Suprascapular nerve

The suprascapular nerve is the only branch of the upper trunk (C5 and C6) of the brachial plexus, supplying the supraspinatus and infraspinatus muscles and sensation to the acromioclavicular and glenohumeral joints.

Gross anatomy

Origin

The suprascapular nerve arises from the upper trunk of the brachial plexus, which is formed from the anterior rami of the fifth and sixth cervical nerves.

Course

After branching from the brachial plexus the suprascapular nerve accompanies the suprascapular artery and vein. It courses laterally and posteriorly, deep to the trapezius muscle to the superior margin of the scapula, where it passes through the suprascapular notch inferior to the superior transverse scapular ligament to enter the supraspinous fossa.

The suprascapular nerveIn the supraspinous fossa, it gives off two branches to the supraspinatus muscle before passing through the spinoglenoid notch at the lateral border of the scapula spine to pass into the infraspinous fossa, where it provides two terminal branches to the infraspinatus muscle.

Branches and supply

• motor muscular branches: supraspinatus and infraspinatus muscles

• sensory articular branches: acromioclavicular and glenohumeral joints

Relations

The suprascapular artery and vein run above the superior transverse scapular ligament.

Variant Anatomy

• 6% arising directly from ventral primary ramus of C5 without other roots contribution^3,4

• 18% having additional fibres from C4 contributing to the nerve⁴

Related pathology

• suprascapular neuropathy