EP2162097A2

EP2162097A2 - Intervertebral prosthesis, and instrument combination comprising an intervertebral prosthesis

Info

Publication number: EP2162097A2
Application number: EP08758103A
Authority: EP
Inventors: Janos Borgulya
Original assignee: Individual
Current assignee: Individual
Priority date: 2007-05-23
Filing date: 2008-05-21
Publication date: 2010-03-17
Also published as: DE102007024262B4; WO2008141633A3; WO2008141633A2; DE102007024262A1

Abstract

The invention relates to an intervertebral prosthesis (1) comprising a top part (10) and a bottom part (11) which are movable relative to one another by means of a joint (3) that has a preferably substantially spherical shell (12) and a preferably substantially spherical engaging element (13). The top part and the bottom part have a substantially convex-concave shape from a top view.

Description

Intervertebral disc prosthesis and instrument cluster with a

Disc prosthesis

DESCRIPTION

Field of the invention

The invention relates to a disc prosthesis, as well as an instrument combination with a disc prosthesis.

Background of the invention

Disc prostheses are known. WO 01/01893 (inventors Thierry Marnay, Boris Beyerdorff) shows a relation to the subject invention of the same generic disc prosthesis with a top and a lower part, which are movable relative to each other via a hinge. Reference is made in its entirety to the disclosure content of this document.

Such known from the prior art disc prostheses are used anteriorly or anterolaterally. The access is almost always on the patient's abdomen, access via the back, in particular a posterolateral access with complete protection of the anterior longitudinal ligament between two vertebral bodies is usually not possible with such prostheses. A disadvantage of known disc prostheses is that the access from the abdomen is accompanied by a major operation. So runs the

Access through multiple tissue and muscle layers. At least the front longitudinal band must be removed during the operation mostly.

BESTATIGUNGSKOPIE An implantation of a disc prosthesis from the dorsal through the spinal canal is very risky and problematic.

Next, the centering of known disc prostheses is problematic. Due to the one-sided access, the surgeon often sees at most on the X-ray image whether the prosthesis is correctly centered. The center of rotation of the intervertebral disc prosthesis is still not in the physiological range.

Furthermore, in many cases it is desirable to place the center of rotation of the intervertebral disc prosthesis as far back as possible on the vertebral body. This is often insufficiently possible with known disc prostheses.

Object of the invention

The invention is based on the object to reduce the mentioned disadvantages of the prior art.

In particular, it is an object of the invention to enable the use of an intervertebral disc prosthesis via an access posterolateral, extraforaminal and trans / submuscular.

Another object of the invention is to facilitate the centering of the disc prosthesis during surgery.

It is another object of the invention to place the center of rotation of the joint as far back as possible on the vertebral body and depending on the application as possible in the physiological center of rotation. It is a further object of the invention to make it possible to dispense with at least the removal of the front and rear longitudinal band in the case of an intervertebral disk operation. As a result, an overdistraction of the segment and increased rotational instability can be avoided.

A further object of the invention is the reduction of the severity of an operative procedure which becomes necessary with an intervertebral disk operation, in particular an outpatient operation is to be made possible.

Summary of the invention

The object of the invention is already by a disc prosthesis, as well as by a

Instrument combination with a disc prosthesis solved according to one of the independent claims.

Preferred embodiments and further developments of the invention are to be taken from the respective subclaims.

Thereafter, an intervertebral disc prosthesis is provided with an upper part and a lower part. Upper part and lower part are made of a solid, non-elastic material, in particular made of titanium or surgical steel and are over a

Joint, which has a preferably substantially spherical shell and a preferably substantially spherically formed engaging element, against each other movable. The shell slides over the engagement element, whereby a joint is formed. The upper and lower part can be fixed to the vertebral bodies during surgery. So can be replaced by the prosthesis, an intervertebral disc. The engaging element, which with the shell forms a joint is preferably arranged on the lower part. The engagement element may be integrally formed together with the lower part, or be inserted as an insert (for example, metal or plastic), in particular as Kunststoffeinsätz in the lower part. An insert can allow movement in any direction for a given distance. The engagement element may also be slightly elastic, thus creating a damping.

According to the invention, the upper part and lower part in the plan view, namely the view from above of the prosthesis in the installed position, substantially convex-concave. The prosthesis thus has a substantially banana or boomerang-shaped design. Under the

Essentially convex-concave in the sense of the invention is also understood to mean a shape in which straight surface pieces merge into one another. In particular, the prosthesis may thus also comprise two substantially rectangular legs which are arranged at an angle to each other.

