DE202017001604U1 - implant - Google Patents

Abstract

Implant for insertion between the vertebral body (1) of the spinal column, wherein the implant (4, 14) at least one in the direction of adjacent vertebrae (1) facing, preferably continuous recess or opening (12) and in a plan view in a built-in position a portion of a Half of the intervertebral space (3) between two adjacent vertebral bodies (1) covering, characterized in that the implant (4, 14) on its to the exterior of the intervertebral space (3) facing side surface (9) in plan view has a convex curvature.

Description

The present invention relates to an implant for insertion between vertebral bodies of the spine, wherein the implant has at least one facing in the direction of adjacent vertebrae, preferably continuous recess or opening and in a plan view in a built-in position a portion of one half of the intervertebral space between two adjacent vertebral bodies covers.

Such an implant is for example the U.S. Patent 4,834,757 in each case substantially implants having a rectangular cross-section are provided, which are inserted posteriorly between in each case two adjacent vertebral bodies in both lateral regions or halves of the intervertebral space. A disadvantage of this known embodiment, which is commonly referred to as a PLIF implant or PLIF cage, is in particular that these implants are relatively narrow and thus have a narrow contact surface. By providing cuboid structures having a substantially rectangular cross-section, such implants do not correspond to the natural anatomy of the vertebral bodies or the intervertebral space, in particular in the middle part of the vertebra or vertebral body, which is spongy and thus not as hard as the rim - or outdoor area. In this way, in particular supported by the rectangular and thus formed with sharp edges or corners shape of such an implant, this penetrate into the softer region of the vertebral bodies or sink. In addition, a tilting and thus a displacement is possible in particular by the narrow rectangular shape.

The present invention aims to modify an implant of the type mentioned above, which in each case covers a partial area of one half of a vertebral body in a built-in position, so that two implants each are arranged between adjacent vertebral bodies in such a way that the disadvantages of the above-mentioned prior art be avoided or at least reduced, and in particular to provide an implant for insertion between the vertebral body of the spine, with which a more reliable and secure support between the adjacent vertebral bodies can be provided in particular in adaptation to the anatomical conditions.

To achieve these objects, an implant of the type initially mentioned is essentially characterized in that the implant has a convex curvature on its side face facing the exterior of the intervertebral space in plan view. Due to the fact that, according to the invention, the implant has a convex curvature on its side face facing the exterior of the intervertebral space, it is possible with the implant according to the invention, in accordance with the anatomical conditions, in contrast to the known state of the art, where essentially rectangular external dimensions implants are proposed the vertebral body or the intervertebral space to arrange an implant in each case a half of the vertebral body, whose outer side or boundary surface substantially follows the arcuate outer contour of the vertebral body. By providing such a curved or arcuate outer side or boundary surface, moreover, the support surface of the implant between adjacent vertebral bodies in adaptation to the anatomical conditions is increased and thus the force acting per unit area or to be absorbed accordingly reduced. Furthermore, by avoiding structures having a rectangular cross-section, sinking in the middle region of the vertebral bodies can be avoided, since the outer convexly curved side surface makes it possible to support the implant in edge regions of the vertebral bodies which produce a correspondingly harder structure Make available.

In a further adaptation to the anatomical conditions and to improve the supporting effect on particular greater hardness or strength having edge regions of the vertebral bodies is proposed according to a preferred embodiment that the convex curved side surface is at least partially simulated the course of the Apophysenrings. In this way, not only can a reliable positioning of the implant corresponding to the shape or contour of the apophysis ring be made available, whereby a displacement or slippage is prevented or prevented, but it takes place over a large area and a support of the implant to a larger Hardness or strength having edge regions of the vertebral bodies.

In addition, it is proposed according to a further preferred embodiment that the implant has at its ends a reduced height relative to the central region. This can take into account the fact that the vertebral bodies are usually spaced further apart in their central region than in the outer peripheral regions. By such a shaping of the implant, the mobility of the spine with built-in implants can thus be maintained or reliably reproduced in accordance with the natural anatomical conditions.

For a simple introduction of the implant into the intervertebral space during implantation, it is also proposed that at least one end of reduced height has a flattened or slightly conically tapered shape relative to the free end, as corresponds to a further preferred embodiment of the implant according to the invention.

In addition to a preferably greater height in the middle region in adaptation to the anatomical conditions, as mentioned above, it is provided according to a further preferred embodiment that the implant is formed in its central region on at least one directed to a vertebral body cover surface with a convex curvature , By such an additional convex curvature on at least one top surface of the implant anatomical conditions can be better taken into account and the mobility of the spine in the installed state of the implants are supported accordingly. An adaptation to the partially different shapes or boundary surfaces of the vertebral bodies can be provided by virtue of the fact that a cover surface has essentially a flat or planar design, while the second cover surface is correspondingly convexly curved or arched. For use in special intervertebral spaces, however, it can be provided according to the invention that both cover surfaces have a convex curvature or curvature which, if appropriate, have different radii of curvature corresponding to the intended use.

