Bone implant with plastic insert between elements of different mechanical properties
AssigneeSulzer Brothers Limited
InventorOtto Frey
Life of this patent
Estimating the term…
Abstract
The bone implant is made from elements which have different mechanical properties and which are maintained out of contact from each other by means of a plastic member. The plastic member is disposed in and fills a gap formed by the implant elements. In addition, the plastic member has thin-walled extensions which are engaged in narrowing sections at the outer boundaries of the gap. These extensions guard against any creep in the plastics member under the forces imposed on the plastics member during stressing of the bone implant.
Claims11
A bone implant construction comprising
- a pair of elements of different mechanical properties disposed in relative movable relation, said elements being disposed to transfer loading forces therebetween and to define a shaped predetermined gap therebetween with an abrupt transition to a narrowing section at at least one end of said gap, said section extending at least substantially in the direction of said loading forces;
- and
- a resiliently distortable removable plastic member confined in said gap to maintain said elements out of contact with each other, said plastic member having a cylindrical portion to surround one element and a narrowed thin-walled extension coaxial with said cylindrical portion and engaged in said narrowing section to inhibit cold plastic creep of said cylindrical portion from said gap at said one end.
A bone construction comprising
- a first element having a stem;
- a second element having a cavity receiving said stem of said first element in relative movable relation, said second element being spaced from said first element to define a predetermined cup-shaped gap therebetween with a narrowing section at an end of said gap;
- and
- a resilient cup-shaped plastic member removably disposed in said gap between said elements to maintain said elements out of contact with each other, said plastic member having a circular cylindrical portion in said gap and a narrowed thin-walled extension coaxial with said cylindrical portion engaged in said narrowing section.
A bone implant construction comprising
- a first element;
- a second element having a cavity receiving said first element in relative movable relation, said second element being spaced from said first element to define a predetermined annular gap therebetween with a narrowing section at opposite ends of said gap;
- and
- an annular resilient plastic member removably disposed in said gap between said elements to maintain said elements out of contact with each other, said plastic member having a circular cylindrical portion to surround said first element and a narrowed thin-walled extension coaxial with and at each end of said cylindrical portion engaged in a respective narrowing section.
Dependencies are inferred from the claim text.