Classifications

• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B17/00—Surgical instruments, devices or methods, e.g. tourniquets
  • A61B17/56—Surgical instruments or methods for treatment of bones or joints; Devices specially adapted therefor
  • A61B17/58—Surgical instruments or methods for treatment of bones or joints; Devices specially adapted therefor for osteosynthesis, e.g. bone plates, screws, setting implements or the like
  • A61B17/68—Internal fixation devices, including fasteners and spinal fixators, even if a part thereof projects from the skin
  • A61B17/70—Spinal positioners or stabilisers ; Bone stabilisers comprising fluid filler in an implant
  • A61B17/7001—Screws or hooks combined with longitudinal elements which do not contact vertebrae
  • A61B17/7002—Longitudinal elements, e.g. rods
  • A61B17/7004—Longitudinal elements, e.g. rods with a cross-section which varies along its length
  • A61B17/7007—Parts of the longitudinal elements, e.g. their ends, being specially adapted to fit around the screw or hook heads
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B17/00—Surgical instruments, devices or methods, e.g. tourniquets
  • A61B17/56—Surgical instruments or methods for treatment of bones or joints; Devices specially adapted therefor
  • A61B17/58—Surgical instruments or methods for treatment of bones or joints; Devices specially adapted therefor for osteosynthesis, e.g. bone plates, screws, setting implements or the like
  • A61B17/68—Internal fixation devices, including fasteners and spinal fixators, even if a part thereof projects from the skin
  • A61B17/70—Spinal positioners or stabilisers ; Bone stabilisers comprising fluid filler in an implant
  • A61B17/7001—Screws or hooks combined with longitudinal elements which do not contact vertebrae
  • A61B17/7002—Longitudinal elements, e.g. rods
  • A61B17/7011—Longitudinal element being non-straight, e.g. curved, angled or branched
  • A61B17/7013—Longitudinal element being non-straight, e.g. curved, angled or branched the shape of the element being adjustable before use
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B17/00—Surgical instruments, devices or methods, e.g. tourniquets
  • A61B17/56—Surgical instruments or methods for treatment of bones or joints; Devices specially adapted therefor
  • A61B17/58—Surgical instruments or methods for treatment of bones or joints; Devices specially adapted therefor for osteosynthesis, e.g. bone plates, screws, setting implements or the like
  • A61B17/68—Internal fixation devices, including fasteners and spinal fixators, even if a part thereof projects from the skin
  • A61B17/70—Spinal positioners or stabilisers ; Bone stabilisers comprising fluid filler in an implant
  • A61B17/7001—Screws or hooks combined with longitudinal elements which do not contact vertebrae
  • A61B17/7002—Longitudinal elements, e.g. rods
  • A61B17/7014—Longitudinal elements, e.g. rods with means for adjusting the distance between two screws or hooks
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B17/00—Surgical instruments, devices or methods, e.g. tourniquets
  • A61B17/56—Surgical instruments or methods for treatment of bones or joints; Devices specially adapted therefor
  • A61B17/58—Surgical instruments or methods for treatment of bones or joints; Devices specially adapted therefor for osteosynthesis, e.g. bone plates, screws, setting implements or the like
  • A61B17/68—Internal fixation devices, including fasteners and spinal fixators, even if a part thereof projects from the skin
  • A61B17/70—Spinal positioners or stabilisers ; Bone stabilisers comprising fluid filler in an implant
  • A61B17/7001—Screws or hooks combined with longitudinal elements which do not contact vertebrae
  • A61B17/7002—Longitudinal elements, e.g. rods
  • A61B17/7019—Longitudinal elements having flexible parts, or parts connected together, such that after implantation the elements can move relative to each other
  • A61B17/702—Longitudinal elements having flexible parts, or parts connected together, such that after implantation the elements can move relative to each other having a core or insert, and a sleeve, whereby a screw or hook can move along the core or in the sleeve
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B17/00—Surgical instruments, devices or methods, e.g. tourniquets
  • A61B17/56—Surgical instruments or methods for treatment of bones or joints; Devices specially adapted therefor
  • A61B17/58—Surgical instruments or methods for treatment of bones or joints; Devices specially adapted therefor for osteosynthesis, e.g. bone plates, screws, setting implements or the like
  • A61B17/68—Internal fixation devices, including fasteners and spinal fixators, even if a part thereof projects from the skin
  • A61B17/70—Spinal positioners or stabilisers ; Bone stabilisers comprising fluid filler in an implant
  • A61B17/7001—Screws or hooks combined with longitudinal elements which do not contact vertebrae
  • A61B17/7002—Longitudinal elements, e.g. rods
  • A61B17/7019—Longitudinal elements having flexible parts, or parts connected together, such that after implantation the elements can move relative to each other
  • A61B17/7031—Longitudinal elements having flexible parts, or parts connected together, such that after implantation the elements can move relative to each other made wholly or partly of flexible material
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B17/00—Surgical instruments, devices or methods, e.g. tourniquets
  • A61B17/56—Surgical instruments or methods for treatment of bones or joints; Devices specially adapted therefor
  • A61B17/58—Surgical instruments or methods for treatment of bones or joints; Devices specially adapted therefor for osteosynthesis, e.g. bone plates, screws, setting implements or the like
  • A61B17/68—Internal fixation devices, including fasteners and spinal fixators, even if a part thereof projects from the skin
  • A61B17/70—Spinal positioners or stabilisers ; Bone stabilisers comprising fluid filler in an implant
  • A61B17/7001—Screws or hooks combined with longitudinal elements which do not contact vertebrae
  • A61B17/7041—Screws or hooks combined with longitudinal elements which do not contact vertebrae with single longitudinal rod offset laterally from single row of screws or hooks
