Abstract: A femoral instrument for use in the intramedullary canal is described and includes an intramedullary rod having a tip at a free end. A body is attached to the intramedullary rod and has a face with a bone abutting portion. A centraliser mechanism is located within the rod and is operable to deploy and retract a plurality of members to engage and disengage an inner surface of the intramedullary canal.

Abstract: An instrument for removing tissue from a bone to create a cavity consists of an approximately spherical body having cutting formations in its external surface for cutting a bone. The body has a connector by which it can be connected to a drive by which it can be rotated about an axis, and a recess at the pole, opposite the connector. When the instrument is applied to the surface of a bone and is rotated about its axis, bone is cut as a result of the action of the formations against the bone, and a circular region of bone adjacent to the polar recess in the body remains generally intact.

Abstract: An intramedullary nail assembly comprises an intramedullary nail component (2) al, the nail component having at least one opening (14, 18) in its wall, and a fixation sleeve which has at least one opening (32) extending through it. One of the fixation sleeve and the nail component has a hollow bore so that the other of the sleeve and the nail component can be fitted within it in a coaxial sliding arrangement, with the openings in the wall of the nail component aligned with the openings in the fixation sleeve. A fixation pin (19) is inserted transversely through the openings in the wall of the nail component and the fixation sleeve when the said openings are aligned. An actuator (50) is used to cause the fixation sleeve to move axially relative to the nail component to cause a fixation pin inserted through the aligned openings in the nail component and the fixation sleeve to be gripped.

Abstract: An assembly for use in a hip joint replacement procedure which comprises a stem part for location in the intramedullary cavity of a femur, having a tapered spigot at one end, and a head part having a bearing surface defined by a part of a sphere, and a tapered bore formed in it in which the spigot is a snug fit so that the tapered surfaces of the spigot and the socket are in surface to surface contact. The distance from (i) the point on the tapered surface of the spigot at or towards its free end at which the tapered surface thereof no longer contacts the tapered surface of the bore, to (ii) the centre of the sphere which is defined by the bearing surface measured from the said point on the spigot parallel to the axis of the spigot towards the intramedullary cavity, when the spigot is received in the bore in the head part, is at least about 5 mm, with the said point on the tapered surface of the spigot being located between the centre of the sphere and the bearing surface of the head part.

Abstract: A technique for locating an axis of a bone, which extends through the centre of rotation of the bone around a joint between that bone and another bone, involves a. moving the bone in a plane about the said joint, between a first point and a second point, b. locating a third point which is equidistant from the first and second points, and c. locating the axis which passes through the third point, perpendicular to a line which connects the first and second points. The invention provides an instrument for performing this technique.

Abstract: A cutting guide instrument for use in a cutting step in an orthopedic surgical procedure comprises a reference component comprising a first element which can be attached or otherwise aligned relative to the bone in a predetermined arrangement and a locator arm. The invention further comprises a cutting block comprising a reference surface which can be engaged by a cutting tool to define the location and orientation of the tool during the cutting step. The cutting block further comprises at least one fixation bore for receiving a fixation pin to fix the cutting block to the bone. The locator arm can be fitted against the reference surface so that the reference component and cutting block are arranged in a predetermined manner.

Abstract: A method of monitoring the extent of cure of a mixed bone cement includes the steps of taking in hand a flexible polymeric film wherein loaded with a thermochromic material configured to change color at a predetermined temperature; wrapping a quantity of the mixed bone cement in the film such that the film is in contact with and tightly conforms to the mixed bone cement; and monitoring the film to identify a change in the color of the film, the change in the color of the film indicating that the mixed bone cement has reached the pre-determined temperature.

Abstract: A device for use in the provision of bone cement to a bone cavity of a patient that includes a syringe body, and a tube that communicates with the syringe body. The tube is configured to supply bone cement from within the syringe body to the bone cavity. The tube comprises a polymer loaded with a thermochromic material.

Abstract: End caps and end cap and end plate assemblies for use with a cage or mesh, for use in surgical vertebral fusion procedures are described. A first end cap comprises an annular body and a projection extending from an outer side wall of the body to limit the travel of the end cap into the cage. At least a first and a second flexible member extend from an under side of the body. Each flexible member has a grip on an outer facing surface to retain the end cap on the end of the cage. A second end cap comprises an annular body having an uppermost surface, a projection extending from an outer side wall of the body and a formation adapted to mate with a formation in an end plate, the end plate having a vertebra engaging surface, such that the outermost surface of the body is flush with the vertebra engaging surface of the end plate. When inserted in an end of the cage in use, the projection engages an edge of the cage in more than one location to limit the travel of the end cap into the cage.

