DE19726754A1 - Implant for fixing parts of bones in particular at spine - Google Patents

Abstract

The implant for fixing parts of bones has indents (20) on both sides for the accommodation of two connecting bars (3) which keep the bones and the implant safely in position and prevent them from getting twisted. The implant consists mainly of two bearings (1) with indents (20) on both sides (18) to accommodate two connecting bars which are held in position by a nut (27) screwed onto a thread (19) on the upper side of the bearing (1). A ball joint (12) is movable attached to the anchoring element (4).

Description

The invention relates to an implant for relative Fi Xation of bone parts, especially for the spine lenfixation, with ver anchoring elements using a releasable ball clamp are connected to each bearing body, the on the one hand a pan-shaped receptacle for a kugeli end of an anchoring element and on the other a bearing recess for a connecting rod points, and with a clamping element on the bearing body, wel ches the connecting rod in the tensioned state Bearing recess presses and thereby it relative to the La body determines and which the connecting rod there when directly or indirectly against the spherical end of the Anchoring element tensioned and this in the pan-shaped receptacle presses and relative to the bearing body stuck

Such an implant is, for example, from the DE 43 07 576 C1 known.

It can be used to cut different bone parts to determine relative to each other, in particular can  such an implant to define neighboring us use the spine. Due to the spherical ver Binding of an anchor that can be inserted into the bone part Rungselementes with a bearing body, the bearing body per position relative to the bone part be kidneyed, so that the bearing body in neighboring Bones can be aligned so that they are permanently and firmly relative by connecting rods can be aligned with each other.

In the known device, the determination is made the ball clamp connection in that the connection rod against a nut-shaped clamping element Pressure body is pressed, which in turn the kuge the end of the anchoring element. The Ver tie rod is located directly above the ball the end of the anchoring element, so this is after inserting the connecting rod from the outside no longer accessible.

Although the known implant can be used variably, is the achievable stiffening of neighboring bearing blocks per limited because the connection of the bearing body over a single connecting rod is made. There is the Danger that the bearing body about the longitudinal axis of the Can turn connecting rod against each other.

It is an object of the invention, a generic Im train plantat so that it while maintaining a structurally simple structure is suitable, even large To absorb forces safely so that the danger is reduced  will that the relatively fixed bearings change body in position.

This task is at the beginning of an implant Written type solved according to the invention in that the bearing body on both sides of the pan-shaped One bearing recess for each connection rod is arranged. This makes it possible for La body via two connecting rods other, and this includes, for example a rotation of the bearing body about the longitudinal axis of a Connecting rod with certainty. One can on the much higher fixation stabilities pass.

It is already known per se when it comes to spine to use devices where La ver body by two connecting rods be tied, but this is the anchor body not articulated to the bearing body, so that a variable adaptation to anatomical conditions is not possible (WO 96/29016).

In a preferred embodiment of the invention provided that the distance of the bearing recesses from each other is so great that there is a free connection between them walk to the spherical end of the anchoring element remains. Such a configuration also makes it possible after inserting the connecting rods into the bearing recess the spherical end of the anchoring element reach so that the anchoring element in the kno Chen can be used, although the connecting rods  be already inserted. It is possible with that Bearing body of the individual bone parts already through Insert the connecting rods relative to each other prepare and only then the anchoring elements in the Fully insert bone parts, for example by finally screwing it in.

It is beneficial if one for both connectors common clamping element is provided, in particular this clamping element can be a nut.

It is advantageous if the bearing recess has a longitudinal groove with the longitudinal grooves preferably parallel to one another other run.

If the spherical end of the anchoring element according to a preferred embodiment slightly in the Cross section of the bearing recess protrudes, the in this bearing recess received connecting rod di right at the spherical end of the anchoring element and thereby fixes the spherical end for one Clamping connection when the clamping element is tensioned. This is because the connecting rod is in a three point support set in the bearing recess, namely once at the spherical end of the anchoring element to others on the clamping element and finally in the warehouse take.

