FR2731610A1 - Anchor component for implantation in bone surface cavity - Google Patents

Abstract

A cylindrical body (15) is formed with a number of peripheral cut-out portions defining projecting fins (11). A cylindrical head (12) is attached or formed at the upper end of the body, with a diametral hole (120) which communicates with the exterior of the head by means of a lateral slot (121). The slot opens at the lower edge (130) of the head. The assembly is made of a material with shape-memory properties, and cooperates with other components, e.g. a shaft or pin which slides through the slot to engage in the diametral hole, which may then be heated to cause locking of the shaft within the head.

Description

 The present invention relates to an anchor intended to be inserted into a bone cavity, and the device for inserting said anchor into such a cavity.

 The human body has soft parts, in particular muscles, which are attached to the bone skeleton by means of a tissue, generally fibrous, forming for example the tendons or aponeuroses, while the bone parts are often separated from each other. by ligaments, capsuies or others.

 For traumatic or accidental reasons, or during a surgical procedure, these soft parts can be detached from their bony support and in order to attach them to the bone we use ie more often suture threads or steel threads which are fixed to the bone by means of screws, staples, anchors or other fixing means.

 The anchors known to date are screwed or inserted by impacting, in the manner of a throat, in a cavity previously formed in the bone, and are anchored in said cavity by means of fins which are folded against the anchor body. before its introduction into said cavity, and which then deploy in the manner of an umbrella, either by elasticity, or by traction on a cord which is fixed to them.

 However, due to the small dimensions of these parts, the known anchors are generally marketed with a suture thread which is fixed to them during manufacture, so that the surgeon no longer has the choice of the thread once the model of chosen anchor. It sometimes follows that the wire is not adapted to the stress to which it is subjected and breaks. on the other hand, each surgeon has his own habits in terms of wire, which he chooses in particular by anointing his material and its diameter.

 The object of the present invention is to remedy the various drawbacks of known devices by proposing on the one hand an anchor, preferably made of # a material with shape memory which leaves the surgeon the choice of suture thread, which I can fix to said anchor at the time of its insertion into the bone cavity, and on the other hand the device for inserting said anchor.

 We salute that a shape memory material is a material, most often based on titanium and nickel, and which possesses the property that is malleable at low temperatures, generally in the vicinity of 0 ^ C, and to recover its initial shape. . recorded in the molecular memory of the material, when the temperature rises, and in particular when it reaches approximately the temperature of the human body, soi = 37-C.

 An anchor according to @ invention is essentially characterized in that it comprises a body of generally cylindrical shape at the periphery of which fins are cut longitudinally joined by their lower end to said body, which is surmounted by a head of cylindrical shape in which is practiced diametrically a recess of substantially cylindrical shape proionged by an ass slot extends to the vicinity of the lower edge of said head.

 The slot in the head of the anchor according to the invention can advantageously be provided at the edge of a non-return tab preventing a thread inserted by said slot in the cylindrical recess to come out.

 The device according to 1 invention for inserting 1 anchor is, in a first embodiment, made up of two elongated parts, the first of which slides in the second at its open lower end, so as to allow it to pass out of said second part the end of said first sliding part to allow it to come, substantially perpendicularly, into contact with the upper surface of the head of the anchor in order to push it into a cavity formed in a bony body, 1 anchor being previously housed in a housing part which is secured by P one of its ends to the end of the first elongated part and in which a cut is made, complementary to that made in the head of the anchor, which comes opposite the latter when said anchor is positioned in said housing part.

By a cut in the housing part the user can pass a suture thread and ie lodge in the recess of the tette of 1 anchor, where it can be blocked by a non-return tab
In a second embodiment, the device for inserting 1 anchor consists of a support rod, one end of which is narrowed and secured to the upper face of this head of the anchor so that the attachment zone can rupture under i effect c torsion or bending of said support rod, once the anchor is placed in the bone cavity.

 The advantages and characteristics of the present invention will emerge more clearly from the description which follows and which relates to the appended drawing, it being understood that this description has no limiting character with respect to the invention.

In the attached drawing
- Figure 1 shows a perspective view of an anchor according to @ invention, the fins of which are deployed.