Abstract: A cutting tool for preparing a cavity in a bone for receiving a component of an orthopaedic joint prosthesis. The shape of the tool is based on a shell having a rotationally symmetrical outer surface. The tool has at least one portion cut out from it, the cut out portion extending from the peripheral edge of the shell toward the pole of the shell, such that the tool has no more than one plane of symmetry passing through the axis of rotation. The external surface of the shell presents at least two outwardly directed cutting teeth, arranged such that the net translational force on the tool in the plane which is perpendicular to the axis of rotation, resulting from the accumulated resistance of the teeth when rotated against a rotationally symmetrical cavity in which the tool is a snug fit, is approximately balanced.

Abstract: A method of making a component (2) of an orthopaedic joint prosthesis, which has a bearing surface whose shape corresponds approximately to a part of a sphere and is symmetrical about its polar axis, involves use of a cutting tool (6) which has a circular cutting edge (12) and which can be rotated about an axis (8) which is perpendicular to the plane containing the said cutting edge (12). The method involves (a) rotating the component about its polar axis (4) and rotating the cutting tool (6) about its axis (8), with the cutting edge (12) of the cutting tool (6) in contact with the surface of the component (2); (b) moving the cutting tool (i) in a direction parallel to the polar axis (4) of the component (2) while leaving the angle between the axis of the cutting tool (6) and the polar axis of the component (2) unchanged, and (ii) along its axis (8); and (c) repeating step (a).

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 bone resection device (30) for use in resection of bone during joint replacement surgery includes a rotatable shaft (4) having mounted thereon for rotation with the shaft at least two blades (3) carrying at least one cutting edge (3a). The bone resection device (30) further includes a blade positioning mechanism (2) mounted on the device or engaging with the device at least during use thereof and arranged to cooperate with the blades during rotation thereof to alter the orientation of the cutting edge relative to the shaft such that the shape of the resected surface is determined at least in part by the blade positioning mechanism.

Abstract: A combined baling and wrapping apparatus for use in picking up crop material lying on the ground, forming the material into a bale, and applying stretched film wrapping to enclose the bale, said apparatus comprising: a frame; a film reel carrier mounted on the frame to rotate around the bale, said carrier extending at least partly around the bale when seen in plan view; a guide mounted on the frame and defining an orbital path of movement for the carrier around the bale; and, at least one holder for a film dispenser reel mounted on said carrier and rotatable around the bale during rotation of the carrier so that, when a bale has been formed in the chamber and the housing has been moved to the inoperative position, a dispenser reel, when mounted on the carrier, can apply stretch film wrapping to the bale simultaneously with rotation of the bale by the lower bale-forming means.

Abstract: A vertebral-column device that is suitable to be received in an intervertebral space between two dorsal vertebrae, the prosthesis comprising a curved strip of biocompatible material. The width of the strip being such that after placement, the strip makes contact with the vertebrae. The strip is manufactured from a material that can undergo great deformations before permanent deformation arises. The strip is curved in a shape in which the extremities are situated apart from one another and the radius of the curved parts and the thickness of the strip are chosen in such a way that when the strip is bent out into an approximately straight strip, scarcely any permanent deformation arises. Thus, the strip which has been bent out into an approximately straight strip is capable of being introduced into an intervertebral space where the strip assumes its original curved shape.

Abstract: The invention relates to a device for positioning and guiding a surgical instrument during orthopaedic interventions, comprising an industrial robot which has a program-controlled robot arm (1) with several articulated joints and a mounting plate (2) at the end of said arm, an instrument (3) for the orthopaedic intervention attached to the mounting plate (2) and a program control with computer. Sensors for detecting the position of the joints in an instrument-coordinating system defined in the program control are situated in the joints of the robot arm (1). According to the invention, a manually guided sensor device, for example in the form of a sensor arm (4) with multiple joints, is used for the three-dimensional measurement of an object by the instrument-coordinating system of the industrial robot. Using the sensor device (4), and with a previously adopted basic position of the robot arm (1) specified by the program control, reference points can be detected on the bone of the patient.