Set for the Endoscopic Fixation of an Implant in an Intervertebral Disk by Means of a Nail or Pin

Abstract

The invention relates to a set for the endoscopic fixation of an implant by means of a nail or pin. It comprises the following: an applicator sheath insertable through an endoscope into an intervertebral disk and through which an implant is insertable into an intervertebral disk defect; a drill wire guide sheath sized to be insertable into the applicator sheath; and a pusher for imparting blows during the fixation of an implant in the intervertebral disk by means of a nail or pin, wherein the pusher being sized to be insertable into the applicator sheath. In addition, the set may comprise an implant and or at least one nail or pin.

Claims

1. A set for the endoscopic fixation of an implant in an intervertebral disk by means of a nail or pin comprising: an applicator sheath (1) which is insertable through an endoscope into an intervertebral disk and through which an implant is insertable into an intervertebral disk defect; a drill wire guide sheath (2) sized to be insertable into the applicator sheath (1); and a pusher (3) for mediating blows during fixation of an implant in the intervertebral disk by means of a nail or pin, wherein the pusher (3) being sized to be insertable into the applicator sheath (1).

2. The set according to claim 1, wherein the applicator sheath (1) comprises a beveled tip (11), a hollow cylindrical main part (12) and a flange-like end piece (13).

3. The set according to claim 2, wherein the beveled tip (11) comprises two tip ends (21, 22) formed by recesses (17, 18) in the applicator sheath (1); and/or wherein the tip (11) of the applicator sheath (1) is rotationally asymmetrically beveled with respect to the longitudinal axis (X) of the applicator sheath (1).

4. The set according to claim 3, wherein the beveled tip (11) is rotationally asymmetrically beveled with respect to the longitudinal axis (X) of the applicator sheath (1) and has two tip ends (21, 22); and wherein both tip ends (21, 22) and at least one line passing therethrough which is parallel with respect to the longitudinal axis (X) of the applicator sheath (1) define at least one tip plane (E1, E2); wherein, with respect to a tip plane (E1), an upper bevel (14) of the tip (11) is geometrically described by an intersection with an upper plane (14) inclined at an upper acute angle α with respect to said tip plane (E1); and/or wherein, with respect to the same or a further tip plane (E2), a lower bevel (15) of the tip (11) is geometrically described by an intersection with a lower plane (15) inclined at a lower acute angle β with respect to said tip plane (E2).

5. The set according to claim 4, wherein for the upper acute angle α the following applies: 20°≤α≤30°, in particular α=25°; and/or wherein for the lower acute angle β the following applies: 20°≤β≤30°, in particular β=25°.

6. The set according to claim 3, wherein both tip ends (21, 22) have, in a direction orthogonal to the longitudinal axis (X) of the applicator sheath (1), a height h for which holds: 0.5 mm≤h≤1.5 mm, in particular h=1.0 mm.

7. The set according to claim 1, wherein the drill wire guide sheath (2) comprises a hollow cylindrical main part (201) and a flange-like end piece (202).

8. The set according to claim 1, wherein the pusher (3) comprises, optionally a mandrel (301) at its proximal end; a cylindrical main part (302) and a pusher header (303) at its distal end; and/or wherein for a length LSK of the pusher header (303) along the longitudinal axis (Z) of the pusher (3) the following applies: 13 mm≤LSK≤17 mm, in particular LSK=15 mm; and/or wherein for an outer diameter DSK of the pusher header (303) the following applies: 8 mm≤DSK≤12 mm, in particular DSK=10 mm; and/or wherein for the length LD of the mandrel (301) along the longitudinal axis (Z) of the pusher (3) the following applies: 1.9 mm≤LD≤2.1 mm, in particular LD=2.0 mm; and/or wherein for the outer diameter DD of the mandrel (301) the following applies: 0.9 mm≤DD≤1.1 mm, in particular DD=1.0 mm.

9. The set according to claim 1, wherein for an outer diameter DA of the applicator sheath (1) the following applies: 3.9 mm≤DA≤4.1 mm, in particular DA=4.0 mm; and wherein for an inner diameter dA of the applicator sheath (1) the following applies: 3.3 mm≤dA≤3.5 mm, in particular dA=3.4 mm; and wherein for an outer diameter DB of the drill wire guide sheath (2) the following applies: 2.9 mm≤DB≤3.1 mm, in particular DB=3.0 mm; and wherein for an inner diameter dB of the drill wire guide sheath (2) the following applies: 2.3 mm≤dB≤2.5 mm, in particular dB=2.4 mm; and wherein for an outer diameter DS of the pusher (3) the following applies: 2.9 mm≤DS≤3.1 mm, in particular DS=3.0 mm.

