Suprascapular nerve compression is rare and should be considered in the differential diagnosis of patients with shoulder pain and lateral rotation strength deficit. Spinoglenoidal cyst may be the reason for compression and a posterior superior glenoid lip rupture may be the most probable hypothesis for their appearance. Magnetic resonance imaging and electromyography define the diagnosis. Indirect arthroscopic decompression of the cyst and repair of glenoid lip allow for a neurologically complete recovery. The authors report two cases of isolated paralysis of the infraspinatus muscle caused by compression of spinoglenoids cysts treated by arthroscopy, as well as its pre- and post-operative assessment.
Scapula; Muscle atrophy; Nerve compression syndromes; Cysts; Arthroscopy