Interspinous vertebral implants and associated implant assisting devices

Abstract

The present invention relates to an interspinous implant (1), which comprises an implant body (10), which extends along a longitudinal axis (AL) and comprises in sequence: a rear portion (2) having a rear end (20), a central portion (3), which is shaped to extend between two spinous processes (AE) of two adjacent vertebrae (VE), the central portion (3) extending the rear portion (2), and a front portion (4), which extends the central portion (3) in the opposite direction to the rear portion (2) and tapers to a streamlined front end (40), wherein the implant body (10) has a front surface (11) intended to face the vertebra and a curved front groove (5) is formed in the front surface, which extends in a curved direction from the rear end (20) to the front end (40) to accommodate at least a portion of an implant tip of an implant auxiliary device.

Description

Technical Field

[0001] The present invention relates to the technical field of interspinous vertebral implants and auxiliary equipment for implanting such interspinous vertebral implants. Background Art

[0002] An interspinous vertebral implant is an implant intended to be positioned between the spinous processes of two adjacent vertebrae. Such an implant enables two adjacent spinous processes to be distracted relative to each other, that is to say to obtain a gap or spacing between them.

[0003] In particular, the present invention finds its use in the treatment of, for example, low back pain.

[0004] From the current state of the art, in particular from the document US 2012 / 0265246, an interspinous vertebral implant is known, comprising: an implant body, which includes a central portion for extending between two adjacent spinous processes; a front portion, which has a contour shape suitable for gradually moving the spinous processes away from the vertebrae and clearing a passage between the two vertebrae; and a guide channel, which is in the form of a straight guide hole formed through the implant body, which is open only at the front and rear of the implant body and is used to receive a guide pin.

[0005] Implanting the implant between two vertebrae requires surgical intervention. In the context of document US 2012 / 0265246, this intervention can be percutaneous or open and is performed via a lateral approach to the patient, although a dorsal approach is also contemplated, but with other models of interspinous vertebral implants. In any case, this intervention requires a lot of equipment to locate the exact location of the implant and clear the path to reach said location.

[0006] In fact, according to document US 2012 / 0265246, a guide pin is used, which is particularly used to fit into a linear guide hole formed in the implant to guide it during implantation, and two tools allow to clear tissue blocking access to the intervertebral space along the guide pin and partially or temporarily move the spinous process to better implant. The first tool has a head with a spiral spike shape or with a smooth contour shape and slides along the guide pin. The first tool is configured to temporarily move the spinous process when cutting the interspinous ligament.

[0007] Once the first gap is completed, a second tool is inserted along the guide pin, the second tool having the same overall shape as the first tool, but the second tool having a larger size in order to clear more tissue and prepare the implant site to a greater extent. It is described that several tools can be used in sequence until the site is completely cleared or has a large enough size to receive the implant. The implant is then placed in the cleared position by sliding along the guide pin.

[0008] This known and described method is limited because it requires several operations to place the implant and it requires a large number of tools prior to implantation. Furthermore, the surgical procedure via the lateral approach is usually performed under general anesthesia, which means a long and complicated surgical procedure with a large opening for the patient. Furthermore, due to the distance between the skin and the insertion area, the risk of malposition is considerable.

[0009] The teaching of document US8672977 also illustrates the current state of the art, and the document discloses a spinous intervertebral implant, which includes an articulated implant body, which is provided with a plurality of continuous and interconnected segments, so as to first be in a linear configuration (for its insertion) and then in a curved configuration (once implanted between two adjacent spinous processes). Therefore, at rest, the implant body is in a linear configuration and is passed through by a flexible contraction element, which passes through a passage in the form of aligned holes formed in the segment. At rest, these holes are aligned, and the passage is linear for introducing a flexible contraction element, which will be used to pull the segment at the front of the implant body so as to enable it to be converted from a linear configuration to a curved configuration.

[0010] However, the implant described in this document US8672977 has the disadvantage of being formed by an articulated body, which is converted from a linear configuration to a curved configuration (which gives the articulated body a reduced mechanical strength, and is necessarily less reliable), to ensure the dispersion of two adjacent spinous processes. In addition, when converted to a curved configuration from a linear configuration during the implantation of the implant body, there is a risk of material clogging between the segments of the implant body that are first spaced apart and then in contact, which may cause the patient to be squeezed and injured, and also hinder implantation.

[0011] One of the objects of the present invention is to get rid of articulating implant bodies by retaining the use of non-articulating implant bodies which are more reliable and less traumatic during their implantation.

[0012] It is also known from document US9101409 that an interspinous vertebral implant comprising an axisymmetric shell-type implant body is used, the implant body comprising a rear portion, a refined central portion and a streamlined front portion, wherein an axial hole is formed at the center of the implant so as to pass through it over its entire length; the axial hole is intended to slide the implant body along a linear guide rod via an outside approach with the aid of a push rod screwdriver (the push rod screwdriver is a hexagonal head fitted into a hexagonal aperture arranged at the rear of the axial hole), so that the implant is set in place by a lateral push and rotation combined motion, which is equivalent to an implantation by a threaded connection. It should be noted that the implant body also has a groove formed on half of the front portion, the entire central portion and half of the rear portion along the longitudinal direction; this groove is very thin and is used to give the implant flexibility so that the implant can shrink during its implantation, thereby reducing pressure on the patient.

[0013] As mentioned above, the implant of document US9101409 has drawbacks in terms of the complexity of the implantation process, which is essentially performed in an invisible and therefore unreliable manner, and in terms of the trauma to the patient, by means of the implant being implanted via a lateral approach, although the grooves may not be sufficient to reduce such stresses. Furthermore, its implantation by means of a threaded connection induces a torsion on the tissue and on the spinous processes, which may be a source of trauma.

[0014] It is also known from document US2012 / 0226313 that an interspinous vertebral implant is used that includes an implant body of an arched shape, the implant body being provided with a lateral slot for receiving two baffles, and being provided with a screw adapted to apply a clamping force on one of the two baffles at the rear; the two baffles are used to separate two adjacent spinous processes to the left and to the right, and the implant body is accommodated between the two spinous processes. However, this implant has limited mechanical reliability because the implant consists of three elements (an implant body and two baffles), which should be assembled together. The implant cooperates with an implant auxiliary device that includes a platform centered on a punch, and the platform is used as a support for other elements, and its main disadvantage is the instability of this platform during the entire operation, not to mention its traumatic appearance, because it involves several incisions, one through the implant body, and another one to two through two blocking screws. Other elements include a curved rod and a curved guide tube, which has a 90-degree arcuate shape, and the curved rod is fixed to a lever arm pivotably hinged on the platform, and the curved guide tube defines a curved passage and is fixed to a lever arm pivotably mounted on the platform. During implantation, once the platform is in position, although it lacks stability, the curved rod pivots on the platform so that its tip is positioned between two spinous processes, and then the curved guide tube also pivots on the platform, while being guided by the curved rod in the curved passage. Afterwards, remove the curved rod, and then the implant body can be pushed into the curved passage of the curved guide tube, until it is positioned between two spinous processes. Finally, two guide fingers will slide into two other curved tubes pivotably mounted on the platform as well. The implantation method described in the document US2012 / 0226313 has several disadvantages, including that the above-mentioned platform lacks stability, and the traumatic insertion of the curved rod and three curved tubes, because their 90-degree limiting shapes give them sizes, so that their implantation is necessarily traumatic, because their insertion involves long displacement. Summary of the invention

[0015] The present invention aims to overcome all or part of the above-mentioned disadvantages by providing an interspinous vertebral implant suitable for a simpler method of implementation via a primarily dorsal and marginal lateral approach, that is to say a method involving a dorsal approach but slightly eccentric with respect to the dorsal axis (or axis of the spine). In fact, the opening in the patient is made on the back in a portion that is as small as necessary, determined according to the insertion area of ​​the implant and according to the size of the implant and the size of the implant tool, which allows a reliable and accurate implantation of the implant under local anesthesia, thus eliminating the need for a laborious surgical intervention under general anesthesia, thus minimizing the risk of postoperative complications.

[0016] The present invention also proposes an implantation aid which is particularly suitable for the interspinous vertebral implant according to the present invention and which is suitable for a method of implantation between the spinous processes of two adjacent vertebrae (rather than between the vertebral endplates), which is simpler via a main dorsal approach.

