A 4-year-old child is brought to the emergency department with refusal to move the left arm after the mother lifted the child by the hand while crossing a road. The arm is held in slight flexion and pronation. Which anatomical structure is primarily responsible for this injury, known as nursemaid's elbow?

• A Ulnar collateral ligament
• B Annular ligament of the radius ✓
• C Quadrate ligament
• D Interosseous membrane of the forearm

Explanation

Nursemaid's elbow (radial head subluxation) occurs when a longitudinal traction force on the extended, pronated forearm causes the annular ligament to slip over the radial head. In young children, the annular ligament is relatively loose and the radial head is small and oval-shaped, allowing the ligament to become trapped between the radial head and capitulum. Reduction involves supination of the forearm.

Reference: Rockwood and Wilkins' Fractures in Children, 9th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.