Abstract: A surgical tool guide (100) for minimally invasive preparation of a bony surface to receive an implant comprises at least one contact surface (104, 120) for securely registering the surgical tool guide (100) on a bone (200), and a mechanical guide means (102) configured to restrict movement of a surgical tool (110) received therein such that a working tip (111) of the surgical tool (110), in use, is guided over a predefined area of the bone (200), typically at a pre-planned depth.