475.The answer is a.(Moore and Dalley, pp 566, 682.)Fractures of the
femoral neck, commonly called “hip fractures” are extremely common in
older women as a consequence of osteoporosis. Since the woman was still
able to bear some weight on her leg it is very unlikely that she had com-
plete displacement of the femoral neck (answer b),rather a compression
fracture with the fall. None of the symptoms are consistent with fracture in
either the shaft (answer c)or distal portion (answers d and e)of the
femur.
476.The answer is e.(Moore and Dalley, pp 21–22, 729–730.)The clavi-
cle is the most frequently broken bone in body. Greenstick fractures of the
clavicle are extremely common in children as a result of falling on out-
stretched arms. Colles’ fracture is also common from falling on out-
stretched arms, but there are no physical findings to support a Colles’
fracture [(answer a);fracture of the distal radius, occasionally including
the ulna] in this boy, [nor scaphoid fracture (answer b)]. The sternoclavic-
ular joint (answer d)is extremely stable and is rarely dislocated. Fracture
of the surgical head of the humerus (answer c)isnotindicated by the
physical findings.
477.The answer is d.(Moore and Dalley, pp 733–734.)Breaks of the mid-
shaft of the humerus are most likely to damage the radial nerve and deep
artery of the arm (profunda brachii artery). The radial nerve (answer c)
runs within the radial groove on the posterior surface of the humerus (mid-
shaft) along with the deep artery of the arm. Because the radial nerve inner-
vates all the extensors of the arm and forearm, the observation that the
teenager suffers from wrist drop is expected. Normally the nerve to the pos-
terior compartment of the arm, the extensors of the elbow joint, will be
spared in such an injury. Since the left forearm and hand felt slightly
cooler than the right this suggests that the deep artery of the arm is also
compromised by the displaced fracture. The axillary nerve damage
(answers a and b)would result in reduced shoulder movement, which is
normal. The median nerve and brachial artery (answer e),run along the
medial aspect of the arm.
478.The answer is b.(Moore and Dalley, pp 566, 682.)Fractures of the
femoral neck (cervical) will completely interrupt the blood supply to the
femoral head in adults. If the capsular retinaculum also is torn, avascular
596 Anatomy, Histology, and Cell Biology