Abstract: A CAS system and method for measuring surgical parameters during hip replacement surgery to guide an operator in inserting a hip joint implant in a femur, comprising a first trackable reference in fixed relation with the pelvis and a registration tool. A sensor apparatus tracks the first trackable reference and the registration tool. A controller unit is connected to the sensor apparatus so as to receive tracking data for the first trackable reference and the registration tool. The controller unit has a position and orientation calculator to calculate from the tracking data a position and orientation of the pelvic trackable reference to track the pelvic frame of reference, and of the registration tool to produce a femoral frame of reference at two sequential operative steps.

Abstract: A surgical device adapted for use with an image guided surgical system to facilitate monitoring inter-dependently mobile bone elements. A rigidly connected multiple-point anchor assembly is releasably engageable to at least two inter-dependently mobile bone elements and immobilizes the bone elements such that no relative movement therebetween is possible, and a complex rigid body comprising the immobilized bone elements and the multiple-point anchor assembly is formed. A trackable member is fastened to the multiple-point anchor assembly and comprises a detectable element adapted to be located and tracked in three dimensional space by the image guided surgical system, thereby defining position and movement of the complex rigid body.

Abstract: A hip resurfacing CAS system for guiding an operator in altering a femoral head in computer-assisted surgery for subsequent implanting of a femoral head implant, comprises a trackable reference on the femur. A registration tool is trackable. A bone-altering tool is associated with a resurfacing of the femoral head. A tracking apparatus tracks the tools. A resurfacing processing unit is connected to the tracking apparatus so as to receive tracking data for the tools. The resurfacing processing unit has a position/orientation calculator to calculate from the tracking data a position and orientation of the trackable reference to track the femoral frame of reference, and of the registration tool and the bone-altering tool. A model generator receives position and orientation data of the registration tool to produce a model of the femoral head and neck with respect to the femoral frame of reference.

Abstract: A system for automatic calibration of instruments (S) having varying cross-sectional dimensions within a predetermined range and having detectable elements (110, 112, 113, 114) thereon for computer-aided surgery, comprising a calibration base (C) having detectable elements (43, 44, 46, 48) secured thereto for detecting a position and an orientation thereof in space by sensors (204) connected to a position calculator (202). The calibration base is adapted to receive and to releasably secure a working shaft (100) of any of the instruments (S) and provides an abutting surface (14) for a tip (102) thereof in such a way that a position and orientation of the tip (102) of the instrument (S) secured therein is calculable when working shaft cross-section dimensions thereof are known. The position calculator (202) receives instrument data (214) and calibration data (218) from an operator through a user interface (206) and stores the instrument data (214) and calibration data (218) for subsequent calibrations.

Abstract: A method and an apparatus are described for placing multiple implants during a surgery, the apparatus comprising: a display for an image representing a patient's anatomy; a database of virtual implants from which a user selects; a tool for the user to manipulate in order to select the virtual implants from the database and place the virtual implants in the image at desired locations; and a positioning module for calculating a position of a first of the virtual implants with respect to a second of the virtual implants and allow the user to align the first and second virtual implants with respect to each other, for generating relative position data as a function of the calculated position, and for sending the relative position data to the display.

Abstract: A drill guide assembly for a drilling tool having a chuck engaging a bit portion comprising a tip and a length extending from the chuck, the drill guide assembly comprising a first member, a second member and a trackable member. The first member is adapted to abut a workpiece surface and defines a central aperture therethrough adapted to receive the bit portion of the drilling tool. The second member is adapted to be axially displaced with respect to the first member and is axially biased therefrom, and defines a central aperture therethrough adapted to receive the bit portion of the drilling tool. The trackable member, fastened to the second member, comprises a detectable element adapted to be located and tracked in three dimensional space, thereby defining the position and movement of the second member and therefore that of the bit portion of the drilling tool.

