78 results about "Syme prosthesis" patented technology

A prosthetic ankle and foot combination has an ankle joint mechanism constructed to allow damped rotational movement of a foot component relative to a shin component. The mechanism provides a continuous hydraulically damped range of ankle motion during walking with dynamically variable damping resistances, and with independent variation of damping resistances in the plantarflexion and dorsiflexion directions. An electronic control system coupled to the ankle joint mechanism includes at least one sensor for generating signals indicative of a kinetic or kinematic parameter of locomotion and / or walking environment, the mechanism and the control system being arranged such that the damping resistances effective over the range of motion of the ankle are adapted automatically in response to such signals. Single and dual piston hydraulic damping arrangements are disclosed, including arrangements allowing independent heel-height adjustment.

Various embodiments of the present invention relate to an apparatus and method for reverse shoulder arthroplasty (e.g., reverse total shoulder arthroplasty). In one specific example, a glenoid component used to resurface the scapula may be provided. Of note, unlike traditional total shoulder arthroplasty the glenoid component in a reverse shoulder is convex rather than concave; it acts as a physical stop to prevent the superior migration of the humeral head—a typical occurrence in patients suffering from rotator cuff tear arthropathy (CTA).

This invention provides for a novel orthopedic prosthesis, specifically a prosthetic tibial component for a prosthetic total knee joint, that comprises two constructs, one being a metal base construct that engages the bone and the other being a polyethylene bearing construct that attaches to the metal base construct and articulates with a femoral prosthetic component on the opposing side of the joint. The metal base construct is composed of two different metals, one of which engages the bone surface and the other of which engages the polyethylene bearing construct. Each of these metals is selected so that its characteristics are well suited to its particular function. More particularly, the first metal (i.e., the one that engages the bone surface) is selected so as to provide a superior bone-engaging face, while the second metal (i.e., the one that engages the polyethylene bearing construct) is selected so as to provide a superior polyethylene-engaging face. By combining the different material characteristics of two different metals in the metal bone construct, it is possible to simultaneously form a superior bone-engaging face and a superior polyethylene-engaging face.

Pre-surgical planning for cranial and facial reconstruction includes preparing a computer generated jaw or skull model for determining a locational position for a dental implant, a surgical bone implant to repair missing bone in the cranium, install ear prostheses, and / or install nose prostheses. The computer generated jaw or skull model is made from medical imagery and computer aided design. A surgical guide is prepared with oversize holes in registration with analogs for the dental or surgical bone implants to be inserted at the locational positions determined by a dentist or surgeon in the jaw or cranial skull model. The surgical guide is fitted atop each analog, and the surgical guide is bonded to the jaw or skull model at a predetermined angle of the analog in the jaw or skull. The surgical guide is removed from the model attached to the law or skull of a patient for accurate drilling during the dental or surgical procedure for insertion of the implants into the jaw or skull of the patient.

Prostheses and methods for repair of a cervical fact joint. The articulating surfaces of the natural facets of the facet joint are removed only a sufficient amount to allow the insertion of flat or slightly curvilinear portions of protheses therebetween in an overlapping relationship. The portions are so inserted and the prostheses mounted by attachment to adjacent vertebrae. Also, a single natural facet may be similarly repaired with a single prosthesis.

A prosthetic mounting device for securing a prosthetic device on bone tissue. The device includes a bone screw and a prosthetic abutment attached to an aft end of the screw. The abutment engages and rigidly supports a prosthesis. A tapered collar extends radially outward from around the aft end of the threaded shaft. In one embodiment, the device also includes an installation handle connected to and extending axially from the abutment. A rotary driver is used to engage and rotate the handle. The handle detaches from the abutment under a predetermined torque load both to cue an installer that increased bone density requires that a different instrument be used and that bone density is sufficient to support both initial and long-term stabilization.

