IMPLANT FOR SEALING A DEFECT IN THE ANULUS FIBROSUS OF AN INTERVERTEBRAL DISC

Abstract

The invention relates to an implant (1) for sealing a defect (7c) in the annulus fibrosus (7a) of an intervertebral disc (7), comprising a retaining portion (3) for introducing into the defect (7c), a flexible sealing element which is connected to an inner end of the retaining portion, and a securing element (2) which is connected to the outer end of the retaining portion and which can be fixed to a vertebra (8) adjoining the intervertebral disc in order to hold the retaining portion (3) in a fixed position. According to the invention, this is achieved in that a securing limb (2), which is angled relative to the longitudinal axis of the retaining portion, is arranged on the outer end of the retaining portion (3), said securing limb being designed for laterally contacting a bony structure of a vertebra adjacent to the intervertebral disc and being securable on the vertebra by means of a fixing element which can be moved relative to the securing limb. The sealing element has inner reinforcements.

Claims

1-16. (canceled)

17. An implant for sealing a defect in an anulus fibrosus of an intervertebral disc, with a retaining portion for insertion into the defect, a flexible sealing element connected to an inner end of the retaining portion and a securing limb, connected to the outer end of the retaining portion, which can be fixed to a vertebra adjoining the intervertebral disc, in order to hold the retaining portion in a fixed position, wherein the flexible sealing element has internal reinforcements, wherein the flexible sealing element has a reduced projected area in a top view from a front along a longitudinal axis of the retaining portion in a first state and has a widened projected area, which is at least twice the reduced projected area, in a second state, wherein the securing limb is angled relative to the longitudinal axis of the retaining portion and is arranged on the outer end of the retaining portion, which securing limb is designed to be laid laterally against a bony structure of the vertebra adjoining the intervertebral disc and can be secured to the vertebra with the aid of a fixing element which is movable relative to the securing limb.

18. The implant according to claim 17, wherein, at a distance from the retaining portion, the securing limb has a cross hole for the fixing element, to be anchored in the vertebra, to be guided through.

19. The implant according to claim 18, wherein the cross hole is inclined relative to the longitudinal direction of the retaining portion at an angle in a range of from 0 to 30.

20. The implant according to claim 18, wherein an adapter sleeve is provided which can be inserted into the cross hole and which itself has a hole, the axis of which is inclined relative to a longitudinal axis of the cross hole at an angle in the range of from 0 to 30.

21. The implant according to claim 20, wherein the adapter sleeve is pre-installable in the cross hole.

22. The implant according to claim 17, wherein the fixing element is selected from the group consisting of: a nail, a screw, a screw anchor with a screw and a secured screw with an expansion anchor.

23. The implant according to claim 17, wherein the securing limb and the retaining portion are formed in one piece.

24. The implant according to claim 17, wherein the securing limb and the retaining portion are connected to each other in a detachable manner.

25. The implant according to claim 17, wherein the securing limb and the retaining portion are connected to each other in an articulated manner.

26. The implant according to claim 17, wherein, on the inner end of the retaining portion, the sealing element is a fothering that can be spread out which projects beyond a cross-sectional area of the retaining portion on all sides in a top view onto an end face of the retaining portion in its spread-out state and is provided to seal the defect on an inner side of the anulus fibrosus.

27. The implant according to claim 26, wherein the fothering has integrated rod- or wire-shaped reinforcements, which either provide a pretension in the direction of the spread-out state or make it possible to spread out the fothering by manipulation of the reinforcements from outside.

28. The implant according to claim 26, wherein the fothering has at least two segments, wherein neighbouring segments are connected to each other at least in portions and/or overlap in portions in a spread-out state of the fothering.

29. The implant according to claim 26, wherein each segment of the fothering is designed leaf-shaped and has a longitudinal axis extending up to a leaf tip, and wherein the longitudinal axes of two neighbouring segments form an angle of from 10 to 120 in a spread-out state of the fothering.

