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*Manoj
Todkar
*Nuffield
Orthopaedic Centre, Windmill Road,
Headington,
Oxford, OX3 7LD
Address for Correspondence:
Manoj Todkar,
17 Girdlestone Close,
Headington, Oxford,
OX3 7NS
Tel: 07792404268
E-mail: mtodkar@hotmail.com
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ABSTRACT:
Transverse
fractures of vertebral arch or Chance fractures are associated
with lap-type seat belt use. In 1948, Chance (1) first described
a transverse fracture of the vertebral arch produced by a hyper
flexion injury of the spine. Since that time, the Chance
fracture is noted to be an unusual lesion in adults, very rarely
described in the paediatric patient (2). The fracture is most
frequently associated with injuries sustained while wearing
lap-type seat belts (3-5). This case reports a 30 year-old male
who sustained lumbar Chance fracture as a result of fall from
height.
CASE REPORT:
A thirty year-old male
fell from a height of 20 feet. He sustained close fracture of both calcanei, open
fracture of left tibia and complained of pain in lumbar area. Palpation revealed
tenderness in lumbar region. His neurological examination was normal.
Radiographs and CT scan revealed a transverse fracture of L2,
demonstrating split posterior elements and progressing anteriorly into body of
vertebra, as seen in the lateral X-ray of lumbar spine. For this fracture, L1 –
L3 fusion was carried out using metal cage from an anterior
approach and posterior instrumentation was added using pedicular screws.
External fixator was applied for open fracture of tibia and fracture calcaneum was
fixed internally on one side and other treated conservatively.
DISCUSSION:
The
Chance fracture consists of a horizontal splitting of the
spinous process and of the neural arch of vertebra, ending in
an upward curve which usually reaches upper surface of the
vertebral body and no lateral displacement or rotation of the
fracture fragments (1, 4). The fracture has been reported in
children to involve first, second, third and fourth lumbar
vertebrae (2, 6,7). The mechanism of injury is hyper flexion of
spine over a fulcrum. Howland et al (6) and Hubbard (7)
described Chance-type fracture of lumbar vertebra in paediatric
and adolescent age groups produced by lap-type seat belt acting
as a fulcrum across the spine at the time of injury. Smith and
Kaufer (5) reported a series of 20 patients with transverse
fractures of lumbar spine following injury while wearing
lap-type seat belts. They hypothesised that mechanism of injury
is one of sudden deceleration, such as occurs with automobile
crash or fall. With hyper flexion of the spine over a fulcrum
such as a seat belt, the force is displaced anteriorly and lies
at point of contact between fulcrum and the abdominal wall. This
subjects all of the components of spine to tension stress. The
result is a disruption of the ligaments of posterior elements of
spine or a transverse fracture of posterior elements. The same
type of injury may occur in a fall when the anterior abdominal
wall comes in contact with some object such as a tree limb or
fence, which acts as a fulcrum and forces the body into acute
flexion (4).Production of a Chance fracture in a fall over an
object acting as a fulcrum has been theorized but not commonly
reported in adults or children (5). Our patient in the report
fell from height of 20 feet. There was no history of an object
acting as a fulcrum involved in the fall. The calcaneal fracture
implies that the first contact with the ground was the feet and
that the acute flexion of the spine was a likely sequence from
that which resulted in fracture as a result of failure of bone
in tension. The recognition of Chance fracture is dependent on
high index of suspicion when the history of injury and clinical
examination are suggestive of hyper flexion injury of spine.
Patients presenting with bruises over lower abdomen must be
investigated carefully. A palpable tender gap over spinous
process may be the first indication of a flexion-distraction
injury. The incidence of neurological complications in
flexion-distraction injuries is low in patients who do not
frankly dislocate. These injuries may be associated with life
threatening intra-abdominal injuries that require immediate
attention. Lateral radiographs of the spine will confirm the
diagnosis. Definitive treatment of these injuries depends upon
the anatomic structures involved and the amount of displacement.
Lesions occurring entirely through osseous elements can be
managed in hyperextension orthoses. When the only osseous injury
involves the pars interarticularis, these are best managed with
open reduction and internal stabilization since pars has little
of cancellous bone. Injuries that primarily result from ligament
damage need to be addressed with open reduction and internal
stabilization since ligaments will not heal adequately to
provide stability if treated closed. Our patient had no back
pain at three months follow up. The bilateral calcaneal
fractures and the fracture of tibia also healed well. He
required no rehabilitation and returned to work at fourteen
weeks from the injury.
REFERENCES:
1.
Chance GQ. Note on a type of flexion fracture of the spine. Br J
Radiol 1948; 21:a452-a453.
2. Blasier RD, LaMont RL. Chance fracture in a child: A case
report with nonoperative treatment. J Paediatr Orthop
1985;5;92.
3. Rogers LF. The roentgenographic appearance of transverse or
Chance fracture of spine: The seat belt fracture. Am J
Roentgenol Raduim Ther Nucl Med 1971;111:844-889.
4. Horal J, Nachemson A, Scheller S. Clinical and radiological
long term follow-up of vertebral fractures in children. Acta
Orthop Scand 1972;43:491-503.
5. Smith WS, Kaufer H. Patterns and mechanism of lumbar injuries
associated with lap-seat belts.J Bone Joint Surg Am.1969
Mar;51(2):239-54.
6. Howland WJ, Curry JL, Buffington CB. Fulcrum fractures of the
lumbar spine. JAMA 1965;193:140.
7. Hubard DD. Injuries of spine in children and adolescents.
Clin Orthop 1974;100:56-65.
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