traumatic anterior spondylolisthesis
Introduction
Introduction to traumatic anterior spondylolisthesis As the joint between the entire occipital-cervical complex and the lower cervical vertebra, the pivotal axis plays an important role in the biomechanics of the spine. The upper part of the anterior column is a dentate process, which forms the atlantoaxial joint with the arch and transverse ligaments and other accessory structures in front of the atlas; the intervertebral disc and the anterior and posterior longitudinal ligament are connected with the C3 vertebral body; the lamina of the posterior column and The spinous processes are relatively wide and solid, the spinous processes are long and the tail part is forked, and there are obvious morphological differences with other cervical spine processes. In the posterior cervical surgery, it can be used as an anatomical landmark for positioning; the column is weak. Before the upper joint protrudes, the lower joint protrudes, and there is a narrow bone connection between the two joint processes, usually called the isthmus. In the meantime, there is a vertebral artery hole crossing, which is an anatomically vulnerable part. Injury of anterior spondylolisthesis refers to bilateral pedicle fractures of the atlantoaxial joint with or without anterior slip. basic knowledge The proportion of illness: 0.002% Susceptible people: no specific people Mode of infection: non-infectious Complications: spinal trauma
Cause
Causes of traumatic anterior spondylolisthesis
Several major damage mechanisms:
(1) Hyperextension external force is a major injury mechanism of the isthmus fracture;
(2) As with the mechanism of using the underarm knot in hanging, there have been a large number of studies to determine this damage, called the Hang-man fracture, where the fold occurs in the foremost part of the lateral block, or into the pedicle, and The anterior longitudinal ligament, the rupture of the intervertebral disc and the posterior longitudinal ligament, the damage mechanism is overextension and sudden and violent stretch violence, resulting in the separation of the skull and neck, that is, the separation of the vertebral body and the cranial ridge as a whole, the rear The connection between the posterior axis and C3 is still intact, often causing spinal cord transection and immediate death, but there are some reports of this damage, even if there are transient neurological symptoms, this difference is interpreted as load direction and weight. As well as the application time, as a twisted type, he must be "suspended from the neck until he died". As time goes on, the critical soft tissue reaches the depletion load, causing the separation and death of the skull;
(3) In a car accident or diving accident, the damage mechanism is over-extension and axial compression violence. Stretching is caused by the frontal impact of the body, the forehead impacting on the inclined window glass or the bottom of the swimming pool, and the axial pressure is also involved. There may be a rotating component, Rogers noted a considerable number of cervical 3 vertebral compression fractures associated with a pivotal fracture, and other injuries that could not be explained by a simple stretching mechanism, 1 of his patients Accompanied by C7~T1 articular fractures, this strongly suggests that the axial pressure is opposite. In car accidents or other deceleration accidents, over-extension with axial compression violence acts on the pivot;
(4) In a few cases, buckling injury is the cause of Hangman's fracture.
In fact, there are a large number of cases of axial pedicle fractures, the combination of which depends on the specific violent vector involved, including the size, direction, point of action and duration of the violence. In general, the structure of the spine when the violence arrives. The unique mechanical characteristics of the spine structure of a particular patient determine the particular damage, the structural component of the disruption, and the degree of displacement. When a physician observes a traumatic anterior spondylolisthesis, the bending of the X-axis is a traumatic injury. The main component of violence, and the most likely mechanism involved is overstretching.
Prevention
Traumatic prevention of anterior spondylolisthesis
With regard to the prevention of traumatic anterior spondylolisthesis, the use of seat belts in car accidents can greatly reduce such damage. Of course, compliance with traffic regulations is most beneficial.
Complication
Traumatic anterior spondylolisthesis Complications, spinal trauma
Can be associated with soft tissue damage in the forehead, other vertebral bodies) and long bone fractures, other parts of the fracture, combined with right vertebral arteriovenous fistula.
Symptom
Traumatic anterior spondylolisthesis symptoms common symptoms paraplegia upper limb weakness bladder dysfunction
It was not until 1981 that the criteria for classification of the Hangman fracture occurred. First, Francis et al. divided the Hangman fracture into five grades according to the fracture displacement, angulation and ligament instability (Table 1). The measurement of the displacement was on the side. On the posterior C2, the posterior margin of the C3 vertebral body is drawn perpendicularly, and the perpendicular distance is measured; the angle is C2, the trailing edge of the C3 vertebral body is drawn separately, and the degree of intersection of the two lines is measured. The grade I fracture is considered to be stable. Grade II to IV fractures are unstable. Grade V fractures mean that displacement more than half of the sagittal diameter of the C3 vertebral body or an angular deformity has caused at least one side of the C2 to 3 gap to be greater than the height of the normal cervical disc.
Grade shift into angle (degrees) I <3.5mm <11 II <3.5mm >11 III >3.5mm or <0.5 vertebral body width <11 IV >3.5mm or >0.5 vertebral body width>11 V Intervertebral disc rupture.
