THE ANASTOMOSES AROUND THE SCAPULA

The anastomoses around scapula is an arterial anastomosis around both surfaces of scapula bone between the branches of subclavian and axillary arteries. The arteries taking part in this anastomoses are‐
1. The suprascapular artery from thyrocervical trunk of first part of subclavian artery. The artery reaches upper border of scapula and passes above suprascapular ligament to reach supraspinous fossa, then it curves around spinoglenoid notch to reach infraspinous fossa.
2. The deep branch of transverse cervical artery‐also from thyrocervical trunk. The artery descends along medial border of scapula deep to levator scapulae and rhomboids (sometimes the artery arises from third part of subclavian artery and is known as dorsal scapular artery).
3. The subscapular artery from third part of axillary. Its circumflex scapular branch passes between the two origins of teres minor, enters infraspinous fossa. Another branch accompanies the thoraco‐dorsal nerve. Functional importance
a. The anastomoses provides sufficient amount of blood to scapular muscles and upper extremity during movements of shoulder joint from lateral border of scapula on its dorsal surface.
b. In case of blockage of main arterial trunk‐distal to the origin of thyrocervical trunk and proximal to the origin of subscapular artery, this anastomoses provides an alternative route for the supply of blood to upper extremity.