Trigger finger is stenosing tenosynovitis of which pulley?

Trigger finger is stenosing tenosynovitis of which pulley?

• A. A2 pulley
• B. A3 pulley
• C. A1 pulley
• D. Cruciate pulley

Answer: (C)

Trigger finger results from narrowing of the flexor tendon sheath where the tendon passes under the first annular pulley, known as the A1 pulley. This pulley sits at the level of the metacarpophalangeal joint and helps guide the tendon as the finger flexes. When the A1 pulley becomes thickened or nodular, it constricts the tendon’s glide, so the finger can’t smoothly flex or extend, leading to catching or locking—this is the hallmark of trigger finger. The other pulleys (A2 at the middle phalanx, A3 at the proximal interphalangeal joint, and the cruciate pulleys) can be involved in other problems, but the most common site for stenosing tenosynovitis causing trigger finger is the A1 pulley.

Trigger finger results from narrowing of the flexor tendon sheath where the tendon passes under the first annular pulley, known as the A1 pulley. This pulley sits at the level of the metacarpophalangeal joint and helps guide the tendon as the finger flexes. When the A1 pulley becomes thickened or nodular, it constricts the tendon’s glide, so the finger can’t smoothly flex or extend, leading to catching or locking—this is the hallmark of trigger finger. The other pulleys (A2 at the middle phalanx, A3 at the proximal interphalangeal joint, and the cruciate pulleys) can be involved in other problems, but the most common site for stenosing tenosynovitis causing trigger finger is the A1 pulley.