Abstract: A total ankle replacement system, novel surgical method for total ankle replacement, and novel surgical tools for performing the surgical method are described. The total ankle replacement system includes the calcaneus in fixation of a lower prosthesis body, thereby significantly increasing the amount of bone available for fixation of the lower prosthesis body and allowing the lower prosthesis body to be anchored with screws. The total ankle replacement system further includes a long tibial stem which can also be anchored into the tibia with, for example, screws, nails, anchors, or some other means of attachment. The novel surgical arthroscopic method allows introduction of ankle prostheses into the ankle joint through an exposure in the tibial tubercle. Various novel surgical instruments, such as a telescoping articulating reamer and a talo-calcaneal jig, which facilitate the novel surgical method, are also described.

Abstract: A protective cap for prosthetic joints having one element in the form of a ball head, especially in the case of hip end-prosthetic joints, protects the ball head when it is positioned and fixed on the cone of the shank by the surgeon by hand. A crown is arranged on the pole of the protective cap. The crown is in the form of a plate for, the shape of the plate and its extent relative to the protective cap being such that it is possible to grip behind the plate on the side that faces the protective cap.

Abstract: Disclosed is a prosthesis configuration and method for treating acquired flatfoot. The assembly includes a longitudinal piece extending into two foot bones. The piece is positioned such that a maximum force, in the piece, is a tension force when the foot is under a standing load. The piece may be a flexible cable, for example.

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 joint prosthesis for attachment to a bone of a patient, comprising an anchor with a head surface and a stem for attachment to an end of the bone, the head surface having an anatomically accurate shape.

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 implant has at least one contact surface portion, made of pyrolytic carbon, designed to be in mobile contact with at least one bony surface when the implant is implanted in a patient. Furthermore, the implant is free from any attaching means, so that it remains free with respect to the at least one bony surface when implanted in the patient.

Abstract: According to the state of the art, the replacement of a basal finger joint is effected by, for example, interposition of soft part tissue or a distance piece, which does not, however, constitute a replacement joint. In joint prostheses with a metal-metal sliding combination, but in particular with a metal/polyethylene sliding combination, wear of the material can lead to osteolyses at the bone ends. Owing to the tact that the metal or plastic joint prostheses known from the state of the art are as a rule multipart, loosening of the individual components can occur, which shortens the service life of the implant.

Abstract: Screw-based primary fixation of the prosthetic components within the medullary cavity solves the problem of micro-movements encountered in conventional press-fit cementless fixation. For a total hip prosthesis, the stem is fixed to the medial cortex of the proximal femur by the medial approach alone, obviating the need for drilling of the lateral cortex. The stem may be implanted using special drill guide instrumentation. Anchoring screws are locked into the stem of the femoral component, while self-cutting threads on the screw head engage the pre-drilled medial cortex. This novel fixation principle can also be applied to other joint prostheses, e.g. finger, shoulder, elbow and knee, as well as to dental and spinal implants.

Abstract: A prosthesis (1) for a metacarpophalangeal joint comprises a metacarpal plug member (2), a metacarpal insert member (3), and a phalangeal insert member (4). The metacarpal plug member (2) comprises an elongate body (5) which generally tapers from a proximal end (7) to a distal end (8), which has a central longitudinal axis (6), an axial bore (13), and a plurality of axially spaced first fins (9, 10, 11, 12) projecting from the elongate body (5) in a direction substantially perpendicular to the central longitudinal axis (6). The metacarpal insert member (3) comprising a head portion (15) having a convex articulating surface (17) and a stem portion (16) projecting distally from the head portion (15) for reception in the proximal end of the axial bore (6). The phalangeal insert member (4) comprises an enlarged proximal end portion (19) and an elongate shaft portion (21) that extends distally from the enlarged proximal end portion (19).

Abstract: In an endoprosthesis (11h) for a joint, the two interacting joint parts (15h, 16h) are joined by a cord-type connection piece (21h), which is attached in the vicinity of the body axis (M2h, M2h′) of the convex condyle (15h) and extends through a longitudinal groove (22h) in the flexion direction of the joint. The connection piece assures a play space (31h) between the contact surfaces (19h, h′, 20h, h′) of joint (11h). It is protected from friction on groove wall (55h, 55h′) by an elevation (50h, 43h) in concave joint part (16h). An elevation (43h, 50h) at concave joint part (16h) and a depression (49h) at convex joint part (15h) interact in such a way that the lateral movement play space between depression and elevation determines the freedom of movement with respect to the lateroflexion of the joint.

