Caused by entrapment of the abductor pollicis longus and extensor pollicis brevis tendons in the first dorsal (extensor) compartment.
Presents with radial-sided wrist pain, worse on thumb movement or gripping.
Finkelstein test is diagnostic.
Most cases resolve with splinting, NSAIDs, or steroid injection. Surgery is rare.
🧬 Pathophysiology
Inflammation and thickening of the synovial sheath surrounding the abductor pollicis longus and extensor pollicis brevis tendons.
These tendons pass through a tight fibrous tunnel near the radial styloid, leading to entrapment and pain with thumb or wrist motion.
👀 Clinical Features
Pain on the radial wrist, worsened by thumb or wrist movement
Difficulty/pain with daily activities (e.g. lifting a kettle, opening jars)
Examination findings:
Tenderness at the radial styloid
Finkelstein test: thumb is flexed across palm, fingers wrap over it, then the wrist is ulnarly deviated → positive if pain is reproduced over radial wrist
Figure 235: Finklestein test. James Heilman, MD, CC BY-SA 4.0.
💊 Management
Thumb spica splinting
NSAIDs
Corticosteroid injection into tendon sheath – often curative
Surgical release of the first extensor compartment if persistent/severe symptoms
📝 Exam Clues & Clinchers
Radial wrist pain, especially on thumb use
Positive Finkelstein test
Seen in new mothers or those frequently lifting infants
