Flashcards in MSK 2.2 - Scapula And Clavicle Deck (22):
Where is the scapula located? What does it articulate with?
- Humerus at glenohumeral joint
- Clavicle at acromioclavicular joint
Give the 7 centres of ossification of the scapula
- 1 at the body
- 2 for the coracoid process
- 2 for the acromion
- 1 for vertebral border
- 1 for inferior angle
When does ossification of the scapula begin?
Around the second month of foetal life
How common are fractures of the scapula? What are fractures to this area indicators of?
- Relatively uncommon
- Indication of severe trauma to the chest from high speed road collisions or crushing injuries, for example
What causes protrusion or 'winging' of the scapula? When can this be seen?
- Damage of the long thoraic nerve due to shoulder trauma
- Can be seen when pushing the arm
Name the salient features of the costal surface of the scapula (6)
- Coracoid Process
- Supraglenoid tubercule
- Infraglenoid tubercule
- Glenoid cavity
- Subscapular Fossa
Give the salient features of the dorsal surface of the scapula (6)
- Supraspinous fossa
- Suprascapular notch
- Coracoid process
- Glenoid cavity (from lateral angle)
- Infraspinous fossa
Describe the shape of the clavicle
- S shaped
- Medial end = convex
- Lateral end = concave
Where is the clavicle located?
Between the sternum and the acromion of the scapula
What are the functions of the clavicle? (3)
- Attaches upper limb to trunk
- Protects underlying nerves and vessels for the upper limb
- Transmits force from upper limb to axial skeleton
Describe the ossification points of the clavicle
- 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
How is the clavicle clinically relevant?
- Most commonly fractured bone in the body
- Junction between medial 2/3 and lateral 1/3
How do fractures of the clavicle occur?
- 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
What are the two ends of the superior surface of the clavicle?
- Sternal end (at sternum)
- Acromial end (at acromion)
What are the two facets of the inferior surface of the clavicle?
- Sternal facet
- Acromial facet
Give two features of the sternal facet
- Articulates with Manubrium at sternoclavicular joint
- The inferior surface has an oval depression for the costoclavicular ligament
Which muscles originate from the superior surface of the clavicle? Which muscle inserts?
- Pectoralis major
What is the conoid tubercule of the superior surface of the clavicle?
The attachment point of the conoid ligament and the medical coracoclavicular ligament
What is the trapezoid line of the superior surface of the clavicle?
The attachment point of the trapezoid ligament and the lateral coracoclavicular ligament
Which muscles originate at the inferior surface of the clavicle? Which muscle inserts?
- Pectoralis major
What is the subclavian groove?
The point at which the subclavius muscle inserts