Basic concepts of thoracolumbar spinal cord injury Thoracolumbar spine generally refers to the thoracic 11-12 to the lumbar 1-2 spine, the spinal cord injury of this section of the spinal cord is called thoracolumbar spinal cord injury. Anatomical characteristics of thoracolumbar spine 1. Relatively small mobility. On the contrary, the lumbar spine has good mobility, large range of motion, and can be used for flexion and extension, lateral flexion and rotation. 2, thoracolumbar spine is more fixed thoracic vertebrae to the more active lumbar vertebrae conversion point, is the thoracic vertebrae protrusion to the lumbar vertebrae protrusion conversion point, the same is also the thoracic vertebrae synovial joints to the lumbar vertebrae synovial joints surface conversion place. Experimental studies have shown that the articular articulation of the articular eminence is easily damaged by rotational loads when it changes from the coronal plane to the sagittal plane, therefore, the thoracolumbar segment has the highest incidence of thoracic and lumbar spine injuries. 3, thoracolumbar spinal canal and spinal cord of the effective gap is relatively narrow, thoracolumbar spinal cord injury is easy to cause spinal cord compression. 4, thoracolumbar spine is a mixed part of spinal cord and cauda equina, even if the spinal cord is completely injured without recovery, but the nerve root injury may still have a certain degree of recovery. Second, the thoracolumbar segment injury causative factors thoracolumbar segment spinal injury is a common spinal injury, which has many causes, the main reasons are: 1, the vast majority is caused by indirect violence. Falling from a high place, foot and buttocks on the ground, so that the torso is violently bent forward, resulting in flexion-type violence, can also be due to bending down to work with a heavy blow to the back, shoulders, the same thoracolumbar vertebrae sudden flexion, so flexion-type injuries are the most common. There are also a small number of extensor type injury, the patient fell from a height, midway back due to an obstruction to make the spine over-extension, is an extensor type injury, but it is extremely rare. 2, direct violence caused by the thoracolumbar spine injury is rare, such as work injuries or traffic accidents directly hit the thoracolumbar region, or due to gunshot wounds. 3.Muscle tension, such as transverse process fracture or spinous process avulsion fracture, due to sudden muscle contraction. 4.Pathological fracture, that is, the spinal cord original tumor or other bone disease, its solidity is weakened, a slight external force can cause fracture. Classification of thoracolumbar spinal cord injury The thoracolumbar spine is the central pillar of the human body, and the thoracolumbar vertebral junction has more activities, which is the most vulnerable part of the injury. Maintaining its stability is the first and foremost, without stability, there is no normal function of the spine, therefore, after the thoracolumbar spine injury, we must consider whether to maintain its stability, so as to provide a basis for choosing reasonable and effective treatment. There are many classifications of thoracolumbar spinal cord injuries reported in the literature, all of which are aimed at selecting appropriate treatment and estimating the prognosis. Therefore, any classification should be based on the clinical, pathological and injury mechanisms, and it can be said that although there are many classifications at present, they are not yet perfect. Treatment of unstable fracture without nerve injury An unstable fracture is one in which the stabilizing factors of the segment are severely damaged, and if it is not perfectly fixed, there is a tendency for it to be displaced, which may aggravate the spinal deformity or cause secondary damage to the spinal cord and cauda equina. However, according to the literature, the treatment methods for unstable thoracolumbar spinal cord injuries are still different. (i) Conservative approach Positional repositioning is used and immobilization with a brace or plaster undershirt. The advantage is that the pain of surgery can be avoided, but the disadvantage is that the treatment time is long, the plaster undershirt must be fixed for 3-4 months, the repositioning may not be satisfactory, and there may still be residual spinal deformity, and it may cause damage to the spinal cord and the cauda equina. (B) Surgical treatment In 1953, Holdsworth proposed that all unstable fractures should be treated with early incision and repositioning, internal fixation with sphenoidal plate, early restoration of normal physiological structure, prevention of spinal cord and cauda equina injury or spinal deformity, and also for the care and prevention of various complications, and rehabilitation can be started in 3 months of recumbent position in general.In 1974, Lewis treated the unstable thoracolumbar spine with paraplegia, and found that conservative treatment could be used. In 1974, Lewis treated unstable thoracolumbar spinal fracture and paraplegia, and found that there was no significant difference between the nerve recovery of the two groups in the conservative treatment and incisional reduction and internal fixation, and the incidence of late back pain was higher in the conservative treatment group. 