Abstract: A surgical instrument system includes a tool (2) including an elongate shaft which defines the tool axis. The shaft bears a plurality of marker rings (10, 11, 12) arranged in a predetermined pattern on the surface of the shaft so that they extend around the shaft axis. The system includes at least two receiving devices (14) which are spaced apart for receiving stereoscopic signals from the rings on the tool, and a data processor (16) for analyzing the signal from the rings and generating information relating to the position and orientation of the tool relative to the receiving device.

Abstract: A computer assisted surgery method and apparatus for determining a change in a property of a joint of a patient caused by an arthroplasty procedure is described. The relative position of a first bone and a second bone of the joint is determined with the joint in a first position. The position of a pre-operative center of motion of the joint relative to the first bone is determined. The position of the second bone relative to the pre-operative center of motion is determined using the relative position of the first and second bones. The position of a post-operative center of motion resulting from a prosthetic component to be used in the joint is determined. The position of the second bone relative to the post-operative center of motion is determined. Any change in the property of the joint. is determined from the difference between the position of the second bone relative to the pre-operative center of motion and the position of the second bone relative to the post-operative center of motion.

Abstract: An alignment guide for guiding the positioning of an acetabular cup implant includes a body having a first end and a second end. A flange extends from the first end and is adapted to rest on a labrum of an acetabulum. At least a first formation is provided at the second end which is adapted to engage with a transverse acetabular ligament of the acetabulum. A formation for accepting a trackable instrument is provided to allow a tracking system to determine the orientation of the guide.

Abstract: A method for producing a customized surgical instrument or prosthesis for a specific patient is described. At least one x-ray image of a body part of the patient is captured. A statistical model having a dense set of anatomical correspondence points across the model is instantiated using image data derived from the at least one x-ray image to generate a patient specific model of the body part having a high accuracy surface. Patient specific data from the patient specific model is used to generate a design of the customized surgical instrument or prosthesis for use in a surgical procedure to be carried out on the body part. The surgical instrument or prosthesis is then manufactured using the design. A computer implemented method for generating the patient specific model of the body part is also described.

Abstract: A planning method and device for knee implants, wherein spatial data on the configuration of a patient's genicular anatomy, in particular of at least a part of the femur and/or the patella and/or the tibia, are captured in order to be inputted into a computer-assisted planning station; the movement of the parts of the genicular anatomy is recorded using a tracking and/or motion capturing method; the captured anatomical and movement data are made available to the computer-assisted planning station; a part of the patient's genicular anatomy is virtually replaced in the planning station by a sample implant and movements of the knee together with the sample implant are simulated; contact and impingement between the non-replaced parts of the genicular anatomy and the implant during the virtual movement is ascertained according to its magnitude; and wherein an adjustment of the positioning, shape or orientation of the implant or of a number of these parameters is determined until the contact and impingement become

Abstract: A method of performing a computer-assisted orthopaedic procedure includes securing a sensor support instrument to the patient's bone. A number of sensors are secured to the support instrument. A computer-assisted orthopaedic surgical instrument is also disclosed.

Abstract: An alignment guide for guiding the positioning of an acetabular cup implant includes a body having a first end and a second end. A flange extends from the first end and is adapted to rest on a labrum of an acetabulum. At least a first formation is provided at the second end which is adapted to engage with a transverse acetabular ligament of the acetabulum. A formation for accepting a trackable instrument is provided to allow a tracking system to determine the orientation of the guide.

Abstract: A computer assisted surgery method and apparatus for determining a change in a property of a joint of a patient caused by an arthroplasty procedure is described. The relative position of a first bone and a second bone of the joint is determined with the joint in a first position. The position of a pre-operative center of motion of the joint relative to the first bone is determined. The position of the second bone relative to the pre-operative center of motion is determined using the relative position of the first and second bones. The position of a post-operative center of motion resulting from a prosthetic component to be used in the joint is determined. The position of the second bone relative to the post-operative center of motion is determined. Any change in the property of the joint. is determined from the difference between the position of the second bone relative to the pre-operative center of motion and the position of the second bone relative to the post-operative center of motion.

