Anterior shoulder dislocation

Background

• Shoulder dislocations account for 50% of all major joint dislocations, 90-98% are anterior
• Majority of anterior shoulder dislocations are due to trauma
• Important to rule-out axillary nerve injury

Clinical Features

• Arm held in abduction with shoulder lacking normal rounded contour
• Difficulty (painful) touching ipsilateral arm to contralateral shoulder

Chronic Anterior Dislocation

• Risk of axillary artery rupture in chronic dislocation
• A safe rule would be orthopedic consultation and proceed with caution in patients with 3-4 week dislocation

Differential Diagnosis

Shoulder and Upper Arm Diagnoses

Traumatic/Acute:

• Shoulder Dislocation
  • Anterior shoulder dislocation
  • Posterior shoulder dislocation
  • Inferior shoulder dislocation
• Clavicle fracture
• Humerus fracture
• Scapula fracture
• Acromioclavicular joint injury
• Glenohumeral instability
• Rotator cuff tear
• Biceps tendon rupture
• Triceps tendon rupture
• Septic joint

Nontraumatic/Chronic:

• Rotator cuff tear
• Impingement syndrome
• Calcific tendinitis
• Adhesive capsulitis
• Biceps tendinitis
• Subacromial bursitis
• Cervical radiculopathy

Refered pain & non-orthopedic causes:

• Referred pain from
  • Neck
  • Diaphragm (e.g. gallbladder disease)
• Brachial plexus injury
  • Rucksack paralysis
• Axillary artery thrombosis
• Thoracic outlet syndrome
• Subclavian steal syndrome
• Pancoast tumor
• Myocardial infarction
• Pneumonia
• Pulmonary embolism

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 in at least 2 views (axillary lateral or scapular "Y" view important to show anterior vs posterior displacement of humeral head)
  • Also need to rule out fracture-dislocation
• May not need pre-reduction X-ray 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 ortho for open reduction
• Procedural sedation usually used for reduction of shoulder dislocation
  • Consider intra-articular lidocaine (10-20mL) as alternative to procedural sedation.
• After reduction, apply sling with shoulder in adduction/internal rotation
• Ortho referral for 1st-time dislocation

Reduction Techniques

• Kocher

1. Place patient supine on exam table.
2. Adduct affected arm and bend 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, then internally rotate shoulder, moving hand towards contralateral shoulder.
5. Humeral head should slip back into place.

• Stimson

1. Place patient prone on edge of table.
2. If patient sedated or intoxicated, secure patient to stretcher with belts or sheets
3. Shoulder is placed over floor while the patient is prone so that the arm can fall 90 degrees to patient and floor.
4. Attach a 5-kg weight to the arm, and the patient maintains this position for 20–30 min, if necessary.
5. Occasionally, gentle external and internal rotation of the shoulder with manual traction aids reduction.
6. Consider combining with scapular manipulation (The inferior tip of the scapula is pushed medially and dorsally with the thumbs while the superior aspect of the scapula is stabilized with the fingers of the superior hand)

• Milch

1. Place patient supine on exam table (prone position also acceptable)
2. Hold affected arm by wrist, and slowly abduct and externally rotate the arm to 90 degrees each (arm over head position)
3. Using free hand, manipulate humeral head laterally and superiorly to achieve reduction.

• FARES (Fast, Reliable, and Safe) Method: (Sedation typically not required)

1. Apply traction while holding wrist to the affected limb in a neutral position beside on a supine patient
2. Oscillate limp up and down (anteriorly/posteriorly) while continuing to apply traction and start slowly abducting the limb.
3. Once abducted to 90 degrees, externally rotate and continue with ongoing traction and oscillations past this position. Reduction is usually achieved once abducted to 120 degrees.

• Cunningham Technique: (Sedation typically not required)

1. Massage the trapezius, deltoid, and bicipital muscle in the mid humerus in an alternate fashion
2. Maintain the the patient's affected arm adducted, and the elbow flexed, massaging the biceps
3. At the same time the patient is told to move the shoulder superiorly (up), and posteriorly (back) to allow the humeral head to relocate back into the glenoid fossae.

• Davos Technique,:

1. Standard pain medications
2. Pt is asked to hold injured ext with other hand and to flex knee ipsilateral as much as possible. Hands are placed ant to knee.
3. Hands are tied together using elastic band at the wrists, avoiding finger crossing which inc tension.
4. Elbows should be kept close to thigh.
5. Physician sits on ipsilateral foot and stabilizes hands.
6. Pt instructed to lean head back (neck ext exerts traction on injured shoulder) and let shoulders roll forward.

• Snowbird Technique

1. Patient sits upright in a chair with affected arm adducted at the side and elbow bent in 90 degree flexion
2. A looped stockinette is wrapped around the flexed elbow
3. Physician's foot pushes down on the stockinette to apply downward traction while the physicians hands hold the elbow at 90 degree flexion
4. An assistant stands on the opposite side with arms wrapped around the patient's chest under the axilla for countertraction

Complications

• Recurrent dislocation (>90% in age <20yr)
• Bony injuries (Usually do not affect management unless there is an associated humeral neck fracture in which case bedside reduction is contraindicated):
  • Hill-Sachs lesion (compression fracture of humeral head) - occur in up to 40% of cases; more likely with recurrent anterior dislocations
  • Bankart lesion (injury to inferior glenoid labrum) - occurs in 10-20% of cases
    • Surgical repair if: displaced >10mm, >33% of posterior glenoid fossa, >25% of anterior glenoid fossa, or persistent subluxation
• Axillary nerve injury - occurs in up to 14% of cases; usually transient deficits
• Axillary artery rupture - rare (except in chronic dislocation)
• Rotator cuff tear

Disposition

• Discharge after successful reduction