WO2010045901A1

WO2010045901A1 - Implant for insertion between vertebral bodies of the spinal column

Info

Publication number: WO2010045901A1
Application number: PCT/DE2008/001721
Authority: WO
Inventors: Erich Kast
Original assignee: Ulrich Gmbh & Co. Kg
Priority date: 2008-10-24
Filing date: 2008-10-24
Publication date: 2010-04-29
Also published as: EP2320833A1; MX2009013311A; CN101808597A; TW201021774A; CN101808597B; TWI465228B

Abstract

The invention relates to an implant for insertion between vertebral bodies (8) of the spinal column as a spacer for vertebrae or vertebrae portions removed from the spinal column, comprising a first implant part (2) and a second implant part (3), which can be moved relative to each other in the direction of the coaxial longitudinal axis thereof for changing the length of the implant (1), and further comprising at least one fixing plate (10), which can be fastened to one of the implant parts (2, 3), is oriented toward the adjoining vertebra and covers the same at least partially. The fixing plate (10) is formed by a vertebra contact plate (11) and a base plate (12) projecting therefrom and having a guide rail (13), said base plate being used for radially adjusting the fixing plate (10) with respect to the one implant part (2, 3), wherein the one implant part (2, 3) is associated with means for radially fixing the base plate (12).

Description

Implant for insertion between vertebral bodies of the spine

The invention relates to an implant for insertion between vertebral bodies of the spine as a placeholder for vertebrae or vertebrae removed from the vertebral column, with a first implant part and a second implant part, which are adjustable in the direction of their coaxial longitudinal axis to change the length of the implant, and with at least one one fixable to the implant parts, facing the adjacent vortex and this at least partially overlapping fixing plate.

Such an implant is known from EP 0 950 388 A2. This implant consists of a total of three implant parts, namely two terminal, intended for engagement with the adjacent vertebra terminal implant parts and a central intermediate implant part therebetween, which are connected to each other via threads. Holes are formed in the terminal implant parts which primarily serve to allow access to the interior of the implant parts for introducing bone cement or bone material. These holes are additionally used to be able to attach a fixation plate with a circular collar optionally to a terminal implant parts, for which purpose in the collar openings are formed, with two holes formed in the terminal implant part to cover can be brought. Through the openings bolts can be inserted into the holes. The fixing plate has a slot in the longitudinal direction, which is adjustable in its width, so that a clamping of the bolts is achieved in the holes. As a result, the fixation plate is attached to the outer periphery of the terminal implant part and can be used to improve the stability of the spine without preventing accessibility to the implant parts.

A disadvantage of this known implant, however, is that this with the increasingly use of finding minimally invasive surgery

Restrictions is subject to because the change in length of the implant, the central implants relative to the terminal implant parts by applying a tool to be moved in a circular arc and adjustment by the arrangement of the fixation plate on the outer circumference of the terminal implant parts to the individual circumstances of the patient is not possible ,

The invention is therefore based on the object, an implant of the type mentioned in such a way that the position of the fixing plate relative to the implant is variable.

This object is achieved in an implant of the type mentioned according to the invention in that the fixing plate is formed by a swirl bearing plate and a protruding from this, the radial adjustment of the fixing plate relative to the implant part serving base plate with a guide rail, and that the one implant part Means are assigned for radial fixing of the bottom plate.

This implant is characterized in that a different distance of the vertebral investment plate to the center of the implant part adjustable is and thus a different placement of the implant between the vertebral bodies is possible without having to give up the use of the fixation plate. The advantage of greater variability is combined with the advantage of improved stability, since the radial adjustability of the fixation plate with the vertebral bearing plate relative to the implant part can be terminated by the means for radially fixing the bottom plate. It is very particularly preferred in the context of the invention if each of the two implant parts each have a fixing plate is assigned, since so a further improved stability is achieved.

It has furthermore proved to be advantageous if the implant part has an end plate facing the adjacent vertebra with an opening for receiving a clamping means engaging the bottom plate, since this will overcome a restriction on the circumference of the implant part for connection to the fixation plate. With regard to the simplicity of the structure and ease of operation by the surgeon, it is expedient if the opening is designed as a threaded bore and the clamping means as a clamping screw.

A good guidance of the bottom plate relative to the face plate, it is designed that the bottom plate is like a fork with at least two forks, in which attack the means for fixing. It is of course possible to provide more than two forks, so that in terms of increased variability and the means for fixing with different pairings of forks can interact, so the fixing plate can be adjusted in their lateral orientation relative to the implant part.