In a preferred embodiment, that the bearing body is plate-shaped. There through it becomes possible to fixie the bearing body on the the bearing part  has the function of a conventional bone plate te.

It is advantageous if the bearing body on his the underside facing away from the bearing recesses Wearing lace. These dig into what is to be determined Bone part and lead to an additional fixie tion of the bearing body relative to this bone part.

The tips can be inserted into the bearing body for example in the form of pens, but it is also possible that the tips in one piece with the bearing body are trained.

In a preferred embodiment, that the bearing body between the bearing recesses the exterior adjoining the pan-shaped receptacle threaded sleeve on which the clamping element is screwable. You get a very compact one Unit that can be pre-assembled and that is therefore easy to handle.

It is favorable if the spherical end of the veranda kerungselementes as a receptacle for a turning tool has non-circular central opening, for example one Hexagon socket.

The anchoring element can in principle be any be trained, but it is particularly favorable if the anchoring element is a bone screw.  

This can be hollow, so that after screwing in bone material remains inside. Particularly good It is always when the bone screw breaks through Chen wall areas through which the bone mat rial after inserting the bone screw can grow.

It is also advantageous if the spherical end releasably connected to the rest of the anchoring element is. This not only enables the anchoring element to be inserted in the bones beforehand and only then to apply the spherical end, but it is also possible the spherical end at a later date to be removed again when the implant is removed should, with the remaining anchoring element in the kno Chen can remain.

In particular, the spherical end in the rest of Ver anchor element to be screwed in.

To screw in the anchoring element, it is green stig when a turning tool is provided, the characterized in that it has a spherical head points, the cross section of which is formed out of round is that he is playing in the non-circular central opening is insertable in the anchoring element, so that an lead at different angles is possible that he but when turning the tool in the central one Opening a form-fitting system on the non-circular Cross section of the central opening experienced. Example the turning tool can have a spherical head point, the hexagonal revised in cross section  is so that it fits into a hexagon socket in the spherical En de of the anchoring element is insertable. If the Longitudinal axis of the hexagon socket in relation to the longitudinal axis of the turning tool is inclined, can then still the spherical head due to the existing play in insert the central opening of the spherical end, and when turning the turning tool, the six lies down redesigned spherical head on the inner surfaces of the hexagon and allows the Anchoring element.

It is also advantageous if a tool for Insertion of the described implant is provided which is characterized in that it is an in the external thread sleeve can be inserted or screwed in Sleeve includes. By inserting the sleeve into the External threaded sleeve will allow the bearing body by using a suitable instrument to posi tion, with the bone part positio is on which the bearing body is fixed. At for example, it is possible by corresponding in the Bearing body inserted sleeves two bearing bodies in ih rem distance from each other by moving into the Bearing body inserted sleeves in a be known distractor are used, who then the at the sleeves parallel to themselves in their distance adjusted.

In a preferred embodiment, further be provided that one on the sleeve on this longitudinally displaceable and rotatable relative to this one screw sleeve is attached, the one at the bottom  positive receptacle for the clamping element and in egg an area above for a target for has a turning tool. About this screw sleeve the clamping element can be screwed onto the bearing body be, while keeping in stock body inserted sleeve, which then acts as a guide for the screw-in sleeve serves. The twist of the one screw sleeve is made by a turning tool, for example wise a wrench on the attack surface can be applied.

It is favorable if the screw-in sleeve is shorter than the insertable into the external thread sleeve, so that the latter protrudes over the screw-in sleeve. To the Then the above range can be, for example Distractor can be attached to the distance from bearings bodies change relative to each other.

It is also favorable that through the in the bearing body inserted sleeve a turning tool can be inserted can with which the anchoring element also twisted can be when the sleeve is inserted into the bearing body is set and if necessary also the screw sleeve is arranged on the bearing body. This can the final screwing in of the anchoring element with the distractor attached, and it is then also possible with the distractor and if necessary still used turning tool for the Anchoring element, the clamping element by actuation to tighten the screw-in sleeve. All operations are on this way independently and if necessary feasible at the same time.