A dental prostheses modeling system includes a re-usable tray having in an upper part thereof a trough for receiving a semi-liquid casting material such as plaster of Paris or die stone, the trough having opposed vertical walls in which are formed alternating vertically disposed ribs and grooves for molding complementary shaped grooves and ribs in opposed sides of the base of a dental model casting molded in said tray. The trough has a base frame which overlies an upwardly concave lower cavity for receiving liquid die stone after the casting base has solidified, hardened and been removed. The base frame has therethrough an elongated aperture joining the upper trough to the lower cavity. A resilient insert is removably lodged in the base frame aperture to form therewith a liquid-tight seal, whereupon liquid die stone is poured into the upper trough to form the base of a dental model casting. After the casting has hardened, the insert is removed, and pins are fitted into selected portions of the cast base. The tray is then inverted to receive liquid die stone which hardens to form a stone base matrix for insertably receiving pins protruding from the casting base. The casting is then severed into segments which are releasably re-engageable along with adjacent portions of the casting within the tray, proper registration between segments of the casting being effected by insertable receipt of pins within holes formed in the matrix during hardening thereof, and engagement between ribs and grooves of the casting segment bases with complementarily-shaped grooves and ribs in the inner side walls of the upper tray trough.

A above knee prosthesis (P) applied to femoral connection (100) of an amputee that comprises a upper hinge (1) connected to femoral connection of the patient, an articulation axis (2) with the function of reproducing the knee movements, a tibia-calf muscle unit (3) pivotally connected to the femoral•segment and a damper (5) that reproduces some functions of the calf muscle and ensures to the prosthesis to brake and to allow the sequential swing and stance phases typical of the gait. The damper comprises a cylinder (5c) wherein a piston (10) and a stem (9) act connected to each other and adapted to carry out a damping reaction of said damper responsive to the forces loaded on the prosthesis. In particular, a force transducer is provided in the damper arranged, in particular, in the stem with a microprocessor that receives a force signal from the transducer and operates means for adjusting the reaction of the damper responsive to the detected force signal.

A limb prosthesis which via coupling means is adapted to be connected to an implant in the form of an osseointegrated shaft projecting from an amputated stump. The coupling means comprises a flexible joint and the prosthesis further comprises at least one force transmitting device secured to and extending from a prosthetic member connected to the coupling means up to a position on the amputated stump or body portion to which the stump connects. The force transmitting device is adapted to be secured to the stump or other body portion in such a way that it relieves the implant from at least part of the bending and / or rotational forces exerted to the prosthetic member.

A joint prosthesis includes e.g., a femoral component and a tibial component. The medial and lateral condylar articular surfaces may have substantially uniform and equal radii from full extension to about 90° of flexion. From 90°, the lateral condylar articular surface has a smaller radius than the medial condylar articular surface such that the medial condyle gradually becomes increasingly more proud than the lateral condyle to facilitate internal rotation of the tibia at deep flexion. Also, the tibial articular component may include a post intermediate the medial and lateral compartments that engages a cam on the femoral articular component between the medial and the lateral condylar articular surfaces. The cam and post become congruent at flexion angles of approximately 70° flexion and mate symmetrically during the first 20°-30° of further flexion, and then mate asymmetrically at greater degrees of flexion to force internal rotation of the tibia.

A device to couple a prosthesis to a human leg stump above-the-knee in a first embodiment, and below the knee in the second embodiment. The device has an upper and a lower plate, the connecting mechanism being disposed in the lower plate. The upper plate is round and the same in both embodiments, but for above-the-knee junctions, the lower plate is elliptical while for below-the-knee junctions, the lower plate is round and of the same diameter as the upper plate. The operative connection is achieved by use of a guillotine, whose horizontally disposed blade engages one of a plurality of grooves on a locking stud. The movement of the spring-loaded guillotine is controlled by a retractable release pin to permit the guillotine to engage in or disengage the groove to which is disposed.

A prosthetic elbow for replacing an elbow of a dog or a human to restore normal, pain-free joint function. The elbow includes a humeral component for attachment to a humerus and a radioulnar component for attachment to an ulna. The humeral component includes a generally cylindric spool having a contoured external surface defining a first articular surface. The radioulnar component has a generally U-shaped contour with an inner peripheral surface defining a second articular surface sized and shaped for engagement with the first articular surface. Positional guides provide for implantation at precise locations.