Finally, the Pediguard technique appeared on the market. It is a guide for the perforation of the pedicular channel, with a probe at its extremity. This probe allows a real time measurement of the electric conductivity of the tissues that are being crossed. The conductivity measure is translated in a sound signal. Because the cortical bone has a low conductivity, the probe will emit a low intensity sound signal. The cancellous bone has a medium conductivity. Therefore, the probe will emit a medium sound signal. However, in the event of a breach in the pedicular cortical, as blood and periost have a high conductibility, the probe will emit a intense, rapid pace, sound signal.The Pediguard technique helps thus to anticipate a cortical effraction, by detecting the proximity of the cortical wall. It is efficient but remains relatively expensive.