Abstract: An improved hip prosthesis includes an acetabular cup bearing component constructed from a relatively hard and high strength ceramic material for articulation with a ball-shaped femoral head component which may be constructed from a compatible ceramic or metal material. In one form, the acetabular cup further includes a ceramic porous bone ingrowth surface adhered thereto for secure ingrowth attachment to natural patient bone.

Abstract: A prosthetic device made of a first specific type of polyarylene, taken alone or in combination with a second specific type of polyarylene, featuring some unexpected advantages such as a very high strength and stiffness, good elongation properties, high chemical resistance, good biocompatibility as well as an outstanding impact resistance.

Abstract: A prosthetic device, method for planning bone removal, and a robotic system for implantation of a prosthetic device in bone are disclosed. The prosthetic device can include a body portion for attachment to a bone, wherein the body portion includes an implantation surface configured to face the bone upon implantation, and a constraint structure. The prosthetic device, method, and robotic system can be configured to cause the constraint structure and bone to interact so as to constrain the prosthetic device in the bone.

Abstract: The invention provides a multi-polymer hydrogel article having a first polymeric, water-swellable material and a second polymeric material, organized such that a first region substantially comprises the first polymeric, water-swellable material, a second region adjacent the first region comprises a mixture of the first polymeric, water-swellable material and the second polymeric material, and a third region adjacent the second region substantially comprises the second polymeric material. The article exhibits an increasing concentration gradient of the second polymeric material moving from the first region, through the second region, to the third region.

Abstract: Described here is a set for the construction of a resurfacing hip implant. It comprises a thin metal cup for cemented insertion into the natural acetabulum, a thin metal cap for cemented placement upon the natural femoral head, and an inlay which can be placed in the cup of the acetabulum as a sliding partner for the cap for the femoral head. Also described are methods of using and implanting the implant.

Abstract: A prosthetic hip-joint includes: a. a prosthetic acetabulum cup for implantation into a pelvis; b. a prosthetic femoral assembly which includes: i. a ball-shaped femoral head that during implantation becomes located within the cup; and ii. a femoral stem that is fixed at a first end to the head, and that has a second end distal from the first end which is adapted for implant into a medullary canal of a femur, and c. a liner assembly adapted to he secured to the cup and is also adapted to receive and to constrain the head against dislocation. In one aspect the hip-joint permits the head to rotate through an angle which exceeds at least 153 degrees while concurrently constraining the head against dislocation. In another aspect the hip joint constrains the head a dislocation by a preestablished amount of force which is adjustable during implantation thereof.

Abstract: A composition, a medical implant constructed from the composition, and a method of making the composition are described. The composition comprises a porous-coated substrate, the porous coating comprising a reticulated particle coating, the coating being formed by fusing the reticulated particle to the surface, preferably by sintering.

Abstract: A plastic implant device for a mammal that contains a rare earth metal compound tracer and a method for detecting degradation such as wear of the implanted device are disclosed. The tracer can also be present with a separate antioxidant or the tracer compound can be can be the salt of a C6-C22 unsaturated carboxylic acid. The rare earth metal compound tracer is released when the prosthetic is worn down or otherwise degraded in the mammalian body in which it was implanted. The presence and amount of released tracer present in a body fluid or tissue sample measured and is proportional to the degree of degradation of the implant.

Abstract: An assembly including a head and movable neck for preparing the implantation of an artificial hip is described, the head and the movable neck having, respectively, a frustoconical hole and a frustoconical portion insertable therein. The flat end of the frustoconical portion has, coaxially formed or mounted thereon, a cylindrical protrusion having a diameter smaller than that of the frustoconical portion opposite its fiat end and the frustoconical hole has a coaxial, blind, cylindrical extension from the side walls of which an annular protrusion having an internal diameter which produces a slight interference with the diameter of the cylindrical protrusion projects, and the height of the cylindrical extension is greater than or equal to that of the cylindrical protrusion so that, when the latter is inserted over its entire height inside the cylindrical extension, the flat end bears against a concentric shoulder formed on the head around the cylindrical extension.

