Abstract: An osteotomy resection procedure for removing a wedge from a bone utilizing a localization device. The localization device being used to track reference points associated with the bone, track surgical instruments, perform calculations to determine a resection angle for the wedge, and assist a surgeon in performing the procedure.

Abstract: A method and device for preparing an implant from an implant material are provided. A defect image of the defect which has a defect contour is made available, in which a first calibration member arranged in or adjacent to the defect is displayed. A second calibration member is arranged on or adjacent to the implant material to be processed, this second calibration member corresponding to the first calibration member. A real-time image of the implant material is displayed on a display device. The defect image is displayed on the display device and superimposed on the real-time image so that the first and the second calibration members are displayed one on top of the other. A processing tool is displayed on the display device in the real-time image and moved over the implant material so that it follows the defect contour displayed in the defect image.

Abstract: A non-invasive method for determining the articular point of a knee joint is disclosed. The method uses a surgical navigation system having stereoscopic cameras which track the positions of infrared emitting or reflecting markers attached to leg portions on either side of the knee joint. A movable marker is used to palpate known landmarks on the leg portions to determine their positions. The leg portions are moved to determine the trajectories of the landmarks relative to the joint. Positional information from the cameras is fed to a data processing system with resident software which uses the positional information and trajectories to mathematically determine the positions of the knee joint articular point according to the laws of kinematics.

Abstract: A method and device for preparing an implant from an implant material are provided. A defect image of the defect which has a defect contour is made available, in which a first calibration member arranged in or adjacent to the defect is displayed. A second calibration member is arranged on or adjacent to the implant material to be processed, this second calibration member corresponding to the first calibration member. A real-time image of the implant material is displayed on a display device. The defect image is displayed on the display device and superimposed on the real-time image so that the first and the second calibration members are displayed one on top of the other. A processing tool is displayed on the display device in the real-time image and moved over the implant material so that it follows the defect contour displayed in the defect image.

Abstract: To facilitate assistance of the operating surgeon when determining the disposition of a receiving cavity in the case of a method and a navigation system for creating a cavity to receive an acetabulum in a navigated pelvic bone with the aid of a navigated tool, it is proposed that the tear-drop point on the pelvic bone is located by means of a navigated scanning instrument, from the position data and the plane of the pelvic inlet of said pelvic bone there is determined a tear-drop plane, which lies perpendicular to said plane of the pelvic inlet and extends parallel to a line connecting the two anterior superior iliac spines and through the scanned tear-drop point, that a reference point is determined at a defined height above the tear-drop plane and in a defined position in the anterior-posterior direction and at a defined spacing from the outer surface of the pelvic bone in the lateral-medial direction, and that the tool is worked into the pelvic bone in a desired direction relative to the reference point un

Abstract: An osteotomy resection procedure for removing a wedge from a bone utilizing a localization device. The localization device being used to track reference points associated with the bone, track surgical instruments, perform calculations to determine a resection angle for the wedge, and assist a surgeon in performing the procedure.

Abstract: A non-invasive method for determining the articular point of a joint is disclosed. The method uses a surgical navigation system having a stereoscopic cameras which tracks the positions of infrared emitting or reflecting markers attached to appendages on either side of the joint. A movable marker is used to palpate known landmarks on the appendages to determine their positions. The appendages are moved to determine the trajectories of the landmarks relative to the joint. Positional information from the cameras is fed to a data processing system with resident software which uses the positional information and trajectories to mathematically determine the position of the joint articular point according to the laws of kinematics.

Abstract: In a method for determining the orientation and the position of an object in space with the assistance of a sensing instrument which is provided with a marking element and is thereby determinable with respect to its orientation and its position by means of a navigation system, in order to be able to carry out a reliable determination of the position, even under confined conditions of access, it is proposed that the sensing instrument be successively connected in a guided manner to the object for free rotation about two non-parallel, defined axes of rotation, that the sensing instrument be rotated about these axes of rotation, and that the orientation and the position of the two defined axes of rotation in space and hence the orientation and the position of the object in space be calculated from the resulting movement of the marking element during this rotation. A suitable apparatus for carrying out this method and an implant used therein are also described.

Abstract: An osteotomy resection procedure for removing a wedge from a bone utilizing a localization device. The localization device being used to track reference points associated with the bone, track surgical instruments, perform calculations to determine a resection angle for the wedge, and assist a surgeon in performing the procedure.

Abstract: A non-invasive method for determining the articular point of a knee joint is disclosed. The method uses a surgical navigation system having stereoscopic cameras which track the positions of infrared emitting or reflecting markers attached to leg portions on either side of the knee joint. A movable marker is used to palpate known landmarks on the leg portions to determine their positions. The leg portions are moved to determine the trajectories of the landmarks relative to the joint. Positional information from the cameras is fed to a data processing system with resident software which uses the positional information and trajectories to mathematically determine the positions of the knee joint articular point according to the laws of kinematics.

Abstract: A method for determination of the mobility of a hip joint prosthesis is proposed, comprising a bearing cup that can be inserted in the hip bone and a prosthetic shaft that can be inserted in the femur and is pivotally mounted by a spherical joint surface in the bearing cup, which is characterised in that the femur with the prosthetic shaft is pivoted as far as possible in various directions, in that it is determined whether the central point of the bearing cup and the central point of the spherical joint surface move apart from one another during this process, and in that, for each pivoting direction, the maximum pivoting angle is thus determined, at which the central points begin to move apart from one another. A device for carrying out this method is also proposed.