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B17/00—Surgical instruments, devices or methods, e.g. tourniquets
  • A61B17/56—Surgical instruments or methods for treatment of bones or joints; Devices specially adapted therefor
  • A61B17/58—Surgical instruments or methods for treatment of bones or joints; Devices specially adapted therefor for osteosynthesis, e.g. bone plates, screws, setting implements or the like
  • A61B17/68—Internal fixation devices, including fasteners and spinal fixators, even if a part thereof projects from the skin
  • A61B17/70—Spinal positioners or stabilisers ; Bone stabilisers comprising fluid filler in an implant
  • A61B17/7059—Cortical plates
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B17/00—Surgical instruments, devices or methods, e.g. tourniquets
  • A61B17/56—Surgical instruments or methods for treatment of bones or joints; Devices specially adapted therefor
  • A61B17/58—Surgical instruments or methods for treatment of bones or joints; Devices specially adapted therefor for osteosynthesis, e.g. bone plates, screws, setting implements or the like
  • A61B17/68—Internal fixation devices, including fasteners and spinal fixators, even if a part thereof projects from the skin
  • A61B17/80—Cortical plates, i.e. bone plates; Instruments for holding or positioning cortical plates, or for compressing bones attached to cortical plates
  • A61B17/8023—Variable length plates adjustable in both directions
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B17/00—Surgical instruments, devices or methods, e.g. tourniquets
  • A61B17/56—Surgical instruments or methods for treatment of bones or joints; Devices specially adapted therefor
  • A61B17/58—Surgical instruments or methods for treatment of bones or joints; Devices specially adapted therefor for osteosynthesis, e.g. bone plates, screws, setting implements or the like
  • A61B17/68—Internal fixation devices, including fasteners and spinal fixators, even if a part thereof projects from the skin
  • A61B17/84—Fasteners therefor or fasteners being internal fixation devices
  • A61B17/86—Pins or screws or threaded wires; nuts therefor
  • A61B17/8605—Heads, i.e. proximal ends projecting from bone
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B17/00—Surgical instruments, devices or methods, e.g. tourniquets
  • A61B17/56—Surgical instruments or methods for treatment of bones or joints; Devices specially adapted therefor
  • A61B17/58—Surgical instruments or methods for treatment of bones or joints; Devices specially adapted therefor for osteosynthesis, e.g. bone plates, screws, setting implements or the like
  • A61B17/68—Internal fixation devices, including fasteners and spinal fixators, even if a part thereof projects from the skin
  • A61B17/70—Spinal positioners or stabilisers ; Bone stabilisers comprising fluid filler in an implant
  • A61B17/7001—Screws or hooks combined with longitudinal elements which do not contact vertebrae
  • A61B17/7002—Longitudinal elements, e.g. rods
  • A61B17/7004—Longitudinal elements, e.g. rods with a cross-section which varies along its length
  • A61B17/7008—Longitudinal elements, e.g. rods with a cross-section which varies along its length with parts of, or attached to, the longitudinal elements, bearing against an outside of the screw or hook heads, e.g. nuts on threaded rods
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B17/00—Surgical instruments, devices or methods, e.g. tourniquets
  • A61B17/56—Surgical instruments or methods for treatment of bones or joints; Devices specially adapted therefor
  • A61B17/58—Surgical instruments or methods for treatment of bones or joints; Devices specially adapted therefor for osteosynthesis, e.g. bone plates, screws, setting implements or the like
  • A61B17/68—Internal fixation devices, including fasteners and spinal fixators, even if a part thereof projects from the skin
  • A61B17/70—Spinal positioners or stabilisers ; Bone stabilisers comprising fluid filler in an implant
  • A61B17/7001—Screws or hooks combined with longitudinal elements which do not contact vertebrae
  • A61B17/7002—Longitudinal elements, e.g. rods
  • A61B17/701—Longitudinal elements with a non-circular, e.g. rectangular, cross-section

Definitions

• the present invention relates to an extra-discal intervertebral stabilization assembly for arthrodesis.
• the invention is in the field of arthrodesis, namely bone fusion between at least two adjacent vertebrae. It will be recalled that the arthrodesis aims to allow only micro-movements between the vertebrae, as well as damping vibrations. These micro-movements allow, among other things, the patient, once again bipedal after the operation, to adjust his balance as best as possible before taking the bone graft.
• an extra-discal assembly for arthrodesis within the meaning of the invention, allows an amplitude of movement between two vertebrae, viewed from the side, which is equal to at most about 10% of the natural physiological amplitude.
• the stabilization assembly according to the invention is capable of allowing, at most, a clearance of 1 ° between these two vertebrae. two vertebrae.
• the stabilization assembly according to the invention is intended to connect two adjacent vertebrae, while generally being placed on one side of the spine, namely to the right or left.
• the implantation of this stabilizing element is extra-discal type, namely that it can be located behind, but also in front of the intervertebral space.
• the state of the art known in particular uses plates connecting several vertebrae together, which can be reported on the vertebral bodies according to two main methods of laying.
• the invention aims to remedy these various disadvantages.
• an extra-discal intervertebral stabilization assembly for arthrodesis comprising:
• At least two vertebral screws capable of penetrating into two different vertebrae
• each screw or the connecting member adapted to connect these two screws; one of each screw or the connecting member having a rod, while the other of each screw or the connecting member is provided with at least one eyelet, the walls have a shape, these walls defining an orifice, the or each rod being adapted to penetrate into the or each orifice, with a possibility of displacement in at least one direction of the plane of this orifice.
