(19)
(11)EP 3 795 120 A1

(12)EUROPEAN PATENT APPLICATION

(43)Date of publication:
24.03.2021 Bulletin 2021/12

(21)Application number: 19198123.2

(22)Date of filing:  18.09.2019
(51)International Patent Classification (IPC): 
A61F 2/44(2006.01)
A61F 2/30(2006.01)
A61F 2/46(2006.01)
(84)Designated Contracting States:
AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR
Designated Extension States:
BA ME
Designated Validation States:
KH MA MD TN

(71)Applicant: Biedermann Technologies GmbH & Co. KG
78166 Donaueschingen (DE)

(72)Inventor:
  • BIEDERMANN, Timo
    78647 Trossingen (DE)

(74)Representative: Prüfer & Partner mbB Patentanwälte · Rechtsanwälte 
Sohnckestraße 12
81479 München
81479 München (DE)

  


(54)INTERVERTEBRAL IMPLANT AND INSERTION DEVICE THEREFOR


(57) An intervertebral implant includes a body configured to be inserted into an intervertebral space, a hollow space (10) provided in the body and configured to accommodate an engagement portion (111) of a drive shaft (110) of an insertion device (100) therein and being accessible from outside the body through an opening (11) in the sidewall (2), wherein the opening (11) is elongate so as to permit the intervertebral implant and the insertion device to pivot relative to each other around an axis of rotation (R) at least from a first angular position to a second angular position when the engagement portion (111) is within the hollow space (10), and wherein the intervertebral implant further comprises at least a first abutment surface (21) and a second abutment surface (22) which each configured to engage an abutment surface (123) formed at the insertion device (100) to provide a form-fit connection between the intervertebral implant (1, 1000) and the insertion device (100) when the insertion device (100) is tightened against the intervertebral implant in the first angular position or the second angular position.




Description


[0001] The invention relates to an intervertebral implant and an insertion device for such an intervertebral implant. The intervertebral implant and the insertion device may be used, for example, for spinal fusion in the case of a damaged intervertebral disk.

[0002] Lumbar or thoracic interbody fusion surgery is one of the most commonly performed instrumented spinal fusion surgeries. Among others, known surgical approaches for interbody fusion of the lumbar spine include posterior lumbar interbody fusion (PLIF), transforaminal lumbar interbody fusion (TLIF), anterior lumbar interbody fusion (ALIF), antero-lateral ALIF and lateral interbody fusion.

[0003] An intervertebral implant and a device for inserting the same that are, for example, suitable for TLIF are described in US 2017/0056194 A1. The intervertebral implant comprises a top surface, a bottom surface, and a sidewall extending between the top surface and the bottom surface and a hollow space formed within the intervertebral implant and accessible through an elongate opening extending through a recessed portion of the sidewall. The hollow space is shaped to receive an engagement portion of a drive shaft of an insertion tool. The intervertebral implant includes at least two guiding surfaces facing each other and being configured for sliding engagement by a portion of a sleeve of the insertion tool movably holding the drive shaft.

[0004] It is an object underlying the invention to provide an improved or alternative intervertebral implant and an insertion device therefor that has an enlarged field of application.

[0005] The object is solved by an intervertebral implant according to claim 1 and by a system including such an intervertebral implant and an insertion device according to claim 15. Further developments are given in the dependent claims.

[0006] The intervertebral implant is designed to permit a pivoting of the insertion device relative to the intervertebral implant and to lock the intervertebral implant relative to the insertion device in at least two pivot positions by a form-fit connection. Such a form-fit connection is more robust compared to a force-fit connection that is based on friction. This enhances the safety during insertion of the intervertebral implant where often large forces are needed.

[0007] Moreover, it is possible to insert the intervertebral implant in a fixed position defined by the form-fit connection with the insertion device and, if necessary, to adjust the position of the implant after releasing the form-fit connection and pivot the implant relative to the insertion device while the implant is still safely connected thereto. By means of such a procedure, corrections of the position of the implant can be made.

[0008] According to a further aspect, the intervertebral implant may comprise more than two different surfaces for defining different pivot angles for a form-fit connection between the intervertebral implant and the insertion device. Therefore, with a single intervertebral implant different access paths to the intervertebral space may be possible and different surgical techniques can be implemented. Hence the field of application of the intervertebral implant can be further enlarged.

