INTERSPINAL IMPLANT AND ASSOCIATED IMPLANTATION AID

Description

[0001] The invention relates to the technical field of interspinous vertebral implants, and also to ancillaries for installing such interspinous vertebral implants.

[0002] Interspinous vertebral implants are implants intended to be located between the spinous processes of two adjacent vertebrae. Such implants allow the distraction of two adjacent spinous processes from each other, i.e., the achievement of a separation or spacing between them.

[0003] The invention finds its application in particular in the treatment of lower back pain for example.

[0004] An interspinous vertebral implant known from the state of the art, in particular from document US 2012 / 0265246, comprises an implant body comprising a central part, intended to extend between two adjacent spinous processes, a front part, having a profiled shape adapted to gradually separate the spinous processes of the vertebrae and make its way between the two vertebrae and a guide channel in the form of a rectilinear guide hole provided through the implant body, opening only on the front and rear ends of the implant body, and intended to receive a guide needle.

[0005] Surgery is required to place the implant between two vertebrae. This procedure can be percutaneous or open and is performed using a lateral approach to the patient as per US 2012 / 0265246, although a dorsal approach is also possible but with other models of interspinous vertebral implants. In all cases, such a procedure requires substantial equipment to identify the exact location of the implantation and navigate to that location.

[0006] Indeed, according to document US 2012 / 0265246, a guide needle is used in particular, designed to engage in the straight guide hole made in the implant to guide it during its implantation, and along which two types of tools make it possible to clear the tissues blocking access to the intervertebral space and partially or temporarily separate the spinous processes for better implantation. The first tool has a screw-shaped or smooth profiled head and slides along the guide needle. The first tool is configured to temporarily separate the spinous processes while severing the interspinous ligament.

[0007] Once this first clearance has been made, a second tool is inserted along the guide needle, the second tool having the same overall shape as the first tool but being larger in size, so as to clear more tissue and prepare the implantation site more thoroughly. It is described that several tools may be used successively, until the site is completely cleared or is of sufficient size to receive the implant. The implant is then placed in the cleared site by sliding along the guide needle.

[0008] This known and described method is restrictive, because it requires several operations to place the implant, it requires a significant number of tools before implantation. In addition, surgery by lateral approach is often performed under general anesthesia which involves a long, complex procedure, with a large opening in the patient. In addition, the risk of malposition is significant due to the distance between the skin and the insertion area.

[0009] The state of the art can also be illustrated by the teachings of document US8672977 which discloses an interspinous vertebral implant comprising an articulated type implant body, provided with a plurality of successive and interconnected segments, to be first in a linear configuration (for its insertion) then in a curved configuration (once implanted between two adjacent spinous processes). Thus, at rest, this implant body is in a linear configuration and it is crossed by a flexible contraction element which passes through a channel which is in the form of aligned holes arranged in the segments. At rest, these holes are aligned and the channel is linear for an introduction of the flexible contraction element, which will be used to pull on a segment at the front of the implant body, in order to be able to make it pass from the linear configuration to the curved configuration.

[0010] The implant described in this document US8672977, however, has the disadvantage of being formed of an articulated body, which passes from the linear configuration to the curved configuration, which gives it reduced mechanical strength, and is necessarily less reliable for ensuring a distraction function of two adjacent spinous processes. Furthermore, when passing from the linear configuration to the curved configuration during its implantation, there are risks of material jamming between the segments of the implant body which are first spaced apart and then in contact, which can cause pinching and damage to the patient, and also hinder implantation.

[0011] The invention aims, among other things, to do without an articulated implant body, by retaining the use of a non-articulated implant body which is more reliable and less traumatic during its implantation.

[0012] It is also known from document US9101409 to use an interspinous vertebral implant comprising an implant body of the revolution ogive type, comprising a rear part, a refined central part and a tapered front part, where an axial hole is provided in the center of the implant body to pass through it along its entire length; this axial hole being used to slide the implant body along a rectilinear guide rod according to a lateral approach route by means of a pusher screwdriver which has a hexagonal head fitted into a hexagonal orifice provided at the rear of the axial hole, so that the implant is put in place by a movement combining a lateral push and a rotation, which is equivalent to an implantation by "screwing".It should be noted that the implant body also has grooves arranged in the longitudinal direction on half of the front part, the entire central part and half of the rear part; such grooves being very fine and intended to give flexibility to the implant, in order to allow it to contract during its implantation and thus reduce stress on the patient.

[0013] As previously mentioned, due to its implantation via a lateral approach, the implant of document US9101409 has disadvantages in terms of the complexity of the implantation procedure, which is mostly blind and therefore unreliable, and also in terms of trauma for the patient, despite the grooves which may be insufficient to reduce such stress. Furthermore, its implantation by "screwing" induces torsions on the tissues and on the spinous processes, which can be sources of trauma.

[0014] It is also known from document US2012 / 0226313 to use an interspinous vertebral implant comprising an implant body of arcuate shape, provided with a lateral slot intended to receive two locking fingers, and provided with a screw at the rear suitable for applying a tightening force to one of the two locking fingers; the two locking fingers being provided to embed on the right and left the two adjacent spinous processes, while the implant body is housed between these two spinous processes. Such an implant nevertheless has limited mechanical reliability with an implant composed of three elements (an implant body and two locking fingers) which must be assembled together.This implant cooperates with a placement ancillary comprising a platform centered on a punch and which serves as a support for the other elements, with a major drawback which is the instability of such a platform during all operations, not to mention its traumatic aspect because it requires several incisions, one to pass the implant body and one or two others to pass the two locking fingers. The other elements are a curved pin of 90 degree arc shape which is integral with a pivotally articulated lever arm on the platform, and a curved guide tube which defines a curved channel and which is integral with a pivotally mounted lever arm on the platform.During implantation, once the platform is in place, and despite its lack of stability, the curved pin pivots on the platform to position its tip between the two spinous processes, then the curved guide tube also pivots on the platform while being guided by the curved pin which is in the curved canal. Then, the curved pin is removed, and it is then possible to push the implant body inside the curved canal of the curved guide tube, until it is positioned between the two spinous processes. Finally, the two guide fingers will slide into two other curved tubes also pivotally mounted on the platform.The implantation method described in this document US2012 / 0226313 has several drawbacks, including the lack of stability of the platform previously mentioned, as well as the traumatic insertions of the curved pin and the three curved tubes due to their 90-degree arched shapes which give them dimensions such that their implantation will necessarily be traumatic because their insertions require long movements.

[0015] The invention aims to remedy all or part of the aforementioned drawbacks by proposing an interspinous vertebral implant adapted to a simpler implantation method, primarily dorsal and minor lateral, i.e. which uses a dorsal approach but slightly eccentric from the dorsal axis (or axis of the spinal column). Indeed, the patient is opened on the back on a minimum necessary portion determined according to the insertion zone of the implant and according to the size of the implant and the size of the implantation tool, which allows reliable and precise implantation of the implant under local anesthesia, and therefore without heavy surgical intervention with general anesthesia, thus minimizing the risks of postoperative complications.

[0016] The invention also proposes a placement ancillary specially adapted for an interspinous vertebral implant according to the invention, and which is adapted to a method of implantation between the spinous processes of two adjacent vertebrae (and not between the vertebral endplates) which is simpler, mainly dorsal.

[0017] To this end, the invention relates to an interspinous vertebral implant comprising an implant body extending along a longitudinal axis and comprising successively along said longitudinal axis: a rear portion having a rear end, a central portion shaped to extend between two spinous processes of two adjacent vertebrae, said central portion extending the rear portion, and a front portion extending the central portion, opposite the rear portion, tapering to a tapered front end, wherein said implant body has: an anterior face intended to be oriented towards the vertebrae, a guide channel provided in the implant body from its rear end to its front end, said guide channel being shaped to receive at least a portion of an implantation pin of a placement ancillary; said interspinous vertebral implant being remarkable in that the guide channel extends from the rear end to the front end in a curvilinear direction, said guide channel being provided in the anterior face so that said guide channel forms an anterior groove of curvilinear shape and opening externally into said anterior face of the implant body.

[0018] Thus, such an implant according to the invention makes it possible, thanks to such an anterior groove, to receive an implantation pin curved in a predetermined manner. Consequently, such an implant according to the invention allows an intervention using a predominantly dorsal approach, which is difficult to envisage, or even impossible, with a rectilinear guide hole of the state of the art. Indeed, its curvilinear shape allows an intuitive and progressive insertion between the vertebrae by using a dorsal opening, slightly eccentric from the dorsal axis, thus promoting a direct implantation in the determined implantation zone.

