Acromioclavicular Joint

Question 1

Articulating surfaces

Answer 1

Lateral end of clavicle

Acromion of scapula

Question 2

Joint capsule

Answer 2

Loose fibrous layer which encloses two articular surfaces
Gives rise to articular disc
Lined with synovial membrane

Question 3

Ligaments

Answer 3

Acromioclavicular - horizontally from acromion to clavicle
Conoid - vertically from coracoid process of scapula to conoid tubercle of clavicle
Trapezoid - from coracoid process to trapezoid line of clavicle
Conoid + trapezoid = coracoclavicular ligament

Question 4

Movements

Answer 4

Axial rotation
Anteroposterior movement
All movement is passive -> no muscles act directly on joint

Question 5

Neurovascular supply

Answer 5

Suprascapular artery
Thoraco-acromial artery

Suprascapular and lateral pectoral nerves

Question 6

Dislocation

Answer 6

Direct blow to joint or fall on outstretched hand
More serious is ligamental rupture occurs
If coracoclavicular ligament torn -> weight of upper limb not supported -> shoulder moves inferiorly (clavicle more prominent)
Treatment options range from ice and rest to ligament reconstruction surgery