请教： thecal sac indentation at C4-C5 level 对于颈椎问题的专业术语是甚麽？

另外下面这段描述应属哪种颈椎病？谢谢帮助！

Posterior disc-ridge complex centrally and bilaterally with indentation of the spinal cord centrally and rifge encrachment more on the leftside with indentation of left C6 nerve root and marked stenosis of the leftneural foramen at C5-6 level