The inventor has found that it is possible to provide such a molded prosthesis with a joint which can be screwed posterolaterally into the intervertebral space via an access from the back. In particular, the prosthesis can be used posterolaterally, extraforaminally and submuscularly without opening the spinal canal. This considerably reduces the severity of the procedure, and even outpatient surgery is possible. Further, the removal of the front and rear longitudinal band can be avoided. In addition, a much easier centering of the prosthesis is possible via such access. Further, with such a shape, it is possible to place the joint of the prosthesis far behind the vertebral body as needed differently adapted to the respective vertebral segment.

The bilateral posterolateral, trans / submuscular approach allows complete dorsal decompression of the spinal canal to be performed endoscopically assisted.

Preferably, the spinal disc prosthesis comprises in plan view substantially two axisymmetric legs having a width which is less than 90%, preferably less than 80%, and more preferably less than 75% of the length of the entire disc prosthesis.

The legs preferably include an angle between 90 ° and 170 °, preferably between 110 ° and 150 °, and more preferably between 120 ° and 140 °.

Further, the disc prosthesis in plan view has a ratio of width to length between 1.5 and 2.5, preferably between 1.7 and 2.2. Length is understood to mean the extent of the prosthesis in the direction of the patient.

In a further development of the invention, the intervertebral disc prosthesis has at least two, preferably edge-side arranged on the legs holding elements for attachment of a holding tool. Thus, the intervertebral disc prosthesis can first be inserted posterolaterally from one side. Via a second posterolateral access on the other side of the spine, the prosthesis can move towards the Inserted simultaneously with a second tool taken and so optimally centered. Such a surgical procedure comes with two small cuts on the back of the patient.

The retaining elements are preferably as a thread or

Eyelets / surveys trained. In particular, it is provided to provide a thread for the tool for inserting the prosthesis, via which the prosthesis can be firmly connected to the insertion tool. After insertion, another eyelet / elevation or thread can be grasped quickly from the opposite side by means of another tool and then the prosthesis can be centered by movement of both tools under view without X-ray inspection.

In a development of the invention, the engagement element and / or the shell of the joint are designed to be movable horizontally in at least one direction. Thus, a movement is made possible not only around the pivot point of the joint, but also a horizontal displacement of the upper part and lower part. Thus, the functionality of the prosthesis closer to a natural disc. In a further development, the engagement element is designed to be movable in both horizontal spatial directions.

In an alternative embodiment of the invention, the engagement element is firmly connected to the upper or lower part, in particular integrally formed.

The hinge is preferably arranged substantially centrally between the two legs. In a particular embodiment of the invention, the surface of upper part and / or lower part falls off at the side edges to the outside. The edges are therefore bevelled. Thus, at the edge required removal of bone material should be reduced, which increases the useful life of the prosthesis in many cases. The bevel preferably takes on both sides at least 10% of the width of the prosthesis.

In a further development of the invention, the upper and / or lower part preferably have spikes arranged essentially at the edge on the legs for engagement in the bone of a patient. The inventor has found that peripheral spikes located at the ends of the legs facilitate centering against centrally located spikes. However, it is also provided in an alternative embodiment of the invention to dispense with the use of spikes or other bone engaging elements. In most applications, a structured surface of the top and bottom of the prosthesis is sufficient to ensure adequate support.

In a further development of the invention, the intervertebral disc prosthesis both means for producing a rigid connection to a holding or handling tool, as well as means for producing a movable connection to a holding tool. The means for producing a rigid connection may be formed, for example, as a thread or preferably conical fit, the means for producing a movable connection are formed, for example, as an eyelet / elevation, which can engage with a hook. About the holding tool with the rigid connection, the intervertebral disc prosthesis can be pushed from one side between the vertebrae. Then, the intervertebral disc prosthesis can be adjusted with the aid of the other holding tool, via which there is a movable connection.

Preferably both means for producing a rigid attachment with a holding tool, as well as means for producing a movable connection with a holding tool are provided on both sides. So it is possible the

Insert intervertebral disc prosthesis from both sides.

In a preferred embodiment of the invention, the holding element is designed for producing a rigid connection in order to cooperate with a retaining tool designed as a striking tool. Another holding element preferably cooperates with a holding tool designed as a pulling tool. By the combination of pressure on the impact tool and train on the pulling tool an exact adjustment of the prosthesis can be achieved.

The holding element as a wrapping tool can be replaced on the same side a pulling tool. It is also possible to provide an instrument which is simultaneously designed as a pulling and driving tool.

