Spinal disk implant

• US 5,306,307 A
• Filed: 07/22/1991
• Issued: 04/26/1994
• Est. Priority Date: 07/22/1991
• Status: Expired due to Term

• Current Assignee: Zimmer Dental Inc. (Zimvie Incorporated)
• Original Assignee: Calcitek, Inc.
• Inventors: Senter, Howard J., Wagner, William R., Lariviere, Richard L.
• Primary Examiner(s): Green, Randall L.
• Assistant Examiner(s): BURKE, ELIZABETH
• Application Number:
  US07/733,710
• Time in Patent Office: 1,009 Days
• Field of Search: 623/17, 623/11
• US Class Current: 623/17.16
• CPC Class Codes: A61F 2/442 Intervertebral or spinal discs, e.g. resilient non-disc-shaped intervertebral inflatable pockets A61F2/441; non-disc-shaped intervertebral fusion implants A61F2/4455
• CPC Class Codes: A61F 2/4455 for the fusion of spinal bodies, e.g. intervertebral fusion of adjacent spinal bodies, e.g. fusion cages intervertebral discs A61F2/442
• CPC Class Codes: A61F 2002/2817 Bone stimulation by chemical reactions or by osteogenic or biological products for enhancing ossification, e.g. by bone morphogenetic or morphogenic proteins [BMP] or by transforming growth factors [TGF]
• CPC Class Codes: A61F 2002/30677 Means for introducing or releasing pharmaceutical products, e.g. antibiotics, into the body
• CPC Class Codes: A61F 2002/3082 Grooves
• CPC Class Codes: A61F 2002/30841 Sharp anchoring protrusions for impaction into the bone, e.g. sharp pins, spikes
• CPC Class Codes: A61F 2002/30879 Ribs
• CPC Class Codes: A61F 2002/30892 parallel
• CPC Class Codes: A61F 2002/30904 serrated profile, i.e. saw-toothed
• CPC Class Codes: A61F 2310/00023 Titanium or titanium-based alloys, e.g. Ti-Ni alloys
• CPC Class Codes: A61F 2310/00179 Ceramics or ceramic-like structures
• CPC Class Codes: A61F 2310/00293 containing a phosphorus-containing compound, e.g. apatite
• CPC Class Codes: A61F 2310/00389 The prosthesis being coated or covered with a particular material
• CPC Class Codes: A61L 2430/38 for reconstruction of the spine, vertebrae or intervertebral discs

Abstract

A spinal disk implant is implanted between vertebrae of the human spine following discectomy. The implant comprises a solid body having four sides and a pair of spaced-apart, opposed bases. The four sides include spaced-apart, opposed anterior and posterior faces, and a pair of spaced-apart, opposed transverse faces. Each transverse face has an anterior platform adjacent to the anterior face. The anterior platform is spaced apart from the opposed anterior platform by a maximum anterior platform spacing. A posterior ledge is oriented at an insertion angle relative to an opposed posterior ledge of the opposed transverse face. At least one of the posterior ledges has a pattern of serrations. There is a ridge on at least one of the transverse faces, positioned between the anterior platform and the posterior ledge and extending in the direction perpendicular to the bases. The top of the ridge is spaced apart from the opposed transverse face by an amount greater than the anterior platform spacing. The implant is desirably formed at least in part from a material that bonds with natural bone after implant, such as the ceramic hydroxylapatite.

Claims

1. A biocompatible spinal disk implant, comprising a solid body having four sides and a pair of spaced-apart, opposed bases, the four sides including spaced-apart, opposed anterior and posterior faces, and

a pair of spaced-apart, opposed transverse faces, each transverse face having

an anterior platform directly adjacent to the anterior face, the anterior platform being spaced apart from an opposed anterior platform by a maximum anterior platform spacing, and

a posterior ledge directly adjacent to the posterior face and being oriented at an insertion angle relative to an opposed posterior ledge of an opposed transverse face, at least one of the posterior ledges having thereon a pattern of serrations;

and

a ridge on at least one of the transverse faces positioned between the anterior platform and the posterior ledge and extending in a direction perpendicular to the bases, a top of the ridge being spaced apart from the opposed transverse face by an amount greater than the anterior platform spacing.

2. The implant of claim 1, wherein the implant is made of a ceramic.

3. The implant of claim 1, wherein the implant is made of ceramic-coated metal.

4. The implant of claim 2, wherein the ceramic is hydroxylapatite.

5. The implant of claim 3, wherein the ceramic is hydroxylapatite.

6. The implant of claim 3, wherein the metal is selected from the group consisting of titanium and a titanium alloy.

7. The implant of claim 1, wherein the implant is made of a material that bonds to natural bone.

8. The implant of claim 1, wherein the implant is made of a microporous material.

9. The implant of claim 1, wherein the ridge is rounded at the top.

10. The implant of claim 1, wherein the insertion angle is from 0 to about 10 degrees.

11. The implant of claim 1, wherein the insertion angle is from 0.5 to about 10 degrees.

12. The implant of claim 1, wherein a surface of the ridge is smooth.

13. The implant of claim 1, wherein a spacing of the posterior ledges at an end adjacent to the ridge is no greater than the spacing of the anterior platforms.

14. The implant of claim 1, wherein the implant is made at least in part of biocompatible orthopedic polymer materials.

15. The implant of claim 1, further including a pattern of serrations on at least one of the anterior platforms, the pattern of serrations extending in a direction perpendicular to the bases.

16. The implant of claim 1, wherein both of the transverse faces have a ridge thereon.

17. A biocompatible spinal disk implant, comprising a solid body having four sides and a pair of spaced-apart, opposed bases, the four sides including spaced-apart, opposed anterior and posterior faces, and

a pair of spaced-apart, opposed transverse faces, each transverse face having

an anterior platform directly adjacent to the anterior face, the anterior platform being spaced apart from an opposed anterior platform by a maximum anterior platform spacing, and

a posterior ledge directly adjacent to the posterior ledge and being oriented at an insertion angle relative to an opposed posterior ledge of an opposed transverse face;

and

a ridge on at least one of the transverse faces positioned between the anterior platform and the posterior ledge and extending in a direction perpendicular to the bases, a top of the ridge being spaced apart from the opposed transverse face by an amount greater than the anterior platform spacing, at least one of the anterior platform, the posterior ledge, and the ridge being bowed outwardly.

18. The implant of claim 17, wherein at least one of the anterior platforms is bowed outwardly when viewed perpendicular to the anterior face.

19. The implant of claim 18, wherein a degree of bowing, as measured by a ratio of a height of a bow to a distance between the bases, is more than 0 and no greater than about 0.2.

20. The implant of claim 17, wherein at least one of the posterior ledges is bowed outwardly when viewed perpendicular to the posterior face.

21. The implant of claim 20, wherein a degree of bowing, as measured by a ratio of a height of a bow to a distance between the bases, is more than 0 and no greater than about 0.2.

22. The implant of claim 17, wherein the ridge is bowed outwardly when viewed perpendicular to the anterior face.

23. The implant of claim 22, wherein a degree of bowing, a measured by a ratio of a height of a bow to a distance between the bases, is more than 0 and no greater than about 0.2.

24. The spinal disk implant of claim 17, wherein at least one of the posterior ledges has a pattern of serrations thereon.