Patent ID: 8070822

Claim:
A method of ensuring the desired mutual positioning of the main components of a femoral prosthesis during an operation for implantation thereof into a human patient, wherein said femoral prosthesis includes a prosthesis stem with a ball head neck and a cup that is adapted to be in the patient's pelvic cavity, wherein said cup comprises a recess linked with an exterior surface via a side face, in which the prosthesis stem is attached to a femur of the human patient, and the cup is placed on the pelvis of the human, said method comprising: placing a tool on the neck of the prosthesis stem attached to the femur, wherein the tool comprises a guide ball configured for insertion into the recess of the cup and a support selected from the group consisting of an abutment surface and one or more legs, wherein the support is adapted for contact with at least a part of the side face of the cup that links the recess of the cup with the exterior surface of the cup; controlling the mutual angle between the prosthesis stem and the cup with said tool, such that the prosthesis stem and cup are aligned at an optimum mutual angle defined by the contact of the support of the tool with the side face of the cup, wherein the femur that is undergoing surgery is then oriented in a pre-determined position; and placing the cup in its final desired position with the aid of the patient's femur, having said prosthesis stem attached thereto, and the tool placed on the implanted prosthesis stem for controlling the mutual angle between the prosthesis stem and the cup.