Intersomatic prosthesis with lateral introduction

Abstract

An intersomatic prosthesis with lateral introduction with a prosthesis body symmetrical along a sagittal plane is provided. The intersomatic prosthesis includes a convex anterior lateral wall along an anterior radius of curvature and a convex posterior lateral wall along a posterior radius of curvature larger than the anterior radius of curvature, a right end wall and a left end wall, and a lower bearing wall and an upper bearing wall open onto an inner space. The lower bearing wall has a central lower portion provided with lower teeth having lower bearing tips defining a lower bearing surface which is planar, and the upper bearing wall has a central upper portion provided with upper teeth having upper bearing tips defining an upper bearing surface which is convex.

Claims

1. An intersomatic prosthesis for lateral introduction, said intersomatic prosthesis comprising: a prosthesis body symmetrical along a sagittal plane, extending along a longitudinal direction orthogonal to the sagittal plane, and comprising peripheral walls delimiting thereinside at least one inner space for receiving a bone substitute, said peripheral walls comprising: two opposite lateral walls, respectively an anterior lateral wall and a posterior lateral wall, wherein the anterior lateral wall is convex along an anterior radius of curvature and the posterior lateral wall is convex along a posterior radius of curvature, said anterior radius of curvature being smaller than the posterior radius of curvature, and wherein the anterior lateral wall has in the sagittal plane an anterior height and the posterior lateral wall has in the sagittal plane a posterior height, said anterior height being larger than or equal to said posterior height; two end walls, respectively a right end wall and a left end wall, extending symmetrically on either side of the sagittal plane; two opposite bearing walls, respectively a lower bearing wall and an upper bearing wall, wherein the bearing walls have openings on the inner space, respectively a lower opening and an upper opening; wherein: the lower bearing wall successively has, between the right end wall and the left end wall, a right lower portion projecting from the right end wall and continuously extended by a central lower portion provided with lower teeth having lower bearing tips defining a lower bearing surface which is planar, said central lower portion is extended by a left lower portion terminating in the left end wall; the upper bearing wall successively has, between the right end wall and the left end wall, a right upper portion projecting from the right end wall and continuously extended by a central upper portion provided with upper teeth having upper bearing tips defining an upper bearing surface which is convex along an upper radius of curvature, said central upper portion is extended by a left upper portion terminating in the left end wall; the right lower portion and the right upper portion extend in a convergent manner in the direction of the right end wall, so that the prosthesis body has a right end including the right lower portion and the right upper portion, and wherein said right end has a height, measured between the right lower portion and the right upper portion, which decreases along the longitudinal direction starting from the central lower portion in the direction of the right end wall; the left lower portion and the left upper portion extend in a convergent manner in the direction of the left end wall, so that the prosthesis body has a left end including the left lower portion and the left upper portion, and wherein said left end has a height, measured between the left lower portion and the left upper portion, which decreases along the longitudinal direction starting from the central lower portion in the direction of the left end wall.

2. The intersomatic prosthesis according to claim 1, wherein the anterior radius of curvature is between 30 and 70 millimeters.

3. The intersomatic prosthesis according to claim 1, wherein the posterior radius of curvature is between 90 and 220 millimeters.

4. The intersomatic prosthesis according to claim 1, wherein a ratio between the anterior radius of curvature and the posterior radius of curvature is between 0.3 and 0.35.

5. The intersomatic prosthesis according to claim 1, wherein the upper radius of curvature is between 90 and 160 millimeters.

6. The intersomatic prosthesis according to claim 5, wherein the upper radius of curvature is between 120 and 130 millimeters.

7. The intersomatic prosthesis according to claim 1, wherein the lower opening opens into the lower bearing wall at least over the entirety of the length of the central lower portion, such that the lower teeth comprise, on either side of the lower opening, a row of anterior lower teeth adjacent to the anterior lateral wall and a row of posterior lower teeth adjacent to the posterior lateral wall, and wherein the upper opening opens into the upper bearing wall at least over the entirety of the length of the central upper portion, such that the upper teeth comprise, on either side of the upper opening, a row of anterior upper teeth adjacent to the anterior lateral wall and a row of posterior upper teeth adjacent to the posterior lateral wall.

8. The intersomatic prosthesis according to claim 1, wherein the lower opening occupies between 50 and 75% of the surface area of the lower bearing wall, and the upper opening occupies between 50 and 75% of the surface area of the upper bearing wall.