[0019] In the present invention, the following terms are defined: by "front" is meant the part of the implant body that is intended to penetrate the patient's body first, by "rear" is meant the part of the implant body that is intended to penetrate the patient's body last, by "tapered shape" is meant the shape of the front end that tapers in the longitudinal direction in a back-to-front direction, by "curvilinear direction" is meant that the direction of the through channel follows a curve, not a straight line, and for example an arc curve of a given radius of curvature; by "anterior face" is meant the anatomy of the patient to indicate a face facing the vertebrae; by "posterior face" is meant the anatomy of the patient to indicate a face facing away from the vertebrae, on the skin side of the back;by "lower face" we refer to the patient's anatomy to indicate a face facing a spinous process of the underlying vertebra (vertebra below); by "upper face" we refer to the patient's anatomy to indicate a face facing a spinous process of the overlying vertebra (vertebra above). The implant according to the invention may comprise one or more of the following characteristics taken alone or in combination. ;

[0020] According to one feature, the anterior groove is provided continuously (in other words without interruption or cut) in the anterior face of the implant body from the rear end to the front end, so as to open continuously into the anterior face.

[0021] According to another characteristic, the implant body is non-articulated, so that, in a resting position (before implantation) as in an implanted position (once implanted between the two spinous processes), the anterior groove is curvilinear in shape with the same curvature.

[0022] According to another characteristic, the anterior groove is convex in shape according to a given radius of curvature, with a center of curvature located opposite a posterior face of the implant body, opposite the anterior face.

[0023] The convex shape, which corresponds to a curvilinear direction in an arc of a circle, is advantageous because it allows the implant to move from a vertical orientation to a horizontal orientation according to a smooth and smooth guidance path of the implant throughout its insertion.

[0024] According to one possibility, the anterior face is convex in shape according to the radius of curvature.

[0025] Thus, the implant can also be guided by this anterior face, which is also curved.

[0026] According to another possibility, the anterior groove is delimited internally by a bottom wall offset in depth relative to the anterior face, said bottom wall being convex in shape according to a given radius of curvature.

[0027] Thus, the implant can also be guided by this equally curved back wall.

[0028] According to a variant, the bottom wall and the front face have the same center of curvature, and the radius of curvature of the bottom wall is less than the radius of curvature of the front face.

[0029] According to another possibility, the front groove is delimited externally by retaining lips of convex shape according to the radius of curvature, said retaining lips being arranged opposite the bottom wall and extending opposite each other to delimit a space narrowed compared to the interior of the front groove.

[0030] Thus, the anterior groove has a “C” section, with retaining lips at the ends of the “C” which will provide a function of retaining the implant, in other words holding the implant on the implantation pin without the risk of it coming out of the implantation pin during insertion.

[0031] In a particular embodiment, the radius of curvature is between 20 and 300 millimeters.

[0032] An advantage provided by such radii of curvature is to facilitate the surgical intervention using a predominantly dorsal approach (with a dorsal opening slightly eccentric in relation to the dorsal axis), and to limit the size of the incision.

[0033] In a particular embodiment, the rear part has pivoting means along a transverse axis extending transversely relative to the longitudinal axis to allow pivoting of the implant body relative to complementary pivoting means provided on an implant holder of the insertion ancillary.

[0034] Thus, these pivoting means will allow the implant to pivot easily during its insertion, its insertion being carried out following an insertion trajectory having at least one curvilinear component, which will facilitate this insertion because the implant will be coupled and held by this implant holder along this curvilinear component of the trajectory.

[0035] According to one characteristic, the rear part has two opposite lateral faces, respectively an upper face and a lower face, and the pivoting means are provided on said opposite lateral faces in the form of recesses or protrusions shaped at least partially in an arc of a circle centered on the transverse axis.

[0036] Thus, the pivoting means operate by form cooperation, the complementary pivoting means provided on the implant holder being of complementary shapes for a coupling by form cooperation which allows relative pivoting between the implant and the implant holder.

[0037] In a particular embodiment, the front portion comprises facets directly connected to each other by sharp edges converging towards the tapered front end.

[0038] The advantage of sharp edges is that they can easily puncture and cut the interspinous ligament and clear a path for the implant.

[0039] According to one variant, the tip and the facets of the front part define a volume of truncated, pyramidal or trapezoidal shape. An advantage provided by such a shape is to facilitate the perforation of the ligamentous areas while remaining compact. According to one variant of the invention, the sharp edges can be obtained by a profile using simple machining.

[0040] According to a variant of the invention, at least one of the sharp edges and preferably all the sharp edges are straight, which allows clean perforation of the ligament areas.

[0041] In an advantageous embodiment, the rear portion comprises, at an interface with the central portion, at least one locking fin projecting on a lower side of the rear portion or on an upper side of the rear portion, opposite the lower side. Also, the or each locking fin extends to the front of the rear portion, and therefore to the rear of the central portion, between the rear portion and the central portion, and it forms a fin suitable for abutting against a spinous process, so as to stop the implant in its insertion trajectory and ensure precise positioning between the two spinous processes. Thus, when the implant is placed, the or each locking fin prevents the implant from moving out of the interspinous space by each pressing against an adjacent spinous process, in order to prevent involuntary removal of the implant.

[0042] Advantageously, the rear portion comprises, at the interface with the central portion, a blocking fin projecting on the lower side of the rear portion and another blocking fin projecting on the upper side of the rear portion.

[0043] According to a variant, the two locking fins are coplanar.

[0044] According to another variant, the two locking fins are identical and symmetrical with respect to a median plane containing the longitudinal axis.

[0045] According to one possibility, the at least one locking fin extends from the relevant side of the rear part in a plane orthogonal to the longitudinal axis or inclined relative to the longitudinal axis by an angle of between 60 and 120 degrees.

[0046] Thus, when the or each locking fin extends from the rear part in a plane substantially perpendicular to the longitudinal axis of the implant body, it is naturally anchored on the corresponding spinous process.

[0047] Alternatively, the at least one locking fin is fixed or hinged to the rear portion.

[0048] The advantage of a fixed locking fin is that it provides an easy and inexpensive implant body design.

[0049] In the case where the locking fin is articulated, it is then movable between at least one deployed position in which it extends along an axis substantially perpendicular to the longitudinal axis of the implant body and a folded position in which it extends, preferably against the relevant side of the rear part, along an axis substantially parallel to the longitudinal axis of the implant body.

[0050] According to another possibility, the at least one locking fin has a front face facing towards the front end and on which is provided at least one anchoring relief configured to allow anchoring on a spinous process, such as for example a spike-shaped anchoring relief.

[0051] This front face is intended to be opposite one of the spinous processes, and the anchoring relief(s) will provide stable anchoring in this spinous process in the final position of the implant.

[0052] According to one variant, the at least one locking fin has several anchoring reliefs.

[0053] According to another variant, the at least one spike extends along an axis substantially parallel to the longitudinal axis of the implant.

[0054] According to another variant, the front face of the at least one locking fin is coated with an osseointegration material, promoting adhesion between the bone and the implant body, such as for example a porous material.

[0055] In a particular embodiment, the central part has two opposite lateral faces, respectively an upper face and a lower face, which are concave to define two hollow lateral faces suitable for being inserted between the two spinous processes.

[0056] It should be noted that the upper face of the central part is intended to rest on the apophysis of the overlying vertebra, while the lower face of the central part is intended to rest on the apophysis of the underlying vertebra. Thus, this hollow shape of these two faces makes it possible to fit the base of the two spinous processes and also promotes a slight elastic deformation suitable for ensuring flexible distraction between the adjacent spinous processes, one in relation to the other and thus reducing the lordosis at this level.

[0057] According to one variant, the implant body is made of at least one biocompatible sterilizable material. By way of non-limiting examples, the implant body may be made of a material selected from titanium, a titanium-based alloy, steel, a biocompatible plastic material such as PolyEtherEtherKethone (PEEK), polymethyl methacrylate (PMMA), etc.

[0058] The invention also relates to a placement ancillary, provided for guiding and positioning an interspinous vertebral implant according to the invention between two spinous processes of two adjacent vertebrae, this placement ancillary comprising: an implant holder having an opposite distal portion and a proximal portion, said distal portion being provided with shaped support means to support said interspinous vertebral implant; an implantation pin having a distal termination portion which extends to a free, pointed distal end, said distal termination portion having a curved shape and on which is provided a curved guide rail of a shape complementary to the anterior groove of the interspinous vertebral implant to allow sliding guidance of said interspinous vertebral implant along a posterior face of said distal termination portion by engagement of the guide rail inside the anterior groove, said guide rail extending to the free distal end.

