Anterior shoulder dislocation

Background

Shoulder anatomy, anterior.
Shoulder anatomy, posterior.
  • Shoulder dislocations account for 50% of all major joint dislocations, 90-98% are anterior[1]
  • Majority of anterior shoulder dislocations are due to trauma
  • Important to rule out axillary nerve injury
    • Most common finding is 'military patch' (deltoid) anesthesia

Clinical Features

  • Pain
  • Arm maintained in abduction
  • Shoulder appears 'squared off' (loss of normal rounded appearance with stretching of the deltoid muscle)
  • Difficulty touching affected arm to contralateral shoulder due to pain

Chronic Anterior Dislocation

  • Risk of axillary artery rupture with reduction of chronic dislocation [2][3]
    • Patient with shoulder dislocated 3-4 weeks should be reduced only with orthopedic consultation, and likely in the operating theatre[4]

Differential Diagnosis

Shoulder and Upper Arm Diagnoses

Traumatic/Acute:

Nontraumatic/Chronic:

Refered pain & non-orthopedic causes:

Evaluation

Imaging

Anterior dislocation
Anterior dislocation of the right shoulder on Y-view X ray.
Anterior dislocation with fracture
  • Plain film X-ray of shoulder
    • At least 2 views
      • Axillary lateral or scapular "Y" view can help distinguish between anterior and posterior dislocation
    • Rule out associated fracture
  • May forego imaging if:
    • Age <40
    • Atraumatic mechanism
    • Multiple past dislocations
    • Clinically consistent with dislocation
  • Bedside ultrasound can be used to assess for both dislocation and successful reduction

Management

Traction-Countertraction
External Rotation (Kocher)
Stimson
Milch
  • Closed reduction (see techniques below)
    • Note: do not reduce chronic dislocations (>4 weeks) in the ED due to risk of arterial injury
      • Consult orthopedics for cautious attempt at closed reduction or open reduction
  • Procedural sedation often required
    • Consider intra-articular lidocaine (10-20mL) as alternative to procedural sedation[5]
  • After reduction, apply immobilizer with shoulder in adduction and internal rotation
  • Refer all first-time dislocations for outpatient orthopedic follow up
  • Recurrent dislocators who have not undergone repair benefit from outpatient orthopedic referral for consideration of rotator cuff repair (traumatic mechanism) or capsular plication (atraumatic)

Reduction Techniques

Techniques that generally do not require sedation

  • FARES (Fast, Reliable, and Safe) Method:
  1. Place the patient supine or prone
  2. Grasp the affected arm at the wrist
  3. Gently oscillate the arm anteriorly and posteriorly (up and down as the patient is supine)
  4. Apply gentle traction to the arm and slowly abduct
  5. Once abducted to 90 degrees, externally rotate
  6. Continue with ongoing traction and oscillation until reduction is achieved (generally with 120 degrees of abduction)
  1. Stand in front of the seated patient
  2. Hold the patient's affected arm adducted with the elbow flexed to 90 degrees
  3. Massage trapezius, deltoid and bicipital muscles
  4. Instruct the patient to move the shoulder superiorly and posteriorly to facilitate humeral head reduction (bring shoulder back and chest out) [6]
  1. Place the patient in a seated position on an examination table
  2. Instruct the patient to flex the knee ipsilateral to the affected shoulder
  3. Ask the patient to hold the wrist of the affected arm in the hand of the unaffected arm with both looped around the fully flexed knee
  4. Tie the affected and unaffected wrists together around the fully flexed knee
  5. Sit on the patient's foot to stabilize
  6. Keeping the elbows adducted, ask the patient to slowly lean head back and allow shoulder to roll forward
    • Neck extension creates traction on the injured shoulder, which allows it to reduce
  • Snowbird Technique
  1. Place patient in an upright sitting position
  2. Adduct the affected arm and flex the elbow to 90 degrees
  3. Create a loop of stockinette
  4. Hang the loop of stockinette over the flexed elbow
  5. Position an assistant behind the patient with arms under the axillae to provide countertraction
  6. Using your hands to maintain flexion of the elbow, place your foot in the loop of stockinette and apply downward pressure to create traction on the elbow