9. The intersomatic prosthesis according to claim 1, wherein the right lower portion and the right upper portion consist of planar portions extending in respective convergent planes, inclined at a right angle of inclination smaller than 45 degrees, such that the right end has a height which decreases in a linear manner along the longitudinal direction starting from the central lower portion in the direction of the right end wall; and wherein the left lower portion and the left upper portion consist of planar portions extending in respective convergent planes, inclined at a left angle of inclination equal to the right angle of inclination, such that the left end has a height which decreases in a linear manner along the longitudinal direction starting from the central lower portion in the direction of the left end wall.

10. The intersomatic prosthesis according to claim 9, wherein the right angle of inclination and the left angle of inclination are between 5 and 30 degrees.

11. The intersomatic prosthesis according to claim 1, wherein the right upper portion is provided with at least two projecting spikes, and the left upper portion is provided with at least two projecting spikes.

12. The intersomatic prosthesis according to claim 11, wherein the projecting spikes project over a height between 0.7 and 1.2 millimeters.

13. The intersomatic prosthesis according to claim 1, wherein the right end has a right slot opening both into the right end wall and into the two lateral walls and configured to cooperate with a gripping ancillary, and the left end has a left slot symmetrical to the right slot with respect to the sagittal plane and opening both into the left end wall and into the two lateral walls and configured to cooperate with the gripping ancillary.

14. The intersomatic prosthesis according to claim 13, wherein the right slot extends, from the right end wall, into the posterior lateral wall over a posterior length and extends into the anterior lateral wall over an anterior length which is equal to or smaller than the posterior length, and the left slot extends, from the left end wall, into the posterior lateral wall over a posterior length and extends into the anterior lateral wall over the anterior length.

15. The intersomatic prosthesis according to claim 1, wherein the anterior height is larger than or equal to the posterior height such that in the sagittal plane the upper bearing wall has a lateral inclination with respect to the lower bearing wall at a lateral angle of inclination between 0 and 30 degrees.

16. The intersomatic prosthesis according to claim 1, wherein the prosthesis body has four rounded edges at junctures between the lateral walls and the bearing walls, said rounded edges extending longitudinally from the right end wall up to the left end wall following the respective curvatures of the lateral walls.

17. The intersomatic prosthesis according to claim 1, comprising at least three markers made of a radiopaque material, with a right marker placed on the right end wall and a left marker placed on the left end wall asymmetrically to the right marker with respect to the sagittal plane, and with a central marker placed on one of the lateral walls in the sagittal plane.

18. The intersomatic prosthesis according to claim 1, wherein an internal bridge extends inside the inner space between the two lateral walls, wherein said internal bridge is shifted downwards with respect to the upper bearing wall and is shifted upwards with respect to the lower bearing wall.

19. The intersomatic prosthesis according to claim 1, wherein a height, measured between the upper bearing wall and the lower bearing wall, decreases along the longitudinal direction, starting from the sagittal plane up to the right end wall, by 60 to 80%, and symmetrically with respect to the sagittal plane, a height, measured between the upper bearing wall and the lower bearing wall, decreases along the longitudinal direction, starting from the sagittal plane up to the left end wall, by 60 to 80%.

Description

DRAWINGS

(1) In order that the disclosure may be well understood, there will now be described various forms thereof, given by way of example, reference being made to the accompanying drawings, in which:

(2) FIG. 1 is a bottom schematic view (view on the lower bearing face) of an intersomatic prosthesis according to the present disclosure;

(3) FIG. 2 is a top schematic view (view on the upper bearing face) of the intersomatic prosthesis of FIG. 1;

(4) FIG. 3 is a schematic view of the posterior side (view on the posterior lateral face) of the intersomatic prosthesis of FIGS. 1 and 2;

(5) FIG. 4 is a schematic view of the left side (view on the left end face) of the intersomatic prosthesis of FIGS. 1 to 3;

(6) FIG. 5 is a schematic view of the right side (view on the right end face) of the intersomatic prosthesis of FIGS. 1 to 4;

(7) FIG. 6 is a sagittal sectional schematic view of the intersomatic prosthesis of FIGS. 1 to 5, along the sectional plane A-A visible in FIG. 1 corresponding to the sagittal plane;

(8) FIG. 7 is a horizontal sectional schematic view of the intersomatic prosthesis of FIGS. 1 to 6, along the sectional plane B-B visible in FIG. 3 corresponding to the horizontal plane;

(9) FIG. 8 is a perspective schematic view from the posterior and top side of the intersomatic prosthesis of FIGS. 1 to 7;

(10) FIG. 9 is a perspective schematic view from the anterior and top side of the intersomatic prosthesis of FIGS. 1 to 8;