[0059] Thus, the interspinous vertebral implant can be guided by the guide rail of this curved implantation pin, along an at least partially curvilinear trajectory which allows intuitive and progressive insertion between the two spinous processes of the vertebrae. In other words, the implant, with its anterior groove, can be positioned and slid on the curved implantation pin to allow an intervention using a predominantly dorsal approach, along a curvilinear trajectory (allowed by the shape of the curved implantation pin) and using a dorsal opening, slightly off-center from the dorsal axis, thus favoring direct implantation in the determined implantation zone.

[0060] In other words, thanks to such an implantation ancillary according to the invention, the implantation pin is oriented in a curved manner on its distal end portion, which allows a surgical intervention using a predominantly dorsal approach. In addition, due to its anterior position relative to the implant, the implantation pin protects the nerve elements present in the vertebral canal.

[0061] It should be noted that, within the meaning of the invention, the implantation pin forms an elongated body, in particular of curved shape, ending in a free distal end in the form of a point, so as to be able to penetrate, by making its way through the tissues, into the patient's body to an appropriate position opposite the interspinous space, between the two spinous processes, which is a classic function of a pin in the surgical field.Furthermore, this implantation pin has the previously described feature, namely the presence of a guide rail on which the interspinous vertebral implant is guided in sliding; this sliding necessarily takes place on the implantation pin (in other words the implant is outside the implantation pin), and not inside the implantation pin, because in the surgical field, it is well understood that a pin does not form a channel or a tube inside which an implant could slide.

[0062] It should also be noted that the guide rail provided on the implantation pin has the function of guiding the interspinous vertebral implant along a curved implantation trajectory, but it also necessarily has the function of preventing or limiting lateral movement of the implant to prevent it from coming out of the guide rail.

[0063] Advantageously, the positioning of the curved distal end portion of the implantation pin will be as far anteriorly as possible at the level of the interspinous space because the optimal location of the implant at the end of the procedure corresponds to the anterior part of the interspinous space, the area where the bone is widest and strongest. The curvilinear direction of the guide groove is thus chosen so that the implantation pin has a satisfactory angle of attack to access the interspinous space.

[0064] In the present invention, the notion of "proximal" refers to a part or end closest to the surgeon's hand during placement of the implant, and the notion of "distal" refers to a part or end furthest from the surgeon's hand during placement, or in other words closest to the patient at the time of the intervention.

[0065] According to one feature, the implantation pin is solid, and it does not form a tube or a chute.

[0066] According to one possibility, the distal termination portion of the implantation pin is curved in an arc of a circle over an angular sector between 60 and 120 degrees.

[0067] In a particular embodiment, the distal termination portion of the implantation pin is curved in an arc of a circle with a radius of curvature of between 20 and 300 millimeters.

[0068] An advantage provided by such radii of curvature is to facilitate the surgical intervention using a predominantly dorsal approach, and to limit the size of the incision.

[0069] Alternatively, the implantation pin includes a proximal termination portion that extends the distal termination portion to a free proximal end, and the guide rail is extended from the distal termination portion by a longitudinal rail provided on the proximal termination portion to the proximal end.

[0070] Thus, the interspinous vertebral implant can be slid onto the longitudinal rail at the proximal end, to slide toward the curved distal end portion to pass into the curved guide rail to slide and follow a curvilinear path.

[0071] It is clear that, within the meaning of the invention, the guide rail and the longitudinal rail can form a single continuous rail on which the interspinous vertebral implant can engage from the proximal end to the distal end.

[0072] In other words, the guide rail and the longitudinal rail are provided together on the implantation pin with the function of guiding the interspinous vertebral implant along a complete rectilinear then curved implantation trajectory, but this guide rail and this longitudinal rail also necessarily have the function of preventing or limiting lateral movement of the implant to prevent it from coming out of the guide rail and the longitudinal rail.

[0073] According to one possibility, at least one of the proximal termination portion and the longitudinal rail is straight, in other words this proximal termination portion is straight and / or this longitudinal rail is straight.

[0074] Thus, the interspinous vertebral implant will follow an insertion trajectory having first a linear component (sliding on the longitudinal rail) and then finally a curvilinear component (sliding on the curved guide rail), which allows the implant to move from a vertical orientation (outside the patient) to a horizontal orientation (inside the patient in the interspinous space).

[0075] According to one characteristic, the guide rail is provided on at least one external face of the distal termination portion of the implantation pin.

[0076] In other words, the guide rail is provided on the outside of the implantation pin, so that the implant slides on the implantation pin (and not inside a tube or a chute).

[0077] According to another feature, the free, pointed distal end of the implantation pin has a point angle of less than or equal to 90 degrees, and preferably less than or equal to 60 degrees, or even less than or equal to 45 degrees. Indeed, a low point angle promotes the penetration of the implantation pin through the tissues.

[0078] In a particular embodiment, the distal termination portion of the implantation pin has two opposite lateral faces, respectively an upper face and a lower face, and the guide rail is formed in the form of two notches formed in said respective lateral faces.

[0079] Such notches are adapted to receive the retaining lips described above and thus provide stable and reliable guidance over the entire distance.

[0080] According to one characteristic, the distal termination portion of the implantation pin has an anterior face, opposite the posterior face along which the interspinous vertebral implant slides, and on which a first pivoting guide means is provided, and the implantation ancillary comprises a primary support having a distal part on which at least one anchoring relief is provided for anchoring in a vertebra, and a second pivoting guide means suitable for cooperating with the first pivoting guide means to guide said implantation pin in pivoting during insertion of its distal termination portion between the two spinous processes.

[0081] Thus, this primary support will be anchored in a vertebra, in an area located in a median plane passing between the two spinous processes, and then this primary support will be used to direct the implantation pin to bring its distal termination portion between the two spinous processes, according to a pivoting or tilting movement of the implantation pin.

[0082] In a particular embodiment, the first pivoting guide means and the second pivoting guide means respectively comprise an arcuate rail and an arcuate slide of complementary shapes.

[0083] According to a variant, the first pivoting guide means and the second pivoting guide means are shaped to guide the implantation pin in pivoting at a pivoting angle of between 60 and 120 degrees, and in particular of the order of 90 degrees.

[0084] According to another characteristic, the primary support has a proximal part coupled to a holding handle provided with a gripping head.

[0085] The main function of such a holding handle is to allow gripping by the surgeon and therefore to allow the surgeon to position and maintain the primary support in order to anchor it in the vertebra, in particular by exerting a pushing force, and if necessary an impaction force on the gripping head, preferably repeated, to push in the primary support.

[0086] According to one variant, the grab handle is separate from the primary support and is secured to the primary support or the grab handle and the primary support are made in one piece.

[0087] According to another characteristic, the primary support has a distal hole opening into a distal face of the distal part of the primary support, and the placement ancillary comprises a positioning pin provided with a point intended for anchoring in a vertebra, said positioning pin being shaped to guide the primary support longitudinally in sliding by insertion of the positioning pin inside the distal hole.

[0088] Thus, this positioning pin will be anchored in a vertebra, at a precise point determined by the surgeon and located approximately in the median plane passing between the two spinous processes, and it will be used to guide the primary support to position it in the desired area.

[0089] In a particular embodiment, the support means provided on the distal part of the implant holder comprise complementary pivoting means shaped to cooperate with the pivoting means of the rear part of the interspinous vertebral implant in order to allow pivoting of this interspinous vertebral implant along a transverse axis.

[0090] According to one possibility, the support means comprise two support elements having facing internal faces provided respectively with recesses or protrusions shaped at least partially in an arc of a circle centered on the transverse axis and forming the complementary pivoting means.

[0091] Thus, the interspinous vertebral implant is wedged between the internal faces of the two respective support elements, while being pivotally movable between these two internal faces.

[0092] Furthermore, the pivoting means operate by form cooperation, the complementary pivoting means provided on the implant holder being of complementary shapes for a form cooperation coupling which allows relative pivoting between the implant and the implant holder.

[0093] Alternatively, the two support members are detachably attached to each other and, for this purpose, are provided with removable attachment means so that the two support members are configurable between an attached configuration to be able to support the interspinous vertebral implant, and a detached configuration to be able to release the interspinous vertebral implant from the implant holder.

[0094] In this way, once the interspinous vertebral implant is in place between the two spinous processes, it is sufficient to detach the two support elements from each other to be able to release the interspinous vertebral implant and thus remove the implant holder while leaving the interspinous vertebral implant in place.

[0095] According to one possibility, the removable attachment means are formed of an upper slide and an upper rail which are provided on the respective support members.