• the articulation is exerted according to a single point of contact between the stem and the walls of the eyelet; the articulation is exerted according to a contact of flat type on flat, so as to allow a possibility of sub-luxation;
• At least one eyelet has a deformable wall, at least in places, under the effect of an intensity stress much greater than the gravity;
• At least one eyelet is provided with resistance means to the movement of the rod;
• the displacement resistance means comprise a deformable narrowed wall of the eyelet;
• the displacement resistance means comprise a partial filling of the orifice defined by the eyelet, by means of an elastomeric material;
• the connecting member comprises an elongated body, and two sleeves fit to be reported on the body, each sleeve being provided with a corresponding eyelet;
• a first sleeve is fixed relative to the body, while a second sleeve is movable relative to the body;
• At least one spring interposed between the movable sleeve and the fixed sleeve, and / or between the movable sleeve and an end stop of the elongated body;
• the connecting member is formed by a single connecting element having two eyelets, each eyelet being adapted to receive a rod carried by a vertebral screw;
• the connecting member is formed of two separate connecting elements, each connecting element being provided with two eyelets, each rod of a screw vertebral being able to penetrate into two successive eyelets, respectively carried by the two separate connecting elements;
• a first spring is interposed between the movable sleeve and the fixed sleeve of a first connecting element, while a second spring is interposed between the movable sleeve and the end stop of the second connecting element;
• this screw and this eyelet define a free zone not occupied by the rod, this free zone having a dimension, along the main axis of the eyelet, which is greater than or equal to 50%, in particular 100%, of the dimension of the rod, taken along the same principal axis;
• the body of the connecting member has a proper form
• the body is made in one piece; -
• the body is formed of two sections, each of which is provided with a corresponding orifice, while an intermediate element, including damping type, is interposed between these two sections;
• At least one orifice is bordered by an end rim
• At least one orifice is bordered by an abutment wall belonging to a central box;
• the body has a length of between 15 and 45 mm and a width of between 5 and 10 mm;
• each pedicle screw has a rod whose cross section is less than that of the orifice in which it extends, so as to form a game along two directions of the plane of the body of the stabilizing element;
• the rod is provided with at least one elongated head having a length less than the length of the oblong orifice, while being greater than the width of this oblong orifice, whereas the width of this head is less than the width of the orifice;
• the head is formed by a portion of sphere truncated by two flats;
• the rod is provided with a transverse opening adapted to receive a key intended to abut against the walls opposite the oblong orifice;
• the rod is threaded and cooperates with a bolt against which are fit to bear the walls of the orifice;
• the rod of the screw is terminated by a spherical head, the screw being adapted to extend into an orifice formed by a circular main portion extended by two notches;
• the bolt has a head made of a clean damping material to abut against the flange and / or the abutment wall of the extradiscal element;
• the invention further relates to a method for laying the above assembly, in which:
• the at least two vertebral screws are implanted in respective vertebrae
• the or each connecting member is tensioned so that it exerts a corresponding tension force on the vertebral screws. According to other characteristics:
• the at least two screws are implanted in respective vertebrae, so that the distance between the free ends of these screws is different from the distance separating the center of the orifices of the connecting member; then modifying the distance between these free ends, by means of an external action, in particular with the aid of a tool, so that this distance becomes close to the distance between the centers of the orifices; and finally these free ends are introduced through the orifices, then the external action is released so as to tension the or each connecting member;
• a pedicular screw implanted in a first side, right or left, from a first vertebral body to another pedicle screw, implanted in the opposite side, respectively left or right, is connected by means of a transverse connection member; a vertebral body immediately adjacent to said first vertebral body.
• FIGS. 1 and 2 are top views, illustrating an eyelet and a rod belonging to an extra-disc set according to the invention
• FIG. 3 is a perspective view illustrating this eyelet and this rod;
• - Figures 4 and 5 are side views, illustrating the mutual movement between the eyelet and this rod;
• FIGS. 6 and 7 are side views, similar to Figures 4 and 5, illustrating an alternative embodiment of the eyelet
• FIG. 8 to 14 are perspective views schematically illustrating other embodiments of the eyelet
• FIGS. 15 to 17 are graphs illustrating the force as a function of the displacement of the rod, along the eyelet, for some of the preceding embodiments;
• FIGS. 18 to 22 are perspective views, illustrating different embodiments of the rod
• - Figure 23 is a schematic view illustrating the extradiscal assembly, according to the invention, in general; - Figure 24 is a perspective view, illustrating an alternative embodiment of the invention;
• FIG. 25 is a perspective view, illustrating an arrangement which does not form part of the invention
• Fig. 26 is a graph, illustrating the force versus displacement, for the arrangement of Fig. 25;
• FIGS. 27 and 28 are perspective views, illustrating an additional arrangement which does not form part of the invention, in two positions;
• - Figure 29 is a curve, similar to Figure 26, relating to the arrangement of Figures 27 and 28;
• FIG. 30 is a perspective view, illustrating a further variant not forming part of the invention.
• FIG. 31 is a curve, similar to FIG. 26, relating to the arrangement of FIG. 30;
• Fig. 32 is a perspective view illustrating an additional arrangement not forming part of the invention.
• - Figure 33 is a curve, similar to Figure 26, relating to the arrangement of Figure 32;
• - Figure 34 is a perspective view illustrating a further embodiment of the invention;
• FIG. 35 is a curve similar to FIG. 26, relating to the embodiment of FIG. 34;
• Figure 36 is a curve similar to Figure 26, relating to another embodiment of the invention, not shown;
• FIG. 37 is a side view, illustrating a further variant of the invention.
• FIGS. 38 and 39 are perspective views illustrating two further variants of the invention.
• - Figure 40 is a schematic view, illustrating a further embodiment of a rod and an eyelet according to the invention;
• FIG. 41 is a perspective view, illustrating a connecting member belonging to the extra-discal assembly according to the invention
• FIG. 42 is a perspective view, illustrating a pedicle screw adapted to be associated with the member of FIG. 41;
• FIG. 43 to 45 are perspective views, illustrating the fastening of the screw and the connecting member;
• FIG. 46 and 47 are side views, illustrating a first type of implantation of the connecting member according to the invention;
• FIGS. 48 and 49 are side views, illustrating another type of implantation of the connecting member according to the invention.
• FIG. 51 is a rear view, illustrating a further embodiment of the invention.
• FIG. 52 to 54 are longitudinal sectional views, illustrating different profiles of the connecting member according to the invention.
• FIG. 55 is a side view, illustrating another alternative embodiment of this intervertebral connection member;
• FIG. 56 is a perspective view, illustrating another alternative embodiment of a connecting member according to the invention.
• FIGS. 58 and 59 are perspective views, illustrating two different embodiments of a pedicle screw to be associated with a connecting member according to the invention
• FIG. 60 is a perspective view illustrating a further embodiment of the embodiment of the connecting member according to the invention.
• Figure 61 is a longitudinal sectional view, similar to Figure 57, illustrating a further embodiment of the invention.
• FIG. 62 and 63 are views in longitudinal section, illustrating two other embodiments of the connecting member according to the invention.
• Figures 64-66 are perspective views, similar to Figures 43-45, illustrating the mounting of a pedicle screw and a stabilizing element, both conform to a further variant of the invention
• FIG. 67 is a partial sectional view illustrating an alternative to the embodiment of Figs. 64-66; and FIG. 68 illustrates an alternative embodiment of the embodiment of FIG. 24.
• Figures 1 to 3 illustrate the object of the invention, in all its generality.
• the invention can be generalized to the use of two eyelets, one of which is illustrated in these figures, defining two oblong orifices, one of which is illustrated.
• Each eyelet has a proper form, namely that this form is invariant under the effect of gravity, as well as other constraints of similar intensity.
• each eyelet is likely to deform, at least in places, under the effect of constraints whose intensity is much higher than the gravity, as will be described in more detail in the following.
• FIGS. 1 to 3 more particularly illustrate the cooperation of a rod 1018 belonging to a screw 1010, which penetrates into the orifice 1004 defined by the eyelet 1005.
• This screw 1010 is for example a pedicle screw which comprises, in a conventional manner , a threaded zone intended to penetrate into the vertebral body.
