Indications

Contraindications

Clinical anatomy

The suprascapular nerve receives fibers from the fifth and sixth cervical nerve roots. It branches from the superior trunk of the brachial plexus and courses posteriorly or deep towards the scapula. It passes through the suprascapular notch under the transverse scapular ligament to enter the supraspinatus fossa. It then passes around the lateral aspect of the neck of the scapula into the infraspinous fossa. It provides sensation to the shoulder and acromioclavicular joint.

Surface anatomy

The spine of the scapula is the main bony landmark for the suprascapular block (Fig. 17.1). It can be palpated from the medial aspect of the scapula and followed laterally and superiorly to the acromion. Two centimeters superior to the midpoint of the spine of the scapula is the needle insertion point.

Figure 17.1 Landmarks for the suprascapular block. The patient is placed in the sitting or standing position with the hand of the side to be blocked placed on the opposite shoulder. This draws the scapula off the chest wall and decreases the risk of pneumothorax. The spine and medial border of the scapula are identified and marked. The midpoint of the spine of the scapula is located; 2 cm superiorly is the needle insertion point.

Sonoanatomy

An initial scan is performed in the sagittal orientation at the superior medial border of the scapula to identify the pleura. Scanning proceeds laterally with this transducer orientation. Where the scapula moves beyond the lung field is noted. The ultrasound transducer is now placed parallel to the scapular spine (Fig. 17.2) such that the scapular spine is visualized as a superficial hyperechoic line (Fig. 17.3). By moving the transducer cephalad the suprascapular fossa is identified (Fig. 17.4). While imaging the supraspinatus muscle and the bony fossa underneath, the ultrasound transducer is slowly moved laterally (maintaining a transverse transducer orientation) to locate the suprascapular notch (Fig. 17.5). The suprascapular nerve is seen as a round hyperechoic structure at 4–6 cm depth beneath the transverse scapular ligament in the scapular notch (Fig. 17.5).

Figure 17.2 Ultrasound transducer placed along the scapular spine.