(11) FIG. 10 is a perspective schematic view of the intersomatic prosthesis of FIGS. 1 to 9, with its prosthesis body shown transparent to visualize the three radiopaque material markers;

(12) FIG. 11 is a schematic view of the posterior side of the intersomatic prosthesis of FIGS. 1 to 10, with its prosthesis body shown transparent to visualize the three radiopaque material markers;

(13) FIG. 12 is a schematic view of the left side of the intersomatic prosthesis of FIGS. 1 to 11, with its prosthesis body shown transparent to visualize the three radiopaque material markers;

(14) FIG. 13 is a perspective schematic view of the intersomatic prosthesis of FIGS. 1 to 12 held on a gripping ancillary;

(15) FIG. 14 is a perspective schematic view of the intersomatic prosthesis of FIGS. 1 to 12 held on the gripping ancillary of FIG. 13, during the introduction of the intersomatic prosthesis between lower and upper vertebral endplates of an intervertebral space, formed respectively by the upper and lower faces of the sub- and super-jacent vertebrae;

(16) FIG. 15 is a perspective schematic view of the intersomatic prosthesis of FIGS. 1 to 12 held on the gripping ancillary of FIG. 13, with an enlarged view on the gripping head of the gripping ancillary and with the prosthesis body transparent;

(17) FIG. 16 is a top schematic view of the intersomatic prosthesis of FIGS. 1 to 12 held on the gripping ancillary of FIG. 13, with an enlarged view on the gripping head of the gripping ancillary and with the prosthesis body transparent;

(18) FIG. 17 is a schematic view of the anterior side of the intersomatic prosthesis of FIG. 1 to 12 in place between lower and upper vertebral endplates of an intervertebral space;

(19) FIG. 18 is an enlarged schematic view of FIG. 17;

(20) FIG. 19 is a schematic view of the right side of the intersomatic prosthesis of FIGS. 1 to 12 in place between lower and upper vertebral endplates of an intervertebral space; and

(21) FIG. 20 is a top schematic view of the intersomatic prosthesis of FIGS. 1 to 12 in place on a lower vertebral endplate of an intervertebral space.

(22) The drawings described herein are for illustration purposes only and are not intended to limit the scope of the present disclosure in any way.

DETAILED DESCRIPTION

(23) The following description is merely exemplary in nature and is not intended to limit the present disclosure, application, or uses. It should be understood that throughout the drawings, corresponding reference numerals indicate like or corresponding parts and features.

(24) Referring to FIGS. 1 to 12, an intersomatic prosthesis 1 with lateral introduction according to the present disclosure comprises a prosthesis body 10 symmetrical along a sagittal plane PS which, when in place, coincides with the sagittal plane of the vertebral column.

(25) This prosthesis body 10 is made integrally in one-piece and its shape substantially matches with an ovoid or elongated parallelepiped. This prosthesis body 10 is made of a bio-implantable or biocompatible material, such as for example a polymer, titanium, a stainless steel alloy, a metal-polymer mixed alloy, a mineral or synthetic material. As a non-limiting example, the body is made of polyether ether ketone (PEEK), polyether ketone ketone (PEKK).

(26) The prosthesis body 10 extends along a longitudinal direction X orthogonal to the sagittal plane PS and will coincide with its intervertebral introduction direction, in other words the guide direction of the lateral implantation thereof between the vertebral endplates PVI, PVS from the right or left side. This longitudinal direction X is contained in a horizontal plane PH, equivalent to the sectional plane B-B of FIG. 3, which is perpendicular to the sagittal plane PS. In the following description, a vertical plane PV, which contains the longitudinal direction X and which is perpendicular to both the sagittal plane PS and the horizontal plane PH, will also be considered.

(27) The prosthesis body 10 comprises peripheral walls 21, 22, 31, 32, 41, 42 delimiting thereinside at least one inner space 5 for receiving a bone substitute, including:

(28) two opposite lateral walls 21, 22, respectively an anterior lateral wall 21 and a posterior lateral wall 21, extending along the longitudinal direction and intended to extend substantially perpendicular to the lower and upper vertebral endplates PVI, PVS of an intervertebral space;

(29) two end walls 31, 32, respectively a right end wall 31 and a left end wall 32, extending symmetrically on either side of the sagittal plane PS;

(30) two opposite bearing walls 41, 42, respectively a lower bearing wall 41 and an upper bearing wall 42, where the lower bearing wall 41 is intended to bear against the lower vertebral endplate PVI and the upper bearing wall 42 is intended to bear against the upper vertebral endplate PVS.

