Plate for osteosynthesis device and preassembling method

• US 20050010215A1
• Filed: 10/18/2002
• Published: 01/13/2005
• Est. Priority Date: 10/18/2001
• Status: Active Grant

• Current Assignee: LDR Medical
• Original Assignee: LDR Medical
• Inventors: Poncer, Remi, Ganglof, Serge, Delecrin, Joel, Tropiano, Patrick, Allain, Jerome
• Granted Patent: US 8,162,988 B2
• Time in Patent Office: Days
• US Class Current: 606/261
• CPC Class Codes: A61B 17/7001 Screws or hooks combined with longitudinal elements which do not contact vertebrae A61B17/7058 takes precedence
• CPC Class Codes: A61B 17/7007 Parts of the longitudinal elements, e.g. their ends, being specially adapted to fit around the screw or hook heads
• CPC Class Codes: A61B 17/701 Longitudinal elements with a non-circular, e.g. rectangular, cross-section A61B17/7005, A61B17/7007 take precedence
• CPC Class Codes: A61B 17/7011 Longitudinal element being non-straight, e.g. curved, angled or branched adjustable length longitudinal elements A61B17/7014; A61B17/7019 takes precedence, e.g. coil springs
• CPC Class Codes: A61B 17/7037 wherein pivoting is blocked when the rod is clamped
• CPC Class Codes: A61B 17/7041 with single longitudinal rod offset laterally from single row of screws or hooks A61B17/7044 takes precedence
• CPC Class Codes: A61B 17/7082 for driving, i.e. rotating, screws or screw parts specially adapted for spinal fixation, e.g. for driving polyaxial or tulip-headed screws driving other bone screws A61B17/8875
• CPC Class Codes: A61B 17/864 hollow, e.g. with socket or cannulated
• CPC Class Codes: Y10T 29/49826 Assembling or joining

Abstract

The present invention relates to an osteosynthesis device, particularly for spinal support or correction, enabling easier and compact implantation, that can be particularly used in the case of implantation via the anterior approach, and a preassembly method for such a device. Said device comprises implants screwed into two vertebrae (0) and a plate (2) used to hold and displace the spine. Said plate (2) comprises on at least one of its ends at least one longitudinally elongated opening, said opening having firstly at least one part opening onto an edge of the plate, or one part of a sufficiently large size (s210b) to be able to be inserted without disassembly in the fixation means of an implant (1) already screwed into the spine when said fixation means are already assembled.

Claims

1. Osteosynthesis device comprising a plurality of implants that are adapted to be joined to one or more vertebrae whereby being adapted to provide a rigid joint between said vertebrae and at least one support element comprising at least one plate or bar, and adapted to hold or displace a spine, wherein said plate is joined to at least two of said implants by an attachment structure;

wherein the plate has an elongated shape and comprises on at least one of its ends at least one longitudinally elongated opening, said opening having, firstly, at least one opening extending to an edge of the plate, or one part of a sufficiently large size to be able to be inserted, without disassembly, in the attachment structure of an implant that has previously been attached to a vertebrae of the spine when said attachment structures are already assembled, and, secondly, a part of a substantially constant width that is able to slide longitudinally in the attachment structure of said implant after having been inserted and of being fixed thereon;

wherein such a plate is adapted to be assembled at one end to first implant that has been attached to a vertebrae, and is adapted to then be caused to slide in relation to the attachment structure of said first implant so as to enable the other end of said plate to be inserted in a second implant that has previously been joined to a vertebrae, and then is adapted to be slid again in order to bring both ends of said plate into attachment to said attachment structures.

2. Device according to claim 1 wherein the plate comprises two parts of identical lengths or not, said two parts being joined together by a joining part that is located in an inner part of the plate at a sufficient distance from the ends of said plate to enable the attachment of the plate onto two implants wherein one implant is disposed on either side of said joining part.

3. Device according to claim 2 wherein the joining part is located in a position offset with respect to the center of the plate length.