30. The implant according to claim 26, wherein each segment of the fothering is designed leaf-shaped and has a longitudinal axis extending up to a leaf tip, and wherein the longitudinal axes of two neighbouring segments form an angle of from 45 to 90 in a spread-out state of the fothering.

31. The implant according to claim 26, wherein an actuation means, which is connected to the fothering and brings about the spreading-out of the fothering by actuation, is guided through the retaining portion from its outer to its inner end.

32. The implant according to claim 31, wherein the actuation means, together with reinforcements of the fothering, forms an inverse umbrella mechanism.

33. The implant according to claim 17, wherein the retaining portion has a through hole, extending from its outer to the inner end, which is sealed by an elastic, pierceable plug.

34. The implant according to claim 33, wherein the plug consists predominantly of silicone.

35. The implant according to claim 33, wherein the plug has a thickness of at least 2 mm in the direction of the through hole of the retaining portion.

36. The implant according to claim 33, wherein the plug has a thickness of at least 5 mm in the direction of the through hole of the retaining portion.

Description

DESCRIPTION OF EMBODIMENT EXAMPLES

[0049] Further advantages, features and possible applications of the present invention will become clear with reference to the following description of preferred embodiments and the associated figures. There are shown in:

[0050] FIG. 1: a schematic, perspective view of an implant according to an embodiment of the present invention;

[0051] FIG. 2: a side view of the implant according to the invention according to FIG. 1;

[0052] FIG. 3: different variants of the arrangement of retaining portions and securing limb;

[0053] FIG. 4: two variants of securing limbs;

[0054] FIG. 5: a longitudinal section through an intervertebral disc with an implant according to the invention according to FIG. 1;

[0055] FIG. 6: a top view onto the inner side of an implant according to an embodiment of the present invention with a spread-out fothering;

[0056] FIG. 6a: a superelevated cross section A-A through the fothering in FIG. 6;

[0057] FIGS. 7a,b: the arrangement and position of the implant after introduction into an intervertebral disc;

[0058] FIGS. 8a-c: side views of an implant according to the present invention with an unfolding mechanism, actuatable from outside, for a fothering in different unfolding states;

[0059] FIGS. 9a-c: an implant with a securing limb for the anti-twist receiving of fixing elements.

[0060] All figures are only of a schematic nature with regard to dimensions and dimensional ratios and the precise outline shapes. In particular, sharp edges and transitions in the embodiments represented can in reality be shaped differently and e.g. rounded.

[0061] A perspective view of an implant 1 according to an embodiment of the invention is represented in FIG. 1. In a side view, the implant 1 has an L-shaped article 20 with a securing limb 2 which has a continuous hole 5 as well as an inner side 2a (not visible in FIG. 1) and, opposite this, an outer side 2b. The other limb of the L-shaped article 20 forms the retaining portion 3, which is designed for insertion into a defect in the anulus fibrosus of an intervertebral disc. A fothering 4 that can be spread out, which is indicated in its closed, folded state in FIG. 1, is arranged on the inner end 3a of the retaining portion 3. The retaining portion 3 can have a central longitudinal hole 9a for receiving a plug, not represented here.

[0062] The hole 5 for receiving a fixing element 6 (not represented in FIG. 1), which extends through the securing limb 2 from the outer side 2b to the inner side 2a and, in the implanted state, into an adjoining vertebra, extends in an area, spaced apart from the retaining portion 3, of the securing limb 2 which is designed to be laid with its inner side 2a laterally against a bony structure of a vertebra neighbouring the intervertebral disc to be sealed, more precisely against its circumferential surface.

[0063] FIG. 2 shows an implant in a side view, with reference to which different characteristics and dimensions of the implant can be explained. The angle between the longitudinal extent of the retaining portion and the longitudinal extent of the securing limb 2 is designated and can be between 70 and 130 degrees. The angle between the axis of the hole 5 and the longitudinal extent of the retaining portion 2 is independent of the angle and can adopt e.g. values between 0 and 60 degrees.