(31) The anterior lateral wall 21 is convex along an anterior radius of curvature RA comprised between 30 and 70 millimeters, for example between 33 and 65 millimeters.

(32) The posterior lateral wall 22 is convex along a posterior radius of curvature RP which is larger than the anterior radius of curvature RA, and which is comprised between 90 and 220 millimeters, for example between 100 and 210 millimeters.

(33) Thus, the two lateral walls 21, 22 are convex and therefore cambered outwardly from the prosthesis body 10.

(34) Moreover, the anterior lateral wall 21 has in the sagittal plane PS an anterior height HA measured between the two bearing walls 41, 42, and the posterior lateral wall 22 has in the sagittal plane PS a posterior height HP, also measured between the two bearing walls 41, 42, and this anterior height HA is larger than the posterior height HP.

(35) In general, the prosthesis body 10 has a height corresponding to the anterior height HA which is comprised between 5 and 20 millimeters, for example between 8 and 16 millimeters. Regardless of the height of the prosthesis body 10, the height difference between the two lateral walls 21, 22, namely the difference DH=HA−HP, is comprised between 0 and 9.0 millimeters, for example between 0.5 and 5.25 millimeters, so that, in the sagittal plane PS, the upper bearing wall 42 has a lateral inclination with respect to the lower bearing wall 41 at a lateral angle of inclination AL which is comprised between 0 and 30 degrees, for example between 0 and 18 degrees.

(36) Complementarily, the prosthesis body 10 has a width LA corresponding to the distance between the two lateral walls 21, 22 measured in the sagittal plane and which is comprised between 16 and 24 millimeters, for example comprised between 18 millimeters and 22 millimeters. Furthermore, the prosthesis body 10 has a length LO (the distance between the end walls 31, 32 along the longitudinal direction X) comprised between 35 and 60 millimeters.

(37) The lower bearing wall 41 has a lower opening 51 which opens onto the inner space 50 and the upper bearing wall 42 has an upper opening 52 which opens onto the inner space 50.

(38) These openings 51, 52 have an oblong shape and extend along the longitudinal direction over at least half the overall length of the prosthesis body 10.

(39) The lower opening 51 occupies between 50 and 75% of the surface area of the lower bearing wall 41, and the upper opening 52 occupies between 50 and 75% of the surface area of the upper bearing wall 42.

(40) As shown in the figures, there is provided an internal bridge 53 extending inside the inner space 50 between the two lateral walls 21, 22; this internal bridge 53 being located in the sagittal plane PS. This internal bridge 53 extends substantially at mid-height between the two bearing walls 41, 42, so that this internal bridge 53 is shifted downwards with respect to the upper bearing wall 42 and is shifted upwards with respect to the lower bearing wall 41.

(41) The lower bearing wall 41 successively has, between the right end wall 31 and the left end wall 32:

(42) a right lower portion 411 projecting from the right end wall 31;

(43) a central lower portion 412 which continuously extends the right lower portion 411 and which is provided with lower teeth 611, 612; and

(44) a left lower portion 413 which continuously extends the central lower portion 412 and which terminates in the left end wall 32, where this left lower portion 413 is symmetrical to the right lower portion 411 with respect to the sagittal plane PS.

(45) On the central lower portion 412, the lower teeth 611, 612 have lower bearing tips (also called free ends or spikes of the lower teeth 611, 612) which define a lower bearing surface SAI which is planar. In other words, the lower bearing tips of these lower teeth 611, 612 extend in the same plane thereby forming a planar lower bearing surface SAI intended to bear against the lower vertebral endplate PVI. It should be noted that this lower bearing surface SAI is inclined in the sagittal plane PS with respect to the horizontal plane PH because of the height difference DH described hereinabove.

(46) All of the lower teeth 611, 612 have the same height, so that all of these lower teeth 611, 612 project from the same plane, parallel to the lower bearing surface SAI. These lower teeth 611, 612 have a height advantageously comprised between 0.7 and 1.2 millimeters, for example between 0.8 and 1.0 millimeters.

(47) These lower teeth 611, 612 are symmetrical teeth bordered by two sidewalls extending symmetrically on either side of their respective lower bearing tips, and with apex angles comprised between 70 and 120 degrees, for example 90 degrees. The lower teeth 611, 612 form rectilinear teeth oriented along directions parallel to the sagittal plane PS, so that all of their lower bearing tips extend parallel to the sagittal plane PS.

