473.A woman falls on an icy sidewalk and complains of her “thumb hurt-
ing.” You take her x-ray (below) and show her there are nofractures. How-
ever, she asks you to identify the small light circles (arrow) on the x-ray are.
You explain they are sesamoid bones in the tendon of which of the following?
Extremities and Spine 571
a. Flexor pollicis longus
b. Flexor pollicis brevis
c. Adductor pollicis
d. Abductor pollicis longus
e. Abductor pollicis brevis