Extensor Pollicis Longus     

- See: Extensor Pollicis Longus Rupture:

- Anatomy:
    - origin: posterior surface of the middle 1/3 of the ulna & interosseous  membrane;
    - insertion: posterior surface of the base of the distal phalanx of thumb;
    - action: extends the distal phalanx of the thumb; continued action, extends proximal phalanx and adducts the 1st metacarpal;
    - nerve: PIN branch of deep radial nerve,   C6, C7, & C8;

- Tunnel III:
    - on ulnar side of Lister's Tubercle contains EPL , which defines ulnar border of anatomic snuff box;
         - EPL tendon takes 45 deg turn around Lister's tubercle;
    - then after passing over ECRL  & ECRB  tendons of tunnel I, it continues along its course to the thumb;
          - note: that the "cross over" between the EPL and the ECR tendons can become involved in a cross over syndrome, just distal to the
                 extensor retinaculum;

- Exam:
    - palpate length of tendon, look for any signs of rupture;
    - ask pt to place hand flat on table, & lift only thumb off surface;
         - w/ rupture, patient will be unable to raise the thumb in line w/ the second metacarpal

  Extensor pollicis longus opposition transfer.

  Effects of extensor pollicis longus transposition and extensor indicis proprius transfer to extensor pollicis longus on thumb mechanics.

Original Text by Clifford R. Wheeless, III, MD.

Last updated by Data Trace Staff on Thursday, December 15, 2011 10:54 am