10. The set according to claim 1, wherein for a length LA of the applicator sheath (1) the following applies: 215 mm≤LA≤290 mm; and wherein for a length LB of the drill wire guide sheath (2) the following applies: 210 mm≤LB≤285 mm; and wherein for a length LS of the pusher (3) the following applies: 220 mm≤LS≤305 mm; and wherein further the following applies: LB<LA<LS; and wherein the specified lengths LA, LB and LS are determined in the case of the presence of a flange-like end piece (13, 202) or a header (303) at the respective component (1, 2, 3) without the respective flange-like end piece (13, 202) or without the header (303).

11. The set according to claim 2 or 7, wherein for a length LFA of a flange-like end piece (13) of the applicator sheath (1) along the main axis (X) of the applicator sheath (1) and for an outer diameter DFA of the flange-like end piece (13) of the applicator sheath (1) the following applies: 2.9 mm≤LFA≤3.1 mm, in particular LFA=3 mm, as well as 9 mm≤DFA≤11 mm, in particular DFA=10 mm; and/or wherein for a length LFB of a flange-like end piece (202) of the drill wire guide sheath (2) along the main axis (Y) of the drill wire guide sheath (2) and for an outer diameter DFB of the flange-like end piece (202) of the drill wire guide sheath (2) the following applies: LFB=LFA±0.1 mm, in particular LFB=3 mm, as well as DFB DFA, in particular DFB=12 mm.

12. A set according to claim 1, wherein the components of the set are reusable after appropriate sterilization.

13. The set according to claim 1, which furthermore comprises the following: a drill wire, in particularly a K wire, for predrilling a hole through an implant into the osseous part of a vertebral body.

14. The set according to claim 1, which furthermore comprises the following: an implant for placing in an intervertebral disk.

15. The set according to claim 14, wherein the implant is porous, spongy, compact, a felt, a fleece or mesh-like.

16. The set according claim 14, wherein the implant comprises at least one of the following materials: collagen; hyaluronan (hyaluronic acid); polyglycolic acid, polylactic acid and/or their respective copolymers; polycaprolactone; a natural membrane, in particularly periosteum, perichondrium and/or fasciae, as well as their modifications; alginate; agarose; fibrin; albumin containing material; polysaccharides as well as combinations thereof.

17. The set according to claim 1, which furthermore comprises the following: at least one, preferably resorbable and/or (X-ray) radiopaque, nail or pin for the fixation of an implant in an intervertebral disk.

18. The set according to the preceding claim 17, wherein the, preferably resorbable, nail or pin has a diameter DN for which the following applies: 1.4 mm≤DN≤1.6 mm, in particular DN=1.5 mm; and/or wherein the resorbable and/or (X-ray) radiopaque nail or pin has a length LN for which the following applies: 10 mm≤LN≤30 mm.

19. The set according to claim 1, wherein the applicator sheath (1) can be plugged onto an endoscope; and/or wherein no further fastening, in particular no screw connection, is required for the connection between an endoscope and the applicator sheath (1); and/or wherein the applicator sheath (1) does not comprise a separate holder or handle.

20. A method for endoscopic fixation of an implant in an intervertebral disk comprising the steps of: (i) inserting an applicator sheath into an intervertebral disc defect through an endoscopic port; (ii) inserting an implant through the applicator sheath into the intervertebral disc defect; (iii) inserting a drill wire guide sheath into the applicator sheath; (iv) drilling a hole through the implant into an adjacent vertebral body; (v) removing the drill wire guide sheath from the applicator sheath; (vi) inserting an attachment device into the applicator sheath to the hole; (vii) driving the attachment device (nail or pin) by a pusher into the hole in the vertebral body (viii) affixing the implant in the vertebra body by a securing device of the attachment device (nail or pin head).

21. The method of claim 20, wherein the angle to the drill hole should no longer be changed after step (iv).

22. The method of claim 20, wherein the attachment device is a resorbable nail or pin.

23. The method of claim 20, wherein the securing device of the attachment device is a nail or pin head.

24. The method of claim 20, wherein driving the attachment device by the pusher is accomplished in a rhythm of short hammer blows.

