annular fissure

Annular fissures are a degenerative deficiency of one or more layers that make up the annulus fibrosus of the intervertebral disc.

Terminology

Many authors prefer the term annular fissure over annular tear, as the latter seems to imply acute injury . In the setting of severe trauma with disruption of the disc, then the term disc rupture should be used. The term annular gap (referring to a relatively wide annular fissure) is non-standard .

Clinical presentation

Most are asymptomatic, however, some are painful. The defect allows ingrowth of nerve endings and granulation tissue. Fissures near the dorsal root ganglion are especially likely to be painful.

Pathology

Annular fissures may be radial, transverse or concentric in orientation. The fissure may involve all layers or only some. The distinction is difficult if no disc extrusion is seen.

Radiographic features

Fluoroscopy

Discography (introduction of contrast into the nucleus pulposus) can help distinguish partial thickness or full thickness annular fissure, although the clinical relevance of this is disputed.

MRI

Although very common, only a minority are identified on MRI and are characterized by a region of high T2 signal (high intensity zone) in the otherwise low signal annulus.

Siehe auch:

• Grundlagen der Magnetresonanz-Tomographie
• annulus fibrosus
• Nucleus pulposus
• Nomenklatur Diskuspathologien

und weiter:

• spine nomenclature