Patent Description:
In the case of damaged intervertebral discs, 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 as well as oblique lateral interbody fusion.

An intervertebral implant and a device for inserting the same that are, for example, suitable for TLIF are described in <CIT>. 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.

<CIT> describes a spacer with temporary fixation which includes the spacer, a plate, an attachment member and a temporary fixation screw. The temporary fixation of the spacer is applicable in a lateral spinal procedure to prevent migration of the spacer while a patient is being rotated after insertion of the spacer.

<CIT> discloses an insertion tool and methods for inserting and/or placing an implant in a patient, whereby the implant comprises at least one connection portion, for instance an elongated opening, for connecting the engagement portion of a holding tool according to a first orientation and preventing the tool from being removed when said engagement portion is in a second orientation. The insertion device may be removed from the implant once positioned, or may be reconnected at another location to further position the implant.

It is an object underlying the invention to provide an improved or alternative implant, an insertion device therefor, and a fixation device, and systems including the implant and an insertion device or a fixation device such as a plate assembly that are versatile and simple in use and have an enlarged field of application.

The object is solved by an implant according to claim <NUM>, by an insertion device according to claim <NUM>, by a plate assembly according to claim <NUM> and by systems according to claims <NUM> or <NUM>. Further developments are given in the dependent claims. The further developments as described in the dependent claims of a particular independent claim are also applicable to the other independent claims, even if not explicitly stated.

According to an embodiment in implant, in particular a spinal implant, for example an intervertebral implant or a placeholder for vertebrae includes a body insertable into the space between two bones or bone parts, more particularly between two vertebrae, the body comprising a first face, a second face connected to and opposite to the first face, wherein the body comprises at least one connection portion for connecting the spinal implant to a holding member of an insertion device for the implant or of a secondary device such as a plate member. The connection portion comprises a hollow space defined by the body between the first and second faces configured to accommodate an engagement portion of the holding member, the hollow space being accessible from outside the body through an opening formed between the first and second faces. The opening is elongate with a length that is greater than a width in at least a portion thereof such that the engagement portion of the holding member is insertable into the hollow space through the opening when the engagement portion has a first orientation and is prevented from removal from the hollow space when the engagement portion is in a second orientation; and wherein the connection portion is located on the implant and configured in such a way that it permits to selectively connect at least two different holding to the implant.

The connection portion of the implant, in particular the spinal implant is multi-functional. It is designed such that a holding portion of a further device, such as an insertion instrument or a plate member, which is adapted to cooperate with the connection portion can be inserted and tilted whereafter it is prevented from removal. In addition, other instruments, such as a different insertion device which is suitable for a different surgical insertion approach, may be connected to the implant using the connection portion in a different manner.

The connection is threadless which renders it robust and easy to establish, disconnect and reconnect.

The implant, in particular the spinal implant may be an intervertebral implant for disc replacement or a placeholder for bridging the gap in case of removal of one or more vertebrae or portions thereof.

Due to the increase in functionality, the implant may be particularly useful in the case of difficult anatomical circumstances such as an anterior and lateral approaches to the spine as well as revision surgery.

According to a further embodiment, an insertion device for inserting the implant described above comprises two holding members each having an engagement portion wherein the holding members form a fork-shaped holding portion of the insertion device and wherein the engagement portions are configured to engage connection portions provided at opposite corners of the implant, respectively. The holding members are configured to move from a first configuration in which the engagement portions have a first distance from each other to a second configuration in which the engagement portions have a second distance from each other smaller than the first distance. A sleeve may be provided around the holding members which is displaceable relative to the holding members such as to move them from the first configuration to the second configuration.

With such an insertion device the implant, in particular the spinal implant, most suitable an intervertebral implant, may be engaged in a clamp like manner and fixed by the instrument. The implant may then be inserted, for example, in an anterior approach.

According to a further embodiment, a plate assembly comprises a plate member and a holding member connectable to the plate member wherein the holding member comprises an engagement portion that is configured to engage the connection portion of the spinal implant in a threadless manner. In particular, the plate member may be used as a temporary fixation plate which can provide temporary stability to the spinal region which comprises the implant.

The threadless connection may also permit the plate member to assume various angular positions relative to the implant, in particular the spinal implant.

According to a still further embodiment, the implant, in particular the spinal implant comprises a tube member with openings therein which is intended to form a placeholder for one or more removed vertebrae or portions thereof. The hollow space of the connection portion is formed inside the tube.

According to a still further embodiment, a kit of an implant, in particular a spinal implant as described above with at least two devices out of a group comprising at least two different insertion devices as described hereinafter and a plate assembly.

Further features and advantages will become apparent from the detailed description of embodiment by means of the accompanying drawings. In the drawings:.

<FIG> shows a perspective view of a spinal implant in the form of an intervertebral implant <NUM> and an insertion device <NUM> for inserting the intervertebral implant <NUM> into an intervertebral space. The intervertebral implant <NUM> shown in the Figures may be used in particular for anterior lumbar interbody fusion (ALIF). However, the embodiment is not limited to such type of intervertebral implant. Referring in addition in more detail to <FIG>, the intervertebral implant <NUM> has a body including a substantially vertical side wall <NUM>. The side wall <NUM> is formed monolithically with an inner solid portion <NUM> and encloses one or more inner hollow spaces <NUM>. The hollow spaces <NUM> are open towards an upper face 5a and a lower face 5b of the intervertebral implant <NUM>.

