Abstract: Joint replacement spacers that fully seat against the cut surface of a bone while remaining free to move on the cut surface within prescribed limits; methods of joint replacement using such spacers.

Abstract: An elongate, longitudinally oriented outer sleeve includes an outer sleeve surface defining a radially oriented proximal sleeve border, a radially oriented proximal sleeve rim intersecting the outer sleeve surface at the proximal sleeve border, an outer sleeve body enclosed by the outer sleeve surface and the proximal sleeve rim, and an elongate, longitudinally oriented stem-receiving cavity formed in the outer sleeve body and intersecting the proximal sleeve rim to define a stem-receiving aperture. A joint articulating member includes an elongate, longitudinally oriented stem, an articulating surface, and an interface rim. When the stem is at least partially inserted into the stem-receiving cavity, the proximal sleeve rim and the interface rim interact to change a longitudinal relationship between the outer sleeve and the joint articulating member responsive to relative radially-oriented rotation between the stem and the stem-receiving cavity.

Abstract: A medical implant interposable between a first bone and a second bone in order to support the first and second bones substantially joined one to the other, so as to obtain bony fusion of the first and second bones. Also disclosed is a surgical kit comprising an implant and a surgical instrument for bony preparation. Also disclosed is a method for manufacturing a medical implant.

Abstract: An implant for the trapezium of the thumb carpometacarpal (CMC) joint comprising an integral elastomeric member configured to include a body portion having a tapered neck, having extending from one end thereof an elongated, longitudinally extending tapered portion adapted to be embedded into a reamed out-channel in the thumb metacarpal bone. After implantation, in the preferred embodiment of the method according to the invention, a segment of a nearby tendon, for example, the APL or FCR tendons, may be wrapped around the tapered neck of the implant to secure it in position, thereby forming a reinforced structure to inhibit dislocation of the prosthesis. However, in other methods, various other securing elements, including, but not limited to acellular matrices, may be used to retain the implant in position.

Abstract: The invention relates to a hinge comprising a first rigid body, a second rigid body and a joint member connected to the first rigid body and the second rigid body allowing substantially two-dimensional rotation of the first rigid body and the second and rigid body relative to each other. The joint member comprises HPPE fibers which are bendable by the rotation.

Abstract: An arthroplastic implant for a basilar joint of a hand of a patient includes a body having a distal surface and a proximal surface opposite therefrom. The distal surface is to be positioned adjacent a first metacarpal bone at the basilar joint of the hand of the patient. The arthroplastic implant also includes a shield extending outwardly from the distal surface of the body to shield adjacent portions of the first metacarpal bone and a second metacarpal bone of the hand of the patient.

Abstract: Thumb carpometacarpal (CMC) joint implants include a trapezium implant defining an articulating surface and a cooperating first metacarpal implant with a base portion of the first metacarpal defining an articulating surface. The first metacarpal base articulating-surface is configured to articulate against the trapezium implant articulating surface.

Abstract: Generally, an intra-osseous fusion system which provides an implantable intra-osseous member and a method of implanting the intra-osseous member for bone on growth which retains an amount of digit curvature.

Abstract: In a finger joint prosthesis comprising a joint body 14 having first and second joint elements which are connected together pivotably about an axis of rotation and from which a respective anchoring bar 30, 32 extends for securing to a proximal and/or distal phalanx, wherein the anchoring bars 30, 32 can have one or more securing eyes 40, 42, 44 with openings for receiving fixing screws. To provide improved primary and secondary fixing it is proposed that an end securing element is provided distally from the axis of rotation on the anchoring bar 30, 32 of at least one joint element.

Abstract: A system, devices and methods for performing an osteotomy on a bone of a multi-axis joint are provided. A cutting guide system is provided for performing one or more cuts to the bone, using the articular surfaces of the articulating bones as a reference. If desired, a prosthesis can be used to emulate the osteotomy and substitute for a damaged articular surface of a bone of a multiaxis joint.

Abstract: An orthopaedic implant (2) used in arthroplasty of the fingers comprises a first element (3) for a proximal phalanx (4) and a second element (5) for an adjacent distal phalanx (6), each element having a respective stem (7, 8) for implantation in the bone and an interphalangeal articulation head (9, 10), the head (9) of the first element having a biconvex surface (11) of articulation, with a central valley (12), and the head (10) of the second element having a biconcave surface (13) of articulation designed to cooperate with said convex surface and comprising a central crest (14). At rest, the surfaces (11, 13) are congruent in the frontal plane of the articulation in the area of the condyles and non-congruent in the sagittal plane.

