請教： thecal sac indentation at C4-C5 level 對於頸椎問題的專業術語是甚麽？

另外下麵這段描述應屬哪種頸椎病？謝謝幫助！

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