Abstract: Arthroplasty devices having improved bone in growth to provide a more secure connection within the body. Different embodiments disclosed include devices having threaded intramedullary components, devices configured to receive bone growth promoting substances, devices with resorbable components, and devices configured to reduce shear stress.

Abstract: A bone plug (61), for blocking of a canal in a bone, has a solid body which by axial compression expands in the radial direction. The height of the body is at most 6 times the average wall thickness of the body. The body (65) is preferably made out of an elastomeric material. For keeping the body (65) axially locked the bone plug comprises a first locking element (67) which is formed by a disc (69) with attached to it a stem (71) provided with saw tooth shaped protrusions (73) which protrudes through an axial opening in the body (65) and a second locking element (75) which is formed by an interrupted ring (77) and an annular plate (79), which are positioned around the stem (71). The ring (77) locks behind one of the protrusions (73) and the annular plate (79) is positioned between the interrupted ring (77) and the body (65). Fixating of the bone plug (61) in the canal is carried out by pushing the interrupted ring (77) along the stem (71) until it locks behind one of the protrusions.

Abstract: In the figures, proximal centering apparatuses (4) for collar-less femur shaft prosthesis (1) which can be cemented in and which can be pushed from the medial onto the shaft (3) in the cemented region are shown. The centering apparatus (4) has at least in the medial region a centering wedge (6) which widens towards the proximal and which is connected via webs (7) to a clamping apparatus (8), with the clamping apparatus (8) being arranged in the cement-less region of the prosthesis neck (2) and being removable when the webs (7) are interrupted.

Abstract: A cartilage plug, which is made from a biocompatible, artificial material, that is used to fill a void in natural cartilage that has been resected due to traumatic injury or chronic disease is disclosed. Alternatively, the plug may be relied upon to anchor a flowable polymer to subchondral bone. The plug is prebricatable in any size, shape, and contour and may be utilized either singly or in a plurality to fill any size void for any application. The plug may be formed of a laminated structure to match the physiological requirements of the repair site. Additionally, ridges may be formed about the periphery of each plug to facilitate its anchoring to surrounding cartilage, bone and/or adjacent plugs.

Abstract: An arthroplasty prosthesis cement restrictor comprises a cylinderlike body having a hexagonal lateral outside cross section. A set of corresponding longitudinal external ridges are disposed along the points of the hexagonal lateral cross section. A spiraling machine-thread is formed in the set of corresponding longitudinal ridges and provides for a threaded positive lock of the cylinderlike body into the walls of a long-bone intramedullary canal. A capped end is disposed at one end of the cylinderlike body and provides for the stoppage of cement injected during arthroplasty into the more distal parts of the intramedullary canal. A number of corresponding longitudinal fenestrations are disposed between the set of corresponding of longitudinal ridges which can be flooded with cement to allow cement contact with the adjacent bone.

Abstract: A prosthesis (10) including a stem (12) for implantation at least partially within the medullary canal (14) of a long bone (16). The prosthesis (10) further includes a rod (20) operably associated with the stem (12) and a centralizer (22) having an opening (24) for receiving at least a portion of the rod (20). The centralizer (22) has a surface (26) for guiding the rod (20) into the opening (24).

Abstract: A plug for stopping the flow of bone cement in a bone channel, such as the intramedullary bone canal, or a previously prepared channel, includes an actuator and a number of flexible beams extending around the bone plug. The actuator is removably attached to a rod within an insertion tool used to deploy the bone plug at a predetermined location within the channel. Within the tool, the rod is pulled to move the actuator into a position applying a compressive force to act between the ends of each of the flexible beams. This compressive force causes each beam to buckle outward, into contact with the channel. The rod is then released from the actuator, and the tool is withrawn from the channel so that bone cement can be applied to hold a prosthesis in place within the channel in a proximal direction from the bone plug.

Abstract: A prosthesis is attached to bone by means of a stem that expands in a bone structure in response to the insertion of a pin.

Abstract: A centralizer for an intramedullary stem of an orthopaedic component that is adapted to be implanted into a medullary canal of a bone includes an annular body having an interior surface and an exterior surface. The centralizer also includes a first exterior fin secured to the exterior surface of the annular body so as to extend outwardly therefrom. The first exterior fin possesses a first length. The centralizer also includes a second exterior fin secured to the exterior surface of the annular body so as to extend outwardly therefrom. The second exterior fin possesses a second length which is greater than the first length. A method of implanting an orthopaedic component into a patient is also disclosed.

