Elbow Dislocation

  • Posterolateral is the most common type of dislocation (80%)

  • Usually a combination of

    • axial loading

    • supination/external rotation of the forearm

    • valgus posterolateral force

  • Pathoanatomic cascade: progression of injury is from lateral to medial

    • LCL fails first (primary lesion)

      • by avulsion of the lateral epicondylar origin

      • midsubstance LCL tears are less common but do occur 

    • MCL fails last depending on degree of energy

Types of Elbow dislocationOrthop Clin North Am. 2015 Apr;46(2):271-80

Types of Elbow dislocation

Orthop Clin North Am. 2015 Apr;46(2):271-80

 

Elbow Stabilizers : Static and dynamic stabilizers confer stability to the elbow

  • static stabilizers (primary)

    • ulnohumeral joint

    • anterior bundle of the MCL

    • LCL complex (includes the LUCL)

  • static stabilizers (secondary)

    • radiocapitellar joint

    • joint capsule

    • origins of the common flexor and extensor tendons

  • dynamic stabilizers

    • muscles that cross the elbow joint, which apply compressive (stabilizing) force

      • anconeus

      • brachialis

      • triceps

 
dislocation2.png
Medial ligament

Medial ligament

Lateral ligament

Lateral ligament

  • Clinical findings

    • Pain and swelling

    • Deformation

    • Check the status of the skin

    • Check the presence of compartment syndrome

    • Check neurovascular status

    • Check the status of wrist and shoulder

  • Imaging

    • Xrays : AP + Lateral

    • CT Scan: usually after reduction

In front of every elbow dislocation, we must search for Terrible Triade injury which is characterized by:

  • Elbow dislocation (often associated with posterolateral dislocation or LCL injury )

  • Radial head or neck fracture

  • Coronoid fracture

Structures of elbow fail from lateral to medial 

  • LCL disrupted first

  • anterior capsule injured next

  • possible MCL disruption

Terrible Triad injury

Terrible Triad injury

Treatment : Closed reduction and then assess :

  • If Stable: splinting at least 90° for 5-10 days, early therapy

  • If unstable: Operative treatment

    • If radial head is fractured : Osteosynthesis or prosthesis, but never excision

    • If elbow remains unstable : repair radial collateral ligament (the most important is the ulnar lateral collateral ligament)

    • If elbow remains unstable, repair the Coronoid process ( If >10% fractured)

    • If elbow remains unstable, repair ulnar collateral ligament

    • If elbow remains unstable, put external fixator (Hinged)

 

We should alert every patient with an elbow dislocation that it is impossible to regain his full range of motion.