MSK 2.2 - Scapula And Clavicle

Question 1

Where is the scapula located? What does it articulate with?

Answer 1

• Back
• Humerus at glenohumeral joint
• Clavicle at acromioclavicular joint

Question 2

Give the 7 centres of ossification of the scapula

Answer 2

• 1 at the body
• 2 for the coracoid process
• 2 for the acromion
• 1 for vertebral border
• 1 for inferior angle

Question 3

When does ossification of the scapula begin?

Answer 3

Around the second month of foetal life

Question 4

How common are fractures of the scapula? What are fractures to this area indicators of?

Answer 4

• Relatively uncommon

- Indication of severe trauma to the chest from high speed road collisions or crushing injuries, for example

Question 5

What causes protrusion or ‘winging’ of the scapula? When can this be seen?

Answer 5

• Damage of the long thoraic nerve due to shoulder trauma

- Can be seen when pushing the arm

Question 6

Name the salient features of the costal surface of the scapula (6)

Answer 6

• Coracoid Process
• Acromion
• Supraglenoid tubercule
• Infraglenoid tubercule
• Glenoid cavity
• Subscapular Fossa

Question 7

Give the salient features of the dorsal surface of the scapula (6)

Answer 7

• Supraspinous fossa
• Suprascapular notch
• Coracoid process
• Acromion
• Glenoid cavity (from lateral angle)
• Infraspinous fossa

Question 8

Describe the shape of the clavicle

Answer 8

• S shaped
• Medial end = convex
• Lateral end = concave

Question 9

Where is the clavicle located?

Answer 9

Between the sternum and the acromion of the scapula

Question 10

What are the functions of the clavicle? (3)

Answer 10

• Attaches upper limb to trunk
• Protects underlying nerves and vessels for the upper limb
• Transmits force from upper limb to axial skeleton

Question 11

Describe the ossification points of the clavicle

Answer 11

• Ossifies from 3 centres
• A medial and a lateral for the body that appear around week 5-6 of foetal life
• A secondary for the sternal end that appears around at age 18-20 and unites with the rest of the bone at around age 25

Question 12

How is the clavicle clinically relevant?

Answer 12

• Most commonly fractured bone in the body

- Junction between medial 2/3 and lateral 1/3

Question 13

How do fractures of the clavicle occur?

Answer 13

• Results from a fall on the shoulder/outstretched hand
• The lateral end is displaced inferiorly by the arm
• The medial end is displaced by the pectoralis major and pulled superiorly by the sternocleidomastoid muscle

Question 14

What are the two ends of the superior surface of the clavicle?

Answer 14

• Sternal end (at sternum)

- Acromial end (at acromion)

Question 15

What are the two facets of the inferior surface of the clavicle?

Answer 15

• Sternal facet

- Acromial facet

Question 16

Give two features of the sternal facet

Answer 16

• Articulates with Manubrium at sternoclavicular joint

- The inferior surface has an oval depression for the costoclavicular ligament

Question 17

Which muscles originate from the superior surface of the clavicle? Which muscle inserts?

Answer 17

• Pectoralis major
• Sternocleidomastoid
• Deltoid
• Trapezius

Question 18

What is the conoid tubercule of the superior surface of the clavicle?

Answer 18

The attachment point of the conoid ligament and the medical coracoclavicular ligament

Question 19

What is the trapezoid line of the superior surface of the clavicle?

Answer 19

The attachment point of the trapezoid ligament and the lateral coracoclavicular ligament

Question 20

Which muscles originate at the inferior surface of the clavicle? Which muscle inserts?

Answer 20

• Sternohyoid
• Pectoralis major
• Deltoid
• Subclavian

Question 21

What is the subclavian groove?

Answer 21

The point at which the subclavius muscle inserts

Question 22

Describe the shape of the scapula

Answer 22

Triangular