Stress in lumbar intervertebral discs during distraction: a cadaveric study

Abstract

BACKGROUND CONTEXT-The intervertebral disc is a common source of low back pain. Prospective studies suggest that treatments that intermittently distract the disc might be beneficial for chronic low back pain. Although the potential exists for distraction therapies to affect the disc biomechanically their effect on intradiscal stress is debated.

The Effects of Manual Therapy Using Joint Mobilization and Flexion-distraction Techniques on Chronic Low Back Pain and Disc Heights

“…Gay et al 15. ) reported distraction techniques performed on 15 dead bodies, and measurements of nucleus pulposus pressure and annulus fibrosus compressive stress indicated a pressure decrease in the intervertebral disc of 99% using distraction techniques, 73% using extension-distraction techniques, and 65% using flexion-distraction techniques.…”

The internal mechanical functioning of intervertebral discs and articular cartilage, and its relevance to matrix biology

“…Engineers and physicists (including the present authors) remain unsure about what exactly is being measured in stress profilometry, but extensive validation studies have placed strict bounds on the uncertainty, and similar techniques are being adopted by other groups (Edwards et al, 2001;Steffen et al, 1998;Gay et al, 2008). Limitations of the technique include its spatial resolution, which is determined by transducer size (2 mm), and its inability to detect tensile and shear stresses.…”

Reduction in Disk and Fiber Stresses by Axial Distraction is Higher in Cervical Disk With Fibers Oriented Toward the Vertical Rather Than Horizontal Plane: A Finite Element Model Analysis

“…19 These stress patterns are not same as in the lumbar disks, in which the posteriorlateral AF is stressed more than the anterior AF. 17,18,44 The reason for differences between regional stress patterns in cervical and lumbar disks may be because of differences in an eccentric AP position of NP, which has a large contribution to disk compressive hydrostatic properties. The NP in a cervical disk covers about 38% of the disk AP diameter and is oriented more toward the posterior than the anterior disk.…”

“…[13][14][15] Radiculopathy and herniated or prolapsed disks have been effectively treated with distraction therapies. [16][17][18][19][20] Past research indicates that the application of distraction forces causes a decrease in the area of the protruded disk and an expansion of the posterior disk space. 13 However, there still is not a clear understanding as to how these 2 different vector forces in the axial direction (distraction and compression) change the load-sharing mechanics between disk fibers and the surrounding disk matrix-these poorly explained mechanisms in the literature form the basis for the current study hypothesis.…”