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US 8,133,284 B2Granted
Hip prosthesis with monoblock ceramic acetabular cup
AssigneeAmedica Corporation
InventorsK. Scott Ely, Ashok C. Khandkar, Ramaswamy Lakshminarayanan, Aaron A. Hofmann
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Abstract
An improved hip prosthesis includes an acetabular cup bearing component constructed from a relatively hard and high strength ceramic material for articulation with a ball-shaped femoral head component which may be constructed from a compatible ceramic or metal material. In one form, the acetabular cup further includes a ceramic porous bone ingrowth surface adhered thereto for secure ingrowth attachment to natural patient bone.
Claims13
A hip joint prosthesis, comprising:
- a monolithic acetabular cup defining a convex upper side having a size and shape adapted for seated engagement within a patient's natural acetabulum, and a lower side defining a downwardly open and generally part-spherical cavity lined by an articulation surface having a size and shape for articulatory reception of a matingly shaped femoral component;
- said acetabular cup defining a relatively low porosity first region defining said articulation surface, and a comparatively higher porosity second region defining a bone ingrowth surface on said convex upper side thereof, wherein both of said first region and said second region comprise doped silicon nitride ceramic;
- said doped silicon nitride ceramic of said relatively low porosity first region having a flexural strength greater than about 700 Mega-Pascal (MPa) and a fracture toughness greater than about 7 Mega-Pascal root meter (MPam0.5), and comprising one or more dopants selected from the group of dopants consisting of yttrium oxide, magnesium oxide, strontium oxide, and alumina.
A hip joint prosthesis, comprising:
- a monolithic acetabular cup defining a convex upper side and having a size and shape adapted for seated engagement within a patient's natural acetabulum, and a lower side defining a downwardly open and generally part-spherical cavity lined by an articulation surface having a size and shape for articulatory reception of a matingly shaped femoral component;
- said acetabular cup being formed from a doped silicon nitride ceramic material having a flexural strength greater than about 700 Mega-Pascal (MPa) and a fracture toughness greater than about 7 Mega-Pascal root meter (MPam0.5), and comprising one or more dopants selected from the group of dopants consisting of yttrium oxide, magnesium oxide, strontium oxide, and alumina;
- and
- said acetabular cup having a rim defined by the circumferential free edge between said upper and lower sides, and wherein said rim includes a pair of generally identically-shaped and diametrically opposed recesses formed therein for increased range of motion, wherein each recess extends from said upper side to said lower side.
1 more element
Dependencies are inferred from the claim text.