Abstract: The present invention relates to a prosthetic knee. In one embodiment of the present invention, the knee has a femoral body and meniscal body. The femoral body has a femoral alignment member, and the meniscal body has a femoral side. Extending from the femoral side are at least two guiding protrusions that extend along the longitudinal axis of the meniscal body and define at least two sides of an alignment groove. The alignment groove slippingly receives the femoral alignment member. The femoral alignment is able to move within the alignment groove and slip over the alignment groove when a force of sufficient magnitude is applied to the prosthetic and revert into the alignment groove. In another embodiment of the present invention, the groove and the alignment components are reversed on the respective femoral and meniscal bodies.

Abstract: A set of femoral orthopedic devices includes a first component having a first size and a second component having a second size. The first component includes a peg positioned a predetermined distance from a first reference point The second component includes a peg positioned said predetermined distance from said first reference point. The method calls for referencing a femoral condyle at a first reference point, locating a peg aperture a predetermined distance from the first reference point, selecting a sized femoral component, and implanting the femoral component. The size of the femoral component is defined by a distance from the peg to a second reference point.

Abstract: A constrained prosthetic knee having a modular hinge post and a rotating bearing. A cannulated hinge post is rotatably connected to the femoral component of the knee prosthesis so that a hinge post extension may be anteriorly positioned through the hinge post and into the tibial component of the knee prosthesis, after positioning of the femoral component in the femur and the tibial component in the tibia. The hinge post is preassembled to the femoral component so that such assembly is not required during the implantation procedure. A meniscal component forming the rotating bearing of the knee prosthesis is packaged together with the hinge post extension so that the appropriate hinge post extension is readily available.

Abstract: The present invention relates to the prevention and decrease of osteolysis produced by wear of the ultrahigh molecular weight polyethylene (UHMWPE). Methods are disclosed for the isolation of wear particles, preparation of implants exhibiting decreased wear in comparison to conventional UHMWPE and preparation of implants that cause decreased biological response in comparison to conventional UHMWPE. The implants created by these methods are also included in the present invention.

Abstract: A generic bone implant, or set of standardized implants, is created based on using a guide device to develop an axis normal to an articular surface of bone and collecting only one or two data points. A generic cutting tool is used to cut the bone to a point where a generic implant can be used. Several improved tools relating to the procedure for using such an implant, as well as methods for using implants consistent with the invention are further described, including: single-axis and biaxial drill guide tools and methods, generic single-axis implant methods and devices, generic biaxial implant methods and devices, tools and methods for holding or delivering an implant, removal or revision tools and methods, digital measuring systems and methods, and set of measuring gauges for determining the appropriate implant dimensions.

Abstract: A modular knee system includes a hinged femoral component and a distal femoral component. A plurality of first stem components are selectively compatible with the hinged femoral component. A plurality of first adaptors are selectively compatible with the first stem components and the distal femoral component. A hinge component is connected to a tibial insert. The hinge component and the tibial insert are selectively compatible with the hinged femoral component and the distal femoral component. A hinged tibial component and a proximal tibial component are selectively compatible with the tibial insert. A plurality of second stem components are selectively compatible with the hinged tibial component. Alternately, a plug component is compatible with the hinged tibial component. A plurality of second adaptors are selectively compatible with the second stem components and the proximal tibial component.

Abstract: Methods and compositions for fabricating prosthetic medical devices exhibiting improved wear resistance include selectively cross-linking polymeric resins then curing and shaping the polymer into a finished article. The selectively cross-linked polymeric compositions may be created by blending a specific amount of cross-linked resins with a specific amount of uncross-linked resins then cured into a polymeric matrix whereby the desired degree or percentage of overall cross-linking is obtained. The polymeric material may then be formed directly into a finished article by injection molding the polymeric material.

