INTERVERTEBRAL IMPLANT AND INSERTION DEVICE THEREFOR
20250302638 ยท 2025-10-02
Inventors
Cpc classification
A61F2002/4627
HUMAN NECESSITIES
A61F2002/30092
HUMAN NECESSITIES
A61F2/447
HUMAN NECESSITIES
A61F2002/4628
HUMAN NECESSITIES
A61F2/4455
HUMAN NECESSITIES
A61F2002/3054
HUMAN NECESSITIES
A61F2/4465
HUMAN NECESSITIES
A61F2002/30795
HUMAN NECESSITIES
International classification
Abstract
An intervertebral implant includes a body with a first face, a second face connected to the first face, and an axis of rotation. The body defines a hollow space for connecting to an insertion device, the hollow space being accessible through an opening formed between the first and second faces. The opening is elongate and extends around the axis of rotation to facilitate pivoting of the implant relative to the insertion device about the axis of rotation to a first angular position and a second angular position. The implant further includes a first abutment surface that engages the insertion device in a form-fit manner at the first angular position, and a second abutment surface that engages the insertion device in a form-fit manner at the second angular position. The opening can also engage the insertion device to hold the implant at least one additional angular position.
Claims
1. An intervertebral implant comprising: a body insertable into an intervertebral space, the body comprising a first face, a second face connected to and opposite the first face, and an axis of rotation extending from the first face to the second face, wherein the body defines a spherical segment-shaped hollow space between the first and second faces configured to accommodate an engagement portion of an insertion device, the hollow space being accessible from outside the body through an opening formed between the first and second faces; wherein when viewed in a cross-section perpendicular to the axis of rotation, the intervertebral implant has an outer profile defining the opening that has a first abutment surface with a flat contour for engaging the insertion device in a form-fit manner at a first angular position and a second abutment surface with a flat contour for engaging the insertion device in a form-fit manner at a different second angular position when the engagement portion of the insertion device is in the hollow space.
2. The intervertebral implant of claim 1, wherein the axis of rotation extends through a center of the hollow space, such that the insertion device is pivotable relative to the insertion device around the axis of rotation at least between the first and second angular positions when the engagement portion of the insertion device is in the hollow space.
3. The intervertebral implant of claim 1, wherein the axis of rotation is substantially parallel to a sidewall that extends between the first and second faces.
4. The intervertebral implant of claim 1, wherein when viewed in the cross-section perpendicular to the axis of rotation, the outer profile defining the opening of the intervertebral implant further has a curved contour that extends circumferentially around the axis of rotation between the first and second abutment surfaces.
5. The intervertebral implant of claim 1, wherein the first and second angular positions are arranged at about 90 relative to each other.
6. The intervertebral implant of claim 1, wherein a sidewall that extends between the first and second faces comprises two opposite long sides and two opposite short sides extending between the long sides, and wherein the opening extends from one of the long sides to one of the short sides.
7. The intervertebral implant of claim 1, wherein the intervertebral implant is monolithic.
8. An intervertebral implant comprising: a body insertable into an intervertebral space, the body comprising a first face, a second face connected to and opposite the first face, and an axis of rotation extending from the first face to the second face, wherein the body defines a first hollow space that is accessible through a first opening formed between the first and second faces and a second hollow space that is accessible through a second opening formed between the first and second faces, wherein the first and second hollow spaces are shaped similarly to interchangeably accommodate an engagement portion of an insertion device; wherein the first opening extends circumferentially around the axis of rotation from a first end to a second end that is angled relative to the first end to facilitate circumferential pivoting of the intervertebral implant relative to the insertion device around the axis of rotation when the engagement portion of the insertion device is in the first hollow space, and wherein the second opening extends circumferentially from a first end to a second end that is substantially parallel to the first end to restrict circumferential pivoting of the intervertebral implant relative to the insertion device when the engagement portion of the insertion device is in the second hollow space.
