Lecture - The Shoulder Joint Flashcards
Which bones articulate to form the shoulder joint?
The glenoid fossa of the scapula and the head of the humerus
What is the problem with the glenoid cavity, and how is this reduced?
Shallow socket - overcome by the glenoid labrum, a fibrocartilage rim around the cavity, which deepens it slightly.
What makes the shoulder joint unstable?
Shallow
Lax capsule
Multiplanar movements
What makes the shoulder joint more stable?
Rotator cuff muscles
Capsule
Ligaments
Glenoid labrum
What is a joint capsule?
A fibrous sheath which encloses joint structures
Where does the shoulder joint capsule attach?
Stretches from the glenoid labrum to the anatomical neck of the humerus, from which it bridges the intertubercular groove and dips down to the surgical neck.
Where is the synovial membrane located and what is its function?
Lines the inner surface of the joint capsule.
Produces synovial fluid to act as lubricant
What is the function of synovial bursae?
Act as a cushion/reduce friction
Which 2 bursae in the shoulder joint are clinically important?
Subacromial
Subscapular
Where is the subacromial bursa located?
Inferior to the deltoid and and the acromion
Superior to the joint capsule and supraspinatus tendon
Through which degrees are pain felt in subacromial bursitis?
60 - 120*
Where is the subscapular bursa located?
Between the subscapularis tendon and the scapula
What is the function of the subacromial bursa?
What about the subscapular bursa?
Subacromial - facilitates movement of deltoid and supraspinatus
Subscapular - reduces wear and tear of subscapularis tendon
Which 4 tendons stabilise the glenohumeral joint?
Which are thickenings of the capsule, and which are separate?
Coracoacromial ligament - separate
Glenohumeral ligaments - capsule
Coracoacromial ligament - capsule
Transverse humeral ligaments - capsule
Where does the glenohumeral ligament stretch between?
What is its function?
- Glenoid labrum and humerus
- Stabilises anterior aspect of joint