In greater detail, the side wall <NUM> is formed by a front wall 2a, an opposite back wall 2b, a right side wall 2c, and a left side wall 2d, which are monolithically formed, such that the right and left side walls 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 <NUM>. The front wall 2a and the back wall 2b may be longer than the right side wall 2c and the left side wall 2d, so that the intervertebral implant <NUM> may have 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. Moreover, 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 <NUM> having a wedge shape. For example, the front wall 2a may have a height greater than that of the back wall 2b for the correction of lordosis.

Optionally, inner walls 6a, 6b may extend from the front wall 2a to the back wall 2b by means of which the hollow spaces <NUM> are separated from each other. In the embodiment shown, three such hollow spaces <NUM> are provided, however, the design of the intervertebral implant is not limited to this number. The inner walls 6a, 6b may by symmetric with respect to a sagittal plane S that extends vertically through the centers of the front wall 2a and the back wall 2b. The solid portion <NUM> extends from the front wall 2a to a distance from the back wall 2b and has a length in this direction such that connection portions in the form of recesses, as further described below, can be formed in a solid body <NUM> with depths sufficient for engagement with the insertion device <NUM>. The hollow spaces <NUM> are configured to be filled with bone graft material or biologics. Further, engagement portions, for example teeth (not shown), may be provided in the upper face 5a and the lower face 5b of the intervertebral implant <NUM>, which may facilitate penetration into the end plates of adjacent vertebral bodies.

At the corners that are formed by the transition of the front wall 2a to the left side wall 2b and to the right side wall 2c, recesses <NUM>, <NUM>', respectively are provided that each form an elongate opening <NUM> in the side wall <NUM>. Each recess <NUM>, <NUM>' defines a connection portion for connection with a holding portion of an insertion device or a plate member.

The two recesses <NUM>, <NUM>' are mirror symmetrical with respect to the sagittal plane S and therefore in the following, only the recess <NUM> will be described in more detail while in the embodiment, the recess <NUM>' at the opposite corner has a mirror symmetrical design. The recess <NUM> defines a hollow space within the intervertebral implant <NUM> for receiving a portion of the insertion device. The recess <NUM> extends into the solid portion <NUM> and forms a corner with an angle of slightly more than <NUM> therein. Thereby, left and right boundary walls 10a, 10b of the recess <NUM> form an angle of slightly more than <NUM> °, for example about up to <NUM>°. The recess <NUM> and the opening <NUM> may be provided at a middle of the side wall <NUM> in the height direction. It shall be understood, that the angle may also be about or exactly <NUM>°.

A width of the recess <NUM> in the height direction is such that an engagement portion of the insertion device <NUM> can be introduced in one orientation, but cannot be introduced in a tilted orientation. Top and bottom walls of the recess <NUM> may be planar, and may extend substantially parallel to each other and substantially perpendicular to the side wall <NUM>. The opening <NUM> extends in a circumferential direction from the front wall 2a over the corner between the front wall 2a and the right side wall 2c into the right sidewall.

In the inside corner of the recess <NUM>, a spherically-shaped recess <NUM> is formed that is configured to receive an engagement portion of the insertion device <NUM>. As shown in more detail in <FIG>, a radius of the spherically-shaped recess <NUM> matches a radius of an outer surface of the engagement portion of the insertion device. An axis R extending through a center of the spherically-shaped recess <NUM> and parallel to the side wall <NUM> forms an axis of rotation and more specifically, a pivot axis that enables a pivotal movement between the intervertebral implant <NUM> and an engagement portion of an insertion device or a plate member as explained in more detail below. The boundary walls 10a, 10b that delimit the recess <NUM> at the end of the opening <NUM> in the circumferential direction may have a contour that is suitable for guiding engagement with the engagement portion. It may be, for example, substantially cylindrical. The boundary wall 10b is substantially perpendicular to the right side wall 2d and the boundary wall 10a extends at a slight angle to the front wall 2a in such a manner that an enlarged portion 10c may formed between the spherical recess <NUM> and the boundary wall 10a. By means of this, the insertion of the engagement portion of the insertion device may be facilitated.

In addition, the side wall <NUM> may have, in the region of the elongate opening <NUM>, outer surfaces that are shaped to provide abutment surfaces for an insertion device to achieve a form-fit engagement and/or to provide guiding surfaces for pivotal movement of the insertion device. As depicted more in detail in <FIG>, a first abutment surface <NUM> is provided around the lateral edge of the elongate opening that extends into the right side wall 2c. For the recess <NUM>' the first abutment surface <NUM> is in the left sidewall 2d. The first abutment surface <NUM> may be substantially cylindrical with a cylinder axis substantially parallel to the axis of rotation R. A second substantially planar abutment surface <NUM> is provided around the opposite lateral edge of the elongate opening <NUM> that extends into the front wall 2a. Lastly, a third substantially planar abutment surface <NUM> may extend around substantially a center of the opening <NUM> and forms an angle of substantially <NUM>° with the second abutment surface <NUM>.

Optionally, the intervertebral implant <NUM> may include further connection portions in the side wall <NUM>. In the embodiment shown, the intervertebral implant has additional recesses <NUM>, <NUM>' at the right side wall 2c and the left side wall 2d, respectively. Each recess <NUM>, <NUM>' defines an elongate opening <NUM> and comprises an inner spherically-shaped recess <NUM>, permitting rotation of an inserted engagement portion therein. The recesses <NUM>, <NUM>' are each configured such that an engagement portion of a holding member of an insertion device or a plate member can be inserted in one orientation, but cannot be inserted in a tilted orientation. The connection portions <NUM>, <NUM>' permit only a single angle between the implant and the holding portion of the device to be attached. It shall be noted, that the connection portions <NUM>, <NUM>' may also be designed such as to allow a variation in the angle between the insertion device and the implant.