[0009] According to a still further aspect, the intervertebral implant may comprise at least one guiding surface for pivoting of the intervertebral implant and the insertion device relative to each other along the guiding surface and frictional clamping of the implant and the insertion device with respect to each other at a particular position along the cooperating guiding surfaces.

[0010] According to a still further aspect, the intervertebral implant may comprise further receiving sections for receiving the insertion device in a non pivotable manner at other locations on the implant.

[0011] According to a still further aspect, the intervertebral implant can be a dummy implant or testing implant that is used for a trial procedure before inserting the intervertebral implant for permanent stay in a patient's body.

[0012] Thus, the intervertebral implant can be used for example for various surgical procedures, such as TLIF, ALIF,antero-lateral ALIF, PLIF, and lateral interbody fusion, but not restricted thereto,using one and the same intervertebral implant and insertion device. Due to the enlarged possibilities of connecting the implant to the insertion device, the implant may be particularly useful in the case of difficult anatomical circumstances such as in anterior and lateral approaches to the spine.

[0013] Further features and advantages will become apparent from the detailed description of embodiment by means of the accompanying drawings. In the drawings:
Fig. 1:
shows a perspective view of a system of an intervertebral implant according to a first embodiment with an insertion device connected thereto.
Fig. 2:
shows a perspective view of the intervertebral implant of Fig. 1 from one side which exhibits an elongate opening for connection with the insertion device.
Fig. 3:
shows a perspective view of the intervertebral implant of Figs. 1 and 2 from another side that exhibits a further opening for attachment of the insertion device.
Fig. 4:
shows a perspective view of a front portion of a drive shaft of the insertion device of Fig. 1.
Fig. 5:
shows a side view of the front portion of the drive shaft of Fig. 4.
Fig. 6:
shows a side view of the front portion of the drive shaft of Fig. 5 rotated by 90°.
Fig. 7:
shows a perspective view of a front portion of a guiding sleeve of the insertion device of Fig. 1.
Fig. 8:
shows a side view of the front portion of the sleeve of Fig. 7.
Fig. 9:
shows a side view of the front portion of the sleeve of Fig. 8 rotated by 90°.
Figs. 10a to 10c:
show perspective views of steps of connecting the front portion of the drive shaft of the insertion device of Figs. 4 to 6 to the intervertebral implant of Figs. 1 to 3.
Figs. 11a to 11d:
show cross-sectional views of steps of connecting the front portion of the insertion device to the intervertebral implant, wherein the section is taken in a plane extending through the intervertebral implant at half of its height of the side wall and through the longitudinal axis of the insertion device.
Fig. 12:
shows a perspective view of a form-fit engagement between the intervertebral implant and the insertion device wherein the insertion device forms an angle of substantially 45° with a longitudinal axis of the intervertebral implant.
Fig. 13:
shows a perspective view of a form-fit connection between the intervertebral implant and the insertion device, wherein the insertion device forms an angle of substantially 90° with a longitudinal axis of the intervertebral implant.
Fig. 14:
shows a perspective view of a form-fit connection between the intervertebral implant and the insertion device, wherein the insertion device forms an angle of substantially 0° with the longitudinal axis of the intervertebral implant.
Fig. 15:
shows a perspective view of a connection between the intervertebral implant and the insertion device wherein the insertion device is at a position relative to the intervertebral implant that permits rotating and clamping the intervertebral implant by friction.
Fig. 16:
shows a cross-sectional view of the connection between the intervertebral implant and the insertion device forming an angle of substantially 90° as shown in Fig. 13.
Fig. 17:
shows a cross-sectional view of the connection between the intervertebral implant and the insertion device forming an angle of substantially 0° as shown in Fig. 14.
Fig. 18:
shows a cross-sectional view of the connection between the intervertebral implant and the insertion device that permits to assume various intermediate positions and to frictionally clamp the implant and the insertion device at the intermediate positions as shown in Fig. 15.
Fig. 19:
shows a perspective view of the intervertebral implant with the insertion device connected to a further receiving portion.
Fig. 20:
shows a cross-sectional view of the intervertebral implant with the insertion device of Fig. 19.
Fig. 21:
shows a perspective view of the intervertebral implant with the insertion device connected to a still further receiving portion.
Fig. 22:
shows a cross-sectional view of the intervertebral implant with the insertion device of Fig. 21.
Fig. 23:
shows a perspective view of a further modified embodiment of the intervertebral implant that is formed as an ALIF intervertebral implant.
Fig. 24:
shows a perspective view of the intervertebral implant of Fig. 23 with the insertion device attached thereto.
Fig. 25:
shows a perspective view from the top of the intervertebral implant and the insertion device of Fig. 24.


