Which condition is described as a stenosing tenosynovitis of the flexor tendon sheath at the A1 pulley?

• A. Trigger finger
• B. De Quervain's tenosynovitis
• C. Dupuytren's contracture
• D. Carpal tunnel syndrome

Answer: (A)

This describes trigger finger. The condition is a stenosing tenosynovitis of the flexor tendon sheath at the A1 pulley, which is the pulley located near the base of the finger at the level of the metacarpophalangeal joint. Thickening of the pulley or of the flexor tendon causes friction and a mechanical catch as the finger flexes, producing a “triggering” or locking sensation. Clinically, people may feel a catch or hear a snap, and there can be a palpable nodule over the palm where the tendon glides through the pulley.

De Quervain’s tenosynovitis involves the first dorsal (thumb) compartment and causes radial wrist and thumb-side pain. Dupuytren’s contracture is a palmar fascia thickening leading to flexion contractures of the fingers. Carpal tunnel syndrome is median nerve compression at the wrist, presenting with numbness, tingling, and weakness in the hand.