Acromioclavicular Joint Flashcards
What are the articulating surfaces of the AC joint lined with?
Fibrocartilage
What is the articulating disc?
A wedge of fibrocartilage suspended from the upper part of the capsule, partially dividing the joint cavity
Where does the articular disc arise from?
The loose fibrous layer which encloses the joint- the joint capsule
How is the posterior aspect of the joint capsule reinforced?
By fibres from the trapezius muscle
What kind of joint is the AC joint?
A synovial joint
What are the ligaments present at the AC joint? (2/3)
Acromioclavicular
Conoid
Trapezoid
**conoid and trapezoid can be considered as one= coracoclavicular ligament
What is the acromioclavicular ligament?
Ligament running horizontally from the acromion to the lateral clavicle, coves the joint capsule, reinforcing it superior aspect
What is the conoid ligament?
Ligament running vertically from the coracoid process of the scapula to the conoid tubercle of the clavicle
What is the trapezoid ligament?
Ligament running from the coracoid process of the scapula to the trapezoid line of the clavicle
What does the coracoclavicular ligament (conoid + trapezoid ligaments ) do?
Effectively suspends the weight of the upper limb from the clavicle
Is the movement of the AC joint passive or active, why?
Passive, it is secondary to other movements because there are no muscles moving the joint directly
What are the two arterial blood supplies to the AC joint?
Suprascapular artery (arising from the subclavian artery at the thyrocervical trunk) Thoraco-acromial artery (arises from the axillary artery)
What nerves innervate the AC joint?
Suprascapular and lateral pectoral nerves (arising from brachial plexus)
What is another name for acromioclavicular joint dislocation?
Separated shoulder
What is an AC joint dislocation associated with?
Soft tissue damage at the joint
What happens if the coracoclavicular ligament is torn after an AC joint dislocation?
The weight of the upper limb is not supported and the shoulder moves inferiorly, meaning the clavicle is increasingly prominent
What are the treatments for an AC joint dislocation?
Can range from ice and rest to ligament reconstruction surgery
What type of synovial joint is the acromioclavicular joint?
Plane joint
How might acromioclavicular osteoarthritis be treated?
By taking out some of the clavicle
How might someone present with a acromioclavicular osteoarthritis?
High painful arc
Tender joint