[0014] Fig. 1 shows a perspective view of an intervertebral implant and an insertion device 100 for inserting the intervertebral implant 1 into an intervertebral space. The intervertebral implant 1 comprises a body including a substantially vertical sidewall 2 defining a height extension of the intervertebral implant 1. The sidewall 2 is formed monolithically with an inner solid portion 3 and encloses one or more inner hollow spaces 4. The hollow spaces 4 are open towards an upper face 5a and a lower face 5b of the intervertebral implant 1.

[0015] More in detail, the sidewall 2 is composed of a front wall 2a, an opposite back wall 2b, a right sidewall 2c and a left sidewall 2d which are monolithically formed, such that the right and left sidewall connect the front wall 2a and the back wall 2b with each other. The front wall 2a represents an anterior wall and the back wall 2b represents a posterior wall of the intervertebral implant 1. The front wall 2a and the back wall 2b may be longer than the right sidewall 2c and the left sidewall 2d, so that the intervertebral implant has an elongate outer contour. In the embodiment, the front wall 2a and the back wall 2b are substantially parallel to each other and define a longitudinal central axis LI of the intervertebral implant (indicated in Fig. 11a). Optionally, inner walls 6a, 6b may extend in an arc-shaped manner from the front wall 2a to the back wall 2b. Both inner walls 6a, 6b may be symmetric with respect to a sagittal plane S (indicated in Fig. 11a) that extends through a center of the front wall 2a and the back wall 2b in the height direction. The solid portion 3 extends from the front wall 2a to a distance from the back wall 2b. It has such a length from the front wall 2a towards the back wall 2b that receiving portions in the form of recesses as described below can be formed in the solid body 3 with a sufficient depth for engagement with the insertion device 100. The sidewall 2 may have such a height that the top surface 5a and the bottom surface 5b extend above the solid portion 3.

[0016] The hollow spaces 4 are configured to be filled with bone graft material. Further, engagement portions, for example teeth 7, may be provided on the upper face 5a and the lower face 5b of the intervertebral implant which may facilitate a penetration into the end plates of adjacent vertebral bodies. The front wall 2a and the back wall 2b may have a different height such that the top face 5a and the bottom face 5b form an angle resulting in a wedge shape of the intervertebral implant 1.

[0017] As can be seen in detail in particular in Fig. 2, at the transition of the front wall 2a to the right sidewall 2c a recess 10 is provided that forms an elongate opening 11 in the sidewall 2. The recess 10 defines a hollow space within the intervertebral implant 1 for receiving a portion of the insertion device. It extends into the solid portion 3 and forms a corner with an angle of substantially 90° degrees therein. Thereby, left and right end walls of the recess 10 form an angle of substantially 90°. The recess 10 and therewith the opening 11, may be provided at the middle of the sidewall 2 in the height direction of the intervertebral implant 1.

[0018] A width of the recess 10 in the height direction of the intervertebral implant 1 is such, that an engagement portion of the insertion device can be introduced in one orientation but cannot be introduced in a tilted orientation. Top and bottom walls of the recess 10 may be planar and may extend substantially parallel to each other and substantially perpendicular to the sidewall 2. The opening 11 extends in a circumferential direction from the front wall 2a over a corner between the front wall 2a and the right sidewall 2c into the right sidewall 2c. Hence, the elongate opening 11 and the recess 10 have such a size that the drive shaft of the insertion device can assume an angle of 0° and an angle of 90° with the central longitudinal axis LI of the intervertebral implant 1.

[0019] In the inside corner of the recess 10, a spherically-shaped recess 12 is formed that is configured to pivotably receive the engagement portion of the insertion device 100. A radius of the spherically-shaped recess 12 matches a radius of an outer surface of the engagement portion of the drive shaft. The spherical recess 12 has such an extension that it permits the engagement portion of the insertion device to pivot therein in an angular range of about 90° or more. An axis R extending through a center of the spherically-shaped recess 12 and parallel to the sidewall 2 forms an axis of rotation R for a rotational relative movement, more specifically a pivot axis for a pivotal relative movement between the intervertebral implant 1 and the insertion device 100.