9. The intervertebral implant of claim 8, wherein a width of the first opening measured circumferentially around the axis of rotation is greater than a height of the first opening measured in a direction parallel to the axis of rotation, and wherein a height of the second opening measured in the direction parallel to the axis of rotation is at least a width of the second opening measured circumferentially around the axis of rotation.
10. The intervertebral implant of claim 9, wherein the height of the second opening is greater than the width of the second opening.
11. The intervertebral implant of claim 8, wherein when viewed in a cross-section perpendicular to the axis of rotation, at least part of an outer profile defining the first opening has a curved contour that extends circumferentially around the axis of rotation to facilitate the pivoting of the intervertebral implant relative to the insertion device.
12. The intervertebral implant of claim 8, wherein when viewed in a cross-section perpendicular to the axis of rotation, at least part of an outer profile defining the first opening has a flat contour for engaging the insertion device in a form-fit manner at a first angular position.
13. The intervertebral implant of claim 8, wherein a sidewall that extends between the first and second faces comprises two opposite long sides and two opposite short sides extending between the long sides, and wherein the first opening extends from a first one of the long sides to a first one of the short sides.
14. The intervertebral implant of claim 13, wherein the second opening is formed entirely in one of the long sides or one of the short sides.
15. The intervertebral implant of claim 8, wherein the second opening is configured to connect the intervertebral implant to the insertion device at a fixed angular position.
16. The intervertebral implant of claim 8, wherein the intervertebral implant is monolithic.
17. An intervertebral implant comprising: a body insertable into an intervertebral space, the body comprising a first face, a second face connected to and opposite the first face, and an axis of rotation extending from the first face to the second face, wherein the body defines a hollow space between the first and second faces configured to accommodate an engagement portion of an insertion device, the hollow space being accessible from outside the body through an opening formed between the first and second faces; wherein when viewed in a cross-section perpendicular to the axis of rotation, the intervertebral implant has an outer profile defining the opening that has three distinct abutment surfaces each having a flat contour for respectively engaging the insertion device in a form-fit manner at three different angular positions and a separate curved contour that extends circumferentially around the axis of rotation to facilitate pivoting of the intervertebral implant relative to the insertion device when the engagement portion of the insertion device is in the hollow space.
18. The intervertebral implant of claim 17, wherein two of the three distinct abutment surfaces are arranged at about 90 relative to each other.
19. The intervertebral implant of claim 18, wherein a third distinct abutment surface of the three distinct abutment surfaces is arranged between and separates the two of the three distinct abutment surfaces.
20. The intervertebral implant of claim 17, wherein a first one of the three distinct abutment surfaces extends past a first end of the opening in a first circumferential direction around the axis of rotation, while a second one of the three distinct abutment surfaces extends past an opposite second end of the opening in a circumferential direction around the axis of rotation opposite the first circumferential direction.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] Further features and advantages will become apparent from the detailed description of embodiment by means of the accompanying drawings. In the drawings:
[0014]
[0015]
[0016]
[0017]
[0018]
[0019]
[0020]
[0021]
[0022]
[0023]
[0024]
[0025]
[0026]
[0027]
[0028]
[0029]
[0030]
[0031]
[0032]
[0033]
[0034]
[0035]
[0036]
[0037]
[0038]
DETAILED DESCRIPTION
[0039]
[0040] In greater detail, the sidewall 2 is formed by 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 sidewalls 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 shown, 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
[0041] 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 penetration into the end plates of adjacent vertebral bodies. The front wall 2a and the back wall 2b may have different heights, such that the top face 5a and the bottom face 5b form an angle, resulting in the intervertebral implant 1 having a wedge shape.
[0042] As can be seen in detail in particular in
[0043] A width of the recess 10 in the height direction 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 a size such that a drive shaft of the insertion device can assume an angle as small as about 020 and an angle as large as about 90 with the central longitudinal axis LI of the intervertebral implant 1.
[0044] 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 is sized to permit 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, and more specifically a pivot axis for pivotal movement between the intervertebral implant 1 and the insertion device 100.
