Space holder for vertebrae or intervertebral discs
The present invention concerns a space holder, especially for vertebrae or intervertebral discs for implantation into human or animal organisms, having a cylinder-like body ( 1 ) and, at the ends of the cylinder-like body, means ( 2 ) provided for connecting to adjacent body parts, said cylinder-like body ( 1 ) essentially being formed as a solid cylinder from at least one material that is elastically deformable under the conditions of use, such that the space holder is compressible and extensible in the axial direction and, with reference to means ( 2 ) provided at the ends for connecting the space holder to adjacent body parts, can bend about a radial axis of rotation ( 13 ).
1. A space holder for vertebrae or intervertebral discs for implantation into living human or animal organisms, the space holder comprising:
a cylinder-like body having a first end and a second end, the body defining a longitudinal axis extending from the first end to the second end and having an outwardly facing cylinder-like surface extending in a direction of the longitudinal axis at each of the first and second ends of the cylinder-like body;
first and second connecting members to connect to adjacent body parts provided at the first and second ends, respectively, of the cylinder-like body, each of the first and second connecting members having a ring-like shape and having an inwardly facing ring-like surface extending primarily in a direction of the longitudinal axis that is connected to and contacts the outwardly facing cylinder-like surface at the first and second ends of the cylinder-like body, respectively;
wherein each of the first and second connecting members has a central opening therethrough having an outer diameter defined by the inwardly facing ring-like surface such that at least a portion of the first end and at least a portion of the second end of the cylinder-like body is exposed through the central opening of the first and second connecting member, respectively;
wherein the cylinder-like body is formed as a solid body from at least one material that is elastically deformable under the intended conditions of use;
wherein the space holder is compressible and extensible in an axial direction and is bendable about a radial axis of rotation; and
wherein the first and second connecting members have at least one cavity comprising a recess extending only as far as the cylinder-like body between the ends of the cylinder-like body and a fully-open aperture outside the ends of the cylinder-like body.
2. The space holder of claim 1 , wherein the inwardly facing ring-like surface of each of the first and second connecting members defines inner surfaces of protrusions that project in a direction of the longitudinal axis of the cylinder-like body away from the cylinder-like body from the first end and the second end, respectively.
3. The space holder of claim 2 , wherein each of the first and second connecting members have a ring-like wall perforated therethrough.
4. The space holder of claim 3 , wherein the ring-like wall of the first and second connecting members includes a large number of fillets that are connected in one of a diamond shape and a wave shape.
5. The space holder of claim 2 , wherein the protrusions of the first and second connecting members at least partially protrude past the ends of the cylinder-like body.
6. The space holder of claim 2 , wherein the protrusions have at least one of a triangular and trapezoidal shape.
7. The space holder of claim 1 , wherein the first and second connecting members are connected by at least one of non-positively, frictionally, by form fit, and union of the members to the cylinder-like body.
8. The space holder of claim 1 , wherein the cylinder-like body, expressed in terms of its longitudinal direction, is at least one of elastically extendible and compressible by 0.5 to 20%.
9. The space holder of claim 8 , wherein the cylinder-like body is at least one of elastically extendible and compressible by 1 to 15%.
10. The space holder of claim 1 , wherein the cylinder-like body is bendable elastically about a radial axis, such that the first and second connecting members are swivelable by approximately 0.5 to 10° out of a longitudinal axis of the space holder.
11. The space holder of claim 10 , wherein the cylinder-like body is bendable elastically about a radial axis such that the first and second connecting members are swivelable by 1 to 6° out of the longitudinal axis of the space holder.
12. The space holder of claim 1 , wherein the cylinder-like body is formed from elastic material, which comprises a biocompatible polymer.
13. The space holder of claim 12 , wherein the cylinder-like body is formed from at least one of high molecular polyethylene and medical grade silicone rubber.
14. The space holder of claim 1 , wherein the cylinder-like body is at least one of composite material and a multi-component part.
15. The space holder of claim 1 , wherein, the solid body comprises a cylinder-like core and a co-axial cylinder pipe-like sleeve.
16. The space holder of claim 15 , wherein the sleeve and the core are different materials having different elasticity.
17. The space holder of claim 1 , further comprising a holding member to connect the cylinder-like body and the first and second connecting members together.
18. The space holder of claim 17 , wherein the holding member comprises a radially inwardly protruding rod on at least one of the first and second connecting members.
19. The space holder of claim 18 , wherein the holding member comprises an anti-twist stop.
20. The space holder of claim 1 , wherein the first and second connecting members are molded into or onto the cylinder-like body.
21. The space holder of claim 1 , wherein the cylinder-like body has a shoulder on each of its ends for receiving the first and second connecting members such that the cylinder-like body and the first and second connecting members are flush along an outwardly facing cylinder-like surface of the space holder.