[0096] Alternatively, the upper slide and the upper rail are both arched and of complementary shapes and extend between an anterior face and a posterior face of the distal portion of the implant holder, to form pivoting guide means suitable for cooperating together to pivotally guide one support element relative to the other support element along the transverse axis. Thus, the detachment between the two support elements is achieved by pivoting, without interfering with the implant.

[0097] Alternatively, the distal portion and the proximal portion of the implant holder are connected by two rods, these rods having distal ends fixed to the respective support elements and proximal ends, opposite their distal ends, which are removably fixed to the proximal portion.

[0098] Advantageously, the distal ends of the rods have respective terminations which protrude from the respective support elements, in order to be able to bear against respective locking fins of the implant.

[0099] In a particular embodiment, the placement ancillary comprises an impactor removably mounted on the proximal part of the implant holder.

[0100] According to one feature, the impactor comprises an impaction rod provided with a distal end fixed to the proximal part of the implant holder, and a distal end, opposite the distal end, and on which a handle is fixed.

[0101] According to another characteristic, the impactor further comprises an impaction sleeve slidably mounted around the impaction rod, between the handle and the proximal part of the implant holder.

[0102] Other characteristics and advantages of the present invention will appear on reading the detailed description below, of a non-limiting example of implementation, made with reference to the appended schematic figures in which: [ Fig. 1 ] is a perspective illustration on the posterior side of an example of an interspinous vertebral implant according to the invention; [ Fig. 2 ] is a front (front side) illustration of the implant of the Figure 1 ; [ Fig. 3 ] is an illustration from below (inner side) of the implant of the Figure 1 ; [ Fig. 4 ] is a perspective illustration of the anterior side of the implant of the Figure 1 ; [ Fig. 5 ] is a back (rear side) illustration of the implant of the Figure 1 ; [ Fig. 6 ] is an illustration of the posterior side of the implant of the Figure 1 ; [ Fig. 7 ] is an illustration of the anterior side of the implant of the Figure 1 ; [ Fig. 8 ] is a perspective illustration (back and posterior side view) of the implant of the Figure 1 located between two spinous processes; [ Fig. 9 ] is a view is a perspective illustration (front and posterior side view) of the implant of the Figure 1 located between two spinous processes; [ Fig. 10 ] is an illustration of the posterior side of the implant of the Figure 1 located between two spinous processes; and [ Fig. 11 ] is an illustration of a first step of inserting a positioning pin of the installation ancillary according to the invention; [ Fig. 12 ] is an illustration of a second step of inserting a primary support of the installation ancillary according to the invention; [ Fig. 13 ] is a perspective illustration of the distal portion of the primary support of the Figure 12 , according to two distinct angles of view; [ Fig. 14 ] is an illustration of a third step of coupling a holding handle to the primary support, and of a fourth step of inserting an implantation pin of the implantation ancillary according to the invention; [ Fig. 15 ] is a perspective illustration of the grab handle alone of the Figure 14 ; [ Fig. 16 ] is a zoomed and perspective illustration of the distal portion of the primary support on which the distal termination portion of the implantation pin is guided during the fourth step of the Figure 14 ; [ Fig. 17 ] is a perspective illustration of the implantation pin alone of the Figure 14 , from several viewing angles and in full (the left view) or in part (the three right views); [ Fig. 18 ] is an illustration of a fifth stage of pivoting (or tilting) the implantation pin relative to the static primary support; [ Fig. 19 ] is a perspective illustration of an assembly of the implantation ancillary according to the invention, comprising an ancillary holder supporting the implant of the Figure 1 , and further comprising an impactor mounted on the implant holder; [ Fig. 20 ] is a perspective illustration of the implant holder alone of the Figure 19 ; [ Fig. 21 ] is a perspective illustration of the distal portion of the implant holder of the Figure 19 , with its two support elements in attached configuration (left) and in detached configuration (right); [ Fig. 22 ] is an illustration of a sixth step of insertion of the ancillary holder and impactor assembly of the Figure 19 , the ancillary holder supporting the implant of the Figure 1 ; [ Fig. 23 ] is a zoomed-in, perspective illustration of the distal portion of the primary support and the distal termination portion of the implantation pin over which the implant carried by the implant holder slides. Figure 19 ; [ Fig. 24 ] is a zoomed-in, perspective illustration of the distal portion of the primary support and the distal termination portion of the implantation pin over which the implant carried by the implant holder slides. Figure 19 ; [ Fig. 25 ] is an illustration of the beginning of a seventh stage of pushing of the implant of the Figure 1 which slides on the implantation pin towards the interspinous space between the two spinous processes; [ Fig. 26 ] is a zoomed-in, perspective illustration of the implant sliding onto the implantation pin at the start of the seventh stage of the Figure 25 ; [ Fig. 27 ] is an illustration of the end of the seventh stage of implant pushing of the Figure 1 which has slid onto the implantation pin and is now positioned between the two spinous processes; [ Fig. 28 ] is a zoomed-in, perspective illustration of the implant on the implantation pin at the end of the seventh stage of the Figure 27 ; [ Fig. 29 ] is an illustration of an eighth step of removing the impactor from the implant holder; [ Fig. 30 ] is an illustration of a ninth step of unlocking the implant holder by moving its two support elements into a detached configuration; [ Fig. 31 ] is a zoomed-in, perspective illustration of the implant and implant holder during the ninth stage of the Figure 30 ; And [ Fig. 32 ] is an illustration of a tenth step of removing the implantation pin, after removing the implant holder following the ninth step of the Figure 30 .

[0103] Identical elements or those providing the same function will bear the same references for the different embodiments, for the sake of simplification.

[0104] The implant 1 according to the invention will now be described with reference to figures 1 à 7 . This implant 1 according to the invention is an interspinous vertebral implant comprising an implant body 10 made from at least one biocompatible material. More precisely, this implant 1 is formed entirely and solely from this implant body 10.

[0105] This implant body 10 extends along a longitudinal axis AL and it successively comprises along this longitudinal axis AL: a rear part 2 having a rear end 20, a central part 3 shaped to extend between two spinous processes AE (as visible on the Figures 8 à 10 ) of two adjacent VE vertebrae, this central part 3 extending the rear part 2, and a front part 4 extending the central part 3, in a manner opposite to the rear part 3, tapering to a front end 40 of tapered shape.

[0106] Thus, the central part 3 connects the rear part 2 to the front part 4, and this central part 3 extends between the rear part 2 to the front part 4.

[0107] It should be noted that the central part 3 may have a certain elasticity, compared to the front part 2, allowing flexion of the central part 3 during its insertion trajectory, in particular during the curvilinear component of this insertion trajectory. Once inserted, this flexibility of the implant body 1 makes it possible to preserve mobility between the two adjacent vertebrae within a given range. This elasticity of the central part 3, which contributes to having an implant body 10 with two "zones" of different rigidity / flexibility, can for example be obtained by geometric modifications (eg. lattice-type structure) and / or by the use of different materials.

[0108] The rear part 2 has a general half-disc shape with its rear end 20 which is rounded or rather semi-cylindrical in shape centered on a transverse axis AT which is perpendicular to the longitudinal axis AL.

[0109] This rear part 2 has two opposite lateral faces 21, 22, respectively an upper face 21 and a lower face 22, in the general shape of a half-disc, and pivoting means along the transverse axis AT are provided on these two lateral faces 21, 22. To do this, the pivoting means are provided in the form of recesses 23 formed in the respective lateral faces 21, 22 and shaped at least partially in an arc of a circle centered on the transverse axis AT. As seen in Figure 3 , a recess 23 is in the form of a recess in the shape of an arc of a circle along an angular sector of less than 180 degrees, such as, for example and without limitation, an angular sector of between 20 and 175 degrees.

[0110] As explained later, these recesses 23 are provided to cooperate with complementary protrusions 941, 951 provided on an implant holder 9 to allow relative pivoting of the implant body 10 on this implant holder 9 along the transverse axis AT.

[0111] At the junction between the rear part 2 and the central part 3, the rear part 2 comprises a locking fin 24 projecting on the lower side of the rear part 2 (on the same side as the lower face 22) and another locking fin 24 projecting on the upper side of the rear part 2 (on the same side as the upper face 21).

[0112] The two blocking fins 24 are symmetrical with respect to a median plane PM including the longitudinal axis AL and orthogonal to the transverse axis AT, and the blocking fin 24 extends perpendicular to the lower face 22 while the other blocking fin 24 extends substantially perpendicular to the upper face 21.

[0113] These locking fins 24 are coplanar, extending in a plane substantially orthogonal to the longitudinal axis AL, or more generally in a plane inclined relative to the longitudinal axis AL by an angle of between 60 and 120 degrees. Generally, the implant body 10 is symmetrical relative to this median plane PM.

