Boehringer Mannheim Gmbh

Depuy

Depuy, Division of Boehringer Mannheim Corporation

Todd S Smith

David C Kelman

Richard C Bolesky

Charles E Whitcraft, Jr

John A Engelhardt

A technique for producing a highly convoluted surface on a prosthetic device is achieved by applying a layer of aspherical metallic powder on the surface of the device. The metallic powder, which may be the same as or different from the material of the device, is applied in a thickness of up to approximately 200 microns and has a size range of approximately -80 to +635 mesh so as to result in a desirable surface roughness defined by a peak to valley variation of up to approximately 200 microns. A resulting device has an enhanced surface which provides, alternatively, an improved press fit into a receiving bone, or improved cement fixation, or improved reception of a ceramic coating.

Prosthesis with highly convoluted surface

A modular hip prosthesis for the replacement of a portion of the femur is provided. The prosthesis is assembled from a kit that includes a stem member having an upper portion and a lower portion, with the lower portion sized to be received in the femur. The kit also includes a body member that is sized to replace a portion of the femur and is configured to be received over the upper portion of a stem member. The kit also includes a head member that is sized to replace the head of the femur. A neck member is provided to attach the head member to the body member to form an assembled prosthesis.

Modular hip prosthesis

A technique for producing a highly convoluted surface on a prosthetic device is achieved by applying a layer of aspherical metallic powder on the surface of the device. The metallic powder, which may be the same as or different from the material of the device, is applied in a thickness of up to approximately 200 microns and has a size range of approximately -80 to +635 mesh so as to result in a surface roughness defined by a peak to valley variation of up to approximately 200 microns. A resulting device has an enhanced surface which provides, alternatively, an improved press fit into a receiving bone, or improved cement fixation, or improved reception of a ceramic coating.

The invention relates to a prosthetic implant assembly comprising a base component secured to a bone and a generally planar surface having a recessed portion formed therein. A spring is situated in the recessed portion of the base component and includes a tab extending away from the spring. A bearing component slidably engages the base component to couple the bearing component to the base component and the bearing is provided with an opening for receiving the tab of the spring means therein to lock the bearing component in a fixed position relative to the base component.

Prosthetic implant locking assembly

A method of joining a polymeric part and a metallic or ceramic part. The result is a bearing for an orthopedic prosthesis comprising a rigid backing component presenting a mating surface having interstices, a polymeric bearing component having a corresponding mating surface, the bearing component and backing components being joined together by heating the backing component to a temperature sufficient to reduce the viscosity of the bearing component at its mating surface and by forcing the components together with sufficient pressure to cause the bearing component mating surface to flow into the interstices of the backing component mating surface.

Polymeric bearing component

An artificial implant includes an elongated stem member which is intended for cementless fixation in the medullary canal of a long bone. The stem member is provided with one or more longitudinally extending channels. A porous medium for enabling and encouraging bone ingrowth fixation is bonded to the bottom surface of each channel but is free of the sidewalls of the channel. It has a first outer surface lying in a plane generally parallel to that of the external surface of the stem member and second and third surfaces lying generally, respectively, in angularly spaced radial planes containing the longitudinal axis of the stem member. The resulting implant has a flexibility which can be tailored to that of the bone. Also, the porous medium enables an initial interference fit with the medullary canal of the long bone as well as bone ingrowth fixation over a substantially enlarged surface area than previously possible. Also, notching the high stress region on the external surface of the stem member as previously caused by application of the porous medium to the outermost, external, surface of the stem member is avoided.

Porous coated prosthesis

A controlled stiffness elongated implant for use in the hip or other appropriate body joint. In the instance of the hip, a ball member fixed to the femur is rotatably engaged with a cup-shaped socket member fixed to the acetabulum of the pelvic bone. The ball member is mounted on one end of a femoral component which has an elongated stem receivable in the intramedullary canal of the femur. The stem has a generally longitudinally directed reduced mid-stem section. The dimension of the reduced mid-stem section is uniform or variable between the proximal and distal ends so as to affect the mass moment of inertia at any given location along the length of said stem to thereby achieve an optimal stem flexibility.

Load sharing femoral hip implant

A controlled stiffness elongated implant for use in the hip or other appropriate body joint. In the instance of the hip, a ball member fixed to the femur is rotatably engaged with a cup-shaped socket member fixed to the acetabulum of the pelvic bone. The ball member is mounted on one end of a femoral component which has an elongated stem receivable in the intramedullary canal of the femur. The stem has a longitudinal channel therein which lies generally in the coronal plane when the stem is in the implanted condition. The thickness of the stem laterally of the channel is variable between the proximal and distal ends so as to affect the moment of inertia at any given location along the length of said stem to thereby achieve stem flexibility which substantially correlates to the flexibility of the bone.

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Warsaw, IN, United States of America

Todd S Smith