• it can be provided to use, not a pedicle type screw, but another type of vertebral screw.
• this screw can be implanted in the vertebral body, either laterally or anteriorly, or in the vertebral body through the pedicle.
• any insertion can be provided which ensures that the screw is securely joined to the vertebra. It is then implanted in the vertebra by a thread and allows to exceed, outside the vertebra, a stud which cooperates with a connecting element, as will be described below.
• This nipple may also be supported by a mechanical member different from a thread, such as for example a clip or hooks placed on the vertebral body and / or the intervertebral bone blades.
• the walls of the eyelet advantageously have a curved profile, seen in cross section, so that the joint thus formed is punctual.
• the corresponding contact point is noted P.
• the stem and the walls of the eyelet always have three degrees of freedom in rotation, one with respect to the other, as is illustrated in particular on FIG. 5.
• FIGS. 4 and 5 also illustrate the relative dimensions of the rod 1018 and the orifice 1004.
• L is the dimension of this orifice, taken along the axis A connecting the eyelet 1005 with the other eyelet , not shown.
• this axis A corresponds to the main axis of the connecting member, connecting the two screws 1010.
• this dimension of the free zone 1020 also allows a possible deflection of the rod to the left, which would occur under the effect of a large amplitude movement of the patient.
• a movement of large amplitude corresponds to a hyperextension while, when the connecting member forms a strut, this movement corresponds to a hyperflexion.
• the rod and the eyelet may have shapes, which are different from those illustrated in the previous figures.
• the rod may have a non-circular section, for example square, rectangular or other.
• the walls of the eyelet can define any suitable shape, for example a circle, an oval, a diamond, or a more complex shape.
• the articulation between the rod 1018 'and the walls of the eyelet 1005' can be achieved by means of a non-point contact of the flattened flat surface type.
• These two flats define a relatively weak contact zone, materialized by the distance d, which allows a possibility of sub-luxation of the rod relative to the walls of the orifice (arrow F).
• a joint which can be likened to that of Figures 4 and 5.
• FIG. 8 to 14 illustrate different possibilities, as regards the shape of the walls of the orifice.
• the body of the eyelet is shown very schematically, in phantom.
• the orifice has an oval shape, while extending along one or other of the main directions of the plane of the eyelet.
• the walls of the orifice of FIG. 14 are turned by a quarter of a turn.
• FIG. 9 illustrates a further variant of the invention, in which at least one eyelet is not rigid, but has a proper shape, according to the definition given above. More precisely, this eyelet 1105 has an end zone 1105i, which is narrowed.
• the rod is likely to move, firstly, in an area of the eyelet which has larger transverse dimensions than this rod, so that this movement operates without effort. Then, in the vicinity of the narrowed area, the movement of the rod is possible, thanks to the deformable nature of the eyelet. However, such displacement occurs against a mechanical resistance, whose intensity can be modulated. This is advantageous because it offers a means of unilateral damping, only thanks to the eyelet as well as its composition and / or its geometry.
• Figures 10 and 12 illustrate an alternative embodiment of Figure 9.
• the end zone of the eyelet is more or less narrowed.
• Figure 11 illustrates a further variant of the invention, similar to that of the previous figure, in which there is an eyelet that does not define a closed loop. Thus, it has a generally oval shape, as well as a small size rupture zone, so as to define two opposite free ends. As in the previous embodiment, in the absence of stress, these two free ends define a narrowed area of smaller transverse dimension than the rod. In this way, when the latter moves, it is likely to separate these two ends against a given resistance, until it comes into abutment against these free ends. Of course, these ends are designed so as not to let the rod out of the inner volume of the eyelet.
• the eyelet may be provided with a spring blade, adapted to pivot around a hinge generally perpendicular to the main plane of this eyelet. Under these conditions, the movement of the rod takes place against a predefined resistance of the leaf spring. Then, when the rod returns to its initial high position, the spring blade also finds its original position.
• Figure 13 illustrates a further alternative embodiment of the invention, wherein one end of the eyelet 1205 is provided with a filler material of elastomeric nature, such as a rubber 1205i. In this way, when the rod moves downwards in this figure, this movement takes place against the resistance given by the elastomeric material.
• Figure 15 is a graph illustrating the force F as a function of displacement, denoted x. In other words, if we assume that the eyelet is fixed, the curve materializes the force required to move the rod along the eyelet.
• FIG. 16 illustrates this same curve, for an eyelet whose one end is rigid, but whose other end offers resistance, according to one or the other of the types described for example in the preceding figures (tapered wall, hinge or material elastomer).
• Figure 17 illustrates a curve relating to an eyelet, the two ends are associated with a means for exerting resistance to the displacement of the rod, as in the right part of the previous graph.
• the associated curve then has a shorter horizontal section than that of the preceding figures, corresponding to the movement of the rod between the two resistant means on either side of the eyelet.
• This horizontal section called “neutral zone”, is extended to the right and left by two sections similar to that of the previous figure, each associated with an asymptote.
• FIGS 18 to 22 illustrate different embodiments of the invention.
• the rod 1018 there is the rod 1018, and different stops 1050 to limit the movement of each eyelet, along this rod. Note that in these figures, the eyelet is not shown.
• a single end stop 1050 is provided. Moreover, in FIG. 20, this single end abutment cooperates with a spring 1060 interposed between this abutment and the walls opposite the eyelet. not represented.
• the end stop may be fixed, or slidably mounted on the rod.
• each stop is made in the form of a plate. However, it can be provided to give one or other of these stops different shapes, namely, for example round, oval or other.
• the connecting member, belonging to the stabilization assembly according to the invention comprises, in all its generality, on the one hand two carnations 1005 such described above and, on the other hand, a median zone 1002 extending between these two eyelets, which is shown schematically in FIG. 23.
• This median zone may be rigid or substantially rigid, or may have a shape own according to the definition given above. It can also be provided that it is a flexible or elastic zone. It is also possible to use a median zone grouping combinations of these characteristics, namely respectively rigid, clean, flexible and elastic.
• FIG. 24 illustrates an advantageous possibility, in which an elongated connecting body 1002, made for example in the form of a rigid tube, is provided.
• Each eyelet 1005 is associated with a connecting sleeve 1006, which can slide around the connecting tube.
• Each eyelet can thus be secured, by any appropriate means, with respect to the tube 1002, with possibility of adjustment in the main direction of the body 1002.
• the distance separating the two eyelets can be adjusted with very high precision in situ, especially by the surgeon at the time of the operation.
