History
Patients with lumbosacral fractures present with severe pain, deformity, and neurologic deficits related to compression of neural structures.
Fractures of the thoracolumbar junction can produce a mixture of cord and root syndromes caused by lesions of the conus medullaris and lumbar nerve roots. Complete damage of the conus medullaris is manifested as no motor function or sensation below L1. Patients with complete damage to the sacral portion of the cord have loss of control of bowel and bladder function and sacral motor paralysis of the lower extremities with preservation of some movement of the hips and knees and preserved knee jerks and sensation in the lumbar dermatomes.
Lower lumbar fractures may cause solitary or multiple root deficits. However, massive disk herniations, fracture-dislocations, and burst fractures in the lumbar region can cause a cauda equina syndrome with variable paraparesis, asymmetrical saddle anesthesia, radiating pain, and sphincter disturbances.
Physical Examination
The physical examination of a patient with an acute lumbosacral fracture usually is limited by severe pain. In the spinal examination, inspect the overlying skin for abrasions or contusions. Pay attention to general deviations from the normal spine curves. Muscle spasm from pain frequently flattens the spine, whereas spinal fractures may cause a kyphotic or scoliotic deformity. In addition, palpate the spine for areas of tenderness or fractured or displaced spinous processes.
Multiple traumatic injuries, [23] spinal shock, or sedation can make the initial neurologic examination difficult. Document any neurologic deficit according to the American Spinal Injury Association (ASIA) Motor Index. In all conscious patients, perform a motor examination. Muscle strength and weakness are graded from a strength of 5/5, considered normal, to a strength of 0/5, considered paralysis, as follows:
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Grade 0 - No contraction
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Grade 1 - Muscle contraction
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Grade 2 - Ability to move through a full range of motion when gravity is eliminated
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Grade 3 - Ability to move through full range of motion against gravity
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Grade 4 - Ability to move against resistance
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Grade 5 - Normal strength
The ASIA introduced the ASIA impairment scale, which consists of five degrees of impairment, as follows:
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A - No motor or sensory function is preserved below the neurologic level of injury extending through the sacral segments S4-5
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B - Sensory function, but not motor function, is preserved below the neurologic level of injury and extends through the sacral segments S4-5
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C - Motor function is preserved below the neurologic level of injury, and most of the key muscles below the neurologic level have a muscle grade of less than 3
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D - Motor function is preserved below the neurologic level of injury, and most of the key muscles below the neurologic level of injury have a muscle grade of 3 or higher
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E - Normal motor and sensory function are preserved
In addition, a detailed neurologic evaluation should include the following:
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Evaluation of sensory level
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Assessment of posterior column function
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Testing for normal and abnormal reflexes
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Examination of rectal tone and perianal sensation
The cutaneous abdominal reflex, the bulbocavernosus reflex, the anal wink, and the presence of the Babinski sign also should be noted and documented. The Beevor sign consists of a cephalic movement of the umbilicus when the patient is asked to elevate his or her head in the supine position. The presence of this sign denotes paralysis of the lower abdominal muscles. Always include a rectal examination to check for rectal tone and voluntary sphincter function.
Repeat the neurologic examination and document the findings at regular intervals to monitor for improvement or deterioration in the patient's neurologic status over time.
Spinal shock can last 24-48 hours, suppressing all reflex activity below the level of the lesion. The return of reflex activity (bulbocavernosus and anal reflexes) in the absence of any return of sensation or motor function generally is a poor prognostic indicator. Some return of motor or sensory function below the level of the lesion indicates the possibility of some return of useful neurologic function.
Complications
In 2013, the AOSpine Spinal Cord Injury and Trauma Knowledge Forum developed a simple classification of thoracolumbar spine injuries that included three primary types of fractures and nine subtypes. [24] In 2018, the AO Foundation and the Orthopaedic Trauma Association (OTA) issued a refined classification. [25] The three main types are as follows:
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A - Compression injury of the vertebral body
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B - Tension band injury
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C - Displacement/translational injury
Type A injuries are subclassified as follows:
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A0 - Minor nonstructural fractures (eg, spinous or transverse processes)
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A1 - Compression or impaction fractures of a single endplate without involvement of the posterior wall of the vertebral body
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A2 - Coronal split of pincer-type fractures involving both endplates without involvement of the posterior vertebral wall
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A3 - Incomplete burst fracture involving a single endplate with any involvement of the posterior vertebral wall
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A4 - Complete burst fracture involving both endplates as well as the posterior wall
Type B injuries are subclassified as follows:
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B1 - Monosegmental osseous failure of the posterior tension band extending into the vertebral body (Chance fracture)
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B2 - Disruption of the posterior tension band with or without osseous involvement; posterior tension band injury may be bone, capsule, ligament, or a combination
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B3 - Anterior tension band injury with disruption or separation of the anterior bone and/or disk with tethering of the posterior elements
Type C injury involves failure of all elements leading to dislocation, displacement, or translation in any plane or complete disruption of a soft-tissue hinge even in the absence of any translation. It can be combined with subtype A or B, allowing for two separate codes for an injury.
In addition, the following six neurologic grades are specified and are added to any spinal code to identify the neurologic deficit:
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NX - Cannot be examined
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N0 - Neurologically intact
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N1 - Transient neurologic deficit
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N2 - Nerve root injury
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N3 - Cauda equina injury or incomplete spinal cord injury
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N4 - Complete spinal cord injury
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+ Indicates there is ongoing cord compression in the setting of an incomplete neurologic deficit
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A 42-year-old man fell from a tree. He arrived at the hospital with a complete paraplegia. Plain radiographs reveal a fracture of L2 with L2-L3 subluxation.
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CT scan of a 42-year-old man who fell from a tree. He arrived at the hospital with a complete paraplegia (same patient as in Image above). Note the large amount of bone retropulsed inside the spinal canal.
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CT scan showing a burst of the L2 vertebral body.
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Postoperative lateral radiograph; although the patient was paraplegic, in order to prevent severe kyphotic deformity of the spine and to allow a rapid mobilization, a posterior arthrodesis was performed with pedicle screws, hooks, and rods.
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A 37-year-old man who underwent an anterior approach for an unstable L1 burst fracture. A corpectomy was performed, with a vertebral reconstruction with Harms cages and a screw to stabilize the cage. The patient subsequently underwent a posterior arthrodesis with iliac crest bone graft and transpedicular screw placement.
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A 52-year-old man was involved in a severe motor vehicle collision. He arrived at the hospital with severe pain but no neurologic deficit. Lateral plain radiographs show a fracture at T12.
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Sagittal T2-weighted image of a 52-year-old man who was involved in a severe motor vehicle collision. He arrived at the hospital with severe pain but no neurologic deficit (same patient as in the previous image). Image reveals a significant mass effect within the spinal canal.
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Patients with compression fractures not compromising the spinal canal can be treated by means of kyphoplasty. Use of a percutaneous balloon allows for expansion of the fractured vertebrae. Then, the void created by the balloon is filled with bone cement.
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Patients with an acute compression fracture treated with kyphoplasty. AP and lateral views demonstrate a good expansion of the compressed vertebral body and good filling with cement.
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A 47-year-old man was involved in a motor vehicle accident. He arrived at the hospital with paraplegia but preserved sensation in both lower extremities. He was immediately taken to surgery for an open reduction of the fracture, decompression of the cauda equina, and arthrodesis of the spine. He regained motor function following the surgery.
