The suprascapular nerve is anaesthetized deep to the omohyoid muscle with ultrasound-guidance

The suprascapular nerve runs relatively close to the divisions of the brachial plexus in this location implying a risk of medial spread of local anaesthetic to the brachial plexus

Ref: Siegenthaler et al. (2012)

Place the patient supine with the head turned contralateral

Place a high-frequency linear probe in the axial plane visualizing the transverse process of C6 with its prominent anterior tubercle (Chassaignac’s tubercle); check that the transverse process of C7 has no anterior tubercle to validate the correct level

Move the probe cranial and identify the C5 nerve root between the anterior and posterior tubercles of the transverse process of C5; follow the C5 nerve root peripherally until it fuses with the C6 nerve root and becomes the superior trunk

Visualize the suprascapular nerve as it branches off postero-laterally from the proximal part of the superior trunk and dives under the omohyoid muscle (see next page)

Insert the needle in-plane from the posterior/lateral end of the probe and inject 5 mL of local anaesthetic perineurally

The nerve roots of C5 and C6 fuse and become the superior trunk of the brachial plexus

The suprascapular nerve typically branches off the superior trunk immediately after the fusion from the nerve roots of C5 and C6

Other nerves from the superior trunk: the subclavian nerve

Other nerves from the C5 nerve root: the long thoracic nerve, the dorsal scapular nerve

Other nerves from the C6 nerve root: the long thoracic nerve (which branches off the nerve roots from C5, C6 and C7)

The anterior tubercle of the transverse process of the C6 vertebra is prominent and is called “Chassaignac’s tubercle”

The transverse process of the C7 vertebra has no anterior tubercle

The supraspinatus muscle is located in the supraspinous fossa above the scapular spine, and the infraspinatus muscle is located in the infraspinous fossa below the scapular spine

The supra- and infraspinatus muscles are innervated by the suprascapular nerve; they are lateral rotators of the shoulder joint and initiators of shoulder abduction

The suprascapular block is indicated for postoperative analgesia after shoulder surgery when interscalene brachial plexus block is contraindicated

The suprascapular nerve origins from the superior trunk of the brachial plexus

It runs under the superior transverse scapular ligament and innervates the supraspinatus and infraspinatus muscles

The superior transverse scapular ligament creates a bridge across the scapular notch and converts the notch to an aperture

The suprascapular nerve runs below the ligament

The suprascapular artery and vein pass superior across the ligament

The deep cervical plexus is sandwiched between the upper part of the medial scalene muscle and the longus capitis muscle and it consists of:

– Ansa cervicalis – a cervical plexus loop with a superior and an inferior root.
The superior root is a branch of the C1 ventral ramus. It briefly joins the hypoglossal nerve.
The inferior root is derived from branches of the C2 ventral rami.

The superior root descends on the carotid sheath. It innervates the superior belly of the omohyoid muscle and the upper parts of the sternothyroid and sternohyoid muscles before it unites with the inferior root. The inferior root of the ansa cervicalis is derived from branches of the C2 and C3 ventral rami. It innervates the inferior belly of the omohyoid muscle and the inferior parts of the sternothyroid and sternohyoid muscles.

– Phrenic nerve from C3-C5 innervates the diaphragm and the pericardium
– Branches from C1-C4 innervate the anterior and middle scalene muscles

At the level of the transverse process of vertebral body C6, both the anterior and middle scalene muscles are prominent, while the capitis longus muscle is inconspicous and located just lateral to the colli longus muscle

The anterior scalene muscle is attached to the anterior tubercles and the middle scalene muscle to the posterior tubercles of the transverse processes

At the level of the transverse process of vertebral body C4, the anterior scalene muscle has tapered while the cross section of the capitis longus muscle has become more prominent; the sympathetic trunk runs anterior to the capitis longus muscle

The picture on the right shows an axial view at the level of vertebral body C6 with the C5 and C6 cervical spinal nerve roots (magenta and green dots in upper picture) and C4 with the C3 and C4 roots (white and yellow dots in lower picture)

Place the probe in the axial plane at the level of the transverse proces of vertebral body C4

The needle is advanced with in-plane technique from the posterior end of the probe until it penetrates the prevertebral fascia and the needle tip is placed just posterior to the longus capitis muscle

A lateral view of the point of emergence of the nerves of the superficial cervical plexus at the postero-lateral margin of the sternocleidomastoid muscle, where the nerves pierce the superficial cervical fascia to become subcutaneous