[0020] The sidewall 2 has in the region of the elongate opening 11 outer surfaces that are shaped so as to provide abutment surfaces for the insertion device to achieve a form-fit engagement and/or to provide guiding surfaces for a pivotal movement of the insertion device. As can be seen more in detail in Fig. 11a, the sidewall 2 protrudes in the region of the recess 10 outward in an substantially polygonal contour due to the presence of the abutment surfaces.

[0021] Referring in particular to Figs. 2, 3 and 11a, a first abutment surface 21 is provided around the lateral edge of the elongate opening 11 that extends into the right sidewall 2c. The first abutment surface 21 is substantially planar and is configured to provide a form-fit engagement with the insertion device in an orientation of 0° between a central longitudinal axis L of the insertion device (see Figs. 4 to 8) and the central longitudinal axis LI of the intervertebral implant. A second abutment surface 22 is provided around the opposite lateral edge of the elongate opening 11 that extends into the front wall 2a. The second abutment surface 22 is substantially planar and is configured to provide a form-fit engagement with the insertion device in an orientation of 90° of the central longitudinal axis L of the insertion device and the central longitudinal axis LI of the intervertebral implant 1. A third abutment surface 23 extends around substantially a center of the opening 11 and forms an angle of 45° with the first abutment surface 21 and the second abutment surface 22. Hence, the third abutment surface 23 is configured to provide a form-fit engagement with the insertion device in an orientation of 45° of the central longitudinal axis L of the insertion device and the central longitudinal axis LI of the intervertebral implant 1.

[0022] The sidewall 2 further comprises a first guiding surface 24 that is provided between the first abutment surface 21 and the third abutment surface 23 and that is cylindrical with the cylinder axis being coaxial with the rotational axis R. A second guiding surface 25 is provided between the second abutment surface 22 and the third abutment surface 23 which is also cylindrical having a cylinder axis that is coaxial with the rotational axis R. The first and second guiding surfaces 24, 25 allow a guided rotational, more particular a pivotal movement between the intervertebral implant 1 and the insertion device 100 when the insertion device is connected and slightly frictionally clamped to the intervertebral implant 1.

[0023] Optionally the intervertebral implant 1 comprises further receiving portions, for example recesses in the sidewall 2 for connection with the insertion device 100 to permit the placement of the intervertebral implant with the insertion device in various surgical approaches. In the embodiment shown, the intervertebral implant comprises an additional recess 30 at substantially the center of the front wall 2a and an additional recess 30' at the left sidewall 2b.

[0024] The recesses 30, 30' each have an overall inner cross-section that corresponds to a circle with cut away opposite sides so as to provide an elongate opening 31 with flat upper and lower edges that are parallel to the upper and lower edges of the sidewall 2. The size of the recesses 30, 30' is such that the engagement portion of the drive shaft can be inserted in one orientation only and cannot be inserted in a tilted orientation. As shown more in detail, for example, in Figs. 11a to 11c, each recess 30, 30' comprises an inner spherically-shaped recess 32, the radius of which matches the radius of the engagement portion of the drive shaft so that the engagement portion can be rotated inside to assume a 90° tilted orientation.

[0025] Turning now to Figs. 1 to 8, the insertion device 100 will be described. The insertion device 100 includes a drive shaft 110, a guiding sleeve 120 receiving the drive shaft 110 therein, a handle 130 and a rotation actuating button 135 and an axial position adjusting device 140. The drive shaft 110 is movably guided within the guiding sleeve 120 and may be advanced or retracted with respect to the guiding sleeve 120 by actuating the axial position adjusting device 140. Further, the drive shaft 110 may be rotated by actuating the rotation actuating button 135.

[0026] It shall be noted that an axial displacement of the drive shaft and rotation of the drive shaft may be achieved in various ways.

