Reverse total shoulder arthroplasty restores function in cuff tear arthropathy by medialising and inferiorly displacing the centre of rotation. Which structure must be functional for this procedure to succeed?

• A Supraspinatus tendon
• B Long head of biceps tendon
• C Teres minor and infraspinatus as a pair
• D Deltoid muscle with an intact axillary nerve ✓

Explanation

By reversing ball-and-socket geometry, reverse shoulder arthroplasty increases the moment arm and tension of the deltoid, which then elevates the arm in place of the deficient rotator cuff. A working deltoid supplied by an intact axillary nerve is therefore mandatory. The supraspatus is by definition torn in this condition, and absence of external rotators causes postoperative lack of active external rotation rather than precluding the operation itself.

Reference: Rockwood and Green's Fractures in Adults companion text Campbell's Operative Orthopaedics, 14th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.