ABSTRACT
Objective: To observe the decompressive effect of laminectomy on the spinal cord compressed anteriorly in the cervical spine. Methods : The compression of the cervical spinal cord-meningeal complex was simulated using a small transducer pushed into the spinal canal in 7 whole cadaver spines. The depth of canal occlusion was controlled depending on 20%, 30% and 40% of the saggital diameter of the canal. The distribution and the change of the stress on the spinal cord-meningeal complex and the displacement of dural sac were recorded before and after laminectomy. Results: When the anterior transducer was pushed into the spinal canal with 40% occlusion, the force was 3.86 kPa on the anterior wall and 0.38 kPa on the posterior wall of the spinal cord-meningeal complex respectively. After extensive laminectomy, the anterior compressive force decreased 6.06% - 14.38% and the displacement of the posterior dura wall was 0.44 mm. Conclusions: The anterior compressive force was mainly absorbed by the anterior part of the spinal cord-meningeal complex. Extensive laminectomy had no significant decompressive effect on the spinal cord compressed anteriorly inthecervical spine.
ABSTRACT
The lumber ligaments play an important role in spinal bsomechanics. The results of three-dimensional finite element analysis showed that one of functions of lumbar ligaments is transmission of the tensile load between the lumbar vertebrae. The anterior longitudinal ligament is loaded in extension of lumbar spine and the resistance to the tensile load in flexion is provided by other ligaments. These ligaments are subject to much more tension with degsneration of the intervertebral disc so that a series of pathological changes occur. Relevant significance in clinical aspect is also discussed.