FR2794019A1 - Ostheosynthesis implant especially useful for long and small bones, comprises body including helicoidal coil of deformable material and means of supporting implant against the proximal and distal fragments of the bone - Google Patents

Abstract

The implant is new. The implant is provided with means of support against proximal and distal bone fragments, which are mutually aligned, and for later bringing close these fragments until finally they are in contact with each other. The implant comprises: i) a body in general revolution form, permitting its introduction into existing conduit or arrangement, abreast proximal bone fragment and into the distal fragment; ii) the means to support the implant against the proximal fragment of bone and/or fixing it in its fragment, further called proximal support means, to immobilize the implant axially in relation to this fragment; and iii) the means to support the implant against the distal bone fragment and/or fixing the implant in this fragment, further called distal support means, to immobilize the implant in relation to this fragment. The proximal and/or distal means are mobile in inactive position, in which they permit the introduction of implant, and in active position they are supported against the corresponding bone fragments, and/or fixing the implant to these fragments. The body comprises at least one part consisting of helicoidal coil of wire made of deformable material whose deformation properties allow for the variation of length of body from its axially elongated form permitting to fix it between the corresponding proximal and distal fragments of the bone, to its shortened form, allowing for ostheosynthesis. The means are also provided for introduction of implant into conduit while the means of support are in inactive position, as well as the means for changing the support means from their inactive position to the active position, before the body undergoes the variation of its length towards the axially shortened form, the latter means partially consisting of material with shape memory, able to undergo martensitic/austenitic transition to allow for ostheosynthesis, or elastic material. The distal support means are preferably built in such way as to anchor inside the distal fragment of bone and not at the cortical level of this fragment. The proximal support means consist of collar projecting around the body of the implant, formed by coiled flat wire spiral of wire with end joined to the wire forming helicoidal coil of implant body. The other end of collar forming wire, at the exterior level of flat spiral, is curved in the direction of distal end of implant, forming a spur anchoring the collar on the proximal bone fragment. The implant may also have longitudinal rigid part, radially stiffening the part of body consisting of helicoidal coil of wire of deformable material.

Description

The present invention relates to an osteosynthesis implant for the treatment of all types of bone, in particular long bones and small bones, this implant being designed to bear against a proximal bone fragment and a distal bone fragment whereas these fragments are mutually distant and then bring these fragments together until they come into contact with each other.

<B> It is common to osteosynthise long bones with intramedullary nails or, more specifically, the small bones of the hand, wrist, foot or ankle, using single or double threaded <B> or threaded or threaded spindles.

The reduction of a fracture and the maintenance of the fragments in mutual contact are, in general, relatively problematic <B> to </ B> achieve with intra-medullary nails, with or without locking.

The use of screws <B> to </ B> single thread involves, for the realization of the osteosynthesis, that the head of the screw comes to bear against the proximal fragment without the thread of the screw is in mesh with this fragment. <B> It is more necessary that this net comes sufficiently in contact with the distal fragment.

These constraints make it difficult to place such screws in certain cases, especially when the bone site is not very accessible. In addition, the search for a good anchorage in the distal fragment involves a support in the distal cortex, at the risk of piercing this cortex and thus to damage the surrounding tissues, nerves, vessels or cartilaginous surfaces.

The relative positioning of the fragments can be difficult to control, especially when using double-threaded screws. The use of screws also induces a risk of tearing and discharge of bone material at the fracture zone, this material then coming to oppose the bringing together and the perfect maintenance of the fragments in contact with each other. This problem arises particularly with fully threaded or conical screws.

In addition, on small bones, osteosynthesis screws induce significant risk of bursting of bone fragments during the introduction, given the constraints that their insertion exercises. The pins have the disadvantage of presenting risks of migration <B> to </ B> through the bone, which can lead <B> to a distal cortical piercing. . In addition, the establishment of a pin tends to cause the distal fragment to rotate, which causes problems for some bones, including the scaphoid. <B> It </ B> is then It is necessary to install several pins, according to different angulations, to immobilize this fragment in rotation, making the operation complex in certain cases.