(48) As shown in FIG. 2, the lower opening 51 opens into the lower bearing wall 41 over at least the entirety of the central lower portion 412, so that the lower teeth 611, 612 comprise, on either side of the lower opening 51, a row of anterior lower teeth 611 adjacent to the anterior lateral wall 21 and a row of posterior lower teeth 612 adjacent to the posterior lateral wall 22.

(49) The right lower portion 411 is a planar and smooth portion, extending in the continuation of the lower bearing surface SAI defined by the lower bearing tips of the lower teeth 611, 612, and that in an inclined manner in the vertical plane PV with respect to the horizontal plane PH (and also with respect to the lower bearing surface SAI) in the direction of a reduction of the height along the longitudinal direction X starting from the central lower portion 412 in the direction of the right end wall 31. It should be noted that this right lower portion 411 is also inclined in the sagittal plane PS with respect to the horizontal plane PH because of the height difference DH described hereinabove.

(50) The left lower portion 413 is a planar and smooth portion, extending in the continuation of the lower bearing surface SAI, and that in an inclined manner in the vertical plane PV with respect to the horizontal plane PH (and also with respect to the lower bearing surface SAI) in the direction of a reduction of the height along the longitudinal direction X starting from the central lower portion 412 in the direction of the left end wall 32. It should be noted that this left lower portion 413 is also inclined in the sagittal plane PS with respect to the horizontal plane PH because of the height difference DH described hereinabove.

(51) The upper bearing wall 42 successively has, between the right end wall 31 and the left end wall 32:

(52) a right upper portion 421 projecting from the right end wall 31;

(53) a central upper portion 422 which continuously extends the right upper portion 421 and which is provided with upper teeth 621, 622; and

(54) a left upper portion 423 which continuously extends the central upper portion 422 and which terminates in the left end wall 32, where this left upper portion 423 is symmetrical to the right upper portion 421 with respect to the sagittal plane PS.

(55) On the central upper portion 422, the upper teeth 621, 622 have upper bearing tips (also called free ends or apices of the upper teeth 621, 622) which define an upper bearing surface SAS which is convex along an upper radius of curvature RS which is comprised between 90 and 160 millimeters, for example between 100 and 150 millimeters and between 120 and 130 millimeters. In other words, the upper bearing tips of these upper teeth 621, 622 extend in the same convex fictional surface thereby forming a convex upper bearing surface SAS intended to bear against the upper vertebral endplate PVS. It should be noted that this upper bearing surface SAS is inclined in the sagittal plane PS with respect to the horizontal plane PH because of the height difference DH described hereinabove.

(56) All of the upper teeth 621, 622 have the same height, so that all of these upper teeth 621, 622 project from the same surface which is convex along the same upper radius of curvature RS. These upper teeth 621, 622 has a height advantageously comprised between 0.7 and 1.2 millimeters, for example between 0.8 and 1.0 millimeters, and which is equivalent to that of the lower teeth 611, 612.

(57) These upper teeth 621, 622 are symmetrical teeth bordered by two sidewalls extending symmetrically on either side of their respective upper bearing tips, and with apex angles comprised between 70 and 120 degrees, for example 90 degrees. The upper teeth 621, 622 form rectilinear teeth oriented along directions parallel to the sagittal plane PS, so that all of their upper bearing tips extend parallel to the sagittal plane PS.

(58) As shown in FIG. 1, the upper opening 52 opens into the upper bearing wall 42 over at least the entirety of the central upper portion 412, so that the upper teeth 621, 622 comprise, on either side of the upper opening 52, a row of anterior upper teeth 621 adjacent to the anterior lateral wall 21 and a row of posterior upper teeth 622 adjacent to the posterior lateral wall 22.

(59) The right upper portion 421 is a planar and smooth portion, extending in the continuation of the upper bearing surface SAS defined by the upper bearing tips of the upper teeth 621, 622, and that tangentially to the upper bearing surface SAS. Moreover, the right upper portion 421 is inclined in the vertical plane PV with respect to the horizontal plane PH in the direction of a reduction of the height along the longitudinal direction X starting from the central upper portion 422 in the direction of the right end wall 31. It should be noted that this right upper portion 421 is also inclined in the sagittal plane PS with respect to the horizontal plane PH because of the height difference DH described hereinabove. It should also be noted that this right upper portion 421 is symmetrical to the right lower portion 411 with respect to the horizontal plane PH.

(60) Hence, the right lower portion 411 and the right upper portion 421 extend in a convergent manner in the direction of the right end wall 31, and more specifically the right lower portion 411 and the right upper portion 421 are planar portions extending in respective convergent planes, inclined in the vertical plane PV at a right angle of inclination AD smaller than 45 degrees, for example comprised between 5 and 30 degrees.

