A volleyball player presents with insidious onset of weakness of external rotation of the shoulder and wasting over the infraspinous fossa, with normal strength of initiating abduction. MRI shows a ganglion cyst at the spinoglenoid notch. Which nerve is compressed?
- A Axillary nerve
- B Dorsal scapular nerve
- C Suprascapular nerve distal to the suprascapular notch ✓
- D Upper subscapular nerve
Correct answer: C. Suprascapular nerve distal to the suprascapular notch
Explanation
The suprascapular nerve from the upper trunk (B5, B6) passes through the suprascapular notch, supplying supraspinatus, then winds around the spinoglenoid notch to supply infraspinatus. A cyst at the spinoglenoid notch compresses only the infraspinatus branch, giving isolated external rotation weakness with preserved abduction initiation. Compression at the suprascapular notch itself would also weaken supraspinatus.
Reference: Moore's Clinically Oriented Anatomy, 9th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.