Abstract: A keyhole button used as a supplement of a keyhole portion formed on a cranium is constituted to have a brim portion having front and back surfaces, and a shaft portion integrally provided on the back surface of the brim portion. The front surface of the brim portion is convexed in a first direction, and concaved in a second direction that is perpendicular to the first direction.

Abstract: A prosthesis for femur replacement surgery has a stem which is received in the femur. The stem has a blind bore formed at an angle in the upper portion. A modular neck assembly is received in the blind bore. The neck assembly is formed at a desired angle with respect to the vertical axis of the stem. The neck assembly is keyed to the bore to obtain a desired degree of anteversion and offset by a desired rotation of the neck assembly within the bore. A unitary sleeve may be inserted in a canal in the femur to receive the stem and provide circumferential movement of the prosthesis within the femur canal. A porous coating is formed on the outer surface of the stem and the sleeve.

Abstract: A core for forming a bone cement plug for deployment in a bone canal, the core including a base portion defining a bore having internal teeth therein and extending axially and distally from a proximal end of the base portion. A first leg portion depends from and extends distally from the base portion, the first leg portion having a first protrusion at a distal end thereof extending outwardly from an outside wall of the first leg portion through a first arc, and a second leg portion depends from and extends distally from the base portion, the second leg portion having a second protrusion at a distal end thereof extending outwardly from an outside wall of the second leg portion through a second arc and oppositely to the first arc. The toothed bore of the base portion is adapted to receive an expander member to wedge apart the first and second leg portions to expand the core widthwise to secure the core in the bone canal.

Abstract: A plug for insertion into a bone canal is disclosed. The plug comprises an elongate central body of substantially constant cross section carrying at least four radially extending flanges of substantially equal shape and size. The flanges form solid, disk-like structures, free of cuts and are axially spaced along the central axis of the body, such that they extend in substantially parallel planes. The plug is made of a copolymer of a polyalkylene glycol terephthalate and an aromatic polyester.

Abstract: An orthopaedic implant includes a flexible bag having at least a portion thereof which is expandable under pressure; and a polymer within the bag. The orthopaedic implant is implanted within a bone by forming a cavity in the bone; inserting a flexible bag into the cavity, the flexible bag having at least a portion thereof which is expandable under pressure; pressure filling the bag with a polymer, whereby the expandable portion of the bag expands to substantially entirely fill the cavity in the bone; and hardening the polymer.

Abstract: Apparatus and methods are disposed for maintaining the proper positioning of a prosthetic implant having proximal and distal ends within a prepared bone cavity during cement injection and curing. First stabilization means, implantable within the bone cavity, minimize lateral movement of the distal end of the implant, while second stabilization means, physically separate from the means for minimizing lateral movement of the distal end of the implant, minimize both the lateral movement of the proximal end of the implant and the rotational movement of the implant overall. In the preferred embodiment, the second stabilization means includes an apertured cap removably securable to the end of a bone having the prepared cavity through which the implant is inserted and held in place.

Abstract: A plug for stopping the flow of bone cement in a channel within bone, such as the intramedullary bone canal, forming a channel, or a previously prepared channel, includes an actuator and a number of flexible beams extending around the bone plug. The actuator is removably attached to a rod within an insertion tool used to deploy the bone plug at a predetermined location within the channel. Within the tool, the rod is pulled to move the actuator into a position applying a compressive force to act between the ends of each of the flexible beams. This compressive force causes each beam to buckle outward, into contact with the channel. The rod is then released from the actuator, and the tool is withdrawn from the channel so that bone cement can be applied to hold a prosthesis in place within the channel in a proximal direction from the bone plug.

Abstract: In the figures, proximal centering apparatuses (4) for collar-less femur shaft prosthesis (1) which can be cemented in and which can be pushed from the medial onto the shaft (3) in the cemented region are shown. The centering apparatus (4) has at least in the medial region a centering wedge (6) which widens towards the proximal and which is connected via webs (7) to a clamping apparatus (8), with the clamping apparatus (8) being arranged in the cement-less region of the prosthesis neck (2) and being removable when the webs (7) are interrupted.

Abstract: Apparatus and methods are disposed for maintaining the proper positioning of a prosthetic implant having proximal and distal ends within a prepared bone cavity during cement injection and curing. First stabilization means, implantable within the bone cavity, minimize lateral movement of the distal end of the implant, while second stabilization means, physically separate from the means for minimizing lateral movement of the distal end of the implant, minimize both the lateral movement of the proximal end of the implant and the rotational movement of the implant overall. In the preferred embodiment, the second stabilization means includes an apertured cap removably securable to the end of a bone having the prepared cavity through which the implant is inserted and held in place.

