Notched apparatus for guidance of an insertable instrument along an axis during spinal surgery

A surgical instrument guide for use with a robotic surgical system, the surgical instrument guide comprising a rigid hollow tubular structure having a first open end and a second open end, said structure defining an axis along which movement of a surgical instrument in the structure is restricted, wherein the tubular structure comprises:

• an interior surface shaped and sized to accommodate the surgical instrument in the surgical instrument guide such that movement of the surgical instrument is constrained in at least one direction;
• a longitudinal notch in a side of the rigid hollow tubular structure, wherein the longitudinal notch is sized in relation to a peg to (i) permit a navigation marker attached to the surgical instrument via the peg to be viewable by a navigation camera, and (ii) constrain movement along the axis to a translational range defined by a distance between the lock and the terminal end.