Abstract: Basal thumb joint implant has a head with a smooth, generally hemispherical, medio-proximally directed, articulating surface, and a generally abrupt, distally directed, truncation thereto; and a stem attached to the head, which arises from the truncation of the head and includes at least one of the following features: A) a general angle of attachment to the head which is acute in relation to the truncation of the head; B) a flanged cross-sectional stem profile; C) an inwardly curved stem; D) an eccentric head attachment site for the stem. The implant may be one-piece or modular in construction.

Abstract: A modular proximal interphalangeal joint implant assembly including a first stem component, a second stem component, and an articulation assembly. The first stem component includes a first locking device and is operable to be implanted in a proximal phalanx bone. The second stem component includes a second locking device and is operable to be implanted in a middle phalanx bone. The articulation assembly includes a first articulation component operable to be removably attached to the first locking device and a second articulation component operable to be removably attached to the second locking device. The articulation assembly can include a semi-constrained articulation assembly or a constrained articulation assembly.

Abstract: A hemi-arthroplasty implant (11) joint replacement for the base of the first metacarpal of the CMC joint is created which can effectively restore and reestablish functional joint mechanics. The implant (11) has a unique head section (13) creating a particular interrelation between a spherical head articular surface (19), that is received in a surgically prepared cavity in the trapezium, wherein a supporting neck (21) in a re-entrant region joins the head to a flat, generally oblong collar (15).

Abstract: The present invention relates to a joint prosthesis (1) comprising two prosthesis components (2, 3) intended to be applied respectively to the trapezium (38) and the first metacarpal bone (39) of a thumb joint, each prosthesis component having a first or second screw-like part (4, 5) intended to be screwed firmly or be fastened to one of said bones (38 or 39) by means of bone cement, the one prosthesis component (2) having an articulating socket element (6) and the other prosthesis component (3) an articulating ball element (7). The fact that at least the prosthesis component (2) with the socket element (6) has an abutment portion (20) for abutment against the bone to which the screw-like part (4) of the prosthesis component is intended to be firmly screwed or be fastened by means of bone cement, normally the trapezium (38), prevents this prosthesis component from sinking into said bone.

Abstract: Thumb carpometacarpal (CMC) joint implants include a trapezium implant defining an articulating surface and a cooperating first metacarpal implant with a base portion of the first metacarpal defining an articulating surface. The first metacarpal base articulating-surface is configured to articulate against the trapezium implant articulating surface.

Abstract: The present invention relates to methods for making oxidation resistant medical devices that comprise polymeric materials, for example, ultra-high molecular weight polyethylene (UHMWPE). The invention also provides methods of making antioxidant-doped medical implants, for example, doping of medical devices containing cross-linked UHMWPE with vitamin E by diffusion and materials used therein.

Abstract: An implantable replacement joint includes first and second components having respective bores, and a flexible member within a cavity formed by the respective bores.

Abstract: An interpositional biarticular disk implant (11) having a circular peripheral rim, a generally toroidal axial center opening (13) and convex upper and lower surfaces (15, 17) is implanted between resected concave surfaces of the metacarpal base and the trapezium or other carpal bone in a CMC joint replacement. The disk (11) is anchored in operative position through the use of a flexible cord, such as a harvested tendon that passes through the center opening (13) and through osseous passageways created in the two facing bones.

Abstract: The invention relates to a system which is used to replace ball bone joints. The inventive system consists of: a bone anchoring shell (1) comprising a smooth articular surface (7) on the inner concave face thereof; a prosthesis (5) comprising a polished ball (4) and a neck (6) which is characterised in that it is smooth and slightly flared, in order to enable a wear-free low friction movement; and a mobile articular cup (3) which slides (i) on the ball (4) and the neck (6) of a prosthesis (5) and (ii) in the smooth cavity (7) of the bone anchoring shell (1) and which is characterised in that the opening (8) in said cup (3) tapers towards the center thereof, with an inside diameter (9) of equal to or less than that of the ball (4), such that the flared part adapts perfectly to the flared neck (6) in all of the respective positions of the mobile parts.

Abstract: The invention relates to a prosthetic finger (1) with a proximal member (10), a medial member (20) and a distal member (30) that are mounted pivotably on one another, and with a motor (40) which is arranged in the prosthetic finger (1) and which, via a gear mechanism, rotates the medial member (20) relative to the proximal member (10), said medial member (20) accommodating a longitudinally movable balance arm (90) which is connected via levers (91, 93) to the proximal member (10) and to the distal member (30).

