Chapter 16. Spinal injuries

Injuries of the spine account for up to 17% of all injuries of the musculoskeletal system.

Anatomical and physiological features

In the spine, there are cervical, thoracic, lumbar, sacrum, and coccyx. Due to the peculiarities of the anatomical structure, the upper cervical spine is considered as a craniovertebral junction. In the process of growth and development of the spine, cervical and lumbar lordosis are formed, thoracic and sacrococcygeal kyphosis, which transform the spine into a "spring system" that resists vertical loads.

The vertebra consists of a body, an arch, two legs, one spinous, two transverse, and four articular processes. In different parts of the spine, the vertebrae have their own structural features. So, the first cervical vertebra has two arches instead of the body, connecting with the lateral masses. All cervical vertebrae have foramina for the vertebral arteries in the transverse processes. Between the arch, the body and the legs of the vertebrae, there are vertebral foramina, from which the spinal canal is formed. Between the vertebral bodies, there are intervertebral discs, consisting of the annulus fibrosus and the nucleus pulposus. The ligamentous apparatus is represented by the anterior and posterior longitudinal, supra- and interspinous ligaments, yellow, intertransverse ligaments and the capsule of the intervertebral (zygapophyseal) joints. Two vertebrae with an intervertebral disc and a ligamentous apparatus represent the vertebral segment.

The spinal cord and "cauda equina" roots are located in the vertebral canal. The spinal cord is surrounded by hard, soft, and spider membranes, and is fixed in the spinal canal by roots and cellular tissue. In the dural sac, it is "suspended" on the denticulate ligaments. Between the soft and arachnoid membranes, there is a subarachnoid space containing 120-140 ml of cerebrospinal fluid. There are cervical (C_1-8), thoracic (Th_1-12), lumbar (L_1-5), sacral (S_1-5), and coccygeal (Co_1-3) sections of the spinal cord. The upper cervical segments of the spinal cord are at the level of the corresponding vertebrae, the lower cervical and upper thoracic are one vertebra higher than the vertebral bodies, in the middle thoracic region the difference is two, in the lower thoracic - three vertebrae. The lumbar segments correspond to the bodies of Th_11-12 vertebrae, sacral, and coccygeal - Th₁₂-L₁. The three lower sacral (S_3-5) and coccygeal segments constitute the cone of the spinal cord.

Classification

Injuries to the vertebrae are subdivided, according to the anatomy of the spine, into fractures of the cervical, thoracic, lumbar vertebrae, sacrum, and coccyx.

There are uncomplicated and complicated injuries.

Uncomplicated are called such damage to the vertebrae themselves and the ligamentous apparatus, where there is no damage to the spinal cord and its roots. Complicated are considered all injuries, which are accompanied by neurological disorders of any degree of severity.

There are also stable and unstable injuries, which are determined by the integrity of the bone-ligamentous complex of spine.

Unstable injuries admit a possibility of displacement of the vertebral bodies and/or bone fragments with the threat of compression of contents of the spinal canal - blood vessels, spinal cord, and its roots. In case of stable fractures, there is no such danger.,

Spine has three supporting complexes - anterior, middle, and posterior (Table 16.1, Fig. 16.1).

Table 16.1. Supporting structures of the spine

Fig. 16.1. Supporting structures of the spine

If only one support complex is damaged, the spinal injury is considered stable, two (in any combination), or all three - unstable. In addition, unstable ones include:

• all injuries of the vertebral segment accompanied by dislocation or subluxation of the vertebral body;
• fractures with wedge-shaped compression of the anterior vertebral body by more than a third of its height;
• flexion-rotational fractures;
• multi-splintered or "explosive" fractures (Fig. 16.2).

Fig. 16.2. Vertebral fractures: a) marginal (stable); b) with compression less than ¹/₃ of the body height (stable); c) with compression more than ¹/₃ of the body height (unstable); d) fracture-dislocation; e) "explosive"

Universal Classification of Fractures (Fig. 16.3) divided fractures of vertebral body into type A - damage to the vertebral body with compression; type B - damage to the anterior and posterior complexes with stretching; type C - damage to the anterior and posterior complexes with rotation. Cervical part of the spine has a more complex anatomical structure; therefore, fractures of the I and II cervical vertebrae have separate classifications, depending on the location of the damage, and injuries of the middle and lower cervical segments, which are unstable, are classified as type C.