Clinical History 24-year-old man with recent rock climbing injury to the left middle finger.
Ultrasound of the Month – Case 190
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Longitudinal sonographic image along the volar aspect of the left middle finger at the level of the middle phalanx (MP) shows volar displacement (double-headed arrow) of the flexor digitorum profundus tendon (FDP), no longer closely apposed to the bone. There is tenosynovial thickening (arrows), including in the expected location of the A4 pulley (arrowhead), which is not well-defined.
Ultrasound of the Month – Case 190
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Longitudinal imaging for comparison over the left ring finger volar aspect shows the flexor digitorum profundus tendon (FDP) coursing in close proximity (double-headed arrow) over the middle phalanx (MP). The A4 pulley (arrowheads) is well-defined and intact.
Ultrasound of the Month – Case 190
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Diagnosis: Left Middle Finger A4 Pulley Rupture Flexor tendon pulleys are areas of flexor tendon sheath thickening that help to anchor the tendons to their underlying bone, with 5 annular pulleys (A1-A5) and 3 cruciate pulleys (C1-C3) in each finger. Pulley injuries occur in rock climbers due to excessive mechanical stresses on their fingers (climber’s finger). The most common isolated pulley ruptures involve the A2 pulley, followed by the A4 pulley. Ultrasound can visualize the annular pulleys and flexor tendons and is therefore implemented in the diagnosis of pulley rupture.
Ultrasound of the Month – Case 190
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