WO2006099969A2

WO2006099969A2 - Method and device for the production of spinal implants

Info

Publication number: WO2006099969A2
Application number: PCT/EP2006/002317
Authority: WO
Inventors: Thomas Hoell; Gerald Fehling
Original assignee: Fehling Ag
Priority date: 2005-03-24
Filing date: 2006-03-14
Publication date: 2006-09-28
Also published as: DE102005054479A1; WO2006099969A3; DE202005021705U1

Abstract

The invention relates to a method for the production of spinal implants comprising the steps: introduction of bone cement or a similar material (17) in a liquid or pasty state into a cavity mould (10, 10', 20), matching the cavity mould (10, 10', 20) to the individual anatomical proportions, hardening the material (17) in the cavity mould (10, 10', 20) to form the implant and removal of the hardened implant for the operative implantation. The invention further relates to a device for the production of spinal implants comprising a mould (10, 10', 20) of one or more parts the interaction of which permits the shaping of the three-dimensional implant. In a first embodiment the first part or the several parts (10a, 10b) have a rigid form and form a housing within which a cavity for moulding the implant is formed. In a second embodiment the mould comprises an elastic shell in which an implant can be moulded.

Description

Method and device for producing spinal implants

The invention relates to a method and an apparatus for producing spinal implants.

Spine implants are known which can be shaped with the aid of preformed tools from a liquid or pasty material such as bone cement or another plastic. As a liquid plastic, for example, acrylate bone cement, which is sold for example under the trade name Pallacos be used.

These implants are essentially an approximately 1.5 cm large disc, which is also annular, and which are introduced, for example, instead of an intervertebral disc in the spine. Such implants are also referred to as cages.

So far, comparable implants are manufactured industrially and kept in various sizes for the operation. The surgeon selects the most suitable implant and implants it. The disadvantage here is that, as a rule, the implants are not exactly adapted to the individual circumstances of the corresponding patient.

Alternatively, the pasty material can be introduced directly into the intervertebral space, where it is shaped and cured in accordance with the respective operative individual circumstances. However, this technique using plastic cements to make implants, in particular implants to replace the cervical discs, has the disadvantage that the plastic cures in the body of the patient. On the one hand, this results in non-setting monomers of most plastic adhesives remaining in the body where can trigger logical reactions. This is especially known for polyacrylate cements whose monomers are potentially toxic. Furthermore, many of the plastic cements produce temperatures in the region of 70 ° C. during curing, which can lead to necrosis of the immediately adjacent tissue. This can result in the implant sinking or becoming loose in the bone due to the disrupted cellular structure in the neighborhood. Depending on the chemical composition of the spine, there is also a danger to the spinal cord in the area of the vertebral bone, depending on its chemical composition, which must be laboriously prevented by constant cooling.

Furthermore, freely shaped bone cement implants have the disadvantage that they are individually formed, but that they do not necessarily achieve optimal stability, because unwanted formations are difficult to control, for example, in a narrow situs or dorsal of the implant. Another disadvantage is the undesired penetration of the plastic material in the soft state in the adjacent bones.

Another disadvantage of the free-formed implants is that they have no central cavity within which a bony fusion can take place. The fusion thus arises only outside of the implant, which is why the external loads may interfere with a possibly lower bone mass.

Finally, the implantation of bone cement in addition to the use of other foreign materials, such as in particular usually on the spine in addition. B. collagen sponge necessary to protect Dura mater and spinal cord from contact with the liquid or pasty plastic. This causes costs and increases foreign material input. The general advantage of plastic cements compared to industrially prefabricated cages, however, is that the adjustment can be made intraoperatively individually and that plastic elements are considerably less expensive than prefabricated implants. This is one of the reasons why the use of plastic cements, for example on the cervical spine, still accounts for the majority of cervical spine implants in Germany.

Therefore, the object of the invention is to provide an apparatus and a method for producing spinal implants, in which the implants can be adapted individually to the respective circumstances, but the dangers of damage to surrounding tissue and adjacent vertebral bodies are avoided.

The object is achieved by a method for producing spinal implants having the features of patent claim 1 and a device for producing spinal implants having the features of patent claim 2.

Advantageous embodiments and further developments of the invention düng are specified in the dependent claims.

The inventive method for producing spinal implants has the following steps. First of all, bone cement or a similar material in a liquid or pasty state is introduced into a mold.

This mold is then adjusted during surgery to the individual anatomical conditions. Finally, the bone cement is cured, whereby the implant is formed. The finished implant can then be removed from the mold and surgically implanted. The inventive method thus provides, during the operation individually for the patient with the help of suitable tools to produce implants, which are implanted after curing of the material. 5

The advantage of the inventive technique over the introduction of the liquid or pasty material directly m the Zwischenwirbelräum is that the risks due to the rather random shaping, the release of

10 heat energy and the release of chemical substances to the surrounding tissue are bypassed. There are adapted to the patient needs adapted but nevertheless made with high precision implants. Direct contact between the reacting material components and the patient is avoided.

15 the. This is a high security against unwanted

Deformation, cavitation, chemical and thermal reactions when handling plastic cements ensured. Furthermore, this method allows a precise and reproducible compared to the hand-molding of implants

20 and thus the safety increasing production of individual implants.

The inventive device for producing spinal implants is designed as a form consisting of one or ^~> .5 several parts, which allow their interaction, the impression of three-dimensional implant.

Essentially, two different types of molds 30 are used. Both forms serve to cure the pasty or liquid material outside the patient's body to avoid the patient's thermal and chemical stresses, but to be able to adapt the shapes to the patient during surgery. In a first alternative, the one or more parts are rigidly formed, which form a housing, in the interior of which a cavity for molding the implant is formed.

