Shoulder dislocation Flashcards
How are they classified?
In relation to where the humeral head lies in relation to the glenoid fossa
- anterior and/or anterior inferior
- posterior
- inferior
Which is the most common type?
Anterior / anterior inferior = 95%
Posterior = 4%
Inferior = 1%
Superior displacement is prevented by…
Coraco-acromial arch
What is an anterior dislocation usually caused by?
Excessive extension and lateral rotation
Why is an anterior inferior dislocation most common?
The joint capsule is weakest here
What are Hill-Sachs lesions?
Impaction fracture of posterolateral humeral head against anteroinferior glenoid
What are Bankart lesions?
Detachment of anterior-inferior labrum with or without avulsion fracture
Which nerve runs in close proximity to joint?
Axillary - can be damaged in dislocation or with attempted reduction
What does injury to axillary nerve cause?
Paralysis of deltoid
Loss of sensation over regimental badge area
What typically causes a posterior dislocation?
Seizure or electrocution but can occur through trauma - direct blow to anterior shoulder
Which is the most commonly missed dislocation?
Posterior
How does a patient with a dislocated shoulder present?
Painful shoulder
Reduced mobility
Feeling of instability
What is often found on examination?
Asymmetry with contralateral side
Reduced shoulder contours - flattened deltoid
Anterior bulge - head of humerus
What associated injuries can occur?
Bony:
- Bony Bankart
- Hill- Sachs
- Fracture of greater tuberosity or head of humerus
Rotator cuff injuries
Glenohumeral ligament avulsion
Soft Bankart lesion
What investigations are required?
Trauma shoulder series - AP, Y scapular, axial
If labral or rotator cuff injury suspected: MRI
What sign suggests posterior dislocation?
Light bulb sign - fixed internal rotation
What view is useful for distinguishing anterior and posterior dislocations?
Y view
How is it managed?
A to E trauma assessment
Appropriate analgesia
Principle = reduction, immobilisation, rehabilitation
Attempt closed reduction first, may require manipulation under anaesthesia
Assess neurovascular status pre and post reduction
What sling should be used once reduced?
Broad arm sling
How long should it be immobilised for?
2 weeks
After immobilisation, what support should be offered?
Physiotherapy