Optionally, one or more additional holes <NUM> may be provided in the front wall 2a. The additional holes may be threaded, to receive fixation screws (not shown) for additional fixation of the intervertebral implant <NUM> with respect to the adjacent vertebral bodies. The axes of the additional holes <NUM> may be inclined with respect to the top face 5a and the bottom face 5b so that fixation screws extending therethrough are configured to engage the end plates of the vertebral bodies, respectively.

It shall be noted that the number and position of the recesses and holes is not limited to the number and position shown in the embodiment but more or less recesses and holes may be provided and the positions may vary.

Turning now to <FIG> and <FIG>, the insertion device <NUM> will be described. The insertion device <NUM> includes a holding portion <NUM>, a sleeve <NUM> configured to extend around the holding portion <NUM> and a handle <NUM> connected to the holding portion. The sleeve <NUM> defines a longitudinal axis of the insertion device <NUM>. The holding portion <NUM> comprises two holding members <NUM>, <NUM>', the front portions <NUM>, <NUM>' of which form a fork-shaped clamp configured to engage the intervertebral implant <NUM>. The holding members <NUM>, <NUM>' each comprise a longitudinal bar <NUM>, <NUM>', wherein the bars <NUM>, <NUM>' are connected at their rear end <NUM>. From the rear end <NUM> a post <NUM> with a threaded end portion <NUM> extends. The front portions <NUM>, <NUM>' each include a cross-bar <NUM>, <NUM>' extending transverse to the longitudinal axis in an outward direction. From each outer end of the cross-bar <NUM>, <NUM>' an engagement portion <NUM>, <NUM>' extends in a direction substantially parallel to the longitudinal axis L. The cross-bars <NUM>, <NUM>' may have a substantially rectangular cross-section with a height that is preferably smaller than a height of the front wall 2a. The length of the cross-bars <NUM>, <NUM>' is such that the engagement portions <NUM>, <NUM>' can be inserted into the recesses <NUM>, <NUM>'.

The engagement portions <NUM>, <NUM>' have a substantially spherical segment-shaped end portion <NUM>, <NUM>' with upper and lower surfaces that are substantially flat and parallel to each other. An axis F perpendicular to the flat surfaces is substantially perpendicular to the longitudinal axis L. The outer surface of the spherical segment-shaped portions <NUM>, <NUM>' may have a small cylindrical portion 119b. Hence, the engagement portion <NUM>, <NUM>' and in particular the spherical-segment-shaped end portion <NUM>, <NUM>' have a flattened shape with a thickness slightly smaller than a vertical height of the elongate opening <NUM> to permit insertion of the engagement portion into the recess <NUM>, <NUM>'. Between the spherical segment-shaped end portions <NUM>, <NUM>' and the cross-bar <NUM>, <NUM>' the engagement portion <NUM>, <NUM>' comprises a narrowing section 119a, 119a' to provide a hook-like shape. The enlarged portion 10c may facilitate. the engagement of the engagement portion with the recess <NUM>, <NUM>', respectively, since the spreading apart of the engagement portions required for entering the recesses may be reduced.

The holding members <NUM>, <NUM>' are separated by a slot 111a that may have a widened section 111b adjacent to the end portion <NUM>. The slot 111a renders the holding members <NUM>, <NUM>' deflectable towards each other and apart from each other in a resilient manner. An outer surface portion 111c of the holding members <NUM>, <NUM>' adjacent to the cross-bars <NUM>, <NUM>' may be tapered in a direction such that it widens towards the cross-bars <NUM>, <NUM>'. When the sleeve <NUM> moves towards the cross-bars <NUM>, <NUM>' this results in compression of the holding members <NUM>, <NUM>' towards each other which narrows the slot 111a and brings the engagement portions <NUM>, <NUM>' closer towards each other.

The sleeve <NUM> is configured to extend around the bar-shaped longitudinal portions <NUM>, <NUM>' of the holding portion. It comprises a front end 120a and a rear end with a grip section <NUM> and an inner thread (not shown), for example in the region of the grip section <NUM> that is configured to cooperate with the threaded end portion <NUM> of the holding portion <NUM>. Hence the sleeve <NUM> is configured to be moved forward and backward in the longitudinal direction by rotating it relative to the holding portion <NUM>. When the sleeve is in the retracted position, its front end 120a has a distance from the cross-bars <NUM>, <NUM>' of the holding member <NUM> such that the tapered section 111c is at least partially exposed. An inner wall 120c adjacent to the front portion 120a of the sleeve <NUM> slightly tapers outward (<FIG>). This enables sliding of the sleeve over the tapered portion 111c. Moreover, longitudinal holes <NUM> may be provided in the sleeve that may serve for saving weight and/or facilitating cleaning. In a modification, the sleeve <NUM> may be moved forward and backward by pushing it relative to the holding portion <NUM>.

The insertion device is configured to have a first configuration in which the engagement portions <NUM>, <NUM>' are spaced apart from each other at a first distance and a second configuration in which the engagement portions <NUM>, <NUM>' are spaced apart at a second distance smaller than the first distance. In the first configuration the sleeve is at the retracted position. By displacing the sleeve along the longitudinal axis L the slot 111a is narrowed so that the engagement portions <NUM>, <NUM>' are moved towards each other.