During surgery, as soon as the damaged intervertebral disc is removed and the size of the intervertebral space becomes apparent, the shape suitable for these operative conditions can be selected individually for the respective patient and the corresponding implant can be manufactured and adapted on site. The curing of the implant material takes place outside of the body, whereby the thermal and chemical stress of the patient can be prevented.

Preferably, an injection opening is arranged in the mold. Thus, the hollow mold can be filled from the outside with the liquid or pasty material even after assembly from its individual parts.

Advantageously, the individual parts of the mold are connected by a mechanical connection, preferably by joints and / or self-retaining closures. This ensures that the individual parts of the mold can each be assembled in a fixed position relative to each other. In addition, after filling the mold with the liquid or pasty material and after curing of the material, the mold can be easily opened again to remove the implant can.

In an advantageous embodiment of the invention, the mechanical connections hold the individual parts of the mold in a form-fitting manner. This ensures that when filling the mold, the material can not penetrate through bad contacts between the individual parts.

In a particularly preferred embodiment of the invention, the mold consists of two parts, preferably one Bottom part and a lid part. A mold of two parts is particularly easy to assemble and open. For this purpose, preferably, the two parts are connected via a mechanical connection in the manner of a hinge.

In an advantageous embodiment of the invention, an elastic insert consisting of one or more parts is arranged in the housing in order to be able to form negative angles of molding in the implant, but nevertheless to be able to detach the implant from the mold after the material has hardened out.

Preferably beads or lips are arranged in the region of the contact zones of the individual parts of the elastic insert, which engage in one another when assembling the individual parts and serve to avoid burrs on the outside of the implant.

Advantageously, the mold has an opening for receiving an insertion tool, which is preferably arranged in the region of the contact zone between the bottom and top part of the tool. The insertion tool serves to be able to grip and implant the implant without having to touch it with other instruments, whereby it could possibly be damaged.

Advantageously, the insertion tool is designed in the manner of a screw or a threaded rod. This embodiment of the insertion tool ensures that the insertion tool can be removed from the cured implant after removal of the implant from the mold and insertion into the intervertebral space without damaging the implant.

Preferably, the mold is provided with movable pins and / or carriages for forming holes and recesses, in particular for inserting the insertion tools, into the impactor. lantate equipped, which can be pulled out or rotated after curing of the material.

In a particularly preferred embodiment of the invention, the mold allows the molding of several implants simultaneously. This has the advantage that at the same time implants in different sizes and shapes can be made.

In a preferred embodiment of the invention, the height of the mold is variable, preferably by an interposed element, preferably an element in the form of a metal plate. This ensures that the form can be adapted during the surgical procedure in accordance with the individual circumstances of the patient in order to be able to produce implants of different heights.

A particularly advantageous embodiment of the invention is that the inside of the mold has a surface coating. This ensures that the cured material does not stick to the tool.

In an advantageous embodiment of the invention, the cavity formed in the mold has at least one passage area. Within such a region of development, a bony fusion can take place, which ensures increased stability.

Preferably, the mold has a connection for evacuating the mold. An evacuation of the mold before filling the liquid or pasty material ensures that the material is distributed throughout the mold and no air bubbles occur.

Advantageously, a sleeve insert is arranged in the injection opening. Through the sleeve insert, the material is injected into the mold, wherein the sleeve with factory fabric is filled. After hardening, the sleeve insert is turned off and the spray nose is removed from the implant so that a smooth outer surface of the implant is ensured. At the same time, the tool is freed of superfluous sprayed material.

Preferably, the mold has valved openings which preferably open as soon as a certain level of overpressure within the mold is reached. These allow a discharge of the excess material.

In a second alternative, the mold is formed from an elastic sheath. In this, the liquid or pasty material is filled, in which case the filled elastic sheath used in the intervertebral space and the vertebrae are relaxed as far as the subsequent relative position of the vertebrae corresponds to each other, so that the shell exactly to the individual circumstances of appropriate patient is adjusted. In particular, the use of an elastic sheath also allows the production of negative angles or undercuts. However, the sheath is only left in the intervertebral space until the material has cured to the extent that no changes in shape take place. The elastic sheath is then removed from the disc space so that most of the curing process again takes place outside the body to prevent thermal and chemical stress on the patient. Subsequently, the elastic sheath can be torn off the cured implant and the implant can be implanted.

Preferably, the elastic sheath is made of polyethylene or silicone. This allows a particularly easy detachment of the implant from the tool. Preferably, the elastic shell has an injection opening, so that the shell are filled with the liquid or pasty material.

Advantageously, the elastic shell has an opening for an insertion tool, wherein the insertion tool is preferably designed in the manner of a screw or a threaded rod. The insertion tool serves to be able to grip and implant the implant without having to touch it with other instruments, which could possibly be damaged. This configuration of the insertion tool as a screw or threaded rod ensures that the insertion tool can be removed from the cured implant after removal of the implant from the mold and insertion into the intervertebral space without damaging the implant.

In an advantageous embodiment of the invention, the inside of the elastic shell on a Oberflächenbe- layering to remove the elastic shell after curing of the material residue.

The elastic sheath preferably has at least one plowing area in order to be able to ensure a bony fusion of the adjacent vertebral bodies.

Advantageously, the elastic sheath is substantially annular, U-shaped or H-shaped, whereby different structural areas, either central or lateral, form.

Preferably, the elastic sheath on a port for evacuation in order to evacuate the envelope before filling with the liquid or pasty material to prevent air pockets. In a particularly preferred embodiment of the invention, the elastic sheath on stabilizing elements. These prevent the short-term onset of filled with liquid or pasty material shell in the Zwischenwirbelräum and relaxing the adjacent vertebrae an undesirable deformation of the shell and ensure certain minimum dimensions of the implant to be produced. For this purpose, the elastic sheath preferably has at least one stabilizing element extending from anterior to posterior.