Abstract: An improved hip prosthesis includes an acetabular cup bearing component constructed from a relatively hard and high strength ceramic material for articulation with a ball-shaped femoral head component which may be constructed from a compatible ceramic or metal material. In one form, the acetabular cup further includes a ceramic porous bone ingrowth surface adhered thereto for secure ingrowth attachment to natural patient bone.

Abstract: Shaped parts of ultra high molecular weight polyethylene (UHMWPE) are made by a process comprising melt processing, wherein a) the UHMWPE has a weight average molecular weight (Mw) of at least 1*106 g/mol, b) during the shaping the storage plateau modulus of the UHMWPE (G*) is kept at a value of at most 1.5 MPa, c) whereafter, before the cooling, the G* is raised to its final value. The shaped parts may advantageously be used in medical applications, e.g., as an element of a hip or knee prosthesis.

Abstract: The invention reduces wear in total joint articulations by modifications of the shape of either component of the kinematic pair, so as to result in an annular surface contact between the two components. Fluid trapped between the two components within the inner contour of the annular contact area is pressurized under load due to elastic deformation of the components and exuded out through inter-articular gap over the surface of contact, aiding in lubrication and reducing the wear. Reduced to practice for a total hip joint with UHMWPE-metal pair, the wear rate tested in a hip joint simulator up to five million cycles was reduced by factor seven to fifteen compared to conventionally shaped components.

Abstract: A metal implant for use in a surgical procedure is provided with a surface layer that is integral with the metal substrate, and which incorporates a biocidal material. The surface layer may be grown from the metal substrate, by anodising, and the biocidal material incorporated in it by ion exchange. Alternatively the layer may be deposited by electroplating, followed by diffusion bonding so as to become integral with the metal substrate. In either case, silver is a suitable biocidal material; and both the release rate and the quantity of biocidal material should be low to avoid toxic effects on body cells. Electropolishing the surface before formation of the surface layer is also beneficial, and this may be achieved by electropolishing.

Abstract: A method for forming an acetabular shell includes providing a working surface such as a mandrel, and spraying the working surface with a first layer of material having a first composition such as aluminum oxide. After a suitable thickness is generated, the spray composition is gradually changed to other compositions having desired particle sizes and distribution. In one example, the composition is changed to a mixture of aluminum oxide and titanium oxide and/or titanium. As thickness builds up, the relative amount of aluminum oxide is decreased such that the composition is all titanium and titanium oxide. After a desired thickness is generated, the acetabular shell is extracted off the mandrel.

Abstract: Apparatus for driving current in a power circuit of a medical device inserted into a body of a subject includes a power transmitter, which is adapted to generate, in a vicinity of the body, an electromagnetic field having a predetermined frequency capable of inductively driving the current in the power circuit. A passive energy transfer amplifier, having a resonant response at the frequency of the electromagnetic field is placed in proximity to the medical device so as to enhance the current driven in the power circuit by the electromagnetic field.

Abstract: A system and method are provided for helping implant a hip prosthesis in an individual, which includes an acetabulum intended to be placed in the hip bone of the patient and a femoral part intended to be integrally connected to the femur of the individual. The method includes: obtaining, before the operation, images issued by a device that images a human body and locates a position of images in space. The images are taken in at least three reference positions: standing; recumbent; and sitting. Before the operation, the method determines a pelvis version of the individual in different positions by analyzing the images. During the operation, the method measures a position of the acetabulum with relation to the pelvis of the individual, and simultaneously restores information representative of prosthetic mobility of the hip with relation to each of the reference positions, for a current position of the acetabulum.

