Disc Height Ratio Research Articles

Radiographic evaluation of the lumbosacral disc height

To establish criteria for the radiographic evaluation of narrowing of the L5-S1 disc height, which varies widely with transition of the L5 vertebra. Nondegenerated disc heights of L3-4 to L5-S1 and the thickness and length of the L5 transverse process were measured on plain radiographs of the lumbar spine in 166 outpatients, aged 18-35 years (mean 26.3 years), in whom at least the L3-4 and L5-S1 discs both showed normal signal intensity on magnetic resonance imaging. The level of the iliac crest was recorded semiquantitatively. The disc height was expressed as a percentage of the L3-4 disc height, namely "relative disc height". The ratio of disc height to the sagittal diameter of the overlying vertebral body was termed the "disc height index". The relative disc height and disc height index of L5-S1 showed strong negative correlations with two anatomic variables, which were the relative thickness of the transverse process and the level of the iliac crest (P<0.0001). The results of linear regression analysis suggest that narrowing of the L5-S1 disc height can be evaluated on plain radiographs alone in relation to these anatomic variables.

Carpal tunnel syndrome, humeral epicondylitis, and the cervical spine: a study of clinical and dimensional relations.

Forty-three patients with idiopathic carpal tunnel syndrome, confirmed by nerve conduction studies and treated by surgery, were compared clinically and radiologically with 43 age- and sex-matched control patients. Patients with carpal tunnel syndrome had a significantly greater prevalence of lateral humeral epicondylitis (tennis elbow) (33%) than controls (7%). Randomised reading of the cervical spine radiographs in ignorance of the groups to which they belonged showed no significant difference in the prevalence of either intervertebral disc degeneration or intraforaminal osteophyte protruion using conventional grading methods. Measurement of the minimum anteroposterior diameter of the cervical spinal canal, the anteroposterior diameters of the cervical vertebral bodies, and the ratio of intervertebral disc height to adjacent vertebral body height in the cervical spine, however, showed a consistent trend to smaller measurements in the carpal tunnel group. Differences were significant at several vertebral levels in each of these dimensions. The narrowing of the intervertebral discs relative to the vertebral bodies in patients with carpal tunnel syndrome may indicate connective tissue changes, which might also occur in the common extensor origin at the elbow or in the contents of the carpal tunnel.

DISORDERS OF VOLUNTARY MUSCLE

<h3>ABSTRACT</h3> <h3>Background:</h3> A spinal motion segment comprises facet joints and intervertebral disc. A complex interplay of biomechanical factors occurs between them with degeneration giving rise to numerous pathological conditions. We conducted a study to find a correlation between facet joint orientation and intervertebral discs with age. <h3>Methods:</h3> A cross-sectional study of 203 consecutive subjects undergoing a computed tomography scan of abdomen and pelvis were included. Subjects were divided into 5 groups based on age (group I: 18–30 years; group II: 31–40 years; group III: 41–50 years; group IV: 51–60 years; group V: 61–70 years). Using 3-dimensional reconstruction images, orientation of lumbar facet joints at the L4-5 level was measured. Similarly, adjacent disc heights at L3-4 and L4-5 were measured and their ratio was documented. <h3>Results:</h3> The study included 106 males and 97 females. A positive correlation was noted between age and sagittal facet orientation until age 60 years. However, after age 60 years, a negative correlation with age was seen, which was statistically significant. Similarly, the disc height ratios show a progressive decline in their values with age. However, this decline was statistically significant only after age 60 years. <h3>Conclusion:</h3> The gradual change of facet joint orientation from sagittal to coronal as the age crosses from 30 to 60, to beyond 60, with a simultaneous and parallel diminishing in the disc height probably is one of the attributes of the phenomenon of autostabilization of a motion segment.