25. A surgical kit comprising an applicator sheath which is insertable through an endoscope into an intervertebral disk and through which an implant is insertable into an intervertebral disk defect; a drill wire guide sheath sized to be insertable into the applicator sheath; and a pusher for mediating blows during fixation of an implant in the intervertebral disk by means of a nail or pin, wherein the pusher being sized to be insertable into the applicator sheath, wherein the surgical kit, once assembled and in use, permits an operator to apply a endoscopic fixation of an implant in an intervertebral disk force in a first direction to vertebrae during a surgical procedure, wherein the applicator sheath, drill wire guide and pusher are surgical instruments and are not part of a construct configured to be implanted in, on or remain attached to a patient, but rather are configured to be temporarily engaged with the nail or pin (attachment device) during the surgical procedure, used to apply forces to the nail or pin (attachment device) during the same surgical procedure, and removed from the nail or pin (attachment device) and the patient during the same surgical procedure.

Description

[0083] FIG. 1: shows an applicator sheath of a set according to the present invention;

[0084] FIG. 2: shows a drill wire guide sheath of a set according to the present invention;

[0085] FIG. 3: shows a pusher of a set according to the present invention;

[0086] FIG. 4: shows a table with typical dimensions of an applicator sheath, a drill wire guide sheath and a pusher for a set according to the present invention;

[0087] FIG. 5: shows exemplary dimensions including tolerances for a set according to the present invention with applicator sheath, drill wire guide sheath and pusher.

[0088] FIG. 1 shows exemplarily an applicator sheath 1 of a set according to the present invention for the endoscopic fixation of an implant in an intervertebral disk by means of a nail or pin.

[0089] Thereby, FIG. 1a) shows a lateral sectional view of the applicator sheath 1 through the longitudinal axis X. FIG. 1b) shows a sectional view through the longitudinal axis X rotated by 90° to it in plan view. The applicator sheath 1 has a hollow cylindrical main portion 12, wherein a beveled tip 11 is disposed at the proximal end of the applicator sheath 1. At the distal end of the hollow cylindrical main portion 12 is a flange-like end piece 13. The beveled tip 11 is generated by recesses 18 and 19 in the cylindrical shell of the hollow cylindrical main portion 12.

[0090] The geometric relationships are shown in more detail in FIG. 1a). The beveled tip 11 has two tip ends 21 and 22. In FIG. 1a), these two tip ends lie congruently one behind the other, so that only the tip end 22 can be seen in the illustration in FIG. 1a). The two tip ends 21, 22 each have a tooth of height h, which is formed by the termination of the cylinder jacket of the applicator sheath 1. The beveled tip 11 is rotationally asymmetrically beveled with respect to the longitudinal axis X of the applicator sheath 1.

[0091] In the example shown in FIG. 1a), the two teeth 21, 22 therefore lie below the longitudinal axis X of the applicator sheath 1. The two tip ends 21, 22 and parallels to the longitudinal axis X of the applicator sheath 1 running through them define tip planes E1, E2. The planes E1 and E2 are mentally defined at the upper end of the tip ends 21, 22 and at the lower end of the tip ends 21, 22, respectively. With reference to the tip plane E1, an upper bevel 14 of the tip 11 is geometrically described by an intersection with an upper plane 14 inclined at an upper acute angle α with respect to this tip plane E1. Furthermore, with respect to the tip plane E2, a lower bevel 15 of the tip 11 is geometrically described by a section with a lower plane 15 inclined at a lower acute angle β with respect to the tip plane E2. The result of the performed cut is the recesses 18 and 19, which can be best seen in FIG. 1b).

[0092] FIG. 1 further shows the inner and outer diameters of the applicator sheath 1. The effective length LA of the applicator sheath 1 results in the direction of the longitudinal axis measured from the tip end to the beginning of the flange-like end piece 13. The flange-like end piece has a correspondingly larger outer diameter DFA as well as an additional length LFA. The inner diameter in the flange-like end piece 13 is the same as inside the hollow cylindrical main part 12.

[0093] FIG. 2 shows a drill wire guide sheath 2 of the set according to the present invention for the endoscopic fixation of an implant in an intervertebral disk by means of a nail or pin. The drill wire guide sheath 2 comprises a hollow cylindrical main part 201 as well as a flange-like end piece 202.

[0094] The drill wire guide sheath 2 has an inner diameter dB and an outer diameter DB. The effective length LB of the drill wire guide sheath 2 is preferably somewhat shorter than the effective length LA of the applicator sheath 1 in FIG. 1. The drill wire guide sheath 2 of FIG. 2 has an opening 203 at its proximal end. At its distal end, it has an opening 204 in the flange-like end piece 202 of the drill wire guide sheath 2.

