Suprascapular Nerve Block

Excerpt

Blockade of the suprascapular nerve is an effective method for providing anesthesia and analgesia for the shoulder. The suprascapular nerve contributes to the sensory innervation of the acromioclavicular and glenohumeral joints, as well as motor innervation of the supraspinatus and infraspinatus muscles. The suprascapular nerve can be specifically targeted to provide shoulder analgesia while potentially sparing blockade of the phrenic nerve. This procedure is usually performed as an alternative to the interscalene brachial plexus block, which routinely causes hemi-diaphragmatic paralysis via phrenic nerve blockade.

There are two well-described techniques for blocking the suprascapular nerve. The first is the landmark-based posterior approach, first reported in 1941 by Wertheim and Rovenstein to treat severe chronic shoulder pain. Subsequently, nerve stimulation and ultrasound guidance have been used to identify and block the suprascapular nerve more reliably. However, the posterior approach remains challenging because of the small diameter of the nerve and its anatomic location within the suprascapular fossa, beneath the trapezius and supraspinatus muscles.

In 2012, Andreas Siegenthaler and colleagues described a novel, ultrasound-guided anterior approach to the suprascapular nerve block. This review will address the indications, sonoanatomy, technique, and potential complications for posterior and anterior approaches to blocking the suprascapular nerve.