INTERSPINOUS IMPLANT AND ASSOCIATED IMPLANTATION ANCILLARY

Abstract

An interspinous implant includes an implant body extending along a longitudinal axis and having, in succession: a rear part having a rear end, and a central part shaped to extend between two spinous processes of two adjacent vertebrae, the central part extending the rear part. The implant further includes a front part extending the central part, in the opposite direction from the rear part, and tapering down to a front end of streamlined shape. The implant body has an anterior face intended to face toward the vertebrae and in which there is formed an anterior groove of curvilinear shape, extending from the rear end as far as the front end in a curvilinear direction, to accept at least a portion of an implantation prong of an implantation ancillary.

Claims

1. An interspinous vertebral implant including 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 so as 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 to the rear portion, while tapering up to a front end of streamlined shape, wherein said implant body has: an anterior face intended to be directed towards the vertebrae, a guide channel formed in the implant body from its rear end up to its front end, said guide channel being shaped so as to receive at least one portion of an implantation spindle of an implantation ancillary; said interspinous vertebral implant being characterized in that the guide channel extends from the rear end up to the front end along a curvilinear direction, said guide channel being formed in the anterior face so that said guide channel forms an anterior groove of curvilinear shape and opening outside into said anterior face of the implant body.

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

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

4. The interspinous vertebral implant according to claim 1, wherein the anterior groove has a convex shape having a given radius of curvature, with a center of curvature located facing a posterior face of the implant body, opposite to the anterior face.

5. The interspinous vertebral implant according to claim 4, wherein the anterior face has a convex shape having the radius of curvature.

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

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

8. The interspinous vertebral implant according to claim 4, wherein the radius of curvature is comprised between 20 and 300 millimeters.

9. The interspinous vertebral implant according to claim 1, wherein the rear portion has pivot means around a transverse axis extending transversely with respect to the longitudinal axis to enable a pivoting of said implant body relative to complementary pivot means provided on an implant-holder of the implantation ancillary.

10. The interspinous vertebral implant according to claim 9, wherein the rear portion has two opposite lateral faces, respectively an upper face and a lower face, and the pivot means are provided on said opposite lateral faces in the form of recesses or of protrusions shaped at least partially in a circular arc centered on the transverse axis.

11. The interspinous vertebral implant according to claim 1, wherein the front portion comprises facets directly connected to each other by sharp edges converging towards the front end tapering into a tip.

12. The interspinous vertebral implant according to claim 1, wherein the rear portion comprises, at an interface with the central portion, at least one blocking plate projecting on a lower side of the rear portion or on an upper side of the rear portion, opposite to the lower side.

13. The interspinous vertebral implant according to claim 12, wherein the rear portion comprises, at the interface with the central portion, a blocking plate projecting on the lower side of the rear portion and another blocking plate projecting on the upper side of the rear portion.

14. The interspinous vertebral implant according to claim 12, wherein the at least one blocking plate extends from the concerned side of the rear portion in a plane orthogonal to the longitudinal axis or inclined with respect to the longitudinal axis by an angle comprised between 60 and 120 degrees.

15. The interspinous vertebral implant according to claim 12, wherein the at least one blocking plate has a front face directed in the direction of the front end and on which is provided at least one anchoring relief configured to enable anchorage on a spinous process, such as an anchoring relief in the form of a spike.

16. The interspinous vertebral implant according to claim 1, wherein the central portion has two opposite lateral faces, respectively an upper face and a lower face, which are concave so as to define two recessed lateral faces adapted to fit between the two spinous processes.

17. An implantation ancillary, intended for guidance and positioning of an interspinous vertebral implant according to claim 1 between two spinous processes of two adjacent vertebrae, said implantation ancillary comprising: an implant-holder having a distal portion and a proximal portion opposite to each other, said distal portion being provided with support means shaped so as to support said interspinous vertebral implant; and an implantation spindle having a distal end portion which extends up to a free distal end of tip shape, said distal end portion having a curved shape and on which is provided a curved guide rail with a shape complementary with an anterior groove of the interspinous vertebral implant to enable a sliding guidance of said interspinous vertebral implant along a posterior face of said distal end portion by fitting of the guide rail inside the anterior groove, said guide rail extending up to the free distal end.

18. The implantation ancillary according to claim 17, wherein the implantation spindle is solid.

19. The implantation ancillary according to claim 17, wherein the distal end portion of the implantation spindle is curved in a circular arc over an angular sector comprised between 60 and 120 degrees.

20. The implantation ancillary according to claim 17, wherein the distal end portion of the implantation spindle is curved in a circular arc over a radius of curvature comprised between 20 and 300 millimeters.

21. The implantation ancillary according to claim 17, wherein the implantation spindle comprises a proximal end portion which extends the distal end portion up to a free proximal end, and the guide rail is prolonged, from the distal end portion, by a longitudinal rail formed on the proximal end portion up to the free proximal end.

22. The implantation ancillary according to claim 21, wherein at least one amongst the proximal end portion and the longitudinal rail is rectilinear.

23. The implantation ancillary according to claim 17, wherein the guide rail is formed on at least one outer face of the distal end portion of the implantation spindle.

24. The implantation ancillary according to claim 17, wherein the distal end portion of the implantation spindle 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.

25. The implantation ancillary according to claim 17, wherein the distal end portion of the implantation spindle has an anterior face, opposite to the posterior face along which the interspinous vertebral implant slides, and on which is provided a first pivot guide means, and said implantation ancillary comprises a primary support having a distal portion on which are provided at least one anchoring relief for anchorage, and a second pivot guide means adapted to cooperate with the first pivot guide means to pivotably guide said implantation spindle during an insertion of its distal end portion.