[0064] FIGS. 3 and 4 show side and rearward (from the outer side 2b) views of different variations of retaining elements 3 and securing limbs 2. As can be seen, the angle between securing limb 2 and retaining portion 3 can vary and the angle of the axis of the hole 5 relative to the securing limb 2 or to the retaining portion 3 can also vary and does not necessarily run parallel to the longitudinal direction of the retaining portion 3.

[0065] FIG. 4 is a top view from outside along the longitudinal axis of the retaining portion which substantially corresponds to the direction of insertion of the retaining portion into the defect 7c. It can be seen that the securing limb 2 can adopt different shapes, wherein it substantially depends on its possible positioning on a vertebra 8 and the fixing thereto, which is preferably realized here with the aid of a hole 5 and fixing elements 6 extending through this.

[0066] The length L1 of the retaining portion 3 typically lies between 3 and 10 mm and the length L2 of the securing limb 2 also lies in this order of magnitude or slightly above it. The size of the securing limb 2 is dimensioned in particular such that, at a distance from the end plate of the vertebra adjoining the intervertebral disc, it has securing elements, in this case in the form of the hole 5 and for example a screw 6 with a screw anchor 16, as represented in FIG. 5.

[0067] FIG. 5 shows a similar embodiment in a schematically represented state inserted into an intervertebral disc 7 in a cross section through the intervertebral disc 7 perpendicular to its plane in the area of a defect 7c.

[0068] The intervertebral disc 7 indicated has a defect 7c, through which the nucleus pulposus 7b can escape, in its anulus fibrosus 7a. The retaining portion 3 is inserted into the defect 7c to seal the defect 7c. The retaining portion 3 and also the folded fothering 4 in every case have a smaller cross section than the defect 7c, in order that the retaining portion 3 can be inserted into the defect 7c with the folded fothering 4 at the front. The fothering 4 in its unfolded or spread-out state is represented on the inner end 3a of the retaining portion 3. In the spread-out state, the fothering 4 nestles up against the anulus fibrosus from the inside and thus seals the defect 7c in the anulus fibrosus 7a. The intervertebral disc internal pressure prevailing in the jelly-like substance of the nucleus pulposus 7b presses the fothering 4 against the anulus fibrosus 7a from the inside.

[0069] In its spread-out state and in a top view onto the inner end of the retaining portion 3, the fothering 4 extends clearly beyond the cross-sectional area of the retaining portion 3 and also well beyond the cross section of the defect 7c. In this way the fothering 4 can adhere extensively to the intervertebral disc and take, and thus also has a good hold in the intervertebral disc 7. The retaining portion 3 and also the securing limb 2 are then no longer needed and can therefore also consist of a material that can be gradually resorbed by the human body, such as for example polylactide or iron-tricalcium phosphate.

[0070] As can be seen in the view according to FIG. 5, the area of the securing limb 2 designed to be laid laterally against a bony structure of a neighbouring vertebra 8 has a hole or through hole 5 for receiving a screw 6. The hole 5 extends from the outer side 2b of the securing limb 2 to the inner side 2a and also has a stepwise widening 5a on the outer side for receiving a screw head 6a. The fixing element here is thus a screw, which has a head portion 6a and a threaded portion 6b. The head portion 6a is received in the stepwise widening 5a, while the threaded portion 6b of the fixing element is screwed into the bone of the vertebra 8, specifically into an expansion anchor 9 in a hole introduced into the vertebra 8.

[0071] Through this lateral securing of the implant 1 with the fixing element 6, among other things the need to insert a securing element into the intervertebral disc space, which could damage the end plates 8a of neighbouring vertebrae 8 in an undesired manner, is avoided. The position and orientation of the retaining portion 3 is defined by the fixing of the securing limb 2 on the vertebra 8. The height of the retaining portion 3 (measured between opposite end plates of neighbouring vertebrae 8) is in every case much smaller than the height of the intervertebral disc, which determines the distance between the end plates. It is thereby avoided that, after any further degeneration of the intervertebral disc 7, the implant or the retaining portion 3 comes into contact with the end plates of the vertebrae 8 on both sides and further restricts the mobility thereof and/or causes pain.

