Case Report: Spinoglenoid notch cysts associated with type II SLAP lesions: a report of two cases and review of the literature

Background Spinoglenoid notch cysts associated with type II superior labrum anterior-to-posterior (SLAP) lesions are an uncommon cause of suprascapular nerve compression. Case Presentation This report presents two patients with posterior shoulder pain, weakness of inverted glenohumeral external rotation, and isolated infraspinatus atrophy. Magnetic resonance imaging confirmed spinoglenoid notch cysts communicating with type II SLAP lesions in both cases. Both patients underwent arthroscopic labral repair through standard SLAP portals, with intra-articular decompression of the cysts through the pre-existing capsular defect, avoiding additional dissection within the spinoglenoid notch. Postoperative rehabilitation and follow-up imaging demonstrated complete resolution of the cysts, restoration of infraspinatus muscle bulk, and recovery of external rotation strength. Conclusions These cases demonstrate that arthroscopic labral repair, combined with indirect cyst decompression, can achieve complete cyst resolution and muscle recovery for selected patients. The findings support the potential reversibility of compression-related muscle atrophy following timely nerve decompression and emphasize the importance of accurate diagnosis and individualized management.