• FIG. 25 illustrates a first intermediate arrangement which differs from the embodiment of FIG. 24, in that the 2006 of the sleeves is now free to slide freely relative to the connecting tube 2002, up to a terminal stop 2007 of FIG. the latter, while the other sleeve 2006 'is fixed.
• the curve of the force as a function of the displacement firstly comprises a vertical section corresponding to the abutment of the sleeve sliding against the end of the connecting tube.
• the corresponding curve ( Figure 29) then comprises a vertical section, as in the previous figure, then a horizontal neutral zone, corresponding to the free movement of the rod along the sliding eyelet. If we continue the movement of this rod in the direction of the fixed eyelet, this movement now operates against the spring. Under these conditions, the horizontal neutral zone is extended by a section of exponential pace, associated with an asymptote, of the same type as in the figures illustrating an eyelet having a resistance means (narrowed walls, elastomer ).
• a spring 2010 is interposed between the walls opposite the abutment and the sliding sleeve.
• the corresponding curve ( Figure 31) comprises a horizontal neutral zone, corresponding to the free sliding of the upper sleeve along the tube, between the fixed sleeve and the spring, and free movement of the rod of the free eyelet. Then, we find a section of exponential pace, associated with an asymptote, corresponding to the movement of the free sleeve to the spring.
• Figure 34 illustrates an embodiment, which is in accordance with the invention. It is now assumed, with reference to this figure, that the connecting member is no longer formed of a single connecting element, as in the various embodiments above, but two connecting elements 3002 and 4002. In other words, these two connecting elements define four eyelets 3005, 3005 ', 4005 and 4005', each rod 1018 and 1018 'penetrating successively through two of these eyelets.
• each rod abuts, on the one hand, against the first side of the walls of the eyelet of the first element and, on the other hand, against the opposite side of the walls of the eyelet of the second element.
• the associated curve not shown here, consists of a single vertical section, coincident with the ordinate axis. This embodiment, not shown, has certain advantages insofar as it brings a hyperstability to the connection between the two vertebrae that it connects.
• each connecting element has a fixed sleeve and a sliding sleeve, as in the embodiment of FIG. 25.
• the first connecting element is associated with a spring 3008 interposed between the two sleeves 3006 and 3006 '.
• the second connecting element is associated with a spring 4010 interposed between an end stop and the sliding sleeve 4006.
• the curve of FIG. 35 does not have a horizontal section, or neutral zone.
• any mutual movement of the rods occurs in opposition to a resistance.
• the elimination of the neutral zone can be a therapeutic axis, very favorable for the patient, as part of the arthrodesis.
• Fig. 34 it is possible to set different parameters in order to provide varying resistance characteristics. These different parameters include the distance between the two fixed and sliding sleeves, or the stiffness of the springs. Since the invention is in the context of arthrodesis, these springs are chosen as having a high stiffness, so that the two asymptotes of the curve of FIG. 35 are close to the vertical axis of the ordinates.
• FIG. 34 Different variants, not shown, can be provided in the arrangement of FIG. 34.
• at least one of the two springs or even the two springs can be removed.
• the sleeve which is no longer associated with a spring, is fixed on the connecting element.
• the assembly is rigid in a first direction, while it allows a damped movement in the other direction, against the single spring.
• the two springs so that all the eyelets are fixed, the corresponding mount is then hyperstable.
• the springs may be replaced by similar elements, such as rubber pads, slidable on the connecting element.
• a sleeve when movable relative to a connecting element, it is advantageous to provide that it has a reduced axial dimension, in the manner of a ring.
• this ring advantageously has an inside diameter, which is greater than the outer diameter of the connecting member, which allows easier sliding capable in particular to adapt to the bending of the connecting tube.
• Figure 36 illustrates an advantageous variant of the invention, based on the arrangement of the preceding figures.
• a suitable biasing means such as an assembly formed by a nut and a counter-nut, which makes it possible to confer a variable value on this prestressing.
• this nut and this lock nut can be screwed or unscrewed, along the spring stroke.
• each spring is associated with a respective preload value.
• the curve does not have a horizontal neutral zone in some figures, but a vertical zone called stable zone ZS.
• the amplitude of this stable zone corresponds to the intensity of the force that each rod must exert, in order first to overcome the preload associated with the respective springs before being set in motion.
• this stable zone ZS is divided into two sections ZSi and ZS 2 , each of which is relative to a respective spring. Since each spring can be associated with a variable preload, the amplitude of each section ZSi and ZS2 can therefore be adjustable as needed.
• the so-called median zone 1002, connecting the two eyelets may also be of the "external" type.
• this zone encompasses, or incorporates, the two eyelets. It is also possible to use a mixed type connection, namely that this zone includes a single eyelet on one side.
• FIG. 37 illustrates a further variant embodiment of the invention, in which the connection zone 1102 is formed by several elements. There is thus a first spring blade 1102i, said inner, in that it extends between the adjacent ends of the eyelets 1105.
• the connection zone also comprises an outer spring blade, or peripheral 11022, which extends to outside both the first spring blade and the two eyelets.
• the mechanical connection between the two leaf springs is carried out by any appropriate means, for example by a transverse collar 1102 3 . It may further be provided to fill, for example by means of a damping material, the spacer spaces between the inner spring blade and the outer spring blade.
• the embodiment of this FIG. 37 is advantageous in that it makes it possible to create a single object which acts in two opposite directions, which can be prestressed. This embodiment also allows the possible creation of a neutral zone, according to the geometry that will have been chosen for the orifices.
• the rod belongs to the screw, while the eyelet belongs to the connecting element.
• the eyelet belongs to the screw
• the connecting element is provided with the rod.
• Figure 38 where there is a screw 610, extended by an eyelet 605, defining an orifice 604.
• a rod 618, extending the connecting member 602 penetrates floating in this orifice.
• this rod is bordered by a shoulder 619, whose curved profile is likely to cooperate with the walls of the orifice. Under these conditions, during the tensioning, this shoulder comes into contact with the walls of the orifice, allowing mutual articulation of the screw relative to the connecting element.
• this shoulder is placed on the same side of the connecting element, with respect to the eyelet, so as to limit an intervertebral approach movement.
• the shoulder is placed opposite the connecting element, relative to the eyelet, which limits an intervertebral extension movement.
• Figure 40 illustrates a further alternative embodiment of the invention.
• this eyelet may belong either to the connecting element or to the vertebral screw while the rod belongs, respectively, to the vertebral screw or the connecting element.