Abstract: The invention relates to a joint part prosthesis, particularly for a finger joint, consisting either of a proximal or a distal component as well as a shaft extending away from this component, to be mounted in a bone. The invention provides that the shaft (4) is at least partially formed as an expansion sleeve (7).

Abstract: The invention relates to a joint part prosthesis, particularly for a finger joint, consisting of either a proximal or a distal component, as well as a shaft that extends away from this component, to be mounted in a bone, which shaft is configured with a fin-like anti-twist device. According to the invention, it is provided that as an anti-twist device (7), at least two anti-twist elements (8) are disposed on the mantle surface (6) of the shaft (4), with rotation symmetry, and extend radially away from this mantle surface (6) and in the longitudinal direction of the shaft (4), whereby the distance of the anti-twist elements (8) from the mantle surface (6) decreases slightly in the direction toward the free end (5) of the shaft (4).

Abstract: The concepts disclosed herein offer a new simple and reliable reconstructive option for the treatment of first carpal-metacarpal joint (basal joint) arthritis and consists of an intra-articular basal joint stabilizer sling combined with a surgical method of implantation.

Abstract: A finger joint prosthesis is provided including a joint body having first and second joint elements, which are connected together pivotably about a rotary axis and from each of which extends an anchoring bar for fixing to a proximal and/or distal phalanx. The anchoring bars have eyes with openings for receiving fixing screws. To increase stability, it is proposed that the first joint element have an external hollow body with an insertion opening that the second joint element have an internal hollow body, and that the internal hollow body in the position of installation can be inserted by way of the insertion opening relatively movably into the external hollow body. A spindle can be inserted in the position of installation into the internal hollow body for rotationally movable connection to the external hollow body.

Abstract: An arthrodesis implant is for a finger joint of a hand of a patient. The arthrodesis implant may include an extramedullary proximal anchor including a first member having a fastener-receiving passageway therethrough to receive a fastener to anchor the first member to an extramedullary portion of a proximal bone of the finger joint of the hand of the patient. The arthrodesis implant may also include an intramedullary distal anchor having a second member for being anchored within an intramedullary portion of a distal bone of the finger joint of the hand of the patient, and a coupling for securing the first and second members together.

Abstract: An arthroplastic implant is for a basilar joint of a hand of a patient. The arthroplastic implant may include a body having a distal surface and a proximal surface opposite therefrom with the distal surface to be positioned adjacent a first metacarpal bone at the basilar joint of the hand of the patient. The arthroplastic implant may also include an anchor peg extending outwardly from the body to anchor the body within the basilar joint of the hand of the patient.

Abstract: An arthroplastic implant for a basilar joint of a hand of a patient includes a body having a distal surface and a proximal surface opposite therefrom. The distal surface is to be positioned adjacent a first metacarpal bone at the basilar joint of the hand of the patient. The arthroplastic implant also includes a shield extending outwardly from the distal surface of the body to shield adjacent portions of the first metacarpal bone and a second metacarpal bone of the hand of the patient.

Abstract: This present invention concerns a trapezian or trapezo-metacarpal implant (1) that includes a rod (2) and a head (3) that are respectively intended to be inserted into the metacarpus (4) of the thumb, and to be anchored in a space that is created in particular by removing at least a portion of the trapezius (5). According to the invention, the rod (2) and the head (3) of the implant are independent of each other, and are designed to fit together with each other at least at one end (2a) of the rod, through the use of complementary connecting means (6, 34) allowing movement of the head with at least one degree of freedom in rotation, in relation to the rod and the said head (3), including rotation means (32) in the said space obtained by removing at least a portion of the trapezius (5).

Abstract: Hemi joint replacements for the base of the first metacarpal of the CMC joint are provided which can effectively restore and reestablish functional joint mechanics while preserving the soft tissues that contribute to joint stability and function. The implants have a unique head shape with a saddle-like articular surface that is shaped somewhat similar to a conventional bicycle seat. A set of four proportionately larger and smaller implants allows a surgeon to choose the appropriately sized prosthesis for implantation in respect of the metacarpal osteotomy.

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: Thumb carpometacarpal (CMC) joint implants include a trapezium implant defining an articulating surface and a cooperating first metacarpal implant with a base portion of the first metacarpal defining an articulating surface. The first metacarpal base articulating-surface is configured to articulate against the trapezium implant articulating surface.

