose with Posterior Humeral Circumflex Artery (PHCA)

Posterior Humeral Circumflex Artery (PHCA)

Origin: Axillary artery

Course:

1. Travels through quadrilateral space along with axillary nerve
2. Anastomose with PHCA
3. Posteromedially, gives branches that enter the humeral head

Contribution

1. From the older studies, there was a general consensus that anterolateral branch of AHCA was the most important source of perfusion.
2. However, recent studies have challenged this with the finding that 64% of humeral head blood supply is from the PHCA. AHCA is disrupted in 80% cases of proximal humerus fractures and PHCA remains intact in 85% cases which suggests for PHCA as the major contributor accounting for low rates of AVN.

References:

1. Proximal Humerus Fractures: Evaluation and Management edited by Lynn A. Crosby, Robert J. Neviaser