Terminology and classification of the pathology of the lumbar disc

Recommendations of the united working groups of the North American Spine Society, the American Society of Spine Radiology and the American Society of Neuroradiology,

These recommendations are diagnostic categories and subcategories designed for the classification and decoding of images (images). Each lumbar disc can be classified into one, and sometimes more than one, of the following diagnostic categories.

• Normal;
• Congenital / Developmental variant;
• Degenerative / Traumatic;
• Infectious / Inflammatory;
• Neoplastic;
• Morphological variant of uncertain value

Each diagnostic category can be divided into subcategories according to different degrees of specificity, according to the information available and the purpose of use. The information available for categorization can lead the researcher to use interpretations such as "possible", "probable" or "certain / exact."

General classification of disk damage

• Normal (except for age changes)
• Congenital / variant of development
• Degenerative / Traumatic Damage
• Tearing ring
• Herniation
  • Protrusion / Extrusion
  • Intervertebral
• Degeneration
  • Deforming spondylosis
  • Intervertebral osteochondrosis
• Inflammation / infection
• Neoplasia (swelling)
• Morphological variant of unknown value

Normal

The definition of "normal" implies young discs that are morphologically normal, without considering the clinical context and do not include degenerative, evolutionary or adaptive changes that could in some cases (for example, normal aging, scoliosis, spondylolisthesis) be considered clinically normal.

Congenital / variant of development

The category of congenital changes / development variant involves disks that have a congenital anomaly or have undergone a change in their morphology as an adaptation to abnormal spine growth, such as in scoliosis or spondylolisthesis.

Degenerative and / or traumatic injury

Degenerative and / or traumatic changes of the disk represent a broad category, which in turn is divided into subcategories: rupture (tearing) of the ring, hernia and degeneration. The description of this group of disk pathologies as degenerative / traumatic does not imply that trauma must necessarily be a factor or that degenerative changes necessarily have a pathological character, as opposed to the normal aging process.

Ring rings, also correctly called ring cracks, are manifested by fiber bundles (separations) of fibers of the ring, once from the fibers from their attachments to the vertebrae, or breaks of fibers located radially, perpendicularly, or concentrically, including one or more layers . The terms "tear" or "crack" do not assume that damage is a consequence of an injury.

Degeneration includes some or all of the actual or suspected processes: dehydration, fibrosis, disc height reduction, diffuse bulging of the ring beyond the disc area, numerous cracks (i.e., numerous ring tears) and mucoid ring degeneration, defects and sclerosis of the end plates, and osteophytes of vertebral apophyses. A disc in which one or more of these degenerative changes is observed can be further referred to as two subcategories: either spondylosis deformans, which is usually a disc alteration associated with the normal aging process; or intervertebral osteochondrosis (intervertebral osteochondrosis), usually a consequence of a more obvious pathological process.

Hernia is defined as a localized displacement of disc material beyond the intervertebral disk. The material of the hernia can be the nucleus, cartilage, fragmented apophysial bone, ring tissue, or any combination thereof. The space of the disc is limited: cranial and caudal closure of the vertebra, and peripherally - by the outer ends of the apophyses of the vertebral ring, except osteophytic formations. The term "localized" is contrasted with the term "generalized", where the latter, without sufficient grounds, is defined as more than 50% (180 degrees) of the disk periphery.

Focal mixing in the horizontal plane can be "focal", occupying less than 25% of the disk circumference, or "wide", occupying 25 to 50% of the disk circumference. The presence of a disc tissue occupying a circumference of 50% to 100% behind the edges of the apophyses ring may be called "bulge / bulge /" and is not considered either as a hernia or as a scattered adaptive change in the contour of the disc with adjacent deformity, which can occur in severe scoliosis or spondylolisthesis.

The hernia of the intervertebral disc can take the form of protrusion or extrusion, determined by the shape of the displaced material. A protrusion is observed if the greater distance in one plane or another between the edges of the material of the disk outside the disk space is less than the distance between the edges of the base in the same plane. The base is defined as the cross-sectional area of the disc material of the outer field of the original disc area where the disc material moved outside the disc space is inseparable from the disc material inside the disc space. In the craniocaudal direction, the length of the base can not exceed, by definition, the height of the intervertebral space. Extrusion is observed when, at least in one plane, any distance between the edges of the material of the disk outside the disk space is greater than the distance between the edges of the base, or when there is no continuity between the material of the disk outside the disk space and the same inside the disk space.

Extrusion can later be more accurately defined as sequestration (rejection of the necrotic area from the surviving tissues) if the displaced material of the disc has completely lost its connection with the parent disc. The term migration can be used to determine the movement of the material of the disc from the extrusion side, whether or not it is sequestered. Given that the later displaced disc material is often clamped by the posterior longitudinal ligament, the images can display the movement of the disc as a protrusion on the axial (longitudinal) cut and as an extrusion on the sagittal slice, in both cases the movement should be treated as extrusion. Herniated disc in the craniocaudal (vertical) direction through the rupture of the terminal plate of the vertebral body refers to the intervertebral hernia.

Herniated discs can be described as retention (fixed) if the displaced part is covered by an outer ring, or unstable (non-fixed) when no such coverage is present. The tissues of a displaced disc can also be described by location, volume, and content.

Description of a herniated disc

• Morphology
  • Protrusion
  • Extrusion.
  • In the body of the vertebra
• Retention
• Integrity
• Interrelation with the posterior longitudinal ligament
• Scope
• Composition
• Localization