The present invention aims to overcome all these disadvantages, by providing an osteosynthesis implant which has an easy implementation, which does not involve any risk. spacing of the bone fragments, or piercing of the distal cortex and ensuring perfect osteosynthesis.

The implant concerned comprises, in a manner known per se, a body of general shape of revolution, allowing its introduction into an existing duct, or arranged, through the proximal bone fragment and into the distal bone fragment. <B>; <B> </ B> <B> - </ B> means of support of the implant against the proximal fragment and / or fixation of this implant <B> to </ B> this fragment, hereinafter <B> </ B> proximal support <B>, </ B> own <B> to </ B> immobilize the implant axially relative <B> to </ B> this fragment , and <B> - </ B> means for bearing the implant against the distal fragment and / or fixation of this implant <B> to </ B> this fragment, hereinafter <B </ B> distal support <B>, </ B> own <B> to </ B> immobilize the implant axially relative <B> to </ B> this fragment.

According to the invention, <B> - </ B> the distal and / or proximal support means are movable between an inactive position, in which they are erased and allow the introduction of the implant into the conduit, and a active position, in which they bear against the corresponding bone fragment and / or fix this implant <B> to </ B> this fragment <B> - </ B> - said body comprises at least a part constituted by helical winding of a wire of deformable material, the deformation of this material allowing <B> to </ B> this body to vary in length between an axially elongated shape, allowing the positioning of said proximal support means and distal opposite the corresponding bone fragments, and an axially shortened shape, for performing the osteosynthesis <B> <B> - </ B> means are provided to allow the introduction of the implant in said while the said distal and / or proximal support means are in their inactive position, and <B> - </ B> means are provided to effect the passage of the distal and / or proximal support means from their inactive position <B> to their active position before the body begins <B> to </ B> vary to its axially shortened form or at the beginning of this variation.

The implant according to the invention can thus be introduced into the conduit by a single gesture, the distal and / or proximal support means then being placed in their inactive position and thus not impeding this introduction. These proximal and / or distal support means will become active before the body of the implant begins to shorten to achieve osteosynthesis or as soon as this shortening begins.

Said deformable material may be a shape memory material, such as a nickel-titanium alloy, brought to perform a martensitic / austenitic transition in order to perform the osteosynthesis. In this case, the implant is set up in this body <B> to </ B> the martensitic state and goes <B> to </ B> the shortened form that it presents <B> to </ B> > the austenitic state by evolution towards the temperature of the body in which the osteosynthesis is carried out.

This same deformable material may be an elastic material, such as stainless steel. In this case, the means provided for enabling the implant to be introduced into said conduit are shaped to allow the body of the implant to be stretched to the axially elongated shape thereof, in order to position the means for distal and / or proximal support with regard to the corresponding bone fragments. Osteosynthesis is performed by the elastic return of said material.

The means provided for effecting the passage of the distal support means and / or proximal their inactive position <B> to </ B> their active position may be constituted by parts in a material <B> to </ B> memory of form brought <B> to </ B> to make a martensitic / austenitic transition in order to perform the osteosynthesis.

Said passage thus occurs before the beginning of the shortening of the body.

These same means can also be constituted by parts made of an elastic material, which are shaped to deform during the introduction of the implant into the conduit so as to allow erasing, radially towards the implant interior, distal and / or proximal support means, and to regain their initial shape by elasticity as soon as the body of the implant begins <B> to </ B> evolve towards its axially shortened shape < B>; </ B> The distal and / or proximal support means are then shaped to bite into the wall of the bone fragment as soon as the body of the implant begins to <B> to </ B> evolve to its axially form. shortened.

Preferably, said distal support means are shaped to anchor in the distal bone fragment and not at the cortical level of this fragment, which avoids piercing said conduit to this cortical and thus to risk piercing this last.

According to a possible embodiment of the implant, said proximal support means are constituted by a flange projecting beyond the body of the implant, this collar being formed by spiral wound winding of a wire while the helically wound wire which forms said part of the body of the implant is connected to the end of this same wire.