4. Device according to claim 1 wherein the plate has an “

H”

or “

h”

shape.

5. Device according to claim 1 wherein the plate has at least one longitudinally elongated opening having a first region that is of substantially constant width and a second region that is larger in size than the first region, said opening being so sized as to embrace the attachment structure of an implant before sliding to bring said attachment structure into the first region.

6. Device according to claim 1 wherein the plate is joined to at least one implant by an attachment structure that is able to hold said plate without preventing the implant from rotating about its screwing axis, or without preventing a specified clearance of the plate with respect to the implant, or both;

whereby enabling continued screwing of the implant, or adjusting of the position of the plate, or both, after the plate has been assembled on the implant.

7. Device according to claim 1 wherein at least one implant has an elongated shape around an implant axis, and comprises a first bone anchoring, threaded end and a second end with an elongated part that is adapted to pass through a plate support, wherein said plate support is substantially freely rotatable around said elongated part, and wherein said elongated part has a clamp that is sufficient to clamp the plate (2) against said plate support.

8. Device according to claim 1 wherein the elongated clamping support of the implant is mobile with respect to the rest of the implant, through a universal joint between a screw head part of the implant and a part of the clamping support head, whereby enabling continued screwing of the implant after the plate has been assembled on the implant, by rotating the clamping support around a clamping support axis, when said axis forms a non-null angle with the axis of the implant.

9. Device according to claim 1 wherein the plate is adapted to at least partially surround the clamping support or the second end of the implant and is adapted to rests on a surface of its complementary plate support, said plate support having, on the implant sides a concave surface in the form of a spherical portion which is supported in a complementary fashion on the outer surface of the implant screw head.

10. Device according to claim 1 wherein the clamping support (12) has a first elongated end along the support axis a second end bearing the support head, said support head having a non-circular cross-section having at least one concave part and comprising at least one dimension that is greater than at least one cross-section of the first end of the clamping support said support head having firstly one section that is substantially partly circular along a plane including the support axis, and being secondly arranged in the screw head inside a housing wherein the inner surface has at least one projecting part cooperating with the concave part of the support head to prevent rotation of the clamping support around its axis.

11. Device according to claim 10 wherein the inner surface of the screw head housing has a shape that is substantially complementary to the outer surface of the support head.

12. Device according to claim 8 wherein the housing receiving the support head has, on the side of said clamping head, a specified dimension that is sufficient to allow the clamping support a clearance along a specified angle, between the axis of the clamping support and the axis of the implant, without said clamping support escaping from said housing.

13. Device according to claim 8 wherein the clamping support head has a star shaped cross-section with rounded ends, along a plane perpendicular to the support axis.

14. Device according to claim 8 wherein the clamping support clamping means comprise a threading cooperating with a nut to hold or clamp the plate against the plate support.

15. Device according to claim 8 wherein the clamping support comprises, at its end opposite the implant, an inner or outer recess adapted to receive a rotational drive tool that enables further screwing or clamping of the implant in the vertebrae.

16. Device according to the claim 1 wherein said at least one implant has a first bone anchorage end that has a longitudinal bore concentric to its outer surface, said, bore communicating with space outside said outer surface through at least one bone fusion opening disposed in a wall between said inner bore and said outer surface;

thus enabling a fusion between the bone substance inside and the bone substance outside of the first end.

17. Device according to claim 16 wherein the first bone anchorage end of at least one implant has two threadings that are adapted to wind in the same direction during the screwing of the implant, wherein said threadings are disposed respectively, on the outer surface of said first end and on the inner surface of the bore that it comprises.

18. Device according to claim 1 further comprising at least one bone fusion opening in said implant that has the shape of a longitudinal oblong hole.

19. A method for preassembling a device according to claim 1 comprising the following steps:

assembling a plate support on a clamping support member of an implant; and

assembling the nut on an external threading of a clamping support of said implant.