Ventral intervertebral implant

• US 5,800,547 A
• Filed: 10/24/1996
• Issued: 09/01/1998
• Est. Priority Date: 08/20/1994
• Status: Expired due to Term

• Current Assignee: Depuy Spine Sarl (Johnson & Johnson)
• Original Assignee: Schafer micomed GmbH
• Inventors: Schmitz, Stephan, Schafer, Bernd
• Primary Examiner(s): Willse, David H.
• Application Number:
  US08/736,437
• Time in Patent Office: 677 Days
• Field of Search: 623/17, 606/61, 606/63, 606/68
• 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 2/4611 of spinal prostheses
• CPC Class Codes: A61F 2002/30364 Rotation about the common longitudinal axis
• CPC Class Codes: A61F 2002/30405 made by screwing complementary threads machined on the parts themselves
• CPC Class Codes: A61F 2002/30556 for adjusting thickness
• CPC Class Codes: A61F 2002/30579 with mechanically expandable devices, e.g. fixation devices
• CPC Class Codes: A61F 2002/30772 Apertures or holes, e.g. of circular cross section
• CPC Class Codes: A61F 2002/30777 Oblong apertures
• CPC Class Codes: A61F 2002/30785 parallel
• CPC Class Codes: A61F 2002/30797 internally-threaded
• CPC Class Codes: A61F 2002/30841 Sharp anchoring protrusions for impaction into the bone, e.g. sharp pins, spikes
• CPC Class Codes: A61F 2002/30892 parallel
• CPC Class Codes: A61F 2002/30904 serrated profile, i.e. saw-toothed
• CPC Class Codes: A61F 2220/0025 Connections or couplings between prosthetic parts, e.g. between modular parts; Connecting elements
• CPC Class Codes: A61F 2220/0033 made by longitudinally pushing a protrusion into a complementary-shaped recess, e.g. held by friction fit
• CPC Class Codes: A61F 2250/0009 for adjusting thickness

Abstract

A ventral intervertebral implant is used between two vertebral bodies of a spinal column. The implant has an upper and a lower contact surface and at least one anchor pin projecting beyond at least one of the contact surfaces. An instrument is provided for engagement with the implant and which extends as many anchor pins as are provided relative to the contact surfaces. The instrument is removable from the implant.

Claims

1. A ventral intervertebral implant for use between two vertebral bodies of a spinal column, comprising:

a ventral intervertebral body having an upper and lower contact surface, at least one opening extending generally perpendicular to said contact surfaces, and a further opening extending generally parallel to said contact surfaces and situated to intersect said at least one opening;

an anchor pin situated in each opening that extends generally perpendicular to said contact surfaces and projecting beyond at least one of said contact surfaces, each anchor pin being retractably disposed in its respective opening; and

a camshaft situated in said further opening for extending each anchor pin into a work position, wherein said camshaft is removable from said further opening after each anchor pin is situated in its work position.

2. The ventral intervertebral implant as defined by claim 1, wherein said camshaft has at least one cam that pushes out a respective anchor pin.

3. The ventral intervertebral implant as defined by claim 1, wherein a plurality of anchor pins are provided, and wherein said plurality of anchor pins can be pushed out via a respective one of a plurality of rotatably seated cams.

4. The ventral intervertebral implant as defined by claim 3, wherein said plurality of rotatably seated cams are disposed axially one behind the other.

5. The ventral intervertebral implant as defined by claim 4, wherein at least one disk-shaped collar that projects beyond said plurality of rotatably seated cams is provided between any two adjacent ones of said rotatably seated cams.

6. The ventral intervertebral implant as defined by claim 5, wherein said disk-shaped collar forms a seating position of said camshaft.

7. The ventral intervertebral implant as defined by claim 1, wherein said camshaft is ventrally accessible.

8. The ventral intervertebral implant as defined by claim 1, wherein said camshaft can be rotated by a tool.

9. The ventral intervertebral implant as defined by claim 1, wherein one face end of said camshaft has an interior thread for a corresponding tool-application device.

10. The ventral intervertebral implant as defined by claim 3, wherein the regulating distance of said rotatably seated cams extends over one of 90°

, 180°

, and 360°

.

11. The ventral intervertebral implant as defined by claim 3, wherein each of said rotatably seated cams is provided with two regulating distances respectively extending over 180°

.

12. The ventral intervertebral implant as defined by claim 1, wherein said camshaft has a rotational stop.

13. The ventral intervertebral implant as defined by claim 1, wherein each anchor pin has a cylindrical cross-section and is seated in a corresponding opening in the implant.

14. The ventral intervertebral implant as defined by claim 1, wherein the implant is embodied to be wedge-shaped, and said contact surfaces form a wedge angle (α

) of 2°

to 15°

.

15. The ventral intervertebral implant as defined by claim 1, wherein the implant has a thickness of 5 mm to 14 mm, and, with a wedge shape, a thickness of 5 mm to 8 mm or 8 mm to 14 mm.

16. The ventral intervertebral implant as defined by claim 1, wherein at least one of said contact surfaces has a profiled surface.

17. The ventral intervertebral implant as defined by claim 16, wherein each of said two contact surfaces have sawtooth profiles located opposite to one another and which point in different directions.

18. The ventral intervertebral implant as defined by claim 17, wherein the sawtooth profiles point in the ventral direction and the dorsal direction.

19. The ventral intervertebral implant as defined by claim 16, wherein the profiled surface is a toothed surface.

20. The ventral intervertebral implant as defined by claim 1, wherein said camshaft can be threaded on a rod-shaped tool.

21. The ventral intervertebral implant as defined by claim 1, wherein said camshaft can be inserted dorsally or ventrally into the implant.

22. The ventral intervertebral implant as defined by claim 1, further having a device which maintains each anchor pin in a work position.

23. The intervertebral implant as defined by claim 22, wherein said device is releasable.

24. The ventral intervertebral implant as defined by claim 1, wherein the implant is embodied to be wedge-shaped, and said contact surfaces form a wedge angle (α

) of 3°

to 10°

.