[0017] To this end, an object of the present invention is an interspinous vertebral implant comprising an implant body extending along a longitudinal axis and comprising, in sequence along said longitudinal axis:

[0018] a rear portion having a rear end,

[0019] a central portion shaped to extend between two spinous processes of two adjacent vertebrae, said central portion extending the posterior portion, and

[0020] Extending the front portion of the center portion, which is opposite to the rear portion while tapering until the front end of the streamlined shape,

[0021] The implant body comprises:

[0022] Aim to point to the front surface of the vertebra,

[0023] a guide channel formed in the implant body from its rearward end to its forward end, the guide channel being shaped to receive at least a portion of an implant spindle of an implant assist device;

[0024] The interspinous vertebral implant is notable in that a guide channel extends from the rear end to the front end in a curvilinear direction, the guide channel being formed in the front surface so that the guide channel forms a curvilinear front groove and opens outwardly into the front surface of the implant body.

[0025] Thus, thanks to this anterior groove, this implant according to the invention allows receiving an implantation main axis that is curved in a predetermined manner. Thus, this implant according to the invention enables interventions to be carried out using a main dorsal approach, which is difficult or even impossible to conceive with the linear guide holes of the state of the art. In fact, its curvilinear shape, by virtue of a dorsal opening that is slightly eccentric with respect to the dorsal axis, enables an intuitive and progressive insertion between the vertebrae, thus facilitating direct implantation in a determined implantation area.

[0026] In the present invention, the following terms are defined:

[0027] The front part should be understood as the part of the implant body which is intended to be inserted into the patient's body first;

[0028] The rear portion is to be understood as the portion of the implant body which is intended to penetrate at least into the patient's body;

[0029] The streamlined shape is understood to mean the shape of the front end which becomes thinner from the rear to the front in the longitudinal direction;

[0030] Curvilinear direction, it should be understood that the direction through the passage follows a curve rather than a straight line, such as a curve in an arc of a circle on a given radius of curvature;

[0031] anterior surface, referring to the patient’s anatomy to represent the surface pointing toward the vertebrae;

[0032] posterior surface, with reference to the patient's anatomy to mean the surface on the side of the skin on the back pointing opposite to the vertebrae;

[0033] inferior surface, referring to the patient's anatomy to represent the surface of the spinous process pointing toward the inferior vertebra (bottom vertebra);

[0034] superior surface, referring to the patient's anatomy to represent the surface of the spinous process pointing toward the superior vertebra (top vertebra);

[0035] The implant according to the invention may comprise one or more of the following features considered alone or in combination.

[0036] According to one feature, the front groove is formed continuously (in other words, without any interruption or break) in the front surface of the implant body from the rear end to the front end so as to be continuously arranged in the front surface.

[0037] According to another feature, the implant body is not articulated, so that, in the rest position (before implantation) and in the implanted position (once implanted between the two spinous processes), the anterior groove is of a curvilinear shape shaped along a curve of the same curvature.

[0038] According to another feature, the front groove has a convex shape with a given radius of curvature, the center of curvature being positioned facing the rear surface of the implant body opposite the front surface.

[0039] A convex shape corresponding to the direction of the curve in the arc of a circle is advantageous because it enables the implant to be transformed from a vertical orientation to a horizontal orientation throughout its insertion along a flexible and seamless guiding path of the implant.

[0040] According to one possibility, the front surface has a convex shape having a radius of curvature.

[0041] Guiding of the implant can therefore also be accomplished by following the front surface which is likewise curved.

[0042] According to another possibility, the front recess is delimited internally by a bottom wall offset in depth relative to the front surface, said bottom wall having a convex shape with a given radius of curvature.

[0043] Guiding of the implant can therefore also be accomplished by following this bottom wall which is likewise curved.

[0044] According to a variant, the bottom wall and the front surface have the same centre of curvature and the radius of curvature of the bottom wall is smaller than the radius of curvature of the front surface.

[0045] According to another possibility, the front groove is delimited externally by retaining flanges with a convex shape having a radius of curvature, said retaining flanges being arranged facing the bottom wall and extending facing each other so as to delimit a space that is narrower than the interior of the front groove.

[0046] The front groove therefore has a "C"-shaped cross-section with a retaining flange at the end of the "C", which will ensure the function of retaining the implant, in other words, the function of being able to keep the implant on the implant spindle without any risk of detaching from the implant spindle during insertion.

[0047] In a particular embodiment, the radius of curvature is comprised between 20 and 300 millimeters.

[0048] This radius of curvature provides the advantage of facilitating surgical intervention using a primary dorsal approach (dorsal opening slightly eccentric relative to the dorsal axis) and limiting the size of the incision.

[0049] In a particular embodiment, the rear portion has pivot means about a transverse axis extending transversely with respect to the longitudinal axis, so that the implant body can be pivoted relative to complementary pivot means provided on an implant holder of the implantation aid.

[0050] Thus, these pivoting means will enable the implant to be easily pivoted during its insertion, which is carried out along an insertion path having at least one curvilinear component, which will facilitate the insertion since the implant will be connected and retained by the implant holder along the entire curvilinear component of the path.

[0051] According to one feature, the rear portion has two opposite side surfaces, an upper surface and a lower surface, and the pivot device is arranged on the opposite side surfaces in the form of a recess or a protrusion, the shape of which is at least partially determined by an arc of a circle centered on the transverse axis.

[0052] Thus, the pivot means operate by form fitting and the complementary pivot means provided on the implant holder have a complementary shape for coupling by form fitting, which enables a relative pivoting between the implant and the implant holder.

[0053] In a particular embodiment, the front portion includes facets directly connected to each other by sharp edges, the front end converging and tapering to a point toward the front end.

[0054] The sharp edge provides the advantage of allowing easy puncture and cutting of the interspinous ligament and clearing a pathway for the implant.

[0055] According to a variant, the tip and the facets of the front part define a volume of truncated cone, pyramid or trapezoidal shape. This shape offers the advantage of facilitating the puncture of the ligament area while remaining compact.

[0056] In a variant of the invention, the sharp edge can be obtained by using a simple machined profile.

[0057] In a variant of the invention, at least one and preferably all of the sharp edges are straight, which enables clean piercing of the ligament area.

[0058] In an advantageous embodiment, the rear portion comprises, at the junction with the central portion, at least one baffle which projects on the lower side of the rear portion or on the upper side of the rear portion opposite the lower side.

[0059] Furthermore, the or each baffle extends at the front of the rear portion and thus at the rear of the central portion between the rear portion and the central portion, and it forms a plate adapted to abut against the spinous processes so as to stop the implant in its insertion path and ensure accurate positioning between the two spinous processes. Thus, during implantation of the implant, the or each baffle prevents the implant from moving out of the interspinous space by pressing each baffle against an adjacent spinous process so as to avoid inadvertent removal of the implant.

[0060] Advantageously, the rear portion comprises, at the junction with the central portion, a baffle protruding on the lower side of the rear portion and another baffle protruding on the upper side of the rear portion.

[0061] According to a variant, the two baffles are coplanar.

[0062] According to another variant, the two baffles are identical and symmetrical with respect to a median plane containing the longitudinal axis.

[0063] According to one possibility, at least one baffle extends from the associated side of the rear portion in a plane orthogonal to the longitudinal axis or in a plane inclined relative to the longitudinal axis at an angle comprised between 60 and 120 degrees.

[0064] Thus, when the or each stop extends from the posterior portion in a plane substantially perpendicular to the longitudinal axis of the implant body, it is naturally anchored to the respective spinous process.

[0065] According to another possibility, at least one flap is fixed or hinged to the rear part.

[0066] An advantage of a fixed stop is a simple design and a cheap implant body.

[0067] In the case of a hinged baffle, the baffle can be moved between at least one deployed position and a stowed position, in which the baffle extends along an axis substantially perpendicular to the longitudinal axis of the implant body, and in the stowed position, the baffle preferably abuts the involved side of the rear portion and extends along an axis substantially parallel to the longitudinal axis of the implant body.

[0068] According to another possibility, at least one baffle has a front face pointing in the front direction, and at least one anchoring protrusion is provided on the front face, the anchoring protrusion being configured to be anchorable on the spinous process, such as an anchoring protrusion in the form of a spike.

[0069] The anterior face is intended to face one of the spinous processes and the anchoring projection will confer a stable anchoring in this spinous process in the final position of the implant.

[0070] According to a variant, at least one baffle has several anchoring projections.

[0071] According to another variant, at least one spike extends along an axis substantially parallel to the longitudinal axis of the implant.

[0072] According to another variant, the front face of at least one abutment is coated with an osteointegrative material promoting adhesion between the bone and the implant body, such as, for example, a porous material.

[0073] In a particular embodiment, the central portion has two opposite side surfaces, respectively an upper surface and a lower surface, which are concave so as to define two recessed side surfaces suitable for fitting between two spinous processes.

