title: Safe treatment of trigger thumb with longitudinal anatomic landmarks.
abstract: OBJECTIVE
  Stenosing tenosynovitis of the thumb flexor tendon sheath is also known as trigger thumb. It is an inflammatory process that involves the flexor tendon sheath at the A1 pulley. Successful percutaneous or open treatment of trigger thumb depends on the ability of the clinician to properly predict the location of the A1 pulley. Longitudinal anatomic landmarks can facilitate safe treatment for the trigger thumb while circumventing injury to the neurovascular bundles.
  
  
  METHODS
  Fourteen fresh cadaveric hands were dissected to identify surface landmarks corresponding to the oblique course of the flexor pollicis longus tendon at the level of the A1 pulley.
  
  
  RESULTS
  The longitudinal landmarks for the A1 pulley of the thumb are the palpable hook of the hamate and the midline of the thumb interphalangeal (IP) crease. Other bony prominences, such as the pisiform bone did not serve as effective landmarks while the thumb was in an abducted position.
  
  
  CONCLUSIONS
  we encourage the use longitudinal anatomic landmarks to predict the location of the thumb A1 pulley. The hook of the hamate and the midline at the palmar interphalangeal crease are reliable landmarks for safe release of the A1 pulley while avoiding inadvertent injury to adjacent structures.
authors.affiliation: Division of Plastic and Reconstructive Surgery, University of Louisville School of Medicine, Kentucky.
authors.forename: Ron
authors.initials: R
authors.lastname: Hazani
authors.forename: Ryan D
authors.initials: RD
authors.lastname: Whitney
authors.forename: Jeremiah
authors.initials: J
authors.lastname: Redstone
authors.forename: Saeed
authors.initials: S
authors.lastname: Chowdhry
authors.forename: Bradon J
authors.initials: BJ
authors.lastname: Wilhelmi