DE202012006162U1 - Intervertebral implant for insertion between adjacent vertebral bodies - Google Patents

Abstract

Intervertebral implant with supporting surfaces (3) that can be placed on adjacent vertebral bodies and a cuboid basic shape with structuring on the contact surfaces to the vertebral bodies, characterized in that the implant has a bow-shaped cross section in the sagittal section plane with bow (2, 2 '), a slot (7) and has a spring element (4) and anterior-cranial and anterior-caudal stops (5, 6) against displacement.

Description

The invention relates to an intervertebral implant for insertion between adjacent vertebral bodies with the features of the preamble of claim 1.

It is known that in the human anatomy of the spine, especially in the natural form of the spine, changes can occur. Thus, inter alia, degenerative intervertebral disc disorders reduce the distance between two vertebral bodies. This is accompanied by a reduction of the dorsal nerve root canals. Progressively, this leads to impairment of the nerve roots and pain to dysfunction. The therapy goal is the elimination of pain. The condition for this is the restoration of the joint gap height between two vertebrae.

Various intervertebral implants are known or cages are implanted for stiffening. For example, intervertebral disc implants are used for mobilization and height recovery.

The disadvantage is that the stiffening is too restrictive for many patients. Mobilization is associated with a sense of instability for many patients.

As a further variant known U-bow-shaped titanium implants with spring action. These allow the freedom of movement for nodding (anterior flexion). The lateral bending (lateral flexion), however, is not supported. The spring effect is very low. So is also in the DE 44 16 605 C1 an intervertebral implant is described, in which the support surfaces are formed by the outer sides of the substantially mutually parallel legs of a U-shaped support body.

The object of the invention is to form an intervertebral implant of the type mentioned so on that it has spring properties and the freedom of movement for nodding (anterior flexion) is given and at the same time the lateral bending (lateral flexion) in the supplied segment is not possible.

This object is achieved by the characterizing features of claim 1. Further advantageous embodiments will be apparent from the dependent claims.

It has been shown that the intervertebral implant according to the invention represents a bow-shaped cross section in the sagittal plane with a resilient U-bracket.

The support surfaces of the stirrups have the size of the vertebral body cover plates. The contact surface (support surface) is dimensionally stable during the intended inferior-retro-flexion (lordosis and kyphosis). The implant according to the invention has at least one anterior stop for safety against slipping in the dorsal direction. In a preferred variant, anterior stops are arranged on each bracket.

Between the anterior-cranial and anterior-caudal straps there is a slit that runs from ventral to dorsal. The slot is lateral to lateral over the entire width of the implant. From ventral to dorsal, however, the slot has only a certain length and thus a certain depth in the implant, so that a bridge connects the two brackets. The formal slot in the cross section of the sagittal plane may vary depending on the conditions that are required. The shape can be a simple straight slot, but can also be curved, wavy or stepped. Also, several forms combined with each other are possible and are not intended to limit the invention.

According to the invention, a breakthrough from lateral to lateral is present at least in one stirrup. The breakthrough is arranged so that between the opening and the slot, a spring-like element is formed, which can be referred to as a spring element. Advantageously, the breakthrough in the direction of dorsal is longer than the slot, so that the breakthrough still extends behind or until the slot. This conditionally creates a kind of leaf spring, which allows the desired spring action with a certain spring force. This spring element preferably has a curved shape. The surface of the spring element may be smooth, but it is also possible a different surface, for example a structured surface, so that the spring element has certain properties in a bend.

The breakthrough may also have different shapes in cross-section in the sagittal plane. This can be straight, but also bent, wavy, stepped, kinked or the different shapes are combined.

Since the object according to the invention is U-shaped in the sagittal plane, it has two stirrups. The support surfaces of the stirrups, which are the contact surfaces to the adjacent. Vertebrae represent preferred structured. Preferably with a kind of tooth structure. The tooth structure is designed so that from dorsal in the ventral direction several times an increase of the surface is recorded, which drops sharply on the dorsal side to then rise again. This can be done over the entire width, but preferred is an increase in several blocks across the width. This tooth structure is particularly important so that the implant is not forced out of its position between the vertebral bodies. The invention should not be limited thereby. It can also be ribs, tips, fins or a combination of these.

According to the invention, anterior stops on the brackets are additionally present so that slipping is prevented in the dorsal direction.

On the dorsal side, the intervertebral implant according to the invention may have various shapes, according to the required conditions. For example, the dorsal closure can form a plane from lateral to lateral and thus have a curved shape from cranial to caudal. But it may also be straight from the cranial to the caudal and, for example, a corrugated form may be present in the lateral extension. Other shapes are possible.

The implant according to the invention preferably consists of a material which does not contain artifacts in the CT, MRI u. a. in image studies, such as plastics, for example PEEK. However, this is not intended to limit the invention, since other biocompatible materials are possible.

So that the position of the implant used can be determined, for example, by X-ray, one or more openings are present in the intervertebral implant in which X-ray contrast agents can be introduced.

Preferred indication of the implant according to the invention in the spinal column is between the vertebrae C5 / C6 and C6 / C7.

Further advantages, details and inventive features will become apparent, for example, from the following detailed explanations of the invention with reference to the accompanying drawings.

Show it:

1a Overall view of the intervertebral implant oblique from the direction of lateral cranial with a straight dorsal termination.