The implant is thus relatively easy and fast to manufacture. The end of the wire which forms said flange located at the outside of said flat spiral may be bent towards the distal end of the implant to form a lug anchor said flange on the proximal bone fragment.

The implant may comprise a rigid longitudinal portion, which is adapted to radially stiffen said part of this body constituted by helical winding of a wire of deformable material. This rigid longitudinal portion may be a central rod secured to said proximal or distal support means, around which said helical coil extends, or may be a tubular sleeve secured to said proximal support means, <B> to </ B > inside which extends this same winding.

For a good understanding, the invention is <B> to </ B> again described below with reference to the attached schematic drawing representing <B> to </ B> title of non-limiting examples, several embodiments of the invention. implant it relates and an embodiment of a means provided to allow to introduce the implant in the bone conduit.

Figures <B> 1, 3, 5, 7 </ B> and <B> 9 </ B> are perspective views of various embodiments of the implant, prior to placement of the latter <B> Figures 2, 4, <B> 6, 8 </ B> and <B> 10 </ B> are respectively perspective views of these various embodiments of the implant, after implementation. Position of this implant and performing osteosynthesis <B>; <B> 11 to </ B> 14 are perspective views of various other embodiments of the <B> implant; <B> 15 </ B> is a view of the implant shown <B> in Figure 14, after placement of this <B>; </ B> Figures <B> 16 </ B> and <B> 17 </ B> are respectively sectional views of the implant shown in Figures <B> 1 </ B> 4 and <B> 15, </ B> and Figure <B> 18 </ B> is a view of a similar implant <B> to </ B> that shown in Figures <B> 3 </ B> and 4, with a stem allowing it to be put in place .

The parts or elements found on these different embodiments, or which are similar from one embodiment to another, are designated by the same reference numerals.

Figures <B> 1 to 10 </ B> and <B> 18 </ B> represent an osteosynthesis implant <B> 1 </ B> for the treatment of all types of bone, particularly long bones and small bones, this <B> 1 </ B> implant being intended to bear against a proximal bone fragment and a distal bone fragment while these fragments are mutually distant and then to bring these fragments together until they come in contact with each other.

In each case, this implant <B> 1 </ B> comprises a proximal collar 2 bearing against the proximal fragment, a body <B> 3, </ B> and bearing means against the distal bone fragment, hereinafter <B> </ B> distal support means <B>. </ B>

In the various embodiments shown in Figures <B> 1 to 10 </ B> and <B> 18, </ B> the flange 2 is formed by flat spiral winding of a wire 4. The end of this wire 4 located radially on the outside of the collar 2 is bent towards the distal end of the implant <B> 1 </ B> and is more or less sharp <B> to </ B> constitute an ergot <B> 5 </ B> that can penetrate into the cortex of the proximal bone fragment.

The body <B> 3 </ B> is constituted by a wire <B> 10 </ B> wound helically, connected by its proximal end to the wire 4. This wire <B> 10 </ B> constituting the body <B> 3 </ B> is made of shape memory material, especially nickel-titanium alloy. <B> It </ B> is shaped such that in the martensitic state of its constituent material, the body <B> 3 </ B> has an axially elongated shape, shown in FIGS. , 5, 7 </ B> and <B> 9, </ B> and that, <B> to </ B> the austenitic state of this material, the body <B> 3 </ B> has a shape 2, 4, <B> 6, 8 </ B> and <B> 10. Said axially elongate shape is such that, when the collar 2 bears against the proximal bone fragment , said distal support means are located opposite this distal fragment, while the axially shortened form is such that it allows to perform osteosynthesis.

The material of the yarn <B> 10 </ B> is brought <B> to </ B> to perform a martensitic / austenitic transition.

The distal support means differ from one embodiment of the implant to the other, but in each case these means are movable between an inactive position, shown in FIGS. , 3, 5, 7 </ B> and <B> 9, </ B> in which they are folded radially inwardly of the implant <B> 1 </ B> and therefore do not obstruct <B > to </ B> the introduction of this implant into the conduit for <B> to </ B> receive it, and an active form, shown in Figures 2, 4, <B> 6, 8 </ B> and <B> 10, </ B> in which they are expanded radially and are <B> to </ B> even to bear against or in the wall of the distal bone fragment.

