- 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.
PA Anderson et al.
J. Trauma. Vol 31. 1991. p 60-67.
- 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 thru 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.
Smith NS, Kaufer H:
J Bone Joint Surg (Am) 1969;51A:239.
The diagnosis and treatment of pediatric lumbar spine injuries caused by rear seat lap belts.
DL Johnson.
Neurosurgery. Vol 26. 1990. p 434-441.