[0074] It should be noted that the upper surface of the central portion is intended to bear on the spinous processes of the vertebra below, while the lower surface of the central portion is intended to bear on the spinous processes of the vertebra below. Thus, this concave shape of the two faces allows conformity to the bases of the two spinous processes and also promotes a slight elastic deformation suitable for ensuring a soft distraction between adjacent spinous processes relative to each other and thus reducing the lordosis at this level.

[0075] According to a variation, the implant body is made of at least one biocompatible sterilizable material. As a non-limiting example, the implant body can be made of a material selected from titanium, titanium-based alloys, steel, biocompatible plastic materials (such as polyetheretherketone (PEEK), polymethylmethacrylate (PMMA) etc.).

[0076] The present invention also relates to an implantation auxiliary device for guiding and positioning an interspinous vertebral implant according to the present invention between two spinous processes of two adjacent vertebrae, the implantation auxiliary device comprising:

[0077] an implant holder having a distal portion and a proximal portion opposite to each other, the distal portion being provided with a support means shaped to support the interspinous vertebral implant;

[0078] An implant spindle having a distal portion extending to a free and pointed distal end, the distal portion having a curved shape and provided with a curved guide track, the shape of which is complementary to the front groove of the interspinous vertebral implant so that the interspinous vertebral implant can be slidably guided along the rear surface of the distal portion by assembling the guide track in the front groove, the guide track extending to the free distal end.

[0079] Thus, the interspinous vertebral implant will be able to be guided along an at least partially curved path by the guide track of the curved implant spindle, which enables an intuitive and progressive insertion between the two spinous processes of the vertebra. In other words, by its anterior groove, the implant will be able to position itself and slide on the curved implant spindle, thereby enabling the use of a main dorsal approach, along a curved path (made possible by the shape of the curved implant spindle) and by intervening with the aid of a dorsal opening slightly eccentric to the dorsal axis, thereby facilitating direct implantation in a determined implantation area.

[0080] In other words, thanks to this implantation aid according to the invention, the implant spindle is guided in a curved manner at its distal portion, which enables surgical intervention using a primary dorsal approach. In addition, due to its anterior position relative to the implant, the implant spindle is used to protect the neural elements present in the vertebral channel.

[0081] It should be noted that, in the context of the present invention, the implant spindle forms an elongated, in particular curved, body terminating in a free and pointed distal end so as to be able to be inserted into the patient's body by clearing a path through the tissue until it is in the proper position facing the interspinous space between two spinous processes, which is the conventional function of the spindle in the surgical field. In addition, the implant spindle has the peculiarity previously described, namely the presence of a guide track on which the interspinous vertebral implant is slidably guided; this sliding must be carried out on the implant spindle (in other words, the implant is outside the implant spindle), and not inside the implant spindle, because in the surgical field, it is common practice for the spindle not to form a channel or tube in which the implant can slide.

[0082] It should also be noted that the guide track provided on the implant spindle has the function of guiding the interspinous vertebral implant along a curved implantation path, but it must also have the function of preventing or limiting lateral displacement of the implant in order to avoid it from deviating from the guide track.

[0083] It is advantageous to position the curved distal portion of the implant spindle as far forward as possible at the level of the interspinous space, since the optimal position of the implant at the end of the intervention corresponds to the front of the interspinous space, i.e. the area where the bone is widest and strongest. Therefore, the direction of the curve of the guide groove is selected so that the implant spindle has a satisfactory angle of attack for entering the interspinous space.

[0084] In the present invention, the term "proximal" refers to the part or end closest to the surgeon's hand during implantation of the implant, and the term "distal" refers to the part or end farthest from the surgeon's hand during implantation, or in other words, the part or end closest to the patient during intervention.

[0085] According to one feature, the implant spindle is solid and it does not form a tube or channel.

[0086] According to one possibility, the distal end portion of the implant spindle is bent in an arc over an angular sector comprised between 60 and 120 degrees.

[0087] In a particular embodiment, the distal portion of the implant spindle is curved in an arc at a radius of curvature comprised between 20 and 300 millimeters.

[0088] This radius of curvature provides the advantage of facilitating surgical intervention using a primary dorsal approach and limiting the size of the incision.

[0089] According to another possibility, the implant spindle comprises a proximal portion extending the distal portion to a free proximal end, and the guide track is extended from the distal portion to the proximal end by a longitudinal track formed on the proximal portion.

[0090] Thus, the interspinous process vertebral implant can slide on the longitudinal track at the proximal level and thereby slide in the direction of the curved distal portion in order to slide into the curved guide track and follow a curvilinear path.

[0091] Obviously, in the context of the present invention, the guide track and the longitudinal track can form a continuous track, and the interspinous vertebral implant can be assembled from the proximal end to the distal end.

[0092] In other words, the guide track and the longitudinal track are arranged together on the implant main shaft, which has the function of guiding the interspinous vertebral implant along a complete implantation path that is straight and then curved, but the guide track and the longitudinal track must also have the function of preventing or limiting lateral displacement of the implant so as to avoid it from disengaging from the guide track and the longitudinal track.

[0093] According to one possibility, at least one of the proximal portion and the longitudinal track is rectilinear, in other words, the proximal portion is rectilinear and / or the longitudinal track is rectilinear.

[0094] Thus, the interspinous vertebral implant will follow an insertion path that first has a linear component (sliding on the longitudinal track) and then finally has a curvilinear component (sliding on the curved guide track), which enables the implant to transition from a vertical orientation (outside the patient's body) to a horizontal orientation (inside the patient's interspinous space).

[0095] According to one feature, the guide track is formed on at least one outer surface of the distal portion of the implant spindle.

[0096] In other words, the guide track is formed on the exterior of the implant shaft for sliding the implant on the implant shaft (rather than inside a tube or channel).

[0097] According to another feature, the free and pointed distal end of the implant spindle has a tip angle less than or equal to 90 degrees, and preferably less than or equal to 60 degrees, and possibly less than or equal to 45 degrees.

[0098] In fact, the small tip angle facilitates the penetration of the implantation spindle into the tissue.

[0099] In a particular embodiment, the distal end portion of the implant spindle has two opposite side surfaces, respectively an upper surface and a lower surface, and the guide track is formed in the form of two recesses formed in said respective side surfaces.

[0100] Such recesses are suitable for receiving the previously described retaining flanges, respectively, and thus allow stable and reliable guidance over the entire distance.

[0101] According to one feature, the distal portion of the implant main shaft has a front surface, which is opposite to the rear surface along which the implant slides, and a first pivot guide device is provided on the front surface, and the implant auxiliary device includes a main support member having a distal portion and a second pivot guide device, on which at least one anchoring protrusion for anchoring is provided, and the second pivot guide device is suitable for cooperating with the first pivot guide device to pivotably guide the implant main shaft during the insertion of its distal portion between two spinous processes.

[0102] Thus, the main support will be anchored in the vertebra in the region located in the midplane passing between the two spinous processes and will then be used to guide the implant spindle to fit its distal portion between the two spinous processes using a pivoting or tilting movement of the implant spindle.

[0103] In a particular embodiment, the first pivot guide and the second pivot guide comprise an arcuate track and an arcuate slide, respectively, with complementary shapes.

[0104] According to a variant, the first pivot guide and the second pivot guide are shaped so as to pivotably guide the implantation spindle along a pivot angle comprised between 60 and 120 degrees, in particular in the range of 90 degrees.

[0105] According to another feature, the main support has a proximal portion coupled to a grip handle having a gripping head.

[0106] The main function of such a gripping handle is to enable the surgeon to grip and therefore allow the surgeon to set and grip the main support in order to anchor it in the vertebrae, in particular by applying thrusts and, if necessary, impacts on the gripping head, preferably repeatedly, to impact the main support.

[0107] According to a variant, the gripping handle is distinct from the main support and is fixed to it, or it is made integrally with the main support.

[0108] According to another feature, the main support member has a distal hole leading to the distal side of the distal part of the main support member, and the implantation auxiliary device includes a positioning punch having a distal end with a tip shape for anchoring in the vertebra, and the shape of the positioning punch is determined to longitudinally slidably guide the main support member by inserting the positioning punch into the distal hole.

[0109] The positioning punch is thus anchored in the vertebra at a precise point determined by the surgeon and is substantially located in the mid-plane passing between the two spinous processes and it will be used to guide the main support to position it in the desired area.

[0110] In a particular embodiment, the support means provided on the distal portion of the implant holder comprises complementary pivot means shaped to cooperate with the pivot means of the posterior portion of the interspinous vertebral implant so as to enable the vertebral implant to pivot about the transverse axis.