[0095] Here, in the example shown, the outer diameter DFB of the drill wire guide sheath 2 is slightly larger than the outer diameter DFA of the flange-like end piece 13 of the applicator sheath 1. This enables easier separation of the drill wire guide sheath 2 and the applicator sheath 1 after the two stop units have been in contact with each other.

[0096] FIG. 3 shows a pusher for a set for the endoscopic fixation of an implant in an intervertebral disk. The pusher 3 shown is formed in one piece and comprises two or three different functional areas: An optional mandrel 301 at the proximal end, which may or may not be present depending on the embodiment, a cylindrical main part 302, as well as a pusher head portion 303 at the distal end. In the example shown, the pusher is formed to be completely compact, which allows for better transmission of force or pressure when imparting blows or hammer blows for fixation. The outer diameter DS of the pusher 3 and its cylindrical main part 302, respectively, is adjusted to the inner diameter dA of the applicator sheath 1.

[0097] Compared to this, the outer diameter DD of the mandrel is much smaller and also the length LD of the mandrel along the longitudinal direction or axial direction Z of the pusher 3 is extremely short and is only a few millimeters. The pusher head 303, on the other hand, is provided with a large outer diameter DSK and has a length LSK in the range of a few millimeters. Thus, the pusher head portion 303 is sufficiently large and solidly formed to be sufficiently stable when struck and to present a surface for the percussion instrument that is perpendicular to the longitudinal axis Z and large enough to be a target for blows.

[0098] The use of a set according to the invention for endoscopic fixation of an implant in an intervertebral disc by means of a nail or pin during an operation can be performed, for example, as follows: First, the applicator sheath 1 is inserted into the intervertebral disc through an endoscopic port. Subsequently, the implant is inserted through the applicator sheath 1 into the intervertebral disc defect, for example using grasping forceps. After removing the grasping forceps, the drill wire guide sheath 2 is inserted into the applicator sheath 1. By means of a drill wire, in particular a K-wire, a hole is drilled through the implant into the osseous part of the adjacent vertebral body. Subsequently, the drill wire is pulled out and the drill wire guide sheath 2 is also pulled out of the applicator sheath 1. At the same time, the angle to the drill hole should no longer be changed. In a next step a resorbable nail or pin is introduced into the applicator sheath 1 which slides through the sheath 1 up to the predrilled hole. By means of the inserted pusher 3, the nail can be driven into the pre-drilled hole in the vertebral body under short hammer blows. Thus, the head of the nail fixes the implant in the intervertebral disc

[0099] The length ratios of applicator sheath 1, drill wire guide sheath and pusher 3 are matched to each other, and the same applies to their inner and outer diameters. The parts of the set shown in the FIGS. 1, 2 and 3 can be combined with each other in the manner shown.

[0100] FIG. 4 summarizes the length relationships and coordinated inner and outer diameters of applicator sheath 1, drill wire guide sheath 2 and pusher 3 in a corresponding overview once again. Here, the drill wire guide sheath 2 is slightly shorter than the applicator sheath 1 (LB slightly shorter than LA). On the other hand, the pusher 3 is correspondingly longer (LS>LA). The drill wire guide sheath 2 and the pusher 3 can be inserted one after the other into the applicator sheath 1. Accordingly, the outer diameters DB of the drill-wire guide sheath and DS of the pusher 3 in the example shown are the same at 3.0 mm. The wall thicknesses of applicator sheath 1 and drill wire guide sheath 2 are only a few tenths of a millimeter each. In contrast, the pusher 3 is of compact design.

[0101] FIG. 5 shows for a further exemplary embodiment variant dimensions and tolerances of applicator sheath 1, drill wire guide sheath 2 and pusher 3. The specified tolerances are permissible manufacturing tolerances which do not impair the functioning of the set according to the present invention. Here, the highest accuracy is required for the inner diameter dA of the applicator sheath 1 and the inner diameter dB of the drill wire guide sheath 2.

[0102] Here, manufacturing should be accurate to the tenth of a millimeter. The tolerance range for the outer diameter DB of the drill wire guide sheath 2 is slightly larger and is +0.04 mm. The same applies to the outer diameter DS of the pusher 3. Only then can it be ensured that the drill wire guide sheath 2 and/or the pusher 3 can be pushed through or inserted into the applicator sheath 1 without jamming or friction effects.

[0103] With the aid of the invention, it has been possible for the first time to provide a set for endoscopic fixation of an implant in an intervertebral disc by means of a nail or pin. It is hoped that this will result in significantly better long-term maintenance of the disc height during disc surgery.