30 year old gentleman presenting with injury to left elbow 2 days back

30 year old gentleman presenting with injury to left elbow 2 days back

30-year-old gentleman presenting with injury to left elbow 2 days back.

  • Figure A demonstrates fracture of coronoid process of ulna with fragment lying antero-superiorly. Posterior dislocation of ulna is also noted.
  • Figure B demonstrates  mildly displaced fracture of radial head with posterior dislocation of radius at radiocapetallar joint.
  • Figure C ; Volume rendered images clearly demonstrate both radial head and ulnar coronoid process fractures with posterior dislocation at elbow joint.

DIAGNOSIS:

  • Complex fracture dislocation at elbow as described above in keeping with Terrible triad of elbow.

Discussion:

  • The terrible triad of the elbow is a severe elbow fracture-dislocation pattern and is so-called because it has poor medium-to-long term outcome.
  • If inadequately treated; it can result in chronic instability and severe arthritis.
  • It occurs predominantly in adults; unlikely to be seen in children.
  • Mechanism of injury: Most commonly, a fall onto an outstretched hand, arm in semi-flexion and supination.
  • The fall is usually associated with a valgus posterolateral force which disrupts the capsuloligamentous structures sequentially from lateral to medial.

     

    • Computer-generated lateral three-dimensional (3D) view of the elbow demonstrates the normal anatomic configuration of the lateral collateral ligament complex, which includes the LUCL (red), RCL (blue), and annular ligament (yellow).
    • Computer-generated medial oblique 3D view shows the normal configuration of the anterior (red), posterior (blue), and transverse (yellow) MCL bundles.

Imaging features

  • The terrible triad of the elbow is the association of:
    1. posterior elbow dislocation
    2. coronoid process fracture
    3. radial head fracture
  • The posterior elbow dislocation usually involves the ulnohumeral joint.
  • The coronoid fracture usually involve the tip or are type I fractures (O’Driscoll Classification).

Points to add in report

  • Radial head fracture, coronoid process fracture (however small) with particular attention to anteromedial facet of ulna.
  • Radiocapitellar and ulnotrochlear articulation.
  • LUCL and MCL tears if possible.
  • Status of nerves if assessable.
  • Remember that volume rendering and MPR help in accurate estimation of severity of injury.

REFERENCES:

  1. Mathew PK, Athwal GS, King GJ. Terrible triad injury of the elbow: current concepts. J Am Acad Orthop Surg. 2009;17 (3): 137-51. J Am Acad Orthop Surg (full text) – Pubmed citation.
  2. Traumatic Elbow Injuries: What the Orthopedic Surgeon Wants to Know Scott E. Sheehan, George S. Dyer, Aaron D. Sodickson, Ketankumar I. Patel, and Bharti Khurana. RadioGraphics 2013 33:3, 869-888

Dr. Ashwini C. MD. FRCR.
Consultant Radiologist
Manipal Hospitals Radiology Group.

Dr. Sushant Mittal. MD
Cross-sectional fellow
Manipal Hospitals Radiology Group.