• Assess for accompanying trauma.
• Assess neurovascular status.

• 97% of shoulder dislocations are anteriorly located.
• >90% of anterior shoulder dislocations are reducible in the ED.
• Prior history of shoulder dislocation predisposes patients to repeat dislocations of the same joint.
• Delays in shoulder reduction can decrease reduction success rates.
• Pain management promotes muscle relaxation which can improve success rates and decrease reduction times.
• Slow, gradual reduction maneuvers are important in minimizing axillary nerve complications.

Clinical Examination

• Most shoulder dislocations can be diagnosed clinically.
• Key examination findings suggestive of each type of dislocation include:
  • Anterior Dislocation (97% of cases)
    • Mechanism of injury involving excessive external rotation while abducted.
    • Arm held in slight abduction and external rotation.
    • Loss of normal round appearance of deltoid.
    • Prominent acromion laterally and/or posteriorly: step-off deformity.
    • Humeral head palpable anteriorly.
  • Posterior Dislocation (2% of cases)
    • Mechanism of injury involves electrical shock, tonic-clonic seizure, or trauma.
    • Arm held in adduction and internal rotation.
    • Often missed due to low clinical suspicion and limited radiographic signs — maintain a high index of suspicion in patients with unexplained shoulder immobility.
  • Inferior Dislocation (< 1% of cases, Luxatio Erecta)
    • Mechanism of injury involving forceful hyperabduction of arm.
    • Classic presentation with elbow flexed and arm abducted above patient’s head.
• Radiography
  • Pre-reduction radiographs are not required in low-risk scenarios where fractures are not suspected.
  • The Quebec-Fresno rules have demonstrated 100% sensitivity in identifying situations that warrant pre-reduction radiographs:
    • If an atraumatic, recurrent episode Þ No radiographs warranted.
    • If age > 35 or the mechanism of injury involves MVA, assault, sports or a fall > 10ft Þ Radiographs warranted.
  • Post-reduction radiographs confirm successful reduction and rule out any injury due to the reduction procedure itself.
  • Standard shoulder radiographs:
    • The axillary view is particularly helpful in diagnosing posterior dislocations.
    • If no axillary view is available, look for the following signs of a posterior dislocation on AP view:
      • Lightbulb Sign ⇒ Internal rotation of humeral head gives it a rounded appearance (https://radiopaedia.org/articles/light-bulb-sign-posterior-shoulder-dislocation.)
      • Rim Sign ⇒ Widened glenohumeral joint space (http://www.gentili.net/signs/images/400/shoulderpostdisloc.JPG)
      • Trough Sign ⇒ Dense vertical line in medial humeral head due to impression fracture (https://radiopaedia.org/articles/trough-line-sign)
      • Absent Half-Moon Sign ⇒ Glenoid fossa appears empty due to displaced humerus (https://radiopaedia.org/articles/loss-of-normal-half-moon-overlap-sign-shoulder)
• Neurovascular Status
  • Axillary nerve compromise may initially present in >40% of shoulder dislocations.
  • Neurovascular status should be assessed in all shoulder dislocations.
    • Motor
      • Axillary Nerve ⇒ Movement (including twitch) of deltoid muscle.
      • Median, radial, ulnar nerves.
    • Sensory
      • Axillary Nerve ⇒ Lateral deltoid region (“military patch”).
      • Median, radial, ulnar nerves.
    • Vascular
      • Ulnar and radial pulse.

There are 3 main steps to reducing/managing shoulder dislocations:

1. Rule out contraindications to reduction.
2. Shoulder reduction (with or without analgesia).
3. Post reduction management.

• Contraindications to Immediate Reduction
  • If any of the following are noted, urgent orthopedic and/or vascular consult is required but reduction is often still necessary ASAP and with procedural sedation to minimize further trauma:
    • Multipart fractures.
    • Fractures of surgical neck (risk of avascular necrosis).
    • Open fractures (unless neurovascular deficits present).
    • Delayed reductions (> 6 weeks) in posterior dislocations.
    • Signs of vascular injury in inferior dislocations.
• Shoulder Reduction
  • Analgesia / Sedation
    • Recent and/or recurrent anterior dislocations are often readily reducible without the need for analgesia.
    • Anesthesia/sedation is recommended in delayed reductions (> 3 weeks) or posterior/inferior dislocations.
    • Intra-articular anesthesia and nerve blocks are preferred over procedural sedation, when possible.
  • Anterior Dislocation
    • All reduction techniques benefit from patient relaxation and constant traction of the limb.
    • Research suggests no significant difference in efficacy between reduction techniques.
    • Providers should be familiar with several reduction techniques in the case that initial attempts fail.
    • The Mohr Method was developed locally by Dr. Bruce Mohr, and involves a gradual, seamless progression through the following reduction techniques:
      • Video | https://www.youtube.com/watch?v=tSf5ilBr4yo&t=166s
      • Images of Each Technique | https://www.sciencedirect.com/science/article/pii/B9780323763004000175#f5117

