Dimensions of the spinal canal in individuals symptomatic and non-symptomatic for sciatica: a CT study

Abstract

Measurements obtained in 50 spinal CT studies of patients referred for suspected lumbo-sacral nerve root compression, were compared to those of a group of 30 individuals asymptomatic in this respect, who had been referred for abdominal pathology. Transverse ligamentous interfacet and transverse dural dimensions were significantly reduced in the sciatica group, with usually normal interpedicular and sagittal dimensions ruling out idiopathic developmental stenosis. The borderline value for ligamentous interfacet distance (ILD) at L4-5 appeared to be 11 mm.

Relationship between sedimentation sign and morphological grade in symptomatic lumbar spinal stenosis

“…Radiological LSS is considered moderate when DSCA is less than 100 mm 2 and severe if DSCA is less than 75 mm 2 [1]. Nevertheless, there is a significant overlap in DSCA values between symptomatic and asymptomatic individuals [2]. To overcome those shortcomings, recently clinicians have been looking into morphological parameters to grade radiological LSS.…”

Pathologic Anatomy and Mechanisms of Nerve Root Compression

“…In patients with sciatica the same average value is 11.2 mm. The borderline value is 11 mm (Wilmink et al 1988). A lateral recess height (AP diameter) of 5 mm or • more is normal.…”

“…The average bony AP canal diameter in a group of • individuals without back complaints is 14.4 mm (SD 1.4 mm) at L4 and 14.5 mm (SD 1.9) at L5. The average bony AP canal diameter in a group of patients with back complaints is 14.5 mm (SD 1.4 mm) at L4 and 15.7 mm (SD 2.8) at L5 (Wilmink et al 1988). …”

MRI Techniques in Spinal Imaging

“…This applies to disk protrusion 7,8 but also other degenerative features such as fissuring of the annulus fibrosus and loss of T2 signal of the nucleus pulposus 9 . Major disk pathology such as extrusion and migration, and also signs of nerve root compression, appear to be rare in asymptomatic individuals 8,9 . The sagittal imaging plane is perpendicular to the end-plates and allows best classification of disk condition (normal, bulging, protruded, extruded, migrated).…”