Type 2 Superior Labral Anterior to Posterior Lesion-Related Paralabral Cyst Causing Isolated Infraspinatus Paralysis: Two Case Reports

Type 2 superior labral anterior to posterior (SLAP) lesion is a common cause of shoulder pain requiring surgical operation. SLAP tears are often associated with paralabral cysts, but they rarely cause nerve compression. However, we experienced two cases of type 2 SLAP-related paralabral cysts at the spinoglenoid notch which were confirmed as isolated nerve entrapment of the infraspinatus branch of the suprascapular nerve by electrodiagnostic assessment and magnetic resonance imaging. In these pathological conditions, comprehensive electrodiagnostic evaluation is warranted for confirmation of neuropathy, while surgical decompression of the paralabral cyst combined with SLAP repair is recommended.