26. The implantation ancillary according to claim 25, wherein the first pivot guide means and the second pivot guide means respectively comprise an arcuate rail and an arcuate slide with complementary shapes.

27. The implantation ancillary according to claim 25, wherein the first pivot guide means and the second pivot guide means are shaped so as to pivotably guide the implantation spindle over a pivot angle comprised between 60 and 120 degrees.

28. The implantation ancillary according to claim 25, wherein the primary support has a proximal portion coupled to a holding grip provided with a gripping head.

29. The implantation ancillary according to claim 25, wherein the primary support has a distal hole opening into a distal face of the distal portion of the primary support, and the implantation ancillary comprises a positioning punch provided with a tip-shaped distal end intended for anchorage in a vertebra, said positioning punch being shaped so as to slidably guide the primary support longitudinally by insertion of the positioning punch inside the distal hole.

30. The implantation ancillary according to claim 17, wherein the support means provided on the distal portion of the implant-holder comprise complementary pivot means shaped so as to cooperate with pivot means of a rear portion of the implant in order to enable a pivoting of said interspinous vertebral implant around a transverse axis.

31. The implantation ancillary according to claim 30, wherein the support means comprise two support elements having inner faces facing each other and respectively provided with recesses or protrusions shaped at least partially in a circular arc centered on the transverse axis and forming the complementary pivot means.

32. The implantation ancillary according to claim 31, wherein the two support elements are detachably attached to one another and, to this end, are provided with removable attachment means so that the two support elements can be configured between an attached configuration to allow supporting the interspinous vertebral implant, and a detached configuration to allow releasing the interspinous vertebral implant from the implant-holder.

33. The implantation ancillary according to claim 32, wherein the removable attachment means are formed by an upper slide and by an upper rail which are provided on the respective support elements.

34. The implantation ancillary according to claim 33, wherein the upper slide and the upper rail are both arcuate and with complementary shapes and extend between an anterior face and a posterior face of the distal portion of the implant-holder, to form pivot guide means adapted to cooperate together so as to pivotably guide a support element relative to the other support element around the transverse axis.

35. The implantation ancillary according to claim 31, wherein the distal portion and the proximal portion of the implant-holder are linked by two rods, said rods having distal ends fastened on the respective support elements and proximal ends, opposite to their distal ends, which are removably fastened on the proximal portion.

36. The implantation ancillary according to claim 35, wherein the distal ends of the rods have respective terminations which project from the respective support elements, in order to be able to bear against respective blocking plates of the implant.

37. The implantation ancillary according to claim 17, wherein the implantation ancillary comprises an impactor removably mounted on the proximal portion of the implant-holder.

38. The implantation ancillary according to claim 37, wherein the impactor comprises an impaction rod provided with a distal end fastened on the proximal portion of the implant-holder, and with a proximal end, opposite to the distal end, and on which a grip is fastened.

39. The implantation ancillary according to claim 38, wherein the impactor further comprises an impaction sleeve slidably mounted around the impaction rod, between the grip and the proximal portion of the implant-holder.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0123] Other features and advantages of the present disclosure will appear upon reading the detailed description hereinafter, of a non-limiting example of implementation, made with reference to the appended schematic figures wherein:

[0124] FIG. 1 is a perspective illustration on the posterior side of an example of an interspinous vertebral implant according to the disclosure;

[0125] FIG. 2 is a front illustration (front side) of the implant of FIG. 1;

[0126] FIG. 3 is a bottom illustration (internal face side) of the implant of FIG. 1;

[0127] FIG. 4 is a perspective illustration on the anterior side of the implant of FIG. 1;

[0128] FIG. 5 is a back illustration (rear side) of the implant of FIG. 1;

[0129] FIG. 6 is an illustration of the posterior side of the implant of FIG. 1;

[0130] FIG. 7 is an illustration of the anterior side of the implant of the FIG. 1;

[0131] FIG. 8 is a perspective illustration (view of the back and of the posterior side) of the implant of FIG. 1 in place between two spinous processes;

[0132] FIG. 9 is a perspective illustration (view of the front and of the posterior side) of the implant of FIG. 1 in place between two spinous processes;

[0133] FIG. 10 is an illustration of the posterior side of the implant of FIG. 1 in place between two spinous processes; and

[0134] FIG. 11 is an illustration of a first step of inserting a positioning punch of the implantation ancillary according to the disclosure;

[0135] FIG. 12 is an illustration of a second step of inserting a primary support of the implantation ancillary according to the disclosure;

[0136] FIG. 13 is a perspective illustration of the distal portion of the primary support of FIG. 12, according to two distinct viewpoints;

[0137] FIG. 14 is an illustration of a third step of coupling a holding grip on the primary support, and of a fourth step of inserting an implantation spindle of the implantation ancillary according to the disclosure;

[0138] FIG. 15 is a perspective illustration of the holding grip of FIG. 14 alone;

[0139] FIG. 16 is an enlarged and perspective illustration of the distal portion of the primary support on which the distal end portion of the implantation spindle is guided during the fourth step of FIG. 14;

[0140] FIG. 17 is a perspective illustration of the implantation spindle of FIG. 14 alone, according to several viewpoints and entirely (the left-side view) or partially (the three right-side views);

[0141] FIG. 18 is an illustration of a fifth step of pivoting (or tilting) the implantation spindle relative to the static primary support;

[0142] FIG. 19 is a perspective illustration of the implantation ancillary set according to the disclosure, comprising an ancillary-holder supporting the implant of FIG. 1, and further comprising an impactor mounted on the implant-holder;