The following description of preferred embodiment forms of the invention is used in connection with the Drawing of the detailed explanation. Show it:

Fig. 1 is a perspective view of two vertebrae body when inserting an anchoring element with bearing body when screwing in the anchoring element or when fitting a screw-in sleeve onto the inserted anchor element;

Figure 2 is a longitudinal sectional view of a screwed-in anchoring element with a bearing body and fitted insertion tools;

Fig. 3 is a view similar to Figure 1 with inserted anchoring elements with inserted connec tion rods and attached distractor.

Fig. 4 is a view similar to Figure 3 with an inserted rotary tool for the final screwing egg nes anchoring element and with a rotary tool for rotating a screw-in sleeve.

Figure 5 is a longitudinal sectional view of an anchoring element used in the bone with bearing body and clamped connecting rods.

Fig. 6 is a view similar to FIG. 5 in a modified embodiment of an anchoring element with the bearing body and

Fig. 7 is a perspective view of the Veran kerungselements of FIG. 6 in the inserted state.

The implant shown in the drawing is made after following using the example of a spinal fixation system explained, that is, a system in which the vortex of Spine to be fixed relative to each other. It ver it is clear, however, that the implant is also being fixed used on other bones and bone parts in the body that can be fixed relative to each other sen, for example after a fracture of a bone.

The implant comprises parts are substantially three, NaEM Lich a bearing body 1 and connected via a ball joint to the bearing body 1 Bone screw 2 so as two connecting rods 3 for preparing a star ren connection between two bearing bodies 1, the Festge tively to re each other to be fixed bone parts be placed.

The bone screw 2 of the embodiment shown in FIGS . 1 to 5 Darge is designed as a banjo bolt and for this purpose has a Hohlzylin the 4 with a running on the outer jacket thread degang 5 and openings 6 arranged between the adjacent threads. In a head 8 of the hollow cylinder 4 provided with an internal thread 7 , a threaded ring 9 is screwed, which in turn carries an internal thread 10 , and a connecting part 11 is screwed into this internal thread 10 , which protrudes from the threaded ring 9 with a spherical end 12 . This spherical end is cut off at the top 13 , in this area in the spherical end 12 a central, hexagonal cross-section opening 14 occurs , which continues in a threaded blind hole 15 with a smaller diameter. The opening 14 with the hexagonal cross section thus forms an internal hexagon which extends approximately to the center of the spherical end 12 .

The bearing body 1 is designed as a bone plate 16 , it has a central continuous opening 17 which shows at its lower end the shape of a pan-shaped bearing ring 18 narrowing from top to bottom, while it merges upwards into an outer sleeve 19 , which protrudes upwards from the bone plate 16 . Extend to both sides of this outer threaded sleeve 19 parallel to each other two groove-shaped La geraufnahmen 20 whose cross-section be circular arc-shaped borders and on its side facing the outer threaded sleeve 19 side into the interior of the outer threaded dehülse immerse 19th In this area, therefore, the wall of the outer threaded sleeve 19 to an opening 21 immediately above the cup-shaped La gerringes 18 is disposed.

On the outer sides of the groove-shaped bearing receptacles 20 , pins 23 are inserted into openings 22 of the bone plate 16 , which protrude downward from the bone plate 16 with a pointed end 24 , while the ends 25 protruding upward from the bone plate 16 directly conform to the contour of the groove-shaped Connect storage receptacles 20 and continue them ( Fig. 5).

The bearing body 1 and the bone screw 2 are connected to one another in an articulated manner. For this purpose, the connec tion part 11 is inserted from above through the external threaded sleeve 19 until the spherical end 12 is received in the pan-shaped bearing ring 18 . The internal thread 10 of the threaded ring 9 is then screwed onto the connecting part 11 , possibly already together with the hollow cylinder 4 .

