The collar 103 will be resorbed and thereafter the flexible disc 102 will function in a flexible manner between the vertebrae. [0068] Referring to the drawings, and particularly to the embodiment of the invention shown in FIGS. 1 and 4, the prosthesis or implant of the present invention comprises a cage 1 having a pair of upper and lower sections 2 and 3 which are identical to and complimentary to