Furthermore, the invention relates to an instrument combination with an intervertebral disc prosthesis which has at least two retaining elements for engagement of a holding tool, wherein the instrument combination comprises at least a first and a second holding tool, and wherein the first and the second holding tool can be fastened to the holding elements simultaneously. Furthermore, it is provided in a development of the invention to connect the both sides attached tools firmly together and thus to form a solid, rigid construction. Thus, a positioning can be facilitated without X-ray control.

Furthermore, it is provided in a further development of the invention to attach a holding tool in the middle of the prosthesis and thereby to enable a conventional antero-posterior implantation.

Such an arrangement allows a disc prosthesis to be inserted and centered via a bilateral posterolateral approach. In this case, the prosthesis can be introduced with a holding tool via an access and taken after insertion via the second access on the opposite side and centered by means of both holding tools.

The fixed holding tools enclose an angle between 90 ° and 170 °, preferably between 110 ° and 150 ° and particularly preferably between 120 ° and 140 °. For the formation of a recess in a preferred embodiment of the invention, an arc-shaped bone rasp is used, which is adapted to the shape of the intervertebral disc prosthesis.

The invention further relates to a method for inserting an intervertebral disc prosthesis, in which a jointed intervertebral disc prosthesis is inserted via an extraforaminal, trans / submuscular, posterolateral approach. The inventor has found out that this access can provide a particularly simple and tissue-conserving method for using an artificial ligament disc. In particular, a biportal access can simultaneously ensure an exact adjustment.

Preferably, the disc prosthesis is used for tissue preservation via a trans- or sub-muscular approach.

The inventive method is suitable for use almost between all vertebrae and in an alternative embodiment of the invention in all directions, in addition to posterolateral so also anterolateral, anterolateral transmucular and anteroposterior. Thus, the prosthesis can thus be implanted antero-posterior, anterolateral and anterolateral transmuclear.

A strictly antero-lateral transmuclear approach in the preparation and implantation angle of 15 ° to 70 ° preserves the preservation of the anterior longitudinal ligament

Brief description of the drawings

The invention will be explained in more detail below with reference to a schematically illustrated embodiment.

Fig. 1 shows schematically an embodiment of an intervertebral disc prosthesis in plan view.

Fig. 2 shows an alternative insertion position of the prosthesis. Fig. 3 shows a schematic side view of an intervertebral disc prosthesis seen from the rear.

Fig. 4 shows the use of an instrument combination with a disc prosthesis.

Detailed description of the drawings

Fig. 1 shows schematically a plan view of an embodiment of a disc prosthesis 1 according to the invention, here used on a vertebral body 2. The disc prosthesis 1 is formed substantially convex-concave and comprises two legs 6, which extend axially symmetrically from the hinge 3. The intervertebral disc prosthesis 1 comprises an upper and a lower part (not shown). A joint 3 allows a movement of the upper and lower parts to each other, wherein the center of rotation 4 is substantially between the legs 6. The lower part (not shown) comprises an engagement element which is horizontally movable to the lower part. The movement of the engagement element is limited by a stop 5. The ratio of width b to length 1 of the intervertebral disc prosthesis 2 in this embodiment is about 1.5 to 2.5. The width b 'of the legs 6 is less than 75% of the length 1 of the intervertebral disc prosthesis 1. The legs 6 are rounded at the edge.

Next, the legs edge-side spikes 7, which can penetrate into the bones of the vertebral body 2 and so provide better fixation. For centering are beside Holding elements for a holding tool (not shown) recesses or bolts 8 and notches 9 are provided.

The intervertebral disc prosthesis 1 is inserted in this example via a bilateral posterolateral access. The inventor has found that in addition to the accessibility, the shape of the invention is also particularly well matched to the viable areas of the vertebral body 2.

Fig. 2 shows that already shown in Fig. 1

Intervertebral disc prosthesis 1 in a different position. Here, the intervertebral disc prosthesis 1 was inserted via an anterolateral approach and is therefore rotated by 180 ° to the vertebral body 2. Thus, the joint 3 can be arranged particularly far back against the vertebral body 2.

Fig. 3 shows a side view of an embodiment of a disc prosthesis 1 from the rear, so seen in the inserted state from the back side. The intervertebral disc prosthesis 1 comprises an upper part 10 and a

Lower part 11, which are formed in particular of coated titanium or surgical steel. The upper part 10 comprises a shell 12, which slides over an arranged on the lower part 11 engaging element 13 and thus forms a hinge.