(61) Thus, the prosthesis body 10 has a right end including the right lower portion 411 and the right upper portion 421, and this right end has a height, measured between the right lower portion 411 and the right upper portion 421, which decreases along the longitudinal direction starting from the central lower portion 412 (or of the central upper portion 422) in the direction of the right end wall 31. Advantageously, the height, measured between the upper bearing wall 42 and the lower bearing wall 41, decreases along the longitudinal direction X, starting from the sagittal plane PS up to the right end wall 31, by 60 to 80%, and for example by about 75%.

(62) The left upper portion 423 is a planar and smooth portion, extending in the continuation of the upper bearing surface SAS, and that tangentially to the upper bearing surface SAS. Moreover, the left upper portion 423 is inclined in the vertical plane PV with respect to the horizontal plane PH in the direction of a reduction of the height along the longitudinal direction X starting from the central upper portion 422 in the direction of the left end wall 32. It should be noted that this left upper portion 423 is also inclined in the sagittal plane PS with respect to the horizontal plane PH because of the height difference DH described hereinabove. It should also be noted that this left upper portion 423 is symmetrical to the left lower portion 413 with respect to the horizontal plane PH.

(63) Hence, the left lower portion 413 and the left upper portion 423 extend in a convergent manner in the direction of the left end wall 32, and more specifically the left lower portion 413 and the left upper portion 423 are planar portions extending in respective convergent planes, inclined in the vertical plane PV at a left angle of inclination AG smaller than 45 degrees, for example comprised between 5 and 30 degrees; this left angle of inclination AG being equivalent to the right angle of inclination AD because of the symmetry with respect to the sagittal plane PS. Advantageously, the height, measured between the upper bearing wall 42 and the lower bearing wall 41, decreases along the longitudinal direction X, starting from the sagittal plane PS up to the left end wall 32, by 60 to 80%, and for example by about 75%; this decrease being equivalent to that achieved on the right side because of the symmetry with respect to the sagittal plane PS.

(64) Thus, the prosthesis body 10 has a left end including the left lower portion 413 and the left upper portion 423, and this left end has a height, measured between the left lower portion 413 and the left upper portion 423, which decreases along the longitudinal direction starting from the central lower portion 412 (or of the central upper portion 422) in the direction of the left end wall 32.

(65) Hence, the prosthesis body 10 has right and left ends which are refined symmetrically on either side of the sagittal plane PS, so that the end walls 31, 32 have the same small heights in order to enable an easy introduction between the vertebral endplates PVI, PVS.

(66) Moreover, it should be noted that the right upper portion 421 is provided with two projecting spikes 63, disposed on either side of the vertical plane PV. In an equivalent manner, the left upper portion 423 is also provided with two projecting spikes 64, disposed on either side of the vertical plane PV, these two spikes 64 being symmetrical to the spikes 63 with respect to the sagittal plane PS.

(67) These spikes 63, 64 have projecting angles intended for an anterior-posterior and right-left lateral fastening in the upper vertebral endplate PVS, with the result of locking the intersomatic prosthesis 1 and inhibiting or preventing any migration out of the intersomatic space. These spikes 63, 64 project from the right and left upper portions 421, 423 over a height comprised between 0.7 and 1.2 millimeters, for example between 0.8 and 1.0 millimeters.

(68) Furthermore, the prosthesis body 10 has four rounded edges 100 at the junctures between the lateral walls 21, 22 and the bearing walls 41, 42, therefore with a first rounded edge 100 between the anterior lateral wall 21 and the lower bearing wall 41, a second rounded edge 100 between the anterior lateral wall 21 and the upper bearing wall 42, a third rounded edge 100 between the posterior lateral wall 22 and the lower bearing wall 41, and finally a fourth rounded edge 100 between the posterior lateral wall 22 and the upper bearing wall 42. These rounded edges 100, which are in particular in the form of connecting fillets, extending longitudinally from the right end wall 31 up to the left end wall 32 following the respective curvatures of the lateral walls 21, 22, and therefore over the entirety of the length of the prosthesis body 10.

(69) Moreover, the right end of the prosthesis body 10 has a right slot 71 opening both into the right end wall 31 and into the two lateral walls 21, 22. In an equivalent manner, the left end of the prosthesis body 10 has a left slot 72 opening both into the left end wall 32 and into the two lateral walls 21, 22; this left slot 72 being symmetrical to the right slot 71 with respect to the sagittal plane PS.