Abstract: A mobile bearing knee prosthesis enables a surgeon to convert a mobile bearing insert having articular surfaces, supported by a tibial base plate or tray from a rotating and translating prosthesis to one that rotates only. This conversion is accomplished with a fastener or locking member that connects through an opening in the insert to the tibial base plate. This prosthesis can be used as part of a total knee surgery when the surgeon chooses to use a prosthesis that incorporates a movable articular surface. In one embodiment, a projecting portion extends proximally from the insert and cooperates with a cam on the femoral component. The projecting portion can be a post extending up from the proximal surface of the insert and the femoral component includes an intercondylar surface that may contact the post to constrain the relative motion between the femoral component and the insert.

Abstract: A knee joint prosthesis, comprising at least one femoral component and at least one tibial component. The femoral component having a first portion adapted for fixable attachment to a distal end of a femur and a second portion formed with a bearing surface. The femoral component is sized so as to permit attachment to the femur of a patient without severing at least one the cruciate ligaments. The tibial component has a first surface that is adapted to cooperate with a patient's tibia, while a second surface of the tibial component is adapted to cooperate with the femoral component. The tibial component is sized so as to permit attachment to the patient's tibia without severing at least one of the cruciate ligaments.

Abstract: This invention relates to a floating bearing knee joint prosthesis having a fixed tibial post used for replacing the articulating knee portion of a femur and a tibia. The floating bearing knee joint prosthesis includes a femoral component, a tibial component, a guide post and a bearing member. The femoral component includes an engagement member, a first femoral bearing surface and a second femoral bearing surface. The tibial component includes a tibial bearing surface. The guide post extends from the tibial component and is operable to be engaged by the engagement member of the femoral component. The bearing member includes a first bearing surface that articulates with the first femoral bearing surface, a second bearing surface that articulates with the second femoral bearing surface and a third bearing surface that articulates with the tibial bearing surface.

Abstract: The present invention provides tools and methods for mapping and measuring the articular surface of a joint (or of any bony surface) and for fabricating a prosthetic device based on this recorded data. In one embodiment, once the defect of the chondral surface has been identified, a guide pin is inserted arthroscopically. A fixation screw is driven into the subchondral bone in relation to a reference axis that is approximately central to the defect, the fixation device also serving to define a tangent point to the surrounding articular surface. A further cylindrical proximal extension of the screw that eventually serves as a fixation element for the surface prosthetic is concealed with a cover or plug. The depth positioning of the cover or plug establishes an origin or reference point for all future measuring, cutting, and prosthetic machining operations. A measuring tool having a static post that establishes the axial location of origin is inserted on the reference axis.

Abstract: A method of promoting regeneration of surface cartilage of a joint includes the steps of forming punctures in a subchondral plate of an area of the joint to be treated, covering the puncture and the area to be treated with a chondrocyte-free patch made of a sheet of collagen membrane material without adding chondrocytes to the area to be treated, fixing the patch over the area to be treated, and allowing the area to be treated to regenerate cartilage without adding chondrocytes to the area to be treated.

Abstract: A prosthesis structure (1) for anchorage to the joint end of an articulatory part of a joint (11) in a human or animal body comprises an engagement element (3) which presents a flat or substantially flat engagement surface (3b) for engaging with a complementary joint end surface (14) provided at the joint end and an elongate fixture (4) connected to and spaced from the engagement surface for insertion into a complementary bore (12) provided at the joint end at a distance from the joint end surface (14). The elongate fixture forms an acute angle (&bgr;) with the engagement surface (3b).

Abstract: The invention relates to a replacement knee prosthesis having a femoral component (1) provided with lock pins for attachment to femoral condyls and a plastic tibial component (2) placed in a metal tray (3) fixed to the tibia by means of a pin or a screw. The replacement knee prosthesis is characterized in that the lateral surface of its femoral component (1) has a movement determined by their conical surfaces which is formed in accordance with its logarithmic spiral generatrix (4) while its medial surface corresponds to the conical spiral generatrix (5).

