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