[0114] The two locking fins 24 project outwardly relative to the respective lateral faces 21, 22, and also relative to the central part 3. The two locking fins 24 are fixed and are integral with the implant body 10. In a variant not illustrated, the locking fins 24 are articulated on the respective lateral faces 21, 22 or the locking fins 24 are removably mounted on the lateral faces 21, 22.

[0115] The two locking fins 24 each have a front face 240 facing the front end 40, and a rear face 241 opposite the front face 240 and facing the rear end 20.

[0116] On each of the front faces 240 of the two locking fins 24 are provided several pins 25 forming anchoring reliefs configured to allow anchoring on a spinous process AE. These pins 25 extend in directions parallel to the longitudinal axis AL. The rear faces 241 of the two locking fins 24 are smooth.

[0117] The central part 3 has two opposite lateral faces 31, 32, respectively an upper face 31 and a lower face 32, which are concave to define two hollow lateral faces 31, 32 suitable for being inserted between the two spinous processes AE. In other words, the central part 3 is thinned in its center to match the shape of the spinous processes AE. The two locking fins 24 project outwardly relative to the respective lateral faces 31, 32.

[0118] The front part 4 has a tapered shape suitable for perforating ligamentous areas, and for this it comprises flat facets directly connected to each other by sharp, rectilinear edges converging towards the front end 40 tapered to a point.

[0119] The implant body 10 also has an anterior face 11 intended to be oriented towards the vertebrae VE, and a posterior face 12, opposite the anterior face 11.

[0120] The anterior face 11 has a convex shape with a radius of curvature RC of between 20 and 300 millimeters, with a center of curvature located opposite the posterior face 12 of the implant body 10. The posterior face 12 has a convex shape at the central part 3 and a flat facet shape at the front part 4.

[0121] The implant body 10 also has an anterior groove 5 formed in the anterior face 11 and passing entirely through the implant body 10 from its rear end 20 to its front end 40 to form, as described later, a guide channel shaped to receive at least a portion of an implantation pin 8 of a placement ancillary described below.

[0122] As clearly visible on the Figures 4 And 7 , this anterior groove 5 is provided continuously in the anterior face 11 of the implant body 10 from the rear end 20 to the front end 40, so as to open continuously into the anterior face 11.

[0123] This front groove 5 is convex in shape according to the radius of curvature RC, and therefore extends from the rear end 20 to the front end 40 in a curvilinear direction in an arc of a circle. This front groove 5 extends in the median plane PM and is symmetrical with respect to the median plane PM.

[0124] Although a certain flexibility is conceivable for the implant body 10, this implant body 10 in no case forms an articulated body, in other words this implant body 10 is non-articulated, in the sense that in a rest position (position visible on the Figures 1 à 7 ) as in an implanted position (position visible on the Figures 8 à 10 And 27 à 32 ), the anterior groove 5 is curvilinear in shape with the same curvature.

[0125] The front groove 5 is delimited internally by a bottom wall 50 offset in depth relative to the front face by a given depth PR constant from the rear end 20 to the front end 40, as visible in Figure 5 .

[0126] This bottom wall 50 is convex in shape with a center of curvature coinciding with the center of curvature of the front face 11 and having a radius of curvature RP (not shown) less than the radius of curvature RC of this front face 11. The depth PR is measured in a radial direction passing through the center of curvature, so that RC = RP + PR.

[0127] This anterior groove 5 is also delimited internally by two side walls 51, 52 parallel to the median plane PM and in the shape of an arc of a circle. The spacing between the two side walls 51, 52 defines the width LA of the anterior groove 5.

[0128] The front groove 5 is delimited externally by retaining lips 53 of convex shape according to the radius of curvature RC at the level of the front face 11. These retaining lips 53 project from the respective side walls 51, 52, moreover they are arranged opposite the bottom wall 50 and they extend opposite each other to delimit a space narrowed compared to the interior of the front groove 5. In other words, the spacing EC between the two retaining lips 53 is less than the width LA of the front groove 5. These retaining lips 53 are an integral part of the front face 11 into which the front groove 5 opens. The retaining lips 53 each have a lip thickness or height HL, as visible in Figure 5 , measured in a radial direction passing through the center of curvature. Thus, the front groove 5 has a groove height HR, also measured in a radial direction passing through the center of curvature, between the retaining lips 53 and the bottom wall 50, which is such that: PR = HR + HL.

[0129] Furthermore, the front groove 5 is shaped so that: considering a first directrix and a second directrix parallel to the longitudinal axis AL, where the first directrix passes through the lowest point of the bottom wall 50 (substantially halfway between the rear end 20 and the front end 40) and the second directrix passes through the highest point of the retaining lips 53 (at the rear end 20 or the front end 40), then the front groove 5 has a non-zero intermediate height HI, which corresponds to a distance measured between the first directrix and the second directrix in a direction orthogonal to the longitudinal axis AL and to the transverse axis AT, as visible on the Figure 5 ; and considering a third director parallel to the longitudinal axis AL, where the third director passes through the lowest point of the retaining lips (substantially halfway between the rear end 20 and the front end 40), then the retaining lips 53 have an overall height HG, which corresponds to a distance measured between the second director and the third director in a direction orthogonal to the longitudinal axis AL and to the transverse axis AT, as visible on the Figure 5

[0130] Such a conformation is advantageous for allowing the implant 1 to slide on a longitudinal rail 89 (described later) along a longitudinal (in other words rectilinear) trajectory then on a curved guide rail 83 (described later) along a curved or arcuate trajectory.

[0131] The front groove 5 has at its two respective ends a rear mouth 54 open on the rear end 20, and a front mouth 55 open on the front end 40.

[0132] The rest of the description, with reference to the Figures 11 à 32 , relates to the placement ancillary intended for guiding and positioning the implant 1 between two spinous processes AE of adjacent vertebrae VE, as well as to the method of placement of the implant 1 using such a placement ancillary.

[0133] This implantation ancillary comes in the form of a kit comprising several distinct functional components which cooperate together to allow implantation using a predominantly dorsal approach to implant 1. These different components of the implantation ancillary will be described as they are used in implementing the implantation method.

[0134] As a preliminary and in reference to the Figure 11 , the surgeon determines a reference point located in a lateral part PL of a vertebra VE, at a lateral distance DL from the axis AC of the spine CV (also called dorsal axis), such a lateral distance DL being determined beforehand before the operation - for example between 5 and 70 millimeters. This reference point is located substantially in a median plane passing between the two spinous processes AE. Thus, the implantation method is said to be primarily dorsal, in the sense that it uses a dorsal approach but slightly eccentric from the dorsal axis of the lateral distance DL.

[0135] This preliminary step of determining the reference point can be carried out in advance, for example, by using a preoperative scanner. The preoperative scanner also makes it possible to measure the width of the targeted interspinous space and to choose an implant size 1 based on this width.

[0136] Next, the surgeon makes an incision at the lateral distance DL relative to the AC axis of the CV spine, above the reference point.

[0137] In a first step illustrated in Figure 11 , the surgeon separates the various elements such as tissues, muscles, ligaments, etc. using a retractor (not shown) and inserts a positioning pin 6, forming a component of the positioning ancillary, dorsally until it is anchored on the reference point.

[0138] This positioning pin 6 is a long, straight rod having a pointed distal end 61. This positioning pin 6 has a rectangular cross-section, without this shape being limiting because the positioning pin 6 can also have a circular, square, polygonal or other cross-section. The pointed distal end 61 is anchored on the reference point in the lateral part PL of vertebra VE.

[0139] This positioning needle 6 also has a proximal end 62, opposite the distal end 61, and the positioning needle 6 is long enough for this proximal end 62 to protrude from the patient's back.

[0140] In a second step illustrated in Figure 12 , the surgeon inserts a primary support 7 by sliding it onto the positioning needle 6, as shown diagrammatically by the arrow GU; this primary support 7 being another component of the insertion ancillary.

[0141] This primary support 7 is in the form of a tubular and elongated body, having an opposite distal part 71 and a proximal part 72. The distal part 71 has a distal face 710 facing the vertebra in position, from which protrude several pins 711 forming anchoring reliefs configured to allow anchoring on the lateral part PL of vertebra VE. The proximal part 72 has a proximal face 720 facing outwards, opposite the distal face 710.

[0142] The primary support 7 has a distal hole 73 (visible in Figure 13 ) opening into its distal face 710 and also has a proximal hole 730 (visible in Figure 12 ) opening into its proximal face 720; these two holes 73, 730 can both be blind or in continuity with each other.