[0143] FIG. 20 is a perspective illustration of the implant-holder of FIG. 19 alone;

[0144] FIG. 21 is a perspective illustration of the distal portion of the implant-holder of FIG. 19, with its two support elements in the attached configuration (to the left) and in the detached configuration (to the right);

[0145] FIG. 22 is an illustration of a sixth step of inserting the ancillary-holder and impactor set of FIG. 19, the ancillary-holder supporting the implant of FIG. 1;

[0146] FIG. 23 is an enlarged and perspective illustration of the distal portion of the primary support and of the distal end portion of the implantation spindle on which slides the implant carried by the implant-holder of FIG. 19;

[0147] FIG. 24 is an enlarged and perspective illustration of the distal portion of the primary support and of the distal end portion of the implantation spindle on which slides the implant carried by the implant-holder of FIG. 19;

[0148] FIG. 25 is an illustration of the beginning of a seventh step of pushing the implant of FIG. 1 which slides on the implantation spindle in the direction of the interspinous space between the two spinous processes;

[0149] FIG. 26 is an enlarged and perspective illustration of the implant which slides on the implantation spindle at the beginning of the seventh step of FIG. 25;

[0150] FIG. 27 is an illustration of the end of the seventh step of pushing the implant of FIG. 1 which has slid on the implantation spindle and which is henceforth positioned between the two spinous processes;

[0151] FIG. 28 is an enlarged and perspective illustration of the implant on the implantation spindle at the end of the seventh step of FIG. 27;

[0152] FIG. 29 is an illustration of an eighth step of removing the impactor off the implant-holder;

[0153] FIG. 30 is an illustration of a ninth step of unlocking the implant-holder by making its two support ends switch into the detached configuration;

[0154] FIG. 31 is an enlarged and perspective illustration of the implant and of the implant-holder during the ninth step of FIG. 30; and

[0155] FIG. 32 is an illustration of a tenth step of removing the implantation spindle, after having removed the implant-holder following the ninth step of FIG. 30.

DETAILED DESCRIPTION OF THE DRAWINGS

[0156] For simplicity, elements that are identical or ensuring the same function will bear the same references for the different embodiments.

[0157] The implant 1 according to the disclosure will now be described with reference to FIGS. 1 to 7. This implant 1 according to the disclosure is an interspinous vertebral implant including an implant body 10 made of at least one biocompatible material. More specifically, this implant 1 is formed integrally and solely by this implant body 10.

[0158] This implant body 10 extends along a longitudinal axis AL and it comprises successively along this longitudinal axis AL: [0159] a rear portion 2 having a rear end 20, [0160] a central portion 3 shaped so as to extend between two spinous processes AE (as shown in FIGS. 8 to 10) of two adjacent vertebrae VE, this central portion 3 extending the rear portion 2, and [0161] a front portion 4 extending the central portion 3, opposite to the rear portion 3, while tapering up to a streamline-shaped front end 40.

[0162] Thus, the central portion 3 links the rear portion 2 to the front portion 4, and this central portion 3 extends between the rear portion 2 to the front portion 4.

[0163] It should be noted that the central portion 3 may have some elasticity, in comparison with the front portion 2, enabling a bending of the central portion 3 throughout its insertion path, in particular throughout the curvilinear component of this insertion path. Once inserted, this flexibility of the implant body 1 allows preserving movability between the two adjacent vertebrae within a given range. This elasticity of the central portion 3, which contributes in having an implant body 10 with two “areas” with different rigidity/flexibility, may be obtained for example by geometric modifications (for example, lattice-type structure) and/or by the use of different materials.

[0164] The rear portion 2 has a half-disk like general shape with its rear end 20 which is rounded or rather a semi-cylindrical shape centered on a transverse axis AT that is perpendicular to the longitudinal axis AL.

[0165] This rear portion 2 has two opposite lateral faces 21, 22, respectively an upper face 21 and a lower face 22, with a half-disk like general shape, and means for pivoting around the transverse axis AT are provided on these two lateral faces 21, 22. For this purpose, the pivot means are provided in the form of recesses 23 formed on the respective lateral faces 21, 22 and shaped at least partially as a circular arc centered on the transverse axis AT. As shown in FIG. 3, a recess 23 is in the form of a circular arc shaped recess over an angular sector smaller than 180° C., such as for example and without limitation an angular sector comprised between 20 and 175 degrees.

[0166] As explained later on, these recesses 23 are intended to cooperate with complementary protrusions 941, 951 provided on an implant-holder 9 to enable a relative pivoting of the implant body 10 on this implant-holder 9 around the transverse axis AT.

[0167] At the junction between the rear portion 2 and the central portion 3, the rear portion 2 comprises a blocking plate 24 projecting on the lower side of the rear portion 2 (on the same side as the lower face 22) and another blocking plate 24 projecting on the upper side of the rear portion 2 (on the same side as the upper face 21).

[0168] The two blocking plates 24 are symmetrical with respect to a midplane PM including the longitudinal axis AL and orthogonal to the transverse axis AT, and the blocking plate 24 extends perpendicular to the lower face 22 whereas the other blocking plate 24 extends substantially perpendicular to the upper face 21.

[0169] These blocking plates 24 are coplanar extending in a plane substantially orthogonal to the longitudinal axis AL, or more generally in a plane inclined with respect to the longitudinal axis AL by an angle comprised between 60 and 120 degrees. In general, the implant body 10 is symmetrical with respect to this midplane PM.

[0170] The two blocking plates 24 project outwardly with respect to the respective lateral faces 21, 22, and also with respect to the central portion 3. The two blocking plates 24 are fastened and integral with the implant body 10. In a non-illustrated variant, the blocking plates 24 are articulated on the respective lateral faces 21, 22 or the blocking plates 24 are removably mounted on the lateral faces 21, 22.

