Thoracolumbar fracture dislocations are high energy injuries resulting in a highly unstable spine associated with neurologic deficit which often is complete. These are less common than burst fractures or flexion distraction injuries.
By definition, thracolumbar fracture dislocations are three column injuries. The mechanism of injury usually involves a combination of forces, including flexion, extension, shear, torsion, and compression.
These injuries are often associated with other musculoskeletal and visceral injuries often.
Fracture dislocations are caused by hyperflexion and rotation forces. One of the example is when a patient is ejected from a vehicle at high speed.
Evaluation of the patient is done in the same manner for any spinal injury.
Fracture dislocation of thoracolumbar spine is the most unstable spine injury involving all three columns of spine and, is associated with the highest incidence of neurologic deficits and chest and abdominal trauma. Involvement of all three spinal columns generally requires operative intervention to stabilize the spine and optimize neurologic recovery and patient rehabilitation.
Neurological deficit is more pronounced in fracture dislocations of thoracic than lumbar spine owing to lesser canal space in thoracic spine. It is estimated that 90% of fracture dislocations above T10 and 60% below T10 result in complete paraplegia.
Motor vehicle accidents account for majority of these injuries followed by falls from heights and sports related injuries.
Pathophysiology of Thoracolumbar Fracture Dislocations
Fractures dislocation of the thoracolumbar spine resulting from a combination of mechanisms, including compression, tension, rotation, and shear injury. Shear forces result, from posterior to anterior, in sequential failure of the posterior ligamentous complex, fracture of the lamina, buttressing of the facet joints, and, finally, anterior vertebral body compression.
The rotational injuries result in he fractures of the transverse processes and adjacent lower ribs. Dural tears and nerve roots trapping can occur in lamina fractures.
Presentation of Thoracolumbar Fracture Dislocations
A detailed history of the accident, if available must be noted as it provides insight to mechanism of injury. After initial stabilization, the patient should be examined for spinal deformity, tenderness and neural deficit.
A patient with fracture dislocation of thoracolumbar spine has a fixed gibbus and usually lies on his side with knees folded to maximize the residual diameter of the narrowed spinal canal.
Complete blood count, metabolic profile, blood grouping and cross matching clotting studies and urinalysis is done as presurgical preparation.
AP and lateral views of spine often demonstrate the severity of the injury.
CT gives valuable input on the injuries to the posterior elements. Empty facet sign is a complete dislocation of facet joints.
MRI is done for neurological injury especially when the neurologic examination findings do not correlate with the level of injury, Nervous tissue and disk injuries are better depicted by MRI.
Treatment of Fracture Dislocation of Thoracolumbar Spine
Fracture dislocations are associated with the highest incidence of neurologic injury and spinal instability. Therefore, for early mobilization and the chance for neurologic improvement, surgery is almost always required. Reduction of the dislocation, fixation with pedicle screw system and bone grafting for fusion. Either anterior anterior or posterior approach is used. Sometimes, both approaches may be necessary.
If the neurologic deficit is complete after spinal shock has recovered, neurologic recovery is unlikely, and surgery is performed or rehabilitation only.
A progressing neurological loss requires, urgent decompression and stabilization.
Complications of Fracture Dislocation Thoracolumbar Spine
Complications can either be due to operative procedure or secondary to effects of spinal cord or cauda equina injuries.
Compression of nerves due to positioning, dural tears, injury due to misdirected instrumentation, excessive bleeding and misplaced implant are common complications. Postoperative hematomas, cerebrospinal fluid leakage can occur.
The ultimate functional outcome is affected significantly by the patient’s age, body habitus, general condition, and cognitive and motivational factors. Depression can adversely affect the recovery and rehabilitative process. Incomplete injuries at the cauda equina level tend to have a more favorable recovery rate than to mixed conus or lower spinal cord injury.
Chronic urinary tract infections is a problem in e patient with paraplegia.
Simplification of daily routines can help in conserving energy and improving lifestyle where the full recovery has not taken place.