Trigger Finger involves which mechanism?

• A. Pain in the wrist during flexion.
• B. Finger attempts to snap closed due to inflammation and scarring around the tendon.
• C. Numbness in the little finger only.
• D. Discoloration of the skin on the finger.

Answer: (B)

Trigger finger is caused by stenosing tenosynovitis of the flexor tendon, where inflammation and scarring around the tendon sheath narrow the passage the tendon must glide through, especially at the pulley system. This makes the tendon bulky or nodular, so it can’t slide smoothly as the finger flexes. When the finger tries to bend, the tendon catches behind the narrowed pulley and then suddenly snaps forward, producing the characteristic “snap” or locking sensation as the finger moves. That mechanism—inflammation and scar tissue around the tendon causing it to snap closed due to restricted glide—best explains trigger finger. The other options describe symptoms not about the tendon’s gliding path: wrist pain during flexion isn’t the primary mechanism, numbness in a single finger points to nerve involvement, and skin discoloration isn’t typical of this condition.