• the respective dimensions of the orifice and of the stem are such that, in the plane of the eyelet, there is only one degree of mutual freedom in translation, in a single direction corresponding to the main direction of the eyelet which thus forms a slide.
• the rod and the eyelet are linked in translation, in the direction perpendicular to this main direction, namely from top to bottom in FIG. 40.
• FIG. 41 illustrates a particular embodiment of the invention, in which the connecting member is a plate of substantially rectangular shape, designated as a whole by reference numeral 2.
• L, ⁇ and e respectively denote the length, the The width and thickness of this plate 2.
• L is 15 to 45 mm, 5 to 10 mm, and e is 1 to 8 mm.
• the main longitudinal axis of this plate is noted.
• This plate 2 has a proper shape, which means that it is likely to keep the same geometry in the absence of external constraints, especially under the effect of gravity alone.
• the geometry of this plate does not vary substantially during the usual constraints to which it is subjected, once implanted on the patient.
• this plate can be completely rigid, in which case it is for example made of metal. It may, however, have a slight flexibility, similarly to the plate described in US-A-4,743,260. In this case, it is for example made of a plastic material, polymer, or composite comprising fibers such as fibers. of carbon.
• the plate 2 is hollowed out with two oblong orifices 4 whose main axis corresponds to that of the plate.
• L 'and T denote the length and the width of these orifices and the distance separating the center from the two orifices 4. Given their construction, the length L' of these orifices is greater than their width V.
• the shape of this plate does not constitute such a characteristic, since this shape can be variable according to many parameters, in particular of anatomical type.
• the plate may for example have a form of banana, arc, or an angled shape. This is also shown in Figure 55, where the plate 2 has a bend, noted 3.
• Figure 42 illustrates a pedicle screw 10, intended to cooperate with the plate 2 described above.
• This screw 10 comprises, in the usual way, a threaded zone 12 intended to penetrate into a not shown vertebral body.
• this screw can be implanted in the vertebral body, either laterally or previously, it is then implanted in the vertebral body by a thread and allows to exceed, outside the vertebra, a stud which cooperates with a connecting element as will be described below.
• This stud can also be supported by a mechanical member different from a thread, such as for example a staple or hooks placed on the vertebral body and / or intervertebral bone blades.
• the zone 12 is extended by a cylindrical shaft 14, which ends with a shoulder 16, from which extends a rod 18 of smaller cross section.
• This rod 18 is extended by a head 20, which is formed by a sphere portion 20i truncated by two flats 2O2.
• This head is further provided, in a conventional manner, a footprint 2O3 for cooperation with a not shown tool, for the purpose of placing the screw 10 in a vertebral body also not shown.
• L the length of the head, which therefore corresponds to the diameter of the spherical portion 20.
• This length L" is slightly less than that L 'of the orifice 4, while being significantly greater than the width T of this orifice.
• the width T of this head 20 is slightly less than the width V of the orifice 4.
• FIGS. 43 to 45 illustrate the positioning of each screw 10 with respect to the plate 2. This is all about first place the head 20 in the axis of the orifice 4, then bring the plate according to the arrow fi, to penetrate the head through the orifice. This operation is possible, since, as seen above, the length and the width of the head are slightly smaller than those of the orifice 4.
• the mutual attachment of the plate 2 and the screw 10 is of the "loose" type, that is to say that it is accompanied by operating clearances, at least in the absence of external tension exerted on the plate and on the screw.
• the plate 2 is mounted "floating" on the screws 10, in the absence of such a voltage.
• the rod 18 has dimensions smaller than those of the orifice 4, there is a clearance according to the two main dimensions of the plate, corresponding to its length and width.
• this plate can move slightly between the head 20 and the vertebral body opposite.
• Figures 52 to 54 illustrate more precisely the walls of the oblong orifices 4. It is noted that these walls are rounded, having a concavity directed away from these orifices.
• the walls 4i are formed directly in the body of the plate, namely that no insert element is provided.
• the walls 42 and 4 ⁇ are formed by inserts in the plate body.
• these elements may be made of a material different from that constituting the remainder of the plate, in particular of a metallic material. This element is then subjected to the edges facing the plate by any appropriate means, for example by crimping.
• the rounded profile of the walls 4 1 and 4 2 is substantially symmetrical with respect to a median axis of the plate, in this case horizontal.
• the walls 4 ⁇ may be asymmetrical with respect to such a median axis.
• the respective profiles of the walls of the orifices 2, as well as of the head 20, are such as to enable the plate to be swiveled with respect to the screw, when the latter takes support against the walls of these orifices.
• the screw when the screw is supported by its head 20 against the walls of the orifices 2, there is at least one, in this case three degrees of freedom in rotation between the plate and the screw, according to a movement angular on the order of at least 15 degrees.
• Figures 46 and 47 illustrate a first variant, with regard to the installation of the plate 2, which is intended to form in this case a stay.
• the first step is to place two screws 10 in two adjacent vertebral bodies, denoted ⁇ ⁇ and V 2 . According to this first mode, the distance separating the free end of the screws 10 is greater than that separating the centers from the orifices 4.
• the plate 2 exerts forces F 1 and F 2 on the rods 18 of the screws 10. Under these conditions, the plate 2 thus tensioned forms a stay, which opposes the kyphosis setting of the patient. , namely intervertebral flexion.
• This guying which engages the articular facets in one another and which puts in tension the anterior part of the disc and the anterior ligament vertebral, is stabilizing for the intervertebral articulation.
• Figures 48 and 49 illustrate a variant of installation, wherein the plate 2 now provides a forestay function. Contrary to what has been described above, the screws 10 are now implanted in the vertebral bodies ⁇ ⁇ and V 2 , so that their distance d_ "is less than the distance d_ separating the screws 10. mutually to distance these screws 10, for example by means of a tool, so as to increase the value of d "until it is close to d. Then, proceed as explained above, so as to secure the two screws 10 and the plate 2.
• Figure 50 illustrates a further variant embodiment of the invention, using two plates 2 'and 2 ", extending over two vertebral stages, for which purpose two screws 10' and 10 are first provided. Similar to those described above, which are implanted in the end vertebrae ⁇ and V 2 .
• a median screw 110 is implanted in the intermediate vertebra V 3 .
• This screw 110 is provided with two heads 120 'and 120 ", arranged one behind the other.
• the cooperation of the plates 2 'and 2 "with the end screws 10' and 10" is similar to that described above.
• the plate 2 ' is interposed between the barrel 118 and the first head 120', with the existence of three functional games as mentioned above.