[0171] Each of the two blocking plates 24 has a front face 240 directed towards the front end 40, and a rear face 241 opposite to the front face 240 and directed towards the rear end 20.

[0172] On each of the front faces 240 of the two blocking plates 24, several spikes 25 are provided forming anchoring reliefs configured to enable anchorage on a spinous process AE. These spikes 25 extend along directions parallel to the longitudinal axis AL. In turn, the rear faces 241 of the two blocking plates 24 are smooth.

[0173] The central portion 3 has two opposite lateral faces 31, 32 respectively an upper face 31 and a lower face 32, which are concave so as to define two recessed lateral faces 31, 32 adapted to fit between the two spinous processes AE. In other words, the central portion 3 is thinned at its center so as to conform with the shape of the spinous processes AE. The two blocking plates 24 project outwardly with respect to the respective lateral faces 31, 32.

[0174] The front portion 4 has a streamlined shape adapted to perforate ligament areas, and for this purpose, it comprises planar facets directly connected to each other by sharp and rectilinear edges converging towards the front end 40 tapering into a tip.

[0175] The implant body 10 also has an anterior face 11 intended to be directed towards the vertebrae VE, and a posterior face 12, opposite to the anterior face 11.

[0176] The anterior face 11 has a convex shape having a radius of curvature RC comprised between 20 and 300 millimeters, with a center of curvature located facing the posterior face 12 of the implant body 10. In turn, the posterior face 12 has a convex shape at the level of the central portion 3 and a planar facet shape at the level of the front portion 4.

[0177] The implant body 10 also has an anterior groove 5 formed in the anterior face 11 and completely crossing the implant body 10 from its rear end 20 up to its front end 40 so as to form, as described later on, a guide channel shaped so as to receive at least one portion of an implantation spindle 8 of an implantation ancillary described hereinafter.

[0178] As clearly shown in FIGS. 4 and 7, this 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.

[0179] This anterior groove 5 has a convex shape having the radius of curvature RC, and therefore extends from the rear end 20 up to the front end 40 along a circular arc shaped curvilinear direction. This anterior groove 5 extends in the midplane PM and it is symmetrical with respect to the midplane PM

[0180] Although some flexibility could be considered for the implant body 10, this implant body 10 does not form in any way an articulated body, in other words this implant body 10 is not articulated, to the extent that in a rest position (a position shown in FIGS. 1 to 7) as well as in an implanted position (a position shown in FIGS. 8 to 10 and 27 to 32), the anterior groove 5 has a curvilinear shape having the same curvature.

[0181] The anterior groove 5 is internally delimited by a bottom wall 50 offset in depth with respect to the anterior face by a given depth PR constant from the rear end 20 up to the front end 40, as shown in FIG. 5.

[0182] This bottom wall 50 has a convex shape with a center of curvature coincident with the center of curvature of the anterior face 11 and having a radius of curvature RP (not illustrated) smaller than the radius of curvature RC of this anterior face 11. The depth PR is measured along a radial direction passing through the center of curvature, so that RC=RP+PR.

[0183] This anterior groove 5 is internally delimited by two lateral walls 51, 52 parallel to the midplane PM and circular arc shaped. The spacing between the two lateral walls 51, 52 delimits the width LA of the anterior groove 5.

[0184] The anterior groove 5 is externally delimited by retaining lips 53 with a convex shape having the radius of curvature RC at the level of the anterior face 11. These retaining lips 53 project from the respective lateral walls 51, 52, moreover, they are disposed facing the bottom wall 50 and they extend facing each other so as to delimit a space that is narrow in comparison with the interior of the anterior groove 5. In other words, the spacing EC between the two retaining lips 53 is smaller than the width LA of the anterior groove 5. These retaining lips 53 are integral with the anterior face 11 into which the anterior groove 5 opens.

[0185] Each of the retaining lips 53 has a lip thickness or height HL, as shown in FIG. 5, measured along a radial direction passing through the center of curvature. Thus, the anterior groove 5 has a groove height HR, also measured along 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.

[0186] Moreover, the prior groove 5 is shaped so that: [0187] considering a first director and a second director parallel to the longitudinal axis AL, wherein the first director passes through the lowermost point of the bottom wall 50 (substantially at midway between the rear end 20 and the front end 40) and the second director passes through the uppermost point of the retaining lips 53 (at the level of the rear end 20 or of the front end 40), then the anterior groove 5 has a non-zero intermediate height HI, which corresponds to a distance measured between the first director and the second director along a direction orthogonal to the longitudinal axis AL and to the transverse axis AT, as shown in FIG. 5; and [0188] considering a third director parallel to the longitudinal axis AL, where the third director passes through the lowermost point of the retaining lips (substantially at midway 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 along a direction orthogonal to the longitudinal axis AL and to the transverse axis AT, as shown in FIG. 5.

[0189] Such a conformation is advantageous to allow making the implant 1 slide on a longitudinal rail 89 (described later on) along a longitudinal (in other words rectilinear) path and then a curved guide rail 83 (described later on) along a curved or arcuate path.

[0190] The anterior groove 5 has at its two respective ends a rear mouth 54 open onto the rear end 20, and a front mouth 55 open onto the front end 40.

[0191] The following description, made with reference to FIGS. 11 to 32, relates to the implantation ancillary intended for guidance and positioning of the implant 1 between two spinous processes AE of adjacent vertebrae VE, as well as the method for implanting the implant 1 by means of such an implantation ancillary.

