SC & AC Joints

Question 1

Describe the SC joint

Answer 1

The sternoclavicular joint is the articulation of the sternum, first rib and the medial end of the clavicle.

The sternoclavicular joint links the appendicular skeleton with the axial skeleton at the upper limb

It is a saddle joint that functions like a ball and socket joint.

Question 2

What are the articulating surfaces of the SC joint?

Answer 2

The sternal / medial end of the clavicle articulates with the superior surface of the sternum, and the anterior surface of the first rib.

Question 3

What are the 3 ligaments of the sternoclavicular joint?

Answer 3

Sternoclavicular joints (anterior and posterior) connect the sternum to the clavicle. (relatively weak)

Interclavicular joint spans the jugular notch and connects left and right clavicles (relatively weak)

Costoclavicular ligament connects clavicle to costocartilage of first rib (extremely strong)

Question 4

What are the movements of the SC joint?

Answer 4

AP movement of the clavicle

elevation and depression of medial clavicle

rotation of medial clavicle

Question 5

What is the nerve supply of the SC joint?

Answer 5

medial supraclavicular nerve, and nerve to the subclavius

Question 6

Describe the AC joint

Answer 6

the acromioclavicular joint is the articulation of the lateral end of the clavicle and the acromion process of the scapula

the AC joint is a plane type of synovial joint

Question 7

What are the ligaments of the AC joint?

Answer 7

Acromioclavicular ligament (superior and inferior) - weak

Coracoclavicular ligament (trapezoid laterally and conoid medially) - one of the strongest in the shoulder

Coracoacrominal ligament (between coracoid process and acromion process

Question 8

What is the nerve supply to the AC joint?

Answer 8

Supraclavicular nerve, lateral pectoral nerve, and axillary nerve