Parts and portions of the intervertebral implant and the insertion device may be made of any material, preferably, however, of a bio-compatible material, such as titanium or stainless steel or any other 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). The parts can be made of the same or of different materials from one another.

Next, the operation of the intervertebral implant <NUM> and the insertion device will be explained. As shown in <FIG>, the intervertebral implant is oriented with respect to the insertion device in such a manner that the front portion of the insertion device faces the front wall 2a of the intervertebral implant <NUM>. The sleeve <NUM> is in the retracted position in which the tapered section 111c of the holding portion <NUM> is substantially free.

<FIG> shows the connected configuration in which the engagement portions <NUM>, <NUM>' have engaged the spherical recess <NUM> inside the recesses <NUM>, <NUM>'. In this configuration, the sleeve <NUM> has been moved towards the cross-bars <NUM>, <NUM>' over at least a part or most of the tapered portion 111c so that the two engagement portions <NUM>, <NUM>' are pressed towards each other.

Referring to <FIG>, the steps of engagement of the intervertebral implant with the insertion device are shown in more detail. In <FIG>, the insertion device is moved towards the front wall 2a with the sleeve <NUM> in the retracted position. In <FIG> the outer spherical segment-shaped ends <NUM>, <NUM>' of the engagement portions <NUM>, <NUM>' move through the opening <NUM> into the recesses <NUM>, <NUM>', respectively. As they slide along the inclined boundary walls 10a the holding members <NUM>, <NUM>' are slightly spread apart. As depicted in <FIG>, the outer ends <NUM>, <NUM>' of the engagement portion. <NUM>, <NUM>' have entered the spherical recesses <NUM> and clamp the implant between them. Finally, as shown in <FIG>, the sleeve <NUM> is moved towards the cross-bars <NUM>, <NUM>'. Since it slides along the tapered portion 111c, the holding members <NUM>, <NUM>' are pressed towards each other so that the outer ends <NUM>, <NUM>' of the engagement portions <NUM>, <NUM>' are firmly pressed against the wall of the recess <NUM>. By means of this, the connection is fixed.

In the clinical use, the intervertebral implant of this type may be inserted from the anterior side. Once the intervertebral implant has been placed with the insertion device <NUM> between two vertebral bodies, the insertion device is be removed. This is effected by holding the holding portion <NUM> with the handle <NUM> and retracting the sleeve <NUM>. Thereby, the clamping of the engagement portions <NUM>, <NUM>' is loosened and the engagement portions can be disengaged from the implant.

Since the height of the front portion <NUM>, <NUM>' of the insertion device is smaller than the height of the front wall 2a of the intervertebral implant <NUM>, the visibility of the intervertebral implant during the insertion process may be improved. Also the width of the insertion device is smaller than the width of the implant which may be helpful in insertion and release of the implant.

Referring to <FIG>, the intervertebral implant <NUM> is shown together with another embodiment of an insertion device. The intervertebral implant <NUM> in the form of an ALIF-cage has an increased functionality due to the connection portions in form of the recesses <NUM>, <NUM>', <NUM>, <NUM>'. The insertion device <NUM> is an insertion device which may be usually used for implants which are inserted between the vertebrae in an antero-lateral or lateral approach and require in some cases a specific angle or a variation of that angle between the insertion device and the intervertebral implant along the insertion trajectory. <FIG> shows the insertion device <NUM> engaging one of the recesses <NUM>, <NUM>' at the corners of the intervertebral implant. <FIG> shows the insertion device <NUM> engaging one of the recesses <NUM>, <NUM>' at the left sidewall or the right sidewall of the intervertebral implant.

Referring now in addition to <FIG>, the insertion device <NUM> will be described in greater detail. The insertion device <NUM> includes a holding portion <NUM>, a guiding sleeve <NUM> that receives the holding portion <NUM> therein, a handle <NUM>, a rotation actuating member (not shown), and an axial position adjusting device <NUM>. The holding member <NUM> is movably guided within the guiding sleeve <NUM> and may be advanced or retracted with respect to the guiding sleeve <NUM> by actuating the axial position adjusting device <NUM>. Further, the holding member <NUM> may be rotated by actuating the rotation actuating member. It shall be noted that axial displacement of the holding member <NUM> and rotating of the holding <NUM> may be achieved in various other ways.

The holding member <NUM> defines the longitudinal axis L of the insertion device, and has a front portion which is shown in greater detail in <FIG>. The front portion includes an engagement portion <NUM> with a spherical surface <NUM> that has the shape of a segment of a sphere. The spherical surface <NUM> may be formed by removing opposite segments of the sphere to yield opposite flat surfaces 219a. Hence, the engagement portion <NUM> has a flattened shape with a thickness between the flat surfaces 219a that is slightly smaller than a vertical height of the elongate opening <NUM> and heights of the openings <NUM> of the optional recesses <NUM>, <NUM>'. This permits insertion of the engagement portion <NUM> into the recesses <NUM>, <NUM>' and optionally into the recesses <NUM>, <NUM>' of the intervertebral implant <NUM>, in an orientation where the flat surfaces 219a extend perpendicular to the height direction of the sidewall <NUM>.

On at least one, and preferably on both, of the flat surfaces 219a a longitudinally extending positioning mark 219b may be provided, that extends parallel to the longitudinal axis L of the insertion device <NUM>.

