Surgical implant with guiding rail

A method of inserting and positioning a prosthetic intervertebral spacer in an intervertebral disc space between two adjacent vertebrae, the method comprising the steps of:

• providing a spacer including a body having a front end, a rear end, a longitudinal axis, and an interface extending away from the body and being connected to the rear end of the body;
• engaging a tool to the interface;
• forming a hole through only a portion of an annulus fibrosus while leaving the remainder of the annulus fibrosis intact;
• inserting the spacer at least partially into the intervertebral disc space by moving the tool along an axial insertion direction;
• and
• allowing the spacer to rotate with respect to the insertion direction within the intervertebral disc space by allowing the front end to interact with an annulus fibrosus of an intervertebral disc to cause rotation of the spacer with respect to the insertion direction, while continuing to move the tool only along the axial insertion direction, wherein the tool maintains its engagement to the interface during the steps of inserting and allowing.