Wrist 22
TRIGGER FINGER
Thickening of either A1 Pulley and/or Nodule in superficial tendon caused by friction against A1 pulley Initially finger clicks as tendon passes under pulley Late stages finger locks in flexion
Can effect a finger or the thumb Most are of unknown cause Some are secondary to rheumatoid arthritis, gout and diabetes. Repeated and strong gripping said to predispose
IMAGING
US good at demonstrating the pulley or finger fibroma If the fibroma is in the finger it usually affects the superficial tendon Prior to the phase of true triggering, the A1 pulley may be seen to be elevated by the stiffened tendon The dynamic aspect of US can also be used to guide sheath injection
and guide percutaneous division of a pulley fibroma if one is present