[0111] According to one possibility, the support means comprise two support elements having inner surfaces facing each other and respectively provided with recesses or projections at least partially shaped as arcs of a circle centred on the transverse axis and forming complementary pivoting means.

[0112] Thus, the interspinous process vertebral implant is wedged between the inner surfaces of two corresponding support elements while being pivotally movable between the two inner surfaces.

[0113] Furthermore, the pivoting means are operated by form fitting, and the complementary pivoting means provided on the implant holder have complementary shapes for coupling by form fitting, which enables relative pivoting between the implant and the implant holder.

[0114] According to another possibility, the two support elements are detachably attached to each other and for this purpose are provided with removable attachment means such that the two support elements can be configured between an attached configuration allowing support of the interspinous vertebral implant and a detached configuration allowing release of the interspinous vertebral implant from the implant holder.

[0115] In this manner, once the interspinous vertebral implant is in place between the two spinous processes, all that is required is to separate the two support elements from one another to allow the interspinous vertebral implant to be released, thereby removing the implant holder while leaving the interspinous vertebral implant in place.

[0116] According to one possibility, the removable attachment means are formed by an upper slide and an upper rail which are arranged on the corresponding supporting element.

[0117] According to another possibility, the upper sliding portion and the upper rail are both arched and have complementary shapes and extend between the front surface and the rear surface of the distal part of the implant holder to form a pivot guide device that is suitable for fitting together so as to pivotally guide the support element around a transverse axis relative to another support element.

[0118] Thus, the separation between the two supporting elements is accomplished by pivoting without obstructing the implant.

[0119] According to another possibility, the distal part and the proximal part of the implant holder are connected by two rods having a distal end fastened to the corresponding support element and a proximal end opposite thereto which is removably fastened to the proximal part.

[0120] Advantageously, the distal end of the rod has a corresponding tip protruding from a corresponding support element so as to be able to bear against a corresponding stop of the implant.

[0121] In certain embodiments, the implant assist device includes an impactor removably mounted on a proximal portion of the implant holder.

[0122] According to one feature, the impactor comprises an impact rod having a distal end fastened to a proximal portion of the implant holder and a proximal end opposite the distal end and to which a handle is fastened.

[0123] According to another feature, the impactor further includes an impact sleeve slidably mounted about the impact rod, the impact sleeve being located between the handle and the proximal portion of the implant holder. BRIEF DESCRIPTION OF THE DRAWINGS

[0124] Other features and advantages of the invention will become apparent on reading the following detailed description of a non-limiting example of embodiment with reference to the attached schematic drawings, in which:

[0125] Figure 1 is a perspective view of the rear side of an example of an interspinous process vertebral implant according to the present invention;

[0126] Figure 2 yes Figure 1 Anterior view of the implant (front side);

[0127] Figure 3 yes Figure 1 An illustration of the bottom of the implant (inner surface side);

[0128] Figure 4 yes Figure 1 A perspective view of the front side of the implant;

[0129] Figure 5 yes Figure 1 Dorsal view (posterior side) of the implant;

[0130] Figure 6 yes Figure 1 Illustration of the posterior side of the implant;

[0131] Figure 7 yes Figure 1 Illustration of the anterior side of the implant;

[0132] Figure 8 yes Figure 1 Perspective view of the implant in place between the two spinous processes (dorsal and posterior view);

[0133] Fig. 9 yes Figure 1 Perspective views of the implant in place between the two spinous processes (anterior and posterior views);

[0134] Fig.10 yes Figure 1 An illustration of the posterior side of the implant in proper position between the two spinous processes; and

[0135] Fig.11 is a diagrammatic representation of a first step of inserting a positioning punch of an implantation aid according to the present invention;

[0136] Fig.12 is a diagrammatic representation of a second step of inserting a main support member of an implantation assist device according to the present invention;

[0137] Fig.13 Based on two different viewpoints Fig.12 a perspective view of a distal portion of a main support member;

[0138] Fig.14 is a diagrammatic representation of a third step of coupling a grip handle to a main support and a fourth step of inserting an implant spindle of an implantation aid according to the present invention;

[0139] Fig.15 yes Fig.14 A separate perspective view of the grip handle;

[0140] Fig.16 is an enlarged perspective view of the distal portion of the main support member. Fig.14 During the fourth step the distal end portion of the implanted spindle is guided onto the distal portion;

[0141] Fig.17 Based on several viewpoints and the whole (left view) or part (three right views) Fig.14 A separate perspective view of the implant spindle;

[0142] Fig.18 is an illustration of a fifth step of pivoting (or tilting) the implant spindle relative to a static main support;

[0143] Fig.19 is a perspective view of an implant assist device kit according to the present invention, which includes a support Figure 1 An auxiliary device holder for an implant, and further comprising an impactor mounted on the implant holder;

[0144] Fig. 20 yes Fig.19 A perspective view of an implant holder alone;

[0145] Fig.21 yes Fig.19 A perspective view of a distal portion of an implant holder of , with its two support elements in an attached configuration (to the left) and a detached configuration (to the right);

[0146] Fig. 22 Yes Insert Fig.19 Illustration of the sixth step of the auxiliary device holder and impactor kit, the auxiliary device holder supports Figure 1 implants;

[0147] Fig.23 is an enlarged perspective view of the distal portion of the main support and the distal end portion of the implant main shaft, Fig.19 The implant carried by the implant holder slides on the implant spindle;

[0148] Fig.24 is an enlarged perspective view of the distal portion of the main support and the distal end portion of the implant main shaft, Fig.19 The implant carried by the implant holder slides on the implant spindle;

[0149] Fig.25 It is a push Figure 1An illustration of the beginning of the seventh step of the implant of the present invention, wherein the implant is slid on the implant spindle in the direction of the interspinous space between two spinous processes;

[0150] Fig.26 is Fig.25 an enlarged perspective view of the implant sliding on the implant spindle at the beginning of the seventh step;

[0151] Fig. 27 It is a push Figure 1 FIG. 1 is an illustration of the end of the seventh step of an implant of FIG. 1 , wherein the implant is slid onto the implant spindle and thereafter positioned between the two spinous processes;

[0152] Fig.28 is Fig. 27 An enlarged perspective view of the implant placed on the spindle at the end of the seventh step;

[0153] Fig.29 is an illustration of an eighth step of removing the impactor from the implant holder;

[0154] Fig.30 is an illustration of a ninth step of unlocking the implant holder by converting its two support ends into a separated configuration;

[0155] Fig.31 is Fig.30 An enlarged perspective view of an implant and an implant holder during a ninth step of the present invention;

[0156] Fig.32 is Fig.30 Illustration of the tenth step of removing the implant spindle after removing the implant holder after the ninth step. DETAILED DESCRIPTION

[0157] For the sake of simplicity, identical elements or elements which fulfill the same function are provided with the same reference signs for different exemplary embodiments.

[0158] Now refer to Figures 1 to 7 An implant 1 according to the invention is described. The implant 1 according to the invention is an interspinous vertebral implant comprising an implant body 10 made of at least one biocompatible material. More specifically, the implant 1 is formed integrally and solely from the implant body 10 .

[0159] The implant body 10 extends along a longitudinal axis AL and comprises, in order along the longitudinal axis AL:

[0160] a rear portion 2 having a rear end 20,

[0161] The central portion 3 is shaped to be located between the two spinous processes AE of the two adjacent vertebrae VE (eg Figures 8 to 10), the central portion 3 extends between the rear portion 2, and

[0162] A front portion 4 extending the central portion 3, which is opposite to the rear portion 3 and tapers gradually to a front end 40 of streamlined shape,

[0163] The central portion 3 thus joins the rear portion 2 to the front portion 4 and extends between the rear portion 2 and the front portion 4 .

[0164] It should be noted that, compared with front part 2, central part 3 can have some elasticity, makes central part 3 bend on its whole insertion path, particularly bends on the whole curve part of this insertion path.Once insert, this flexibility of implant body 1 allows to keep the movability between two adjacent vertebrae within a given range.This elasticity of central part 3 helps to make implant body 10 have two " zones " with different rigidity / flexibility, and this elasticity of this central part can for example be modified by geometry (for example, grid type structure) and / or obtain by using different materials.

[0165] The rear portion 2 has the general shape of a semi-disc, the rear end 20 of which is circular, or more precisely semi-cylindrical, centered on a transverse axis AT perpendicular to the longitudinal axis AL.