Abstract: A distal component for an interphalangeal prosthesis suitable for insertion into a proximal end of a distal phalangeal bone includes a stem portion shaped to be received within a surgically prepared bore in the proximal end of the distal bone. A head portion has an under-surface and an upper-surface, the under-surface of which in use will bear on the bone into which the stem is implanted.

Abstract: A prosthetic finger includes a crossed four (4) bar linkage system having a base formed by a base bar, two cross bars, and an interface bar that engages an object to be held. The base bar is fixed to an artificial finger of an amputee. A first cross bar has a first end pivotally mounted to a first end of the base bar and a second cross bar has a first end pivotally mounted to a second end of the base bar. The first cross bar has a second end pivotally mounted to a first end of the interface bar and the second cross bar has a second end pivotally mounted to a second end of the interface bar. The first and second cross bars are slideably interconnected to one another at a cross point which changes its location as the prosthesis grasps objects of differing sizes and shapes.

Abstract: A prosthetic medical device exhibiting improved wear resistance is fabricated by sealing at least one polyolefinic material in an airtight container and providing an inert atmosphere within the airtight container. The polyolefinic material is exposed to an irradiation source to yield a cross-linked irradiated polyolefinic material. At least one non-irradiated polyolefinic material is blended with the irradiated polyolefinic material, and the prosthetic medical device is formed from the blended material. 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: The implant includes a stem terminating in a head. The stem is adapted to be inserted in the metacarpus of the thumb and the head to be disposed in a space obtained particularly by removing at least a portion of the trapezium. The surface of the head is constituted by a base connected to the stem and adapted to rest on the proximal end of the metacarpus, a distal surface portion opposite the base and serving as a contact surface with the bone located facing the proximal end of the metacarpus, and a connecting portion connecting the base and the distal surface portion of the head. The distal surface portion of the head is inclined relative to a longitudinal axis of the stem by a predetermined angle, such that, when the stem is mounted straight in the metacarpus, the distal surface portion of the head can be located in varus.

Abstract: A spacer member (1) is intended to be placed between the ends of the bones which are to be connected, one end of the spacer member being designed to form a joint surface against one of the bone ends (6,7). A joint-stabilizing connection (2,3) is arranged to connect the bones. The spacer member (1) is made of at least one tissue-compatible material.

Abstract: A prosthetic medical device exhibiting improved wear resistance is fabricated by irradiating at least one polyolefinic material in the presence of an inert atmosphere to yield a cross-linked irradiated polyolefinic material; blending at least one non-irradiated polyolefinic material with the at least one irradiated polyolefinic material, and forming the prosthetic medical device from the blended material. 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 joint prosthetic component that includes first and second arms, and a joint member interposed therebetween. The joint member is configured to permit flexion motion between the first and second arms, and includes a first concave surface and a second concave surface. The first concave surface has a plurality of arcuate portions defined therein. The first and second concave surfaces are located on opposing sides of the joint member.

Abstract: The present invention provides an artificial joint which can be rapidly, securely and easily fixed while being suited to an inner surface of a bone marrow hole by a novel structure absolutely different from the conventional one. An artificial joint is provided with a stem base portion (10) in which a desired head (2) and a desired socket (5) are in slidably contact with each other in a freely bending manner, stems (9, 16) are fitly attached to free ends of the head (2) and the socket (5) respectively, and the respective stems (9, 16) have therein locking screws (14) freely screwing to move along axial directions thereof, and a pair of stem pieces (15) having an elasticity provided to protrude on both front portions of the stem base portion (10), and the locking screws (14) are forcedly inserted within the stem pieces (15) so as to expand them outward, thereby making them tightly contact with and fix to inner surfaces of bone marrow holes (19, 21).

Abstract: The present invention is a method of making a lubricious polyacrylonitrile artificial joint of a predetermined form and the resulting product. The method includes preparing a solution of a room temperature solvent that will dissolve polyacrylonitrile at room temperature and a room temperature non-solvent that will not dissolve polyacrylonitrile at room temperature. The solution is prepared with sufficient non-solvent to render the room temperature solvent inoperable for polyacrylonitrile at room temperature and operable at temperatures above 65° C. to dissolve polyacrylonitrile therein. Next, the polyacrylonitrile and the solution are combined into a mixture, in an amount of at least 20%, by weight, of polyacrylonitrile. The mixture is then heated at temperatures in excess of 65° C. to produce a fluid polyacrylonitrile product, and processed into an artificial joint component mold. Next, the product is cooled and may be rinsed, solvent extracted and dried. It is then treated chemically, e.g.

