MSK 15 - Upper Limb-I

Question 1

Answer 1

Question 2

How can you tell which end of the clavicle is which?

Answer 2

The flat end is the acromial end and the quatdrangular end is the sternal end

Question 3

Answer 3

Question 4

Answer 4

Question 5

Answer 5

Question 6

Where do most fractures of the proximal humerus occur and what else can be injured with these fractures?

Answer 6

Question 7

Answer 7

Question 8

List all of the joints of the shoulder complex.

Answer 8

1. Sternoclavicular (sternum and clavicle)
2. Acromioclavicular (scapula and clavicle)
3. Glenohumeral (humerus and scapula)
4. Scapulothoracic (scapula and thorax)

Question 9

What are the synovial joints of the shoulder complex?

Answer 9

Sternoclavicular

Acromioclavicular

Glenohumeral

Question 10

What is impingement syndrome?

Answer 10

A clinical syndrome which occurs when the tendons of the rotator cuff muscles become irritated and inflamed as they pass through the subacromial space

Question 11

What type of movement does the sternoclavicular joint do?

Answer 11

Question 12

What ligaments form/reinforce the sternoclavicular joint?

Answer 12

1. Anterior sternoclavicular ligament (forms most of the joint)
2. Interclavicular ligament
3. Costoclavicular ligament

Question 13

Answer 13

Question 14

What type of movement does the acromioclavicular joint allow for and what ligaments reinforce this joint?

Answer 14

Question 15

Answer 15

Question 16

Answer 16

Question 17

What is the glenoid labrum and what is its primary purpose?

Answer 17

The glenoid labrum (glenoid ligament) is a fibrocartilaginous rim attached around the margin of the glenoid cavity in the shoulder blade. It serves to deepen and strengthen the glenohumeral joint

Question 18

Where does the synovial membrane of the glenohumeral joint attach?

Answer 18

To the margins of the articular suface

Question 19

Answer 19

Question 20

What ligaments serve to thicken the joint capsule of the glenohumeral joint?

Answer 20

The superior, middle, and inferior glenohumeral ligaments

The coracohumeral ligament

The transverse humeral ligament

Question 21

Answer 21

Question 22

Answer 22

Question 23

When a clavicle is broken, how are the fragments usually displaced and why?

Answer 23

Question 24

What are some injuries typically associated with a clavicle fracture?

Answer 24

Pneumothorax

Damage to subclavian vein and artery

Question 25

What are the varying degrees of shoulder separation injuries?

Answer 25

Question 26

List the muscles that act on the shoulder joint and what they do.

Answer 26

* Deltoid - abducts arm from 15-90 degrees * Pectoralis major - flexion, adduction and medial rotation of arm * Serratus anterior - rotates scapula upward for abduction of arm above 90 degrees * Trapezius - helps rotate scapula during abduction of arm \>90 degrees, elevation of scapula * Teres major - extension, adduction, medial rotation of the arm * Latissimus dorsi - extends, adducts and medially rotates arm * Supraspinatus - abduction of arm from 0-15 degrees * Infraspinatus - lateral rotation of arm * Subscapularis - medial rotation of arm * Teres minor - lateral rotator of arm

Question 27

List the muscles that act on the shoulder joint and the nerves that innervate them.

Answer 27

* Deltoid - axillary nerve * Pectoralis major - medial and lateral pectoral nerves * Serratus anterior - long thoracic nerve (C5-C7) * Trapezius - spinal accessory nerve * Teres major - lower subscapular nerve * Latissimus dorsi - thoracodorsal nerve * Supraspinatus - suprascapular nerve * Infraspinatus - suprascapular nerve * Subscapularis - upper and lower subscapular nerves * ​Teres minor - axillary nerve

Question 28

What is the mnemonic to remember the rotator cuff muscles?

Answer 28

SITSS S - Supraspinatus I - Infraspinatus T - Teres minor SS - subscapularis

Question 29

Answer 29

Question 30

Discuss the most common rotator cuff injury.

Answer 30

Question 31

What is Hilton's law?

Answer 31

Any nerve that provides motor innervation to the muscles acting on a joint will also carry sensation from the joint

Question 32

List the vessels that innervate and supply blood to the shoulder joint.

Answer 32

Innervation - posterior cord of the brachial plexus, terminal branches of the brachial plexus, suprascapular nerve, axillary nerve, and the lateral pectoral nerves Blood Supply - branches of the antreior and posterior circumflex humeral and suprascapular arteries

Question 33

Answer 33

Question 34

Why are many shoulder dislocations in the anterior-inferior direction?

Answer 34

Typically the subscapularis is the muscle of the rotator cuff that gives out first. Because of this most should dislocations occur toward that muscle which is anteriorly and inferiorly

Question 35

What neurovascular structures are often damaged in shoulder dislocation injuries? What sensory and motor deficits could this lead to?

Answer 35

Axiallary nerve and posterior humeral circumflex artery This could lead to a decreased ability to laterally rotate the arm (teres minor), abduct the arm from 15-90 degrees (deltoid), and could lead to a sensory deficit in the upper lateral part of the arm.