1981 Volume 33 Issue 2 Pages 174-201
Using human spinal specimen and myodil as a contrast-medium, the author performed an experimental study. In this expe riment, the space of spinal canal is made narrow at the disco-apophyseal joint level by placing various sizes of silicone rubber material right behind of the intervertebral disc and various types of clay material on the yellow ligament.
Concerning the actual practice of the experiment, the following 3 steps were taken.
In the first experiment, a narrow condition of the spinal canal is created by putting silicone rubber bands or silicone rubber discs of various sizes on the exposed intervertebral disc surfaces at the following 3 different positions as described below.
1) An artificially protruded disc positioned on th e sagittal mid-line (mid-line position)
2) An artificially protruded disc the center of which is positioned at the lat eral border of the spinal dura (lateral line position)
3) An artificially protruded disc positioned between 1 st and 2 nd locations. Thus it is named as the intermediate position. (intermediate position )
4) Thin rectangular shaped silicone rubber band, the size of which is simulated to the superficial posterior intervertebral disc surface is put in place so as to cover the entire posterior surface of the disc.
In the second experiment, a narrow condition of the spinal canal is created by covering under-surface of the yellow ligament with thin layer of clay material of various sizes.
This clay covering is first confined to the interlaminar portion only, second to the capsular portion only, third the covering is on the entire surface of the yellow ligament.
In summerlizing the above, in the first experiment, the spinal canal is made narrow on the disc side only, in the second experiment, on the posterior side (yellow ligament side) only.
And finally in the third experiment, the spinal canal is made narrow under the con dition of combining the 1st and 2nd experiments.
Hence, in this third experi ment, the space encroachment is attained by combining an artificial disc put on the intervertebral disc with various sizes of flat clay material beneath the yellow ligament.
In each of the 3 experiments, the subarachnoidal space is filled with physiological saline solution and 4 cc of myodil, a contrast medium, is diffused with this solution.
Then, X-ray fluoroscopy is done using a technique which is exactly the same as that performed with a real patient.