Abstract: The present invention provides methods and apparatus that permit one to position a cutting jig or other component using a localization device to navigate different degrees of freedom of the component in discrete, sequential steps. For instance, a first mounting pin for a cutting jig that sets one or more, but fewer than all, degrees of freedom of the cutting jig is navigated into position using the localization device. For instance, the first mounting pin might set the height and the slope of the cutting plane of the jig. Next, a marker is mounted on the cutting jig and the cutting jig is slid onto the mounted pin. Then the cutting block is navigated in another degree of freedom, for instance, to set the varus-valgus angle of the cutting plane by rotating the jig about the axis of the pin. A second mounting pin for the jig is affixed to the bone based on that navigation.

Abstract: In a method for determining the angle between the femur and the tibia in the implantation of a unicondylar knee prosthesis, in order to determine in advance the influence of the implantation position of the implant on the angle between the femur and the tibia, it is proposed that the position of the unaltered joint surface on the tibia and/or the femur be determined, that the position of a bearing surface for a unicondylar implant on the tibia and/or the femur be determined, and that the angle between the femur and the tibia be calculated using these position data and the geometrical data relating to the unicondylar implant.

Abstract: In order to be able to ascertain the position of the bone in the body without complicated procedures in a process for the preoperative determination of the positioning data of endoprosthetic parts of a central joint relative to the bones forming the central joint, a respective outer articular point is determined by way or movement of the bones about a respective outer joint which is located at the end of the two bones facing away from the central joint. An articular point is determined for each of the two bones in the area of the central joint, and a direction characteristic for each of these bones is determined by way of a straight-line connection of the two articular points obtained in this manner for the two bones. The orientation of the endoprosthetic parts relative to this characteristic direction is then determined. Apparatus for carrying out the process is also provided.

Abstract: To be able to determine the insertion position of the parts of an artificial knee joint without changing the original knee joint, a method is proposed for determining the position of the tibial part and/or the femoral part of a knee-joint endoprosthesis in relation to the proximal tibial head or to the distal femur in which the position of the femur and of the tibia are monitored by means of a navigation system, in which the distal femur and the proximal tibial head are laterally and medially displaced with a defined force into a spread position by means of a distraction appliance when the knee is straightened and bent, and the relative positions of the femur and the tibia, and consequently the size of the gap between the femur and the tibia, are thereby respectively determined, in which various virtual relative positions of the femur and the tibia are calculated according to geometrical data of the knee-joint endoprosthesis and to different assumed positions of the tibial part on the tibia and/or of the femo

Abstract: In order to establish an optimum position on the upper side of the tibia for the exit point of an anterior cruciate ligament replacement, it is proposed that, with the leg bent, the position of a number of points along the front edge of the notch is detected and in this way their position and progression on the femur are also determined, that, with the leg straight, the course of this front edge of the notch is projected onto a projection plane which is perpendicular to the longitudinal axis of the tibia in the region of the upper side of the tibia, and that, within the region enclosed by this projected curve, the exit point is selected such that it maintains at least a distance corresponding to the radius of the implant from the projected curve. Furthermore, an apparatus for carrying out such a method is proposed.

Abstract: In order to be able to ascertain the position of the bone in the body without complicated procedures in a process for the preoperative determination of the positioning data of endoprosthetic parts of a central joint relative to the bones forming the central joint, a respective outer articular point is determined by way of movement of the bones about a respective outer joint which is located at the end of the two bones facing away from the central joint. An articular point is determined for each of the two bones in the area of the central joint, and a direction characteristic for each of these bones is determined by way of a straight-line connection of the two articular points obtained in this manner for the two bones. The orientation of the endoprosthetic parts relative to this characteristic direction is then determined. Apparatus for carrying out the process is also provided.

Abstract: To make available a method for checking a marking element for displacement in relation to a holding structure, in particular a bone, on which this marking element is fixed, said marking element being used for determining position in navigational surgery, and said marking element functioning with the greatest possible precision, it is proposed to choose a point of orientation which is in a unique relationship to the holding structure and to monitor the position of the point of orientation in a reference system of the marking element.

Abstract: A method and apparatus for cross checking points palpated with a localization device. Points corresponding to the palpated points are obtained from a preoperative image of an object such as an X-Ray of a tibia bone. During a surgical procedure, the accuracy of palpated points are determined based on the palpated points and corresponding points obtained from the preoperative image. If a palpated point is inaccurate, an indicator is generated to indicate the inaccuracy of the palpated point.

Abstract: In order to be able to ascertain the position of the bone in the body without complicated procedures in a process for the preoperative determination of the positioning data of endoprosthetic parts of a central joint relative to the bones forming the central joint, a respective outer articular point is determined by way or movement of the bones about a respective outer joint which is located at the end of the two bones facing away from the central joint. An articular point is determined for each of the two bones in the area of the central joint, and a direction characteristic for each of these bones is determined by way of a straight-line connection of the two articular points obtained in this manner for the two bones. The orientation of the endoprosthetic parts relative to this characteristic direction is then determined. Apparatus for carrying out the process is also provided.