Upper Limb - Bones (1)

Question 1

What is the “intertubercular sulcus” of the humerus, and what is another name for it?

Answer 1

Also called the “bicipital groove”, it is the groove running down the anterior surface of the proximal humerus, between the greater tubercle and the lesser tubercle, where the tendon of the long head of biceps lies (beneath the transverse humeral ligament).

Question 2

Which is more distal, the anatomical neck or the surgical neck of the humerus?

Answer 2

The surgical neck.

Question 3

Why is the surgical neck of the humerus named so?

Answer 3

Because fractures occur far more often at the surgical neck than at the anatomical neck.

Question 4

What is the clinical significance of a supracondylar fracture of the humerus?

Answer 4

These occur most commonly in children in a FOOSH injury, and they are important to understand because of the risk of interruption of the brachial artery, which runs anteriorly to the humerus.

Question 5

Name the articulations of the elbow joint.

Answer 5

Humeroulnar (trochlea) and Humeroradial (capitulum). Note that the proximal radioulnar joint is not part of the elbow joint.

Question 6

Name the two surfaces of the distal humerus that articulate at the elbow joint.

Answer 6

The capitulum is the lateral surface, which articulates with the radius. The trochlea is the medial surface, which articulates with the ulna.

Question 7

Name the three fossae of the distal humerus.

Answer 7

The **coronoid **fossa, the **radial **fossa, and the **olecranon **fossa.

Question 8

Classify the humeroulnar joint, the humeroradial joint, and the proximal radioulnar joint.

Answer 8

The humeroulnar joint is a hinge joint and the humeroradial joint is a limited ball-and-socket joint. The proximal radioulnar joint is a pivot joint.

Question 9

Name the three ligaments of the elbow joint.

Answer 9

Radial colleteral ligament, Ulnar collateral ligament, Annular ligament.

Question 10

Name the two major membranes of the elbow joint, and what structure separates them?

Answer 10

The **fibrous membrane/capsule **is separated from the **synovial membrane **by the fat pads.

Question 11

Describe the bones making up the pectoral girdle.

Answer 11

The pectoral girdle consists of the scapulae and clavicles, connected to the manubrium of the sternum. There is a posterior gap in this bony “ring”.

Question 12

At which part of the clavicle is its weakest point, where it is most commonly fractured?

Answer 12

At the junction of the middle and lateral thirds.

Question 13

What is different about the structure of the clavicle compared to other long bones?

Answer 13

There is no medullary cavity.

Question 14

On the humeral head, which is more lateral: The greater tubercle or the lesser tubercle?

Answer 14

Greater tubercle = Lateral. Lesser tubercle = Medial.

Question 15

What connects the radius and the ulna along their shafts?

Answer 15

The interosseous membrane.

Question 16

What is the major difference between the distal ends of the ulna and radius, in terms of their articulations?

Answer 16

The distal end of the radius articulates with the carpal bones (the radio-carpal joint), whereas the distal end of the ulna does not reach the wrist, and does not articulate with the carpal bones.

Question 17

What is a Colles fracture, and in which population is it most common?

Answer 17

Complete transverse fracture through the distal 2cm of the radius. There is a dinner fork deformity. Most commonly occurs in females over 50yo, due to osteoporosis, and occurs in FOOSH.

Question 18

Name the carpal bones, in order, starting at the most proximal and most radial bone.

Answer 18

Scaphoid, Lunate, Triquetrum, Pisiform.

Trapezium, Trapezoid, Capitate, Hamate.

Question 19

Which carpal bone articulates with the 5th metacarpal?

Answer 19

Hamate.

Question 20

Which is the most frequently fractured carpal bone?

Answer 20

Scaphoid.

Question 21

Which section of the fractured scaphoid is at risk of avascular necrosis?

Answer 21

The proximal fragment.

Question 22

Name as many parts of the following bones that are palpable in a healthy 25yo: Clavicle, Scapula, Humerus.

Answer 22

Entire superior border of clavicle.

Acromion, and acromioclavicular joint.

Entire crest of scapular spine.

Entire medial and inferior borders of scapula.

Greater tubercle of humerus.

Lateral and Medial epicondyles of humerus.

Question 23

Name as many parts of the following bones that are palpable in a healthy 25yo: Ulna, Radius, Carpal bones, Bones of the hand.

Answer 23

Olecranon, and the entire posterior border of Ulna.

Styloid processes of Ulna and Radius.

Pisiform. Hook of Hamate. Capitate.

All metacarpals and phalanges.

Question 24

Explain the anatomy of the annular ligament of the elbow joint.

Answer 24

The annular ligament of the radius encircles the head of the radius, with end attachments at the ulna. This keeps the head of the radius in the radial notch of the ulna, at the proximal radio-ulnar joint.

Question 25

Which of the carpal bones is the first to have its ossification centre appear in life? In which year?

Answer 25

Capitate. In the first year.

Question 26

Which of the carpal bones is the last to have its ossification centre appear in life? In which year?

Answer 26

Pisiform. 10th year.

Question 27

What is the CRITOE mnemonic?

Answer 27

This is the order of appearance of ossification centres (but not complete ossification) of the elbow:

Capitulum (1 year)

Radial head (3 years)

Inner (medial) epicondyle (5 years)

Trochlea (7 years)

Olecranon (9 years)

External (lateral) epicondyle (11 years)