Nomenclature and classification of lumbar disc pathology.

Definitions are based on anatomy and pathology. Definitions are not based on and do not imply specific etiologies (ie trauma), symptoms, or a need for a specific treatment. Normal-Free of disease, traumatic changes, or age associated changes Congenital / Developmental Variants-such as disc changes due to scoliosis or spondylolisthesis Degenerative & Traumatic Anular tear (synonymous with anular fissure)-separation, break, or avulsion of anular fibers; by definition does not imply traumatic etiology " Anular rupture " should be only when there is strong evidence of sudden violent injury to a previously normal annulus. (not synonymous with ruptured disc). Herniated Disc-general term for displacement of disc material (nucleus, cartilage, apophyseal bone, fragmented anular tissue)  Morphology: 1. Protruded (never sequestered), Extruded (+/-sequestration), or Intravertebral. 2. Protrusions can be " focal " (<25% curcumference) or " Broad Based " (25-50% of circumference)  Containment-refers to whether the outer anulus contains the herniated disc-usually cannot be determined by MR/CT  Continuity-(" sequestered " fragment is synonymous with " free " fragment)  Relation to PLL-subligamentous, extraligamentous, transligamentous, or perforated. If PLL is indistinct from anulus, the two structures combined can be called the " capsule " ; if the herniation is covered by the capsule, it can be called " subcapsular "  Volume-less than 1/3 of canal compromise = mild; 1/3 to 2/3 = moderate; > 2/3 = severe; similar for foramen  Location-central canal zone, subarticular zone (lateral recess); foraminal zone (pedicle zone) extraforaminal zone (far lateral zone). In sagittal/coronal plane: suprapedicle level, pedicle level, infrapedical level, disc level  " Symmetrical bulging disc " and " Asymmetrical bulging disc " (>50% of circumference involved) are not considered herniations Imprecise terms to be avoided: herniated nucleus pulposus (inaccurate), ruptured disc (inaccurate and implies trauma), prolapsed disc (imprecise when used nonspecifically), protruded disc (imprecise when used nonspecifically), and bulging disc (imprecise when used nonspecifically). Reporting:  Distinguish whether interpretations are solely based on morphological data or include clinical data  Classify each disc morphology into one (or more) broad category, and subcategory when possible  Include degree of certainty (Definite, Probable (>50%), Possible (<50%)) " Focal Protrusion " " Broad based protrusion "