• the second plate 2 is interposed between the two heads 120 'and 120" of the central screw 110, with also the existence of functional play in the three directions of space.
• Figure 57 illustrates a variant of the embodiment of the invention, wherein there are two plates 2i and 2 2 between two same pedicle screws 110i and 110 2 , which are for example similar to the median screw 110 described above.
• each of these screws 110i or 110 2 has two truncated spherical heads, 12Oi and 12O'i respectively, and 12O 2 and 120 ' 2 .
• the first plate 2i is placed in the forestay position, as illustrated in FIG.
• the second plate 2 2 is placed in the guying position, as illustrated in FIG. 47.
• the placement of these two plates takes place first of all by placing the first of these plates, forming a strut, as described in the references to Figures 48 and 49. Then, we bring the free end of the two screws from each other, so as to allow the force passage of the second plate, forming stay.
• FIG. 57 is advantageous because it offers hyper-stability during assembly, without, however, inducing high stresses on the pedicle screws.
• the effectiveness of the stay is doubled by a lever effect, insofar as the forestay initially set up serves as a fulcrum and allows the stay to complete its effect of an arm of leverage which exerts on the bone part of the implant. This improves the setting of vertebral lordosis, as well as the stability of the intervertebral joint.
• the two screws 11O1 and HO2 have only two truncated spherical heads. However, it can be provided to equip one and / or the other of these screws by means of three such heads.
• Figure 50 illustrates the connection between three adjacent vertebrae. It is naturally possible to connect a greater number of vertebrae, by means of different plates according to the invention. In addition, provision may be made to use, for the connection between two adjacent vertebrae, two plates placed on the left and on the right, namely on either side of a median vertical axis, with reference to the patient in a standing position.
• the invention concerns not only a plate 2 as such, namely an extra-discal intervertebral stabilization element, but also a set of such plates. Indeed, during the operation, the surgeon has several plates of different lengths, for which the distances between the orifices 4 are also different, proportionally. Thus, depending on the intervertebral stage to be equipped, as well as the pathology to be treated, the surgeon will be able to choose the appropriate inter-orifices spacing. This spacing corresponds to the distance referenced in particular in FIGS. 41, 46 and 48.
• the plate 2 ' comprises a turnbuckle 5, which cooperates with two rods 7i and 7 2 themselves terminated by extensions 9i and 9 2 , in each of which is formed a corresponding oblong hole 4io or 4 2 o .
• the invention relates to an intervertebral stabilization assembly which comprises at least one plate 2, 2 'and / or 2 ", and at least two pedicular screws adapted to cooperate with the or each plate.
• FIG. 51 illustrates a further variant of embodiment, having particular application to the case of instability due to the absence of an articular facet, and thus to a plate 52 extending from one side to the other.
• the plate has two end ports 54, allowing it to cooperate with pedicle screws 6O1 and 6O2, as described above with reference to the first embodiments.
• the plate 61 connects the screws 6O1 and 60 ' 2
• the plate 61' connects the screws 6O'i and 6O 2 , as described above, with reference to the first embodiments.
• This plate 52 advantageously comprises a central articulation 53, made by any appropriate means, which gives the plate an angulated shape, know protruding backwards.
• This articulation also makes it possible to define the distance between the orifices, while being able to be locked in a rigid manner when the shape and the position are obtained.
• Such a cross plate can be put in place by forming a stay.
• two thus articulated plates one of which forms a stay and the other forms a strut, in the case of treatment of complex deformations, such as rotational intervertebral dislocations.
• the different plates can be tensioned in the direction of the guying, as shown in Figure 47. Under these conditions, all of these plates tends to oppose the patient's intervertebral flexion.
• Figure 58 illustrates an alternative embodiment of the invention, relating to the structure of the pedicle screw.
• the latter which is assigned reference 210, differs from that 10, in that it has no head 20.
• it has a rod 218 adapted to penetrate into an orifice 4 of the plate 2, while being dug a transverse opening 219, allowing the passage of a key 220.
• FIG. 59 A further variant embodiment of this pedicle screw is illustrated in FIG. 59, in which the rod 318 of this screw 310 forms a stud 319, which is adapted to cooperate with a bolt 320.
• FIGS. 8 there is also the presence of functional clearances, in the three directions of space, between the screw 210 or 310 and the walls opposite the plate 2.
• FIG. 60 illustrates a further variant embodiment of the stabilization element according to the invention, which is designated as a whole by the reference 102.
• This element comprises a rigid body, formed by two plate sections 102 1 and 102 2 , each of which is made for example in the same material as that constituting the plate 2 of the first embodiment. Moreover, the sections are dug two oblong holes 104i, 104 2 , which are similar to those 4 of the first embodiment.
• damping pad 103 made for example of elastomer or any other equivalent material.
• a buffer may be replaced by an equivalent damping member, such as a spring.
• FIG. 61 illustrates an advantageous variant of the invention, using two plates 102 'and 102 ", similar in structure to that 102 of FIG. 60. These two plates extend on two same pedicle screws, respectively forming a stay and a stay, as explained in figure 57.
• the buffer 103 'of the plate 102', forming strut can be made to work only in compression, while the other buffer 103 ", equipping the plate 102" forming stay, then works only in extension. In this way, two different dampers are used, each of which works in a single direction. This allows for very simple dampers and, therefore, economically advantageous.
• only one of the buffers is double-acting, the other being single-acting.
• FIG. 62 illustrates a further alternative embodiment of the stabilization element according to the invention, which is designated as a whole by the reference 202.
• This element firstly comprises a rigid body 202i, having a similar plate shape 2 of Figure 1.
• This plate 202i is extended by at least one, in this case two end flanges 2022, which extend substantially perpendicularly to the plane of the plate 202i.
• Each screw 410 includes a rod 418, whose free end is threaded so as to cooperate with a ball 420, hollowed with a threaded bore adapted to cooperate with this thread.
• each rod 418 is introduced through a corresponding orifice 204.
• each elastomeric ball 420 which allows the retention of the element 202, is screwed, since each ball has a diameter which is greater than the dimensions of the orifice 204, at least as regards the width of the latter.
• Each ball 420 which is made of a damping material, such as an elastomer, is capable of abutting against the walls facing the flanges 2022.
• This embodiment is advantageous, insofar as the presence of the balls 420 allows to dampen the different movements to which is subjected the binding assembly according to the invention.
• This plate is intended to limit a movement to a selected rotation sector, while allowing a damped end of movement.
• FIG. 63 illustrates a further alternative embodiment of the invention.