Advantageously, the stabilizing elements are arranged in tabs in order to prevent contact of the stabilizing elements with the liquid or pasty material and thus a "ingrowth" of the stabilizing elements into the implant and furthermore to ensure a substantially smooth outside of the implant.

In a preferred embodiment of the invention, the elastic sheath on its cranial and / or caudal side formed by substantially rigid material areas in which structuring are formed. These structures serve to fix the implant in the adjacent vertebrae and prevent slippage of the implant to λ 1. For this purpose, the structures are preferably formed in the manner of cones, pyramids, teeth, teeth, keels, fins or nubs.

Preferably, the elastic sheath has channels for receiving metallic elements which serve to create channels or notches in the implant in which insertion instruments can be secured.

In a particularly preferred embodiment of the invention düng, the elastic sheath valve-like openings, which open as soon as a certain level of overpressure is reached within the elastic sheath. This is Ensures that excess liquid or pasty material can escape.

Preferably, the interior of the elastic sheath is connected via the valve-like openings with reservoirs for receiving the excess bone cement or similar material to specifically collect the material and in particular during the phase of insertion of filled with liquid or pasty material elastic sheath in the Zwischenwirbelräum To prevent leakage of the material into the intervertebral space and adjacent tissues. For this purpose, the reservoirs are preferably arranged on the outside of the elastic sheath or in one of the through-connection regions.

In a preferred embodiment of the invention, the reservoir disposed in one of the passage regions is formed by an outer shell, a metallic two-part shell disposed in the outer shell, and an inner shell disposed in the metallic shell, the inner shell being over the valved openings is connected to the elastic sheath. This makes it possible to catch the escaping material and to remove the reservoir even within the thru-hole area.

In order to be able to remove the elastic sheath after the material has hardened, the elastic sheath can advantageously be torn open along at least one predetermined breaking line. For this purpose, the at least one predetermined breaking line is preferably formed by a weakening of the material, a perforation or a material reinforcement, in order to allow a targeted tearing of the elastic sheath.

In a preferred embodiment of the invention, the at least one predetermined breaking line is formed extending from anterior to posterior. Preferably, the elastic sheath is double-layered. On the one hand, this provides additional security when inserting the elastic sheath filled with the liquid or pasty material into the intervertebral space, but also allows the sheath to be torn open and torn off the cured implant even in the state inserted into the intervertebral space.

In a particularly preferred embodiment of the invention, the elastic sheath is formed of at least two tearing tabs connected by predetermined rupture lines extending from the anterior side to the posterior side, leading from the anterior side to the posterior side and returning to the anterior side after attachment to the posterior side are. This allows a tearing and tearing of the elastic sheath of the cured material even in the case that the filled with the liquid or pasty material shell was inserted into the disc space and after relaxation of the vertebra could not be removed.

In an advantageous embodiment of the invention, the elastic sheath on at least one extending in the vertical direction shock absorber in order to ensure the relaxation of the vertebrae a certain minimum height of the implant to be produced. For this purpose, the shock absorber is preferably formed by a plunger which is axially movable in a tubular sleeve, wherein the movement of the plunger in the sleeve is damped by friction and / or by a spring element arranged in the sleeve.

The invention will be explained in detail with reference to the embodiments illustrated in the following figures. It says:

FIG. 1a is a top view of an exemplary embodiment of a device for producing spinal column Implants consisting of two parts in unfolded state,

FIG. 1b shows a side view of the embodiment according to FIG. 1 in the folded state, FIG.

FIG. 1 c shows a top view of a further exemplary embodiment of an apparatus for the simultaneous production of a plurality of spinal implants consisting of two parts in the unfolded state,

2a is a perspective view of an embodiment of a device for producing spinal implants with an elastic sheath and a Durchbauungsbereich,

FIG. 2b shows a perspective view of a further exemplary embodiment of a device for producing spinal implants with an elastic sheath and two structural areas,

FIG. 2c shows a perspective view of a further embodiment of a device for producing spinal implants with an elastic sheath and two structural areas,

FIG. 2d shows a perspective view of a further embodiment of a device for producing spinal implants with an elastic sheath and a plurality of thru-hole areas,

2e is a perspective view of another embodiment of an apparatus for producing spinal implants with an elastic sheath, which is U-shaped, FIG. 2f shows a perspective view of a further embodiment of a device for producing spinal implants with an elastic sheath, which is H-shaped,

FIG. 3 a shows a plan view of the anterior side of a further exemplary embodiment,

FIG. 3b shows a plan view of the anterior side of a further exemplary embodiment,

FIG. 3c shows a side view of the exemplary embodiment according to FIG. 3c,

FIG. 4 a shows a sectional representation through an exemplary embodiment with stabilizing elements,

FIG. 4b shows a sectional view through a further exemplary embodiment with stabilizing elements,

FIG. 4c shows a side view of a further exemplary embodiment with stabilizing elements,

5a is a sectional view of an embodiment with valve-like openings,

5b is a sectional view of another embodiment with valve-like openings,

FIG. 6 a shows a side view of an exemplary embodiment with a plurality of predetermined breaking lines,

FIG. 6b shows a plan view of the posterior side of the exemplary embodiment according to FIG. 6a, 6c is a plan view of the anterior side of another embodiment with several predetermined breaking lines and tear tabs,

7 is a sectional view of an embodiment with a screw as an Einsetsinstru- ment,

8 is a sectional view of an embodiment with shock absorbers,

FIG. 9a. a perspective view of an embodiment with structures of the cranial and caudal side,

Figure 9b is a side view of another embodiment with structures of the cranial and caudal side and

9c shows a side view of a further exemplary embodiment with structures of the cranial and caudal side.

