Upper Brachial Plexus Injuries and Rotator Cuff Problems

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Questions and Answers

Which of the following nerves and arteries are most vulnerable during shoulder dislocation and intramuscular injection?

Radial nerves and ulnar artery

Axillary nerves and brachial artery

Axillary nerves and circumflex artery (correct)

Median nerves and radial artery

What is the primary cause of painful arc/impingement syndrome in rotator cuff problems?

Overuse of the shoulder joint

Abduction of the arm between 70-120 degrees (correct)

Degenerative changes in tendons

Avulsion of the supraspinatus tendon

What is the direction of the humeral head in an anterior dislocation of the shoulder?

Anteriorly (correct)

Superiorly

Inferiorly

Posteriorly

Which of the following structures provides stability to the shoulder joint superiorly?

Coraco humeral ligament Signup and view all the answers

What is the nerve most likely to be injured during an anterior dislocation of the shoulder?

Axillary nerve Signup and view all the answers

Which of the following muscles is NOT involved in the development of a frozen shoulder?

Pectoralis major Signup and view all the answers

What is the most common direction of dislocation in the glenohumeral joint?

Inferior direction Signup and view all the answers

What is the primary cause of pain in a frozen shoulder when elevating the arm?

Strain on the acromioclavicular joint Signup and view all the answers

What is the result of tendons rubbing under the coraco acromial arch?

All of the above Signup and view all the answers

Which of the following conditions is most likely to cause a recurrent dislocation of the shoulder?

Adhesive fibrosis and scarring of the joint capsule Signup and view all the answers

What is the primary reason for the instability of the glenohumeral joint?

The unequal size of the articular surfaces of the scapula and humerus Signup and view all the answers

What is the function of the subscapular bursa in the shoulder joint?

To reduce friction between the tendon of the subscapularis and the scapula Signup and view all the answers

Which of the following structures is NOT directly involved in providing stability to the glenohumeral joint?

The tendon of the subscapularis Signup and view all the answers

What is the significance of the small opening in the capsule of the glenohumeral joint?

It enables the communication of the synovial membrane with the subscapular bursa Signup and view all the answers

What is the effect of the capsule's laxity on the glenohumeral joint?

It allows for a wide range of movement in many planes Signup and view all the answers

Study Notes

Brachial Plexus and Shoulder Movement

The brachial plexus roots C5 and C6 affect shoulder movement.
Upper brachial plexus injuries affect shoulder movement.

Neurovascular Relations and Clinical Applications

Axillary nerves and circumflex artery are vulnerable during intramuscular injections and shoulder dislocation.
Rotator cuff problems:
- Tendons rubbing under the coracoid acromial arch causes irritation and inflammation.
- Leads to subacromial bursitis, supraspinatus tendonitis, rotator cuff injury, and degeneration or rupture of tendons.

Rotator Cuff Problems

Causes of rotator cuff injuries:
- Overuse (e.g., sports, overhead use of arms)
- Degenerative changes in tendons (in older people)
- Avascularity of the supraspinatus tendon
- Slight differences in anatomy (making impingement more likely)
Rotator cuff problems result in painful arc/impingement syndrome (pain between 70-120 degrees of abduction).

Stability of the Shoulder Joint

Provided by:
- Tendons of the rotator cuff (anteriorly, posteriorly, and superiorly)
- Glenohumeral intracapsular ligaments (anteriorly and inferiorly)
- Coraco humeral ligament (superiorly)
- Coraco acromial arch (superiorly)
- Deepening of the glenoid cavity by the glenoid labrum
- Splinting effect of the long head of the biceps and triceps

Dislocation of the Glenohumeral Joint

The inferior aspect of the glenohumeral joint is the least protected.
Dislocation in the inferior direction is common, but clinically defined as an anterior dislocation.
The capsule and rotator cuff tendons may tear, leading to recurrent dislocation if they heal poorly.

Axillary Nerve Injury

Injured during dislocation due to its close relation to the inferior part of the joint capsule.
Indicated by:
- Paralysis of the deltoid muscle with loss of abduction
- Loss of sensation in a small area of the skin over the central part of the deltoid

Frozen Shoulder

Adhesive fibrosis and scarring between:
- The inflamed capsule
- Rotator cuff
- Subacromial bursa
- Deltoid
Difficulty in abducting the arm and lack of movement of the glenohumeral joint causes strain on the acromioclavicular joint, resulting in pain when elevating the shoulder.

The Shoulder Joint

Formed between the articular surfaces of the glenoid cavity of the scapula and the head of the humerus.
A ball and socket synovial joint allowing a wide range of movements in multiple planes.
Joint stability is affected by bone conformation and range of movement.

Glenohumeral Joint

Lined by synovium and enclosed by a fibrous capsule.
Glenoid cavity is deepened by a rim of fibrocartilage (the glenoid labrum).
Stability is provided by a capsule, various ligaments, and the rotator cuff muscles.
Capsule is attached to the glenoid labrum, scapula, and the anatomical head of the humerus.

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Description

This quiz covers the effects of upper brachial plexus injuries on shoulder movement, neurovascular relations, and clinical applications. It also explores rotator cuff problems and tendons inflammation.