Abstract: A drill guide assembly (10) for a drilling tool (50) having a chuck engaging a bit portion (54) comprising a tip (62) and a length extending from the chuck, the drill guide assembly comprising a first member (14), a second member (12) and a trackable member (16). The first member (14) is adapted to abut a workpiece surface and defines a central aperture (19) therethrough adapted to receive the bit portion. The second member (12) is adapted to be axially displaced with respect to the first member and is axially biased therefrom, and defines a central aperture (11) therethrough adapted to receive the bit portion. The trackable member (16), fastened to the second member, comprises a detectable element (35) adapted to be located and tracked in three dimensional space, thereby defining the position and movement of the second member and therefore that of the drilling tool bit portion.

Abstract: An apparatus for obtaining an axis of an intramedullary canal of an exposed bone with a position tracking system in computer-assisted surgery, comprising a detectable device trackable in space for position and orientation. A stem portion is secured to the detectable device so as to be tracked for position and orientation. The stem portion has a leading end insertable in an intramedullary canal of the bone through an opening in the bone, and is adapted to be handled by a following end thereof. A tip portion is provided at the leading end of the stem portion. The tip portion is positionable in a determined way with respect to a surface of the intramedullary canal, such that reference points with respect to the intramedullary canal are calculable as a function of the position and orientation of the detectable device. The reference points are related to define an axis of the intramedullary canal. A method is provided for digitizing the intramedullary canal axis.

Abstract: A CAS system and method for guiding an operator in inserting a femoral implant in a femur as a function of a limb length and orientation of the femoral implant with respect to the femur, comprising a reference tool for the femur, a registration tool, a bone altering tool and a sensing apparatus.

Abstract: A registration pointer for registering points of surfaces of bodily elements in computer-assisted surgery, comprising a handle for being manipulated by a pointer operator. A stem is connected to the handle and has a first and a second tip configurations each having a respective use relating to a registration of points on specified bodily elements. A detectable device is secured to the stem, and is adapted to be tracked in space for position and orientation by a sensing apparatus. A position of the tip configurations with respect to the detectable device is determinable such that a position of the tip configurations is calculable as a function of the position and orientation of the detectable device. The tip configurations are chosen to register points on given bodily elements as a function of the respective use, by recording a position of points of contact between the tip configurations and the given bodily element.

Abstract: A surgical device adapted for use with an image guided surgical system to facilitate monitoring inter-dependently mobile bone elements. A rigidly connected multiple-point anchor assembly is releasably engageable to at least two inter-dependently mobile bone elements and immobilizes the bone elements such that no relative movement therebetween is possible, and a complex rigid body comprising the immobilized bone elements and the multiple-point anchor assembly is formed. A trackable member is fastened to the multiple-point anchor assembly and comprises a detectable element adapted to be located and tracked in three dimensional space by the image guided surgical system, thereby defining position and movement of the complex rigid body.

Abstract: A system for automatic calibration of instruments (S) having varying cross-sectional dimensions within a predetermined range and having detectable elements (110, 112, 113, 114) thereon for computer-aided surgery, comprising a calibration base (C) having detectable elements (43, 44, 46, 48) secured thereto for detecting a position and an orientation thereof in space by sensors (204) connected to a position calculator (202). The calibration base is adapted to receive and to releasably secure a working shaft (100) of any of the instruments (S) and provides an abutting surface (14) for a tip (102) thereof in such a way that a position and orientation of the tip (102) of the instrument (S) secured therein is calculable when working shaft cross-section dimensions thereof are known. The position calculator (202) receives instrument data (214) and calibration data (218) from an operator through a user interface (206) and stores the instrument data (214) and calibration data (218) for subsequent calibrations.

Abstract: A computer-assisted surgical system and method are described herein. The computer-assisted surgical system comprises a computer including three-dimensional models of anatomical structures and a user interface including a position sensing system to register in real-time the relative positions of the anatomical structures of interest and of a surgical tool. Interactions between the tool and the anatomical structure are displayed on a monitor using the three-dimensional models. Multi-view display, transparency display and use of cutting planes allow the surgeon to visualize the interaction between the tool and the anatomical structures any time during the surgical procedure. The system can also predict the constraint on anatomical structures before surgery.