[0072] An embodiment of an implant 1 of the present invention is shown in a top view onto the end face of the retaining portion 3 with a freely spread-out fothering 4 in FIG. 6. In the freely spread-out state, the fothering would extend beyond the upper and lower boundary planes of the intervertebral disc 7 indicated by dashed lines 7e. The prongs of the segments 4a, 4b and 4c are therefore bent after insertion such that they lie within the boundaries defined by the lines 7e. Of course, from the outset the fothering can also have smaller outer dimensions, which, in the freely spread-out state, lie within the expected boundary lines or have at least a smaller protrusion than represented here. The fothering 4 thus protrudes beyond the cross-sectional area of the retaining portion 3 and above all also beyond the cross section of a defect 7c in the top view onto the end face of the retaining portion 3. The fothering 4 is manufactured, in one piece, from PTFE.

[0073] For an automatic spreading-out of the fothering 4, pretensioned reinforcements 4d, e.g. made of spring steel, are incorporated into the fothering 4, as can be seen from the superelevated cross section, shown in FIG. 6a, through the fothering 4 along the line A-A. For example, the reinforcement 4d could consist of a ring-shaped wire which is forced into the shape represented in FIG. 4 and is thereby integrated into the fothering 4 under pretension, wherein the fothering 4 is additionally folded for introduction through the defect and spreads out to the represented shape after passing through the defect.

[0074] As is likewise indicated in FIG. 6, the securing limb 2 has an application port 9, which is formed as a perforable, elastic septum or a plug in a hole 9a extending lengthwise through the retaining portion 3. The hole 9a is sealed by the plug 9, with the result that a pointed hollow needle can pierce the plug 9 and then a flowable substance can be introduced into or drawn out of the inside of the intervertebral disc through the needle. After the hollow needle has been withdrawn, the pierced channel generated by the hollow needle automatically and completely seals itself because of the elasticity and internal adhesion of the plug material, wherein a hollow needle which, if possible, does not punch material out of the plug, but only dislodges the plug material is preferably used. In this way, for example, medicaments or therapeutic fluids can be introduced into the inside of the intervertebral disc without damaging the anulus fibrosus further. For diagnostic purposes as well, a fluid sample can be drawn from the inside of the intervertebral disc through the self-sealing plug.

[0075] FIGS. 7a and 7b indicate the position of the implant introduced into an intervertebral disc in a horizontal and a vertical section. The fothering 4 rests against the inner side of the anulus fibrosus 7a and extends clearly beyond the cross section of the defect 7c. The retaining portion supports the fothering in the area of the defect 7c, at least until the fothering has taken or been incorporated. The retaining portion 3 and also the securing limb 2, as well as optionally also the fixing element 6, can consist of a material that can be resorbed by a patient's body.

[0076] According to an embodiment of the present invention, an implant 1 is represented in a longitudinal section through the retaining portion 3 in FIGS. 8a-c. For the fothering 4, the implant 1 has an umbrella-like spreading-out mechanism 10a, 10b and a pull wire or thread 10c, which extends through the retaining portion 3 and one end of the securing limb 2 and is connected to two segments 4a (only indicated) of the fothering 4 such that the fothering 4 is spread out by a pull on the wire or thread 10c from the outer side 2b.

