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Biomedical subjects

L Y Dai

Publications and source records attributed to L Y Dai.

29 records · Page 2Linked to original sources
PubMed1992

Effects of discectomy on the stress distribution in the lumbar spine.

The change of the stress distribution of the lumbar spine after discectomy was analysed by the three-dimensional finite element method. It was shown that the stress level in the posterior element was higher, but that in the anterior element was lower than before disc excision. The most significant change of the stress distribution was found in the trabecular bone of the vertebral body. It is considered that in discectomy the normal disc tissue should be preserved as much as possible to maintain good function of the spine.

Biomechanical Phenomena↗
PubMed1992

[Comparison of the stress distribution with bone density in the spine].

The results of study on stress distribution of the lumbar spine analyzed with a mechanical model of the lumbar motion segment constructed by a three-dimensional finite element method, and the comparison of resulting values with the corresponding bone density represented by the attenuation value of CT were reported. The results indicated that the stress levels in various parts of the lumbar spine were closely related to the CT values. The authors conclude that the mechanical stress is an important factor in maintaining the dynamic balance of bone growth.

Adult↗
PubMed1991

[Effect of discectomy on the stress distribution in lumbar spine].

The change of stress distribution of lumbar spine after discectomy was analysed with three-dimensional finite element method. It was showed that the stress level in posterior element was elevated, but the stress level in anterior element was lower than before. The most significant change of stress distribution was found in trabecular bone of vertebral bodies. The clinical relevance was discussed.

Biomechanical Phenomena↗
PubMed1991

Influence of flexion-extension motion of lumbar spine on lumbosacral dural sac. An experimental study.

To analyze the effects of flexion-extension motion of lumbar spine on the position and shape of lumbosacral dural sac, 10 flexion/extension lateral myelograms of cadaver specimens of normal lumbar spine were measured. The results showed that moving from flexion to extension both sagittal diameter and length of the dural sac decreased significantly, the dural sac moved caudally, and the sagittal diameter of the anterior epidural space decreased in the mid-vertebral level but increased in the intervertebral level. The dynamic changes of the dural sac and their influence factors and clinical relevance were discussed.

Adult↗
PubMed1989

The effect of flexion-extension motion of the lumbar spine on the capacity of the spinal canal. An experimental study.

The symptoms of lumbar spinal stenosis are often posture-dependent, and it is generally accepted that the capacity of the spinal canal is affected by flexion-extension motions of the lumbar spine. A study of spinal capacity in flexion-extension of ten cadaver specimens on the lumbar spine was done and measurements were obtained from the flexion-extension lateral myelograms. There proved to be a larger capacity of dural sac of 3.5 to 6.0 ml (4.85 +/- 0.75 ml) in flexion than in extension, and the differences were highly significant (P less than 0.001). In addition, the sagittal diameter of the dural sac and the length of the spinal canal increased from extension to flexion. Because of the effect of flexion-extension motion of the lumbar spine on the spinal capacity, we suggest that maintaining the lumbar spine in flexion is more suitable since spinal canal capacity is enlarged and symptoms may be mitigated.

Adult↗