F. Alan Barber M.D.
Plano Orthopedic and Sports Medicine Center, Plano, Texas, U.S.A
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.
Arthroscopy: The Journal of Arthroscopic & Related Surgery Volume 21, Issue 8 , August 2005, Pages 1015.e1-1015.e4.