[0166] The rear part 2 has two opposite side surfaces 21, 22, respectively an upper surface 21 and a lower surface 22, with a general shape of a semi-disc and on which means for pivoting about the transverse axis AT are provided. For this purpose, the pivoting means are provided in the form of a recess 23 formed on the respective side surface 21, 22 and having a shape at least partially determined by an arc of a circle centered on the transverse axis AT. Figure 3 As shown, the recess 23 is in the form of a circular arc-shaped recess over an angular sector less than 180°, such as, for example but not limited to, an angular sector comprised between 20 and 175 degrees.

[0167] As explained later, these recesses 23 are intended to cooperate with complementary protrusions 941 , 951 provided on the implant holder 9 , so that the implant body 10 can be relatively pivoted on the implant holder 9 about the transverse axis AT.

[0168] At the junction between the rear portion 2 and the central portion 3, the rear portion 2 includes a baffle 24 protruding on the lower side of the rear portion 2 (on the same side as the lower surface 22) and another baffle 24 protruding on the upper side of the rear portion 2 (on the same side as the upper surface 21).

[0169] The two baffles 24 are symmetrical with respect to a midplane PM including the longitudinal axis AL and orthogonal to the transverse axis AT, and one baffle 24 extends perpendicularly to the lower surface 22 , while the other baffle 24 extends substantially perpendicularly to the upper surface 21 .

[0170] The baffles 24 extend coplanarly in a plane substantially orthogonal to the longitudinal axis AL, or more generally in a plane inclined relative to the longitudinal axis AL at an angle comprised between 60 and 120 degrees. In general, the implant body 10 is symmetrical relative to the median plane PM.

[0171] The two baffles 24 protrude outwards relative to the corresponding side surfaces 21, 22 and relative to the central part 3. The two baffles 24 are fastened and integral with the implant body 10. In a variant not shown, the baffles 24 are hinged on the corresponding side surfaces 21, 22 or the baffles 24 are removably mounted on the side surfaces 21, 22.

[0172] Each of the two baffles 24 has a front face 240 directed toward the front end 40 and a rear face 241 opposite the front face 240 and directed toward the rear end 20 .

[0173] On each front face 240 of the two baffles 24, several spikes 25 are provided to form anchoring protrusions, which are configured to be anchored on the spinous process AE. These spikes 25 extend in a direction parallel to the longitudinal axis AL. In turn, the rear faces 241 of the two baffles 24 are smooth.

[0174] The central part 3 has two opposite side surfaces 31, 32, respectively an upper surface 31 and a lower surface 32, and the central part is concave so as to define two concave side surfaces 31, 32 suitable for fitting between the two spinous processes AE. In other words, the central part 3 is thinned at its center to conform to the shape of the spinous processes AE. The two baffles 24 protrude outwardly relative to the corresponding side surfaces 31, 32.

[0175] The front portion 4 has a streamlined shape suitable for piercing the ligament area and, for this purpose, comprises flat facets directly connected to each other by sharp straight edges that converge towards the front end 40 and taper to a tip.

[0176] The implant body 10 also has an anterior surface 11 for pointing toward the vertebra VE and a posterior surface 12 opposite to the anterior surface 11 .

[0177] The front surface 11 has a convex shape with a radius of curvature RC comprised between 20 and 300 mm, the center of its curvature being positioned facing the rear surface 12 of the implant body 10. In turn, the rear surface 12 has a convex shape at the level of the central portion 3 and a flat facet shape at the level of the front portion 4.

[0178] The implant body 10 also has a front groove 5, which is formed in the front surface 11 and completely passes through the implant body 10 from the rear end 20 to the front end 40 thereof so as to form a guide channel as described below, the shape of which is determined to receive at least a portion of the implant spindle 8 of the implant auxiliary device described below.

[0179] like Figure 4 and 7 As clearly shown, the front groove 5 is continuously formed in the front surface 11 of the implant body 10 from the rear end 20 to the front end 40 , so as to be continuously arranged in the front surface 11 .

[0180] The front groove 5 has a convex shape having a radius of curvature RC, and thus extends along a curved direction of an arc shape from the rear end 20 to the front end 40. The front groove 5 extends in the midplane PM and is symmetrical with respect to the midplane PM.

[0181] Although some flexibility of the implant body 10 is contemplated, the implant body 10 does not form an articulated body in any way, in other words, the implant body 10 is not articulated so that in the rest position ( Figures 1 to 7 shown) and implantation location ( Figures 8 to 10 and Figures 27 to 32 The front groove 5 has a curved shape with the same curvature.

[0182] like Figure 5 As shown, the front groove 5 is internally delimited by a bottom wall 50 that is offset in depth by a given depth PR relative to the front surface, the given depth being constant from the rear end 20 to the front end 40 .

[0183] The bottom wall 50 has a convex shape with a center of curvature coinciding with that of the front surface 11 and having a radius of curvature RP (not shown) smaller than the radius of curvature RC of the front surface 11. The depth PR is measured along a radial direction passing through the center of curvature, so RC=RP+PR.

[0184] The front groove 5 is internally delimited by two side walls 51 and 52 that are parallel to the midplane PM and are in the shape of a circular arc. The distance between the two side walls 51 and 52 defines the width LA of the front groove 5.

[0185] The front groove 5 is delimited externally by retaining flanges 53 having a convex shape with a radius of curvature RC at the level of the front surface 11. These retaining flanges 53 protrude from the corresponding side walls 51, 52, moreover they are arranged facing the bottom wall 50 and they extend facing each other so as to delimit a space that is narrow compared to the interior of the front groove 5. In other words, the spacing EC between two retaining flanges 53 is smaller than the width LA of the front groove 5. These retaining flanges 53 are integral with the front surface 11 into which the front groove 5 opens.

[0186] like Figure 5 As shown, each retaining flange 53 has a flange thickness or height HL measured along the radial direction passing through the center of curvature. Therefore, the front groove 5 has a groove height HR between the retaining flange 53 and the bottom wall 50, which is also measured along the radial direction passing through the center of curvature, so that: PR = HR + HL.

[0187] Furthermore, the shape of the previous groove 5 is such that:

[0188] Considering a first guide and a second guide parallel to the longitudinal axis AL, wherein the first guide passes through the lowest point of the bottom wall 50 (substantially at the middle position between the rear end 20 and the front end 40), and the second guide passes through the highest point of the retaining flange 53 (at the level of the rear end 20 or the front end 40), the front groove 5 has a non-zero intermediate height HI corresponding to the distance measured between the first guide and the second guide along a direction orthogonal to the longitudinal axis AL and the transverse axis AT, as Figure 5 as shown; and

[0189] Considering a third guide parallel to the longitudinal axis AL, wherein the third guide passes through the lowest point of the retaining flange (substantially midway between the rear end 20 and the front end 40), the retaining flange 53 has an overall height HG corresponding to the distance measured between the second guide and the third guide along a direction orthogonal to the longitudinal axis AL and the transverse axis AT, as shown in FIG. Figure 5 shown.

[0190] This configuration advantageously allows the implant 1 to be slid along a longitudinal (in other words straight) path on a longitudinal track 89 (described later) and then along a curved or arcuate path on a curved guide track 83 (described later).

[0191] The front groove 5 has a rear mouth 54 opening to the rear end 20 and a front mouth 55 opening to the front end 40 at two corresponding ends thereof.

[0192] refer to Figures 11 to 32The following description relates to an implantation aid for guiding and positioning an implant 1 between two spinous processes AE of adjacent vertebrae VE, and to a method for implanting an implant 1 with the aid of such an implantation aid.

[0193] The implantation aid is in the form of a kit comprising several components of different functions which cooperate together to enable the implantation of the implant 1 using a primary dorsal approach. These different components of the implantation aid will be described step by step through their use in the implementation of the implantation method.

[0194] In advance, and refer to Fig.11 , the surgeon determines a reference point located in the lateral portion PL of the vertebra VE, which is at a lateral distance DL relative to the axis AC (also called the dorsal axis) of the spine CV, such lateral distance DL being determined in advance before the surgery, for example, between 5 and 70 mm. This reference point is located substantially in the middle plane between the two spinous processes AE. Therefore, the implantation method is called a primary dorsal approach method insofar as it involves a dorsal approach that is slightly eccentric to the dorsal axis at a lateral distance DL.

[0195] This previous step of determining the reference points can be done in advance, for example by using a pre-operative scanner which also allows the width of the target interspinous space to be measured and the size of the implant 1 to be selected according to this width.

[0196] The surgeon then makes an incision above the reference point at a lateral distance DL relative to the axis AC of the spine CV.