[0192] This implantation ancillary is in the form of a kit comprising several distinct functional components cooperating together so as to enable an implantation of the implant 1 using a primarily dorsal approach. These different components of the implantation ancillary will be described progressively with their use in the implementation of the implantation method.

[0193] Beforehand, and with reference to FIG. 11, the surgeon determines a reference point located in a lateral portion PL of a vertebra VE, at a lateral distance DL with respect to the axis AC of the vertebral column CV (also called dorsal axis), such a lateral distance DL being determined beforehand before the surgery—for example between 5 and 70 millimeters. This reference point is substantially located in a midplane passing between the two spinous processes AE. Thus, the implantation method is called a primarily dorsal approach one, to the extent that it involves a dorsal approach slightly eccentric with respect to the dorsal axis by the lateral distance DL.

[0194] This prior step of determining the reference point may be carried out well ahead for example through the use of a preoperative scanner, the preoperative scanner also allowing measuring the width of the targeted interspinous space and selecting a size of the implant 1 according to this width.

[0195] Afterwards, the surgeon performs an incision at the lateral distance DL with respect to the axis AC of the vertebral column CV, above the reference point.

[0196] In a first step illustrated in FIG. 11, the surgeon moves away the different elements such as tissues, muscles, ligaments, etc. by means of a spacer (not illustrated) and he inserts, via a dorsal approach, a positioning punch 6 forming a component of the implantation ancillary, until anchoring it on the reference point.

[0197] This positioning punch 6 is a slender and rectilinear rod having a tip-shaped distal end 61. This positioning punch 6 has a rectangular cross-section, without this shape being restrictive as the positioning punch 6 could also have a circular, square, polygonal cross-section or others. The tip-shaped distal end 61 is anchored on the reference point in the vertebra PE lateral portion PL.

[0198] This positioning punch 6 also has a proximal end 62, opposite to the distal end 61, and the positioning punch 6 is long enough for this proximal end 62 projecting from the back of the patient.

[0199] In a second step illustrated in FIG. 12, the surgeon inserts a primary support 7 by making it slide on the positioning punch 6, as schematized by the arrow GU; this primary support 7 being another component of the implantation ancillary.

[0200] This primary support 7 is in the form of a tubular and slender body, having a distal portion 71 and a proximal portion 72 opposite to each other. The distal portion 71 has a distal face 710 directed towards the vertebra when in place, from which project several spikes 711 forming anchoring reliefs configured to enable anchorage on the vertebra VE lateral portion PL. The proximal portion 72 has a proximal face 720 directed outwardly, opposite to the distal face 710.

[0201] The primary support 7 has a distal hole 73 (shown in FIG. 13) opening into its distal face 710 and also has a proximal hole 730 (shown in FIG. 12) opening into its proximal face 720; these two holes 73, 730 may include two holes that are blind or open through into each other.

[0202] This primary support 7 is longer than the positioning punch 6 and the distal hole 73 is substantially longer than the positioning punch 6. Thus, the positioning punch 6 is shaped so as to slidably guide the primary support 7 longitudinally by insertion of the positioning punch 6 inside the distal hole 73.

[0203] The primary support 7 is introduced from outside at the level of the proximal end 62, by fitting at the level of the proximal face 720, and then the primary support 7 slides along the positioning punch 6 (as schematized by the arrow GU) until the spikes 711 come into contact with the vertebra VE lateral portion PL.

[0204] The distal portion 71 of the primary support 7 widens in the direction of the distal face 710 and it has a front face 712, directed in the direction of the spinous processes AE, having a curved and concave shape, from which projects a concave arcuate rail 74, having a dovetail cross-section.

[0205] In a third step illustrated in FIG. 12, the surgeon couples a holding grip 75 on the proximal portion 72 of the primary support 7, and more specifically fixes the holding grip 75 on the proximal face 720 of the primary support 7.

[0206] It should be noted that the holding grip 75 could, in a preferred variant, be already coupled to the primary support 7 during the above-described second step, so that the holding grip 75 is already fastened to the primary support 7 before the insertion of this primary support 7 for the surgeon to be able to properly hold the primary support 7/holding grip 75 set and make it slide on the positioning punch 6.

[0207] This holding grip 7 comprises a main body 76 prolonged on one side by a gripping head 77 and, on another side, by a fitting pin 78 adapted to fit into the proximal hole 730 of the primary support 7 for coupling. The gripping head 77 is provided with two lateral wings 770 enabling a manual gripping of the holding grip 7.

[0208] Advantageously, the gripping head 77 is mounted movable in rotation over 90 degrees on the main body 76, with a locking system allowing locking the gripping head 77 in a first position and in a second position after having turned by 90 degrees. Also, this locking system comprises an unlock button 771 located on the gripping head 77, at the middle and in line with the main body 70 between the two lateral wings 770, and which allows unlocking the rotation of the gripping head 77 to switch from the first position into the second position and vice versa.

[0209] Afterwards, the surgeon will exert, thanks to the holding grip 75, a push on the primary support 7 in order to anchor it into the vertebra VE lateral portion PL, by exerting a pushing force, and possibly an impaction force, preferably repeated, on the griping head 77 to ram the primary support 7.

[0210] In a fourth step illustrated in FIG. 14, the surgeon inserts an implantation spindle 8, another component of the implantation ancillary. As it will be explained later on, such an implantation spindle 8 could be pre-mounted on the primary support 7 so that the surgeon inserts the primary support 7/holding grip 75/implantation spindle 8 set together, in one single step.

[0211] This implantation spindle 8 has a distal end portion 81 which extends up to a free and tip-shaped distal end 810, and it also has a proximal end portion 82 which extends the distal end portion 81 up to a free proximal end 820.