(70) These two slots 71, 72 form two recessed furrows having a “U”-like general shape and which are intended to cooperate with a gripping ancillary 9, depending on the approach way. If the approach way is a right approach way, then the gripping ancillary 9 will cooperate with the right slot 71, and if the approach way is a left approach way, then the gripping ancillary 9 will cooperate with the left slot 72.

(71) In the form shown in FIGS. 7, 15 and 16, it should be noted that the right slot 71 extends from the right end wall 31 over a larger length of the side of the posterior lateral wall 22 than the side of the anterior lateral wall 21. In other words, the right slot 71 extends, from the right end wall 31:

(72) in the posterior lateral wall 22 over a determined posterior length LFP, and

(73) in the anterior lateral wall 21 over a determined anterior length LFA which is smaller than the posterior length LFP.

(74) In an equivalent manner, the left slot 72 extends from the left end wall 32 over a larger length of the side of the posterior lateral wall 22 than the side of the anterior lateral wall 21. In other words, the left slot 72 extends, from the left end wall 32:

(75) in the posterior lateral wall 22 over the aforementioned posterior length LFP, and

(76) in the anterior lateral wall 21 over the aforementioned anterior length LFA which is smaller than the posterior length LFP.

(77) In a variant that is not illustrated, the right slot 71 extends from the right end wall 31 over the same length on the side of the posterior lateral wall 22 and on the side of the anterior lateral wall 21. In other words, the right slot 71 extends, from the right end wall 31:

(78) in the posterior lateral wall 22 over a determined posterior length LFP, and

(79) in the anterior lateral wall 21 over a determined anterior length LFA which is equal to the posterior length LFP.

(80) Also, still in this non-illustrated variant, the left slot 72 extends from the left end wall 32 over the same length on the side of the posterior lateral wall 22 and on the side of the anterior lateral wall 21. In other words, the left slot 72 extends, from the left end wall 32:

(81) in the posterior lateral wall 22 over the aforementioned posterior length LFP, and

(82) in the anterior lateral wall 21 over the aforementioned anterior length LFA which is equal to the posterior length LFP.

(83) There is also provided a right hole 710 formed in the right end wall 31 and extending along the longitudinal direction X, this right hole 710 opening into the right slot 71 and into the inner space 50. In an equivalent manner, there is also provided a left hole 720 formed in the left end wall 32 and extending along the longitudinal direction X, this left hole 720 opening into the left slot 72 and into the inner space 50; this left hole 720 being symmetrical to the right hole 710 with respect to the sagittal plane PS. These two holes 710, 720 are also intended to cooperate with the gripping ancillary 9.

(84) For this purpose, and as illustrated in FIGS. 13 to 16, the gripping ancillary 9 comprises:

(85) a handle 90 provided with an impingement surface 900 to allow impinging the gripping ancillary 9 and the intersomatic prosthesis 1;

(86) a rod 91 extending the handle 90; and

(87) a gripping head 92 having a fork-like general shape adapted to cooperate with the prosthesis body 10.

(88) This gripping head 92 is provided with:

(89) an anterior arm 93 adapted to fit into the portion of the right or left slot 71, 72 which is formed in the anterior lateral wall 21;

(90) a posterior arm 94 adapted to fit into the portion of the right or left slot 71, 72 which is formed in the posterior lateral wall 22;

(91) a central stud 95, embedded between the two arms 93, 94, and which is adapted to fit inside the right or left hole 710, 720.

(92) The anterior arm 93 is shorter than the posterior arm 94 because the anterior length LFA is smaller than the posterior length LFP, as explained hereinabove.

(93) Alternatively, the anterior arm 93 is as long as the posterior arm 94, in particular if the anterior length LFA is equal to the posterior length LFP.

(94) As shown in FIGS. 14 and 17 to 20, the intersomatic prosthesis 1 is intended to be implanted along, laterally (a right or left approach way) by means of the previously described gripping ancillary 9, between the upper vertebral endplate PVS and the lower vertebral endplate PVI of an intervertebral space, these vertebral endplates PVS, PVI being formed respectively by the lower face of a super-jacent vertebra VU and by the upper face of a sub-jacent vertebra VO delimiting the intervertebral space (or intersomatic space).

(95) Once in place, the lower bearing wall 41 bears against the lower vertebral endplate PVI and the upper bearing wall 42 bears against the upper vertebral endplate PVS, and the anterior lateral wall 21 is turned on the anterior side CA of the vertebral column whereas the posterior lateral wall 22 is turned on the posterior side CP of the vertebral column, with the sagittal plane PS of the prosthesis body 10 coincident or coplanar with the sagittal plane of the vertebral column.