Abstract: The joint prosthesis includes a first part with a cylindrical socket and a second part with a cylindrical head. The cylindrical head and socket are of complementary form, in such a manner that together they are able to form a linear hinge. The cylindrical socket extends over at most 180° in the circumferential direction. The cylindrical head is provided with a radial thickened section which extends in the circumferential direction. The cylindrical socket is provided with a radial recess which extends in the circumferential direction and in which the radial thickened section can be accommodated, with the cylindrical head in bearing contact inside the cylindrical socket. The radial thickened section and radial recess are arranged centrally and are formed so as to be self-aligning with respect to one another.

Abstract: In a prosthetic device for joints for implantation in humans and animals, a joint body is arranged between two fixing elements which are intended to be connected to adjoining bone parts. The joint body includes at least one essentially helical spring, and the ends of each spring are connected to the fixing elements.

Abstract: A toe implant (10) for a first metatarsal phalangeal joint (22) between a metatarsal (24) and a proximal phalanx (26) of a great toe (12) includes a proximal stem (16), a distal stem (18) and a hinge (20) and a strength rib (92). Importantly, the toe implant (10) is designed to accommodate an axis of motion in a unique location (82) and the distal stem (18) is naturally positioned lower than the proximal stem (16). Further, the toe implant (10) provides a relatively good available range of motion. With this design, the toe implant (10) maintains the proximal phalanx (26) in the correct anatomic position relative to the metatarsal (24) during bending and flexing. Additionally, the toe implant (10) allows the toe (12) to move in a fashion that simulates the natural motion of the first metatarsal phalangeal joint (22). As a result thereof, the toe implant (10) that does not significantly increase the stress at the joint (22) or alter the normal flexing of the toe (12).

Abstract: An anatomical prosthesis for implantation after a resection of the distal ulna includes a head and a stem. The head is formed with a curved surface for articulation with the sigmoid notch of the distal radius. A bore is provided in the head to allow for attachment of the head to the stem. The head is further formed with suture holes for anchoring the head to the soft tissues such as the ulnar collateral capsule, the triangular fibrocartilage and the extensor carpi ulnaris subsheath that are exposed after resection of the distal ulna. The stem is elongated, having a proximal end for engagement with the intramedullary canal of the ulna, and a distal end for engagement with the bore formed in the head.

Abstract: A medical prosthesis for use within the body which is formed of radiation treated ultra high molecular weight polyethylene having substantially no detectable free radicals, is described. Preferred prostheses exhibit reduced production of particles from the prosthesis during wear of the prosthesis, and are substantially oxidation resistant. Methods of manufacture of such devices and material used therein are also provided.

Abstract: A prosthesis system for partial or total articular surface replacement includes a tail module having one or more grooves at one end thereof and a first ball joint component at an opposite end thereof; an articular module, a portion of which has an anatomic shape of a distal radial articular surface, another portion of which is provided with a second ball joint component; and a collar module interposed between the tail module and the articular module, and comprising a pair of sockets adapted to receive the first and second ball joint components of the tail module and articular module

Abstract: An ankle prosthesis, comprising a tibial element and an talar element (30), each provided with anchoring means on the lower extremity of a tibia and on the astragalus, respectively, and each delimiting an articular surface, both articular surfaces being shaped in order to interact as a whole and to provide a relative movement between the two tibial and talar elements around at last one axis. It is especially characterized by the fact that, taking as reference direction the direction of the axis of the tibia on which it is intended to anchor the tibial element, seen in projection on a plane approximately perpendicular to this reference direction, the articular surfaces are curved with a concavity towards the inside of the foot onto which is to be anchored the talar element.

Abstract: Wrist prosthesis with a carpus element (2) to be implanted in the metacarpal bones, a radial element (1) to be fixed on the bone of the forearm, and, arranged between these, a transverse axis articulation (3) whose proximal part (9) is connected to the radial element (1). According to the invention, the proximal part (9) of the transverse axis articulation (3) is available in two embodiments, the first of which is rigid per se and the second of which comprises a further articulation (25, 28), and that [sic] both embodiments of the proximal part (9) of the transverse axis articulation (3) are connected or can be connected releasably to the radial element (1) and to the distal part (18) of the transverse axis articulation (3).

Abstract: A system, method, and tools including a subtalar arthroereisis implant for use in reducing calcaneal eversion, blocking anterior and inferior displacement of the talus, and blocking excessive pronation and the resulting sequelae, while allowing normal subtalar joint motion. The method includes in the preferred system inserting a probe to slightly dilate the tarsal canal, inserting a cannulated “sizer” having a guide element placed therein into the dilated sinus tarsi resulting in the guide element being inserted through the tarsal canal. The sizer is removed, leaving the guide element in place. Once the implant has been sized, a trial implant in inserted by placing a conically shaped “nose cone” on the guide element ahead of the implant. Once the trial implant is in place, sizing is checked, the trial implant is removed, and the actual implant is inserted following generally the same procedure as for the trial implant.