What Is the Thoracic Spine?

Thoracic vertebra, 12 in the thoracic spine. From top to bottom, the vertebral body gradually increases, which is related to weight bearing. The thoracic spine is involved in supporting the ribs and constituting the thorax.

Thoracic vertebra, 12 in the thoracic spine. From top to bottom, the vertebral body gradually increases, which is related to weight bearing. The thoracic spine is involved in supporting the ribs and constituting the thorax.

Chinese name

thoracic

Foreign name

Thoracic vertebrae

Including

Vertebral body, vertebral arch and protrusion

Thoracic nerve

12 pairs in total

Thoracic spine anatomy

The cross section of the vertebral body is heart-shaped. The upper thoracic vertebra is similar to the cervical vertebra, and the lower thoracic vertebra is similar to the lumbar vertebra. On the upper and lower edges of the posterior side of the vertebral body, there are upper rib depressions and lower rib depression and rib-related nodes. The upper rib depression is generally larger than the lower rib depression. The foramen are round and smaller than those of the cervical spine. In front of the transverse process there is a circular transverse process and the related nodules. The articular surface of the superior and inferior articular processes is similar to the crown (frontal) position, the articular surface of the superior articular processes is flat, and the inferior articular processes are slightly depressed. The spinous process of the thoracic spine is long, extending backward and downward, overlapping each other, showing a tile shape, the spinous processes of the upper and lower thoracic spines are flat, and the middle part is the most oblique.

The transverse diameter of the vertebral body of the first thoracic vertebra is twice as large as the sagittal diameter. The transverse diameter of the vertebral body below the second thoracic vertebra becomes smaller and the sagittal diameter increases. The transverse process becomes shorter from top to bottom. The 5th to 8th thoracic spinous processes are the longest.

The 1st thoracic vertebra has a circular upper rib and semicircular lower rib; the 9th and 10th thoracic vertebrae usually have only one upper rib; the 11th and 12th thoracic vertebrae have only one circular rib. Transverse process is short without transverse process.

Thoracic spine function principle mechanism

The thoracic spine has 12 vertebral bodies to bear the compression load, the vertebral arch mainly bears the tensile load, and the lamina is short and wide in the shape of a tile, which can prevent the thoracic spine from overextending. The articular surface of the articular process joint is coronal, so it allows a certain range of axial rotation of the thoracic spine and has a strong resistance to forward displacement. The vertebrae, intervertebral discs and ligaments maintain the stability of the thoracic spine. The stability of the thoracic spine is significantly higher than other spinal regions such as thoracolumbar, which is mainly due to the presence of the thorax ring. The sternocostal joint is formed by the costal cartilage and the sternum in the front, and the joint is formed by the rib head and the corresponding vertebra, intervertebral disc and transverse process in the rear.

Thoracic spine imaging structure

1. Right position. As a whole, the 12 thoracic vertebrae are arranged neatly straight or flexed slightly to the right. Each thoracic vertebra is square, the upper vertebra is smaller, and the volume gradually increases downward. The upper and lower edges of the vertebral body are dense and flat, sometimes with double shadows. The double shadow is the result of the vertebral anterior and posterior edges being developed separately. The sides of the vertebral body are slightly concave, so that the upper and lower ends of the vertebral body are extruded. In each vertebral body shadow, the dense circles on both sides of the vertebrae are the pedicle cross-section shadows. Because the spinous processes of the thoracic spine are relatively slender and have different inclination, the ends of the spinous processes are different. Generally, the spinous processes of the upper and lower thoracic spines are less inclined, and the cross-sectional shadows of their ends often overlap with the lower edge of the vertebrae; . The shape of the spinous process can be seen along the cross-sectional shadow of each end. There is a lamina between the upper end of the spinous process and the pedicle shadow on both sides, and most of the lamina overlaps the vertebral body. The upper edges of the vertebral plates on both sides form a concave arc, and the two ends of the upper edge of the arc extend above the pedicle shadows on both sides and form the upper articular process. Near the lower corners of both sides of the vertebral body, the lower edge of the laminar projection protrudes downward, forming a lower articular process. The upper and lower articular processes of two adjacent thoracic vertebrae overlap to form an intervertebral joint. On both sides of the vertebra, there are transverse projections protruding outward. The intervertebral discs were not visualized, showing only a transparent intervertebral space. All the intervertebral spaces are relatively tidy, with the upper space being narrower and slightly wider downward one by one.

