Keywords
spinal fractures - burst fracture - dorsolumbar fracture - tipper truck injury
Road traffic accident is the most common mode of spinal injury. The incidence of burst
fractures is maximum at the thoracolumbar junction because the thoracic spine has
unique anatomical and biomechanical features. Minimal encroachment of spinal canal
at this level may produce severe deficits.[1]
[2] We introduce two new peculiar cases of dorsolumbar burst fractures secondary to
a peculiar tipper truck injury to the literature.
Case Description
Case 1
A 35-year-old male nonrestrained tipper driver was unloading sand from his tipper.
At the time of elevation of the tipper, he had forgotten to open the tail gate of
the body of the tipper, and as a result the whole load of the sand got accumulated
at the lower part of the body of the tipper and resulted in imbalance and overturning
of the truck. The truck driver sustained severe impact on his back, which caused pain
at the local site along with inability to move the lower limbs. He did not lose consciousness
during this episode. He was rescued by the bystanders and shifted to the Accident
and Emergency department of our hospital within 4 hours of the injury. He received
methyl-prednisolone-succinate 30 mg/kg stat and 5.4 mg/kg/h for the next 23 hours.
On examination he was conscious and coherent. The upper limbs were normal. He had
grade 0/5 power in both the lower limbs. There was complete loss of sensation below
D11–D12 level. Imaging revealed burst fracture of D-12 vertebra ([Fig. 1A]). He underwent transthoracic-retropleural 11th-rib bed approach; D-12 corpectomy
and instrumentation was done using two titanium 6- × 35-mm screws and a nonexpandable
cage. There was a dural tear that was sealed with fibrin glue and gel foam. There
was severe thecal sac compression. All the fragments within the canal were removed.
Wound was closed in layers over a vacuum drain. Postoperative period was uneventful
and X-ray showed instrumentation in place ([Fig. 1B]). On a follow-up of 3 years, there has been no improvement in his neurologic status.
He also has been experiencing severe neuropathic pain in both his lower limbs for
which he receives pregabalin on and off.
Fig. 1 (A) MRI sagittal section shows fractured D-12 vertebral body causing severe thecal sac
compression and signal changes in the cord. (B) Postoperative X-ray showing aligned spine with instrumentation in place.
Case 2
A 42-year-old male nonrestrained tipper driver was unloading boulders from his tipper.
At the time of elevation of the tipper, he forgot to open the tail gate of the body
of the tipper and the truck overturned. He also had an impact over his back and experienced
severe pain along with inability to move his lower limbs. He was rescued by the bystanders
and shifted to the Accident and Emergency department of our hospital within 10 hours
of the injury. Methyl-prednisolone-succinate was not administered to him. On examination,
he was conscious and oriented. The upper limbs were normal. He had grade 0/5 power
in both the lower limbs. There was complete loss of sensation below D-12 level. Imaging
revealed burst fracture of L-1 vertebra ([Fig. 2A] and [B]). He underwent translumbar retroperitoneal 12th-rib bed approach; L-1 corpectomy
and instrumentation was done using two titanium 6- × 40-mm screws and a nonexpandable
cage. The spinal canal was cleared of all the bony fragments. A titanium rod was put
between the screws. Wound was closed in layers over a vacuum drain. Postoperative
period was uneventful. On a 6-month follow-up, he has not improved in neurologic status.
Fig. 2 CT scan sagittal (A) and axial (B) sections show fractured L-1 body with intracanalicular bone fragments.
Discussion
Road traffic accident is the most common mode of spinal injury. The largest proportion
has been observed in West Africa at 89%. The lowest proportions are found in Greenland
at 4% as well as in Pakistan and Nepal both at 7%. Sports accidents causing spinal
cord injuries occur most frequently during diving, gymnastics, and rugby. From Russia
it has been reported that 33% of all accidents occurred during gymnastics.[1]
[2]
[3]
[4]
[5]
[6] As per report of the International Conference (Spinal Injuries Management, New Delhi,
1995), the incidence of spinal injury was estimated at 15 new cases per million per
year in India. This translates into 15,000 new cases per year, and with a backlog
of 10 years, the prevalence exceeds 0.15 million.[7]
Spinal injury due to this type of peculiar accident has not been reported before ([Fig. 3A] and [B]). The thoracic spine has unique anatomical and biomechanical features. It is much
stiffer than the lumbar spine because of restraining effect of both the rib cage and
its relatively thinner discs. Moreover, the spinal canal in dorsal region is narrower,
and hence even a minimal encroachment of spinal canal may produce severe deficits.