(96) In order to guide the positioning of the intersomatic prosthesis 1, it is advantageous that this intersomatic prosthesis 1 incorporates, on or within the prosthesis body 10, markers 91, 92, 93 made of a radiopaque material, for example three markers, namely:

(97) a right marker 91 placed on the right end wall 31;

(98) a left marker 92 placed on the left end wall 32 asymmetrically to the right marker 91 with respect to the sagittal plane PS; and

(99) a central marker 93 placed on any of the lateral walls 21, 22 in the sagittal plane PS.

(100) All of the markers 91, 92, 93 are in the form of cylindrical studs 91, 92, 93, having a dimeter comprised between 1 and 2 millimeters and a length comprised between 2 and 5 millimeters.

(101) The right and left markers 91, 92 extend vertically and are disposed in the same plane PM parallel to the vertical plane PV, yet with the right marker 91 which is shifted upwards (and therefore closer to the upper bearing wall 42) whereas the left marker 91 is shifted downwards (and therefore closer to the upper bearing wall 42). Thus, and as shown in FIG. 12, viewed from the (right or left) side, the right and left markers 91, 92 are aligned and partially coincident, thereby allowing monitoring an orientation with respect to the horizontal plane PH or to the vertical plane PV. In turn, the central marker 93 extends horizontally, and perpendicular to the longitudinal direction X. In particular, it is disposed in the anterior lateral wall 21, at mid-height thereof.

(102) All markers 91, 92, 93 are received into the orifices 910, 920, 930 formed in the prosthesis body 10 for the reception thereof, as shown in FIG. 7.

(103) Hence, the previously described prosthesis 10 is remarkable in that the sagittal symmetry enables it to be advantageously implanted by a left or right approach way, while preserving properties of anatomical adaptation to the vertebral endplates PVI, PVS. The thinned left and right ends, associated to the rounded edges 100, enable a safe and non-traumatic impingement of the intersomatic prosthesis 1 during the penetration, these rounded edges 100 following the curvatures of the lateral walls 21, 22, thereby preserving the neurological and vascular structures located on the approach way on either side of the vertebrae VO, VU.

(104) The intersomatic prosthesis 1 may be set in place from the left or the right; its positioning being achieved by means of the appropriate gripping ancillary 9, endoscopically or in “open surgery”. Where desired, the intersomatic prosthesis 1 could be removed.

(105) Hence, this intersomatic prosthesis 1 has a geometrically sophisticated design, but its implementation is simple and conforms perfectly to the shape of the vertebral endplates PVI, PVS without any risk of degradation of these vertebral endplates PVI, PVS, and which provides safety in particular thanks to its spikes 63, 64 forming anti-recoil devices, so as to provide a perfect primary stability (thanks to the teeth 611, 612, 621, 622) before osteosynthesis of the treated segment on the one hand and to optimally rectify a lordosis and/or a kyphosis on the other hand and thus improve the surgical treatment.

(106) An advantage provided by this intersomatic prosthesis 1 lies in significantly reducing the risks of disc degeneration at the adjacent levels, known under the name of lumbosacral transitional vertebrae disc disease. Indeed, it is perfectly established that a balanced rebuild of the spinal column reduces or minimizes the forces and the actions of the muscles of the back but also of the legs because the patient does not make his body work to «straighten the spinal column» in the optimum position. The present intersomatic prosthesis 1 enables the surgeon to carry out a rebuild and to obtain a lordosis correction promoting an optimum sagittal balance, thereby reducing the risks of re-operation subsequent to a lumbosacral transitional vertebrae degeneration.

(107) Unless otherwise expressly indicated herein, all numerical values indicating mechanical/thermal properties, compositional percentages, dimensions and/or tolerances, or other characteristics are to be understood as modified by the word “about” or “approximately” in describing the scope of the present disclosure. This modification is desired for various reasons including industrial practice, material, manufacturing, and assembly tolerances, and testing capability.

(108) As used herein, the phrase at least one of A, B, and C should be construed to mean a logical (A OR B OR C), using a non-exclusive logical OR, and should not be construed to mean “at least one of A, at least one of B, and at least one of C.”

(109) The description of the disclosure is merely exemplary in nature and, thus, variations that do not depart from the substance of the disclosure are intended to be within the scope of the disclosure. Such variations are not to be regarded as a departure from the spirit and scope of the disclosure.