Femoral head and method of manufacture thereof
AssigneeThe Curators of the University of Missouri
InventorsMohamed Naushad Rahaman, Bhajanjit Singh Bal, Yadong Li
Life of this patent
Estimating the term…
Abstract
A femoral head made from a ceramic-metal composite having a multi-layered construction and related method of manufacture is disclosed. The femoral head includes an inner metal core bonded to a relatively thin ceramic outer layer that is used as the articulating surface with an acetabular cup during total hip arthoplasty. In another embodiment, an interface layer having a ceramic and metal mixture may be laminated between the inner metal core and the exterior ceramic layer.
Claims21
A femoral head comprising:
- an inner metal core bonded to a ceramic outer layer, the ceramic outer layer having an interface layer and an exterior ceramic layer bonded to the interface layer, wherein the thickness of the interface layer ranges between about 0.5 mm and about 2 mm, and the thickness of the exterior ceramic layer ranges between about 200 microns and about 10 mm.
A femoral head comprising:
- an inner metal core bonded to an exterior ceramic layer, wherein the exterior ceramic layer has a thickness ranging between about 200 microns and about 10 mm, and the coefficient of thermal expansion of the inner metal core differs by no more than about 50% from the coefficient of thermal expansion of the exterior ceramic layer.
An orthopedic implant component comprising:
- a. a support member comprising a homogeneous metallic species composition;
- b. a secondary interface layer bonded to the support member, the secondary interface layer comprising:
- i. a first sub-layer comprising between about 5% and about 95% of a ceramic material and between about 95% and about 5% of a metal material by volume;
- ii. a second sub-layer comprising between about 5% and about 95% of a ceramic material and between about 95% and about 5% of a metal material by volume;
- iii. a third sub-layer comprising between about 5% and about 95% of a ceramic material and between about 95% and about 5% of a metal material by volume;
- and,
- c. a ceramic composition bonded to the interface layer opposite the support member, the ceramic composition selected from the group consisting of a ceramic material, a metallic species, and combinations thereof, whereby the thickness of the ceramic composition layer ranges between about 200 microns and about 10 mm.
A method of making an orthopedic implant component having three separate compositions, wherein the compositions differ by no more than about 50% in coefficients of thermal expansion and the compositions differ by no more than about 1000° C. in melting points, the method comprising:
- a. mixing a metal powder with a sintering additive to form a mixed metal powder;
- b. cold pressing the mixed metal powder to a desired shape to form a shaped metal product;
- c. mixing metal powder and ceramic powder and layering the mixture over the shaped metal product to form a transition layer;
- d. cold pressing the transition layer to a desired shape to form a shaped metal product;
- e. layering additional successive layers of ceramic powder onto the interface layer to form an exterior ceramic layer that forms an implant;
- f. cold-pressing the implant then hot-pressing to sinter all of the layers into a solid phase;
- and,
- g. grinding and polishing the exterior ceramic layer to the desired size.
A method of making an orthopedic implant component having three separate compositions, wherein the compositions differ by no more than 50% in coefficients of thermal expansion, the method comprising:
- a. forming an inner metal core;
- b. forming an interface layer over the inner metal core whereby the interface layer material has a melting point within about 1000° C. of the melting point of the inner metal core;
- c. forming an exterior ceramic layer over the interface layer whereby the exterior ceramic layer has a melting point within about 1000° C. of the melting point of the inner metal core and the interface layer;
- and,
- d. bonding the inner metal core, the interface layer, and the exterior ceramic layer.
Dependencies are inferred from the claim text.