In the embodiment shown in FIGS. 1 and 2, these distal support means consist of a claw 12 bent towards the collar 2.

In the case of Figures <B> 3 </ B> and 4, the implant <B> 1 </ B> comprises four of these claws <B> 1 </ B> 2, evenly distributed on its periphery.

The implant shown in Figures <B> 5 </ B> and <B> 6 </ B> comprises a tip <B> 13 </ B> of substantially conical shape, having a plurality of claws 14 arranged on its proximal side , which expand radially in their aforementioned active position, the assembly thereby constituting an anchor.

The implant shown in Figures <B> 7 </ B> and <B> 8 </ B> includes a transverse bar <B> 15, <B> sharp <B> at its ends, which is connected <B> to </ B> the distal end of the wire <B> 10 </ B> substantially by its middle part <B>; </ B> this bar <B> 15 </ B> is placed so oblique in relation to <B> to </ B> the longitudinal axis of the body <B> 3 </ B> in said inactive position, so that it is inscribed <B> to </ B> within the cross section of the body <B> 3, </ B> and can rotate to a position perpendicular <B> to </ B> the longitudinal axis of the body <B> 3 </ B> in said active position, such so that its sharp ends are located beyond the cross section of the body <B> 3 </ B> and can bear against the distal bone fragment.

The implant shown in Figures <B> 9 </ B> and <B> 10 </ B> comprises a cup-shaped standing part <B> 16 </ B> which, in its inactive position, has a portion device folded on the distal side. This folding causes the piece <B> 16 </ B> to have, in this position, a diameter equal to or slightly less than the diameter of the body. <B> 3. </ B> unfolds in said active position, so that the piece <B> 16 </ B> then has a diameter much greater <B> than </ B> that of the body <B> 3. </ B>

The various distal support means mentioned above are made of a shape memory material of the same nature as that constituting the body B, whose martensitic / austenitic transition corresponds to the transition. of these support means distal from their inactive position <B> to </ B> their aforementioned active position. However, this transition is <B> at </ B> a temperature different from that of the material constituting the wire <B> 10, </ B> such that said passage occurs before the beginning of the shortening of the body <B> 3. </ B>

The implants <B> 1 </ B> shown in Figures <B> 11 to 13 </ B> are identical <B> to </ B> that shown in Figures <B> 3 </ B> and 4 in that the body <B> 3 </ B> and the claws 12, but in the implant <B> 1 </ B> shown <B> to </ B> the figure <B> 11, </ B> the flange 2 is constituted by a disc provided on its periphery with sharp pins <B> 5; </ B> in the implant <B> 1 </ B> shown <B> to </ B> in FIG. 12, the flange 2 is replaced by a transverse bar 20 protruding beyond the perimeter of the body <B> 3, </ B> this bar 20 having two sharp lugs <B> 5 </ B> on its ends <B>; </ B> the <B> 1 </ B> implant shown <B> to </ B> Figure <B> 13 </ B> also includes a transverse bar 20, which is bent <B> to </ B> its ends to present two sharp pins <B> 5 </ B> as mentioned above.

In all the aforementioned embodiments, the implant <B> 1 </ B> comprises an orifice <B> 25 </ B> or an axial space <B> 26 </ B> allowing the passage of a rod, this rod being intended <B> to </ B> to bear against the implant <B> 1 </ B> to allow the introduction and the establishment of the latter.

In the example shown <B> to </ B> in Figure 18, <B> 30 </ B> traverses the <B> 26 </ B> space and has a distal fork <B> 31 </ B> shaped to bear against the base of a claw <B> 1 </ B> 2.