• the mechanical elements similar to those of Figure 62 are assigned the same reference numbers, increased by 100.
• a stabilizing element comprising a plate
• the damping balls 520 are therefore capable of coming into abutment, either against the flanges 3022 as in the case of FIG. 62, or against the walls 302 4 of the intermediate box.
• the amortization thus conferred is therefore exercised in two opposite senses.
• This embodiment allows to choose a free movement in an advantageous sector of rotation, while ending the movement by cushioning at each end.
• the box 302 3 it is possible for the box 302 3 to extend axially over a shorter distance, so that it forms a single stop wall for a single damping ball 520.
• the another pedicle screw is for example similar to that 10, 210 or 310 of the previous figures.
• FIGs 64 to 66 illustrate a further variant of the invention.
• the pedicle screws 610 are similar to those 10, except as regards the shape of their head 620. Indeed, the latter is spherical, without being truncated by flats as in particular in Figure 42.
• each oblong hole 404 of the plate 402 comprises a main portion 404i, substantially defining a circle whose diameter is slightly greater than that of the head 620. This median portion is extended by two axial notches, or ears 404 2 , s' extending on either side of the median portion 404i along the main axis of the plate.
• FIG. 67 represents one of the possible arrangements, involving a screw 710, similar to that 610 of FIG. Figures 64 to 66, which has several spherical heads 720i, 72O 2 and 723.
• This screw is further provided with a first rod 7181, as well as two intermediate rods 7182 and 7183.
• first plate 402i in the vicinity of the not shown vertebral bodies, which is mounted to form a strut.
• second plate 402 2 connecting the same pedicle screws that the first plate, which is mounted to form a stay.
• a third plate 402 3 extends from the pedicle screw 710 to another screw, not shown, belonging to another intervertebral stage. This arrangement provides a possibility of articulation, in the three dimensions of space, of each plate relative to the screw.
• the same vertebral stage is connected by both an anterior connecting element and a posterior connecting element.
• one of these elements form was and the other form stay, during a first type of movement of the patient while, when the patient exerts the opposite movement, the one guy form and the other form prop.
• the rigid tube 1002 connects the two connecting sleeves 1006 at the same side of the eyelets 1005, in this case to the left of the latter in the figures.
• this tube extends obliquely, namely between a first lateral side of a first eyelet and the opposite lateral side of the second eyelet.
• the state of the art is first of all a monobloc type of fastening between the pedicle screws and the plate that connects them. Under these conditions, the pulling and bending forces exerted on the plate, once implanted, are directly transmitted to these screws which tend to move relative to the vertebral body. These high stresses are more particularly exerted on the pedicular screws, which are at the ends of the assembly.
• the plates of the prior art are regional, namely that one plate connects more than two vertebral stages.
• the Applicant has found that such a provision does not provide a satisfactory solution for positioning the vertebrae relative to each other.
• the surgical fixtures are, by nature, intended to stabilize the spine in good position. Such stabilization then makes it possible to obtain an appropriate bone fusion, called arthrodesis.
• a favorable position, in particular a lordosis, allows a satisfactory economy of the erected human position, which results in a physiological muscular work, free from contracture type dysfunctions.
• the present invention makes use of functional clearances between the screws and the connecting element. This makes it possible to obtain an articulation between these screws and this element, which avoids the mechanical stress at the screw / bone interface.
• the intervertebral joint does not have a single center of rotation, but a cloud of centers of rotation.
• the reproduction of the physiological articulation requires considering a plurality of instantaneous centers of rotation, rather than a single permanent center of rotation.
• the joint recreated by the invention has more mechanical abilities to accompany the vertebral movement, a joint having a single fixed center of rotation, as in the prior art presented above.
• the spine has a plastic quality of permanent equilibrium search, so that these centers of rotation are likely to evolve to the son of the patient's life, due to the deformation of the components of the column. This requires not to impose a rotation center a priori. Indeed, if this is the case, this would create a conflict, which would be a source of iatrogenic pathology.
• the present invention relies advantageously on the concept of segmentation.
• the same plate connects only two adjacent vertebrae, which allows a more effective treatment of different pathologies.
• the use of several successive plates makes it possible to confer a sufficient degree of lordosis, which is not found in the prior art using a single plate.
• the advantageously segmented assembly of the invention allows in particular to obtain, by choice of inter-pedicle distance, the value of the exact lordosis that is sought.
• each intervertebral joint is considered as such, and treated according to its own characteristics, this all along the spine.
• the stabilization assembly for arthrodesis allows a rotational clearance, between two vertebrae, less than or equal to about 10% of the natural physiological movement.
• the different embodiments presented above can be separated into two categories. Thus, we find first mountings that allow no rotational movement between the two vertebrae they connect.
• stage L 4 -L 5 with an arthrodesis assembly allowing a certain angular deflection, and the L 3 -L 4 stage with a prosthesis.
• scoliosis In the case of scoliosis, can be fitted floors D12 L 4 with a hyperstable arthrodesis assembly, stage L 4 -L 5 with an arthrodesis mounting low angular travel, and finally the stage L 5 -Si, either with a prosthesis assembly, or with an arthrodesis assembly allowing a small displacement.
• These two different assemblies are for example two arthrodesis assemblies according to the invention, one of which is hyperstable and the other of which allows a low angular deflection.
• a first assembly corresponds to a prosthesis, while the other assembly is arthrodesis type, with or without angular movement possible.

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• Health & Medical Sciences (AREA)
• Orthopedic Medicine & Surgery (AREA)
• Life Sciences & Earth Sciences (AREA)
• Surgery (AREA)
• Neurology (AREA)
• Heart & Thoracic Surgery (AREA)
• Engineering & Computer Science (AREA)
• Biomedical Technology (AREA)
• Nuclear Medicine, Radiotherapy & Molecular Imaging (AREA)
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• 2008
  • 2008-05-06 FR FR0802509A patent/FR2930886A1/fr not_active Withdrawn
  • 2008-05-06 FR FR0802508A patent/FR2930885B3/fr not_active Expired - Fee Related
  • 2008-07-23 US US12/452,823 patent/US20100131010A1/en not_active Abandoned
  • 2008-07-23 EP EP08826759A patent/EP2182869A2/de not_active Withdrawn
  • 2008-07-23 WO PCT/FR2008/051388 patent/WO2009016318A2/fr active Application Filing
• 2009
  • 2009-05-06 WO PCT/FR2009/050839 patent/WO2009141567A1/fr active Application Filing

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