The inserted in the bearing ring 18 in this way ku gelige end 12 of the connecting part 11 protrudes through the openings 21 slightly in the two Lagerauf took 20 ( Fig. 5).

In these camp receptacles 20 , a connec tion rod 3 is inserted, the outer diameter of which is so measured that the connecting rod 3 on the one hand enters the bearing receptacle 20 entering ball end 12 and on the other hand applies to the bearing receptacle 20 itself.

On the external thread 26 of the external thread sleeve 19 , a clamping element in the form of a nut 27 is screwed, which engages with its underside on the top of the connecting rods 3 inserted into the bearing seat 20 and when tightening the connecting rods 3 both against the spherical end 12 of the connec tion part 11 as well as against the side wall of La geraufnahme 20 presses. This leads to the fact that the connecting rods 3 are fixed immovably relative to the bearing body 1 , but at the same time the ku gelige end 12 is clamped immovably in the bearing ring 18 .

In the external threaded sleeve 19 , an elongated sleeve 29 can be inserted in a form-fitting manner, which thus practically forms an extension of the external threaded sleeve 19 . A screw-in sleeve 30 is slipped onto this sleeve 29 , which overall is shorter than the sleeve 29 and which is guided on the screw-in sleeve 30 in a longitudinally displaceable and freely rotatable manner. The screw-in sleeve 30 has at its lower end a receptacle 31 for the nut 27 , which is received in a form-fitting manner in the receptacle 31 , and on the upper side a nut-shaped engagement surface 32 for a wrench 33 ( FIG. 4).

The sleeve 29 protrudes with its section 34 facing away from the bearing body 1 from the screw-in sleeve 30 , and this section 34 serves as an engagement surface for a distractor 35 of a type known per se ( FIG. 3), which essentially comprises two parts 36 , 37 which can be moved relative to one another has, each of which can be plugged onto a section 34 of a sleeve 29 of a bearing body 1 and which can be displaced in parallel with one another by a suitable drive, for example egg NEN spindle drive 38 , so that the two sleeves 29 on which the distractor 35 is placed, be changed in their distance ver.

The tool for inserting the implant further includes a turning tool 39 with a shaft 40 with a handle 41 at one end and a spherical head 42 at the other end, which has been revised so that it has a hexagonal cross section. The dimensions are chosen so that the ball head 42 can enter the hexagon-shaped area of the opening 14 with play, this also allows the ball head 42 to occur when the shaft 40 is inclined relative to the bone screw 2 . Nevertheless, a positive connection can be made when turning the turning tool 39 with respect to the bone screw 2 .

To insert the described implant, a receiving channel for the bone screw 2 is first worked into the bone in a manner known per se. In this bone channel, the bone screw 2 is screwed together with a bearing body with which it is captively connected. This screwing in can be done with the turning tool 39 or, if necessary, also with a normal polygonal wrench, which is used in the direction of the bone screw. This is a screwing process is not completely done son only to the extent that the tip end 24 of the pins 23 is not yet immersed in the bone 43 . The same procedure is followed on a second bone that is to be rigidly connected to the first bone.

After this partial screwing in of the bone screw ben 2 , the sleeve 29 and the screw-in sleeve 30 are placed on the bearing body 1 in the manner described. Just for the sake of completeness, it should be pointed out that, of course, this attachment can also take place at the beginning of the screwing-in process, then a screwing tool with a shaft that extends through the sleeve 29 must be used to screw in the bone screw 2 , as shown in FIG Fig. 1 is shown on the rear vertebral body. In the example shown there, only the sleeve 29 is attached for screwing in, the screw-in sleeve 30 is only attached after the partial screwing on (front vertebra in FIG. 1).

