Applied Anatomy of UL - The shoulder Flashcards
ED
52 yr. old male
FOOSH
Pain left shoulder
No PMH
Restricted movement
Likely diagnosis ?
Anterior dislocation of Glenohumeral Joint.
What type of Glenohumeral Joint dislocation is more common?
1- Anterior
2-Posterior
An anterior dislocation accounts for 97% of recurrent or first time dislocations. It is the most common dislocation and is caused by the arm being positioned in an excessive amount of abduction and external rotation.
What is this ?
Anterior dislocation of glenohumeral joint
How common is a posterior dislocation of the glenohumeral joint ?
Why is it this %?
How does it happen ?
What two conditions would you be more likely to see a posterior glenohumeral doslocation ?
WHY HAVE YOU GOT TO BE CAREFULL WITH POSTERIOR DISLOCATIONS ?
3% of glenohumeral joint are dislocation.
Every muscle in the shoulder girdle stimulated (tug of war, and shoulder dislocates posteriorly) making it unlikely.
It is caused by an external blow to the front of the shoulder. There is an indirect force applied to the humerus that combines flexion, adduction, and internal rotation.
Seizure and electrocution
THE X-RAYS CAN LOOK NORMAL.
What nerve should you be worried about with a shoulder dislocation ?
Axillary nerve injury
The axillary nerve wraps around the surgical neck of the humerus and supplies the teres minor and deltoid muscles as well as the skin overlying the lateral shoulder (known as the ‘badge area’).
Humeral head dislocation can damage the axillary nerve.
It is important to realise that the motor branch can be injured and the sensation left still intact.
What is the main source of stability for the shoulder joint ?
The glenohumeral ligaments
What are the glenogumeral ligaments and what do the do ?
- Glenohumeral ligaments(superior, middle and inferior)
- The joint capsule is formed by this group of ligaments connecting the humerus to the glenoid fossa. They are the main source of stability for the shoulder, holding it in place and preventing it from dislocating anteriorly. They act to stabilise the anterior aspect of the joint.
The rim of the glenoid fossa is called what ?
What does it do ?
Glenoid labrum–a fibrocartilaginous ridge surrounding the glenoid cavity. It deepens the cavity and creates a seal with the head of humerus, reducing the risk of dislocation.
Where are the Bursa located within the shoulder ?
- Subacromial - Reducing friction beneath the deltoid.
- Subscapular - Located between the subscapularis tendon and the scapula. It reduces wear and tear on the tendon during movement at the shoulder joint
What are “Bursa”
Synovial fluid filled sacs that act as a cushion
Bursa facilitate the sliding of muscles and ligaments over the capsule during movement of the joint
What is Subacromial bursitis ?
Subacromial bursitis (i.e. inflammation of the bursa) can be a cause of shoulder pain.
What is the medical term for frozen shoulder ?
Adhesive Capsulitis
What is the pathology of frozen shoulder (aka adhesive capsulitis?)
How does it present ?
Due to inflammation of the glenohumeral capsule
Pain and stiffness – especially at night
Can occur:
-Spontaneously
-Following rotator cuff injury
-Conditions causing immobility (CVA/plaster)
What is damaged in a shoulder dislocation that increases the risk of reacurrence ?
This results in damage to structures (labrum) providing joint stability and so increases the risk of recurrence
If the axillary nerve is injured due to shoulder dislocation
what motor functions will be affected ?
Which will there be a loss of sensation ?
Thedeltoid and teres minor muscles will be affected, rendering the patient unable to abduct the affected limb.
The upper lateral cutaneous nerve of arm will be affected, resulting in loss of sensation over the inferior deltoid (‘regimental badge area’).
Dislocation is associated with axillary nerve injury – impair deltoid and sensation over the “badge” area