[0197] exist Fig.11 In the first step shown, the surgeon moves aside different elements such as tissue, muscles, ligaments etc. with the aid of spacers (not shown) and he inserts a positioning punch 6 , which forms part of the implantation aid, via a dorsal approach until it is anchored at a reference point.

[0198] The positioning punch 6 is an elongated straight rod having a pointed distal end 61. The positioning punch 6 has a rectangular cross section, which is not limited because the positioning punch 6 can also have a circular, square, polygonal cross section or other cross sections. The pointed distal end 61 is anchored on a reference point in the lateral part PL of the vertebra PE.

[0199] The positioning punch 6 also has a proximal end 62 opposite to the distal end 61, and the positioning punch 6 is long enough to allow the proximal end 62 to protrude from the patient's back.

[0200] exist Fig.12 In the second step shown, the surgeon inserts the main support 7 , which is another component of the implantation aid, by sliding it over the positioning punch 6 , as indicated by arrows GU.

[0201] The main support 7 is in the form of a tubular elongated body having a distal portion 71 and a proximal portion 72 opposite to each other. The distal portion 71 has a distal surface 710 which, when in position, points toward the vertebrae, from which several spikes 711 protrude, which form anchoring projections configured to be anchored on the lateral portion PL of the vertebrae VE. The proximal portion 72 has a proximal surface 720 pointing outwards, which is opposite to the distal surface 710.

[0202] The main support member 7 has a distal hole 73 (eg, Fig.13 ), and also has a proximal hole 730 leading to its proximal side 720 (as shown Fig.12 The two holes 73, 730 can be composed of two holes that are closed or connected to each other.

[0203] The main support 7 is longer than the positioning punch 6, and the distal hole 73 is substantially longer than the positioning punch 6. Therefore, the positioning punch 6 is formed to be longitudinally slidably guided to the main support 7 by inserting the positioning punch 6 into the distal hole 73.

[0204] The main support 7 is introduced from the outside at the level of the proximal end 62 by being assembled at the level of the proximal face 720 and then slides along the positioning punch 6 (as indicated by the arrow GU) until the spike 711 comes into contact with the lateral part PL of the vertebra VE.

[0205] The distal portion 71 of the main support 7 widens in the direction of the distal surface 710 and it has an anterior face 712 pointing in the direction of the spinous processes AE, which has a curved and concave shape, from which a concave arcuate track 74 with a dovetail-shaped cross section protrudes.

[0206] exist Fig.12 In the third step shown, the surgeon couples the gripping handle 75 to the proximal portion 72 of the main support 7 , and more specifically, fixes the gripping handle 75 to the proximal surface 720 of the main support 7 .

[0207] It should be noted that in a preferred variation, during the above-mentioned second step, the gripping handle 75 can already be connected to the main support 7, so that before the main support 7 is inserted, the gripping handle 75 is already fastened to the main support 7 so that the surgeon can correctly grip the main support 7 / gripping handle 75 kit and slide it on the positioning punch 6.

[0208] The gripping handle 7 comprises a body 76 which is extended on one side by a gripping head 77 and on the other side by a mounting pin 78 adapted to be fitted into a proximal hole 730 of the main support 7 for coupling. The gripping head 77 is provided with two side wings 770 which enable the gripping handle 7 to be manually gripped.

[0209] Advantageously, the gripping head 77 is mounted so as to be movable and rotated 90 degrees on the body 76, and the locking system allows the gripping head 77 to be locked in the first position and the second position after the rotation of 90 degrees. In addition, the locking system comprises an unlocking button 771 located on the gripping head 77, which is in the middle and in line with the body 70 between the two side wings 770 and which allows the rotation of the gripping head 77 to be unlocked to switch from the first position to the second position and vice versa.

[0210] Afterwards, holding the handle 75, the surgeon will exert thrust on the main support 7 by exerting a thrust on the gripping head 77 and possibly an impact force (preferably repeatedly) to hit the main support 7 in order to anchor it in the lateral part PL of the vertebra VE.

[0211] exist Fig.14 In the fourth step shown, the surgeon inserts an implantation spindle 8, which is another component of the implantation auxiliary device. As will be explained later, this implantation spindle 8 can be pre-installed on the main support 7, so that the surgeon inserts the kit of the main support 7 / holding handle 75 / implantation spindle 8 together in a separate step.

[0212] The implant spindle 8 has a distal portion 81 extending to a free, tip-shaped distal end 810 , and a proximal portion 82 extending the distal portion 81 to a free proximal end 820 .

[0213] like Fig.16 and 17 As shown, the tip-shaped free distal end 810 has a tip angle less than 90 degrees, and preferably less than 45 degrees.

[0214] The distal portion 81 has a curved shape, and a curved guide track is provided on the distal portion 81. The guide track 83 has a shape complementary to the front groove 5 of the implant 1 and has the same radius of curvature RC to achieve sliding guidance of the implant 1, as described below. The proximal portion 82 has a straight shape.

[0215] The curvature of the distal portion 81 is such that the distal portion 81 extends over an angle sector in the range of 90 degrees, more or less 30 degrees relative to the proximal portion 82. In particular, the distal portion 81 is curved into an arc at a given radius of curvature RC over such an angle sector in the range of 90 degrees.

[0216] The implantation spindle 8 has a square or rectangular cross section over the entire length starting from its distal end 810 to its proximal end 820. The implantation spindle 8 has:

[0217] a front surface 87 which, when in position, points toward the main support 7;

[0218] a rear surface 84 which is opposite the front surface 87 and which is directed towards the implant 1 during its insertion;

[0219] The two side surfaces 85 facing each other are an upper surface and a lower surface respectively.

[0220] The guide track 83 is made in the form of two notches 830 formed in corresponding side surfaces 85 at the level of the distal portion 81. The guide track 83 extends to the distal end 810, in other words, the notches 830 extend to the distal end 810.

[0221] The guide rail 83 is curved into an arc at a given radius of curvature RC over an angular sector in the range of 90 degrees, more or less 30 degrees.

[0222] Furthermore, the guide track 83 is extended from the distal portion 81 by a longitudinal track 89 formed on the proximal portion 82 and extending to the proximal end 820. This longitudinal track 89 is a straight track, and it is formed by two notches 890 formed in the corresponding side surfaces 85 at the level of the proximal portion 82 and extending the notch 830.

[0223] Thus, the implant spindle 8 has in turn an arcuate guide track 83 along the distal portion 81 (also arcuate) and a rectilinear longitudinal track 89 along the proximal portion 82 (also rectilinear).

[0224] Furthermore, the distal portion 81 has an arcuate sliding portion 86 formed on the front surface 87. The arcuate sliding portion 86 extends to the distal end 810 over an angular sector in the range of 90 degrees, more or less 30 degrees.

[0225] In particular, the arcuate slide 86 extends only over the distal portion 81 and stops at the beginning of the proximal portion 82. In a variant not shown, the arcuate slide 86 extends over the distal portion 81 and over the proximal portion 82 to the proximal end 820, for example if during its manufacture the implant spindle 8 is first squeezed and then bent.

[0226] The arcuate slide 86 has a shape complementary to the arcuate track 74 provided on the front face 712 of the distal portion 71 of the main support 7. The arcuate slide 86 and the arcuate track 74 respectively form a first pivot guide and a second pivot guide, which are adapted to cooperate together so as to pivotably guide the implant spindle 8 during the insertion of the distal end portion 81 of the implant spindle 8 between the two spinous processes AE.

[0227] Furthermore, in the fourth step of inserting the implant spindle 8, as shown in FIG. Fig.14 As shown, the implant main shaft 8 is inserted until the arched sliding portion 86 engages with the arched track 74, wherein the proximal portion 82 of the implant main shaft is substantially perpendicular to the main support member 7, and the distal portion 81 of the implant main shaft has a distal end 810 pointing to the front face 712 of the distal portion 71 of the main support member 7.

[0228] Although not shown, it is advantageous if the implant spindle 8 is already pre-mounted on the main support 7 in a non-inclined position (e.g. Fig.14 As shown), the surgeon slides the entire slide over the positioning punch 6 by moving the gripping handle 75, thereby inserting the main support 7 / gripping handle 75 / implantation main shaft 8 kit together (in a single introduction step).

[0229] However, if the surgeon has to move more tissue along the axis of the lateral approach (axis AL of implant 1 ), for example with the aid of a scraping tool such as a scraper, then in this case the implant spindle 8 will not be mounted directly on the main support 7 to facilitate tissue spreading.

[0230] exist Fig.18 In the fifth step shown, the surgeon pivots (or tilts) the implant spindle 8 relative to the anchored and static main support 7, as indicated by arrow PG, until the proximal portion 82 presses against the main support 7 and the distal portion 81 extends partially between the two spinous processes AE.

