A 38-year-old new mother presents with pain over the radial styloid radiating up the forearm, aggravated by lifting her infant. Pain is reproduced by holding the thumb inside a clenched fist and ulnarly deviating the wrist. The structures within the involved tendon sheath are:

• A Extensor pollicis longus and extensor pollicis brevis
• B Abductor pollicis longus and extensor pollicis brevis ✓
• C Abductor pollicis longus and flexor pollicis brevis
• D Extensor carpi radialis longus and extensor carpi radialis brevis

Explanation

This is de Quervain tenosynovitis of the first dorsal extensor compartment, containing abductor pollicis longus and extensor pollicis brevis, with a positive Finkelstein test. Extensor pollicis longus lies in the third compartment and produces a different pattern around Lister's tubercle. First-line management is thumb spica splinting with corticosteroid injection into the sheath, with surgical release reserved for refractory cases.

Reference: Campbell's Operative Orthopaedics, 14th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.