When a set in the vertebral body to be joined together in this manner, the bone screws 2 with bearing bodies 1, two connecting rods 3 are inserted into the bearing receptacles 20 then, as will be clear from the illustration of Fig. 3. These can be temporarily secured by means of the nut 27 , the nut 27 , which is located in the receptacle 31 and is set up with the fitting of the screw-in sleeve 30 , but is only screwed on loosely and not yet tensioned, so that a pivoting of the Bearing body 1 relative to the bone screw 2 is possible, in addition, the connecting rods 3 are still displaceable.

On the above the screw-in sleeve 30 from sections 34 of the sleeves 29 , the di stractor 35 is then placed and adjusted so that the sleeve 29 and thus the bearing body 1 and they hold the bone at the correct distance from one another.

As soon as this has been achieved, the bone screws 2 are completely screwed into the bone 43 , using the turning tool 39 , which is inserted through the sleeve 29 and dips into the opening 14 with its spherical head 42 . As described, an effective rotary connection is also possible if the longitudinal axis of the shaft 42 and the longitudinal axis of the bone screw form an angle with one another.

It is advantageous to screw in the bone screws 2 of both bones approximately evenly, if necessary by alternately attaching the turning tool 39 .

As soon as the bone plates 16 are completely screwed in, they are securely fixed to the bone 43 , since the pointed ends 24 of the tips 23 burrow into the bone material ( FIG. 5).

A final fixation of the implant takes place by turning the screw-in sleeve 30 by means of the wrench 33 ( FIG. 4), whereby both the connecting rods 3 in the bearing body 1 and the spherical end 12 in the bearing ring 18 are clamped.

When this is achieved at two bearing bodies, the distractor 35, the sleeves 29 are connected to the Einschraubhül sen 30 and peeled off the rotary tool 39, and it ver remains only the implant in the body, which via two parallel connecting rods 3, the adjacent bone density of 43 permanently and connects securely with each other.

After the healing process is complete, most of the implant can be removed. It is sufficient to open the nut 27 and remove the connecting rods 3 , then the connecting part 11 can be screwed out of the bone screw 2 in the manner described, so that the removal of the connecting part and, using a suitable tool, the removal of the bearing body 1 is possible. The bone screw 2 remaining in the bone can be closed by a suitable stopper.

The embodiment of FIGS. 6 and 7 largely corresponds to that of FIGS . I to 5, corresponding parts therefore have the same reference numerals.

In contrast to the embodiment of FIGS. 1 and 5 are missing in the embodiment of FIGS. 6 and 7 used in the bone plate 16 pins 23, but instead are connected to the bone plate 16 by protruding below pointed projections 44 formed integrally.

Another difference is the fact that not a threaded blind hole 15 connects to the central hexagonal opening 14 in cross section, but a conical blind hole 45th In this case, the turning tool 39 , with which the bone screw 2 can be screwed into the bone 43 , plunges into the hexagonal opening 14 by means of a hexagonal section 46 and into the conical blind hole 45 with a conical section 47 that adjoins the hexagonal section 46 . With this turning tool, the banjo bolt can be screwed in both directions.

Another difference from the game Ausführungsbei of FIGS. 1 to 5 can be seen in the fact that the external thread sleeve 19 additionally has an internal thread 48 , into which the elongated sleeve 29 can be screwed by means of an external thread 49 .

Otherwise, the implant according to FIGS. 6 and 7 can be used in the same way as the implant according to FIGS. 1 to 5.

