Plastic Surgery>>>>>Hand surgery
Question 8#

Of the bones in the carpus:

A. The scaphoid is the largest bone
B. 40% of the blood supply of the scaphoid enters via the waist of the bone
C. 40% of the scaphoid surface is covered with articular cartilage
D. The kinetic forces of the carpus produce a tendency for the scaphoid to extend
E. Scapholunate dissociation is followed by flexion of the scaphoid

Correct Answer is E

Comment:

Scapholunate dissociation is followed by flexion of the scaphoid. The capitate is the largest of the carpal bones. 80% of the scaphoid blood supply enters at the waist (hence the predilection to non-union of a proximal pole fracture) and 80% of the scaphoid surface is covered in articular cartilage. The kinetic forces of the carpus produce a tendency for the scaphoid to flex. The scaphoid moves into flexion if it is released from the lunate by laxity or rupture of the scapholunate ligament.