The engagement portion <NUM> is connected to a main portion <NUM> via a neck portion <NUM>. The neck portion <NUM> has an outer diameter that is smaller than the maximum diameter of the spherical surface portion <NUM> of the engagement portion <NUM>. The main portion <NUM> may have a greater diameter than the neck portion <NUM>. The spherical segment-shaped portion <NUM> of the engagement portion <NUM> has a size such that, once the portion <NUM> has been inserted into the recess <NUM>, <NUM>' and engages the inner spherical recess <NUM> or into one of the recesses <NUM>, <NUM>' and engages the inner spherical recess <NUM>, the holding member <NUM> can be tilted by <NUM>° so that the engagement portion <NUM> is held in the spherical recess <NUM> or in one of the spherical recesses <NUM> but can still pivot therein.

The front portion of the guiding sleeve <NUM> is shown in greater detail in <FIG>. When the holding member <NUM> is arranged in the guiding sleeve <NUM>, the engagement portion <NUM> protrudes out of the front portion of the guiding sleeve <NUM>. Two opposite cylindrical projections <NUM> form the outermost end of the guiding sleeve <NUM>. The cylindrical projections <NUM> have a size such that they are insertable to the recesses <NUM>, <NUM>', <NUM>, <NUM>', respectively. An end face of the tubular guiding sleeve <NUM> includes a planar surface <NUM> and a concave, and more specifically a cylindrical surface <NUM> that is arranged between the two projections <NUM> and that has a cylinder axis which is perpendicular to the longitudinal axis L. The planar surface <NUM> thus forms adjacent each projection <NUM> an abutment surface for abutting against the second abutment surface <NUM> or the third abutment surface <NUM> at the sidewall <NUM> of the intervertebral implant <NUM> when the guiding sleeve <NUM> is pressed against the sidewall <NUM>. The cylindrical surface <NUM> forms a small guiding surface that is configured to cooperate with guiding surface <NUM> at the sidewall <NUM> of the intervertebral implant <NUM> to permit a guided rotational movement of the intervertebral implant relative to the insertion device in an angular range. Hence, a radius of the cylindrical guiding surface <NUM> corresponds to a radius of the cylindrical guiding surface <NUM> on the left sidewall 2d of the intervertebral implant <NUM>.

At an outer wall of the guiding sleeve <NUM> adjacent to the cylindrical projections <NUM> in a longitudinal direction, two opposite positioning flat surfaces <NUM> may be provided. The positioning flat surfaces <NUM> indicate the position of the cylindrical projection <NUM>, and may serve for orienting the insertion device <NUM> correctly during the connection with the intervertebral implant <NUM>. Moreover, at least one longitudinally extending positioning mark <NUM> at an outside of the front portion of the guiding sleeve <NUM> may further be provided that is <NUM>° offset from the positioning flat surfaces <NUM> and that indicates the position of the projections <NUM>.

When the holding member <NUM> is inserted into the guiding sleeve <NUM> and the engagement portion <NUM> projects out of the front portion of the guiding sleeve <NUM>, the holding member <NUM> may be pushed forward and retracted by actuating the axial position adjustment device <NUM>. The size of the projections <NUM> is such that the engagement portion <NUM> can only be retracted between the projections <NUM> in a <NUM>° upright position of the engagement portion <NUM>.

The intervertebral implant <NUM> and the insertion device may be manufactured from the same materials as described before with respect to the combination of the intervertebral implant <NUM> and the insertion device <NUM>.

Next, the operation of the intervertebral implant <NUM> and the insertion device <NUM> will be explained referring to <FIG>. The various connection possibilities provided by the recesses <NUM>, <NUM>', <NUM>, <NUM>' increase the possibilities for surgical approaches for insertion of the intervertebral implant <NUM>. First, with reference to <FIG>, an angled connection will be described in which the intervertebral implant <NUM> and the insertion device <NUM> are connected via the recesses <NUM> or <NUM>' at the corner of the implant. This connection permits to adjust the angular position between the intervertebral implant <NUM> and the insertion device <NUM>.

As depicted in <FIG>, the intervertebral implant <NUM> and the insertion device <NUM> are oriented towards each other in such a manner that the engagement portion <NUM> faces towards the recess <NUM>' at the corner between the front wall 2a and the left sidewall 2c. The engagement portion <NUM> is oriented such that the flat top and bottom surfaces 219a are substantially perpendicular to the axis of rotation R of the intervertebral implant <NUM>. The marking 219b faces towards the upper rim of the opening <NUM> which facilitates the proper orientation of the engagement portion <NUM>. As illustrated in <FIG>, in this orientation, the engagement portion <NUM> can be inserted through the opening <NUM> into the recess <NUM>' until the engagement portion <NUM> abuts against the inner wall of the spherical recess <NUM>. Then, the engagement portion <NUM> is rotated until the flat surfaces 219a extend parallel or substantially parallel to the axis of rotation R. In this configuration, the engagement portion <NUM> is prevented from being removed through the opening <NUM>. For locking the connection, the guiding sleeve is advanced such that the cylindrical projections <NUM> extend into the recess <NUM>' through the opening <NUM>. In <FIG>, the flat abutment surfaces <NUM> of the guiding sleeve <NUM> abut against the flat abutment surface <NUM> surrounding the opening as shown for example in <FIG>, so that the angle is between the longitudinal axis L of the insertion device <NUM> and the intervertebral implant <NUM> is about <NUM>°. The holding member <NUM> is pulled backward and fixed in the pulled back position to lock the parts together. The connection may be locked by actuating a locking mechanism that holds the guiding sleeve <NUM> in this position.

