Gravity dependent pedicle screw tap hole guide

A gravity dependent pedicle screw tap hole guide, comprising:

• a guide shaft having a proximal end, a distal end, and a longitudinal axis, the guide shaft being maintainable parallel to a drill bit during the drilling of a pedicle screw tap hole with the drill bit;
• a level indicator associated with a reference direction and being responsive to gravity to provide feedback regarding an angular difference between an acting direction of gravity and the reference direction;
• and
• a mounting by which the level indicator is attached to the guide shaft, the mounting establishing a positional relationship between the reference direction and the longitudinal axis of the guide shaft;
• wherein the level indicator comprises a fluid chamber that is partially filled with fluid such that a gas bubble is free to move in the fluid chamber through a plurality of positions including a position at which the reference direction is parallel to the acting direction of gravity and a plurality of positions at which the reference direction is angulated with respect to the acting direction of gravity, the fluid chamber having a wall through which the gas bubble is visible, the wall having a reference mark indicating the parallel position.