1b Overall view of the intervertebral implant oblique from the direction lateral-cranial with corrugated dorsal completion.

2 View of the intervertebral implant in cross section in the sagittal plane.

3 Top view of the intervertebral implant from cranial.

4 View of the implant from the dorsal direction.

Subsequently, the same parts are provided with the same reference numerals.

In 1a is an intervertebral implant obliquely from lateral-cranial direction with straight dorsal termination 11 , As can be seen, the dorsal conclusion 11 curved in the lateral extension straight and in the cranial-caudal extension. Good to see are the two brackets 2 . 2 ' and the slot located therebetween 7 , In the temple 2 is the breakthrough 9 arranged on the dorsal side longer than the slit 7 is. As a result, the spring element is formed 4 out. On the support surface 3 are in this example three rows with multiple teeth 8th arranged.

In the 1b a similar intervertebral implant is shown, except that the dorsal closure 11 another is. In this example, the surface is curved from cranial to caudal, straight and lateral.

In the 2 is that in the 1a seen intervertebral implant in cross section in the sagittal plane. The U-shaped intervertebral implant 1 with his two temples 2 . 2 ' and the slot between them 7 which is open in the implant in the lateral and anterior directions.

In the temple 2 is the breakthrough 9 , which is longer in the dorsal than the slit 7 , Because of the breakthrough 9 dorsally longer than the slot 7 is, he is in the end still partially in front of the slot 7 arranged. The arrangement results in the spring element 9 , Good to see is the anterior-cranial stop 5 and the anterior-caudal stop 6 , From the cross section can also be seen that the support surfaces 3 . 3 ' are not exactly arranged in parallel but slightly diverge in anterior direction. Due to this, a clamping effect is achieved because during implantation, the intervertebral implant is slightly compressed and this would then go back to the starting position. This alone creates a tight fit. So that the intervertebral body is not pushed too much into the spinal column during the operation or later can not migrate into the resilient movements, are the anterior-cranial stop 5 and the anterior-caustic stop 6 at the end of the hanger 2 . 2 ' arranged. At the support surfaces 3 are the arranged teeth 8th shown. Also the opening with the X-ray food latch 10 can be seen.

The 3 shows the intervertebral implant in the plan view of cranial. Good to recognize here is the cuboid shape of the implant with his teeth 8th , These teeth 8th are arranged in three blocks in this example.

The 4 shows the view of the implant from the dorsal direction. Shown are the teeth 8th in rows of teeth on the support surfaces 3 at the temple 2 and at the temple 2 ' , The easy opening of the temples 2 . 2 ' on the implant is also on the teeth here 8th at the temple 2 ' to recognize. It can be seen that several teeth are arranged in series one behind the other. At the temple 2 on the other hand, only the tooth height of the teeth is in each case 8th to recognize.

At the same time, the anterior-cranial stop was 5 and the anterior-caudal stop 6 shown. Also the opening with the X-ray contrast agent 10 was presented. Sideways is the breakthrough 9 to recognize.

LIST OF REFERENCE NUMBERS

1

U-shaped intervertebral implant

2

hanger

3

support surface

4

spring element

5

Anterior-cranial stop

6

Anterior-caudal stop

7

slot

8th

tooth

9

breakthrough

10

X-ray contrast media

11

Dorsal completion

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

• DE 4416605 C1 [0005]

Claims (12)

Intervertebral implant with support surfaces that can be placed on adjacent vertebral bodies ( 3 ) and cuboid basic shape with structures on the contact surfaces to the vertebral bodies, characterized in that the implant has a bow-shaped cross-section in the Sagittalschnittebene with bracket ( 2 . 2 ' ) has a slot ( 7 ) and a trained spring element ( 4 ) and anterior-cranial and anterior-caudal attacks ( 5 . 6 ) against displacement. Intervertebral implant according to claim 1, characterized in that the slot ( 7 ) between the anterior-cranial and anterior-caudal strap ( 2 . 2 ' ) runs from ventral to dorsal Intervertebral implant according to claims 1 and 2, characterized in that the shape of the slot ( 7 ) is straight, curved, stepped or wavy. Intervertebral implant according to claim 1, characterized in that in the bracket ( 2 ) the spring element ( 4 ) at the slot ( 7 ) is arranged. Intervertebral implant according to claim 1, characterized in that the support surface ( 3 ) on the bracket ( 2 ) outward caudal and / or cranial ribs or teeth ( 8th ) or has at least one tip and / or fin. Intervertebral implant according to claim 1, characterized in that the spring element ( 4 ) has the shape of a leaf spring. Intervertebral implant according to claims 1 and 6, characterized in that the spring element ( 4 ) has a textured surface. Intervertebral implant according to claim 1, characterized in that in the bracket ( 2 ) the breakthrough ( 9 ) is arranged from lateral to lateral. Intervertebral implant according to claims 1 and 8, characterized in that the shape of the opening ( 9 ) is bent, kinked or stepped in cross-section of the sagittal plane. Intervertebral implant according to claim 1, characterized in that the spring element ( 4 ) in the bracket ( 2 ) between slit ( 7 ) and breakthrough ( 9 ) is arranged. Intervertebral implant according to claim 1, characterized in that X-ray contrast medium ( 10 ) are arranged. Intervertebral implant according to claim 1, characterized in that the implant consists of a material such as plastic with good biocompatibility, in particular PEEK.

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