1980, Davis summarized the efficacy of conservative treatment of spinal fracture of thoracolumbar spine combined with nerve injury and found that the spinal deformity was aggravated in the day of closure and restoration, but it didn’t aggravate the nerve injury, and it had the advantages of no surgical complications and surgical risks compared with incisional restoration, but the hospitalization was not a good choice. Compared with incision, it has the advantages of no surgical complications and surgical risks, but the hospitalization period is longer. In recent years, most scholars advocate the use of strong internal fixation to ensure that the spine has enough stability to meet the requirements of early waking up and activities, facilitate the early recovery of neurological function, and reduce the complications.Denis advocates the use of prophylactic internal fixation and fusion surgery for burst fracture without neurological injury to prevent the so-called “late instability” secondary spinal cord and cauda equina due to the so-called “late instability”. Denis advocated prophylactic internal fixation and fusion of burst fractures without nerve injury to prevent so-called “late instability,” a series of syndromes associated with secondary spinal cord and cauda equina injuries and spinal deformities. With the development of science, internal fixation techniques and instruments have improved significantly, and most scholars and physicians believe that incisional internal fixation is a reasonable and effective method for treating unstable thoracolumbar fractures. Treatment of spinal cord and cauda equina injury Thoracolumbar fracture and dislocation combined with spinal cord and cauda equina injury, whether the neurological function can be restored is not only related to the degree of injury at that time, but also related to the affected spinal cord and cauda equina by the displacement of bone fragments and prolapsed intervertebral discs caused by the continuous compression, such as the compression is not lifted, it also affects the recovery of neurological function. Therefore, early repositioning and immobilization should be performed to avoid secondary injury to the spinal cord. （Generally speaking, spinal cord and cauda equina injuries caused by spinal trauma are mostly due to spinal fracture and dislocation. However, there are a small number of spinal cord injuries in which no signs of fracture and dislocation can be seen on X-ray, which is called non-fracture and dislocation type of spinal cord injury. It occurs mostly in younger pediatric patients. Because the spine is highly elastic in children, excessive traction can cause the spinal cord to fracture without fracture or dislocation of the spine. This type of injury is treated conservatively, without decompression, to avoid further damage to spinal stability and spinal cord function. Conservative treatment includes hard bed rest, high-dose hormone (methylprednisolone) shock therapy, dehydration, hyperbaric oxygen therapy, etc., to prevent or mitigate secondary damage to the spinal cord. For the thoracolumbar vertebrae with obvious fracture dislocation, some scholars once used postural treatment or forced traction reset of the lower limbs under general anesthesia, which has the danger of aggravating spinal nerve injury, time-consuming reset, laborious, ineffective, with a high failure rate and deformity, and is now eliminated. In recent years, with the development of surgical technology and material science, most scholars now advocate early surgical treatment, with strong internal fixation to maintain spinal stability, so that patients get up and move around as soon as possible, and also supplemented with other comprehensive treatment, which not only reduces the patient’s hospitalization time, but also more importantly, is conducive to the recovery of the patient’s systemic and neurological functions. (ii) Surgical treatment With the development of CT technology, the diagnosis level of spinal cord injury has been significantly improved. In the past 20 years, with the progress of spinal surgical treatment technology, the surgical treatment of acute thoracolumbar spinal cord injury has attracted attention again, and the early selection of the correct surgical treatment can achieve anatomical reset, restore the normal volume of the spinal canal, rebuild the physiological anatomical structure and stability of the spine, and promote the recovery of spinal cord function. Purpose of surgical treatment: (1) Surgically remove the fracture fragments, prolapsed discs or blood clots that compress the spinal cord, cones and cauda equina. (1) To reduce or prevent secondary damage to the spinal cord and cauda equina; (2) To remove toxic metabolites; (3) To explore the spinal cord, loosen adhesions, and promote the recovery of neurological function; (4) To rebuild the stability of the spinal column; (5) To prevent various complications. Indications for surgical treatment: (1) acute thoracolumbar spinal injury with incomplete spinal cord injury; (2) conservative treatment of paraplegia symptoms have not recovered, but gradually aggravated; (3) CT or MRI shows that vertebral fracture protruding into the spinal canal, disc herniation caused by compression, or depressed vertebral plate fracture; (4) interlocking of the lesser articular eminence; (5) X-ray shows that there is a fracture in the vertebral canal or a foreign body; (6) open spinal cord injury. (6) Open spinal cord injury; (7) Various types of unstable fresh or old spinal fractures. Choice of surgical approach: There is no effective measure for paraplegia caused by thoracolumbar spinal injury combined with spinal cord injury. Adequate decompression to maintain spinal stability is still a good treatment method, but the choice of surgical access is not consistent among scholars. Most scholars believe that the choice of surgical access should be based on the type of thoracolumbar spinal injury, segment, and direction of the compression. Anterior decompression, lateral anterior decompression, and laminar decompression all have their own advantages and disadvantages. It is difficult to solve each lesion with one pathway. From the cross-sectional view of CT and MRI images, the spinal cord is close to the anterior aspect of the dura mater. Thoracolumbar spinal injury, whether compression fracture or dislocation, most of the spinal cord compression comes from the anterior part of the spinal canal, and clinical treatment should emphasize anterior or lateral anterior decompression. If the compression comes from the dorsal side of the spinal cord, decompression of the vertebral plate is required. The greatest advancement in the treatment of paraplegia in the last 20 years has been the development of anterior or lateral anterior decompression. Removal of displaced fractures at the posterior margin of the vertebral body either anteriorly or posteriorly requires care. Anterior, anterolateral, and posterior approaches should be chosen according to one’s experience and condition, respectively. The general principle is to achieve decompression of the dural sac without aggravating spinal cord injury.