Classifications

• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B17/00—Surgical instruments, devices or methods
  • 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 or setting implements
  • 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, e.g. stabilisers comprising fluid filler in an implant
  • A61B17/7049—Connectors, not bearing on the vertebrae, for linking longitudinal elements together
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B17/00—Surgical instruments, devices or methods
  • 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 or setting implements
  • 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, e.g. stabilisers comprising fluid filler in an implant
  • A61B17/7049—Connectors, not bearing on the vertebrae, for linking longitudinal elements together
  • A61B17/7052—Connectors, not bearing on the vertebrae, for linking longitudinal elements together of variable angle or length

Definitions

• the present invention relates to a frame for stiffening a bone or set of human or animal bones.
• the present invention finds a preferred application during osteosynthesis operations of the spine vertebrae and arthrodesis with osteosynthesis of spine joints. It also finds other applications in restorative surgery of bones and joints.
• a stiffening frame intended for arthrodesis of one or more spinal joints comprises, in general, two plates fixed on either side of the spine and on either side of the joint considered. These plates, which have a shape and, in particular a bending adapted to the shape and the curvature of the zone considered of the spine, are joined transversely by means of two bridges or crosspieces screwed onto these plates, so as to constitute a rigid frame. In this way, the joint considered is stiffened and a natural calcification process leading to the welding of the two vertebrae considered (arthrodese) can then take place.
• This frame can be removed during a second operation, if the arthrodesis is successful.
• the present invention overcomes the above drawbacks and solves the problem posed because it aims at a framework for stiffening a bone or set of bones, such as the spine, of the kind comprising two plates intended to be fixed from one side and the other of a bone or set of bones considered and at least two crosspieces intended to secure the plates to one another in the transverse direction, so as to constitute the frame, the plates having a shape, and in particular a bending, generally adapted to the bone or set of bones considered, characterized in that each crosspiece comprises at least one mounting section comprising a concave mounting surface, while each plate comprises at least one mounting stud, having a convex mounting surface, the mean radius of curvature of which is equal to or smaller than that of said concave surface, so that the convex mounting surface of the stud is able to cooperate with the surface co mounting cross member.
• the mounting stud has a spherical convex mounting surface, while each crosspiece comprises at minus a concave toroidal mounting surface, capable of cooperating with the spherical mounting surface of the studs.
• the surgeon has a stiffening frame that is much easier to implant. Indeed, thanks to the cooperation of the convex surface of the mounting studs with the concave surface of the crosspieces, the surgeon has a certain freedom of implantation because the mounting surfaces of the studs of the plates and of the crosspieces can be moved l '' in relation to each other in the longitudinal and / or transverse direction, while their orientation in relation to each other, in relation to the three axes of rotation, can vary within limits determined by the convex and concave geometries considered. In the preferred embodiment, said mounting surfaces are ridged.
• the streaks help prevent accidental movement of a crosspiece relative to the plate on which it is secured, and contributes., thereby, to the good performance of the assembly over time.
• the mounting stud has a threaded hole, opening into said mounting spherical, capable of cooperating with a locking screw.
• the concave mounting surface of the cross member extends generally along a predetermined axis, the mounting section of the cross member comprising a oblong mounting opening extending along said axis and passing through said concave mounting surface.
• the present invention also makes it possible to solve another problem which arises for surgeons when implanting frames of the state of the art referred to above.
• the sleepers of the state of the art consist essentially of cylindrical rods.
• the thorny spine When a thorny spine is placed across the passage of a rod, taking into account the optimal implantation of the plates chosen by the surgeon, the latter must either perforate. the thorny, either proceed to cut it, which is not without presenting various drawbacks for the patient.
• this aspect of the operation is particularly delicate to implement because of the structure of the frames of the prior art.
• the present invention overcomes this drawback by proposing a cross member having an openwork intermediate part to allow the passage of the thorny.
• the aperture results from the conformation of the intermediate part of the crosspiece, in a horseshoe, so as to allow the passage of a thorny spine.
• the frame according to the invention can also be used in other orthopedic restorative surgery operations. It can thus be used in particular for blocking certain joints such as the hip, knee or elbow.
• the present invention also relates, on the one hand, to a plate and, on the other hand, to a cross member for a stiffening frame having the characteristics succinctly set out above.
• FIG. 1 is a plan view of a frame according to the invention, located on the lower part spine,
• FIG. 2 is a sectional view along the axis II - II of FIG. 1
• FIG. 3 is a detail view of the mounting surface of the cross member illustrated in FIG. 1, the cross member being turned over,
• FIG. 4 is a partial perspective view of the frame illustrated in Figure 1
• FIGS 5a, 5b are detail views showing the cooperation of a mounting pad with the mounting surface of a cross member, allowing adjustment the range of the plates relative to an axis, and