[0231] As described above, due to the cooperation between the arcuate slide 86 and the arcuate track 74, the pivoting of the implantation main shaft 8 is achieved. The pivoting of the implantation main shaft 8 is performed at an angle within a range of 90 degrees.

[0232] The dovetail-shaped complementary shape of the arcuate slide 86 and the arcuate track 74 allows the contact between the arcuate slide 86 and the arcuate track 74 to be maintained without any risk of the distal end portion 81 of the implanted main shaft 8 being detached from the main support 7 .

[0233] exist Fig. 22In the sixth step shown, the surgeon inserts a kit comprising an auxiliary device holder 9 and an impactor 13; the auxiliary device holder 9 and the impactor 13 are also components of the implantation auxiliary device.

[0234] refer to Fig.19 and 20 The auxiliary device holder 9 has a distal portion 91 and a proximal portion 92 opposite to each other, and the distal portion and the proximal portion are connected by two parallel rods 93.

[0235] The distal portion 91 is provided with support means which are shaped to support the implant 1 , wherein these support means comprise two support elements 94 , 95 which have inner surfaces 940 , 950 facing each other and which are provided with protrusions 941 , 951 respectively.

[0236] The shape of these protrusions 941, 951 is at least partially determined as an arc centered on the transverse axis AT, and they form a pivot device complementary to the recess 23 formed in the posterior part 2 of the implant 1 so that the implant 1 can pivot relatively on the implant holder 9 around the transverse axis AT.

[0237] like Fig.21 As shown, each protrusion 941 , 951 is in the form of a circular arc-shaped protrusion over an angular sector less than 180 degrees, such as, for example but not limited to, an angular sector comprised between 20 and 175 degrees.

[0238] In addition, the support elements 94, 95 also have corresponding arched surfaces 943, 953, which are adjacent to the corresponding inner surfaces 940, 950 and are formed as circular arcs centered on the transverse axis AT, wherein these two arched surfaces 943, 953 are intended to conform to the circular shape of the rear end 20 of the implant 1 so as to allow the implant 1 to be maintained in an appropriate position and also allow thrust to be transmitted on the implant during insertion of the implant 1.

[0239] Thus, the protrusions 941 , 951 carry an implant 1 having a rear portion 2 wedged between the inner surfaces 940 , 950 , the protrusions 941 , 951 fitting in the recess 23 , and the implant also having a rounded rear end 20 bearing against the arcuate surfaces 943 , 953 .

[0240] The two rods 93 have distal ends fastened to the corresponding 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 can be configured between the following configurations:

[0241] Attachment structure ( Fig.21to the left side) to allow support for the implant 1, and

[0242] Separation structure ( Fig.21 to the right side) to allow release of the implant 1 and thus removal of the implant holder 9, as described below.

[0243] More specifically, and as Fig.21 As shown, the removable attachment means are formed by an upper slide 942 and an upper track 952 provided on the corresponding support element 94, 95, or vice versa.

[0244] The upper sliding portion 942 and the upper rail 952 are both arched and have complementary dovetail shapes, and they extend between the front surface and the rear surface of the distal portion 91; the front surface points to the implant spinous process AE when in the proper position, and the rear surface opposite to the front surface points to the spinous process AE when in the proper position.

[0245] The upper slide 942 and the upper track 952 form a pivot guide adapted to cooperate together in order to pivotally guide the support element 94 relative to the other support element 95 about the transverse axis AT.

[0246] In the attached configuration, the upper rail 952 is integrally nested or received within the upper slide 942 , and the two support elements 94 , 95 are attached to each other and are able to support the implant 1 on their protrusions 941 , 951 .

[0247] Furthermore, it should be noted that the distal end of the rod 93 has a corresponding tip 930 protruding from the corresponding support element 94, 95, and these tips 930 are intended to bear against the rear face 241 (eg, Fig.23 ), so as to hold the implant 1 in place and also allow thrust to be transmitted on the implant 1 during insertion.

[0248] To switch from the attached configuration to the detached configuration, all that is required is to pivot one of the support elements 94 , 95 about the transverse axis AT, which does not hinder the implant 1 until the upper rail 952 is completely disengaged from the upper slide 942 .

[0249] like Fig.23 As shown, the front surface of the distal portion 91 of the implant holder 9 has a groove 96 to partially receive the implant spindle 8. The groove 96 is formed by two half grooves facing each other and formed in the corresponding support elements 94,95.

[0250] Each of the two rods 93 has a circular cross-section, but the shape is not limited because each rod 93 may also have a rectangular, square, polygonal cross-section, or other shaped cross-section.

[0251] The two rods 93 have proximal ends opposite to their distal ends, which are removably fastened to the proximal portion 92. The proximal portion 92 is in an integral form, which connects the proximal ends of the two rods 93 to each other, and the proximal portion 92 can be separated from the proximal ends of the two rods 93 when necessary, as described below.

[0252] The impactor 13 comprises an impact rod 14 provided with a distal end fastened to a proximal portion 92 between the proximal ends of two rods 93. The impact rod 14 is also provided with a proximal end, opposite to the distal end, and to which a handle 15 formed by two flanks is fastened, enabling manual gripping of the impactor 13. The impactor 13 further comprises an impact sleeve 16 slidably mounted around the impact rod 14, the impact sleeve being located between the handle 15 and the proximal portion 92 of the implant holder 9.

[0253] Thus, thanks to the impactor 13, the surgeon is able to apply a thrust on the implant holder 9 and thereby on the implant 1 so as to position the implant 1 between the two spinous processes AE by applying a thrust force (preferably repeatedly), which comprises holding the handle 15 with one hand and applying a sliding movement of the impact handle 16 with the other hand so that it impacts the proximal portion 92; the impact force is then transmitted through the rod 93 to the support elements 94, 95 and ultimately to the implant through the end 930 and the arched surfaces 943, 953.

[0254] At the beginning of the sixth step, the implant 1 is engaged on the longitudinal track 89 of the implant main shaft 8 along the posterior surface 84 of the implant main shaft at the level of the proximal end 820 of the implant main shaft, and at the same time, the front groove 5 of the implant is engaged on the longitudinal track 89 of the implant main shaft through the front mouth 55 of the implant, and the front end 40 of the implant points in the direction of the lateral part PL of the vertebra VE.

[0255] More specifically, the retaining flange 53 of the front groove 5 fits in a notch 890 formed in the corresponding side surface 85 of the implant spindle 8. The retaining flange 53 allows the contact between the front groove 5 and the longitudinal track 89 to be maintained without any risk of the implant 1 being separated from the implant spindle 8.

[0256] It should be noted that due to the arcuate shape of the front groove 5 and its retaining flange 53, the longitudinal track 86 is wider than the arcuate guide track 83. In other words, Fig.17 As shown, the notches 890 of the longitudinal rail 89 have a width LR, and they are extended by notches 830 having a width LC that is less than LR.

[0257] More specifically, if Fig.17 As shown, each notch 890 of the longitudinal rail 89 is delimited at the level of the rear surface 84 by a notch edge 891 having a thickness ER. Fig.17 As shown, each notch 830 of the arcuate guide rail 83 is delimited at the level of the rear surface 84 by a notch edge 831 having a thickness EC, wherein EC is greater than ER, and wherein LR+ER=LC+EC. Thus, each notch edge 891 is extended by the corresponding notch edge 831, wherein one notch edge widens toward the other notch edge.

[0258] It should be noted that the thickness ER is substantially equal to the middle height HI of the front groove 5 (see Figure 5 ), and the width LR is substantially equal to the overall height HG of the retaining flange 53 of the front groove 5 (see Figure 5 ) so that the implant 1 can slide along a straight path along the longitudinal track 89, and the retaining flange 53 of the front groove 5 of the implant slides in the recess 890; the recess edge 891 in turn slides in the longitudinal gap defined by the intermediate height HI.

[0259] Furthermore, the thickness EC is substantially equal to the groove height HR of the front groove 5 (see Figure 5 ), and the width LC is substantially equal to the flange height HL of the retaining flange 53 of the front groove 5 (see Figure 5 ) so that the implant 1 can slide along an arched path (centered on the center of curvature of the front surface 11 of the implant 1, which coincides with the center of curvature of the guide track 83), and the retaining flange 53 of the front groove 5 of the implant slides in the recess 830.

[0260] Therefore, during the sixth step, the surgeon pushes the implant holder 9 with the aid of the impactor 13 so that the implant holder 9 and the implant 1 descend along the longitudinal track 89 and thus along the proximal portion 82 of the implant spindle 8, as shown in FIG. Fig. 22 As shown by the arrow EN in the figure, until the front groove 5 reaches the arcuate guide track 83.