<FIG> show in a cross-sectional view the relation of the intervertebral implant <NUM> and the insertion device <NUM> with respect to each other during the insertion and fixation step. Hence, <FIG> shows the proper orientation before inserting the engagement portion <NUM> into the recess <NUM>' and <FIG> corresponds to the position in which the engagement portion has been rotated by <NUM>° within the recess <NUM>. In <FIG>, the connection portion <NUM> is rotated in the spherical recess <NUM> until one of the flat surfaces 219a abuts against the boundary wall 10b of the recess <NUM>' so that the insertion device <NUM> extends away from the left sidewall 2c of the intervertebral implant. In this configuration, the insertion device and the intervertebral implant form an angle of substantially <NUM>°. In <FIG>, the engagement portion <NUM> is rotated in the spherical recess <NUM> until the other one of the flat surfaces 219a abuts against the boundary wall 10a of the recess <NUM>' such that the insertion device extends from the front wall 2a of the intervertebral implant <NUM>. In this configuration, the angle between the intervertebral implant <NUM> and the insertion device is a little more than <NUM>°, due to the inclination of the boundary wall 10a with respect to the front wall 2a.

<FIG> shows the engagement of the intervertebral implant through the additional recess <NUM>' in left sidewall 2d. In this configuration, the implant and the insertion device can be locked together in a single position.

Generally, in use, when the engagement portion <NUM> is in the <NUM>° tilted upright position, the engagement portion <NUM> is freely pivotable around the rotational axis R so that a plurality of angular positions of the insertion device <NUM> relative to the intervertebral implant can be adjusted. When the holding member <NUM> is retracted with the engagement portion <NUM> being in the upright position, engagement portion <NUM> presses from inside against a wall of the recess <NUM> or <NUM>', 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 <NUM>°, <NUM>° or <NUM>° 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 <NUM>, <NUM> and a force-fit connection. Loosening the fixation allows adjustments to the relative position between the intervertebral implant and the insertion device without disconnecting the insertion device from the implant. This may be particularly useful for lateral or anterior approaches to the intervertebral space.

By means of the aforementioned steps and with a suitable combination of the intervertebral implant and the appropriate insertion device various access paths to an intervertebral space can be realized with one single type of intervertebral implant. In particular, an ALIF intervertebral implant may in some situations be inserted from the anterior side with the insertion device <NUM> and in other situations laterally using the insertion device <NUM>.

Only by way of example, in a surgical method, access is made to the damaged disc, the disc is removed, and the intervertebral implant filled with bone graft is inserted. The spinal segment is then stabilized, for example, using pedicle screws and rods. The intervertebral implant and the insertion devices 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 insertion device is removed.

Referring to <FIG>, an embodiment of the intervertebral implant and a plate assembly will be described. The intervertebral implant <NUM> is in this embodiment the same as in the previous embodiments. The plate assembly <NUM> includes a plate member <NUM> that is connectable via a holding member <NUM>, a sleeve <NUM> and a locking member <NUM> to the intervertebral implant <NUM>. The plate assembly <NUM> further includes bone fixation members <NUM> in the form of bone screws that are configured to engage the adjacent vertebrae between which the intervertebral implant <NUM> is sandwiched. The bone fixation members <NUM> each may be secured against backing out using locking members <NUM>.

The plate member <NUM> will be described in more detail referring additionally to <FIG>. The plate member <NUM> has an elongate shape with a top surface 310a and an opposite bottom surface 310b. It shall be understood that the plate member can have any shape, however, the elongate shape is useful for an application along the spinal column. End portions 310c, 310d of the plate member may be rounded, more specifically may have a substantially cylindrical outer contour. In addition, the plate member <NUM> may have a shallow curvature along its length so that it is slightly convexly shaped in a direction away from the intervertebral implant in the connected state. At a distance from the end portions 310c, 310d two holes <NUM> are provided that serve for guiding through the fixation members <NUM>, respectively. The holes <NUM> each have ad-jacent the bottom surface 310b a threaded portion 311a that is configured to cooperate with a thread on the shank <NUM> of the fixation member <NUM>. A side recess 311b is provided at each side of the threaded portion <NUM> a that faces towards the outer ends 310c, 310d. The side recesses 311b permit to orient the shank <NUM> of the fixation members <NUM> outward in an oblique manner to enable insertion into a portion of the adjacent vertebra. Adjacent to the top surface 310a each of the holes <NUM> comprises a recess <NUM> c with a greater diameter than that of the threaded portion 311a which serves for housing a head <NUM> of the fixation member <NUM>, respectively, and for accommodating the locking member <NUM>. The recess 311c may have in at least a portion thereof an inner thread that cooperates with an outer thread of the locking member <NUM>.

Between the holes <NUM> a central hole <NUM> is provided that is located substantially at the middle of the plate member <NUM> in the longitudinal direction. In the region of the central hole <NUM>, the bottom surface 310b comprises a substantially flat portion <NUM> that may serve as an abutment for the sleeve <NUM>. Adjacent to the abutment a first unthreaded portion 312a of the central hole <NUM> is formed that is substantially cylindrical and has an inner diameter that permits a portion of the holding member <NUM> to extend therethrough. At the opposite side a substantially cylindrical threadless recess 312b forms part of the hole <NUM> which has a greater diameter than the threadless portion 312a. The threadless recess 312b serves for accommodating at least a portion of the locking member <NUM>.