[0212] As shown in FIGS. 16 and 17, the tip-shaped free distal end 810 has a tip angle smaller than 90 degrees, and preferably smaller than 45 degrees.

[0213] The distal end portion 81 has a curved shape and a curved guide rail is provided on this distal end portion 81. This guide rail 83 has a shape complementary with the anterior groove 5 of the implant 1, and has the same radius of curvature RC, to enable a sliding guidance of the implant 1 as described later on. The proximal end portion 82 has a rectilinear shape.

[0214] The curvature of the distal end portion 81 is such that this distal end portion 81 extends, with respect to the proximal end portion 82, over an angular sector in the range of 90 degrees, more or less 30 degrees. In particular, the distal end portion 81 is curved in a circular arc over the given radius of curvature RC over such an angular sector in the range of 90 degrees.

[0215] The implantation spindle 8 has a square or rectangular cross-section, over the entirety of its length starting from its distal end 810 up to its proximal end 820. The implantation spindle 8 has: [0216] an anterior face 87 directed towards the primary support 7 when in place; [0217] a posterior face 84 opposite to the anterior face 87 and directed towards the implant 1 during the insertion thereof; [0218] two lateral faces 85 opposite to each other, respectively an upper face and a lower face.

[0219] The guide rail 83 is made in the form of two notches 830 formed in the respective lateral faces 85 at the level of the distal end portion 81. The guide rail 83 extends up to the distal end 810, in other words the notches 830 extend up to the distal end 810.

[0220] This guide rail 83 is curved in a circular arc over the given radius of curvature RC over an angular sector in the range of 90 degrees, more or less 30 degrees.

[0221] Moreover, the guide rail 83 is prolonged, from the distal end portion 81, by a longitudinal rail 89 formed on the proximal end portion 82 and extending up to the proximal end 820. This longitudinal rail 89 is a rectilinear rail and it is formed by two notches 890 formed in the respective lateral faces 85 at the level of the proximal portion 82 and extending the notches 830.

[0222] Thus, the implantation spindle 8 successively has an arcuate guide rail 83 along the distal end portion 81, also arcuate, and a rectilinear longitudinal rail 89 along the proximal end portion 82, also rectilinear.

[0223] Moreover, the distal end portion 81 has an arcuate slide 86 formed on the anterior face 87. This arcuate slide 86 extends up to the distal end 810 over an angular sector in the range of 90 degrees, more or less 30 degrees.

[0224] In particular, this arcuate slide 86 extends only over the distal end portion 81 and stops at the beginning of the proximal end portion 82. In a non-illustrated variant, this arcuate slide 86 extends over the distal end portion 81 and extends over the proximal end portion 82 up to the proximal end 820, for example, if during manufacture thereof, the implantation spindle 8 is first extruded and then curved.

[0225] This arcuate slide 86 has a shape complementary with the arcuate rail 74 provided on the front face 712 of the distal portion 71 of the primary support 7. This arcuate rail 74 and this arcuate slide 86 respectively form a first pivot guide means and a second pivot guide means adapted to cooperate together so as to pivotably guide the implantation spindle 8 during an insertion of its distal end portion 81 between the two spinous processes AE.

[0226] Also, in the fourth step of inserting the implantation spindle 8, as shown in FIG. 14, the implantation spindle 8 is inserted with its proximal end portion 82 substantially perpendicular to the primary support 7, and with its distal end portion 81 which has its distal end 810 which points towards the front face 712 of the distal portion 71 of the primary support 7, until the arcuate slide 86 engages with the arcuate rail 74.

[0227] Although not illustrated, it is advantageous that the implantation spindle 8 is already pre-mounted on the primary support 7 in the non-tilted position (as shown in FIG. 14), so that the surgeon inserts the primary support 7/holding grip 75/implantation spindle 8 set together (in one single introduction step), by making the whole slide on the positioning punch 6 through an action on the holding grip 75.

[0228] However, should the surgeon have to move away more tissues in the axis of the lateral approach (axis AL of the implant 1) for example by means of a scraping tool such as a scraper, then in this case the implantation spindle 8 would not be mounted directly on the primary support 7 to facilitate spreading of the tissues.

[0229] In a fifth step illustrated in FIG. 18, the surgeon makes the implantation spindle 8 pivot (or tilt) relative to the anchored and static primary support 7, as schematized by the arrow PG, until the proximal end portion 82 is pressed against the primary support 7 and the distal end portion 81 extends partially between the two spinous processes AE.

[0230] As explained hereinabove, this pivoting of the implantation spindle 8 is carried out thanks to the cooperation between the arcuate slide 86 and the arcuate rail 74. The pivoting of the implantation spindle 8 is performed over an angle in the range of 90 degrees.

[0231] The dovetail complementary shapes of the arcuate slide 86 and the arcuate rail 74 allow maintaining the contact between the arcuate slide 86 and the arcuate rail 74 without any risk of detachment of the distal end portion 81 of the implantation spindle 8 off the primary support 7.

[0232] In a sixth step illustrated in FIG. 22, the surgeon inserts a set comprising an ancillary-holder 9 and an impactor 13; the ancillary-holder 9 and the impactor 13 being also components of the implantation ancillary.

[0233] Referring to FIGS. 19 and 20, the ancillary-holder 9 has a distal portion 91 and a proximal portion 92 opposite to each other, linked by two parallel rods 93.

[0234] The distal portion 91 is provided with support means shaped so as to support the implant 1, where these support means comprise two support elements 94, 95 having inner faces 940, 950 facing each other and respectively provided with protrusions 941, 951.