1 shows a plan view of an exemplary embodiment of a mold 10 for producing spinal implants with a cover part 10a and a bottom part 10b, which are connected to one another via a mechanical connection in the manner of a hinge 13. The cover part 10a and the bottom part 10b are formed as substantially square plates, which consist for example of metal or hard plastic, and in the mutually facing side surface in each case an approximately annular recess 11 is recessed. If the cover part 10a is folded onto the bottom part 10b (compare FIG. 1b), the cover part 10a and the bottom part 10b form a housing around a cavity, which is formed by the two recesses 11 coming to rest on one another. In the cover part 10a is a one Spπtzoffnung 12 is arranged, which leads from the outside of the cover part 10a to the annular recess 11, so that even in the folded state from the outside, a liquid or pasty material 17 can be filled into the mold 10. In principle, the two annular recesses 11 can first be filled with the material 17, which should be impasto, by painting or impressing, before the cover part 10a and the bottom part 10b are folded together. However, there is the risk of air entrapment at the contact point. Therefore, the mold 10 is preferably first closed, the bottom part 10b and the lid part 10a abutting one another in a form-locking manner and being held in this position by either manual pressure or a closure, not shown, in this position. Subsequently, by the

Einspritzoffnung 12 of the material 17 in the cavity in the mold 10, for example by means of a syringe, injected. After curing of the material 17, the mold 10 is opened again and the implant formed from the cured material 17 can be removed. The

Form 10 thus allows the molding of a three-dimensional substantially annular implant.

In the Emspritzoffnung 12 a Hulseneinsatz 15 is set sets by which the material can be injected 17 m the mold. In this case, the Hulseneinsatz 15 is filled with the material 17. After curing, the sleeve insert 17 is turned off and thus the spray nose is removed from the implant resulting from the hardened material 17, so that a smooth outer side of the implant is ensured.

The inner surface of the annular recesses 11 may be provided in an embodiment, not shown, with an elastic insert which also permits the formation of negative angles of molding on the implant. In the area of the contact zones between the two annular recesses 11 In another embodiment, the form of beads or lips are arranged on the elastic inserts, which engage in one another when the form 10 is folded and prevent the formation of a ridge along the outside of the implant.

In another embodiment, the inner surface of the annular recesses 11 or the inner surface of the elastic inserts is provided with a surface coating, which consists for example of a ceramic, Teflon or ¹ silicone coating, so that the implant in any case looks good let the tool dissolve out.

In a further embodiment of the mold 10, not shown, in addition to the injection opening 12, a further opening in the mold 10 is arranged in the region between the bottom part 10b and the cover part 10a, which serves to receive an insertion tool. In order to be able to remove the implant from the mold 10 after hardening of the material 17 without damaging it, an inserting operation is introduced through the further opening into the cavity in the mold 10, the end of which is subsequently injected by the injection opening 12 17 is flown around. After curing, the Einsetzwerkseug is thus firmly connected to the implant, so that after opening the mold 10, the implant can be removed on the insertion tool. To be able to remove the insertion tool from the implant after implantation of the implant in the intervertebral space, the insertion tool is designed in the manner of a screw or a threaded rod, which can then be rotated out of the implant without damaging the implant.

In an alternative embodiment not shown, the mold 10 is provided with movable pins and / or slides, which from the outside of the housing

Form 10 can be inserted into the cavity to form holes and / or recesses in the implant can. After curing of the material 17 and opening of the mold 10, the implant can also be grasped and removed from the mold 10 with a corresponding instrument at these holes, notches or recesses.

In order to vary the height of the mold 10, so that it is also possible to produce the appropriate implant during the operation, depending on the operating conditions and individual dimensions of the respective patient, an element can be placed between the lid part 10a and the bottom part 10b as a spacer between For example, in the form of a metal plate, which also has an annular recess which has the same dimensions as the annular recesses 11. By varying the thickness of the metal plate, the height of the resulting implant can thus be varied and adjusted individually for the respective patient.

Characterized in that the recesses 11 are formed annularly in the mold 10, which formed in the form 10 through the two annular recesses 11 cavity a Durchbauungsbereich 14. The cut-through region 14 allows a bony fusion, in particular of the cervical, thoracic and lumbar spine, and thus ensures increased stability.

Through the injection port 12 or an additional, not shown further opening the mold 10 can be evacuated before it is filled with the material 17 to avoid trapped air and to ensure that the mold 10 is completely filled with the material 17. In order to allow excess material 17 to escape from the cavity, the mold 10 has valve-like openings. These can be formed either by one or more outlet openings, which are arranged, for example, at the point of the cavity furthest away from the injection opening 12, so that as soon as the material 17 has spread out from the injection opening 12 in the entire cavity and filled it completely, the material 17 exits at the opposite outlet opening. The outlet openings can, in order to ensure an even better filling of the cavity, additionally be designed such that they do not open until a certain level of overpressure inside the cavity has been reached.

FIG. 1c shows a further embodiment of a mold 10 ', which allows the simultaneous molding of several implants. Like reference numerals designate like parts as in FIGS. 1a and 1b. The mold 10 'shown in FIG. 1c differs from the previously described mold 10 only in that substantially two molds 10 according to the embodiments described above are joined together in order to simultaneously mold two implants, in particular two implants of different sizes allow to provide a suitable selection of implants for each patient. After trying out a first implant in situs can then be switched to a larger or smaller implant, without this being associated with additional costs or efforts. This approach is also useful because the offered on the market packaging sizes of plastic cements are usually much larger than the necessary amounts for a single implant, the excess remainder usually has to be thrown away unused, since it also cures, but is not shaped accordingly.