For a simplification of the positioning and to facilitate insertion, it is moreover proposed that the ends of reduced height are formed on their surfaces facing the adjacent vertebral bodies with a smooth surface, as corresponds to a further preferred embodiment of the implant according to the invention.

Also, in support of the anatomically predetermined curvature of the spine and to maintain the biomechanics thereof, it is proposed that the adjoining adjacent vertebral bodies cover surfaces of the implant with each other form an acute angle, the height of the implant at the end facing the spinous process is less than the height at the to the interior of the vertebral body turned end, as corresponds to a further preferred embodiment of the implant according to the invention.

To support a connection with the surrounding bone material or when growing together with the bone material and also for secure and reliable positioning, it is proposed according to a further preferred embodiment that the implant be porous in a manner known per se at least on its cover surfaces facing the adjacent vertebral bodies and / or is formed with a profiling, in particular a plurality of elevations and depressions.

For a further support of a connection with the surrounding bone material or to facilitate an adhesion with the surrounding material is also proposed that in a conventional manner, the implant has at least one recess or aperture at the boundary surface facing the interior of the vertebral body.

If insertion of a material into the interior of the implant should be provided, and in particular to support a connection with surrounding material as well as for coalescence with the same, it is proposed according to a further preferred embodiment that the interior of the vertebral body facing recess or opening is conically widening outwardly or funnel-shaped widening.

For a reliable positioning of the implant and / or an optionally planned introduction of a material into the implant after positioning in the intervertebral space is proposed according to a further preferred embodiment that the implant at least one end with a passage opening for fixing a tool for inserting the implant and / or for the arrangement of a particular tubular cannula for introducing a material into the interior of the implant is formed. Such a passage opening, which may for example be provided with a thread, can either serve for fixing a tool for positioning the implant in the intervertebral space or can additionally or alternatively be used for the arrangement of, for example, a tubular cannula for introducing a material into the interior of the implant. Thus, in contrast to the known prior art, it is not necessary to arrange, for example, bone mass in the cavity of the implant prior to introduction of the implant into the intervertebral space, which can partially escape into the intermediate space, for example due to high mechanical stresses during insertion of the implant, and thus the desired coalescence with the surrounding material can not support accordingly. In an inventively provided filling of the cavity of the implant after positioning or securing in the installed position in the intervertebral space, a reliable backfilling of the cavity of the implant succeeds, whereby subsequently an ingrowth is facilitated or supported with surrounding material. For example, bone cement can be introduced into the interior of the cavity of the implant in the installed state in order, for example, to allow additional support function or additional connection with the surrounding bone material in the case of brittle bone material.

The invention will be explained in more detail with reference to embodiments schematically illustrated in the accompanying drawings. In this show:

1 a schematic partial side view of two adjacent vertebral bodies, between which in each case two, substantially half of the intervertebral space covering or overlapping implants are used;

2 a schematic plan view of one of the vertebral bodies, wherein the positioning of the implants according to the invention is indicated;

3 a schematic rear view of the two vertebral bodies according to the arrow III of 1 and 2 , from which the positioning of two implants in the disc space can be seen; and

4 on an enlarged scale, a side view of a modified embodiment of an implant according to the invention.

In 1 are schematic with 1 denotes two adjacent vertebral bodies, each with spinous processes or spinous processes 2 are formed. In the intervertebral space or intervertebral space 3 are implants after removing an intervertebral disc 4 used, as will be discussed in detail below.

From the illustration according to 1 it can be seen that the implant is at its ends 5 one each over a middle area 6 having reduced height or thickness. The top surfaces 6 show at the in 1 illustrated embodiment in each case a convex curvature, wherein from 1 it can be seen that the curvature or curvature of the top surfaces 6 essentially the anatomical conditions in the area of the boundary surfaces 7 corresponds to the vertebral body, allowing optimal support of the adjacent vertebral body 1 through the implants used 4 becomes possible.

From the illustration according to 2 it can be seen that the implants 4 each part of a half of the intervertebral space 3 the adjacent vertebral body 1 cover. While the implants 4 in the area facing the center, a substantially flat boundary surface 8th is at the outside of the vertebral body 1 side facing a convex curve having side or boundary surface 9 intended. This side surface 9 In its curvature corresponds essentially to the course of the Apophysenrings 10 or arrives in built-in position substantially in abutment with the Apophysenring 10 , Due to the convex curved or curved side or boundary surface 9 Thus, not only an enlargement of the support surface of the implants 4 provided, but it is in particular a support on the convex curved side or boundary surface 9 in the area of the outer edge of the vertebral bodies 1 in contrast to the prior art possible, in which substantially rectangular outer contours implants were used, which corresponding in the middle and a softer state having area of the vertebral bodies 1 were arranged.

Out 1 and 2 it can be seen that the implants 4 not just on the outwardly facing surfaces an opening or opening 11 but that in particular to the adjacent vertebral bodies 1 attired deck surfaces 6 at least one opening or opening 12 is provided which promotes or facilitates coalescence with the adjoining material in the installed position.