Cunningham

With a seated patient, apply gentle axial traction to the affected arm. The elbow is flexed approximately 90º and the arm is fully adducted. Encourage patient to sit up straight, retract scapulae and push chest out. Massage patient’s trapezius, deltoid and biceps muscles (3 seconds each, in that order).Patients often note improvement in symptoms within 1-2 minutes if successful.

External Rotation

In the same position with traction maintained, slowly externally rotate the arm. Do not rush. Ensure the arm remains fully adducted. The shoulder should reduce by 45-60º of external rotation.

Forward Flexion

Lower the head of the exam table so that the patient is supine. With the arm externally rotated about 30º, grab the patient’s hand/wrist. Extend the elbow so that the arm is straight. Transfer traction from the patients elbow to their hand/wrist. Supinate the arm. While maintaining traction, slowly elevate the patient’s arm forward. The shoulder should reduce by 45º of forward elevation.

SPASO

Continue elevating the arm slowly to 90º (supine patient’s arm pointing straight up). Ensure the arm is supinated and continue to apply gentle traction. An assistant can stabilize the clavicle, so the patient is not lifted off of the exam table.

FARES

With the patient supine, apply gentle traction with the arm abducted 45º. Oscillate the arm anterior-posteriorly. (~5cm each direction, 1-2 cycles / second). While oscillating, slowly abduct arm to 90º. If shoulder remains unreduced, externally rotate arm and continue abduction. The shoulder should reduce by 120º of abduction.

Modified Milch

Internally rotate the arm to normal and return to 90º abduction. Flex the elbow 90º and internally rotate the arm so that fingers are pointed anteriorly. Externally rotate the arm.

Scapular Manipulation

Position the patient prone with their affected arm hanging off the side of the table. An assistant applies gentle downwards traction to the arm. Alternatively, the patient can hold a weight. With one hand, stabilize the superior angle of the scapula. With both thumbs, apply medial and dorsal pressure to the inferior tip of the scapula. The shoulder should reduce within 1-2 minutes.

Posterior Dislocation

• Due to frequently being diagnosed late, posterior shoulder dislocations warrant orthopedic consultation.
• Analgesia/sedation is used routinely for posterior reductions.

Traction-Countertraction

With the patient supine, an assistant wraps a sheet from the unaffected side across the patient’s chest, under the axilla on the affected side, and returns around their back. The assistant ties this sheet around their hips and applies gentle traction. Simultaneously, slightly abduct their affected arm and apply firm, gradual traction. A second assistant may apply gentle pressure to the humeral head anteriorly and laterally.

Video: https://www.youtube.com/watch?v=KRCqVekNEKc&t=110s

Inferior Dislocation

• Due to association with axillary nerve injury, inferior shoulder dislocations warrant orthopedic consultation.
• Analgesia/sedation is used routinely for inferior reductions.

Traction-Countertraction

With the patient supine, an assistant wraps a sheet from the unaffected side across the patient’s chest, over the trapezius on the affected side, and returns around their back. The assistant ties this sheet around their hips and applies gentle traction. Simultaneously, apply upward, axial traction to the affected arm. Use other hand to translate humeral head anteriorly and laterally, over the glenoid rim.

Video: https://www.youtube.com/watch?v=k_ORI51luFI

Video: https://www.youtube.com/watch?v=C8Irt39KBgk

Post-Reduction Management

• Reassess neurovascular status in all patients post-reduction.

Immobilization

• Anterior Dislocations
  • Traditional immobilization via adduction and internal rotation in an immobilizer or sling.
  • Limited evidence suggests a decreased recurrence rate of dislocations in patients immobilized with external vs internal rotation (21.5% vs 34.9%).
  • Patients may expect increased discomfort with external rotation vs internal rotation immobilization.
  • No evidence-based consensus exists on optimal duration of immobilization.
  • A meta-analysis demonstrated that immobilization >1 week failed to improve recurrence rates.
•  Posterior / Inferior Dislocations
  • Shoulder immobilizer use is required (20º and slight abduction for posterior, 0º and adducted for inferior).
  • No evidence-based consensus exists on optimal duration of immobilization.
  • Some sources suggest immobilization for 2-3 weeks, but should be at the discretion of the consulting orthopedic surgeon.

