Patent ID: 8861818

Claim:
A preoperative planning method performed by a computer for hip replacement arthroplasty, the method comprising: an image input step of inputting two-dimensional tomographic images of a patient's lower extremities including a pelvis and a femur; an image reconstruction step of reconstructing a three-dimensional image of the patient's lower extremities including the pelvis and the femur from the two-dimensional tomographic images input at the image input step; a joint prostheses determination step of determining installation positions and installation directions of joint prostheses which are installed in a pelvic acetabulum from the three-dimensional image obtained at the image reconstruction step; a base jig setting step of setting a three-dimensional image of a base jig having three or more columnar supports which abut on three or more reference points of the pelvis with respect to the three-dimensional image obtained at the image reconstruction step; and a parameter acquisition step of acquiring a direction of an indicator which runs through a predetermined position on the base jig in the three-dimensional image of the base jig set at the base jig setting step and becomes parallel to the installation direction of the joint prostheses determined at the joint prostheses determination step.