 - Figure la shows a plan view of an anchor according to the invention, the fins are folded.

 - ia Figure 1b shows a plan view of an anchor according to the invention whose fins are deployed.

 - Figure lc shows a plan view of the anchor head according to a second embodiment of 1 invention.

 - Figure c represents a plan view of the head of the same anchor und times the wire introduced into 1 recess and locked by the non-return tab.

 - Figure a shows a plan view of the two parts of the insertion device according to the invention.

 - Figure 2b shows a plan view and partial section of an operating part of the sliding element of the same insertion device.

 - Figure 3 shows an axial sectional view of the housing part of the same insertion device.

 - Figures 4a and 4b show a plan view and in partial section of the same insertion device during maneuver.

 - ia Figure 5 shows a plan view of a second embodiment of anchor insertion device according to the invention.

 If we refer to Figures @, la and 1b we can see that an anchor 1, made in a shape memory material, has a generally cylindrical body 15, in which are cut longitudinally four hooking fins 11, diametrically opposed two two, folded transversely, substantially in the middle, outwards, allowing the anchor 1 to be locked in a bone cavity when they are unfolded, as can be seen in Figures i 1b.

 The fins 1 are secured by their base 10 to the body 15 of the anchor 1, which is surmounted by a head 12 of cylindrical shape crossed diametrically by a recess 120 of semi-circular section, extended over all its length by an annuity 121 which extends to the lower edge 130, 1 recess i2û being intended to receive an artificial cord or ligament.

 It can also be seen in FIGS. 1a and 1b that the slot 121 of the head 12 comprises a flexible tongue 121, secured by one of its ends to the lower edge 130.

 If we now refer to Figures lc and ld we can see that ia tongue 121 allows a suture X to pass through in view of its introduction into the recess 120 by bending against the underside of the slot 121 but then prevents it / out of the head 12, as can be seen in Figure 1d.

 Referring now to FIG. 2a, it can be seen that an insertion device according to the invention comprises two parts 2 and 3 of tubular shape, the part 2 being able to slide in a bore 30 made axially in the part 3, which is provided at its upper end with a handle 3i.

 The sliding part 2 consists of a cylindrical rod 20 at the center of which is formed a transverse orifice 200 intended to receive the stud 210 of an operating part 21, shown in FIG. 2b, capable of sliding in a cutout 32 of bayonet type operated from the center of the part 3 towards the handle 3i.

 The cutout 32 allows the part 2 to slide, which comprises @ one of its ends 201 a cylindrical rod 22 intended to pass through one end 33 of the part 3 through an opening 34, the end 33 being of smaller diameter than the body 35 of part 3 and being externally threaded.

 The end face 220 of the rod 22 is intended to come into contact with the upper face 122 of the head 12 of the anchor 1 with a view to pushing it into a bone cavity.

If we refer to Figure 3 we can see that a part 4 for housing an anchor i has a generally cylindrical shape and that in one of its ends û is practiced axially a threaded thread 41 in which the end 33 of part 3 is intended to be screwed
The opposite end 42 of the housing part 4 has the same configuration as the head 12 of the anchor 1, which can be introduced into a bore 43 made axially in this end 2 and comprising two diametrically opposite semi-circular orifices 44, each extended by a cutout 440 which connects them and which extends towards the lower edge 45 of the part 4.

 When ia tette 12 2 of the anchor i is in abutment against the bottom 430 of @ bore 43, the orifices 44 as well as the cutout 440 come opposite, respectively from the recess 120 and from the slot 121, the cross sections of which are identical to those of said orifices 44 and of said cutout 440.

 The upper edge 45 ′ of a cutout 440 is rounded so as to facilitate the insertion of a suture thread 7 into said cutout as far as the orifices 44 and therefore into the orifice 120 of the head 12 of the anchor l when that -cl is housed there.

 It can also be noted that the bottom 430 of the bore 43 of the housing part 4 communicates axially by a bore 46, of a diameter substantially greater than that of the rod 22 of the part 2, with the bore 41 formed in i end 40 of part 4.