The mold 10 according to one of the described embodiments can now be used as follows in a method for producing a spinal implant. First, the material 17, a bone cement or a similar material in the liquid or pasty state is introduced into the cavity in the mold 10. At this time, the patient had the damaged disc already removed so that the surgeon knows the dimensions of the resulting intervertebral space. Therefore, before filling the material 17, the cavity of the mold 10 can be adapted to the individual anatomical conditions, in particular by selecting the height of the implant to be produced and by simultaneous molding of several implants with different diameters. Subsequently, the material 17 is cured in the mold 10 to form the implant and removed from the mold 10 for operative implantation. The mold 10 may then be cleaned and reprocessed and re-sterilized for re-engagement.

FIGS. 2 to 8 show different exemplary embodiments of a device for producing spinal implants having a shape 20 which has an elastic sheath 21. In this case, the different features of the embodiments are essentially combined with each other in any way. The same reference numerals designate the same parts.

The elastic sheath 21 may be made of a knitted or knitted fabric, or of an elastic plastic such as silicone, polyethylene or the like, and is preferably sterilizable. The use of an elastic sheath 21 allows for easier detachment of the implant from the mold, since the elastic sheath 21 can be easily torn off after curing of the material, and additionally allows negative angles in the implant design. Preferably, the inside of the elastic sheath 21 of the mold 20 has a surface coating, such as Teflon or silicone, which does not affect the elastic properties of the sheath 21, but allows a residue-free detachment of the elastic sheath 21 of the implant to be produced. Figures 2a to 2f each show a perspective view of the mold 20, the elastic sheath 21 is formed differently to allow different shapes for the implant. Figure 2a shows the mold 20, the elastic sheath 21 is formed substantially annular, in particular with a substantially square cross-section. On one side, preferably the anterior side 26a of the mold 20, an injection opening 22 and a further opening 23 are arranged. Through the injection opening 22, a liquid or pasty material is introduced into the

Form 20 filled where it hardens to form the implant to be produced. The further opening 23 can perform different functions, as will be explained with reference to the following exemplary embodiments.

In the interior of the annular elastic sheath 21 of the mold 20, a cut-through region 25 is formed, which permits a bony fusion of the vertebrae adjacent to the implant and contributes to the increased stability of the operated vertebral column.

In the exemplary embodiment shown in FIG. 2b, the elastic sheath 21 of the mold 20 additionally has a web 28 which extends through the annular outer region of the elastic sheath 21 and which can likewise be filled with the material. The web 28 runs approximately parallel to the anterior side 26a of the form 20. As a result, two penetration regions 25 likewise form parallel to the anterior side 26a of the mold 20.

The exemplary embodiment shown in FIG. 2 c differs from that shown in FIG. 2 b only in that the web 28 is arranged perpendicular to the anterior side 26 a, as a result of which two structural areas 25 run perpendicular to the anterior side 26 a. FIG. 2 d shows a further exemplary embodiment of a mold 20, which has a plurality of through-areas 25, which are essentially formed from a plurality of through openings extending from the cranial side 26 c to the caudal side 26 d.

The exemplary embodiment according to FIG. 2 e has an approximately U-shaped elastic sheath 21, wherein a cut-through region 25 likewise forms in the inner region of the U-shaped elastic sheath 21.

Figure 2f shows an embodiment of a mold 20 in which the elastic sheath is H-shaped, forming depending on the length of the legs of the H one or two Durchbauungsbereiche 25 between the legs of the H.

Due to the different design of the elastic sheath 21, the shape 20 can be adapted to the individual ideas of the surgeon or the intraoperative conditions. Thus, for example, shaping features, such as the area in which the implants are implanted, which are to be used for bone perforation, can be changed in size, depending on the choice of the shape 20. This makes sense because there are surgeons, areas of different sizes that make sense consider.

In FIGS. 3a and 3b, a plan view of the anterior side 26a of the mold 20 is shown, while FIG. 3c is a side view of the embodiment according to FIG. 3b. First, the anterior side 26 a has the injection opening 22. In addition, two further openings 23 are shown, which may have different functions.

First, through one of the openings 23, but in principle by the injection opening 22, an insertion tool in the elastic sheath are introduced, so it is either flowed directly from the filled material or is pressed into the already filled material. The insertion tool serves to be able to use the implant without damage in the intervertebral space after curing of the material. As shown in Figure 7, the insertion tool may be formed as a screw 27 or threaded rod so that it can be unscrewed after curing of the material and implanting the implant from the implant without damaging the implant. In an alternative embodiment, not shown, the elastic sheath has channels for receiving metallic elements, with which different holes, recesses or notches can be formed in the implant, on which after hardening of the material and tearing off of the elastic sheath 21 corresponding instruments for insertion of the implant can attack in the intervertebral space.

One of the further openings 23, or else the injection opening 22 itself, can be used to evacuate the elastic sheath 21, in order to ensure that no air pockets form in the material to be filled and that the elastic sheath is completely filled with the material.

In principle, each of the openings 22, 23 can be used both for injecting and for evacuating the mold 20 and for inserting an insertion tool.

The injection opening 22 and the other openings 23 may be formed as hose lugs or as Luer-lock connections.

