Various embodiments of the present invention provide, for example, a system and method for centering a surgical tool about the spinous process or other bony structure. Certain embodiments of the present invention may guide the surgical tool along a posterior midline of the spine in order to divide the spinous process. Various embodiments of the present invention may also further provide a system and method for performing a minimally invasive laminectomy procedure via the midline approach described above that may thus reduce the trauma experienced by tissues surrounding the spine or other bony structure.