Chapter 5: Humerus

Question 1

What does the head of the humerus articulate with?

Answer 1

With the scapula to form the shoulder joint

Question 2

What does the distal end of the humerus help form?

Answer 2

It forms part of the elbow joint

Question 3

What are the proximal anatomical structures of the humerus?

Answer 3

The head, anatomic neck, surgical neck, greater tubercle, and lesser tubercle.

Question 4

Name the distal anatomical structures of the humerus.

Answer 4

The medial epicondyle, lateral epicondyle, trochlea, capitulum, coronoid fossa, and olecranon fossa.

Question 5

Which anatomical feature is located posteriorly on the humerus and accommodates the olecranon of the ulna?

Answer 5

The olecranon fossa.

Question 6

Which two bones form the elbow joint along with the humerus?

Answer 6

The radius and ulna.

Question 7

What is the proper patient positioning for an AP projection of the humerus?

Answer 7

The patient stands or lies with the arm slightly abducted from the body, and the hand supinated.

Question 8

Where should the central ray enter for an AP humerus?

Answer 8

Perpendicular to midportion of humerus and centered to IR

Question 9

What should the collimation be for an AP humerus?

Answer 9

radiation field 2 inches distal to the elbow joint and super to the shoulder and 1 inch on the sides

Question 10

What are respiration instructions for humerus images?

Answer 10

respiration must be suspended to avoid motion in the image

Question 11

What are the evaluation criteria/structures shown for an AP humerus?

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Answer 11

Elbow and shoulder joints must be in the image

Humeral epicondyles without rotation

Humeral head and greater tubercle in profile

outline of the lesser tubercle, located between the humeral head and the greater tubercle

bony trabecular detail and surrounding soft tissues

Question 12

What is the part position for a lateral humerus? (non trauma)

Answer 12

place top border of IR approximately 1 1/2 inches above humeral head

if possible, internally rotate humerus, flex elbow 90 degrees, and rest palm of hand on hip.

coronal plane passing through epicondyles should be perpendicular to plane of IR

Question 13

Where should the central ray enter for a Lateral Humerus image?

Answer 13

perpendicular to midportion of the humerus and centered to IR

Question 14

What are the evaluation criteria/structures shown for a Lateral humerus image?

Answer 14

Elbow and shoulder joints visible, but slightly distorted due to beam divergence

superimposed humeral epicondyles

lesser tubercle in profile on medial aspect

greater tubercle superimposed over the humeral head

bony trabecular detail and surrounding soft tissues