Abstract: A knee joint prosthesis, comprising at least one femoral component and at least one tibial component. The femoral component having a first portion adapted for fixable attachment to a distal end of a femur and a second portion formed with a bearing surface. The femoral component is sized so as to permit attachment to the femur of a patient without severing at least one the cruciate ligaments. The tibial component has a first surface that is adapted to cooperate with a patient's tibia, while a second surface of the tibial component is adapted to cooperate with the femoral component. The tibial component is sized so as to permit attachment to the patient's tibia without severing at least one of the cruciate ligaments.

Abstract: A knee prosthesis which more accurately reproduces the rollback of natural knee movement and, thus, reduces wear on the tibial component. The knee prosthesis includes a femoral component with two cams, the first located between the posterior condylar sections and the second located towards the anterior end of the condylar sections with a slot surface therebetween. The tibial component includes a spine which engages each cam as it rotates along the femoral component and the slot surface during flexion and extension.

Abstract: The present invention discloses a method for enhancing the wear-resistance of polymers by crosslinking them, especially before irradiation sterilization. In particular, this invention presents the use of chemically crosslinked ultrahigh molecular weight polyethylene in in vivo implants.

Abstract: A knee endoprosthesis comprising: a tibial part comprising a tibial rod bearing a tibial plate, a first tibial insert (11) disposed on the tibial plate, a femoral part comprising a femoral rod bearing two condyles (8, 9) each having a first sliding surface co-operating and congruent with a respective second sliding surface formed on the first tibial insert (11), wherein the tibial part is coupled to the femoral part so that the femur can bend relative to the tibia from a position (&agr;≈0) where the knee is extended to a position (&agr;max) where the knee is bent and vice versa. A progressive locking element is provided for limiting the lateral rotation and proper rotation of the condyles (8, 9) relative to the tibial plate, starting from a knee-bending angle &agr;0 determined in advance and up to a zero angle, the amplitude of proper rotation, when the angle &agr;0 is decreased, varying down to zero amplitude (complete blocking) at zero angle (unbent knee).

Abstract: A condylar total knee replacement prosthesis is disclosed having interacting guide surfaces for control of anterior-posterior displacement. The prosthesis comprises a femoral component (1) having a pair of condylar surfaces (2,3), a tibial component having a tibial platform (4) and a bearing component interposed between the femoral and tibial components. A femoral guide surface (5) is located between the condyles and engages with a tibial guide surface (8) to cause the femoral component to displace posteriorly during flexing movements and displace anteriorly during extending movements. The femoral guide surface is offset posteriorly and downwardly from the center of major curvature of the femoral condyles.

Abstract: A tibia part of a knee joint prosthesis includes a tibia platform having a distal side, and an anchoring element. The anchoring element is arranged on the distal side of the tibia platform and attached to the tibia platform. In one embodiment, the anchoring element is formed by a shield having a height which is smaller than a width of the shield, and the shield has a U-, C- or V-shape as seen from the tibia platform.

Abstract: The invention concerns an artificial joint, in particular an endoprosthesis for replacing natural joints, comprising at least two artificial joint parts with curved articulation faces, a curved contact line being formed on each of the articulation faces. The curved contact line (L1) of one of the articulation faces is part of an elliptical section contour of a first cylinder (1) or cone having the cylinder radius (R1) or the cone angle (&agr;1). The other contact line (L2) takes the form of a counter track of a second cylinder (2) or second cone having the cylinder radius (R2) or the cone angle (&agr;2) and rolling and/or sliding on the first cylinder (1) or first cone. The articulation faces comprise control faces (F1, F2) formed from a plurality of straight contact lines (B).