The holding member <NUM> will be explained in detail referring additionally to <FIG>. The holding member <NUM> comprises an engagement portion <NUM> that is shaped substantially as a segment of a sphere, i.e. it has a spherical outer surface <NUM> and flat top and bottom surfaces 339a. The shape of the engagement portion <NUM> is highly similar to the shape of the engagement portion <NUM> of the insertion device according to <FIG>. Hence, the engagement portion <NUM> is configured to engage the recesses <NUM>, <NUM>' or <NUM>, <NUM>' in the same manner as the engagement portion of the insertion device <NUM>. A marking 339b may be provided at at least one of the flat top and bottom surfaces 339a of the engagement portion <NUM>. If the holding portion <NUM> is oriented with the marking 339b facing toward the upper rim of the opening <NUM> of the recess <NUM>, the holding portion <NUM> is in the correct orientation for insertion. The engagement portion <NUM> is connected, for example monolithically, to a rod or bar <NUM>. The bar <NUM> has a threaded end portion <NUM> opposite to the engagement portion <NUM>. Between the engagement portion <NUM> and the threaded end portion <NUM> a thread-free section <NUM> is provided on which the sleeve <NUM> is placed. Between the engagement <NUM> and the thread-free section <NUM> of the holding member <NUM> a thickened section <NUM> may be provided that has a slightly greater outer diameter than the thread-free section <NUM>. The thickened section <NUM> comprises an edge <NUM> from which two projections 335a , offset by <NUM>°, extend that are configured to enter between two projections of the sleeve <NUM>. The length of the rod portion <NUM> of the holding member <NUM> is such that when the sleeve <NUM> is mounted thereon, the threaded end portions <NUM> extends through the first unthreaded portion 312a of the central hole <NUM> of the plate member <NUM> into the recess 312b in order to be engaged by the locking member <NUM>. At the threaded end portion <NUM> of the holding member, an coaxial hole <NUM>, preferably with an internal thread, for connection an insertion device, such as a threaded rod thereto (not shown).

The locking member <NUM> is a nut-like member comprising a central threaded hole <NUM> in which the threaded end portion <NUM> of the holding member can be screwed. Around the central threaded hole <NUM> a cylindrical rim <NUM> is formed that has a size such that it fits into the recess 312b of the central hole <NUM> provided in the plate member <NUM>. In addition, a plurality of elongate circumferentially arranged pockets <NUM> are provided that extend completely through the cylindrical rim <NUM> and that serve for engagement with a drive tool. Opposite to the lower side 352a of the cylindrical rim <NUM> the nut-like member comprises a cylindrical portion <NUM> with a smaller outer diameter. The length of this portion is such that once the locking member <NUM> is in the recess 312b of the central hole <NUM>, the cylindrical portion <NUM> extends out of the top surface 310a of the plate member so that it can be detected more easily with a tool.

Referring to <FIG>, the sleeve member <NUM> will be described. The sleeve member is configured to be placed onto the thread-free portion <NUM> of the holding member <NUM>. A rear end 340a of the sleeve member <NUM> is substantially flat and is configured to abut against the flat surface portion <NUM> of the plate member <NUM>. The front portion of the sleeve member comprises two substantially cylindrical projections <NUM> that are offset by <NUM>° and configured to extend through the opening <NUM> into the recesses <NUM>, <NUM>' or <NUM>, <NUM>' of the intervertebral implant <NUM>. Between the projections <NUM> an abutment surface <NUM> is formed that is configured to cooperate with an abutment surface at the intervertebral implant, for example with the abutment surface <NUM> in the corner of the intervertebral implant. An outer contour of the sleeve <NUM> may be substantially square-shaped with rounded edges. Any other contour, for example a cylindrical shape may also be possible. The projections <NUM> of the holding member <NUM> are configured to fit in-between the projections <NUM> of the sleeve member <NUM>. It shall be noted that the sleeve and the plate member can also be monolithic.

In the assembled state, the sleeve <NUM> is mounted onto the rod-like portion <NUM>, specifically onto the threadless <NUM> of the holding member <NUM> and the threaded end portion <NUM> is guided through the central hole <NUM> of the plate member <NUM> until it projects into the recess 312b. Then the locking member <NUM> is screwed onto the threaded end portion <NUM> to connect the holding member <NUM> to the plate member <NUM>. For connecting the plate assembly to the intervertebral implant after the implant has been inserted into the intervertebral space, the engagement portion <NUM> is oriented such that the flat surfaces 319a extend substantially vertical to the axis of rotation of the spherical recess <NUM>. Once the engagement portion <NUM> has been introduced into the recess <NUM>, <NUM>' or <NUM>, <NUM>' through the openings <NUM> or <NUM>, the engagement portion <NUM> is tilted by <NUM>° so that it cannot be removed through the openings <NUM> or <NUM>. Moreover, the holding member <NUM> is moved backward so that the engagement portion <NUM> abuts against the inner wall of the recess <NUM>, <NUM>', <NUM> or <NUM>'. The projections 335a move into the space between the projections <NUM> of the sleeve member <NUM> and thus inhibit rotation of the engagement portion <NUM>. Thereafter, the locking member <NUM> is tightened with respect to the holding member <NUM> so that the sleeve <NUM> is firmly pressed with its abutment surface 340a against the flat surface <NUM> of the plate member and with the abutment surface <NUM> against the abutment surface <NUM> of the intervertebral implant, as depicted in <FIG>. For manipulating the holding member <NUM> such as insertion into the recess <NUM> and rotation, a relatively thin at least partially threaded rod may guided through the locking member <NUM> and inserted into the threaded hole <NUM> of the holding member <NUM>. Due to the threadless connection, the plate member <NUM> can be easily and quickly connected to the intervertebral implant <NUM>. In addition, various angles as in the previous embodiment can be adjusted between the holding member <NUM> and the intervertebral implant <NUM>, depending on the selection of the recess <NUM>, <NUM>', <NUM> or <NUM>'. In this way, the plate can assume various orientations with respect to the intervertebral implant which enhances the possibilities of temporary stabilization. The plate member <NUM> may be additionally fixed by the bone fixation members <NUM> which are inserted into the holes <NUM> and screwed into a portion of the vertebra. The locking member <NUM> may be used to press onto the head <NUM> of the fixation member <NUM>.