Rehabilitation

• Physiotherapy referral for personalized rehabilitation is advised, if available.
• No evidence-based consensus exists on optimal rehabilitation program.
• In the absence of physiotherapist referral, patients can be given the following general guidelines based on expert opinion:
  • Avoid shoulder movement during immobilization period (particularly external rotation and abduction in anterior dislocations).
  • Following immobilization period, begin passive ROM, gentle isometrics and closed kinetic chain exercises for 2-3 weeks — restrict early movement to scapular plane and <90º abduction.
  • After 4-6 weeks, full ROM and strengthening exercises (including scapular and rotator cuff muscles) may be implemented — detailed exercises may be referenced here: https://openorthopaedicsjournal.com/VOLUME/11/PAGE/957/

Referral

• Arrange orthopedic follow-up for all patients with posterior/inferior dislocations.
• Consider referring patients with anterior dislocations who may benefit from shoulder stabilization surgery to prevent repeat dislocations.
• A 2023 meta-analysis suggests patients who undergo surgical treatment for first-time anterior dislocations have a lower rate of future instability (40% vs 6%).
• RCTs show young, active patients (age 15-39) stand to benefit the most from surgical management.
• In traumatic anterior dislocations, the average risk of recurrence following non-surgical management can reach nearly 40%, with the highest risk in men (OR=3.18) and younger patients (OR=13.48).
• Surgical benefit must be considered against the cost, so referral criteria remains largely provider dependent — many clinicians consider referral after 2 atraumatic anterior dislocations.

• Open fracture.
• Severe accompanying trauma.
• Complications due to sedation.

• If urgent surgery required and not available in-house.
• Patients should be immobilized in a sling and given analgesia.

• Open fractures.
• Complex fractures.
• Surgical neck or humeral head fracture.
• Unsuccessful reduction.
• Posterior/inferior dislocations.
• Signs of vascular injury (orthopedic and vascular consult).

• Patient discharged if stable, shoulder is reduced and no neurovascular deficits are present.
• Post-reduction management (see above) should be discussed.
• If a sedative was given, no driving or machinery operation for 24 hours.

1. Reduction techniques: https://www.sciencedirect.com/science/article/pii/B9780323763004000175#f5117

   
   

2. Detailed physiotherapy program: https://openorthopaedicsjournal.com/VOLUME/11/PAGE/957/

   
   

1. Gottlieb M & Alerhand S. Prereduction Radiographs are not Routinely Needed for Anterior Shoulder Dislocations. Ann Emerg Med. 2020;76(2):132-133. Available from: https://www.sciencedirect.com/science/article/abs/pii/S0196064420301335

   
   

2. Émond M, Gariepy C, Boucher V, Hendey GW. Selective Prereduction Radiography in Anterior Shoulder Dislocation: The Fresno-Quebec Rule. J Emerg Med. 2018;55(2):218-255. Available from: https://www.sciencedirect.com/science/article/abs/pii/S0736467918304852

   
   

3. Dong H, Jenner EA, Theivendran K. Closed reduction techniques for acute anterior shoulder dislocation: a systematic review and meta-analysis. Eur J Trauma Emerg Surg. 2021;47(2):407-421. Available from: https://link.springer.com/article/10.1007/s00068-020-01427-9

   
   

4. Belk JW, Wharton BR, Houck DA, Bravman JT, Kraeutler MJ, Meyer B et al. Shoulder Stabilization Versus Immobilization for First-Time Anterior Shoulder Dislocation: A Systematic Review and Meta-analysis of Level 1 Randomized Controlled Trials. Am J Sports Med. 2023;51(6):1634-1643. Available from: https://journals.sagepub.com/doi/10.1177/03635465211065403

   
   

5. Shinagawa K, Sugawara Y, Hatta T, Yamamoto N, Tsuji I, Itoi E. Immobilization in External Rotation Reduces the Risk of Recurrence After Primary Anterior Shoulder Dislocation: A Meta-analysis. Orthop J Sports Med. 2020;8(6). Available from: https://journals.sagepub.com/doi/10.1177/2325967120925694