A particularly strong connection is used when the forks under the screw head of the clamping screw cross clamping webs. An improved adaptation to the anatomical conditions makes it possible for the turbulence plates to have a convex cross-section, at least one screw opening and a window in the region of the connection to the bottom plate. The screw opening is for

Recording a bone screw, in particular an expansion designed, through which an additional securing the fixation plate against the vertebral body is achieved. The window in the fixation plate serves primarily to allow visual inspection in the area behind the vortex plate.

In order to achieve a better mechanical connection between the vertebral body and the implant, the bottom plate has on the side facing the adjacent vortex at least one anchoring mandrel.

In the context of the invention, furthermore, if the first implant part and the second implant part are designed as tubular sleeves, the first implant part is assigned a rotatable threaded ring with a toothing which engages with a ring thread in a thread associated with the second implant part in that a threaded bore is formed in the wall of the first implant for inserting a surgical instrument serving for twisting the threaded ring. The design and the interaction of such first and second implant parts with a surgical instrument is basically known from EP 1 219 266 A1, wherein this implant described therein and therefore not further explained here is suitable for the embodiment according to the invention using the radially adjustable fixation plate and thus overall a minimally invasive procedure is possible. In order to make a determination of the fixing plate relative to the implant part not necessarily after analyzes of the anatomical conditions before the operation ex situ, there is a possibility that tool holders are formed on the screw head for rotating the clamping screw, so that through the window access to the screw head exists and the clamping screw can also be tightened in situ stronger. It is advantageous that the window and the threaded hole are pointing towards the same side.

It has also proven to be advantageous if between the bottom plate and the end plate locking seats are formed, which allow a primary position securing the fixing plate relative to the implant part before the final position assurance is done by tightening the clamping screw. Conveniently, the locking seats are formed by transverse to the radial adjustment direction of the guide rail extending webs.

In the following the invention will be explained in more detail in an embodiment shown in the drawing; show it:

2 shows a perspective view of the upper part of the implant with the fixation plate in a first radial position, FIG. 3 shows a perspective view of the upper part of the implant with the fixation plate in one 4 shows a perspective view of the implant from FIG. 3 from a different view,

5 shows a representation of the implant from FIG. 4 in a lateral perspective, 6 shows a side view of the implant according to the invention in situ between two vertebral bodies of the spinal column, and FIG. 7 shows the detail VII from FIG. 6.

1, an implant 1 is shown, which serves for insertion between the vertebral body 8 of the spine as a placeholder for vertebrae or vertebrae removed from the vertebral column. This implant 1 consists of a first implant part 2 and a second implant part 3, which are adjustable in the direction of their coaxial longitudinal axis to change the length of the implant 1 against each other. This adjustability is achieved by designing the first implant part 2 and the second implant part 3 as tubular sleeves, the first implant part 2 comprising the second implant part 3 on the outside, with a rotatable threaded ring 4 assigned to the first implant part 2, which engages on its inner peripheral surface Has ring thread, with which this engages in a second implant part 3 associated thread 5. On the outer peripheral surface of the threaded ring 4 is provided with a toothing 6, in particular a bevel gear, so that the length change in terms of distraction of the vertebral body 8 can be achieved by a rotation of the threaded ring 4 by means of a screwed into a threaded bore of the first implant part 2 surgical instrument.

These implant parts 2, 3 have an end plate 9 facing the adjacent vertebra with an opening. This end plate 9 is used for releasably securing a fixable to the respective implant part 2, 3, facing the adjacent vortex and this at least partially overlapping fixing plate 10 by a vortex contact plate 11 as a projecting from this, the radial adjustment of the fixing plate 10 opposite the bottom part 12 serving for the implant part 2, 3 is formed with a guide rail 13. at In the exemplary embodiment illustrated in FIG. 1 and FIG. 6, each of the two implant parts 2, 3 is assigned the fixation plate 10 which can be fixed to the respective implant part 2, 3 by means of fixing the bottom plate 12, these means being shown in FIG Embodiment by a designed as a threaded hole opening of the end plate 9 to be screwed clamping screw 14 are designed. As can be seen in particular from Figure 4, the bottom plate 12 is like a fork with two forks 15 designed to which the clamping screw 14 acts, namely under the screw head 7 of the clamping screw 14 projecting clamping webs 16. Alternatively, it is in the sense of a kinematic reversal course conceivable to provide the bottom plates 12 with a web which is inserted between forks of the end plate 9, in particular in the manner of a dovetail guide. To adapt to the rounding of the vertebral body 8, the turbulence plate 11 is convex in cross section and further has

Screw holes 17 through which bone screws 18 can be performed. FIG. 5 shows that, in the region of the connection to the base plate 12, the whirl bearing plate 11 has a window 19 which permits a control of the area behind the whirling plate 11 and at the same time opens up the possibility of guiding a tool or instrument through the window 19.