Techniques that typically require sedation

  1. Place patient supine seated on exam table
  2. Adduct affected arm and flex 90 degrees at the elbow
  3. Externally rotate the shoulder (70-85 degrees) until resistance is felt
  4. Lift arm anteriorly as far as possible
  5. Internally rotate shoulder, moving hand towards contralateral shoulder
  6. Humeral head should slip back into place
    • Note that a modified Kocher technique avoids abduction and internal rotation and reduces the dislocated shoulder through external rotation alone
  1. Place patient supine on exam table[10]
  2. Grasp the wrist of the affected arm
  3. Slowly abduct and externally rotate the arm until it is in the overhead position
  4. Using your free hand, manipulate the humeral head laterally and superiorly to achieve reduction
  • Scapular manipulation
  1. Position yourself behind the patient
  2. Stabilize the superior aspect of the shoulders with your fingers
  3. Placing your hands on the patient's back, push the inferior tip of the scapular medially and dorsally with your thumbs
  • Stimson
  1. Place patient prone on edge of table (affected shoulder closest to table edge)
    • Note that this is not an ideal technique as it requires a sedated patient to lay face-down, potentially leading to suffocation on the exam table
  2. Allow hand to drop off table perpendicular to body
  3. Attach 5 kg weight to arm
  4. Maintain position for 20 - 30 minutes as needed
  5. Provide additional scapular manipulation or gentle external and internal rotation to promote reduction
  • Traction-Countertraction
  1. Place patient in a supine position with a sheet wrapped around the torso and under the axilla of the affected arm
  2. While an assistant provides countertraction by pulling on the sheet, apply longitudinal traction to the affected arm, manipulating the shoulder into reduction

Complications

  • Recurrent dislocation
    • 39% risk of recurrence after traumatic dislocation[11]
      • Risk factors:
        • Age <40 (approximately 90% recurrence rate in patients less than 20)
        • Male sex
        • Hyperlaxity
        • Bony Bankart lesion
        • Occupation
  • Bony injuries
    • Hill-Sachs lession
      • Compression fracture of humeral head
      • 40% of cases
      • Most likely with recurrent anterior dislocation
    • Bankart lesion
      • Injury to inferior glenoid labrum
      • 10-20% of cases
    • Bony Bankart lesion[12]
      • Fracture of anteroinferior glenoid rim
  • Axillary nerve injury
    • Up to 14% of cases
    • Usually self-resolves
  • Axillary artery rupture
    • Rare
      • Increased risk in chronic dislocation
  • Rotator cuff tear

Disposition

  • Discharge after successful reduction
  • Maintain in shoulder immobilizer until seen in follow-up by orthopedic surgery

References

  1. 1.0 1.1 Guler O, Ekinci S, Akyildiz F, et al. Comparison of four different reduction methods for anterior dislocation of the shoulder. Journal of Orthopaedic Surgery and Research. 2015;10:80. doi:10.1186/s13018-015-0226-4.
  2. Calvet, E et al. [Dislocations of the shoulder and vascular le- sions.] (in French). J Chir (Paris) 1941; 58: 337-346.
  3. Verhaegen F, et al. Chronic anterior shoulder dislocation: as- pects of current management and potential complications. Acta Orthop Belg. 2012 Jun;78(3):291-5. PMID: 22822566.
  4. Sahajpal DT, et al. Chronic glenohumeral dislocation. J Am Acad Orthop Surg. 2008 Jul;16(7):385-98.
  5. Intra-articular lignocaine versus intravenous analgesia with or without sedation for manual reduction of acute anterior shoulder dislocation in adults (Review) Cochrane Database Syst Rev. 2011 Apr 13;(4):CD004919 full text
  6. Neil Cunningham, MBBS, FACEM. "Cunningham Technique". Shoulderdislocation.net.
  7. Stafylakis D, Abrassart S, Hoffmeyer P. Reducing a Shoulder Dislocation Without Sweating. The Davos Technique and its Results. Evaluation of a Nontraumatic, Safe, and Simple Technique for Reducing Anterior Shoulder Dislocations. J Emerg Med. 2016 Apr;50(4):656-9.
  8. https://www.youtube.com/watch?v=u2MsnjVNoPM
  9. Sapkota K, Shrestha B, Onta PR, Thapa P. Comparison Between External Rotation Method and Milch Method For Reduction of Acute Anterior Dislocation of Shoulder. Journal of Clinical and Diagnostic Research : JCDR. 2015;9(4):RC01-RC03. doi:10.7860/JCDR/2015/11850.5738.
  10. Amar E, Maman E, Khashan M, et al. Milch versus Stimson technique for nonsedated reduction of anterior shoulder dislocation: a prospective randomized trial and analysis of factors affecting success. J Shoulder Elbow Surg. 2012 Nov;21(11):1443-9.
  11. Olds, M., Ellis, R., Donaldson, K., Parmar, P., and Kersten, P. (2015) Risk factors which predispose first-time traumatic anterior shoulder dislocations to recurrent instability in adults: A systematic review and meta-analysis. British Journal of Sports Medicine, 49(14).
  12. https://radiopaedia.org/articles/bankart-lesion