Abstract: A method for producing a customised surgical instrument or prosthesis for a specific patient is described. At least one x-ray image of a body part of the patient is captured. A statistical model having a dense set of anatomical correspondence points across the model is instantiated using image data derived from the at least one x-ray image to generate a patient specific model of the body part having a high accuracy surface. Patient specific data from the patient specific model is used to generate a design of the customised surgical instrument or prosthesis for use in a surgical procedure to be carried out on the body part. The surgical instrument or prosthesis is then manufactured using the design. A computer implemented method for generating the patient specific model of the body part is also described.

Abstract: A surgical instrument system includes a tool (2) including an elongate shaft which defines the tool axis. The shaft bears a plurality of marker rings (10, 11, 12) arranged in a predetermined pattern on the surface of the shaft so that they extend around the shaft axis. The system includes at least two receiving devices (14) which are spaced apart for receiving stereoscopic signals from the rings on the tool, and a data processor (16) for analysing the signal from the rings and generating information relating to the position and orientation of the tool relative to the receiving device.

Abstract: A method, apparatus and computer program code for automatically planning at least a part of a surgical procedure to be carried out on a body part of a patient are described. A virtual model of the body part is provided, in which the model has data associated with it representing at least a part of a planned surgical procedure. The virtual model is then morphed to the body part using data derived from the patient's real body part thereby also adapting the part of the planned surgical procedure to reflect the anatomy of the patient's real body part.

Abstract: A method, system and computer program for generating a registered image of a body part of a patient for use in an image guided surgical procedure is described. The method includes attaching a marker detectable by a tracking system to the body part before carrying out surgical steps. The tracking system has a reference frame and the position of the marker in the reference frame is detected. A first image of the body part is captured using an imaging system. An indication of the position of the first image relative to the reference frame of the tracking system is obtained. The first image is then mapped into registration with the position of the body part. The system includes an imaging system for capturing images of the body part. A tracking system detects a marker and determines the position of the marker in the reference frame of the tracking system. A marker is attachable to the body part and detectable by the tracking system.

Abstract: A method of performing a computer-assisted orthopaedic procedure includes securing a sensor support instrument to the patient's bone. A number of sensors are secured to the support instrument. A computer-assisted orthopaedic surgical instrument is also disclosed.

Abstract: A method of performing a computer-assisted orthopaedic procedure includes securing a sensor support instrument to the patient's bone. A number of sensors are secured to the support instrument. A computer-assisted orthopaedic surgical instrument is also disclosed.

Abstract: A surgical instrument system includes a tool (2) including an elongate shaft which defines the tool axis. The shaft bears a plurality of marker rings (10, 11, 12) arranged in a predetermined pattern on the surface of the shaft so that they extend around the shaft axis. The system includes at least two receiving devices (14) which are spaced apart for receiving sterioscopic signals from the rings on the tool, and a data processor (16) for analysing the signal from the rings and generating information relating to the position and orientation of the tool relative to the receiving device.

Abstract: A planning method and device for knee implants, wherein spatial data on the configuration of a patient's genicular anatomy, in particular of at least a part of the femur and/or the patella and/or the tibia, are captured in order to be inputted into a computer-assisted planning station; the movement of the parts of the genicular anatomy is recorded using a tracking and/or motion capturing method; the captured anatomical and movement data are made available to the computer-assisted planning station; a part of the patient's genicular anatomy is virtually replaced in the planning station by a sample implant and movements of the knee together with the sample implant are simulated; contact and impingement between the non-replaced parts of the genicular anatomy and the implant during the virtual movement is ascertained according to its magnitude; and wherein an adjustment of the positioning, shape or orientation of the implant or of a number of these parameters is determined until the contact and impingement become

Abstract: A surgical instrument system includes a tool (2) including an elongate shaft which defines the tool axis. The shaft bears a plurality of marker rings (10, 11, 12) arranged in a predetermined pattern on the surface of the shaft so that they extend around the shaft axis, the marker rings identifying the tool. The system includes a device (14) for receiving signals from the rings, and a data processor (16) for analysing the signal from the rings and generating information relating to the identity of the tool.