Fig. 3From: The effect of robot-navigation-assisted core decompression on early stage osteonecrosis of the femoral headSurgical instruments: robot arm is isolated by the sterile cover, and robot tracker and patient tracker are fixed, respectively, at the distal end of the robot arm and on the patient, guider attaches to the robot arm and firmly holds the sleeve; the sleeve can slide along the guider and invade patientBack to article page