Claims (22)

1. Implant for the relative fixation of bone parts, in particular for spine fixation, with anchoring elements that can be used in each bone part and that are connected via a releasable ball clamp connection to a bearing body, on the one hand a pan-shaped receptacle for a spherical end of an anchoring element and on the other hand has a bearing recess for a connec tion rod, and with a clamping element on the bearing body, which presses the connecting rod into the bearing recess in the tensioned state and thereby fixes it relative to the bearing body and which clamps the connecting rod directly or in directly against the spherical end of the anchoring element and this thereby presses into the pan-shaped receptacle and clamps relative to the bearing body, characterized in that in the bearing body ( 1 ) on both sides of the pan-shaped receptacle ( 18 ) a bearing recess ( 20 ) for a connecting rod ( 3 ) is arranged et is. 2. Implant according to claim 1, characterized in that the distance between the bearing recesses ( 20 ) vonein other is so large that between them free access to the spherical end ( 12 ) of the Veran kerungselementes ( 2 ) remains. 3. Implant according to claim 1 or 2, characterized in that a common clamping element ( 27 ) is provided for both connecting rods ( 3 ). 4. Implant according to one of the preceding claims, characterized in that the clamping element ( 27 ) is a nut. 5. Implant according to one of the preceding claims, characterized in that the bearing recess ( 20 ) is a longitudinal groove. 6. Implant according to claim 5, characterized in that that the longitudinal grooves run parallel to each other. 7. Implant according to one of the preceding claims, characterized in that the spherical end ( 12 ) of the anchoring element ( 2 ) projects slightly into the cross section of the bearing recess ( 20 ). 8. Implant according to one of the preceding claims, characterized in that the bearing body ( 1 ) is plate-shaped. 9. Implant according to claim 8, characterized in that the bearing body ( 1 ) on its the Lagerausneh mung ( 20 ) facing away from the bottom protruding tips ( 23 , 24 ; 44 ). 10. Implant according to claim 9, characterized in that the tips ( 23 ) in the bearing body ( 1 ) are inserted. 11. Implant according to claim 9, characterized in that the tips ( 44 ) with the bearing body ( 1 ) are integrally formed. 12. Implant according to one of the preceding claims, characterized in that the bearing body (I) between the bearing recesses ( 20 ) carries on the pan-shaped receptacle ( 18 ) adjoining external thread sleeve ( 19 ) onto which the clamping element ( 27 ) can be screwed . 13. Implant according to one of the preceding claims, characterized in that the spherical end ( 12 ) of the anchoring element ( 2 ) has a non-circular central opening ( 14 ) as a receptacle for a turning tool ( 39 ). 14. Implant according to one of the preceding claims, characterized in that the anchoring element is a bone screw ( 2 ). 15. Implant according to claim 14, characterized in that the bone screw ( 2 ) is hollow. 16. Implant according to claim 15, characterized in that the bone screw ( 2 ) has perforated wall areas ( 6 ). 17. Implant according to one of the preceding claims, characterized in that the spherical end ( 12 ) is detachably connected to the remaining anchoring element ( 4 ). 18. Implant according to claim 17, characterized in that the spherical end ( 12 ) is screwed into the rest of the anchor element Ver ( 4 ). 19. turning tool for screwing in an anchoring element with a non-circular central opening in one end, in particular according to claim 13, characterized in that it has a spherical head ( 42 ) whose cross section is so out of round that it with play in the non-circular central opening ( 14 ) in the anchoring element ( 2 ) is feasible so that insertion at various angles is possible, but that when the tool ( 39 ) is rotated in the central opening ( 14 ) it engages in a positive engagement with the non-circular Cross section of the central opening ( 14 ) experiences. 20. Tool for inserting an implant according to claim 12 and optionally according to claims 13 to 18, characterized in that it comprises an insertable into the external thread sleeve ( 19 ) or a screwable sleeve ( 29 ). 21. Tool according to claim 20, characterized in that on the sleeve ( 29 ) on this longitudinally displaceable and rotatable relative to this, a screw sleeve ( 30 ) is attached, which has a positive receptacle ( 31 ) for the clamping element ( 27 ) at the lower end. and in an area above it has an attack surface ( 31 ) for a rotary tool ( 33 ). 22. Tool according to claim 21, characterized in that the screw-in sleeve ( 30 ) is shorter than the sleeve ( 29 ) which can be inserted into the externally threaded sleeve ( 19 ).