Fig. 4
A The physical photos of the laser guiding navigation device. The horizontal red-light laser pointer and the coronal green-light laser pointer were fixed to the G-arm’s image intensifier by the special round strap. The angle of the laser pointer was determined by the position of the two positioning rings. B X-ray fluoroscopy confirmed that the Kirschner wires were inserted in the ideal position by laser. C X-ray fluoroscopy confirmed that the femoral neck cannulated screws were Inserted