Abstract: A material comprising: from 98-50% by volume of zirconia as a matrix, which is stabilized with i) either of from about 2 to about 3 mole percent of yttria ii) or of from about 10 to about 15 mole percent of ceria; iii) or a mixture of ceria and yttria in the range of amounts as given in i) and ii) the stabilizing oxides may be substituted against each other in a ratio from 1:99 to 99:1 and a maximum stabilization of 3 mole percent related to pure yttria and 15 mole percent related to pure ceria respectively are not exceeded, and wherein the term mole percent is related to the zirconia matrix and wherein the zirconia matrix is obtainable from a) a powder of particles of zirconia having a mean particle size of <0.

Abstract: Highly crystalline, oxidation resistant crosslinked polymeric materials such as crosslinked ultrahigh molecular weight polyethylenes having high wear resistance, enhanced stiffness, enhanced tensile strength, a high level of fatigue and crack propagation resistance, and enhanced creep resistance can be manufactured by the new methods described herein.

Abstract: A prosthetic constraining device for use with a hip replacement prosthesis that includes an acetabular cup assembly adapted to be bonded to a patient's pelvis and a femoral stem adapted to be bonded to the patient's femur, where the femoral stem includes a ball component at its proximal end received within the acetabular cup assembly to form a ball joint type coupling, and where the constraining device includes a ring having a central aperture, where the ring is adapted to be mounted to a rim of the acetabular cup assembly so that the femoral stem passes through the central aperture, where the diameter of the central aperture is less than the diameter of the ball component on the proximal end of the femoral stem so that the ring assists in maintaining the ball joint type coupling between the acetabular cup assembly and the femoral stem, and where the ring comprises a biologic material, a biologically reabsorbable material and a combination of biologic, or biologically reabsorbable materials.

Abstract: A femoral head offset and neck length required in a femoral component to be engaged with an acetabular component are determined for establishing appropriate hip mechanics in a prosthetic hip joint. Alternate selected sleeves of different lengths are interposed between a trial femoral head component and a trial femoral stem component movable relative to one another to admit each selected sleeve, interoperatively, for serial trialing to determine an appropriate trial distance, the appropriate trial distance corresponding to the required femoral head offset and neck length in the prosthetic hip joint.

Abstract: A hip replacement apparatus that normally includes a supporting rod bent into an acute angle at its center with a rounded head on one end. This supporting rod can be received at the pelvis into a pre-assembled housing with a backplate and front plate where the unit can be cemented and/or screwed into the prepared bone at the hip joint. The backplate can have an anchoring protrusion that mates into the trimmed-out bone at the joint. The front plate can have a center hole that receives, and holds the rounded head of the supporting rod from escaping. The head (and hence the supporting rod) freely rotates captively in the housing with the housing firmly attached to the pelvis. The bottom end of the supporting rod can penetrate into the center of the cut-off femur and can be cemented into the bone. The supporting rod can be held to the femur with a bone clamp apparatus including a side plate that can be banded firmly to the femur with one or a more bands.

Abstract: Disclosed is a method of preparing a medical implant. The biocompatible metal surface of the implant is subjected to electrochemical etching in an electrolyte solution to which a current has been applied.

Abstract: A hip joint prosthesis includes connection means for securing the hip joint prosthesis to a securing device and to an artificial leg, and a control unit for controlling an extension movement in the hip joint and for controlling the step length of the artificial leg.

Abstract: The invention concerns article having a surface oxide layer up to 20 nm thick, the surface oxide layer comprising chromium and cobalt oxides where the atomic ratio of Cr/Co is more than 3. The invention also concerns methods for treating a chromium containing material, said method comprising contacting said material with a gas plasma under conditions effective to oxidize at least a portion of the material; and contacting said material with an acid. The treated surface is corrosion resistant and can be used in orthopedic implants, especially the wear surface of the orthopedic implant to reduce wear, and other corrosive environment.

Abstract: A replacement joint for a human body and a method of installing such a replacement joint is provided. A ball portion of the replacement joint is installed on an end of a first bone. A receptacle having an engagement surface that has an aspherical configuration is formed in a second bone. A socket portion of the replacement joint is inserted in the receptacle so as to receive the ball portion on the first bone. The socket portion has an engagement surface with an aspherical configuration complementary to the engagement surface of the receptacle in the second bone. The configurations of the engagement surfaces of the socket portion and the receptacle in the second bone are such that inserting the socket portion in the receptacle in the second bone provides the socket portion with at least four degrees of constraint.