 Referring now to FIG. 4a, it can be seen that the housing part 4 is fixed by screwing to the end 33 of the part 3 while the sliding part 2 is placed in its high position by means of the part operation 21, the rod 22 of said part 2 being positioned, perpendicularly, against the upper face 122 of the head 12 of the anchor 1 which is housed in the cavity 43 of the housing part 4, the lower flat edge 47 of which is in contact with the edge 50 of a bone cavity 61.

 The anchor i, which has been previously cooled to a very low temperature, is partially inserted by its rounded lower part @ 4 in the cavity 61, its fins applied against the body 15, an cord or an artificial ligament 7 being ready to be inserted in the i20 recess.

 In FIG. 4b, it can be seen that anchor 1 is inserted into the bone cavity 61, ie cord 7, the two free ends of which 70 and 71 are located on either side of the housing part 4, being inserted in the recess 120 of head 12 of 1 anchor 1.

 5 total insertion of the anchor i into the bone cavity 51 is achieved by actuating the sliding downward, by means of the operating part 21, of the sliding part 2 whose tip 22 is in abutment against the upper face 122 of the head 12 of said anchor 1.

 The sliding rod 2 can advantageously comprise an electrical system of known type, supplied for example by a button cell and triggered by means of the operating part 21, intended to heat the rod 22, made of a material conducting heat ia, when the latter is in contact with 1 anchor 1. It is thus possible to quickly bring the anchor l, once fully inserted into the bone cavity 61, to a higher temperature, thereby unfolding the latching fins 11 which block the anchor 1 in the bone cavity 61.

 The fact of precisely heating the anchor 1 using the rod 22 allows this not to risk burning the surrounding tissues, as is frequently the case with the devices known to this gour.

 If we finally refer to Figure 5, we can see in this figure that in a second embodiment of the device c insertion of I anchor, the latter consists of a rod z narrowed to one of its extremities 51, which is secured to the upper face 122 of the head 12 of the anchor 1 by a self-breaking zone 52.

 The slot 121 of the head 1 anchor 1 is advantageously located in the extension of 1 narrowed end 51 of the rod 5 so as to make it easier to pass the suture.

 In this embodiment - anchor 1 is placed in the bone cavity using the rod 5 then the attachment zone 52 is broken by the surgeon by exerting either a bending or a torsion on the rod 5.

Claims (5)

1) Anchor (1) intended to be inserted into a bone cavity characterized in that it comprises a body (15) of generally cylindrical shape at the periphery of which fins (11) are cut longitudinally joined by their lower end (10) to said body (15), which is surmounted by a head (12) of cylindrical shape in which is formed diametrically a recess (120) of substantially cylindrical shape extended by a slot (121) which extends to the vicinity of the lower oro ( 130) of said head 12.  2 anchor according to claim i characterized in that it is made of a shape memory material. 3) device for inserting an anchor according to claim 1 or claim 2 in a bone cavity characterized in that it consists of two elongated parts (2,3), the first part (2) of which slides in the second part (3) open at its lower end (33) so as to let pass a cylindrical rod (22) integral with 1 end (20) of the sliding part (2) to allow it to come into contact substantially perpendicularly with the upper face ( 122) of the head (12) of the anchor (1) in order to push it into the bone cavity (61), the anchor (1) being previously housed in a housing part (4) secured by one of its ends (40) at 1 end (33) of the elongated part (3), the housing part (4) having a cutout (44, 440) complementary to the cutout (120,121) made in the head (121 with the anchor (1), which comes opposite the cutout (44, 440) of the housing part 4) when said anchor (1) is positioned in acite housing part (4). 4) device for inserting 1 anchor (1) according to the claim 3, characterized in that the sliding rod (2) comprises an electrical system intended to heat the point (22), made of a conductive material of the cnaieur, when that -cl is in contact with the head (12) of the anchor (l) 5) device for inserting an anchor according to claim 1 or claim 2 in a bone cavity, characterized in that it comprises a rod (5) secured to the upper face (122) of the head (12) of the anchor (1) by one of its narrowed ends (51) which forms a self-breaking attachment zone (52).