Acromioclavicular Joint

Question 1

What type of joint is the acromioclavicular joint?

Answer 1

Plane synovial

Question 2

What is the function of the joint?

Answer 2

To connect the scapula to the clavicle

Question 3

What are the articular surfaces of the joint?

Answer 3

Clavicle and Acromion

Question 4

Describe the relation of the articular surfaces?

Answer 4

Flat facet at the lateral end of the clavicle with a flat facet on the anteromedial surface of the acromion

Question 5

Is the clavicular surface convex or concave?

Answer 5

Convex

Question 6

Is the acromion surface convex or concave?

Answer 6

Concave

Question 7

What is the articular surfaces covered in?

Answer 7

Fibrocartilage

Question 8

Describe the capsule?

Answer 8

Loose fibrous capsule

Question 9

The capsule is thickest and strongest when it is reinforced by?

Answer 9

Trapezius

Question 10

What lines the inner surface of the joint capsule?

Answer 10

Synovial membrane

Question 11

What is the intra-articular structure involved in the joint?

Answer 11

Fibrocartilaginous Articular disc

Question 12

What is the role of the articular disc?

Answer 12

To divide the joint cavity

Question 13

What can the articular disc compensate for?

Answer 13

Small degree of incongruence between the articular surfaces

Question 14

What are the ligaments involved in the joint?

Answer 14

Superior and Inferior acromioclavicular ligaments and coracoclavicular ligament

Question 15

What are the two divisions of the coracoclavicular ligament?

Answer 15

Conoid and trapezoid

Question 16

What is the stonger part of the coracoclavicular ligament?

Answer 16

Trapezoid

Question 17

What limits anterior movement of the scapula?

Answer 17

Conoid

Question 18

What limits posterior movement of the scapula?

Answer 18

Trapezoid

Question 19

What does the coracoclavicular ligament do?

Answer 19

Prevents the acromion from sliding inferomedially under the lateral end of the clavicle

Question 20

What is involved in the stability of the joint?

Answer 20

Coracoclavicular ligament, trapezius and deltoid muscles and capsular thickenings

Question 21

Protraction is limited by?

Answer 21

Trapezoid part of coracoclavicular ligament

Question 22

Retraction is limited by?

Answer 22

Conoid part of coracoclavicular ligament

Question 23

ROM for elevation and depression?

Answer 23

less than 15 degrees

Question 24

Elevation is limited by?

Answer 24

Tension in both parts of the coracoclavicular ligament

Question 25

Depression is limited by?

Answer 25

Coracoid process contacting inferior surface of the clavicle

Question 26

What is axial rotation associated with?

Answer 26

Medial and lateral rotation of scpaula

Question 27

What does axial rotation allow?

Answer 27

A flexed arm to become fully elevated

Question 28

What is axial rotation limited by?

Answer 28

Both parts of coracoclavicular ligament