Abstract: First and second elements that have mating heads form an interphalangeal joint prosthesis that allows smooth articulation dorsal to volar. The first element head has a proximal surface defined by two intersecting planes, a stem portion that extends longitudinally therefrom and a convex bicondylar articulating surface having a central valley. The second element has a biconcave articulating proximal surface which mates with the first element articulating surface and a stem portion that extends longitudinally from the distal surface thereof, with a notch being formed in a dorsal surface of the head at a location that does not disturb attachments to the dorsal tubercle or the function of the median band of the extensor expansion. Sets of such joint prostheses of varying sizes are provided which are designed so that adjacent sizes interfit. A method for treating a deteriorated PIP joint is described.

Abstract: The present invention provides a joint prosthesis system for the joining of two bones. The bioabsorbable joint prosthesis system includes at least one bioabsorbable spacer and at least one connector adapted to be fixedly attached to the two bones, at least a portion of the connector being in contact with the spacer to prevent lateral movement of the spacer. The present invention also includes embodiments drawn to methods of using the joint prosthesis system. In an embodiment of the present invention, the method includes interposing at least one bioabsorbable spacer between the surface of the bones to be joined and connecting the bones with at least one connector such that at least a part of the connector contacts the bioabsorbable spacer.

Abstract: A joint prosthetic component that includes first and second arms, and a joint member interposed therebetween. The joint member is configured to permit flexion motion between the first and second arms, and includes a first concave surface and a second concave surface. The first concave surface has a plurality of arcuate portions defined therein. The first and second concave surfaces are located on opposing sides of the joint member.

Abstract: An arthroplasty joint assembly for medically and articulately interconnecting first and second opposed end regions of lengthwise adjacent first and second bones. The artificial joint assembly includes a first assembly including external threading extending lengthwise from a generally pointed end of the first assembly for anchoring the first assembly within a cavity of the first bone such that an opposite end of the first assembly extends toward the second bone. The artificial joint assembly also includes a second assembly having external threading extending lengthwise from a generally pointed end of the second assembly for anchoring the second assembly within a cavity in the second bone and such that an opposite end of the second assembly extends toward the first bone.

Abstract: A finger joint prosthesis for MP joint or PIP joint in which a socket has an opening at a portion thereof and a spherical face on an inner side thereof and is integrally formed with a stem on a side opposed to the opening, a head has a spherical portion fit to the spherical face via the opening and is integrally formed with a stem extending outwardly from the opening and a sheath for surrounding the stem of either of the socket and head is provided and the stem is movable slidably in an axial direction by adhering and fixing the sheath to a narrow cavity at a nearly disposed portion or a remotely disposed portion whereby the joint prosthesis is matched with motional characteristic of finger.

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: The invention shows an artificial finger joint comprising a convex joint head and comprising a concave joint shell which can be fastened independently of one another with a respective shaft in a bone end and which can be moved in an articulation plane from an extension position with parallel shaft axes into a hyperextension position or into an articulation end position. A guide pin projects out of the joint shell in the direction of its shaft axis and protrudes into a pocket of the joint head, with the pocket having a first abutment for the guide pin in the hyperextension position. A second abutment between the joint shell and the joint head prevents a tilting of the guide pin and shaft of the joint shell about the first abutment in hyperextension position.

Abstract: First and second elements that have mating heads form an interphalangeal joint prosthesis that allows smooth articulation dorsal to volar. The first element head has a proximal surface defined by two intersecting planes, a stem portion that extends longitudinally therefrom and a convex bicondylar articulating surface having a central valley. The second element has a biconcave articulating proximal surface which mates with the first element articulating surface and a stem portion that extends longitudinally from the distal surface thereof, with a notch being formed in a dorsal surface of the head at a location that does not disturb attachments to the dorsal tubercle or the function of the median band of the extensor expansion. Sets of such joint prostheses of varying sizes are provided which are designed so that adjacent sizes interfit. A method for treating a deteriorated PIP joint is described.

Abstract: The implant (11) has an anchoring part (15) with an axis (13), a generally cylindrical section and a peripheral surface (21). The latter is provided, in the generally cylindrical section, with protuberances (27) which are distributed around the axis (13). At least the majority of these protuberances are elongate and parallel with the axis (13) and have at least one terminal surface which is contiguous with a recess (23) having a base formed by the peripheral surface (21). In this way, the anchoring part (15) can be pushed into a substantially cylindrical hole (2) in a bone (1) such that the implant (11) is immediately anchored in the bone (1) in a stable manner, said implant nevertheless having a high degree of strength.