• FIG. 6a and 6b are detail views showing the cooperation of a mounting pad with the mounting surface of a cross member for adjusting the position of the plates relative to another axis.
• the embodiment chosen and described in support of Figures 1 to 4, of the frame according to the invention, is intended to stiffen the lumbo-sacral hinge of the spine.
• the frame 20 comprises, here, a plate 21 and two crosspieces referenced at 22, 23. It is observed that crosspieces 22, 23 have a different transverse dimension, so that the plates 21, which are identical, can advantageously take an orientation oblique to each other, so as to be implanted in the appropriate places of the sacrum S1 and the lumbar vertebrae L3, L4 and L5.
• the plates 21 have a shape, and in particular a bending visible in Figure 2, adapted a. the general geometry of the three lumbar and sacrum considered. In other embodiments, the plates 21 may have another bend, or even be rectilinear, taking into account the vertebrae or the bones on which they are intended to be implanted. Optionally, these plates can be made to measure, taking into account the spinal geometry and other particulars of the patient to be operated on.
• the plates 21 comprise several series of openings 24, having a shape resulting from the longitudinal juxtaposition of several intersecting holes, so as to allow the passage of fixing screws 25, intended to secure the plates with the vertebrae concerned or the sacrum.
• These screws called pedicle screws, are intended to be mounted, in a manner known per se, in the pedicle of the vertebrae, with an orientation such that the vertebral canal is not reached.
• the lights At the level of the sacrum, the lights have the form of simple holes 28.
• each crosspiece 22, 23 comprises at least one mounting section 35 comprising a mounting surface 30 of concave shape (not visible in FIG. 1), while each plate comprises at least one mounting pad 40, itself comprising a convex mounting surface 41, the mean radius of curvature of which is equal to or smaller than that of the concave surface 30 ( Figures 3 and 4).
• the mounting surface 30 is a toroidal concave surface, substantially symmetrical with respect to a so-called "transverse" axis, parallel to the largest dimension of the crosspieces and bearing the reference 31 in the figures.
• the mounting surface 41 of the mounting studs 40 is substantially spherical in this embodiment, the radius of the sphere being substantially smaller here than the smallest radius of curvature of the toric surface 31.
• Each plate here has two mounting pads
• the mounting surface of the mounting section or sections of the sleepers is a concave surface which can have various geometric shapes. In the preferred embodiment, it has been seen that it is toroidal, and symmetrical with respect to the transverse axis 31; it can have any other concave shape. It can thus be, for example, a surface resulting from the spatial displacement of a portion of a concave generating plane curve, preferably circular or elliptical, parallel to itself along an epi-cycloidal guiding curve, the direction of the generatrices being generally perpendicular to that of the directing curve. It can also be spherical.
• each mounting stud 40 has a tapped blind hole 42 opening into the convex surface 41, capable of cooperating with a locking screw 43.
• the O-ring mounting surfaces 30 associated with each cross member 22, 23 extend generally along the transverse axis 31.
• Each mounting section 35 of the cross members 22 , 23 comprises an oblong opening 33, which extends along the axis 31, and crosses the toric surface 30. These oblong openings have a width substantially greater than the diameter of the body of the locking screws 43.
• the mounting surfaces 30 and 41 are ridged, the ridges on the convex mounting surface 41 of the pads 40 being of substantially radial orientation, while those of the surface mounting toroid 30 having an orientation substantially perpendicular to the transverse axis 31.
• the studs have a height of the order of 7 mm in the embodiment chosen and shown.
• the surgeon begins by fixing the plates 21 by means of pedicle screws 25, as illustrated in Figure 1.
• the position of the plates is determined by the surgeon in accordance with the geometry of the vertebrae, so as to have the best possible support of the plates 21 on the lumbar vertebrae as well as on the sacrum.
• the surgeon does not have to look for supports for the plates belonging to the same cylindrical surface whose director would correspond to the bending of said plates.
• said mounting surfaces can cooperate so that the cross member can be moved relative to the plates, keeping between the mounting surfaces concerned an at least "linear” contact. Indeed, the contact between the mounting surfaces is made at least along a portion of the curve and not punctually, which gives a good quality temporary support, at least during the mounting of the locking screws.
• this portion of the curve is materialized, on the side of the concave mounting surface of the crosspieces, by one of the striations of orientation perpendicular with respect to the axis 31, and, on the side of the convex surface of the studs, by two radial ridges, being at this moment opposite the considered rib of the concave mounting surface of the crosspiece. It is the same on each of the studs with which the cross member under consideration cooperates (22 or 23).
• the various elements of the frame, including the pedicle screws are made of pure titanium in accordance with the AFNOR T 40 standard. This metal has qualities well known in surgery restorative and it is relatively soft.
• the titanium constituting the crosspiece or the plate can be chosen so that it is harder than the other element, which makes it possible to promote the interpenetration of the striations during the tightening time, the hard edges of the striations penetrating. relatively easily in the material constituting the ridges of the streaks of the other element made of softer metal. The locking of the elements during the delicate clamping operation is thus even better ensured.
