Relationship among the traumatic spinal canal stenosis,location of conus medullaris,and neurologic deficits in burst fracture of the first lumbar vertebra

Aim: To study the diagnosis and treatment of ependymoma in conus medullaris and cauda equins.

Objective To explore the clinical features and surgical findings of cauda equina and conus medullaris tumors.

A way of calculating the intersecting line of cylinder and cone with the aid of supplementary plane;

Diagraming the characteristic points on the intersection lines between a sphere and a cone by means of the method of anxiliary sphere;

Solution of obliquely intersection-line of cylinder and circular cone;

The Spreading Picture Drawing of the Cylinder and Circular Cone Intersected in the Axial;

The spherical method and auxiliary plane method are usually apply in making up the intersection line, while cylinder and circular cone intersect each other diagonally.

Where taper and column pro-cuts,it usually utilizes characteristic of gather in side elevation to seek the cut line in the furthest right point,passing the top of taper to make cut line of gather circularity,finding out the cutting point in shadow of V side,which was thought that the point should be the furthest right.

It is able to provide a new method for the calculation of furthest right point of taper and column pro-cuts by CAD.