[0045] The sidewall 2 has, in the region of the elongate opening 11, outer surfaces that are shaped to provide abutment surfaces for the insertion device to achieve a form-fit engagement and/or to provide guiding surfaces for pivotal movement of the insertion device. As can be seen in greater detail in
[0046] Referring in particular to
[0047] The sidewall 2 further includes 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 a 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, and is also cylindrical with a cylinder axis that is coaxial with the rotational axis R. The first and second guiding surfaces 24, 25 allow a guided rotational, and more particularly a pivotal, movement between the intervertebral implant 1 and the insertion device 100 when the insertion device is connected and, for example, slightly frictionally clamped to the intervertebral implant 1.
[0048] Optionally the intervertebral implant 1 may include 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 using various other surgical approaches. In the embodiment shown, the intervertebral implant has an additional recess 30 at substantially the center of the front wall 2a and an additional recess 30 at the left sidewall 2d.
[0049] 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, but cannot be inserted in a tilted orientation. As shown in greater detail, for example, in
[0050] Turning now to
[0051] The drive shaft 110 defines a longitudinal axis L of the insertion device, and has a front portion which is shown in greater detail in
[0052] On at least one, and 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.
[0053] 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 a size such that, once portion 112 has been inserted into the recess 10 and engages the spherical recess 12 or into one of the recesses 30, 30 and engages a spherical recess 32, portion 112 can be tilted by 90 so that the engagement portion 111 is held in but can still pivot in the spherical recess 12 or in one of the spherical recesses 32.
[0054] The front portion of the guiding sleeve 120 is shown in greater detail in
[0055] At an outer wall of the guiding sleeve 120 adjacent to the cylindrical projections 122 in a longitudinal direction, two opposite positioning flat surfaces 125 may be provided. The positioning flat surfaces 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 an outside of the front portion of the guiding sleeve 120 may further be provided that is 90 offset from the positioning flat surfaces 125 and that indicates the position of the cylindrical guiding surface 124.
[0056] 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 a 90 upright position of the engagement portion 111.
[0057] 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. With respect to bio-compatible alloys, a NiTi alloy, for example Nitinol, may be used. Other materials that can be used are, for example, magnesium or magnesium alloys. Bio-compatible plastic materials that can be used 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.
[0058] 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, with reference to
[0059] Next, as explained in
[0060] Finally, as indicated by the straight arrow in
[0061]
[0062]
[0063] Generally, in use, when the engagement portion 111 is in the 90 tilted upright position, the engagement portion 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 and achieved. 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 also be achieved by the aid of the guiding surfaces and a force-fit connection. Loosening the fixation allows adjustments to the relative position between intervertebral implant and the insertion device without disconnecting 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 or detaching the engagement portion through the opening 11.
[0064] By means of the aforementioned steps, various access paths to an 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 according to embodiments of the invention open a variety of possibilities to engage the intervertebral implant and to insert the intervertebral implant into the intervertebral space. Once the intervertebral implant is finally implanted in the intervertebral space, the drive shaft is pushed forward again, tilted by 90 , and removed from the recess 10 or one of the recesses 30, 30, respectively.
[0065] Turning now to
[0066] Various other modifications of the implant and/or the insertion device may further be made without departing from the scope of the invention.
[0067] 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 specific clinical requirements. For example, the contour may have any other shape, such as circular, rectangular, oval, kidney shaped, among others. 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.
[0068] The number, 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/or position of the guiding surfaces is not limited to those shown in the disclosed embodiments. Various other abutment surfaces may be provided for adjusting the connection between the intervertebral implant and the insertion device at various other angles. The guiding surfaces may also be omitted.
[0069] In some embodiments, the elongate opening can be at another position. Still further, the elongate opening may extend vertically or at an incline. In some embodiments, more than one elongate opening with a recess for pivoting the implant relative to the insertion device may be provided. Also, a number of additional recesses for receiving the insertion device can be more or less than that shown in the described embodiments.
[0070] While the present invention has been described in connection with certain exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but is instead intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims, and equivalents thereof.