In the same year, Effendi et al. divided the fracture into three types according to the stability of the fracture: type I is a stable fracture, the fracture line can involve any part of the vertebral arch, and the C23 interbody structure is normal; the type II fracture is an unstable fracture. The vertebral body shows flexion or extension of the angulation or obvious forward slippage. The C23 interbody structure has been damaged. The type III fracture is a displaced fracture. The vertebral body is displaced forward and has flexion. C23 Dislocation or interlocking of the facet joints.
In 1985, Levine and Edwards divided 52 patients with traumatic spondylolisthesis into four types according to the shape and stability of the fracture combined with the injury mechanism; the type I fracture had a slight displacement, the ligament injury was slight, and it was a stable fracture. 28.8%; the injury mechanism is the extension of the axial load caused by the axial arch in the extension of the extension position, type II fracture has more than 2mm forward and significant angle, is unstable fracture, accounting for 55.8%; damage mechanism It is an over-extension and axial load causing a nearly vertical fracture of the mid-bow. Subsequent sudden flexion leads to posterior fiber extension of the intervertebral disc and advancement and angulation of the vertebral body. The C23 disc may be due to the sudden buckling component involved in this injury mechanism. Fracture, type IIA fracture is a variant of type II fracture. C23 shows severe angulation and mild advancement. The fracture line is usually not vertical, but it is obliquely through the vertebral arch from posterior to anterior. Accounted for 5.8%, the injury mechanism is the main component of buckling with the traction component of the violence, type III fracture is bilateral pedicle fracture with posterior facet joint injury, usually accompanied by severe displacement and angle of the middle arch fracture And one side or The facet joint dislocation on both sides accounted for 9.6%, and the damage mechanism was flexion violence plus axial compression.
Although anterior traumatic anterior spondylolisthesis is a very dangerous injury, the incidence of neurological damage is relatively low, and sometimes even unbelievable. For example, only 4 of Levine's 52 cases have cervical spinal cord injury. There were 11 cases of unrelated nerve injury such as closed head injury, 29 cases of such fractures in Brashear, 1 case of left upper extremity spasm, initial recovery after 6 hours; 1 case of systemic temporary numbness; 1 case of central spinal cord syndrome After 5 weeks, only the left upper limb was weak; another limb was paralyzed, the whole body recovered completely after 25 days, and the incidence of nerve damage was relatively high. Tan reported 20 of 31 patients were asymptomatic and 7 Incomplete quadriplegia (3 cases of central tube syndrome), 2 cases of incomplete paraplegia, 2 cases of Brown-Sequard syndrome; 2 cases of complete bladder dysfunction, 11 of Marar's 15 cases with varying degrees of neurological damage, Six of them recovered after 24 hours, and 5 cases were slightly longer, but they recovered within 3 days to 3 months. The incidence of nerve damage and the degree of damage of such injuries may be due to the frontal fracture block. Pre-displacement produces a mid-bow defect In fact, the expansion of the spinal canal, the spinal cord also moves forward, and is protected from the compression of the posterior arch of the atlas, but when the fracture line involves the vertebral body, the posterior and posterior bone of the vertebral body remains in place. There is a risk of spinal cord compression.
The most common complaints are neck pain and stiffness, followed by numbness and weakness. The history of trauma is clear, often in a car accident or fall. Another clinical feature is the combination of head and maxillofacial injuries, located in the forehead or lower jaw. Mostly skin contusion, sometimes there are other vertebral bodies and bone fractures.
Examine
Examination of traumatic anterior spondylolisthesis
1. Ordinary X-ray examination: including cervical spine and tomography, the diagnosis of traumatic anterior spondylolisthesis mainly relies on lateral slices, and the lateral slices can clearly show the fracture line and the angle of displacement. To make an imaging diagnosis of the fracture type, under the guidance of the physician's accompanying protection, carefully perform cervical spine extension and flexion filming, which can further provide information on the stability of the fracture. There is a fashion need for a fault examination to clearly show the fracture line, typical of the X-ray. The performance is bilateral vertebral pedicle fracture, the fracture line is vertical or oblique, the vertebral body can have different degrees of displacement and angular deformity, and also need to pay attention to the atlas, the lower cervical vertebrae with or without fracture, to the baby Young children also need to pay attention to the possibility of congenital defects or cartilage connections of the vertebral pedicle.
2. CT examination: can clearly show the fracture line, displacement and the relationship with the spinal canal, CT three-dimensional reconstruction is ribbed in the comprehensive understanding of the fracture morphology, MRI examination can understand the condition of the spinal cord and surrounding soft tissue, the entire injury may have Comprehensive assessment and provide a basis for the choice of surgical approach.
Diagnosis
Diagnosis and diagnosis of traumatic anterior spondylolisthesis
diagnosis
Diagnosis can be performed based on clinical manifestations and examinations.
Differential diagnosis
It is not difficult to distinguish from cervical spondylosis by medical history and imaging examination.
