Fig. 4

Schematic diagram of automatic deformation of the hollow pedicle finder. A In this case, the original channel of the pedicle finder was actually not the optimal channel, during the moving process of the pedicle finder, the tip of the pedicle was slightly deformed after touching the cortex, and it automatically entered the good channel instead of directly penetrating out of the cortex. The red line shows that if was the guide needle, due to its sharp tip, the guiding needle will directly penetrate out of the cortex and penetration into the pelvic cavity. B After the hollow pedicle finder automatically entering a good channel due to its slight deformation, we pull out the hollow pedicle finder’s inner core, and then kick into the screw guiding needle, and then pull out the pedicle finder. At last, we screwed the hollow screw directly follow the direction of the guiding needle, the screw entered a good channel