Trigger thumb

Trigger thumb (or flexor pollicis longus stenosing tenosynovitis) is a specific type of trigger finger involving the thumb.

Clinical presentation

May present as a transient locking of the thumb in flexion, followed by a painful snapping sensation during extension

Radiographic features

Ultrasound / MRI

Can show varying degrees of flexor pollicis longus tendinosis (local swelling of the flexor tendons distal to the pulley) with a distinct nodule, A1 pulley thickening, and tenosynovitis. Small cysts may be present at the pulley boundaries due to fluid trapping.

Dynamic scanning during passive flexion and extension could show difficult tendon gliding underneath the abnormal pulley

Doppler imaging may depict hypervascularity in the region of the pulley and surrounding soft tissues

Article information

rID: 58508
Synonyms or Alternate Spellings:
  • Stenosing tenosynovitis of flexor pollicis longus
  • Flexor pollicis longus stenosing tenosynovitis
  • FPL stenosing tenosynovitis

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Cases and figures

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