Abstract: A substantially cup-shaped prosthetic device for a joint is provided. The prosthetic device includes an outer surface configured to operatively engage at least one of a first bone of the joint and a component and an inner surface configured to connect to a second bone of the joint. The inner surface is rotationally asymmetric to minimize intrusion on a vascular region of the second bone.

Abstract: A CAS system for measuring surgical parameters during hip replacement surgery comprises a first tracking reference in fixed relation with the pelvis to form a frame of reference. A registration tool is trackable. A sensor apparatus tracks the first tracking reference and the registration tool. A controller unit receives tracking data for the first trackable reference and the registration tool. The controller unit has a position and orientation calculator for calculating from the tracking data a position and orientation of the pelvic tracking reference to track the frame of reference, and of the registration tool to produce femoral models at a first and a second sequential operative steps. An alignment adjustor aligns the femoral models with the frame of reference. A surgical parameter calculator calculates surgical parameters as a function of the femoral models as aligned by the alignment adjustor.

Abstract: A prosthesis and method for a ball and socket joint. The prosthesis includes a first component including an anchoring shank and a metaphyseal portion. The metaphyseal portion includes a first articular surface configured to move in translation relative to the anchoring shank. An intermediate component includes a first articular surface configured to engage with the first articular surface on the metaphyseal portion, and a second articular surface configured to engage with the ball and socket joint.

Abstract: An implantable joint prosthesis configured such that it does not squeak during movements of a subject. The joint prosthesis includes a means to modify the dynamic response of parts of the prosthesis such the response is not audible to the human ear.

Abstract: The present invention provides an irradiated crosslinked polyethylene containing reduced free radicals, preferably containing substantially no residual free radical. Disclosed is a process of making irradiated crosslinked polyethylene by irradiating the polyethylene in contact with a sensitizing environment at an elevated temperature that is below the melting point, in order to reduce the concentration of residual free radicals to an undetectable level. A process of making irradiated crosslinked polyethylene composition having reduced free radical content, preferably containing substantially no residual free radicals, by mechanically deforming the polyethylene at a temperature that is below the melting point of the polyethylene, optionally in a sensitizing environment, is also disclosed herein.

Abstract: An implant having a substantially solid basic structure and a porous jacket structure at least partially enclosing the basic structure for attachment of cellular tissue wherein the basic structure and the jacket structure are connected integrally to each other and the porous jacket structure is formed substantially by a structure with open pores. The disclosure also relates to a method for manufacturing such an implant.

Abstract: A trial prosthetic hip system has a plurality of trial stems each having a recessed bore in a proximal end thereof. At least three sets of trial necks are provided each having a connection element for inserting into the bore in the trial stems. A first set of trial necks having a valgus offset with one of the necks of the first set being anteverted, one be retroverted and one being neutral in version. A second set of trial necks is provided having a varus offset with one neck of the second set being anteverted, one being retroverted and one being neutral in version. A third set of trial necks is provided being neutral in varus-valgus, one neck of the third set being anteverted, one being retroverted and one being anteverted and each trial neck of the first, second and third sets having a coded marking on a proximally facing surface indicating the varus/valgus, anteverted/retroverted and neutral orientations.

Abstract: A prosthetic device having a generally fixed member formed from a low friction material such as ultra-high molecular weight polyethylene and an articulating titanium member, which includes an articular bearing surface. The articular surface is a zirconium oxide layer formed by applying a coating of zirconium onto the titanium member and heating this in an oxygen-containing environment. This causes the zirconium to oxidize and further causes the zirconium to migrate into the titanium member forming a titanium zirconium diffusion layer, which prevents delamination.

