The Shoulder Joint

Question 1

What type of joint is the shouder joint?

Answer 1

Ball and socket

Question 2

What are the articulating surfaces of the joint covered in?

Answer 2

Hylaine cartilage

Question 3

What are the two clinically important bursa?

Answer 3

The subacromial, which is located inferiorly to the deltoid and the acromion and suerpoirly to the supraspinatus bursa. There is also the subscapular, which is located between the subscapularis tendon and the scapula

Question 4

What are the three groups of ligaments important in stabilising the joint?

Answer 4

The glenohumeral ligament, the coracohumeral ligament, and the transverse humeral ligament.

Question 5

What forms the blood supply to the shoulder joint?

Answer 5

Via the anterior and posterior circumflex humeral ateries, and the suprascapular artery.

Question 6

What is the nervous supply of the shoulder joint?

Answer 6

Axillary, suprascapular and the lateral pectoral nerves which are from the C5 and C6 roots and therefore would be affected by ERbs palsy.

Question 7

What are the three factors that contribute to the stability of the joint?

Answer 7

The type of joint, as it is a ball and socket joint, the bony surface due to the shallow cavity and the large humeral head, and the laxity of the joint capulse.

Question 8

What are the factors that contibrute to the stability of the shoulder joint?

Answer 8

The rotator cuff muscles, which effectively pull the humerus into the glenoid cavity, and the glenoid labrum, and the ligaments

Question 9

Which is the most common direction in which the shoulder joint dislocates and why?

Answer 9

Anterior dislocations are the most common, as it allows the joint to tear through the weakest part of the joint capulse.

Question 10

What are the potential complications of dislocation of the humeral head?

Answer 10

The axillary nerve may be damaged, as it runs in close proximity to the humeral head, and the can also be stretching of the radial nerve, and tearing through the capsule can cause increased risk of future dislocation

Question 11

What is rotator cuff tendonitis and where it is commonly found?

Answer 11

This is generally caused by inflammation of the muscle tendons, and this is generally found due to friction between the subacromial bursa and the supraspinatus tendon.