From the schematic representation according to 3 In addition, it can be seen that the implants 4 are each arranged substantially symmetrically and a portion of a half of the intervertebral space 3 cover.

In 3 It also indicates that the implants 4 an opening at one end surface 13 which, for example, for handling the implant 4 can be used by a tool during insertion. Alternatively or additionally, over the opening 13 for example, by using a cannula material in the internal cavity of the implant 4 be inserted in a built-in position. Such a material may favor ingrowth with the surrounding bone material in a built-in position or be formed, for example, by a bone cement to achieve solidification.

From the illustration according to 3 It is also evident that the implants 4 on its side facing or boundary surface 8th have a greater height than at the outwardly directed boundary surface 9 to as well as the anatomical conditions of the intervertebral space 3 correspond to.

While in one embodiment according to 1 the top surfaces 6 each a convex Curvature in adaptation to the intervertebral space 3 is at the in 4 illustrated modified embodiment of an implant 14 provided that a top surface or boundary surface 15 is substantially flat or flat, while the second top surface or boundary surface 16 again has a convex curvature or curvature. In the presentation according to 4 In addition, it is indicated that the top surfaces 15 and 16 a profiling or porous surface 17 to promote coalescence with adjoining material in a built-in position.

Furthermore, in the embodiment according to 4 provided that to the interior or to the spinous processes 2 clever partial area 18 a greater height than the opposite end portion 19 having both ends 18 and 19 having a reduced height compared to the central region. Furthermore is in 4 shown that the end areas 18 and 19 unlike the top surfaces 15 and 16 have a substantially smooth surface so as to facilitate insertion. In addition, the end area 18 with an additional rejuvenation or flattening 22 provided to further facilitate insertion.

Due to the different height of the end areas 18 and 19 and thus an acute angle between the top surfaces 15 and 16 a further adaptation to the anatomical conditions and in particular the curvature of the spine is achieved.

In 4 is beyond an opening 20 in a side surface an opening or opening 21 indicated, which in turn, for example, for handling the implant 14 can be used with a tool. Alternatively or additionally, in particular in a built-in position over the opening 21 for example, by a non-illustrated cannula filling the cavity of the implant 14 be performed to a subsequent ingrowth of the implant 14 to favor or support.

At the opening or opening 20 in the side surface of the implant 14 is also indicated that the opening widens funnel-shaped or conical.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• US 4834757 [0002]

Claims (11)

Implant for insertion between vertebral bodies ( 1 ) of the spine, with the implant ( 4 . 14 ) at least one in the direction of adjacent vertebral bodies ( 1 ) facing, preferably continuous recess or opening ( 12 ) and in a plan view in a built-in position a portion of a half of the intervertebral space ( 3 ) between two adjacent vertebral bodies ( 1 ), characterized in that the implant ( 4 . 14 ) at its exterior to the intervertebral space ( 3 ) facing side surface ( 9 ) has a convex curvature in plan view. Implant according to claim 1, characterized in that the convexly curved side surface ( 9 ) at least partially the course of the Apophysenrings ( 10 ) is modeled. Implant according to claim 1 or 2, characterized in that the implant ( 4 . 14 ) at its ends ( 5 . 18 . 19 ) has a reduced height compared to the central region. Implant according to claim 3, characterized in that at least one end ( 18 ) reduced height a flattened or slightly conically tapered to the free end shape ( 22 ) having. Implant according to one of claims 1 to 4, characterized in that the implant ( 4 . 14 ) in its central region on at least one of a vertebral body ( 1 ) directed deck surface ( 6 . 16 ) is formed with a convex curvature. Implant according to one of claims 3 to 5, characterized in that the ends ( 5 . 18 . 19 ) reduced height at their adjacent vertebral bodies ( 1 ) directed surfaces are formed with a smooth surface. Implant according to one of claims 1 to 6, characterized in that the adjacent vertebral bodies ( 1 ) adjacent deck surfaces ( 15 . 16 ) of the implant ( 14 ) at an acute angle with the height of the implant at the end facing the spinous process ( 19 ) less than the height at the end facing the interior of the vertebral bodies ( 18 ). Implant according to one of claims 1 to 7, characterized in that the implant ( 4 . 14 ) in a manner known per se at least at its to the adjacent vertebral bodies ( 1 ) facing deck surfaces ( 6 . 15 . 16 ) is formed porous and / or with a profiling, in particular a plurality of elevations and depressions. Implant according to one of claims 1 to 8, characterized in that in a conventional manner the implant ( 4 . 14 ) at the interior of the vertebral bodies ( 1 ) facing boundary surface ( 8th ) at least one recess or opening ( 11 . 20 ) having. Implant according to claim 9, characterized in that the interior of the vertebral bodies ( 1 ) facing recess or opening ( 20 ) is conically widening or funnel-shaped widening outwards. Implant according to one of claims 1 to 10, characterized in that the implant ( 14 ) at least one end ( 19 ) with a passage opening ( 21 ) for determining a tool for inserting the implant ( 14 ) and / or for the arrangement of a particular tubular cannula for introducing a material into the interior of the implant is formed.

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