[0027] The drive shaft 110 defines a longitudinal axis L of the insertion device. It has a front portion which is shown more in detail in Figs. 4 to 6. The front portion comprises an engagement portion 111 having a partially spherical shape with a spherical surface 112 that has the shape of a segment of a sphere. The spherical surface 112 may be obtained by removing opposite segments of the sphere to yield opposite flat surfaces 113. Hence, the engagement portion 111 has a flattened shape with a thickness between the flat surfaces 113 that is slightly smaller than the width of the elongate opening 11 and the width of the openings 31 of the optional recesses 30, 30' in the height direction of the intervertebral implant 1. This permits to insert the engagement portion 111 into the recess 10 and optionally into the recesses 30, 30' of the intervertebral implant 1 in an orientation where the flat surfaces 113 extend perpendicular to the height direction of the sidewall 2.

[0028] On at least one, preferably on both of the flat surfaces 113, a longitudinally extending positioning mark 114 is provided, that extends parallel to the central longitudinal axis L of the insertion device.

[0029] The engagement portion 111 is connected to a main portion 115 via a neck portion 116. The neck portion 116 has an outer diameter that is smaller than the maximum diameter of the spherical surface portion 112 of the engagement portion 111. The main portion 115 may have a greater diameter than the neck portion 116. The spherical segment-shaped portion 112 of the engagement portion 111 has such a size that, once it has been inserted into the recess 10 and engages the spherical recess 12 or optionally into the recesses 30, 30' and engages the spherical recesses 32, respectively, of the intervertebral implant 1, it can be tilted by 90° so that the engagement portion 111 can pivot in the spherical recess 12 or optionally in the spherical recesses 32.

[0030] The front portion of the guiding sleeve 120 is shown more in detail in Figs. 7 to 9. When the drive shaft 110 is arranged in the guiding sleeve 120, the engagement portion 111 protrudes out of the front portion of the guiding sleeve 120. Two opposite cylindrical projections 122 form the outermost end of the guiding sleeve 120. The cylindrical projections 122 have a size such that they may penetrate into the recesses 10, 30, 30', respectively. An end face of the tubular guiding sleeve 120 comprises a planar surface 123 and a concave, more in detail, a cylindrical surface 124 that is arranged between the two projections 122 and the cylinder axis of which is perpendicular to the central longitudinal axis L. The planar surface 123 thus forms adjacent each projection 122 a planar surface portion that forms an abutment surface for abutting against the first or the second or the third abutment surfaces at the sidewall 2 of the intervertebral implant 1 when the guiding sleeve 120 is pressed against the sidewall 2. The cylindrical surface 124 forms a guiding surface that is configured to cooperate with the first or the second guiding surface 24, 25 at the sidewall 2 of the intervertebral implant to permit a guided rotational movement of the intervertebral implant relative to the insertion device. Hence, a radius of the cylindrical guiding surface 124 corresponds to a radius of the cylindrical guiding surfaces 24, 25 on the sidewall of the intervertebral implant 1.

[0031] At an outer wall of the guiding sleeve 120 adjacent to the cylindrical projections 122 in a longitudinal direction, two opposite positioning flats 125 may be provided. The positioning flats 125 indicate the position of the cylindrical projections 122 and may serve for orienting the insertion device correctly during connection with the intervertebral implant. Moreover, at least one longitudinally extending positioning mark 126 at the outside of the front portion of the guiding sleeve 120 may be provided that is 90° offset from the positioning flats 125 and indicates the position of the cylindrical guiding surface 124.

[0032] When the drive shaft 110 is inserted into the guiding sleeve 120 and the engagement portion 111 projects out of the front portion of the guiding sleeve 120, the drive shaft 110 may be pushed forward and retracted by actuating the axial position adjustment device 140. The size of the projections 122 is such that the engagement portion 111 can only be retracted between the projections 122 in the 90° upright position of the engagement portion 111.

[0033] The intervertebral implant 1 may for example, be made of titanium or stainless steel or of any bio-compatible metal or metal alloy or plastic material. As bio-compatible alloy a NiTi alloy, for example Nitinol, may be used. Other materials can be magnesium or magnesium alloys. Bio-compatible plastic materials for use may be, for example, polyether ether ketone (PEEK) or poly-L-lactide acid (PLLA). Also the insertion device may be made of the same material as the intervertebral implant or of another material.

