Acromioclavicular Joint Flashcards
(28 cards)
What type of joint is the acromioclavicular joint?
Plane synovial
What is the function of the joint?
To connect the scapula to the clavicle
What are the articular surfaces of the joint?
Clavicle and Acromion
Describe the relation of the articular surfaces?
Flat facet at the lateral end of the clavicle with a flat facet on the anteromedial surface of the acromion
Is the clavicular surface convex or concave?
Convex
Is the acromion surface convex or concave?
Concave
What is the articular surfaces covered in?
Fibrocartilage
Describe the capsule?
Loose fibrous capsule
The capsule is thickest and strongest when it is reinforced by?
Trapezius
What lines the inner surface of the joint capsule?
Synovial membrane
What is the intra-articular structure involved in the joint?
Fibrocartilaginous Articular disc
What is the role of the articular disc?
To divide the joint cavity
What can the articular disc compensate for?
Small degree of incongruence between the articular surfaces
What are the ligaments involved in the joint?
Superior and Inferior acromioclavicular ligaments and coracoclavicular ligament
What are the two divisions of the coracoclavicular ligament?
Conoid and trapezoid
What is the stonger part of the coracoclavicular ligament?
Trapezoid
What limits anterior movement of the scapula?
Conoid
What limits posterior movement of the scapula?
Trapezoid
What does the coracoclavicular ligament do?
Prevents the acromion from sliding inferomedially under the lateral end of the clavicle
What is involved in the stability of the joint?
Coracoclavicular ligament, trapezius and deltoid muscles and capsular thickenings
Protraction is limited by?
Trapezoid part of coracoclavicular ligament
Retraction is limited by?
Conoid part of coracoclavicular ligament
ROM for elevation and depression?
less than 15 degrees
Elevation is limited by?
Tension in both parts of the coracoclavicular ligament
