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Distal Humeral Fractures

Written by

Dr Owen Mattern
MBBS | Unaccredited Orthopaedic Registrar

26th February 2010

Definition

  • Fracture of the Distal humerus

Incidence

  • 0.5-7% of all fractures - 30% of elbow fractures

Classification

AO Classification

Jupiter / Mehne

Jupiter and Mehne Classification of Distal Humeral Fractures
Type Description
A high T
B low T
C Y
D H (free trochlea)
E / F Lambda (free trochlea)

Aetiology

  • Bimodal distribution
    • Young, high velocity injury
    • Elderly, osteoporotic female, low velocity injury

Pathology

Anatomy

  • Distal Humerus
    • 2 joints
      • Ulnohumeral
        • Flexion/extension
        • hinge joint, rotation axis 3-90 ER and 4-80 valgus to humeral shaft
        • Trochlea is centre of arch, supported by medial and lateral arc
        • 300 degree arch of cartilage
      • Radiocapitellar
        • Rotation
    • 2 columns
      • Medial
        • 45 degrees humeral shaft,
        • terminates at Medial Epicondyle
        • (MCL AP bundles, flexor and pronator mass)
      • Lateral
        • 20 degrees humeral shaft,
        • terminates at lateral supraconylar ridge/epicondyle (LCL and ext mass) and capitellum anteriorly

Neurovascular

  • Radial nerve
    • post cord C6-T1,
    • exits spiral groove 101-148mm from LEC and passes anteriorly through lateral intermuscular septum
    • not closer than 7.5cm above elbow joint,
    • anterior to elbow between brachialis and brachioradialis
  • Ulna nerve
    • medial cord C8-T1,
    • posteromedial humerus (superficial) around medial epicondyle, between FCU
  • Median nerve and brachial artery
    • Rarely damaged
    • medial and lateral cords C5-T1,
    • medial arm betwenn biceps/brachialis, cubital fossa, then between pronator teres heads, then FDS/FDP

History

  • Mechanism of Injury
  • Neurological

Examination

  • Ipsilateral limb fracture in up to 17%
  • Ulnar nerve palsy in up to 26%
    • intrinsics(hypothenar eminence, interossei, ulna lumbricals, ADDUCTOR POLLICIS - FROMENT’s SIGN), FCU and ulna FDP, paraesthesia 4/5th digits
  • Skin for open fracture

Investigations

Xrays

CT

  • 3D useful

Treatment

Basic Principles

  • EMST | ATLS principles
    • AO principles
    • Anatomic reduction
    • Rigid stabilisation
    • Early mobilization
      • Stiffness +++ after 2/52

Non-operative

  • Inidcations
    • Unwell older patients
  • However
    • Limited arm function
    • REMEMBER PROLONGED IMMOBILISATION = STIFFNESS +++

Operative

  • Options
    • ORIF
    • TEA
    • Hemiarthroplasty
  • Operative Approach
    • Universal posterior approach
      • Better outcome for both column injury
      • ? With ulnar transposition
      • Triceps sparing, triceps splitting, olecranon osteotomy
    • Medial or lateral for isolated column
  • ORIF
    • Superior outcomes to non-operative
    • AO priniciples
    • Distal to proximal
      • Reconstruct joint then attach to a column
    • Dual plating
      • Posterolateral/medial (orthogonal)
      • Medial/lateral (parallel)
    • Triple plating
  • Total Elbow Arthroplasty
    • Indications
      • Osteoporotic elderly
      • Inflammatory arthritis
    • Disadvantages
      • Activity restriction - lifting 1kg
      • Prosthetic concerns
  • Hemiarthroplasty
    • Distal humeral replacement
      • Proposed indications
        • Younger, comminuted, where ORIF is not able to be achieved
      • Absolute requirements
        • Intact/repairable collaterals
        • Ability to reconstruct affected columns
      • Minimal outcome data available
      • Some data suggests high complication rate (50%)
  • Treatment - ORIF vs TEA
    • 2 studies show improved outcomes for TEA v ORIF in patients >65 at 2 years
    • No difference in outcome if TEA done primarily or for failed ORIF

Post Surgery Rehabilatation

  • ORIF
    • Splinted in 30-400 flexion
    • Gravity and active-assisted ROM after wound healing
    • No resistance 8-12/52

Complications

  • Common
    • Stiffness
      • Especially terminal extension.
        • articular incongruity,
        • adhesions,
        • capsular contractions,
        • HO,
        • hardware impingement
    • ORIF - 11-29% (up to 48%)
      • Fixation failure,
      • nerve injury,
      • infection,
      • olecranon non-union,
      • HO

Prognosis

  • Post ORIF
    • flexion extension arc
      • 89 - 122 degrees
    • oomplications
      • 11 - 48 %
    • Good to excellent results in 62-100% patients
  • Total Elbow Replacement (elderly)
    • flexion extension arc
      • 101 - 107 degrees
    • complications
      • 5 - 29%
    • Good to excellent in 93-100%
  • Hemiarthoplasty
    • Minimal outcome data available
    • Some data suggests high complication rate (50%)

     

    Take home message

    • Difficult injury
    • Young patients
      • Reconstruct and ORIF
    • Elderly/osteoporotic
      • Consider TEA depending on fracture configuration
      • ORIF can be converted at a later stage