[0143] This primary support 7 is longer than the positioning pin 6 and the distal hole 73 is substantially longer than the positioning pin 6. Thus, the positioning pin 6 is shaped to guide the primary support 7 longitudinally in sliding motion by inserting the positioning pin 6 inside the distal hole 73.

[0144] The primary support 7 is introduced from the outside at the proximal end 62, inserting itself at the proximal face 720, then the primary support 7 slides along the positioning pin 6 (as shown diagrammatically by the arrow GU) until the pins 711 come into contact with the lateral part PL of vertebra VE.

[0145] The distal portion 71 of the primary support 7 widens towards the distal face 710 and it has a front face 712, facing towards the spinous processes AE, having a curved and concave shape, from which projects a concave arcuate rail 74, having a dovetail cross-section.

[0146] In a third step illustrated in Figure 12 , the surgeon couples a holding handle 75 to the proximal portion 72 of the primary support 7, and more precisely fixes the holding handle 75 to the proximal face 720 of the primary support 7.

[0147] It should be noted that the holding handle 75 could, in a preferred variant, already be coupled to the primary support 7 during the second step described above, so that the holding handle 75 is already fixed to the primary support 7 before the insertion of this primary support 7 so that the surgeon can correctly hold and slide the primary support 7 / holding handle 75 assembly on the positioning pin 6.

[0148] This holding handle 75 comprises a main body 76 extended on one side by a gripping head 77, and on the other side by a fitting pin 78 suitable for fitting into the proximal hole 730 of the primary support 7 for coupling. The gripping head 77 is provided with two lateral wings 770 allowing manual gripping of the holding handle 7.

[0149] Advantageously, the gripping head 77 is mounted to be able to rotate through 90 degrees on the main body 76, with a locking system making it possible to lock the gripping head 77 in a first position and in a second position after having rotated through 90 degrees. Also, this locking system comprises an unlocking button 771 located on the gripping head 77, in the middle and in alignment with the main body 70 between the two lateral wings 770, and which makes it possible to unlock the rotation of the gripping head 77 to move from the first position to the second position and vice versa.

[0150] The surgeon will then exert, using the holding handle 75, a push on the primary support 7 in order to anchor it in the lateral part PL of vertebra VE, by exerting a pushing force, or even an impaction force, preferably repeated, on the gripping head 77 to push in the primary support 7.

[0151] In a fourth step illustrated in Figure 14 , the surgeon inserts an implantation pin 8, another component of the implantation ancillary. As explained later, such an implantation pin 8 can be pre-mounted on the primary support 7 so that the surgeon inserts the primary support 7 / holding handle 75 / implantation pin 8 assembly together, in a single step. This implantation pin 8 has a distal termination portion 81 which extends to a free and pointed distal end 810, and it also has a proximal termination portion 82 which extends the distal termination portion 81 to a free proximal end 820.

[0152] As visible on the Figures 16 And 17 , the free distal end 810 in the form of a tip has a tip angle of less than 90 degrees, and preferably less than 45 degrees.

[0153] The distal termination portion 81 has a curved shape and a curved guide rail 83 is provided on this distal termination portion 81. This guide rail 83 is of a shape complementary to the anterior groove 5 of the implant 1, and has the same radius of curvature RC, to allow sliding guidance of the implant 1 as described later. The proximal termination portion 82 has a rectilinear shape.

[0154] The curvature of the distal termination portion 81 is such that this distal termination portion 81 extends, relative to the proximal termination portion 82, over an angular sector of the order of 90 degrees, at plus or minus 30 degrees. The distal termination portion 81 is in particular curved in an arc of a circle according to the radius of curvature RC given over such an angular sector of the order of 90 degrees.

[0155] The implantation pin 8 has a square or rectangular cross-section, over its entire length from its distal end 810 to its proximal end 820. The implantation pin 8 has: an anterior face 87 facing the primary support 7 in position; a posterior face 84 opposite the anterior face 87 and facing the implant 1 during its insertion; two opposite lateral faces 85, respectively an upper face and a lower face.

[0156] The guide rail 83 is produced in the form of two notches 830 formed in the respective lateral faces 85 at the distal termination portion 81. The guide rail 83 extends to the distal end 810, in other words the notches 830 extend to the distal end 810.

[0157] This guide rail 83 is curved in an arc of a circle according to the radius of curvature RC given over an angular sector of the order of 90 degrees, plus or minus 30 degrees.

[0158] Furthermore, the guide rail 83 is extended, from the distal termination portion 81, by a longitudinal rail 89 arranged on the proximal termination portion 82 and extending to the proximal end 820. This longitudinal rail 89 is a rectilinear rail and it is formed of two notches 890 arranged in the respective lateral faces 85 at the level of the proximal portion 82 and extending the notches 830.

[0159] Thus, the implantation pin 8 successively has a guide rail 83 arcuate along the distal termination portion 81, also arcuate, and a rectilinear longitudinal rail 89 along the proximal termination portion 82, also rectilinear.

[0160] Furthermore, the distal termination portion 81 has an arcuate slide 86 provided on the front face 87. This arcuate slide 86 extends to the distal end 810 over an angular sector of the order of 90 degrees, plus or minus 30 degrees.

[0161] This arcuate slide 86 extends in particular only over the distal termination portion 81 and stops at the start of the proximal termination portion 82. In a variant not illustrated, this arcuate slide 86 extends over the distal termination portion 81 and continues over the proximal termination portion 82 to the proximal end 820, for example if at the level of its manufacture the implantation pin 8 is first extruded then curved.

[0162] This arcuate slide 86 is of complementary shape to the arcuate rail 74 provided on the front face 712 of the distal part 71 of the primary support 7. This arcuate rail 74 and this arcuate slide 86 respectively form a first pivoting guide means and a second pivoting guide means suitable for cooperating together to guide the implantation pin 8 in pivoting during insertion of its distal termination portion 81 between the two spinous processes AE.

[0163] Also, in the fourth step of insertion of the implantation pin 8, as visible in Figure 14 , the implantation pin 8 is inserted with its proximal termination portion 82 more or less perpendicular to the primary support 7, and with its distal termination portion 81 which has its distal end 810 which points towards the front face 712 of the distal part 71 of the primary support 7, until the arcuate slide 86 engages with the arcuate rail 74.

[0164] Although not illustrated, it is advantageous if the implantation pin 8 is already pre-mounted on the primary support 7 in the non-tilted position (as seen in the Figure 14 ), so that the surgeon inserts the primary support 7 / holding handle 75 / implantation pin 8 assembly together (in a single insertion step), sliding everything onto the positioning pin 6 by acting on the holding handle 75.

[0165] However, if the surgeon needs to retract additional tissue in the axis of the lateral approach (axis AL of the implant 1) by means of, for example, a scraping tool such as a rasp, then in this case the implantation pin 8 would not be mounted directly on the primary support 7 to facilitate the retraction of the tissues.

[0166] In a fifth step illustrated in Figure 18 , the surgeon pivots (or tilts) the implantation pin 8 relative to the anchored and static primary support 7, as shown diagrammatically by the arrow PG, until the proximal termination portion 82 is pressed against the primary support 7 and the distal termination portion 81 extends partly between the two spinous processes AE.

[0167] As explained above, this pivoting of the implantation pin 8 is achieved thanks to the cooperation between the arcuate slide 86 and the arcuate rail 74. The pivoting of the implantation pin 8 is carried out at an angle of the order of 90 degrees.

[0168] The complementary dovetail shapes of the arcuate slide 86 and the arcuate rail 74 make it possible to maintain contact between the arcuate slide 86 and the arcuate rail 74 without risk of detachment of the distal termination portion 81 of the implantation pin 8 from the primary support 7.

[0169] In a sixth step illustrated in Figure 22 , the surgeon inserts an assembly comprising an ancillary holder 9 and an impactor 13; the ancillary holder 9 and the impactor 13 also being components of the insertion ancillary.

[0170] In reference to the Figures 19 et 20 , the ancillary holder 9 has an opposite distal part 91 and a proximal part 92, connected by two parallel rods 93.

[0171] The distal portion 91 is provided with support means shaped to support the implant 1, where these support means comprise two support elements 94, 95 having internal faces 940, 950 facing each other provided respectively with protuberances 941, 951.

[0172] These protrusions 941, 951 are shaped at least partially in an arc of a circle centered on the transverse axis AT and they form pivoting means complementary to the recesses 23 formed in the rear part 2 of the implant 1 to allow relative pivoting of the implant 1 on this implant holder 9 along the transverse axis AT.