FIGS. 4a, 4b and 4c show different embodiments of the elastic sheath 21, which has stabilizing elements 28. The stabilizing elements 28 are intended to have certain minimum dimensions of the implant, in particular ne certain minimum height. For this purpose, in the exemplary embodiments according to FIGS. 4 a and 4 b, the stabilizing elements are embedded in the lateral areas of the elastic sheath 21 forming the structural area 25 and extend from the cranial side 26 c to the caudal side 26 d. They prevent the elastic sheath 21 from being over-compressed in this direction, thus providing the implant with a certain height. In the exemplary embodiment according to FIG. 4 c, on the other hand, the stabilizing element runs from the anterior side 26 a to the posterior side 26 b in order to ensure stability when inserting the elastic sheath 21 into the intervertebral space. The stabilizing elements 28 are made of reinforced material or metal fibers, for example. So that the stabilizing elements 28 of metal do not come into contact with the liquid or pasty material and do not grow into the implant, the stabilizing elements 28 are arranged in tabs, not shown. This further ensures that the outside of the implant remains relatively flat, since the stabilizing elements 28 do not penetrate into the implant. If the stabilizing elements 28 are formed from material reinforcements, this is already given.

FIGS. 9a, 9b and 9c show different embodiments of forms 20 with elastic sheaths 21, which have regions formed on their cranial side 26c and / or caudal side 26d by substantially rigid material, in which structures 29 are formed. The structurings 29 can be designed in the manner of cones, pyramids, for example according to the embodiment in FIG. 9a, teeth, keels or fins such as, for example, according to the embodiment in FIG. 9b, points or nubs, for example according to the embodiment in FIG. 9c. The structurings 29 serve to stabilize the implant used in the intervertebral space and prevent it from slipping relative to the adjacent vertebral body. This will prevent the structuring in the vertebral bodies from becoming caught and tilted.

In order to allow excess material to escape from the elastic sheath 21 and to determine whether and when the elastic sheath 21 is completely filled with material, the elastic sheath 21 valve-like openings 30, as in the embodiments of FIG 5a and 5b shown. Preferably, these valve-like openings 30 are formed so that they only open when a certain level of overpressure within the elastic sheath 21 is reached. This prevents the premature emergence of material from the elastic sheath 21, if this is not yet sufficiently filled. It would be possible to allow the material to escape from the openings 30, to cure the material and then to tear off the material hanging on the outside of the openings 30 together with the elastic sheath 21. However, in order to avoid that the material exits into the intervertebral space when inserting the elastic sheath 21 into the intervertebral space for adapting the elastic sheath 21 to the anatomical conditions of the patient, the interior of the intervertebral space is, as shown in FIGS. 5a and 5b elastic sheath 21 connected via the valve-like openings 30 with reservoirs 31 for receiving the excess bone cement or similar material. The reservoirs 31 are also formed from the material of the elastic sheath 21 and are simultaneously removed when the elastic sheath 21 is torn off the cured material. The openings 30 can either open to the outer surface of the elastic sheath 21 as shown in Figure 5a or as shown in Figure 5b to the breakdown region 25 of the elastic sheath 21 open. In order to be able to remove the reservoir 31 arranged inside the plowing area 25 after completion of the implant, the reservoir 31 arranged in one of the pervious areas 25 is replaced by an outer pod 32, an outer pod 32. arranged metallic, two-part shell 33 and arranged in the metallic shell inner shell 34 is formed, wherein the inner shell 34 is connected via the valve-like openings 30 with the elastic sheath 21. The inner sheath 34 is a substantially closed bladder, which is connected via the valve-like openings 30 with the elastic sheath 21 such that material from the interior of the elastic sheath 21 in filling the elastic sheath 21 in the interior of the inner sheath 34 über-. can occur. The two-part metallic shell 33 is used for punching or shearing the inner shell 34 after curing of the filled material such that after curing, the two parts of the metallic shell 33 are pushed towards each other in the manner of a box with a lid, the edges of the lid and the edges the box is either in abutment, so that the valve-like openings 30 are punched, or the edges of the lid engage over the box, the valve-like openings 30 are sheared off. The outer shell 32 serves essentially to hold the two-piece metallic shell 33 and to prevent it from coming off the inner shell 34.

In order to remove the finished implant from the elastic sheath 21 after filling the elastic sheath 21 and hardening the material, the elastic sheath 21 can be torn open along at least one predetermined breaking line 35. These predetermined breaking lines 35 may be formed by a material weakening, a perforation or a material reinforcement. A material reinforcement can be formed in particular by a running in or on the inside of the elastic sheath 21 wire or plastic thread, which protrudes with its one end of the elastic sheath 21 and pulls at this end causes the elastic sheath 21 is torn open. Different embodiments of the resilient sheath 21 provided with predetermined breaking lines 35 are shown in FIGS. 6a, 6b and 6c. In the embodiment shown in Figure 6a, the elastic sheath 21 has a plurality of the anterior side 26a to the posterior side extending predetermined breaking lines 35, whereby the elastic sheath 21 is divided into a plurality of tear tabs 36 which are interconnected via the predetermined breaking lines 35 and torn off separately can be. FIG. 6b shows the plan view of the posterior side 26b of the embodiment shown in FIG. 6a.

In the embodiment illustrated in FIG. 6c, the tear-open tabs 36 formed by the predetermined breaking lines 35 extending from the anterior side 26a to the posterior side 26b, which likewise extend from the anterior side 26a to the posterior side 26b, are again attached to the posterior side 26b returned to the anterior side 26, wherein the returned tear tabs 36 are connected by the predetermined breaking lines 35. In FIG. 6c, the ends of the tear-open tabs 36 fastened to the anterior side 26a are designated 37, while the returned ends are designated by the reference numeral 38. The returned ends 38 of the tear tabs 35 are also secured to the anterior side 26a, for example via an easily releasable glue dot 39, to allow easy gripping of the recycled ends 38 to rupture the elastic wrap 21. When pulling on the returned end 38 of one of the tear tabs 36, the connection to the adjacent tear tabs 36 breaks along the predetermined breaking line 35 and the connection of the tear tab 36 to the posterior side 26b also breaks. Subsequently, the tear tab 36 can be removed without having to resort to the posterior side 26b. This configuration of the tear-open tabs 36 makes it possible for the elastic sheath 21 to be inserted into the intervertebral space from the cured material, even in the event that the sheath filled with the liquid or pasty material is inserted into the intervertebral space. was set and after relaxing the vertebra could not be removed, still up and tear down.