Abstract: A tibia fixturing device comprises a metal tray formed with annularly spaced recesses in its underside at a depth of at least about 1.5 mm and from which a stem depends for axial insertion into a tibia conical cavity. The stem has a circular cylindrical portion proximal the tray and a conical portion distal the tray. Fins radially extend from the stem cylindrical portion and penetrate the tibia to provide some torsional resistance. Axially extending channels are formed about the stem periphery which channels have bottom surfaces parallel to the stem axis to provide further torsional resistance. The channels are arranged to not interlock with the cement in the axial direction to permit the cement to separate first from the device during axial removal of the device from the bone. The fins have inclined edges distal the tray and inclined radial outer edges to align and center the stem to the bone cavity edge.

Abstract: A synovial prosthetic member includes a body having an articulating surface and an anchor surface, the articulating surface being configured for articulation with another articulating surface of a synovial joint, the anchor surface being configured for cementing to bone, the body being composed of ultrahigh molecular weight polyethylene (UHMWPE), the anchor surface having been subjected to treatment by either ion implantation, ion beam assisted deposition, or sputter deposition.

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: An endoprosthesis for replacing at least part of a tibia, includes an elongate shaft extending longitudinally in the direction of a lower leg and having an upper end facing a knee joint and a lower end facing a natural talus. An endoprosthetic knee joint having a tibial plateau is secured to the upper end of the shaft. The talus supports a coupling portion which is connected to the lower end of the shaft.

Abstract: A knee-joint endoprosthesis includes a metallic femoral part (2) anchored in the femur that articulates with a tibial part anchored in the tibia bone, the articulating surface of the femoral part (2) being a ceramic structural member (3) that is connected to the femoral part (2) in a mechanically stable manner. The attachment of the ceramic structural member (3) to the femoral part (2), can be accomplished by using a conical clamping device, by use of a fixing screw, by shrinking, soldering or welding it on, or by vapor deposition or spray application.

Abstract: Knee prosthetic, incorporating a prosthetic femoral component designed to be fixed to the furthest or nearest extremity, of the femur, a tibial prosthetic component designed to be fixed to the nearest or upper extremity of the tibia and at least one intermediary mobile meniscoid prosthetic involving a lower surface working together by sliding with the complementary upper surface of the tibial component, and at least one upper concave surface working together by sliding with a lower condyloid convex surface of the femoral component, characterised by the fact that the upper surface of the tibial component and the lower surface of the meniscoid component are flat and sloped in the same angle from the top at the rear towards the front.

Abstract: An orthopaedic knee component for implanting within a proximal tibia includes a tibial tray with a proximal tibial plateau and a distally extending stem. The tibial tray also includes a recess extending into the tibial plateau. The recess is configured to define a first rotational stop and a second rotational stop. The tibial tray further includes a generally cylindrical post positioned within the recess. The post extends generally orthogonal to the tibial plateau and defines an axis of rotation. A bearing is carried by the tibial tray and has an articular bearing surface for engagement with a femoral component. The bearing has an opening in which the post is disposed. The opening and the post allow pivotal movement of the bearing relative to the tibial plateau about the axis of rotation. The bearing further has a projection extending into the recess of the tibial tray.

Abstract: A method of repairing a damaged joint uses a prosthetic shield and/or spacers to protect regenerating cell growth on the articulating surface of the joint. The shield and spacers protect the articulating surfaces of the joint from compression and frictional stresses while guarding the bone from further damage. The shield and spacers also can deliver transplanted cells and cell enhancing growth factors to the site. The shield can be left in place or removed after the joint heals.

Abstract: Femoral component for a knee prosthesis adapted to cooperate with an insert attached to a tibial plateau anchored at the upper end of a tibia. The femoral component is adapted to be anchored at a lower end of a femur, the femoral component including a first lateral condyle, a second lateral condyle, and an intercondylar space disposed between the first and second condyles for receiving a third removably fixed condyle. The third condyle is removable from the intercondyle space while the femoral component remains moveably engaged with the tibial plateau. The third condyle is adapted to provide posterior stabilization of the prosthesis during flexion between the tibia and the femur when the posterior cruciate ligament is no longer able to substantially perform its function.