[0173] As visible in Figure 21 , each protuberance 941, 951 is in the form of a protuberance in the form of an arc of a circle along an angular sector of less than 180 degrees, such as, for example and without limitation, an angular sector of between 20 and 175 degrees.

[0174] Furthermore, the support elements 94, 95 also have respective arcuate faces 943, 953, which border the respective internal faces 940, 950, and which are shaped in an arc of a circle centered on the transverse axis AT, where these two arcuate faces 943, 953 are designed to match the rounded shape of the rear end 20 of the implant 1 in order to be able to hold the implant 1 in place and also to be able to transmit a thrust onto the implant 1 during its insertion.

[0175] Thus, the protrusions 941, 951 carry the implant 1 which has its rear part 2 wedged between the internal faces 940, 950 with the protrusions 941, 951 engaged in the recesses 23, and which also has its rounded rear end 20 bearing against the arcuate faces 943, 953.

[0176] The two rods 93 have distal ends fixed to the respective support elements 94, 95. Furthermore, the two support elements 94, 95 are detachably attached to each other and, for this purpose, these support elements 94, 95 are provided with removable attachment means so that the two support elements 94, 95 are configurable between: an attached configuration (left on the Figure 21 ) to be able to support implant 1, and a detached configuration (right on the Figure 21 ) to be able to insert the implant 1 and thus remove the implant holder 9 as described later.

[0177] More precisely and as visible in Figure 21 , the removable attachment means are formed by an upper slide 942 and an upper rail 952 which are provided on the respective support elements 94, 95, or vice versa.

[0178] This upper slide 942 and this upper rail 952 are both arched and of complementary, dovetail shapes, and they extend between an anterior face and a posterior face of the distal part 91; the anterior face being turned towards the implantation pin 8 in situation and the posterior face, opposite the anterior face, being turned towards the spinous processes AE in situation.

[0179] This upper slide 942 and this upper rail 952 form pivoting guide means suitable for cooperating together to pivotally guide a support element 94 relative to the other support element 95, along the transverse axis AT.

[0180] In the attached configuration, the upper rail 952 is integrally nested or received within the upper slide 942 and the two support members 94, 95 are attached to each other and can support the implant 1 on their protrusions 941, 951.

[0181] Furthermore, it should be noted that the distal ends of the rods 93 have respective terminations 930 which protrude from the respective support elements 94, 95, and these terminations 930 have the function of coming to bear against the rear faces 241 of the respective locking fins 24 of the implant 1 (as visible in Figure 23 ), in order to hold implant 1 in place and also to be able to transmit a thrust onto implant 1 during its insertion.

[0182] To switch from the attached configuration to the detached configuration, it is sufficient to pivot one of the support elements 94, 95 around the transverse axis AT, which does not interfere with the implant 1, until the upper rail 952 is fully removed from the upper slide 942.

[0183] The anterior face of the distal portion 91 of the implant holder 9 has a groove 96 for partially receiving the implantation pin 8, as seen in Figure 23 This groove 96 being formed of two half-grooves facing each other provided in the respective support elements 94, 95.

[0184] The two rods 93 each have a circular cross-section, without this shape being limiting because each rod 93 can also have a rectangular, square, polygonal or other cross-section.

[0185] The two rods 93 have proximal ends, opposite their distal ends, which are removably attached to the proximal portion 92. This proximal portion 92 is in the form of a single-piece body which connects the proximal ends of the two rods 93 together, and this proximal portion 92 can be detached from the proximal ends of the two rods 93 when necessary, as described later.

[0186] The impactor 13 comprises an impaction rod 14 provided with a distal end fixed on the proximal part 92, between the proximal ends of the two rods 93. This impaction rod 14 is also provided with a distal end, opposite the distal end, and on which is fixed a handle 15 formed by two lateral wings allowing manual gripping of the impactor 13. The impactor 13 further comprises an impaction sleeve 16 mounted to slide around the impaction rod 14, between the handle 15 and the proximal part 92 of the implant holder 9.

[0187] The surgeon can thus exert, thanks to the impactor 13, a thrust on the implant holder 9, and therefore on the implant 1, in order to position the implant 1 between the two spinous processes AE, by exerting an impaction force, preferably repeated, which consists of holding the handle 15 with one hand and exerting with the other hand a sliding movement of the impaction sleeve 16 so that it impacts on the proximal part 92; this impaction force is then transmitted through the rods 93 to the support elements 94, 95, and finally through the terminations 930 and the arcuate faces 943, 953 to the implant 1.

[0188] At the beginning of the sixth step, the implant 1 is slid onto the longitudinal rail 89 of the implantation pin 8, along its posterior face 84, at its proximal end 820, engaging its anterior groove 5 through its front mouth 55 on the longitudinal rail 89, and with its front end 40 pointing towards the lateral part PL of vertebra VE.

[0189] More precisely, the retaining lips 53 of the anterior groove 5 are engaged inside the notches 890 formed in the respective lateral faces 85 of the implantation pin 8. The retaining lips 53 make it possible to maintain contact between the anterior groove 5 and the longitudinal rail 89 without risk of detachment of the implant 1 from the implantation pin 8.

[0190] It should be noted that, due to the arcuate shape of the front groove 5 and its retaining lips 53, the longitudinal rail 89 is wider than the arcuate guide rail 83. In other words, and as visible in Figure 17 , the notches 890 of the longitudinal rail 89 have a width LR, and they are extended by the notches 830 which have a width LC less than LR.

[0191] More precisely, and as visible on the Figure 17 , each notch 890 of the longitudinal rail 89 is delimited at the level of the rear face 84 by a notch edge 891 having a thickness ER. Similarly, and as visible on the Figure 17 , each notch 830 of the arcuate guide rail 83 is delimited at the level of the rear face 84 by a notch edge 831 having a thickness EC, where EC is greater than ER, and where LR + ER = LC + EC. Thus, each notch edge 891 is extended by the corresponding notch edge 831, with a widening from one towards the other.

[0192] It should be noted that the thickness ER is substantially equivalent to the intermediate height HI of the anterior groove 5 (see Figure 5 ), and the width LR is substantially equivalent to the overall height HG of the retaining lips 53 of the front groove 5 (see Figure 5 ), so that the implant 1 can slide along a rectilinear path along the longitudinal rail 89, with the retaining lips 53 of its anterior groove 5 sliding in the notches 890; the notch edges 891 sliding in the longitudinal gap defined by this intermediate height HI.

[0193] Furthermore, the thickness EC is substantially equivalent to the groove height HR of the anterior groove 5 (see Figure 5 ), and the width LC is substantially equivalent to the lip height HL of the retaining lips 53 of the front groove 5 (see Figure 5 ), so that the implant 1 can slide along an arcuate trajectory (centered on the center of curvature of the anterior face 11 of the implant 1 which merges with the center of curvature of the guide rail 83), with the retaining lips 53 of its anterior groove 5 which slide in the notches 830.

[0194] During the sixth step, the surgeon therefore pushes on the implant holder 9, by means of the impactor 13, to lower the implant holder 9 and the implant 1 along the longitudinal rail 89 and therefore the proximal termination portion 82 of the implantation pin 8, as shown diagrammatically by the arrow EN on the Figure 22 , until the front groove 5 reaches the arched guide rail 83.

[0195] It should be noted that the surgeon has previously rotated the gripping head 77 of the holding handle 75 by 90 degrees, after having pressed the unlocking button 771, so that the gripping head 77 can pass between the two rods 93, as seen in Figure 22 .

[0196] In a seventh step illustrated in Figures 25 à 28 , the surgeon continues to push on the implant holder 9, by means of the impactor 13, to slide the implant 1 along the arcuate guide rail 83 (facing the posterior face 84) of the distal termination portion 81, thus following a curvilinear trajectory which causes the implant 1 to pivot at an angle of the order of 90 degrees and to move towards the interspinous space between the two spinous processes AE, until the implant 1 reaches a final position between the two spinous processes AE, as visible in Figures 27 et 28 .

[0197] In this seventh step, the retaining lips 53 of the anterior groove 5 are engaged inside the notches 830, after passing through the notches 890. These retaining lips 53 make it possible to maintain contact between the anterior groove 5 and the guide rail 83 without risk of detachment of the implant 1 from the implantation pin 8.

[0198] During this curvilinear movement of the implant 1, this implant 1 pivots relative to the implant holder 9, thanks to the protuberances 941, 951 which cooperate with the recesses 23, and passes from an initial orientation substantially parallel to the primary support 7 to a final orientation substantially perpendicular to the primary support 7.