In practice, the implant <B> 1 </ B> and said rod <B> 30 </ B> engaged through it are introduced into the duct, or existing, through the proximal bone fragment and into the fragment distal bone. This introduction is carried out while the material constituting the wire <B> 10 </ B> and the distal support means are <B> at </ B> the martensitic state, and that therefore the implant <B> 1 </ B> has its axially elongate shape while said distal support means are radially retracted. Said introduction is continued until the collar 2 or strip 20 bears against the proximal bone fragment and until distal support means come in the distal bone fragment.

The heating of the material constituting the wire <B> 10 </ B> and said distal support means brings this material to its austenitic state, which consequently realizes the deployment of the distal support means and the shortening of the body <B > 3, </ B> to allow osteosynthesis.

The implant shown in Figures 14 <B> to 17 </ B> comprises a proximal collar 2 integral with a tubular sleeve <B> 35 </ B> within which extends, and can play, the wire <B> 10, </ B> and a similar <B> 13 </ B> distal tip <B> to <B> 5 </ B> and <B> 6. </ B>

The <B> f </ B> it <B> 10 </ B> is in this case an elastic material such as stainless steel, and the rod <B> 30 </ B> bears against the tip <B> 13 </ B> to allow not only the introduction of the implant <B> 1 </ B> in the conduit but especially to stretch the body <B> 3 </ B> beyond from the end of the sleeve <B> 35, </ B> until the tip <B> 13 </ B> is engaged in the distal bone fragment.

This sleeve <B> 35 </ B> can contain the body <B> 3 </ B> in the radial direction, to stiffen the implant <B> 1 </ B> during this introduction, and to lock the claws 14 in the extended position, the latter extending beyond the perimeter of this sleeve <B> 35 </ B> when in the active position, as it appears in FIGS. <B> 15 </ B> and <B> 17. </ B>

<B> It </ b> goes without saying that the invention is not limited to the embodiments described above <B> to </ B> as examples but that it embraces, on the contrary, all the variants. Thus, the implants shown in <B> f </ B> igures <B> 1 to 13 </ B> can consist of a <B> f </ b> 10 </ B> material elastic and be stretchable by means of a rod <B> 30 </ B> to bring the distal support means opposite the distal fragment <B>; </ B> the movable support means can be the means of proximal support instead of the distal support means, or both the proximal support means and the distal support means can be movable <B>; </ B> the distal support means can be made of elastic material < B>; </ B> in this case, these means unfold as soon as the shortening of the body <B> 3 </ B> occurs, the claws 12 or 14 then biting into the distal bone fragment.

Claims (1)

