Shoulder Dislocations

Question 1

Most common dislocation

Answer 1

Shoulder dislocations and accounts for half of major joint dislocations presenting to ED

If not managed properly it can lead to chronic joint instability and chronic pain.

Question 2

Most common type of shoulder dislocation

Answer 2

Anteroinferior (most commonly termed as anterior) 95% of cases

Posterior and inferior dislocations make up the remainder

Question 3

Mechanism of anterior dislocation

Answer 3

Force applied to an extended, abducted and externally rotated humerus

Question 4

Mechanism of posterior dislocation

Answer 4

Seizures or electrocution or trauma

Direct blow to the anterior shoulder or force through a flexed adducted arm.

Posterior dislocations are often missed because x-ray findings can be subtle.

Question 5

Clinical features

Answer 5

Acutely painful shoulder

Acutely reduced mobility

Feeling of instability

Question 6

Examination findings of dislocation

Answer 6

Asymmetry with contralateral side

Loss of shoulder contours/squaring of shoulder (e.g. flattened deltoid)

Anterior bulge from the head of the humerus

Question 7

Other that shoulder examination what is important to do as well?

Answer 7

Neurovascular status since axillary and suprascapular nerves might be compromised. (This should be done both pre- and post-reduction)

Also examine joint above and below.

Question 8

Associated injuries with shoulder dislocation.

Answer 8

Bony Bankart lesions (fracture of anterior inferior glenoid bone/fossa)

Hill-Sachs defects (impaction injury to the chondral surface of the posterior and superior portions of the humeral head)

Greater tuberosity and surgical neck of humerus fractures can also occur.

Soft Bankart lesions - avulsions of the anterior labrum and inferior glenohumeral ligament

Glenohumeral ligament avulsion

Rotator cuff injuries

Question 9

Investigations of shoulder dislocation

Answer 9

X-ray should be done.

A trauma shoulder series is required with anterior posterior, Y-scapular + axial views

MRI might be done if labral or rotator cuff injuries are suspected.

Question 10

Best X-ray view for anterior dislocations

Answer 10

AP film

Y-scapular can also show anterior dislocation

Question 11

Findings on X-ray of anterior disocation.

Answer 11

Humeral head is visibly out of glenoid fossa

Also check for concurrent bony injuries

Question 12

Best X-ray view for posterior dislocation.

Answer 12

Y-scapular view because it can differentiate between anterior and posterior dislocation

Question 13

X-ray findings of posterior dislocation.

Answer 13

Light bulb sign as the humerus is fixed in internal rotation

Question 14

Management of dislocation

Answer 14

A-E trauma assessment

Provide appropriate analgesia

Reduction, immobilisation and rehab.
Closed reduction (like Hippocratic method) should be performed by a trained specialist.

Assess neurovascular status pre and post-reduction.

Question 15

Management of shoulder dislocation once reduced.

Answer 15

Broad-arm sling usually for 2 weeks. Might be longer if posterior dislocation.

Physiotherapy to restore range of movement, functionality and to strengthen rotator cuff and pericapsular musculature.

Question 16

When might further surgical interventions be done?

Answer 16

Future surgical treatment if shoulder pain, joint instability, large Hill-Sachs defects or large Bony Bankart lesions

Question 17

Prognosis of shoulder dislocation.

Answer 17

Chronic pain, limited mobility, stiffness and recurrence are all possible.

Adhesive capsulitis, nerve damage, rotator cuff injury.

Degenerative joint disease.