2. Side position. The entire thoracic spine is slightly posterior, forming a chest curve. Each thoracic vertebra is rectangular and sometimes bilateral, and the left and right edges of the bilateral vertebrae are visualized separately. Generally, the front edge of the vertebral body is relatively straight, and some people have a slightly depressed middle part, which makes the upper and lower ends slightly protrude forward. With the increase of age, the protuberance is gradually obvious, then called the upper and lower lips. The posterior edge of the vertebral body is also relatively straight, and the cortical interruption caused by perforation of nourishing blood vessels can be seen in the middle. The vertebral body extends backward into the pedicle. The pedicle overlaps with the small head of the ribs, and the visualization is often unclear, except that the inferior edge of the pedicle is clearly visible. The upper end of the upper edge of the pedicle extends upwards into a pointed protrusion, that is, the upper articular process. The lower edge of the pedicle also extends rearward and downward into a pointed protrusion, that is, the inferior articular process. The adjacent upper and lower articular processes of the two vertebrae constitute the intervertebral joint. The lamina is between the upper and lower articular processes, and the spinous processes are the protrusions in the rear direction. The spinous process also overlaps with the rib shadow, and only the roots are clearer.

Thoracic spine auxiliary structure

1. Thoracic spinal nerves, a total of 12 pairs of thoracic nerves from the thoracic segment of the spinal cord, which penetrate through the lower edge of the thoracic spine, have anterior and posterior branches.

2. The thoracic sympathetic and spinal nerves can be called visceral nerves and regulate the activities of the visceral nerves. Among them, the thoracic heart nerve, the large visceral nerve, the small visceral nerve, and the lowest visceral nerve, etc. Gallbladder, pancreas, small intestine and kidney function. Therefore, the dislocation of the thoracic spine is closely related to the overall visceral function and general health.

Thoracic spine related diseases and treatment

1. Thoracic spine fractures can be divided into compression fractures, fracture dislocations, burst fractures, and burst dislocations according to the Hanley-Eskay classification.

2.Type and treatment principle: Type A is sternal fracture + thoracic spine fracture without spinal nerve injury (A1: sternal fracture + stable thoracic fracture without spinal nerve injury; type A2: sternal fracture + unstable thoracic fracture without spinal nerve Injury); type B is sternal fracture + thoracic spine fracture with incomplete spinal nerve injury; type C is sternal fracture + thoracic spine fracture with complete spinal nerve injury (the sternal fracture referred to in the classification does not include xiphoid fracture).

Although the thoracic vertebrae are stable fractures, the combined sternal fractures often cause potential instability. In order to reduce the possibility of thoracic posterior deformity aggravation or even delayed paralysis, early sternal fractures should be surgically fixed. Non-surgical thoracic vertebrae fractures can be taken non-surgically. treatment. This treatment is more clinically significant for patients with thoracic vertebral compression fractures and osteoporosis.

Type A2 thoracic vertebrae are unstable fractures. Due to the intact nerve function, decompression surgery is not necessary. The posterior fixation of the ascending sternal fracture can achieve a good stabilization effect.

Type B combined with incomplete spinal nerve injury should be actively treated with decompression surgery, total laminectomy or spinal canal decompression, total decompression of the spinal canal, interlaminal transverse process or intravertebral bone graft fusion, intra-instrumental Fixed, creating conditions for the recovery of spinal cord function. Reduction and fixation of sternal fractures is conducive to controlling pain at the fracture site and maintaining thoracic stability. Incomplete thoracic spinal cord injury has rarely been reported after nerve decompression.