Acute Shoulder Dislocation

Definition

  • Dislocation of Glenohumeral Joint

Aetiology

  • Usually as result of indirect force
    • Indirect ER in ABD moment 2° direct force on arm
  • Results in
    • Abduction
    • External rotation
    • Extension
  • Disruption of anterior stabilisers occurs

>Epidemiology

  • Commonest type of shoulder instability
  • Young males
  • Males > Females – 2:1

Anatomy

Pathology

  • Bankhart Lesion
  • Hillsach’s Lesion

Classification

According to direction seen on x-rays

  1. Subcoracoid
    • Most common
  2. Subglenoid
  3. Intrathoracic

History

  • Acute
    • History of Initial Injury
    • Severe pain in shoulder
    • ± Transient parasthesiae
  • History of Previous dislocations
    • Onset
      • traumatic, repetitive or voluntary
    • Position
    • Ease of relocation
    • Disability
    • Bilateral
    • Subluxation
  • No history of dislocation
    • Sensation of sliding
    • May have pain only
  • Neurological “Dead Arm Syndrome”
  • Other
    • joint laxity

Examination

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  • Very painful & tender shoulder
  • Significant muscle spasm
  • Arm held across abdomen
  • Hollow under acromion
  • Fullness in anterior shoulder
  • Nerve Palsy
    • axillary nerve palsy (10-20%)
    • Brachial plexus injury (20%)
  • Rotator cuff tear common in patient > 45 years of age

    • Investigations

    class="wp-block-heading">Xrayclass="wp-block-list">
  • True AP
  • True Axillary
  • If true Axillary impossible, use:
    • Oblique lateral
    • Garth
    • Velpeau axillary lat
  • Look for
    • Direction of Dislocation
    • Associated Hill Sach fracture

    • Differential Diagnosis

    class="wp-block-heading">Treatmentclass="wp-block-list">
  • Reduction
    • Reduction achieved as soon as is possible
    • Appropriate analgesia & muscle relaxation
    • Atraumatic closed reduction performed
    • Neurolept analgesia – Midazolam + Fentanyl
    • Propofol induction
    • If unsuccessful, may require GA
    • Rarely need open reduction
    • Post-reduction XR to
      • Confirm reduction
      • Rule out associated fracture

    • R>Reduction Maneuvers

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  • Stimpson
    • Patient prone
    • Arm hanging over side of bed
    • Weight applied to wrist
    • Scapula may be manipulated to facilitate reduction
  • Harvard
    • Patient supine
    • Traction with abduction
    • Countertraction or pressure in axilla
  • Modified Harvard
    • Patient supine
    • Traction with flexion
    • Counter traction in axilla
  • Hippocratic
    • Patient on floor
    • Stockinged foot in axilla
    • Axial traction
  • Kocher
    • Traction with slow ER & abduction followed by rapid IR & adduction
    • Large lever arm & ↑ risk of humeral fracture
    • Immobilisation
      • No effect on redislocation rate
      • No sport for 6/ 52 reduces dislocation rate
      • Protocol
    • Sling for comfort
    • Avoid provocation 6/52
    • No sport until painless FROM
      • Rehabilitation
    • Early intervention important

    Reh>Rehabilitation

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  • Immobilization (sling or splint)
    • No effect on redislocation rate
  • No sport for 6/52 reduces dislocation rate
  • Protocol
    • Sling for comfort
    • Avoid provocation 6/52
    • No sport until painless FROM
  • Rehabilitation
    • Early intervention important
    • Three components
      • 1. Start with ROM exercises
        • Pendulum Active Assisted Active
      • 2. Then shoulder strengthening
        • Rotator cuff & scapular stabilisers
        • Therabands
        • Isometric exercises
        • Especially internal rotation
      • 3. Avoid provocative arm positions in post injury period
  • Rehabilitation response (Rockwood)
    • 12% of TUBS
    • 88% of AMBRI
  • Outcome of non-op treatment is much better in the posterior than the anterior dislocations

    • Ear>Early Surgery

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  • Soft tissue interposition- SSP tendon
  • Displaced GT fracture
  • Large Glenoid rim fracture
  • Special problems – sport or occupation where patient needs absolute stability

    • Progn>Prognosis

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  • Factors of significance include
    • Age of patient at first dislocation
    • Degree of trauma & associated fractures at first dislocation
    • Activity
    • Rehab

    • Age a>Age at first dislocation

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  • Increased in young
  • Rowe CORR ‘61
  • Overall rate is 33%
    • McLaughlin & MacLellan 1967
      • 95% traumatic dislocations in teenagers recurred.
      • Various authors report 80 – 92 %
    • After the age of 40
      • incidence drops sharply to 10% to 15%.
    • The majority of recurrences occur within 2 years of the first traumatic dislocation.
    • Simonet & Cofield 1982
      • Overall incidence of recurrence
        • 33% over 4 years
        • 66% in patients < 20 years
        • 17% in patients 20 – 40 years
    • Athletes younger than 20 years was 80% but only 30% in nonathletes.

    Trauma >Trauma of First Dislocation

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  • Decreased incidence of redislocation with
    • Severe trauma
    • Associated Fracture

    • Activit>Activity

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  • Redislocation more common in athletes
  • 80% in athletes
  • 30% in non-athletes

    • Rehabil>Rehabilitation

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  • US Naval Academy study showed reduced redislocation following rehabilitation programme but high level of compliance required
  • Activity restriction & effective muscle strengthening reduces redislocation
  • Overall redislocation rate 25% at 3 years
  • Need strict adherence with program
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