[0235] These protrusions 941, 951 are shaped at least partially in a circular arc centered on the transverse axis AT and they form pivot means complementary with the recesses 23 formed in the rear portion 2 of the implant 1 to enable a relative pivoting of the implant 1 on this implant-holder 9 around the transverse axis AT.

[0236] As shown in FIG. 21, each protrusion 941, 951 is in the form of a protrusion shaped in a circular arc over an angular sector smaller than 180 degrees, such as for example and without limitation an angular sector comprised between 20 and 175 degrees.

[0237] Moreover, the support elements 94, 95 also have respective arcuate faces 943, 953, which border the respective inner faces 940, 950, and which are shaped in a circular arc centered on the transverse axis AT, wherein these two arcuate faces 943, 953 are intended to conform to the rounded shape of the rear end 20 of the implant 1 so as to allow holding the implant 1 in place and also to allow transmitting a push on the implant 1 during the insertion thereof.

[0238] Thus, the protrusions 941, 951 carry the implant 1 which has its rear portion 2 wedged between the inner faces 940, 950 with the protrusions 941, 951 fitted in the recesses 23, and which also has its rounded rear end 20 bearing against the arcuate faces 943, 953.

[0239] The two rods 93 have distal ends fastened on the respective support elements 94, 95. Moreover, the two support elements 94, 95 are detachably attached to one another and, to this end, these support elements 94, 95 are provided with removable attachment means so that the two support elements 94, 95 can be configured between: [0240] an attached configuration (to the left in FIG. 21) to allow supporting the implant 1, and [0241] a detached configuration (to the right in FIG. 21) to allow releasing the implant 1 and thus removing the implant-holder 9 as described later on.

[0242] More specifically and as shown in FIG. 21, the removable attachment means are formed by an upper slide 942 and by an upper rail 952 which are provided on the respective support elements 94, 95, and vice versa.

[0243] This upper slide 942 and this upper rail 952 are both arcuate and with dovetail complementary shapes, and they extend between an anterior face and a posterior face of the distal portion 91; the anterior face being directed towards the implantation spindle 8 when in place and the posterior face, opposite to the anterior face, being directed towards the spinous processes AE when in place.

[0244] This upper slide 942 and this upper rail 952 form pivot guide means adapted to cooperate together so as to pivotably guide a support element 94 relative to the other support element 95, around the transverse axis AT.

[0245] 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 one another and can support the implant 1 on their protrusions 941, 951.

[0246] Moreover, it should be noted that the distal ends of the rods 93 have respective terminations 930 which project from the respective support elements 94, 95, and these terminations 930 are intended to bear against the rear faces 241 of the respective blocking plates 24 of the implant 1 (as shown in FIG. 23), in order to hold the implant 1 in place and also to allow transmitting a push on the implant 1 during the insertion thereof.

[0247] To switch from the attached configuration into the detached configuration, all it needs is to make one of the support elements 94, 95 pivot around the transverse axis AT, which does not hinder the implant 1, until the upper rail 952 completely comes out of the upper slide 942.

[0248] The anterior face of the distal portion 91 of the implant-holder 9 has a groove 96 to partially receive the implantation spindle 8, as shown in FIG. 23. This groove 96 being formed by two half-grooves facing each other and formed in the respective support elements 94, 95.

[0249] Each of the two rods 93 has a circular cross-section, without this shape being restrictive as each rod 93 could also have a rectangular, square, polygonal cross-section or others.

[0250] The two rods 93 have proximal ends, opposite to their distal ends, which are removably fastened on the proximal portion 92. This proximal portion 92 is in the form of an integral body which links the proximal ends of the two rods 93 to each other, and this proximal portion 92 could be detached from the proximal ends of the two rods 93 where necessary, as described later on.

[0251] The impactor 13 comprises an impaction rod 14 provided with a distal end fastened on the proximal portion 92, between the proximal ends of the two rods 93. This impaction rod 14 is also provided with a proximal end, opposite to the distal end, and on which is fastened a grip 15 formed by two lateral wings enabling a manual gripping of the impactor 13. The impactor 13 further comprises an impaction sleeve 16 slidably mounted around the impaction rod 14, between the grip 15 and the proximal portion 92 of the implant-holder 9.

[0252] Thus, thanks to the impactor 13, the surgeon can exert a push 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 a pushing force, preferably repeatedly, which includes holding with one hand the grip 15 and exerting with the other hand a sliding movement of the impaction grip 16 so that it impacts on the proximal portion 92; this impaction force being then transmitted through the rods 93 up to the support elements 94, 95, and finally through the terminations 930 and the arcuate faces 943, 953 up to the implant.

[0253] At the beginning of the sixth step, the implant 1 is engaged on the longitudinal rail 89 of the implantation spindle 8, along its posterior face 84, at the level of its proximal end 820, while engaging its anterior groove 5 by its front mouth 55 on the longitudinal rail 89, and with its front end 40 which points in the direction of the vertebra VE lateral portion PL.

[0254] More specifically, the retaining lips 53 of the anterior groove 5 are fitted inside the notches 890 formed in the respective lateral faces 85 of the implantation spindle 8. The retaining lips 53 allow maintaining contact between the anterior groove 5 and the longitudinal rail 89 without any risk of detachment of the implant 1 off the implantation spindle 8.

[0255] It should be noted that, because of the arcuate shape of the anterior groove 5 and its retaining lips 53, the longitudinal rail 86 is wider than the arcuate guide rail 83. In other words, and as shown in FIG. 17, the notches 890 of the longitudinal rail 89 have a width LR, and they are prolonged by the notches 830 which have a width LC smaller than LR.

