An apparatus for dictating an insertion trajectory and location for insertion of an elongate pin into a surface includes a primary leg having longitudinally spaced proximal and distal primary leg ends. At least one subordinate leg has longitudinally spaced proximal and distal subordinate leg ends. The proximal subordinate leg end is movably attached to the primary leg by a coupling mechanism allowing at least two degrees of freedom of motion of the subordinate leg relative to the primary leg. The distal subordinate leg end is configured for contact with the surface concurrently with contact of the distal primary leg end with the surface, to support the apparatus during use of the apparatus. The primary leg guides longitudinal translational movement of the elongate pin to insertion into the surface at the dictated insertion trajectory and location when the apparatus is supported in a predetermined guiding relationship with the surface.
