USC Center for Spinal Surgery
A thoracolumbar fracture means that a bone is broken in the thoracic (middle) or lumbar (lower back) region of the spine. There are approximately 15,000 thoracolumbar fractures each year in the U.S., and nearly 1/3 of these injuries are associated with a neurologic injury or paraplegia. The majority of thoracolumbar injuries occur at the T11-L1 level, which is the transitional zone between the relatively immobile thoracic spine and flexible lumbar spine. A low-energy injury is more likely to cause an injury to the intervertebral disc, yet a high-energy trauma such as a motor vehicle accident or fall is more likely to fracture the bone. Thoracolumbar fractures and dislocations are typically classified according to their injury/fracture pattern, as described by Denis.
A compression fracture, by definition, affects only the anterior column and does not compromise the posterior wall of the vertebral body or cause bony comminution or compression of the neural elements. A burst fracture affects the anterior and middle column, and in severe cases, causes instability of the posterior column. There is a fracture involving the posterior wall of the vertebral body, which can protrude posteriorly and cause spinal canal compromise and neurologic injury. Chance fractures primarily affect the posterior column, either by a ligamentous disruption or fracture through the spinous process and vertebrae. Fracture/dislocations of the thoracolumbar spine are the most severe injuries and are generally associated with an injury to the spinal cord or neurologic structures. The fracture and ligament damage typically involves all three columns, and the vertebrae are often drastically mal-aligned and displaced from one another.
Thoracolumbar Fracture Types
The most common causes of thoracolumbar fractures are motor vehicle accidents, falls, violence, and sports activities. The abrupt impact and/or twisting of the back that occurs in a millisecond during the trauma can cause the spine bones to crack or the ligaments to rupture, or both. The initial trauma or event may cause a thoracolumbar fracture and/or instability, which may also cause damage to the spinal cord and neurologic structures. The resultant spinal cord injury and neurologic deficit, if it occurs, is the most devastating aspect of a thoracolumbar injury, primarily because it is often irreversible and permanent. The majority of spinal column and spinal cord injuries occur in males between the ages of 15 and 24 years-old.
Patients with thoracolumbar fractures typically have significant, localized back pain and stiffness. However, patients with other injuries may complain of pain in other areas and not notice the severity of back pain. Patients who have neurologic compression or irritation may have numbness or weakness in the legs. There may or may not be associated radiating pain symptoms. Patients with thoracolumbar fractures may also have injuries to internal organs, such as the kidney, liver, intestines, and/or spleen, which may cause abdominal pain and distension.
The physical findings for patients with thoracolumbar fractures are variable. Patients will typically demonstrate profound tenderness and spasm, with significantly decreased lumbar range-of motion. There is often visible swelling and ecchymosis (bruising) over the fracture site in the back. If the fracture/dislocation is severe, there will be a visible and palpable "step-off", meaning the bones are not lined up properly which can be seen and felt by the examiner. If the spinal nerves are severely compressed, there may be significant weakness and numbness in the legs. Patients will have complete loss of strength and sensation in the setting of a complete spinal cord injury. Deep tendon reflexes may be diminished or absent. Pulses and vascularity of the legs should be normal.
Plain x-rays of the thoracic and lumbar spine are essential to adequately evaluate a thoracolumbar fracture. It is sometimes difficult to see a non-displaced or minimally displaced fracture or instability, therefore a Computed Tomography (CT) scan is usually ordered. A CT scan is the best test to verify that a fracture is or is not present. It is generally always recommended to obtain a CT scan when evaluating a burst fracture, Chance fracture, or fracture/dislocation, so one can evaluate for spinal canal compromise and facet joint congruity. A Magnetic Resonance Imaging (MRI) test is useful to evaluate the severity of nerve compression or spinal cord injury, but is less accurate at detecting a fracture than a CT scan.
There are no laboratory tests used to diagnose a thoracolumbar fracture. Occasionally, specific tests are ordered to rule out infection or other metabolic conditions that may be suspected as an underlying cause. For instance, serum protein electrophoresis and urine protein electrophoresis tests are ordered to evaluate for multiple myeloma, the most common form of bone cancer in elderly patients and frequent etiology of pathologic compression fractures.
A thoracolumbar spine fracture should always be suspected when a patient has been involved in a trauma or accident, especially those patients with back pain. The diagnosis can be complicated when the symptoms or physical findings are atypical. Some patients with other fractures or injuries will complain about pain in other locations, but not complain of back pain. At times, patients may downplay the severity of the motor vehicle accident or trauma. These scenarios may sway the clinician away from ordering thoracic and lumbar x-rays and imaging studies, which are crucial in the diagnosis of thoracolumbar injuries. It is important for the clinician to conduct a thorough history and clinical examination (especially inspection and palpation of the spine) prior to formulating a diagnosis so as not to misdiagnose this condition. Any patient involved in a severe accident or trauma, especially those patients with back pain, should be carefully evaluated with x-rays (and additional imaging studies if necessary) to accurately diagnose a thoracolumbar injury.
The treatment options for patients with a thoracolumbar fracture can be categorized as conservative (nonoperative) and surgical (operative). Nonoperative treatments include brace (orthotic) treatment and medications. There is a wide range of thoracolumbar orthoses, and range from soft corsets to hard plastic thoracolumbosacral orthoses (TLSO). Although frequently used in the past, it is now uncommon for patients with thoracolumbar fractures to be placed in a body cast. Surgical treatments frequently involve posterior (back incision) spinal fusion (mending the spine bones together) and instrumentation (small metal screws and rods stabilizing the spine). Other options include anterior (front of abdomen or flank incision) decompression and fusion, with or without instrumentation (metal plate and screws). Severely unstable fractures may require anterior and posterior spinal surgery. The overall goals of treatment are to preserve or improve neurologic function, provide stability, and decrease pain. If these goals can be accomplished with conservative (nonoperative) means, then that is generally preferred. However, some thoracolumbar fractures and dislocations are highly unstable and will not adequately heal on their own, and surgical stabilization must be performed. Surgical decompression (removal of bone fragments off of the spinal cord) many also be necessary to maximize a patient's chances for neurologic improvement and recovery from a spinal cord injury.
The general guidelines and treatment recommendations for various types of thoracolumbar fractures are listed below.
Although there are guidelines for the treatment of thoracolumbar fractures and dislocations, the specific treatment of a thoracolumbar fracture and/or dislocation ultimately depends on a number of factors.
The clinician should carefully evaluate a patient's injuries, and with the general management guidelines for thoracolumbar fractures in mind, individualize the treatment based on all of the above-mentioned factors.
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