[0256] More specifically, and as shown in FIG. 17, each notch 890 of the longitudinal rail 89 is delimited at the level of the posterior face 84 by a notch edge 891 having a thickness ER. Similarly, and as shown in FIG. 17, each notch 830 of the arcuate guide rail 83 is delimited at the level of the posterior face 84 by a notch edge 831 having a thickness EC, where EC is larger than ER, and where LR+ER=LC+EC. Thus, each notch edge 891 is prolonged by the corresponding notch edge 831, with a widening of one towards the other.

[0257] It should be noted that the thickness ER is substantially equivalent to the intermediate height HI of the anterior groove 5 (cf. FIG. 5), and the width LR is substantially equivalent to the overall height HG of the retaining lips 53 of the anterior groove 5 (cf. FIG. 5), so that the implant 1 could slide along a rectilinear path along the longitudinal rail 89, with the retaining lips 53 of its anterior groove 5 which slide in the notches 890; the notch edges 891 sliding, in turn, in the longitudinal interstice defined by this intermediate height HI.

[0258] Moreover, the thickness EC is substantially equivalent to the groove height HR of the anterior groove 5 (cf. FIG. 5), and the width LC is substantially equivalent to the lip height HL of the retaining lips 53 of the anterior groove 5 (cf. FIG. 5), so that the implant 1 could slide along an arcuate path (centered on the center of curvature of the anterior face 11 of the implant 1 which coincides 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.

[0259] During the sixth step, the surgeon therefore pushes on the implant-holder 9, by means of the impactor 13, to make the implant-holder 9 and the implant 1 descend along the longitudinal rail 89 and therefore along the proximal end portion 82 of the implantation spindle 8, as schematized by the arrow EN in FIG. 22, until the anterior groove 5 reaches the arcuate guide rail 83.

[0260] It should be noted that the surgeon has made the gripping head 77 of the holding grip 75 pivot by 90 degrees beforehand, after having pushed the unlock button 771, for the gripping head 77 to be able to pass between the two rods 93, as shown in FIG. 22.

[0261] In a seventh step illustrated in FIGS. 25 to 28, the surgeon continues pushing on the implant-holder 9, by means of the impactor 13, to make the implant 1 slide along the arcuate guide rail 83 (facing the posterior face 84) of the distal end portion 81, and therefore along a curvilinear path which makes the implant 1 pivot over an angle in the range of 90 degrees and move in the direction of the interspinous space between the two spinous processes AE, until the implant 1 reaches a final position between the two spinous processes AE, as shown in FIGS. 27 and 28.

[0262] In this seventh step, the retaining lips 53 of the anterior groove 5 are fitted inside the notches 830, after having passed through the notches 890. These retaining lips 53 allow maintaining contact between the anterior groove 5 and the guide rail 83 without any risk of detachment of the implant 1 off the implantation spindle 8.

[0263] During this curvilinear displacement of the implant 1, this implant 1 pivots relative to the implant-holder 9, thanks to the protrusions 941, 951 which cooperate with the recesses 23, and switches from an initial orientation substantially parallel to the primary support 7 into a final orientation substantially perpendicular to the primary support 7.

[0264] Thus, the implant-holder 9 pivots (or tilts) concomitantly with sliding of the implant 1, as schematized by the arrow BA in FIG. 25, with the proximal portion 92 which passes above the holding grip 75. During this insertion, the streamlined shape of the front portion 4 of the implant 1 allows spreading the two spinous processes AE, to fit its central portion 3 between the two spinous processes AE.

[0265] Once the implant 1 is in place, the surgeon can perform a control radio. Where needed, he can remove the implant 1 by pulling on the impaction head 15 to make the implant-holder 9 and therefore the implant 1 rise. If the implant is properly placed, the surgeon continues on to the eight step described hereinbelow.

[0266] In an eighth step illustrated in FIG. 29, the surgeon removes the impactor 13 off the implant-holder 9, and for this purpose, he detaches the proximal portion 92 of the rods 93 and he pulls on the grip 15 to remove this impactor 13.

[0267] In a ninth step illustrated in FIG. 30, the surgeon unlocks the implant-holder 9 by making its two support elements 94, 95 switch into the detached configuration.

[0268] For this purpose, the surgeon on the rods 93 to make a support element 94 pivot relative to the other support element 95, as schematized by the arrow MA in FIGS. 30 and 31, until the upper rail 952 completely comes out of the upper slide 942, as shown in FIG. 31.

[0269] Thus, the surgeon continues by completely removing the implant-holder 9 which is detached off the implant 1, by pulling on one rod 93 which carries with it the support element 94 attached thereto, and afterwards by pulling on the other rod 93 which carries with it the other support element 95 attached thereto.

[0270] In a tenth step illustrated in FIG. 32, the surgeon removes the implantation spindle 8, and for this purpose he makes the implantation spindle 8 pivot (or tilt) relative to the anchored and static primary support 7, as schematized by the arrow BR, to bring the proximal end portion 82 away from the primary support 7 and make the distal end portion 81 comes out of the anterior groove 5 (by its rear mouth 54) of the implant 1.

[0271] This pivoting of the implantation spindle 8 is performed over an angle in the range of 90 degrees, with a rotation opposite to that performed upon its implantation on the primary support 7.

[0272] Thus, the surgeon continues by completely removing the implantation spindle 8, then he pulls on the primary support 7, by means of the gripping head 77 of the holding grip 75, to remove the primary support 7, and finally the surgeon removes the positioning punch 6.

[0273] At this level, only the implant 1 is in place between the spinous processes AE, as illustrated in FIGS. 8 to 10, and the surgeon can finish the intervention, in particular by removing the spreader and by closing the incision.