[0034] Next, the operation of the intervertebral implant 1 and the insertion device will be explained. First, steps of connecting the insertion device 100 to the intervertebral implant 1 will be explained referring to Figs. 10a to 11d. As shown in Fig. 10a and 11a, the engagement portion 111 of the drive shaft 110 protrudes out of the front portion of the guiding sleeve 120. The engagement portion 111 is oriented relative to the intervertebral implant in such a manner that the flat surfaces 113 are parallel to the upper and lower edges of the elongate opening 11. The correct orientation can be easily found with the aid of the positioning mark 114 that is aligned with the position mark 126 on the guiding sleeve 120. As further depicted in Figs. 10b and 11b, the engagement portion 111 is inserted into the recess 10 through the elongate opening 11 until the spherical surface portion 112 abuts against the corner of the recess 10. The cylindrical projections 122 of the guiding sleeve 120 enter into the recess 10 so that the sidewall 2 can abut against the abutment surface 123 of the front portion of the guiding sleeve 120. In the insertion position shown in Figs. 10b and 11b, the third abutment surface 23 of the intervertebral implant comes in contact with the abutment surface 123 of the guiding sleeve 120. Hence, the longitudinal axis L of the insertion device forms an angle of 45° with the central longitudinal axis LI of the intervertebral implant 1.

[0035] Next, as explained in Figs. 10c and 11c, the drive shaft 110 is rotated, more specifically tilted, in the spherical recess 12 in the intervertebral implant 1 such that the flat surfaces 113 extend perpendicular to the longitudinal axis L of the insertion device. In this orientation, the spherical portion 112 of the engagement portion can pivot in the spherical recess 12 of the intervertebral implant 1. This rotation by 90° may be effected by actuating the button 135 at the handle.

[0036] Finally, as indicated by the straight arrow in Fig. 11d, the drive shaft 110 is pulled backwards. Thereby it can move between the cylindrical projections 122 which can enter into the recess 10. When the engagement portion 111 is oriented vertically in the recess 10 and in the spherical recess 12, i.e. the flat surfaces 113 extend parallel to the axis of rotation, the engagement portion 111 cannot be removed from the recess 10 through the opening 11. Also, if the engagement portion 111 is oriented vertically in the recesses 30, 30', the engagement portion cannot be removed through the openings 31, respectively. At the same time the abutment surface 23 of the intervertebral implant and the abutment surface 123 of the guiding sleeve 120 are pressed against each other when the insertion device is tightened against the intervertebral implant. Due to the flat abutting surfaces, a form-fit connection is provided so that rotation, more in detail pivoting of the intervertebral implant relative to the insertion device is prevented. By final tightening of the insertion device relative to the intervertebral implant the connection is locked.

[0037] Figs. 12 to 19 show the different orientations that the insertion device can assume with respect to the intervertebral implant 1. In Fig. 12, the third abutment surface 23 cooperates with the planar abutment surface 123 provided on the guiding sleeve 120. Hence, the insertion device and the intervertebral implant form an angle of 45°. In Figs. 13 and 16 the intervertebral implant abuts with the second abutment surface 22 against the corresponding abutment surface 123 at the guiding sleeve 120. Hence, the insertion device and the intervertebral implant form an angle of 90°. In Figs. 14 and 17 the intervertebral implant abuts with the first abutment surface 21 against the corresponding abutment surface 123 at the guiding sleeve 120. Hence, the insertion device and the intervertebral implant form an angle of 0°. In Figs. 15 and 18, the intervertebral implant abuts with its cylindrical guiding surface 124 against the cylindrical guiding surface 24 at the insertion device. As the surfaces permit to pivot the implant against the insertion device, there is a frictional engagement which allows to assume various angular positions of the insertion device relative to the implant. Each position can be fixed by retracting the drive shaft 110 so that the engaging surfaces are pressed against each other. Thereby, the connection is fixed by frictional clamping.

[0038] Figs. 19 and 20 show the engagement of the intervertebral implant through the additional recess 30 in the front wall 2a. Figs. 21 and 22 show the engagement of the intervertebral implant through the additional recess 30' in the in the left side wall 2d. The implant and the insertion device can be locked together in a single position.

