Abstract:
A prosthetic knee having as its component parts a femoral implant, a tibial implant, and a meniscal plate disposed between the implants. Knee flexion and extension is permitted by compoundly curved condyle surfaces of the femoral implant, which resemble corresponding surfaces of a natural knee, and correspondingly shaped convex bearing surfaces in the meniscal plate. All other motions of the prosthetic knee take place at the interface between the meniscal plate and tibial implant. This interface is defined by a continuous, concave, spherically shaped surface in the upwardly facing plateau of the tibial implant and a corresponding, continuous, convex spherical surface of the meniscal plate. The components are biased into mutual engagement along the cooperating concave and convex surfaces by the natural ligaments which surround the prosthetic knee. The continuous biased engagement of the cooperating convex and concave surfaces of the prosthetic knee assure its stability.
Abstract:
This invention relates to endo-prosthetic knee joint devices.A knee prosthesis according to the invention comprises a femoral component for attachment to the femur and having a bearing surface including a first inferior curved portion and a second posterior portion contiguous with and of relatively lesser curvature than said first portion, a tibial component for attachment to the tibia and having a concave bearing surface and a meniscal component to lie between the femoral and tibial components and having bearing surfaces complementary to said first portion of the bearing surface of the femoral component and to the bearing surface of the tibial component.
Abstract:
Prosthetic replacement of an elbow joint is accomplished using a humeral component having an articular surface comprising a concave surface in the coronal plane and a convex surface in the sagittal plane with such component being cemented along a superior U-slot to a surgically prepared humeral bone. The prosthesis also comprises an ulnar component having an articular surface defined by a convex surface in the coronal plane and a concave surface in the sagittal plane, its undersurface having a longitudinal arcuate keel and a dependent stem by which it is cemented to the surgically prepared ulnar bone. Optionally, the prosthesis may include a radial head component in the form of a dished button that can be cemented to the surgically prepared radial bone by a depending stem.
Abstract:
A slide prosthesis for the knee joint is provided to be secured free of cement, the tibia members, the femur members and the surface replacement for the knee cap having anchoring pins which are provided with a saw tooth-like or bone screw-shaped profile. The tibia and knee cap members are preferably made of carbon fibre-reinforced plastics material and the femur members of aluminium oxide ceramic material. In order to assist growth of the bone to the prosthesis members, the members are coated at the corresponding points with bio-active particles, such as apatite-containing glasses, apatite particles or dealbumined bone material.
Abstract:
An artificial humerus head has a groove in its exterior surface for receiving the long biceps tendon. A cover bridges the groove to form an elongated open-end channel for the tendon and makes it possible to arrange the long biceps tendon in the channel without separation thereof from the head.
Abstract:
A novel joint prosthesis, particularly suitable as a metacarpophalangeal joint prosthesis, is disclosed comprising first and second intramedullary plugs adapted to be secured to the walls of the intramedullary canals of the two bones forming the joint, and first and second components each comprising a bearing portion and a stem slidably received in a longitudinal bore provided in each of said intramedullary plugs. Transmission of stresses to the bone-prosthesis fixation interfaces is substantially reduced as a result of the freedom of motion of the stems within these longitudinal bores. In a preferred embodiment, axial rotation of one, but only one, of said stems with respect to the intramedullary plug receiving it is prevented. Use of preferred configurations for the bearing portions of the two components provides an accurate reproduction of the movement and degrees of freedom of the natural metacarpophalangeal joint.
Abstract:
An acetabular prosthesis comprises a body 41 of plastics material defining a part-spherical socket cavity 43 surrounded by a rim 44. A flange extends outwardly from the rim 44. At 48 it inclines from the rim 44 in the direction of the body 41 and at 49 it inclines from the rim in a direction away from the body 41, while lobes 46, 47 therebetween are correspondingly curved. This arrangement provides for a considerably increased area of bone in the acetabulum to be available as a cementing surface when the prosthesis is fitted into a reamed out hip acetabulum in the special circumstances of the invention which is that the axis of socket cavity 43 extends substantially transversely with no or little anteversion.
Abstract:
A hip prosthesis of which the pin is made in the form of a tube slit in the longitudinal direction in order to give it a transverse elasticity and means enabling the bone to regrow inside this pin. Said pin further comprises a crest or fin provided with openings.
Abstract:
A patella prosthesis having a plurality of bearing surfaces designed to provide low-friction interaction throughout the entire range of leg extension and flexure with a metal condylar replacement prosthesis is disclosed. The prosthesis provides a combination of a reinforced patella surface and a femoral prosthetic surface having both a prolonged anterior flange and a central opening for the passage of the cruciate ligaments.
Abstract:
An endoprosthesis composed of a first member constituting a prosthesis socket provided interiorly with a chamber presenting a receiving surface, a second member constituting a prosthesis head arranged to be inserted into the socket to be received in the chamber and presenting a surface engaging the receiving surface when the head is received in the chamber, and a shaft firmly connected to the head. The head is arranged to be inserted into the socket by insertion movement, relative to the socket, from an insertion position to an inserted position, and to be rotated, relative to the socket, between the inserted position and an installed state. The socket presents a boundary edge formed to present at least one corner which encloses the head when the head is in the installed state and which defines a deformation, and the surface of the head is provided with a groove extending in the direction toward the shaft and defining a deformation, the depth of the groove being approximately equal to the constriction presented to the insertion opening by the corner.