Occult lumbar lateral spinal stenosis in neural foramina subjected to physiologic loading

Bruce H Nowicki; Victor M Haughton; Timothy A Schmidt; Tae-Hong Lim; Howard S An; Lee H Riley III; Liyuan Yu; Jung-Wha Hong

Occult lumbar lateral spinal stenosis in neural foramina subjected to physiologic loading

Journal article

Peer reviewed

Occult lumbar lateral spinal stenosis in neural foramina subjected to physiologic loading

Bruce H Nowicki, Victor M Haughton, Timothy A Schmidt, Tae-Hong Lim, Howard S An, Lee H Riley III, Liyuan Yu and Jung-Wha Hong

American journal of neuroradiology : AJNR, Vol.17(9), pp.1605-1617

10/1996

PMID: 8896609

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Abstract

To measure the effect of extension, flexion, lateral bending, and axial rotation loads applied to the spine on the anatomic relationship of the spinal nerves in the neural foramen to the ligamentum flavum and the intervertebral disk, anc to determine the effect of disk degeneration on the response to loading. Cadaveric lumbar motion segments were examined with CT and MR imaging, loaded with pure moment forces, frozen in situ, reexamined with CT, and sectioned with a cryomicrotome. The morphology of the intervertebral disks was classified on the basis of the appearance of the cryomicrotome sections. The neural foramina were classified as having no evident stenosis, as being stenotic, as having occult stenosis, or as showing resolved stenosis on the basis of the images and sections before and after loading. The stenotic and nonstenotic foramina were stratified by disk level, intervertebral disk classification, and type of loading applied. The effect of spinal level, disk type, and load type on the prevalence of stenosis was studied. On average, extension, flexion, lateral bending, and axial rotation resulted in the ligamentum flavum or intervertebral disk contacting or compressing the spinal nerve in 18% of the neural foramina. Extension loading produced the most cases of nerve root contact, and lateral bending produced the fewest cases. Each of the loading types resulted also in diminished contact between the spinal nerve and the intervertebral disk or ligamentum flavum in some cases. Disk degeneration significantly increased the prevalence of spinal stenosis. All foramina associated with advanced disk degeneration and half of the foramina associated with disks having radial tears of the annulus fibrosus either developed occult stenosis or were stenotic before loading. The study supports the concept of dynamic spinal stenosis; that is, intermittent stenosis of the neural foramina. Flexion, extension, lateral bending, and axial rotation significantly changed the anatomic relationships of the ligamentum flavum and intervertebral disk to the spinal nerve roots.

Magnetic Resonance Imaging

Adult

Aged

Aged, 80 and over

Biomechanical Phenomena

Female

Humans

Intervertebral Disc - pathology

Intervertebral Disc - physiopathology

Intervertebral Disc Displacement - diagnosis

Intervertebral Disc Displacement - physiopathology

Ligamentum Flavum - pathology

Ligamentum Flavum - physiopathology

Lumbar Vertebrae - pathology

Lumbar Vertebrae - physiopathology

Male

Middle Aged

Nerve Compression Syndromes - diagnosis

Nerve Compression Syndromes - physiopathology

Spinal Nerve Roots - pathology

Spinal Nerve Roots - physiopathology

Spinal Nerves - pathology

Spinal Nerves - physiopathology

Spinal Stenosis - diagnosis

Spinal Stenosis - physiopathology

Tomography, X-Ray Computed

Weight-Bearing - physiology

Details

Title: Subtitle: Occult lumbar lateral spinal stenosis in neural foramina subjected to physiologic loading
Creators: Bruce H Nowicki - Medical College of Wisconsin
Victor M Haughton
Timothy A Schmidt
Tae-Hong Lim
Howard S An
Lee H Riley III
Liyuan Yu
Jung-Wha Hong
Resource Type: Journal article
Publication Details: American journal of neuroradiology : AJNR, Vol.17(9), pp.1605-1617
PMID: 8896609
ISSN: 0195-6108
eISSN: 1936-959X
Grant note: P01 AR33667-08 / NIAMS NIH HHS
Language: English
Date published: 10/1996
Academic Unit: Roy J. Carver Department of Biomedical Engineering
Record Identifier: 9984197130402771

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