Abstract: A hip replacement apparatus that normally includes a supporting rod bent into an acute angle at its center with a rounded head on one end. This supporting rod can be received at the pelvis into a pre-assembled housing with a backplate and front plate where the unit can be cemented and/or screwed into the prepared bone at the hip joint. The backplate can have an anchoring protrusion that mates into the trimmed-out bone at the joint. The front plate can have a center hole that receives, and holds from escaping, the rounded head of the supporting rod. The head (and hence the supporting rod) freely rotates captively in the housing with the housing firmly attached to the pelvis. The bottom end of the supporting rod can penetrate into the center of the cut-off femur and can be cemented into the bone.

Abstract: A prosthetic implant for securing to bone to form an articulating joint is provided. The implant is prepared by a process which includes the steps of preparing a porous surface on a component to form a prosthetic implant, placing the prosthetic implant including the porous surface in a fixture closely conforming to the porous surface of the implant and having an inlet and an opposed outlet, and directing a biological compound including stem cells into the inlet, through the porous surface of the implant and out of the outlet to form a prosthetic implant having a porous surface coated with a portion of the biological compound.

Abstract: Provided is a novel hip replacement implant system that includes a ball assembly having a ball trunion, the ball assembly being configured as a replacement for the head of the femur and capable of being secured by the ball assembly trunion to a calcar implant element that can be securely seated in the calcar bone of the femoral neck, thus maintaining the load transfer function of the calcar bone of the femoral neck. A method of using the device is also provided.

Abstract: A method for arthroplasty includes using a self-locking prosthesis that has a member structured to transfer a load produced by the weight of a patient to a bone. An expandable bone-locking portion that is integral to the member includes a shape-memory material and expands to produce a locking force. A portion of the bone is removed to form an aperture in the bone. The bone-locking portion is inserted into the aperture, and a temperature increase causes a change from a contracted state to an expanded state resulting in expansion of the bone-locking portion so as to contact the inner surface. The expanding is sufficient to create a locking force at the junction between the inner surface and the bone-locking portion of the prosthesis and the majority of the locking force is applied at or above the metaphysis. The length/width ration of the prosthesis may be less than or equal to 5. The resulting reconstructed long-bone may have improved primary and long-term stability.

Abstract: Prosthetic hips are well known in the arts and have been successfully used for many years. There are, however, some inherent health problems associated with present art designs. All of the prosthetic hip designs utilize a variety of materials. Most used are plastic, ceramic and metal materials. One of the main problems associated with prior art prosthetic hips involves friction generated between cup and ball. Friction dislodges, from cup and ball surfaces, plastic, ceramic or metallic fragments during a patient's normal motor functions. These particles interact with the body's chemistry and may cause deleterious health side effects. Rubbing action between cup and ball also produces ions which can adversely affect the patient's health. It is therefore essential that friction between prosthetic hip cup and ball is reduced to a minimum. The design of the prosthetic hip presented herewith will alleviate some of the unwanted friction between cup and ball.

Abstract: A prosthetic joint in which at least one bearing component is made from solid diamond.

Abstract: A composite of polymer or ceramic material has reinforcing fibers. The composite is for use in manufacturing medical implants like osteosynthesis plates, endoprostheses, screw coupling elements, surgical instruments, and similar components. The fibers and fibrous parts are made from a material that absorbs X-rays so that it can be seen during X-ray examination.

Abstract: An orthopedic prosthesis comprising a first component having a soft metal bearing surface and a second component having a hard metal bearing surface, in particular a hip prosthesis comprising a spherical bearing member, a femoral stem, and a modular neck configured for interposition between the spherical bearing member and the stem, together with an acetabular implant having a concave bearing surface configured for articulation with the spherical bearing member. One of the spherical bearing member and the concave bearing surface comprises a soft metal bearing surface, the soft metal bearing surface having a hardness of at least about 20 Rc, while the other one of the spherical bearing member and the concave bearing surface comprises a hard metal bearing surface, the hard metal bearing surface having a hardness greater than the soft metal bearing surface by at least about 15 Rc.

