Orthopaedic Jobs

Flexion-Distraction Injuries (Seat Belt Types)



- See:
       - Chance Frx:
       - Fracture Dislocation:

- Definition:
    - flexion distraction injuries may occur thru bone or soft tissue, and they may involve one or several levels;
    - flexion distraction injuries occur secondary to distractive disruption of posterior & middle columns w/ compression failure of 
           anterior column;
    - Chance Frx:
           - anterior, middle, and posterior columns all fail in tension;
    - mechanism of injury:
    - associated injuries:
           - most common injuries in lap belt restrained passengers are bowel trauma and lumbar spine frxs;
           - crushing of the bowel between the lap seat belt and spinal column results in devascularization or acute bowel rupture;
           - references:
                  - The epidemiology of seatbelt-associated injuries.

- Radiographs:
    - increased interspinous process distance on AP view;
    - lateral view:
          - increased posterior height of vertebral body is seen on lateral film;
          - split spinous process is seen, esp on lateral tomograms;
    - often these are misdiagnosed as a compression frx;
          - the occurance of a traumatic compression fracture in a young patient (following MVA) should raise the possibility of a Chance fracture;
          - either good quality AP view is necessary to rule out posterior element injury, or a CT scan is required (if the AP view remains 
                 equivocal);
    - CT is not of help in many distraction type of injuries because plane of injury is in the plane of the CT scan;
           - CT cuts tend to be a few milimeters above or below injury;

- Non Operative Treatment:
    - if injury goes through vertebral body rather than disc space, interdigitation of cancellous bone gives a great deal of immediate stability & 
           rapidly heals;
    - when these injuries occur entirely thru bone, treatment is in a hyperextension cast;
    - complications:
          - if there is crushing of bone frx can settle into kyphosis because of associated disruption of posterior interspinous ligaments;

- Operative Treatment:
    - when posterior and middle columns fail by ligamentous disruption, posterior spinal fusion with a compression system is advocated;
          - however, it is important to determine whether the middle column is capable of load bearing;
                 - if this is not the case, use of compression system could lead to retropulsion of bone or disk fragments into the canal



Anterolateral compression fracture of the thoracolumbar spine. A seat belt injury.

Seat-belt injuries of the spine in young children.

Pediatric Chance fractures: association with intra-abdominal injuries and seatbelt use.

Patterns and mechanisms of lumbar injuries associated with lapseat belts.

The diagnosis and treatment of pediatric lumbar spine injuries caused by rear seat lap belts.



Original Text by Clifford R. Wheeless, III, MD.

Last updated by Data Trace Staff on Thursday, April 12, 2012 9:50 am