[0039] Generally, in use, when the engagement portion 111 is in the 90° tilted upright position, it is freely pivotable around the rotational axis R, so that a plurality of angular positions of the insertion device relative to the interval implant can be adjusted. When the drive shaft 110 is retracted with the engagement portion 111 being in the upright position, the engagement portion presses from inside against a wall of the recess 10 so that the insertion device and the implant are pulled together. Thereby, various angular positions can be fixed. With the abutment surfaces, predefined angular positions, such as 0°, 90° or 45° as shown in the exemplary embodiment, can be fixed in a form-fit manner. Intermediate angular positions may be achieved by the aid of the guiding surfaces and a force-fit connection. Loosening the fixation allows to correct the relative position of intervertebral implant and the insertion device without disconneting the insertion device from the implant. This may be particularly useful for a lateral or anterior approach to the intervertebral space. The insertion device can be disconnected from the intervertebral implant by tilting the engagement portion 111 by 90° and removing it through the opening 11.

[0040] By means of the afore-mentioned steps, various access paths to the intervertebral space can be realized. Only by way of example, in a surgical TLIF method a small incision is made near the center of the back of a patient. Access is made to the damaged disk, the disk is removed and the intervertebral implant filled with bone graft is inserted. The spinal segment is then stabilized, for example using pedicle screw and rods. The intervertebral implant and the insertion device described above open a plurality of possibilities to engage the intervertebral implant and insert it into the intervertebral space. Once the intervertebral implant is finally placed in the intervertebral space, the drive shaft is pushed forward again, tilted by 90° and removed from the recess 10 or the recesses 30, 30', respectively.

[0041] Turning now to Figs. 23 to 25 a modified embodiment of the intervertebral implant is shown. The intervertebral implant 1000 is an ALIF intervertebral implant that has a slightly modified inner structure concerning the solid body 3' and the top face 5a and the bottom face 5b. In addition, holes 1001 for screws 400 are provided that are configured to engage the adjacent upper and lower vertebral bodies, respectively. The intervertebral implant 1000 also comprises the recess 10 with the elongate opening 11 as in the previous embodiment. The recess 10 may be provided at another side of the sidewall 2. An additional recess 300 in the middle of the front wall 2a forms a receiving portion for the insertion device. The recess 300 is rotated by 90° compared to the recess 30 of the previous embodiment. More in detail, the additional recess 300 extends with the opposite long sides in the height direction of the sidewall 2. By means of this, the necessary space for the recess 300 in the lateral direction can be reduced. This allows to provide the additional holes 1001 for the screws 400 to the left and to the right of the additional recess 300 on the back wall 2b.

[0042] Various modifications of the implant and/or the insertion device may be made without departing from the scope of the invention as defined in the appended claims.

[0043] For example, the intervertebral implant shown in the above-described embodiments is only an example. The contour and shape of the intervertebral implant may be different according to the specific clinical requirements. For example, the contour may have any other shape, such as circular, rectangular, oval, kidney shaped, etc. In some embodiments, the height of the sidewall may be constant throughout the implant. The intervertebral implant may also be in the form of a three-dimensional network or grid structure, that can be manufactured, for example, by 3D printing techniques. In a further modified embodiment, the intervertebral implant may be a dummy implant or testing implant that is used for a trial procedure.

[0044] The number and/or orientation and or sequence of the abutment surfaces for generating a form-fit connection between the implant and the insertion device and the number and position of the guiding surfaces is not limited to those shown in the embodiment. Various other abutment surfaces may be provided for allowing the connection of the intervertebral implant and the insertion device at various other angles. The guiding surfaces may also be omitted.

[0045] The elongate opening can be at another position. Still further, the elongate opening may extend vertically or in an inclined posture. More than one elongate opening with a recess for pivoting the implant relative to the insertion device may be provided. Also, the number of additional recesses for receiving the insertion device can be more or less than shown in the described embodiments.


Claims

1. An intervertebral implant including
a body configured to be inserted into an intervertebral space,
a hollow space (10) provided in the body and configured to accommodate an engagement portion (111) of a drive shaft (110) of an insertion device (100) therein and being accessible from outside the body through an opening (11),
wherein the opening (11) is elongate so as to permit the intervertebral implant and the insertion device to pivot relative to each other around an axis of rotation (R) at least from a first angular position to a second angular position when the engagement portion (111) is within the hollow space (10),
and wherein the intervertebral implant further comprises at least a first abutment surface (21) and a second abutment surface (22) each configured to engage an abutment surface (123) formed at the insertion device (100) to provide a form-fit connection between the intervertebral implant (1, 1000) and the insertion device (100) when the insertion device (100) is tightened against the intervertebral implant in the first angular position or in the second angular position.
 