The engagement element 13 is designed as a horizontally movable insert. The horizontal movement is limited by the stopper 5, the engagement element 13 has horizontal play between 1 and 5 mm in all directions. Upper and lower part 11 are therefore not only movable relative to one another via the joint, but can also move horizontally against one another as a result of the movement of the engagement element 13. Alternatively, the Engagement element also be firmly connected to the lower part (not shown).

Further comprise upper part 10 and lower part 11 at its two edges in each case a thread 14 and an eyelet / pin / pin 15, which holding tools (not shown) serve as a fastening point.

Upper part 10 and lower part 11 are edge-chamfered over a length of more than 10% of the width of the disc prosthesis 16. Thus, a better centering is to be made possible, at the same time the edge-side removal of bone material is at least reduced.

The engagement element 13 is formed in this embodiment with the lower part 11 horizontally movable in each direction to a limited extent. Between the four stops 5, the engagement element is centered positioned and then locked. At the slightest movement, the engagement element 13 'shifts to the side (possibly antero-posteriorly) under stop 5 and can no longer be dislocated.

Referring to Fig. 4, the insertion of a disc prosthesis 1 according to the invention will be explained. The convex-concave disc prosthesis 1 is screwed between the vertebral bodies 2 with a first holding tool 17, which can be screwed into a thread 14 of the disc prosthesis 1 or has a pin for producing a rigid connection to the disc prosthesis 1. Then, the disc prosthesis 1 is gripped on an eyelet / pin / pin 15 on the opposite side with a second holding tool 18. About pressure and train to the two holding tools 17, 18, the surgeon (not shown) center the disc prosthesis 1 exactly. The holding tools 17, 18 are designed such that they can enclose the angle α, which form the legs 6 of the intervertebral disc prosthesis 1 to one another. Both holding tools 17, 18 each include a handle 19 for handling.

In this embodiment, therefore, the left holding tool 17 enters into a rigid connection with the intervertebral disc prosthesis 1 and can be used as a striking tool for inserting the prosthesis.

The right holding tool 18 is movably connected to the disc prosthesis 1 and serves primarily as a pulling tool for the exact adjustment of the

Intervertebral disc prosthesis 1, after this was brought between the vertebral bodies (not shown). Alternatively, it is provided to provide both tools with both functionalities.

Bolts are preferably for attachment of hooks of a positioning tool (not shown) and may also be used as a ram engagement surface (not shown).

The engagement element may be fixedly connected to the lower part of the prosthesis and thus form a ball joint (not shown). This joint shape also allows implantation of a disc prosthesis in vertebral artery arthrosis even with resection of the vertebral joint on both sides of the posterolateral, trans / submuscular bilateral access. In this case, a total endoprosthesis can thus be provided. FIG. 5 shows schematically the holding tool 17 known from FIG. 4 in the side view, which is designed as a striking tool. For attachment of simultaneously upper and lower parts of the intervertebral disc prosthesis (not shown), the holding tool on two pins 20 which form with corresponding recesses of the intervertebral disc prosthesis, for example, a conical fit. After insertion of the disc prosthesis, the holding tool 17 can be easily released and pulled back.

LIST OF REFERENCE NUMBERS

1 intervertebral disc prosthesis

2 vertebral bodies

3 joint

4 turning center

5 stop

6 thighs

7 spike

8 recess or bolt

9 notch

10 shell

11 lower part

12 bowl

13 engagement element

14 threads

15 eyelet

16 bevel

17 First holding tool

18 Second holding tool

19 handle

20 pin with fit

Claims

Claims :

An intervertebral disc prosthesis comprising an upper part and a lower part, wherein the upper part and the lower part are movable relative to one another via a joint, which has a preferably substantially spherical shell and a preferably substantially spherical trained engaging element, characterized in that upper part and lower part are formed in the plan view substantially convex-concave.

2. Intervertebral disc prosthesis according to the preceding claim, characterized in that the upper part and lower part in the plan view essentially comprise two legs, which preferably extend axially symmetrically starting from the joint.

3. Intervertebral disc prosthesis according to the preceding claim, characterized in that the legs have a width which is less than 90%, preferably less than 80% and particularly preferably less than 75% of the length of the entire intervertebral disc prosthesis.

4. Intervertebral disc prosthesis according to one of the preceding

Claims, characterized in that the legs form an angle between 90 ° and 170 °, preferably between 110 ° and 150 ° and particularly preferably between 120 ° and 140 °.