[0199] Thus, the implant holder 9 pivots (or tilts) concomitantly with the sliding of the implant 1, as shown diagrammatically by the arrow BA on the Figure 25 , with the proximal part 92 which passes over the holding handle 75. During this insertion, the tapered shape of the front part 4 of the implant 1 makes it possible to separate the two spinous processes AE, to bring its central part 3 between the two spinous processes AE.

[0200] Once implant 1 is in place, the surgeon can perform a control X-ray. If necessary, he can remove implant 1 by pulling on the impaction head 15 to raise the implant holder 9 and therefore implant 1. If the implant is correctly placed, the surgeon moves on to the eighth step described below.

[0201] In an eighth step illustrated in Figure 29 , the surgeon removes the impactor 13 from the implant holder 9, and to do this he detaches the proximal part 92 from the rods 93 and pulls on the handle 15 to remove this impactor 13.

[0202] In a ninth step illustrated in Figure 30 , the surgeon unlocks the implant holder 9 by moving its two support elements 94, 95 into the detached configuration.

[0203] To do this, the surgeon acts on the rods 93 to pivot one support element 94 relative to the other support element 95, as shown diagrammatically by the arrow MA on the Figures 30 And 31 , until the upper rail 952 is completely removed from the upper slide 942, as seen in Figure 31 .

[0204] Thus, the surgeon continues by completely removing the implant holder 9 which is detached from the implant 1, by pulling on a rod 93 which takes with it the support element 94 which is attached to it, and then by pulling on the other rod 93 which takes with it the other support element 95 which is attached to it.

[0205] In a tenth step illustrated in Figure 32 , the surgeon removes the implantation pin 8, and to do this he pivots (or tilts) the implantation pin 8 relative to the anchored and static primary support 7, as shown diagrammatically by the arrow BR, to move the proximal termination portion 82 away from the primary support 7 and cause the distal termination portion 81 to exit the anterior groove 5 (via its rear mouth 54) of the implant 1.

[0206] This pivoting of the implantation pin 8 is carried out at an angle of the order of 90 degrees, according to a rotation opposite to that carried out when it is placed on the primary support 7.

[0207] Thus, the surgeon continues by completely removing the implantation pin 8, then he pulls on the primary support 7, by means of the gripping head 77 of the holding handle 75, to remove the primary support 7, and finally the surgeon removes the positioning needle 6.

[0208] At this stage, only implant 1 is in place between the spinous processes AE, as illustrated in the Figures 8 à 10 , and the surgeon can complete the procedure, specifically by removing the retractor and closing the incision.

Claims

1. An interspinous vertebral implant (1) including an implant body (10) extending along a longitudinal axis (AL) and comprising successively along said longitudinal axis (AL): - a rear portion (2) having a rear end (20), - a central portion (3) shaped so as to extend between two spinous processes (AE) of two adjacent vertebrae (VE), said central portion (3) extending the rear portion (2), and - a front portion (4) extending the central portion (3), opposite to the rear portion (2), while tapering up to a front end (40) of streamlined shape, wherein said implant body (10) has: - an anterior face (11) intended to be directed towards the vertebrae (VE), - a guide channel formed in the implant body (10) from its rear end (20) up to its front end (40), said guide channel being shaped so as to receive at least one portion of an implantation spindle (8) of an implantation ancillary, said interspinous vertebral implant (1) being characterized in that the guide channel extends from the rear end (20) up to the front end (40) along a curvilinear direction, said guide channel being formed in the anterior face (11) so that said guide channel forms an anterior groove (5) of curvilinear shape and opening outside into said anterior face (11) of the implant body (10).

2. The interspinous vertebral implant (1) according to claim 1, wherein the anterior groove (5) is formed continuously in the anterior face (11) of the implant body (10) from the rear end (20) up to the front end (40), so as to continuously open into the anterior face (11).

3. The interspinous vertebral implant (1) according to claims 1 or 2, wherein the implant body (10) is not articulated, so that, in a rest position as well as in an implanted position, the anterior groove (5) is curvilinear shaped along the same curvature.

4. The interspinous vertebral implant (1) according to any one of the preceding claims, wherein the anterior groove (5) has a convex shape having a given radius of curvature (RC), with a center of curvature located facing a posterior face (12) of the implant body (10), opposite to the anterior face (11).

5. The interspinous vertebral implant (1) according to claim 4, wherein the anterior groove (5) is internally delimited by a bottom wall (50) offset in depth with respect to the anterior face (11), said bottom wall (50) having a convex shape having a given radius of curvature.

6. The interspinous vertebral implant (1) according to claim 5, wherein the anterior groove (5) is externally delimited by retaining lips (53) with a convex shape having the radius of curvature (RC), said retaining lips (53) being disposed facing the bottom wall (50) and extending facing each other so as to delimit a narrow space in comparison with the interior of the anterior groove (5).

7. The interspinous vertebral implant (1) according to any one of claims 1 to 6, wherein the rear portion (2) has pivot means (23) around a transverse axis (AT) extending transversely with respect to the longitudinal axis (AL) to enable a pivoting of said implant body (10) relative to complementary pivot means (941, 951) provided on an implant-holder (9) of the implantation ancillary.

8. The interspinous vertebral implant (1) according to any one of claims 1 to 7, wherein the rear portion (2) comprises, at an interface with the central portion (3), at least one blocking plate (24) projecting on a lower side of the rear portion (2) or on an upper side of the rear portion (2), opposite to the lower side.

9. An implantation ancillary, intended for guidance and positioning of an interspinous vertebral implant (1) according to any one of claims 1 to 8 between two spinous processes (AE) of two adjacent vertebrae (VE), said implantation ancillary comprising: - an implant-holder (9) having a distal portion (91) and a proximal portion (92) opposite to each other, said distal portion (91) being provided with support means (94, 95) shaped so as to support said interspinous vertebral implant (1); - an implantation spindle (8) having a distal end portion (81) which extends up to a free distal end (810) of tip shape, said distal end portion (81) having a curved shape and on which is provided a curved guide rail (83) with a shape complementary with an anterior groove (5) of the interspinous vertebral implant (1) to enable a sliding guidance of said interspinous vertebral implant (1) along a posterior face (84) of said distal end portion (81) by fitting of the guide rail (83) inside the anterior groove (5), said guide rail (83) extending up to the free distal end (810).

10. The implantation ancillary according to claim 9, wherein the distal end portion (81) of the implantation spindle (8) is curved in a circular arc over an angular sector comprised between 60 and 120 degrees.

11. The implantation ancillary according to claim 9 or 10, wherein the implantation spindle (8) comprises a proximal end portion (82) which extends the distal end portion (81) up to a free proximal end (820), and the guide rail (83) is prolonged, from the distal end portion (81), by a longitudinal rail (89) formed on the proximal end portion (82) up to the free proximal end (820).

12. The implantation ancillary according to claim 11, wherein at least one amongst the proximal end portion (82) and the longitudinal rail (89) is rectilinear.

13. The implantation ancillary according to any one of claims 9 to 12, wherein the distal end portion (81) of the implantation spindle (8) has two opposite lateral faces (85), respectively an upper face and a lower face, and the guide rail (83) is formed in the form of two notches (830) formed in said respective lateral faces (85).

14. The implantation ancillary according to any one of claims 9 to 13, wherein the distal end portion (81) of the implantation spindle (8) has an anterior face (87), opposite to the posterior face (84) along which the interspinous vertebral implant (1) slides, and on which is provided a first pivot guide means (86), and said implantation ancillary comprises a primary support (7) having a distal portion (71) on which are provided at least one anchoring relief (711) for anchorage, and a second pivot guide means (74) adapted to cooperate with the first pivot guide means (86) to pivotably guide said implantation spindle (8) during an insertion of its distal end portion (81).

15. The implantation ancillary according to claim 14, wherein the primary support (7) has a distal hole (73) opening into a distal face (710) of the distal portion (71) of the primary support (7), and the implantation ancillary comprises a positioning punch (6) provided with a tip-shaped distal end (61) intended for anchorage in a vertebra (VE), said positioning punch (6) being shaped so as to slidably guide the primary support (7) longitudinally by insertion of the positioning punch (6) inside the distal hole (73).

16. The implantation ancillary according to any one of claims 9 to 15, wherein the support means (94, 95) provided on the distal portion (91) of the implant-holder (9) comprise complementary pivot means (941, 951) shaped so as to cooperate with pivot means (23) of a rear portion (2) of the implant in order to enable a pivoting of said interspinous vertebral implant (1) around a transverse axis (AT).

17. The implantation ancillary according to any one of claims 9 to 16, wherein the implantation ancillary comprises an impactor (13) removably mounted on the proximal portion (92) of the implant-holder (9).