The shoulder

Question 1

What is the glenohumeral joint?

Answer 1

• Ball and socket joint

- Glenoid fossa and the humerus

Question 2

Why is the glenohumeral joint relatively unstable?

Answer 2

Humerus (ball) is larger than the glenoid fossa (socket)

Question 3

What factors contribute to the stability of the glenohumeral joint?

Answer 3

• Glenoid labrum
• Roatator cuff muscles
• Long head of the biceps
• Ligaments (intrinsic and extrinsic)

Question 4

What are the intrinsic glenohumeral joint ligaments?

Answer 4

• Glenohumeral = supports anteriorly (superior, middle and inferior)
• Corachohumeral = supports superiorly

Question 5

What are the extrinsic glenohumeral joint ligaments?

Answer 5

• Transverse humeral = connects tubercles and holds the tendon of the long head of biceps
• Coracoacromial = prevents superior displacement of the humeral head

Question 6

What type of bone is the scapula?

Answer 6

Irregular bone

Question 7

What are the articulations of the scapula?

Answer 7

• Glenohumeral joint

- Acromioclavicular joint

Question 8

What type of bone is the clavicle?

Answer 8

Long bone

Question 9

What is the medial end of the clavicle referred to and what curvature does it have?

Answer 9

Sternal end

-convex anteriorly

Question 10

What is the lateral end of the clavicle referred to and what curvature does it have?

Answer 10

Acromial end

-concave anteriorly

Question 11

Describe the acromioclavicular joint

Answer 11

• Plane type
• Synovial joint
• Acromial end of the clavicle and the acromion of scapula
• Lined with fibrocartilage rather than hyaline

Question 12

What are the ligaments of the acromioclavicular joint?

Answer 12

• Acromioclavicular ligament = acromion to lateral clavicle horizontally (intrinsic)
• Conoid ligament = coracoid to conoid tubercle of clavicle (extrinsic)
• Trapezoid ligament = coracoid process to trapezoid line of the clavicle (intrinsic)

Conoid and trapezoid is known as coracoclavicular ligament

Question 13

Describe the sternoclavicular joint

Answer 13

• Saddle type
• Synovial joint
• Clavicle and manubrium of the sternum
• Fibrocartilage lining than hyaline
• Very strong
• Mobile

Question 14

What neurovascular structures pass through quadrangular space?

Answer 14

• Axillary nerve

- Posterior circumflex humeral artery (and vein)

Question 15

What are the borders of the quadrangular space?

Answer 15

• Superior = teres minor
• Inferior = teres major
• Medial = long head of triceps brachii
• Lateral = surgical neck of humerus

Question 16

What are the 2 bursae around the shoulder joint?

Answer 16

• Subacromial = under acromion, separates supraspinatus tendon and coracoacromial ligament
• Subscapular = beneath tendon of subscapularis and neck of scapula