Abstract: The figures show a cementable shaft prosthesis (1) comprising a centering apparatus (2) of plastic which can be pushed on at its distal shaft end (3) and which forms a cavity (4) to the distal shaft end (3). Between the distal shaft end (3) and the centering apparatus (2) there exists a clamping connection which enables a deeper sinking in of the shaft end into the cavity in the distal direction. The clamping connection is achieved by a spigot (7) which is formed on at the centering apparatus (2) in the cavity (4) and which protrudes in into a conical bore (5) of the shaft end (3) in the proximal direction.

Abstract: A cement restrictor is provided for creating a fixed obstruction within a bone. An exemplary cement restrictor includes a member or body that is expandable or transitionable from a first diameter to a second diameter.

Abstract: The present invention relates generally to surgical implants intended for the augmentation, repair, and restoration of soft tissue (e.g. gingiva or cartilage), hard tissue (e.g. bone), and the like. More particularly, the present invention relates to the in vivo anchoring of cast implants by stent-like anchors made of a shape memory alloy and/or polymers which are desirably covered with a textile sleeve of a specific porosity.

Abstract: The present invention is an implant for securing to a bone to form a plurality of cement cells. The implant has a bone engagement portion for engagement with the bone. The implant has surfaces defining a first plurality of cement compartments in the bone engagement portion for alignment with a second plurality of cement compartments in the bone to form a plurality of cement cells extending between the implant and the bone when the implant is secured to the bone. The cement cells receive cement therein to form plugs of cement extending between the implant and the bone to secure the implant to the bone.

Abstract: The figures show a cementable shaft prosthesis (1) comprising a centering apparatus (2) of plastic which can be pushed on at its distal shaft end (3) and which forms a cavity (4) to the distal shaft end (3). Between the distal shaft end (3) and the centering apparatus (2) there exists a clamping connection which enables a deeper sinking in of the shaft end into the cavity in the distal direction. The clamping connection is achieved by a spigot (7) which is formed on at the centering apparatus (2) in the cavity (4) and which protrudes in into a conical bore (5) of the shaft end (3) in the proximal direction.

Abstract: A cement restrictor is provided for creating a fixed obstruction within a bone. An exemplary cement restrictor includes a member or body that is expandable or transitionable from a first diameter to a second diameter.

Abstract: A pressurizer device (1) is provided with a body (6) in the form of a collar and a surrounding radially extending flexible flange (8). A prosthetic component to be disposed in a cemented bone cavity is inserted through the central opening (50) in the body (6). Pressure in the bone cement is maintained during insertion of the prosthetic component by the flange (8) being held down around the prosthetic component during insertion.

Abstract: A plug system for preventing material from extruding beyond a desired location in a bone tunnel includes a plug member that has an insertion axis extending from a first end and a plurality of interleaving arms disposed about the insertion axis. The arms are affixed at a second end and are flarable at the first end between an insertion position wherein the arms are relatively close packed and a position wherein the arms are flared. A portion of each arm remains in overlapping relation to an adjacent arm. The system further includes an expansion member that has an insertion portion adapted to separate the arms upon progressive entry along the insertion axis from the first end. In use the plug can be inserted either first end first, with the expansion member drawn into the plug by a manipulator, or second end first, with the expansion member driven along the insertion axis.

Abstract: A centralizer (1) is provided with a hollow body (2) and a plurality of equally spaced arms (4). The arms (4) extend in the form of cup handles from the hollow body (2). Each arm (4) has a variable cross-section along its length with the cross-section becoming increasingly ovoid towards one end of the arm (4).

Abstract: A prosthesis provided with a device for guiding its stem in a bone cavity and in which it is to be attached by cement. The sleeve guiding device comprises a sleeve having an opening to receive the stem and locate the sleeve on the stem at a position at or towards its proximal end. The is dimensioned and adapted to locate the stem in a predetermined position within the cross-sectional area of the bore of the bone cavity.

Abstract: A prosthetic bone material comprising a bonded and sintered product of granules of calcium phosphate compound having a particle size of at least 100 &mgr;m, each of the granules being bonded with particulates of calcium phosphate compound having a particle size of about 1 to 40 &mgr;m, in which the granules are bonded to each other while retaining their original shape, and their bonding strength is a level sufficient to maintain their own shape when the bonded and sintered product is disintegrated, produced by mixing the granules and the particulates, followed by firing the mixture at a temperature of about 800 to 1,200° C.