[0261] It should be noted that the surgeon has previously pivoted the gripping head 77 of the gripping handle 75 by 90 degrees, after pressing the unlocking button 771, so that the gripping head 77 can pass between the two rods 93, as shown in FIG. Fig. 22 shown.

[0262] exist Figures 25 to 28 In the seventh step shown, the surgeon continues to push the implant holder 9 with the aid of the impactor 13 so that the implant 1 slides along the arcuate guide track 83 (facing the rear surface 84) of the distal portion 81 and thus slides along a curved path, which causes the implant 1 to pivot an angle within a 90-degree range and move in the direction of the interspinous space between the two spinous processes AE until the implant 1 reaches the final position between the two spinous processes AE, as shown in FIG. Fig. 27 and 28 shown.

[0263] In this seventh step, the retaining flanges 53 of the front groove 5 are fitted in the recesses 830 after passing through the notches 890. These retaining flanges 53 allow the contact between the front groove 5 and the guide rail 83 to be maintained without any risk of the implant 1 being separated from the implant spindle 8.

[0264] During this curvilinear displacement of the implant 1 , due to the protrusions 941 , 951 cooperating with the recess 23 , the implant 1 pivots relative to the implant holder 9 and transitions from an initial position substantially parallel to the main support 7 to a final position substantially perpendicular thereto.

[0265] Therefore, the implant holder 9 pivots (or tilts) as the implant 1 slides. Fig.25 As shown by arrow BA in , the proximal portion 92 passes over the grip handle 75. During this insertion, the streamlined shape of the front portion 4 of the implant 1 allows the two spinous processes AE to be expanded to fit the central portion 3 of the implant between the two spinous processes AE.

[0266] Once the implant 1 is in place, the surgeon can perform a control radio. If necessary, the surgeon can remove the implant 1 by pulling the impact head 15 to lift the implant holder 9 and the implant 1. If the implant is correctly placed, the surgeon proceeds to the eighth step described below.

[0267] exist Fig.29 In an eighth step shown, the surgeon removes the impactor 13 from the implant holder 9 and, for this purpose, he detaches the proximal portion 92 of the rod 93 and he pulls the handle 15 to remove the impactor 13 .

[0268] exist Fig.30 In a ninth step shown, the surgeon unlocks the implant holder 9 by converting its two support elements 94, 95 into a separated configuration.

[0269] For this purpose, the surgeon pivots the support element 94 on the rod 93 relative to the other support element 95, as shown in FIG. Fig.30 and 31 As shown by the arrow MA in FIG. 1 , until the upper rail 952 is completely separated from the upper sliding portion 942, as shown in FIG. Fig.31 shown.

[0270] The surgeon therefore proceeds to completely remove the implant holder 9 detached from the implant 1 , pulling one rod 93 carrying a support element 94 attached thereto and then the other rod 93 carrying a further support element 95 attached thereto.

[0271] exist Fig.32 In the tenth step shown, the surgeon removes the implant spindle 8 and, for this purpose, he pivots (or tilts) the implant spindle 8 relative to the anchored and static main support 7, as indicated by the arrow BR, so that the proximal portion 82 moves away from the main support 7 and the distal portion 81 is disengaged from the front groove 5 of the implant 1 (through the rear mouth 54 of the implant).

[0272] This pivoting of the implantation spindle 8 is performed at an angle within a range of 90 degrees, and its rotation direction is opposite to the rotation direction when implanted on the main support 7.

[0273] Therefore, the surgeon proceeds to completely remove the implant spindle 8 , then he pulls the main support 7 by means of the gripping head 77 of the gripping handle 75 to remove the main support 7 , and finally the surgeon removes the positioning punch 6 .

[0274] At this level, only implant 1 is in place between the spinous processes AE, as shown in Figures 8 to 10 as shown, and the surgeon is able to complete the intervention, in particular by removing the dilator and closing the incision.

Claims

1. An interspinous vertebral implant (1), comprising an implant body (10), the implant body extending along a longitudinal axis (AL) and comprising, in sequence along the longitudinal axis (AL): a rear portion (2), the rear portion having a rear end (20), a central portion (3) shaped to extend between two spinous processes (AE) of two adjacent vertebrae (VE), said central portion (3) extending said posterior portion (2), and a front portion (4) extending opposite the rear portion (2) from the central portion (3) while tapering to a front end (40) of streamlined shape, Wherein, the implant body (10) comprises: an anterior surface (11) intended to point toward the vertebra (VE), a guide channel formed in the implant body (10) from a rear end (20) of the implant body to a front end (40) of the implant body, the guide channel being shaped to receive at least a portion of an implant spindle (8) of an implant assisting device; The interspinous vertebral implant (1) is characterized in that the guide channel extends from the rear end (20) to the front end (40) along a curved direction, and the guide channel is formed in the front surface (11), so that the guide channel forms a front groove (5) having a curved shape and opens outward in the front surface (11) of the implant body (10), wherein the front groove (5) is continuously formed in the front surface (11) of the implant body (10) from the rear end (20) to the front end (40), thereby continuously opening in the front surface (11), and wherein the implant body (10) is not hinged, so that in the static position and the implanted position, the front groove (5) is a curved shape shaped along the same curvature.

2. The interspinous vertebral implant (1) according to claim 1, wherein: The front groove (5) has a convex shape with a given radius of curvature (RC), the center of curvature being positioned facing the rear surface (12) of the implant body (10) opposite to the front surface (11).

3. The interspinous vertebral implant (1) according to claim 2, wherein: The front surface (11) has a convex shape having the radius of curvature (RC).

4. The interspinous vertebral implant (1) according to claim 2, wherein: The front recess (5) is internally delimited by a bottom wall (50) offset in depth relative to the front surface (11), the bottom wall (50) having a convex shape with a given radius of curvature.

5. The interspinous vertebral implant (1) according to claim 4, wherein: The front groove (5) is externally delimited by a retaining flange (53) having a convex shape with the radius of curvature (RC), the retaining flanges (53) being arranged facing the bottom wall (50) and extending facing each other so as to delimit a space narrower than the interior of the front groove (5).

6. The interspinous vertebral implant (1) according to claim 2, wherein: The radius of curvature (RC) is comprised between 20 and 300 mm.

7. The interspinous vertebral implant (1) according to claim 1, wherein: The rear portion (2) has pivot means about a transverse axis (AT) extending transversely relative to the longitudinal axis (AL) to enable the implant body (10) to be pivoted relative to complementary pivot means provided on an implant holder (9) of the implantation aid.

8. The interspinous vertebral implant (1) according to claim 7, wherein: The rear portion (2) has two opposite side surfaces, an upper surface and a lower surface, and the pivoting device is arranged on the opposite side surfaces in the form of a recess (23) or a protrusion, the shape of which is at least partially a circular arc centered on the transverse axis (AT).

9. The interspinous vertebral implant (1) according to claim 1, wherein: The front portion (4) comprises facets directly connected to each other by sharp edges which converge towards the front end (40) and taper to a point.

10. The interspinous vertebral implant (1) according to claim 1, wherein: The rear portion (2) comprises at least one baffle (24) at the junction with the central portion (3), the baffle protruding on the lower side of the rear portion (2) or on the upper side of the rear portion (2) opposite to the lower side.

11. The interspinous vertebral implant (1) according to claim 10, wherein: The rear portion (2) comprises, at the junction with the central portion (3), a baffle (24) protruding on the lower side of the rear portion (2) and another baffle (24) protruding on the upper side of the rear portion (2).

12. The interspinous vertebral implant (1) according to claim 10, wherein: The at least one baffle (24) extends from the associated side of the rear portion (2) in a plane orthogonal to the longitudinal axis (AL) or inclined relative to the longitudinal axis (AL) at an angle comprised between 60 and 120 degrees.

13. The interspinous vertebral implant (1) according to claim 10, wherein: The at least one baffle (24) has a front surface (240) pointing in the direction of the front end (40), and at least one anchoring protrusion configured to be anchored on the spinous process (AE) is provided on the front surface.

14. The interspinous vertebral implant (1) according to claim 1, wherein: Said central portion (3) has two opposite lateral surfaces, respectively an upper surface and a lower surface, said opposite lateral surfaces being concave so as to define two recessed lateral surfaces suitable for fitting between the two spinous processes (AE).

15. The interspinous vertebral implant (1) according to claim 13, wherein the anchoring projections are in the form of spikes.

Images