• a relative displacement of the crosspiece 22 or 23 relative to the plates 21 in the direction of the axis 31 can also take place within limits imposed by the length of the oblong openings 33.
• Figures 5a and 5b illustrate among other things this adjustment.
• the concave (toric here) and convex (spherical here) geometries of the mounting surfaces 30 and 41 allow angular deflections in the three directions between the crosspieces 22, 23 on the one hand, and the plates 21.
• the crosspieces 22, 23 can assume almost any angular position around the axis of the locking screws, no theoretical limit being imposed in this embodiment on this adjustment.
• the crosspiece can take relative to the plate various angular positions relative to the other two axes of rotation, which in reconstructive surgery, especially of the spine, is particularly important.
• FIGS. 3 and 4 show diagrammatically in FIGS. 3 and 4 by the arrows in thin lines bearing the reference 50.
• This rotation is illustrated at the level of the mounting portions 35 of the crosspieces and the mounting pads 40 by FIGS. 5a and 5b. Indeed, these figures illustrate not only the possibility of adjusting the position transverse of the crosspieces, but also the rotation 50. Two positions of the mounting pads relative to the mounting surface of the crosspieces are illustrated.
• FIGS. 6a and 6b illustrate this rotation since they show the cooperation of the convex surface 41 with the concave surface 30 allowing to perform the angular adjustment in the direction of the arrow 51. It can be seen that this adjustment is independent of the adjustment of the longitudinal position of the crosspiece relative to the plate illustrated in these same figures, this independence resulting from the convex geometries (here spherical) and concave (here toroidal) of the mounting surfaces 41, 30 respectively of the stud 40 of the plate 21 and of the section 35 of the crosspieces 22, 23.
• the geometry of the frame 20 is in no way fixed once and for all, but can vary in three dimensions, within the limits imposed by the geometry of the mounting surfaces, and, when the fixing of the plates to the crosspieces is made by means of locking screws, by those of the diameter of the body of the locking screw on the one hand, by the two main dimensions of said oblong openings.
• the toroidal shape of the mounting surface 30 disposed at each end of the crosspieces 22, 23, was chosen, in this embodiment, taking into account its minimal bulk in a direction perpendicular to the transverse axis 31, and the possibility to have a surface developing along a relatively large length, in the direction of the axis 31.
• the mounting surface 30 has a dimension, in the direction parallel to the axis 31, which is 17 mm, while in the transverse direction relative to the axis 31, this dimension is of the order of 1 cm.
• the radii of curvature of the toric surface are: in the direction of the axis 31: 20 mm, in the direction transverse to this axis: 6.5 mm.
• the convex surface associated with the mounting studs is spherical.
• the present invention solves another problem which has arisen for surgeons with sleepers of the state of the art. Indeed, it was recalled in the preamble to the present application that these sleepers required either the drilling of a thorny, or the cutting thereof; when the latter is on the passage- of a crosspiece.
• the present invention overcomes this drawback by proposing sleepers comprising a portion 60 having an aperture. That is carried out, here, by conforming the portion 60 in horseshoe, which thus constitutes a housing 62, here of 15mm of depth, making it possible to accommodate the thorny 61, in the hypothesis where the axis 31 crosses this thorny. This characteristic is illustrated in particular at the level of the vertebra L4 in FIGS. 1 and.
• Other advantages of the frame according to the present invention as well as other advantages of the embodiment described and shown will appear to the surgeon readers.
• the present invention is in no way limited to the embodiment chosen and shown, but encompasses all variants within the reach of those skilled in the art.
• the plates can have any length, shape and / or bending capable of allowing their implantation at any level of the spine.
• shape of the various elements can be adapted to allow the same type of intervention on animal spines.
• this frame can be used for osteosynthesis of other bones, or for blocking joints such as the hip, knee or elbow. It can also be used on artificial bones for educational purposes, in particular for demonstrating the surgical method.
• the plates which have been illustrated in the figures include passage openings 24 for the pedicle screws 25.
• these plates may not include holes for the passage of pedicle screws illustrated in the drawings, but will nevertheless remain in accordance with the present invention if they have a stud with a convex mounting surface.
• the mounting surface 30 is a concave surface of toroidal type, while the mounting surface 41 of the studs is convex, of spherical type.
• the present invention is in no way limited to this embodiment. Only the fact that the concave and convex mounting surfaces can cooperate with each other to obtain the desired adjustment latitudes.

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• Health & Medical Sciences (AREA)
• Orthopedic Medicine & Surgery (AREA)
• Life Sciences & Earth Sciences (AREA)
• Neurology (AREA)
• Surgery (AREA)
• Heart & Thoracic Surgery (AREA)
• Engineering & Computer Science (AREA)
• Biomedical Technology (AREA)
• Nuclear Medicine, Radiotherapy & Molecular Imaging (AREA)
• Medical Informatics (AREA)
• Molecular Biology (AREA)
• Animal Behavior & Ethology (AREA)
• General Health & Medical Sciences (AREA)
• Public Health (AREA)
• Veterinary Medicine (AREA)
• Surgical Instruments (AREA)
• Prostheses (AREA)

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• 1991
  • 1991-02-01 FR FR9101407A patent/FR2672203B1/fr not_active Expired - Fee Related
• 1992
  • 1992-01-31 EP EP19920905224 patent/EP0569497A1/de not_active Withdrawn
  • 1992-01-31 WO PCT/FR1992/000085 patent/WO1992013496A1/fr not_active Application Discontinuation

Non-Patent Citations (1)

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