Suprascapular Nerve Block for Shoulder Arthroscopy
Authors: FA Barber
References: Arthroscopy 2005;21:1015
The suprascapular nerve (SSN) originates from the C5 and C6 nerve roots and provides sensation for the posterior shoulder capsule, acromioclavicular joint, subacromial bursa, and coracoclavicular ligament. Blocking it provides pre-emptive anesthesia, decreased intraoperative pain, and postoperative pain relief in shoulder arthroscopy. Under general anesthesia, 25 mL of 0.5% bupivacaine is injected by a spinal needle placed 1 cm medial to the convergence of the spine and clavicle, angling toward the coracoid. At a depth of 3 to 4 cm, the needle strikes the scapula body. The surgeon probes with the needle anteriorly until the scapula is no longer felt, then moves the needle back posteriorly until the bone is felt again. This places the needle at the coracoid base in the supraspinatus fossa where the SSN curves around the coracoid and heads to the glenohumeral joint. At this point, the anesthetic is injected, “flooding” the SSN location. In addition to the SSN block, other pain-control procedures should be performed, including bupivacaine injection of all portals and an intra-articular injection of morphine sulfate at the end of the procedure. The SSN block is an effective technique and can reduce postoperative medication needs and allow earlier patient discharge from the surgery center.
"The surgeon palpates the spine of the scapula with the arm in traction. There are several landmarks used to locate the appropriate insertion site. One way is to find a point 1 inch anterior to the junction of the middle and distal thirds of the spine. Another is to find and palpate the “soft spot” medial to the junction of the scapular spine and clavicle. The location is 1 cm medial to the convergence of the spine and clavicle, sometimes called the Neviaser portal. Place the needle at this location and advance it while angling it toward the coracoid process. At a depth of about 3 to 4 cm, the needle will strike the body of the scapula. Probe with the needle anteriorly until the scapula is no longer felt. Then move the needle back posteriorly until the bone is felt again. This will place the needle at the base of the coracoid in the supraspinatus fossa where the SSN curves around the coracoid and heads to the glenohumeral joint. At that point, 25 mL of solution is injected, flooding the area where the SSN lies."