Also, the blood supply of dorsal cord is relatively sparse as compared with the other
areas of the cord, and hence could explain the occurrence of spinal cord injury with
less compression or kyphotic deformity than in the lumbar spine.[8]
[9]
[10]
[11]
Fig. 3 Schematic representation showing the normal unloading from truck when the tail gate
is open (A) and when not opened (B).
Spinal fractures are classified into minor and major fractures. Minor fractures include
fractures of spinous process, laminae, and pars interarticularis. Major fractures
are classified into four main categories; burst fractures, compression fractures,
fracture dislocation, and seat-belt injuries. Burst fractures were first described
by Holdsworth in 1963.The incidence of burst fractures is maximum at the thoracolumbar
junction and occurs frequently in high-energy traumas that are most commonly associated
with falls and traffic accidents. Holdsworth proposed a two-column model of spinal
stability by separating the spine into an anterior weight-bearing column of the vertebral
body and a posterior tension-bearing column of the posterior ligamentous complex (PLC).
He termed burst fractures as unstable if the PLC was disrupted.[12] Denis in 1983 described a three-column classification of spinal fractures. He proposed
that injury to the middle column, that is, the posterior portion of the vertebral
body, posterior longitudinal ligament, and posterior disc was sufficient to create
instability. He also classified unstable fractures into three types: mechanical (first
degree), neurologic (second degree), or combined mechanical/neurologic (third degree).[13] In 1994, McAfee et al proposed another classification and treatment scheme. He classified
the injuries based on how the middle column failed, with burst fractures exhibiting
middle column failure in compression. He also distinguished between burst fractures
with and without PLC disruption. A burst fracture with PLC disruption is considered
to be unstable. It is widely accepted that the posterior ligaments have probably failed
if there is greater than 30 degrees of kyphosis and/or 50% of vertebral body height
loss on plain radiographs.[14] Zeng et al also found stress concentration at the base of the pedicle, so they believe
that the injury initiate as from the base of the pedicle. In this study, stress concentration
was noted at the pedicle.[15] Of note is that all burst fractures are characterized by a rupture of the posterior
wall of the vertebral body and a shift of fracture fragments to the spinal canal.
These fractures fragments occupying the spinal canal can lead to compression of nerve
roots, cauda equina, or spinal cord, and/or spinal stenosis, resulting in clinically
evident neurologic symptoms. Burst fracture is a result of a compressive high-energy
injury (axial loading), and it mostly occurs at thoracolumbar junction where there
is fulcrum of increased motion that makes it more vulnerable to traumatic injury.
Primary force is an axial load to the vertebral body, which leads to end plate failure
as disc, is driven into the body. It may or may not involve a flexion bending moment.
Posterior column may fail in tension. Both the drivers had such an impact on their
backs when their respective trucks capsized and landed, which caused their upper torso
to be thrown forward, hence causing flexion at the dorsolumbar junction resulting
in spinal fracture.[16]
The indications for surgical treatment in spinal fractures are as follows:
-
Neurologic impairment
-
Canal encroachment (50%)
-
Vertebral body wedging (50%)
-
Kyphosis (25 degrees) at the injury level, measured between the upper and lower adjacent
noninjured vertebrae.
The surgical treatment of spinal burst fracture include anterolateral approach as
this approach offers optimal chance of canal clearance and also limits the number
of motion segments fused. Posterior approach no doubt is more familiar to a neurosurgeon,
but it has the disadvantage of inadequate spinal canal decompression. Anterolateral
approach with screws, cage, and rod instrumentation is becoming the standard now in
the management of burst fractures.[17]
Conclusion
Dorsolumbar burst fractures are not uncommon disabling spinal injuries. Efforts to
generate awareness of the truck drivers who drive tippers about the mechanism and
morbidity of such injuries may in future reduce the number of such peculiar accidents
and consequent morbidity.