So that the elastic sheath 21 retains a certain minimum height when inserting the elastic sheath 21 which has not yet been cured into the intervertebral space, the elastic sheath 21 in a further exemplary embodiment shown in FIG. 8 has a shock steamer 45a, 45b running in the vertical direction , The exemplary embodiment according to FIG. 8 shows two different variants 45a, 45b of shock absorbers, with usually only one of the two variants being used in an elastic sleeve. Both impact steamers 45a, 45b have a tappet 47 which is axially movable in a tubular sleeve 46, the movement of the impact ice 47 m of the sleeve 46 being essentially friction-driven in variant 45a and substantially by a sleeve 46 in variant 45b Spring element 48 is steamed. If the filled with not yet cured material elastic sheath 21 is introduced into the disc space, wherein the adjacent vertebrae are kept pressed apart, and then relax the vertebrae, the shock absorbers 45, 45a, 45b catch the pressure and prevent the elastic sheath in the direction between the cranial side 26c and the caudal side 26d is compressed too much.

The mold 20 with the elastic sheath 21 according to one of the exemplary embodiments described above can be used as follows in a method for producing spinal implants. First, the bone cement or a similar material in the liquid or pasty state is filled into the elastic shell until it is completely filled. The patient has already been prepared so far that the damaged intervertebral disc has been removed and the corresponding intervertebral space is exposed. The with the still mouldable liquid or pasty material filled elastic sheath 21 is inserted into the intervertebral space and the adjacent vertebrae are relaxed. As a result, the elastic sheath 21 is adapted exactly to the individual anatomical conditions of the respective patient. Once the material has hardened so much that a change in shape is no longer feared, which is the case after only 1 to 2 minutes, the elastic sheath 21 is removed again from the intervertebral space to the material hard outside the patient completely hard The complete curing process takes about 15 minutes, so that the intervertebral space and the surrounding tissue are neither in contact with the corresponding liquid or pasty material nor are they burdened by the heat generated when the material hardens After the desired implant has been cured, the elastic sheath 21 is torn off and the implant is surgically implanted.

Due to the various possibilities of adapting the implant shape to the individual patient conditions and surgeon's wishes, the implants produced in this way are superior to industrially prefabricated implants.

reference numeral

10 form

10 'form

10a lid part

10b bottom part

11 recess

12 injection port

13 hinge

14 penetration area

15 sleeve insert

17 material

20 form

21 elastic shell

22 injection port

23 opening

25 clearance area

26a anterior side

26b posterior side

26c cranial side

26d caudal side

27 screw

28 stabilizing element

29 structuring

30 valve-like openings

31 reservoir

32 outer shell

33 two-piece metallic shell

34 inner shell

35 predetermined breaking line

36 tear tab

37 attached to the anterior side end of the tear flap

38 returned end of the pull tab

45a shock absorber

45b shock absorber Sleeve plunger spring element

Claims

claims

1. Method for Producing Spinal Implants S e c tio n a n c e s t i n c e the introduction of spinal implants

5 gene of bone cement or a similar material (17) in the liquid or pasty state in a mold (10, 10 ', 20), by adjusting the mold (10, 10', 20) to the individual anatomical conditions, by the curing of the material (17) in FIG. 10 of the mold (10, 10 ', 20) for forming the implant and removing the cured implant for operative implantation.

2. Device for producing spinal column

15 implants according to the method of claim 1, e e e c h e n e d d e r c h a mold (10, 10 ', 20) consisting of one or more parts that allow in their interaction the impression of the three-dimensional implant.

20

3. A device according to claim 2, wherein the one or more parts are rigid and form a housing, in the interior of which a cavity for molding the implant is formed.

4. Device according to one of claims 2 or 3, d a d u r c h e c e n e z e i n h e that in

30 of the mold (10, 10 ') an injection opening (12) is arranged.

5. Device according to one of claims 2 to 4, d a d u r c h e c e n e c e s in that e

35. the individual parts of the mold (10, 10 ') by a mechanical connection (13), preferably by joints and / or self-locking closures, are connected.

6. Device according to claim 5, characterized in that the mechanical connections (13) hold the individual parts of the mold (10, 10 ') in a form-fitting manner.

7. Device according to one of claims 2 to 6, d a d u r c h e c e n e c e s in that the mold (10, 10 ') consists of two parts (10 a, 10 b),

10, preferably a bottom part (10b) and a cover part (10a).

8. The device according to claim 7, characterized in that the two parts are connected by a mechanical connection in the manner of a hinge (13).

9. Device according to one of claims 3 to 8, d a d u r c h e c e n e z e i c h e n e that 0 in the housing an elastic insert is arranged consisting of one or more parts.

10.Vorrichtung according to claim 9, d a d u r c h e c e n e c i n e that in the region of the contact zones of the individual parts of the elastic insert of the form beads or lips are arranged.

11.Vorrichtung according to any one of claims 2 to 10, 0 d a d u r c h e c e n e c e s in that the mold (10, 10 ') has an opening for receiving an insertion tool.

12.Vorrichtung according to claim 11, 5 characterized in that the opening in the region of the contact zone between the bottom and top part of the tool is arranged.

13.Device according to claim 11 or 12, characterized in that the insertion tool is designed in the manner of a screw or a threaded rod.

