UL1 - Clinical

Question 1

which nerve is commonly affected in a surgical neck fracture of the humerus?

Answer 1

axillary nerve

Question 2

what structures are at risk in a surgical neck fracture of the humerus?

Answer 2

axillary nerve
posterior circumflex humeral arteries

Question 3

sensory and motor consequences of damage to the axillary nerve?

Answer 3

motor damage - weakness/ paralysis of the deltoid muscle, causes difficulty with arm abduction

sensory damage - reduced sensation in the regimental badge area (superolateral aspect of the arm)

Question 4

what structures are at risk in a mid-shaft humerus fracture?

Answer 4

radial nerve
profunda brachii artery

Question 5

sensory and motor consequences of damage to the radial nerve?

Answer 5

sensory damage - reduced sensation in the posterior arm, forearm, and hand

motor damage - wrist drop due to paralysis of wrist extensors

Question 6

why may wrist drop occur following a mid-shaft humerus fracture?

Answer 6

damage to the radial nerve can cause paralysis of wrist extensors - leads to wrist drop

Question 7

in what type of humerus fracture may reduced sensation in the regimental badge area occur?

Answer 7

surgical neck fracture of the humerus

Question 8

what nerve is at risk in a distal humeral fracture?

Answer 8

median nerve

Question 9

what nerve is at risk with an avulsion fracture of the medial epicondyle?

Answer 9

ulnar nerve

Question 10

clinical (sensory & motor) consequences of an avulsion fracture of the medial epicondyle?

Answer 10

motor damage - weakness in muscles innervated by the ulnar nerve (e.g. intrinsic hand muscles)

sensory damage - reduced sensation along the ulnar aspect of the hand and forearm

Question 11

what is the characteristic motor deficit of a radial nerve injury in a mid-shaft humerus fracture?

Answer 11

wrist drop due to paralysis of wrist extensors

Question 12

(!!) describe the motor functional implications of an avulsion fracture of the medial epicondyle, and why

Answer 12

weakness or paralysis in intrinsic hand muscles as they’re innervated by the ulnar nerve - can reduce grip strength

Question 13

(!!) how does the anatomical location of the radial nerve in the radial groove contribute to the specific deficits seen in a mid-shaft humerus fracture?

Answer 13

the radial nerve spirals along the radial groove of the humerus - it’s vulnerable to damage in fractures of the mid-shaft

this can lead to:
- wrist drop due to paralysed/damaged wrist extensors
- reduced sensation in the posterior arm, forearm and hand

Question 14

where is sensation often reduced/ affected with mid-shaft humeral fractures?

Answer 14

posterior arm, forearm and hand

Question 15

An 84-year-old man injures his arm while skiing. An x-ray film taken in the emergency department indicates a fracture that has displaced the greater tubercle of the humerus. Movements of the humerus most likely affected by this injury would include which of the following?

Answer 15

abduction & lateral rotation

Question 16

A 32-year-old woman undergoes a right mastectomy for cancer. After her operation, she complains to her physician that when she pushes her arms against the wall her right scapula protrudes posteriorly away from the thoracic wall. Injury to which of the following nerves would most likely cause this problem?

Answer 16

long thoracic nerve