- 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.
