9.05 Shoulder dislocation
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agk's Library of Common Simple Emergencies

Presentation
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The patient was holding his shoulder abducted 
horizontally to the side when a blow knocked 
the humeral head anteriorly. He arrives holding 
the shoulder abducted ten degrees from his 
side, unable to move it without increasing the 
pain. The delto-pectoral groove is now a bulge 
(caused by the dislocated head of the humerus) 
and the acromion is prominent laterally, with a 
depression below (where the head of the humerus 
sits on the undislocated shoulder).

What to to:
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- Provide analgesia. Ketorolac (Toradol) 60mg 
    im or 30mg iv is good, but you may need 
    intravenous narcotics. To abolish muscle 
    spasm and provide conscious sedation for a 
    difficult reduction, but have the patient 
    awake enough to go home in an hour, one 
    recommended regimen is intravenous 
    midazolam (Versed) 5mg and fentanyl 
    (Sublimaze) 0.1mg, given ten minutes before 
    the procedure, with continuous pulse 
    oximetry, iv fluids running, and the 
    physician by the bedside with bag-valve- 
    mask and endotracheal intubation kit ready. 
    Many shoulders, however, can be reduced 
    without conscious sedation.
- When analgesia is required, another alternat- 
    ive is to use intra-articular lidocaine. 
    After preparing the skin with povidone- 
    iodine, using a 1.5 inch 20 gauge needle, 
    inject 20 mL of 1% lidocaine 2 cm inferior- 
    ly and directly lateral to the acromion, in 
    the lateral sulcus left by the absent 
    humeral head.
- If available, obtain a pre-reduction x-ray to 
    rule out fractures or unreduceable 
    injuries. This image may be deferred and 
    speed treatment and relief if the injury 
    was recurrent and relatively atraumatic.
- Test and record the sensation over the 
    deltoid to establish if there is an injury 
    of the axillary nerve (rare) and confirm 
    the circulation, sensation, and movement in 
    the elbow, wrist and hand.
- Gain the patient's confidence by holding his 
    arm securely, asking him to relax, telling 
    him that you will not do anything suddenly 
    and that if any pain occurs you will stop. 
    Then in a very calm and gentle manner ask 
    him to let his muscles go loose so his 
    shoulder can stretch out.
- With the elbow flexed at 90 degrees, apply 
    steady traction at the distal humerus. Pull 
    inferiorly and at the same time externally 
    rotate the forearm very, very slowly. If 
    the patient complains of pain, stop 
    rotating, allow him to relax and let the 
    shoulder muscles stretch while you continue 
    to maintain traction along the humerus. 
    Resume external rotation when he is 
    comfortable again. Using this method, full 
    external rotation alone will reduce most 
    anterior shoulder dislocations.
- If you do not feel or see the shoulder joint 
    reduce, then, while maintaining traction 
    and external rotation, slowly and gently 
    adduct the humerus until it is against the 
    chest wall and then slowly internally 
    rotate the forearm against the anterior 
    chest. The vase majority of shoulder 
    dislocations can be reduced comfortably 
    this way, often without the use of any 
    analgesics.
- An alternative technique when you can palpate 
    the lateral border of the scapula is 
    reduction by scapular manipulation. With 
    the patient sitting up, place the uninjured 
    shoulder firmly against an immovable 
    support such as a wall or the raised head 
    of the stretcher. Have an assistant face 
    the patient and gently lift the 
    outstretched wrist of the affected arm 
    until it is horizontal. The assistant then 
    places the palm of his free hand against 
    the mid-clavicular area of the injured 
    shoulder as counterbalance, and then gently 
    put firmly pulls the patients arm towards 
    him. At the same time manipulate the 
    scapula by adducting the inferior tip using 
    thumb pressure, while stabilizing the 
    superior aspect with your upper hand.
- When the patient is comfortable and range of 
    motion has been restored, secure the 
    reduction in a sling and a swath around the 
    arm and chest. Obtain post-reduction x-
    rays, and discharge the patient once he is 
    alert, with a prescription of analgesics as 
    needed and an appointment for orthopedic 
    follow up in a week (sooner if any 
    problem).

What not to do:
---------------

- Do not use the forearm as a lever to fracture 
    the neck of the humerus.
- Do not redislocate the shoulder by repeating 
    the motions of the mechanism of injury.

Discussion
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Your strategy is to relocate the shoulder with 
minimal damage to the joint capsule and 
anterior labrum of the glenoid fossa, hoping 
the patient does not become a chronic 
dislocator with an unstable shoulder. Chronic 
dislocators are easier to reduce, and come less 
often to the ED, because they learn how to 
relocate their own shoulders.

Posterior dislocations are caused by internal 
rotation of the shoulder, as during a seizure, 
and are more subtle to diagnose. Subglenoid 
dislocation or luxatio erecta is rare and 
unmistakable, with the arm raised and abducted.

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