2. The intervertebral implant of claim 1, wherein the hollow space (10) comprises a spherical portion (11) and wherein the engagement portion has a spherical portion (112) having a radius of the sphere matching that of the spherical portion (12) of the hollow space (10).
 
3. The intervertebral implant of claim 2, wherein the axis of rotation (R) is defined by an axis extending through the center point of the spherical portion (12) of the hollow space (10) and being substantially parallel a plane defined by the edge of the elongate opening (11).
 
4. The intervertebral implant of one of claims 1 to 3, wherein the body comprises a solid portion (3) and wherein the hollow space (10) is formed by a recess in the solid portion (3) of the body.
 
5. The intervertebral implant of one of claims 1 to 4, wherein the first abutment surface (21) and the second abutment surface (22) at the intervertebral implant (1, 1000) comprises a planar surface and wherein preferably the corresponding abutment surface (123) at the insertion device (100) comprises a planar surface.
 
6. The intervertebral implant of one of claims 1 to 5, wherein the first abutment surface (21) is provided at an outer surface of the body preferably in a region adjacent to the elongate opening (11).
 
7. The intervertebral implant of one of claims 1 to 6, wherein the second abutment surface (22) is provided at an outer surface of the body, preferably in a region adjacent to the elongate opening (11).
 
8. The intervertebral implant of one of claims 1 to 7, wherein the first abutment surface (21) and the second abutment surface (22) are provided at a location that corresponds to the first and the second angular positions, respectively, and wherein preferably the first and the second angular positions are about 90° rotated relative to each other.
 
9. The intervertebral implant of one of claims 1 to 8, further comprising at least a third abutment surface (23), preferably formed at an outside of the body adjacent to the elongate opening (11), configured to engage the corresponding abutment surface (123) at the insertion device to provide a form-fit connection between the intervertebral implant (1, 1000) and the insertion device (100) when the insertion device (100) is tightened against the intervertebral implant.
 
10. The intervertebral implant of claim 9, wherein the third abutment surface (23) is located between the first abutment surface (21) and the second abutment surface (22) and corresponds preferably to an intermediate angular position between 0° and 90°.
 
11. The intervertebral implant of one of claims 1 to 10, further comprising a guiding surface (24, 25) configured to cooperate with a corresponding guiding surface (124) on the insertion device (100) to achieve a plurality of angular positions in an angular range when the intervertebral implant is moved relative to the insertion device and for providing a force-fit connection at a specific angular position between the intervertebral implant (1, 1000) and the insertion device (100) when the insertion device (100) is tightened against the intervertebral implant.
 
12. The intervertebral implant of claim 11, wherein the guiding surface (24, 25) at the intervertebral implant and the corresponding guiding surface (124) at the insertion device are cylindrical.
 
13. The intervertebral implant of one of claims 1 to 12, wherein the body comprises two opposite long sides (2a, 2b) and two opposite short sides (2c, 2d) between the long sides, respectively, the short sides being shorter than the long sides, and wherein the elongate opening (11) is provided at a transition of one long side (2b) to the adjacent short side (2c).
 
14. The intervertebral implant of one of claims 1 to 13, further comprising at least one further opening (30, 30') at a position different from the elongate opening (11) and configured to accommodate the engagement portion (111) in a single angular position of the intervertebral implant (1, 1000) relative to the insertion device (100).
 
15. A system comprising an intervertebral implant according to one of claims 1 to 14 and an insertion device, the insertion device including

a drive shaft (110) provided with the engagement portion (111) at an end thereof,

a guiding sleeve (120) movably holding and guiding the drive shaft (110) and comprising the corresponding abutment surface (123) and optionally the guiding surface (124), preferably at a free end of the sleeve; and

wherein preferably the engagement portion (111) can assume a first configuration within the hollow space (10) in which it can pivot and a second configuration in which it is tightened against the intervertebral implant.


 




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Cited references

REFERENCES CITED IN THE DESCRIPTION



This list of references cited by the applicant is for the reader's convenience only. It does not form part of the European patent document. Even though great care has been taken in compiling the references, errors or omissions cannot be excluded and the EPO disclaims all liability in this regard.

Patent documents cited in the description