Combined intra- and extra-articular arthroscopic treatment of entrapment neuropathy of the infraspinatus branches of the suprascapular nerve caused by a periglenoidal ganglion cyst.

Entrapment neuropathy of the suprascapular nerve with pain and weakness of the affected shoulder is a rare clinical entity for which several treatment modalities have been reported. Instead of trying to evacuate the cyst from within the joint, the cyst was approached through the subacromial space after subacromial bursectomy, exposure of the spinoglenoid notch, and insertion of a small retractor through an additional posterior portal. This allowed retraction of the infraspinatus muscle together with the inferior branch of the suprascapular nerve for better visualization. After localization of the cyst and nerve, the membrane was incised and the entire viscous contents could be aspirated with a shaver. The intra-articular area of labral detachment was then repaired like a posterior aspect of a SLAP II lesion. The technique described combines the advantages of open and arthroscopic surgery, allowing one to address the underlying intra-articular pathology, completely evacuate the ganglion cyst, and protect the suprascapular nerve.