Shoulder Flashcards
(103 cards)
What structure surrounds the AC joint to provide stability?
A joint capsule.
What is the function of the conoid ligament?
Resists elevation and protraction of the clavicle.
Where does the conoid ligament run?
Vertically between the coracoid process and the clavicle.
What is the function of the trapezoid ligament?
Provides AC joint compression.
Where does the trapezoid ligament run?
In a superior and lateral direction between the coracoid process and the clavicle.
What happens to the clavicle during elevation?
Both costoclavicular ligaments develop tension, causing posterior rotation of the clavicle along its long axis.
What forces do the costoclavicular ligaments resist?
Upward rotation forces of the scapula.
What is the function of the acromioclavicular ligament?
Covers the joint capsule and reinforces its superior aspect.
(i.e. strengthens and supports the upper part of the joint capsule.)
Where does the acromioclavicular ligament run?
Horizontally from the acromion to the clavicle.
What surrounds the entire SC joint?
A joint capsule.
Why is the SC joint capsule considered weak?
It relies on ligaments for additional support.
Which ligaments provide anterior and posterior support to the SC joint?
Anterior and posterior sternoclavicular ligaments.
What is the function of the interclavicular ligament?
Provides restraint to inferior forces on the medial end of the clavicle.
Where does the interclavicular ligament span?
Between both medial ends of the clavicles.
What ligaments make up the costoclavicular ligament complex?
An anterior and posterior bundle.
Where does the costoclavicular ligament complex attach?
From the superior surface of the first rib to the undersurface of the clavicle.
What is the function of the costoclavicular ligament complex?
Limits excessive superior, anterior, or posterior movement of the medial end of the clavicle.
What type of joint is the SC joint?
A saddle-shaped joint.
Why is the SC joint considered inherently unstable?
Its bony structure provides minimal stability.
How many degrees of rotation and translation does the SC joint allow?
Three degrees.
What structure within the SC joint enhances stability?
An articular disk.
What is the function of the articular disk in the SC joint?
Provides stability and separates the joint into two compartments.
Despite its instability, why is the SC joint rarely dislocated?
It rarely dislocates due to the support of strong ligaments and surrounding structures.
Which ligament is considered the most important for SC joint stability?
The posterior sternoclavicular ligament.