A femoral nail which can be implanted in a bone has a transverse hole, and an arrangement is provided for generating a magnetic field which has a maximum strength along an axis of the transverse hole and which decreases in strength in directions radially away from the axis. A drill guide for axially...http://www.google.com/patents/US5584838?utm_source=gb-gplus-sharePatent US5584838 - Distal targeting system
