Sonographic Anatomy of Finger Pulleys and Trigger Finger

Ultrasound of trigger finger (stenosing tenosynovitis) focuses on the A1 pulley at the metacarpophalangeal joint. The annular pulleys are positioned with odd numbers at joints and even numbers at phalanges. Thickening of the A1 pulley is the key finding.

• The finger has 5 annular pulleys (A1-A5) that prevent flexor tendon bowstringing; cruciform pulleys are usually not well-visualized on ultrasound.
• This is a radiology lecture covering sonographic anatomy and pathology for trigger finger diagnosis.

RadPigeon summaries are original and for information only. They are not clinical advice.