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Acute Elbow Dislocation

Epidemiology

  • 6/100 000
  • second most common dislocation (GHJ)
  • 90% elbow dislocations are posterior or posterolateral, note radial head + coronoid fractures
  • Rarer are anterior or lateral

Aetiology

  • Fall onto outstretched hand

Classification

  • Simple or complex dislocation (associated with fractures)
  • Final position of Ulna
    • Posterior
    • Posterior-Lateral
  • Degree
    • Complete
      • Disrupted Medial Collateral Ligament
    • Perched
      • <10 % pts
      • Disrupted Lateral Collateral Ligament ± Medial Collateral Ligament
    • Associated with fractures
      • 25-50%

Anatomy

Elbow Ulna Collateral Ligmaents
    Radial Collateral Ligaments of the Elbow
  • Lateral Collateral Ligament
    • Stability to Varus Force
    • 4 Components
  • Medial Collateral Ligament
    • Primary stabiliser to valgus stress

Pathology

  • Essential lesion for complete dislocation is involvement of medial collateral ligament (also lateral collateral)

History

  • Mechanism of Injury
  • Pain
    • wrist (Essex Lopresti)
    • shoulder

Examination

  • According to ATLS / EMST guidelines
  • Specific
    • Elbow
      • neurovascular status
    • Wrist
      • DRUJ stability (exclude Essex-Lopresti lesion, examine interosseous membrane)
    • shoulder
  • Jobe's Test
    • Patient standing
    • Flex elbow 25°
    • IR humerus for Valgus test
    • Place their hand in your axilla
    • Valgus stress & palpate Medial Collateral Ligament

Investigations

  • Xray
    • before & after reduction
    • widening of joint space indicates osteochondral fragments
  • CT Scan
    • if unable to reduce or suspicious of fracture / intraarticular fragment

Treatment

Initial

  • Post reduction assess stability + re-Xray + splint
    • Repeat Xray at week 1 to document reduction
  • If reduction is concentric & stable
    • gentle ROM exercises at 5-7 days, with sling for comfort
    • Aggressive therapy is associated with HO
    • Prolonged rigid immobilisation leads to poor ultimate range
    • ROM exercise within stable range initially
  • If mark instability
    • immobilize in sufficient flexion
    • Gradual extension from day 7
    • followed by gradual progression over next 3 to 4 weeks
    • Pronation also helps with stability
  • Flexion returns first, extension improvement can continue for upto 12 months
  • Recurrence 1 -2 %

Algorythm for treating elbow dislocations

Operative Treatment

Immediate closed reduction with GA

    • Longitudinal traction at 45° flex (to unlock coronoid) with direct pressure on Olecranon to assist
    • Estimate where stable & allow movement in that arc for 1/52
    • Then mobilize
    • If FFD at 6/52 > 40° then night extension splint
  • Will achieve :
    • 80% at 3/12
    • 100% at 12/12

Complete Dislocation with Radial fractures

  • Poor outcome if immobilized >4/52
  • Treat fractures according to type
    • Mason I = Reduce elbow
    • Mason II = ORIF
    • Mason III = Excise & Hinge splint
  • If Medial Collateral Ligament or Interosseous membrane (Essex-Lopesti fractures) injury, then need to insert spacer to avoid migration of Radial remmnant

Complete Dislocation with Coronoid fractures

  • See Morrey Class
  • Poor outcome related to fragment size ie Type II & III
  • >50% of coronoid
  • Leaves humero-ulnar articulation unstable

Complete Dislocation with Olecranon fractures

  • TBW or Neutralization Plate

Open reduction & Repair of Ligaments

  • Indications
    • All complete elbow dislocations result in medial + lateral ligament rupture but rarely is surgery indicated
    • Prospective studies show no advantage in early collateral ligament repair over early ROM
  • Indications for surgery
    • Flexion >50˚ required to maintain reduction
    • Associated unstable fracture
  • Operative procedure
    • Protect ulna nerve
    • Repair Medial Collateral Ligament + flexor/pronator mass, usually from humeral origin by intraosseous sutures or suture anchors
    • Repair lateral ligament complex. Kocher approach
    • ± hinged external fixateur. Dynamic external fixateurs are available. 3-4 weeks
    • Radial head ORIF = preserve posterior fibres Lateral Collateral Ligament complex (Lateral Collateral Ligament blends with the annular ligament laterally to insert on the proximal ulna
    • Incision is made anterior to midline of radial head, to preserve posterior fibres of Lateral Collateral Ligament)
    • Coronoid fracture = ORIF when >50% coronoid process fracture (note brachialis inserts coronoid base)

Complications

  • Stiffness
    • Most patients lose terminal 10-15˚ extension
    • Early active ROM prevents anterior capsular scarring
    • Consider elbow capsular release after 6 months
  • Heterotopic Ossification
    • Ectopic ossification = mature bone formation in nonosseous tissues
    • 75% of cases
    • HO that limits ROM <5%
    • Common sites = brachialis, collateral ligaments
    • Associated with aggressive ROM therapy, closed head injury
    • Resection is best delayed until ossification is matured on radiographs
  • DRUJ Instability
  • Essex-Lopresti lesion (originally described radial head fracture, dislocated DRUJ, without elbow dislocation)
  • Lateral Elbow Instability
    • Posterolateral rotatory instability occurs principally in supination
    • Xray = posterior radial head subluxation + ulnohumeral joint widening
    • ROM brace with forearm pronation