[0077] Each of the segments 4a has a reinforcement 4d, which is only indicated in FIG. 8 and which is connected, in each case with one strut 10a via an articulated connection 10b, to a pull rod 10d, the other end of which is connected to the pull thread or wire 10c. To illustrate the mode of operation of the spreading-out mechanism, the fothering 4 is represented in different opening positions in FIGS. 8a to 8c, wherein in FIG. 8a the fothering 4 is folded or closed, in FIG. 8b the fothering 4 is partially opened and in FIG. 8c the fothering is spread out completely. If the pull thread or wire is already held under pretension inside the defect 7c during introduction, the fothering unfolds as soon as it has passed through the defect 7c in the anulus fibrosus.

[0078] FIG. 9 shows a perspective view of a further embodiment of the present invention, in which the hole 5 in the securing limb 2 has positioning means in the form of edge recesses 5a which are arranged at spacings of 120 around a central hole. These edge recesses make it possible to receive a matching sleeve 6a, which has corresponding radial extensions 6c, and act as anti-twist protection for the sleeves 6a or 6b. Two corresponding sleeves 6a, 6b different from each other are represented in FIGS. 9b and 9c.

[0079] The edge recesses 5a and the radial extensions 6c make it possible to arrange the sleeves 6a, 6b in the central hole 5 in three different alignments, which is advantageous in particular when the sleeve itself has a hole 6g, the axis of which runs inclined relative to the axis 6h defined by the outer surface 6f of the sleeve 6a. The number and arrangement of the edge recesses 5a can, of course, be varied as desired in order to increase or reduce the number of possible orientations of the adapter sleeve 6a or 6b.

[0080] Fixing elements, such as for example screws, can thus be introduced into the vertebra from three different directions, depending on the alignment of the sleeve 6a and optionally a through hole through the sleeve, wherein the surgeon has the possibility of selecting the direction according to the smallest possible degree of injury to the bone parts and soft tissue lying on the path of access to the defect of the intervertebral disc. Alternatively, the edge recesses and extensions can act as anti-twist protection if, for example, the sleeve to be inserted into the hole 5 has a screw anchor lug 6d which extends into the bone material of the vertebra 8. A non-rotationally symmetrical screw head could also be secured against twisting with an additional sleeve, which is fitted onto the screw head on the one hand and at the same time locked into the hole 5 with the edge recesses 5a.

[0081] Examples of suitable sleeves 6a, 6b, such as can be used in some embodiments of the present invention for combination with an implant 1 according to the invention, are represented in FIGS. 9b and 9c.

[0082] For the purposes of original disclosure, it is pointed out that all features, as revealed to a person skilled in the art from the present description, the drawings and the claims, even if they were described specifically only in connection with particular further features, can be combined both individually and in any desired combinations with others of the features or feature groups disclosed here, unless this has been expressly ruled out or technical circumstances make such combinations impossible or pointless. The comprehensive, explicit representation of all conceivable combinations of features is dispensed with here only for the sake of the brevity and readability of the description.

LIST OF REFERENCE NUMBERS

[0083] 1 implant

[0084] 2 securing limb

[0085] 2a inner side of the securing limb

[0086] 2b outer side of the securing limb

[0087] 3 retaining portion

[0088] 3a end of the retaining portion

[0089] 4 fothering

[0090] 4 segment of the fothering

[0091] 4b segment tip

[0092] 4c longitudinal axis of the segment

[0093] 4d reinforcement

[0094] 5 hole for receiving a fixing element

[0095] 5a positioning means, edge recess

[0096] 6a sleeve

[0097] 6b sleeve

[0098] 6c extensions

[0099] 6d screw anchor, screw anchor lug

[0100] 6e screw, threaded shank

[0101] 6f outer wall of the adapter sleeve

[0102] 6g sleeve channel

[0103] 6h longitudinal axis of the sleeve channel

[0104] 7 intervertebral disc

[0105] 7a anulus fibrosus

[0106] 7b nucleus pulposus

[0107] 7c defect

[0108] 8 vertebra

[0109] 8a end plate

[0110] 9 application port, plug

[0111] 9a through hole, hole

[0112] 5 actuation means

[0113] 10a strut

[0114] 10b articulated connection

[0115] 10c pull rod