<B> CLAIMS </ B> <B> 1 - </ B> Osteosynthesis implant <B> (1), </ B> intended for the treatment of all types of bone, in particular long bones and small bones bone, this implant <B> (1) </ B> being intended to bear against a proximal bone fragment and a distal bone fragment while these fragments are mutually distant and then bring these fragments together until they come in contact with each other <B>; </ B> the implant <B> (1) </ B> includes <B>: </ B> - </ B> a body < B> (3) </ B> of general shape of revolution, allowing its introduction into an existing conduit, or arranged, through the proximal bone fragment and into the distal bone fragment <B>; </ B> <B> - </ B> means (2, 20) of bearing of the implant <B> (1) </ B> against the proximal fragment and / or fixation of this implant <B> to </ B> this fragment, hereinafter <B> </ B> proximal support means <B>, </ B> own <B> to </ B> immobilize the implant <B> (1) </ B> axially with respect to <B> to </ B> this fragment , and <B> - </ B> means (12 <B> to 16) </ B> of taking hold of the implant <B> (1) </ B> against the distal fragment and / or fixation of this implant <B> to </ B> this fragment, hereinafter <B> </ B> distal support means, clean <B> to </ B> immobilize the implant <B> ( 1) </ B> axially relative to <B> to </ B> this implant fragment <B> (1) </ B> characterized <B> - </ B> in that the distal support means and / or proximal <B> (1 </ B> 2 <B> to 16) </ B> are movable between an inactive position, in which they are erased and allow the introduction of the implant <B> (1) < / B> in the duct, and an active position, in which they bear against the corresponding bone fragment and / or fix this implant <B> (1) to </ B> this fragment <B>; </ B> </ In that said body <B> (3) </ B> comprises at least one part constituted by helical winding of a wire <B> (10) </ B> of deformable material, the deformation of this material allowing <B> to </ B> this body <B> (3) </ B> to vary in length between a <B> f </ B> axially elongated elm, allowing the positioning of said proximal (2, 20) and distal <B> (1 </ B> 2 <B> to 16) </ B> support means next to the corresponding bone fragments, and a shape axially shortened, to achieve <B>; </ B> <B> - </ B> osteosynthesis in that means <B> (30) </ B> are provided to allow insertion of the implant <B> (1) </ B> in said conduit while said distal and / or proximal bearing means <B> (1 </ B> 2 <B> to 16) </ B> are in their inactive position , and <B> - </ B> in that means are provided for effecting the passage of the distal and / or proximal support means (12 <B> to 16) </ B> from their inactive position <B> at their active position before the body <B> (3) </ B> begins <B> to </ B> vary towards its axially shortened form or at the beginning of this variation. Implant according to claim 1, characterized in that said deformable material is a shape memory material, such as a Nickel alloy. -Titanium, brought <B> to </ B> operate a martensitic / austenitic transition in order to perform osteosynthesis. <B> 3 - </ B> Implant according to claim <B> 1, </ B> characterized in that said deformable material is an elastic material, such as stainless steel, and that the means <B> (30) </ B> provided to allow insertion of the implant <B> (1) </ B> into said conduit are shaped to allow the body <B> (3) </ B> to be stretched implant to the axially elongate shape thereof, to position the distal and / or proximal support means <B> (1 </ B> 2 <B> to 16) </ B> next to the fragments corresponding bones. 4 <B> - </ B> Implant according to one of claims <B> 1 to 3, </ B> characterized in that the means provided to achieve the passage of the distal and / or proximal support means <B > (1 </ B> 2 <B> to 16) </ B> from their inactive position <B> to </ B> their active position consist of parts in a <B> to </ B> memory material of form, brought <B> to </ B> operate a martensitic / austenitic transition in order to achieve osteosynthesis. <B> 5 - </ B> Implant according to one of claims <B> 1 to 3, </ B> characterized in that the means provided to achieve the passage of the distal and / or proximal support means <B > (1 </ B> 2 <B> to 16) </ B> from their inactive position <B> to </ B> their active position consist of parts made of elastic material, which are shaped to deform when the introduction of the implant into the conduit in a manner <B> to </ B> allow erasing, radially inwardly of the implant, distal and / or proximal support means (12 <B> to 16), and to return to their original shape by elasticity as soon as the body of the implant begins to evolve towards its axially shortened shape, and in that the distal and / or proximal bearing means (12 <B> to 16) </ B> are shaped to bite into the wall of the bone fragment as soon as the body <B> (3) </ B> from the implant begins <B> to </ B> evolve to its axially shortened form. <B> 6 - </ B> Implant according to one of claims <B> 1 to 5, </ B> characterized in that said distal support means (12 <B> to 16) </ B> are shaped to anchor in the distal bone fragment and not at the cortical level of this fragment. <B> 7 - </ B> Implant according to one of claims <B> 1 to 6, </ B> characterized in that said proximal support means are constituted by a collar (2) projecting beyond of the Vimplant body (B) (3), this flange (2) being formed by flat spiral winding of a wire (4) while the helically wound wire (B) (10). which forms said part of the body <B> (3) </ B> of the implant is connected <B> to </ B> the end of this same wire (4). <B> 8 - </ B> Implant according to claim <B> 7, </ B> characterized in that the end of the wire (4) which forms said flange (2), located at the outside of said flat spiral is bent towards the distal end of the implant to form a lug <B> (5) </ B> for anchoring said flange (2) to the proximal bone fragment. <B> 9 - </ B> Implant according to one of claims <B> 1 to 8, </ B> characterized in that it comprises a rigid longitudinal portion <B> (35), </ B> own <B> to </ B> radially rigidify said portion of this body <B> (3) </ B> constituted by helical winding of a wire <B> (10) </ B> of deformable material.