5. Intervertebral disc prosthesis according to one of the preceding claims, characterized in that the intervertebral disc prosthesis in plan view a ratio from width to length between 1.5 and 2.5, preferably between 1.7 and 2.2.

6. Intervertebral disc prosthesis according to one of the preceding claims, characterized in that the

Intervertebral disc prosthesis has at least two preferably arranged at the edges of the legs holding elements for attachment of a holding tool.

7. Intervertebral disc prosthesis according to one of the preceding claims, characterized in that a fastening element is arranged approximately in the middle of the intervertebral disc prosthesis.

8. intervertebral disc prosthesis according to the preceding claim, characterized in that the holding elements are designed as a thread and / or hoes and / or eyelet.

9. Intervertebral disc prosthesis according to one of the preceding claims, characterized in that at least one holding element is provided for fastening a wrapping tool.

10.Bandscheibenprothese according to any one of the preceding claims, characterized in that at least one

Holding element is provided for fastening a pulling tool.

11.Bandscheibenprothese according to any one of the preceding claims, characterized in that the

Engagement element and / or the lower part of the prosthesis horizontally in at least one direction, preferably in both spatial directions is designed to be movable.

12.Bandscheibenprothese according to one of claims 1 to 7, characterized in that both the shell and the engagement element are fixedly connected to the upper or lower part.

13. Intervertebral disc prosthesis according to one of the preceding

Claims, characterized in that the joint is arranged substantially centrally between the two legs.

14. Intervertebral disc prosthesis according to one of the preceding claims, characterized in that the surface of the upper part and / or lower part at the side edges drops outwards.

15. Intervertebral disc prosthesis according to one of the preceding claims, characterized in that the upper and / or lower part preferably have substantially peripherally arranged on the legs spikes for engagement in the bone of a patient.

16. Intervertebral disc prosthesis according to one of the preceding claims, characterized in that the legs are rounded edge, in particular in the plan view are formed substantially circular segment.

17.Bandscheibenprothese according to any one of the preceding claims, characterized in that the

Intervertebral disc prosthesis preferably on both sides means for producing a rigid attachment with a holding tool, as well as means for producing a having movable connection with a holding tool.

18. Instrument combination with a disc prosthesis, in particular one

Intervertebral disc prosthesis according to one of the preceding claims, comprising an intervertebral disc prosthesis, which has at least two holding elements for engagement of a holding tool, at least one first and one second holding tool, wherein the first and second holding tools can be fastened to the holding elements at the same time.

19. instrument combination with a disc prosthesis according to the preceding claim, characterized in that the fixed holding tools can enclose an angle between 90 ° and 170 °, preferably between 110 ° and 150 ° and more preferably between 120 ° and 140 °.

20. Instrument combination with a disc prosthesis according to one of the preceding claims, characterized in that the first and the second holding tool are connectable to each other.

21. Instrument combination with a disc prosthesis according to one of the preceding claims, further comprising an arc-shaped bone rasp.

22. Instrument combination with a disc prosthesis according to one of the preceding claims, characterized in that a holding tool a hook includes.

23. Instrument combination with a disc prosthesis according to one of the preceding claims, characterized in that a holding tool comprises a thread.

24. Instrument combination with an intervertebral disc prosthesis according to one of the preceding claims, characterized in that the intervertebral disc prosthesis and the first holding tool are formed such that the attached first holding tool enters into a substantially rigid connection with the prosthesis.

25. Instrument combination with an intervertebral disc prosthesis according to one of the preceding claims, characterized in that the intervertebral disc prosthesis and the second holding tool are formed such that the attached second holding tool enters into a movable connection with the prosthesis.

26. Instrument combination with a disc prosthesis according to one of the preceding claims, characterized in that the holding tools each have a handling handle, wherein in the fixed state of the holding tools, the handling handles at least 5 cm, preferably at least 10 cm and more preferably at least 20 cm apart.

27. A method for inserting a disc prosthesis, preferably a disc prosthesis according to one of the preceding claims and preferably carried out with An instrument cluster according to any one of the preceding claims, characterized in that a jointed disc prosthesis is inserted via an extra-temporal access. A method for inserting a disc prosthesis according to the preceding claim, characterized in that the disc prosthesis is used via a biportal access.

28. A method for inserting a disc prosthesis, in particular according to one of the preceding claims, characterized in that the disc prosthesis is inserted via a trans- or sub-muscular access.

29. A method for inserting an intervertebral disc prosthesis, in particular according to one of the preceding claims, characterized in that a joint comprising a disc prosthesis is used via a biportal access.