In one method of use (not claimed), the plate member <NUM> remains implanted. The plate member <NUM> can also serve for a temporary fixation and can be later removed. Once the bone fixation members <NUM> have been removed, the unlocking of the holding member <NUM> from the intervertebral implant <NUM> can be achieved easily by slightly pushing in the the engagement portion <NUM>, tilting it and withdrawing the engagement portion from the recess <NUM>, <NUM>' or <NUM>, <NUM>'.

<FIG> shows a further embodiment of an intervertebral implant together with the plate assembly <NUM>. The intervertebral implant <NUM>' in this case is an lateral cage which is elongate and has the recesses <NUM>, <NUM>' for connection with the insertion device and/or the plate only on one of the short sides of the elongate implant. For example, a single recess <NUM> may be provided at the corner of a long side to a short side of the implant and a single recess <NUM> on the short side may be provided which is used in the depicted embodiment for connection to the plate member <NUM>.

<FIG> show a further embodiment of the spinal implant in the form of a placeholder <NUM>" for a vertebra or portions thereof. The placeholder comprises a cylindrical tube with a tube axis T and with openings 1a in the wall. Prongs <NUM> may be formed at either end to engage the end plates of the vertebral bodies between which the placeholder <NUM>" shall be placed.

In the wall of the placeholder <NUM>" there is an opening <NUM> that is elongate in the circumferential direction. The inside of the tube behind the opening <NUM> provides a hollow space for receiving an engagement portion of an insertion device or of a plate assembly.

As can be seen in <FIG> and <FIG>, the placeholder <NUM>" can be used together with the insertion device <NUM> according to <FIG>. The engagement portion <NUM> is inserted in the orientation in which the flat surfaces 219a are perpendicular to the cylinder axis of the tube. After insertion, the engagement portion is tilted by <NUM>° so that it is prevented from being removed through the opening <NUM>. Then, the sleeve <NUM> is advanced to press against the outer wall of the tube and is fixed in this position. Thereafter, the placeholder <NUM>" can be inserted between two vertebrae.

<FIG> shows the connection between a plate member <NUM>' and the placeholder <NUM>". The principle of the connection is the same as described with respect to the connection between the placeholder <NUM>" and the insertion device. Depending on the clinical situation, a shorter holding member <NUM>' may be used and the plate member <NUM>' may be straight, i.e. without curvature.

Various other modifications of the spacer and/or the insertion device and/or the plate assembly may further be made without departing from the scope of the invention.

The spinal implant as shown in the above described embodiments is only an example. The contour and shape of the implant may be different according to specific clinical requirements. For example, the 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 implant may be a dummy implant or testing implant that is used for a trial procedure to open the disc space before insertion of the implant that remains in the body.

The number of connection portions on the implant provided by the recesses may differ. For example, for the first embodiment it is sufficient that only one of the recesses has the specific inner shape which allows to additionally attach the other insertion device. The other one of the recesses may be shaped to only provide an abutment for the engagement portion of the insertion device.

Claim 1:
An implant, in particular a spinal implant, more particularly an intervertebral implant or a placeholder for vertebrae or portions thereof, including
a body insertable into space between two bone parts or vertebrae, the body comprising a first face (5a), a second face (5b) connected to and opposite to the first face,
wherein the body comprises at least one connection portion (<NUM>, <NUM>', <NUM>, <NUM>') for connecting the implant (<NUM>, <NUM>', <NUM>") to a holding member (<NUM>, <NUM>, <NUM>) of an insertion device (<NUM>, <NUM>) for the implant or of a secondary device such as a plate member (<NUM>),
wherein the connection portion (<NUM>, <NUM>', <NUM>, <NUM>') comprises a hollow space defined by the body between the first and second faces configured to accommodate an engagement portion (<NUM>, <NUM>'; <NUM>; <NUM>) of the holding member, the hollow space being accessible from outside the body though an opening (<NUM>, <NUM>) formed between the first and second faces;
wherein the opening (<NUM>, <NUM>) is elongate such that the engagement portion of the holding member is insertable into the hollow space through the opening when the engagement portion has a first orientation and is prevented from removal from the hollow space when the engagement portion is in a second orientation; and
wherein the connection portion (<NUM>, <NUM>', <NUM>, <NUM>') is located in or on the implant and configured in such a way that it permits to selectively connect at least two different holding members (<NUM>, <NUM>, <NUM>) to the implant; and
wherein the implant comprises at least one further connection portion (<NUM>, <NUM>') that is configured to be engaged by the engagement portion (<NUM>, <NUM>) of the holding member (<NUM>, <NUM>) of the insertion device or the secondary device, wherein the further connection portion is configured to be engaged so that the holding member and the implant can form only a single angle with respect to each other.