As can be seen in particular from Figures 2 to 4, the bottom plate 12 has on the side facing the adjacent vortex a plurality of anchoring mandrels 20, which can penetrate into the vertebral body 8 and thus effect a positional backup before the bone screw 17 to be inserted through the bone screws 18, which are preferably designed as expansion screws, are placed. To use the implant 1 according to the invention, the required position of the fixation plate 10 relative to the implant parts 2, 3 is determined more suitably by means of an imaging procedure and the fixation plate 10 is securely mounted on the implant part 2, 3 in preparation for the operation. During the operation, by means of the surgical instrument to be inserted into the threaded bore, the distraction of the implant 1 to obtain the required height can then be carried out, in order then to carry out the final fixation of the implant 1 by means of the bone screws 18. This results in a very stable connection, in particular their angular stability achieved by the bone screws 18 is to be mentioned.

If an ex situ fixation of the position of the fixation plate 10 with respect to the implant part 2, 3 is not possible, the actuation of the clamping screw 14 is made more difficult since it is not accessible in situ by the vertebral body 8 from the axial direction. A principal operation remains possible by means of an access option through the window 19. According to an embodiment not shown in the drawing is provided for this application that 9 locking seats are formed between the bottom plate 12 and the end plate by transverse to the radial adjustment direction of the guide rail 13 extending webs ,

LIST OF REFERENCE NUMBERS

1 implant

2 first implant part

3 second implant part

4 threaded ring

5 threads

6 toothing

7 screw head

8 vertebral bodies

9 face plate

10 fixation plate

11 vortex plate

12 base plate

13 guide rail

14 clamping screw

15 forks

16 clamping bar

17 screw opening

18 bone screw

19 windows

20 anchoring mandrel

Claims

claims:

1. implant for insertion between the vertebral body (8) of the spine as a placeholder for the vertebral column removed vertebrae or vertebrae, with a first implant part (2) and a second implant part (3) in the direction of its coaxial longitudinal axis to change the length of the implant (1 ) are mutually adjustable, and with at least one on one of the implant parts (2, 3) attachable, facing the adjacent vortex and this at least partially covering

Fixation plate (10), characterized in that the fixation plate (10) by a Wirbelanlageplatte (11) and a projecting from this, the radial adjustment of the fixing plate (11) relative to the one implant part (2, 3) serving bottom plate (12) with a Guide rail (13) is formed, and that the one implant part

(2, 3) are assigned means for radially fixing the bottom plate (12).

2. Implant according to claim 1, characterized in that each of the two implant parts (2, 3) is associated with a respective fixing plate (10).

3. Implant according to claim 1 or 2, characterized in that the implant part (2, 3) has a the adjacent vortex assigning end plate (9) having an opening for receiving a on the bottom plate (12) engaging clamping means.

4. Implant according to claim 3, characterized in that the opening is designed as a threaded bore and the clamping means as a clamping screw (14).

5. Implant according to one of claims 1 to 4, characterized in that the bottom plate (12) is fork-shaped with at least two forks (15), on which attack the means for fixing.

6. Implant according to claim 5, characterized in that the

Forks (15) under the screw head (7) of the clamping screw (14) cross clamping webs (16).

7. Implant according to one of claims 1 to 4, characterized in that the bottom plate (12) is provided with a web for insertion

Forks of the front plate (9).

8. Implant according to one of claims 1 to 7, characterized in that the Wirbelanlageplatte (11) is convex in cross-section, at least one screw opening (17) and in the region of the connection to the bottom plate (12) has a window (19).

9. Implant according to one of claims 1 to 8, characterized in that the bottom plate (12) has on the side facing the adjacent vortex at least one anchoring mandrel (20).

10. Implant according to one of claims 1 to 9, characterized in that the first implant part (2) and the second implant part (3) are designed as tubular sleeves, that the first implant part (2) has a rotatable threaded ring (4) with a toothing is associated, which engages with a ring thread in the second implant part (3) associated thread (5), and in that in the wall of the first implant part (2) has a threaded bore for inserting a rotation of the threaded ring (4) serving surgical instrument.

1 1. Implant according to one of claims 4 to 10, characterized in that on the screw head tool holders for rotating the clamping screw (14) are formed.

12. Implant according to claim 10 or 1 1, characterized in that the window (19) and the threaded bore are pointing towards the same side.

13. Implant according to one of claims 3 to 12, characterized in that between the bottom plate (12) and the end plate (9) locking seats are formed.

14. Implant according to claim 13, characterized in that the locking seats are formed by transverse to the radial adjustment direction of the guide rail (13) extending webs.