Abstract: A prosthesis for implantation in a femur has a metallic stem portion having a smooth outer surface and a distal tip. A polymethylmethacrylate (PMMA) sleeve surrounds and is in contact with the stem portion. The sleeve has a cavity for receiving the stem tip and a bottom of said cavity spaced from the tip. A metal sheath has a cavity for receiving the sleeve. The metal sheath has a porous outer tissue ingrowth surface and a roughened inner surface. The PMMA sleeve is bonded to the inner surface of the metal sheath with a PMMA bone cement. The stem portion, sleeve and metal sheath all taper inwardly moving from a proximal stem portion to a distal stem portion.

Abstract: A knee implant includes a femoral component having first and second femoral component surfaces. The first femoral component surface is for securing to a surgically prepared compartment of a distal end of a femur. The second femoral component surface is configured to replicate the femoral condyle. The knee implant further includes a tibial component having first and second tibial component surfaces. The first tibial component surface is for contacting a proximal surface of the tibia that is substantially uncut subchondral bone. At least a portion of the first tibial component surface is a mirror image of the proximal tibial surface. The second tibial component surface articulates with the second femoral component surface.

Abstract: A prosthetic joint in which at least one bearing component is made from solid diamond.

Abstract: A first articulating member for use with a second articulating member to form a prosthesis for use in joint arthroplasty for a joint formed between adjacent first and second bones in which a bone fragment having an exterior surface has separated from the first bone is provided. The first articulating member includes an articulating portion having an articulation surface for articulation with the second articulating member and an attaching portion connected to the articulating portion for attachment to the first bone. The first articulating member also includes a fragment portion connected to at least one of the articulating portion and the insertion portion. The fragment portion includes a surface for contact with the external periphery of the bone fragment.

Abstract: A prosthesis for partial replacement of a long bone in humans or animals, the prosthesis including: a proximal or distal end component forming one component of a prosthetic joint; a shaft on or assembled with the distal or proximal end component in use; a stem for engagement in a resected bone; and an initially separate collar assembled to the shaft or an extension thereof in use, the collar being dimensioned to abut the resected end face of the bone into which the prosthesis is to be fitted, wherein the end face of the collar facing the resected face of the bone is sized and shaped to correspond to the resected end face of the bone.

Abstract: A prosthetic hip implant comprising: a neck portion including a prosthetic head mounted thereon; and a stem portion coupled to the neck portion having a generally u-shaped cross-section, the stem curving towards a medial side of a femur on moving in a proximal to distal direction when the stem is implanted, a base portion of the u-shaped cross-section extending between first and second legs of the u-shaped cross-section, the base portion decreasing in thickness while moving in a proximal to distal direction and a length of the first and second legs of the u-shaped cross-section decreasing on moving in a proximal to distal direction.

Abstract: A femoral stem for hip prosthesis is disclosed comprising: a main body with a mainly longitudinal development and a generally wedge shaped, which is inserted into the femoral canal present in the body of the femur; a central body of a generally trapezoidal shape integral with the main body, located in the proximal zone of the femur; an appendix projecting from the central body provided with a terminal pin receiving spherical head of joint into the cotyle belonging to the prosthesis and inserted into the acetubular zone of the pelvic bone. The main body and the central body are defined by a shaped surface on one side and a mixtilinear surface on the opposite side from which a shaped notch is starting involving the central body and extending up to the proximity of the projecting appendix.

Abstract: Tools and methods for implanting hip resurfacing femoral prostheses along a path defined by the axis of a shaped femoral head surface are described. The prostheses are stemless partial ball components having an outer surface shaped to conform to an acetabular socket and may be a two part design having a mating sleeve component with an internal bore adapted to receive the shaped femoral head. The tools and methods are capable of accurately implanting both one and two piece ball components and sleeves without requiring the prosthesis to have a central stem or the preparation of a stem cavity in the femoral head and neck.

Abstract: A hydrocephalus shunt having an anti-inflammatory coating applied to at least the outside surface of the ventricular catheter. Such coatings are also applicable to other medical devices or implants.