14. Device according to one of claims 2 to 13, characterized in that the mold (10, 10 ') is equipped with movable pins and / or slide for forming holes and recesses in the implants.

15.Device according to one of claims 2 to 14, characterized in that the mold (10 ') allows the simultaneous molding of several implants.

16.Vorrichtung according to any one of claims 2 to 15, d a d u r c h e c e n e c e in that the height of the mold (10, 10 ') is variable, preferably by an interposed element, preferably an element in the form of a metal plate.

17. Device according to one of claims 2 to 16, d a d u c h e c e n e c e s in that the inside of the mold (10, 10 ') has a surface coating.

18.Device according to one of claims 3 to 17, characterized in that the cavity formed in the mold (10, 10 ') at least one. Durchbauungsbereich (14).

19.Vorrichtung according to any one of claims 2 to 18, characterized in that the mold (10, 10 ') has a connection for evacuating the mold.

20.Vorrichtung according to any one of claims 4 to 19, d a d u r c h e c e n e c e s in that a sleeve insert (15) is arranged in the injection opening (12).

21. Device according to one of claims 2 to 20, in that a form (10, 10 ') has valve-like openings, which preferably open as soon as a certain level of overpressure within the mold is reached.

22.Device according to claim 2, characterized in that the mold (20) is formed from an elastic sheath (21).

23.Vorrichtung according to claim 22, characterized in that the elastic sheath (21) is formed of polyethylene or silicone.

24.Vorrichtung according to claim 22 or 22, d a d u r c h e c e n e c e s in that the elastic sheath (21) has an injection opening (22, 23).

25.Vorrichtung according to any one of claims 22 to 24, d a d u r c h e c e n e c e in that the elastic sheath (21) has an opening (22, 23) for an insert tool (27).

26. The apparatus according to claim 25, characterized in that the insertion tool is designed in the manner of a screw (27) or a threaded rod.

27.Vorrichtung according to any one of claims 22 to 26, d a d u r c h e c e n e c e in that the inside of the mold (20) has a surface coating. 5

28. The device as claimed in claim 22, wherein the elastic sheath comprises at least one through-cut region. 10

29. The device as claimed in claim 22, wherein the elastic sheath is configured substantially annular, U-shaped or H-shaped. 15

30. Device according to one of claims 22 to 29, d a d u r c h e k e n e c e in that the elastic sheath (21) has a connection (22, 23) for evacuation. 20

31. Device according to one of claims 22 to 30, d a d u r c h e c e n e c e in that the elastic sheath (21) stabilizing elements (28). 75

32.An apparatus according to any one of claims 22 to 31, wherein a resilient sheath (21) has at least one stabilizing element 30 (28) extending from anterior to posterior.

33.Vorrichtung according to claim 31 or 32, characterized in that the stabilizing elements (28) are arranged in tabs 35.

34.Vorrichtung according to any one of claims 22 to 33, characterized in that the elastic sheath (21) on its cranial and / or caudal side (26c, 26d) by essentially, 5 res material formed areas, in which structuring ( 29) are formed.

35.Vorrichtung according to claim 34, characterized in that the structurings (29) are formed in the manner of cones, pyramids, teeth, serrations, keels, fins or nubs.

36.An apparatus according to one of claims 22 to 35, characterized in that the elastic sheath (21) has channels for receiving metallic elements.

20 37.Vorrichtung according to any one of claims 22 to 36, d a d u r c h e c e n e c e in that the elastic sheath (21) valve-like openings (30), which preferably open as soon as a certain level of overpressure within the elastic

^"15 sleeve (21) is reached.

38.Vorrichtung according to claim 37, characterized in that the interior of the elastic sheath (21) via the 30 valve-like openings (30) with reservoirs (31) for receiving the excess bone cement or similar material (17) is connected.

39.Vorrichtung according to claim 38, 5 characterized in that the reservoirs (31) on the outside of the elastic see envelope (21) or in one of the Durchbauungsbe- areas (25) are arranged.

40.Vorrichtung according to claim 39, characterized in that in one of the Durchbauungsbereiche (25) arranged reservoir (31) by an outer shell (32) disposed in the outer shell metallic, two-part shell (33) and one in the metallic shell (33) arranged inner sheath (34) is formed, wherein the inner sheath (34) via the valve-like openings (30) with the elastic sheath (21) is connected.

41. The device according to claim 22, wherein the elastic sheath is able to be torn open along at least one predetermined breaking line.

42.Vorrichtung according to claim 41, characterized in that the at least one predetermined breaking line (35) is formed by a material weakening, a perforation or a material reinforcement.

43.Vorrichtung according to claim 42, wherein a material reinforcement is formed by a wire or plastic thread extending in or on the inside of the elastic sheath.

44.Vorrichtung according to one of claims 41 to 43, characterized in that the at least one predetermined breaking line (35) is formed extending from anterior to posterior.

45.Vorrichtung according to any one of claims 22 to 44, d a d u r c h e c e n e c e s in that the elastic sheath (21) is formed double-layered.

46.An apparatus according to any one of claims 22 to 45, wherein a resilient sheath (21) is connected to at least two predetermined breaking lines (35) extending from the anterior side (26a) to the posterior side (26b)

Tear tabs (36) which are guided from the anterior side (26a) to the posterior side (26b) and after attachment to the posterior side (26b) are returned to the anterior side (26a).

47. The device according to one of claims 22 to 46, wherein a resilient sheathing (21) has at least one vertically extending shock absorber (45a, 45b).

48.Vorrichtung according to claim 47, characterized in that the shock absorber (45a, 45b) by a in a tubular sleeve (46) axially movable plunger (47) is formed, wherein the movement of the plunger (47) in the sleeve by friction and / or is damped by a spring element (48) arranged in the sleeve.