FR2736257A1 - Surgical live tissue anchor - has pointed tip and retainer with shape memory effect formed with two vanes - Google Patents

Abstract

The anchor for penetrating a bone, consists of a pointed tip (2) and a retainer (3) made from a material with a shape memory effect a transformation temperature below that of the live tissue. The retainer has a central section which fixes to the pointed tip, and at least two vanes (11) connected at one end to the central section and having a free end at the other which points outwards and rearwards in relation to the direction of penetration to a distance greater than the diameter of the pointed tip.

Description

ANCHORING PART FOR LIVING FABRIC
AND ITS PACKAGING AND POSITIONING APPARATUS
Field of the invention
The present invention relates generally to an anchor for living tissue. In particular but not exclusively, the invention may relate to an anchoring piece for a bone element intended to be introduced into the interior of the bone element by penetration caused by a pushing force, without the need to previously drill into the bone element a penetration hole. The invention also relates to an apparatus for packaging and placing such an anchor.

Description of the Prior Art
There are already such anchors which are generally in the form of a pointed arrow or a pointed cone. Such a known anchor piece is driven into the bone using a specially designed tool which essentially consists of a thin rigid rod having a front end at the level of which the anchor piece is disposed while its tip is directed. forward. This rod has a rear end on which a practitioner can exert a relatively strong impact using a hammer or equivalent. By operating in this way, the practitioner can push the anchoring piece into the bone by making it penetrate directly into the bone, that is to say without having previously had to prepare a penetration hole in the bone. The anchoring piece of such a known type may have a flared rear part which is supposed to hold the anchoring piece in the bone without it being able to come out of it through the hole which it has formed directly in the bone when entering. In addition, it is also known to produce such an anchoring piece in which a rear part has flared parts which have a certain elasticity and which are intended to approach each other during the phase of driving into the bone. and which are then intended to reopen, that is to say to move away from each other in order to prevent extraction of the anchoring piece after it has reached a bone cavity.

 However, such known anchoring parts have not been satisfactory to date. The reason is as follows.

When such an anchor is pushed directly into a bone, the compression forces of the bone on the lateral parts of the anchor are very strong, and it follows from this that the elastic parts which are supposed to be able re-open elastically after being inserted into the bone are in fact definitively deformed in the direction of approximation to each other, which means that these parts are not effective in constituting a retention element definitively preventing the springing out of the anchor. Indeed, such an anchor must have very small dimensions, for example a diameter between two and four millimeters when the anchor enters the bone. For such very small dimensions, the elastic parts do not do not have sufficient lengths to be able to deform elastically with sufficient clearance.

 In addition, if we want the anchor parts to be more effective, these anchor parts become more voluminous and require too large forces or penetration shocks to be able to be driven into the bone.

 In practice, it has not been possible to produce somewhat effectively, anchoring parts of this type having a diameter of less than three millimeters.

 An object of the present invention is to provide a new anchoring piece for bone element intended to be introduced into the bone element by penetration caused by a pushing force, without the need to previously provide a hole in the bone element. penetration, this anchor having effective retention elements.

 Another object of the invention consists in proposing such an anchoring piece which can also be produced according to smaller diameter dimensions.

 Another object of the invention consists in proposing such an anchoring piece which can be introduced into the bone with a lower penetration pushing force.

 Another object of the invention consists in proposing a mounting device making it possible to use such an anchoring piece according to the invention in a more practical and efficient manner.

Summary of the invention
The invention therefore relates to an anchor for living tissue.

 According to an essential characteristic of the invention, this anchoring part comprises: a penetration part comprising a pointed front part; and a retaining part made of a shape memory material whose transformation temperature is lower than the temperature of living tissue, the retaining part comprising a central part adapted to be fixed on the penetrating part and at least two fins, each comprises an end connected to the central part and a free end which is directed towards the outside and towards the rear with respect to a direction of penetration of the anchoring part, the free end being located, in the absence of any deformation cold imposed, at a distance from a longitudinal axis of the anchoring piece greater than the largest radius of the penetrating piece.

 According to one embodiment of the invention, this anchoring piece further comprises a tail portion directed rearward relative to said direction of penetration and comprising a passage hole for the attachment to it of a surgical thread. .

 According to another embodiment of the invention, there is also provided a packaging and positioning device, intended for the packaging and placement of such an anchoring piece according to the invention, this device comprising a penetration tool comprising an elongated rod with a diameter less than the maximum of the anchor, the elongate rod comprising a front part detachably removable on the rear of the anchor and two diametrically longitudinal grooves opposite, and a ring threaded with minimum clearance on the elongated rod, so that two opposite strands of said surgical thread can be slidably housed respectively in the two grooves while being retained in the grooves by the ring.

 According to another embodiment of the invention, in such an apparatus, said ring can slide freely until it simultaneously surrounds a free end of said fins and a front end part of said elongated rod, the internal diameter of the ring being equal to or greater than a diameter corresponding to an external perimeter of the free ends of the fins when these fins are plastically deformed when cold while being brought close to one another, from which it follows that this ring serves to retain the fins in approximation positions before insertion of the anchor into living tissue, and when the elongated rod is making the anchor penetrate into living tissue, the ring remains in abutment on an external face of the living tissue and slides towards the back on the elongated rod as it sinks into living tissue.

 According to another embodiment of the invention, such an apparatus further comprises a reservoir which includes a housing intended to removably receive the anchoring part mounted on the front end of the elongated rod of the tool.

 According to another embodiment of the invention, in such an apparatus, said tank also includes a sealed internal cavity containing a body retaining cold.

 According to another embodiment of the invention, in such an apparatus, said reservoir further includes two branches directed towards the rear, the free end of each of which serves to be removably attachable to a corresponding end of said surgical thread to hold in place simultaneously and in one piece the reservoir, the anchor, the tool and the surgical thread.

Brief description of the drawings
These objects, characteristics and advantages, as well as others, of the present invention will be better understood during the detailed description of an exemplary embodiment which follows, illustrated by the appended figures among which
Figure 1 is an exploded longitudinal sectional view of an anchor piece according to the invention;
Figure 2 is a longitudinal sectional view of the same anchor piece but in a mounted position
Figure 3 is a longitudinal sectional view similar to that of Figure 2 but in which a penetration tool is associated with it, this tool also constituting another part of the present invention
Figure 4 is a longitudinal sectional view of the same anchor and the same penetration tool during a phase of penetration into the bone; and
Figure 5 is a side view of the entire packaging and positioning apparatus for the anchor, according to another aspect of the invention;
Figure 6 is a view similar to that of Figure 5 but in which the apparatus is in use for the establishment of the anchor in a bone; and
Figure 7 is a view similar to that of Figure 6 but in which the penetration tool is removed for a final operation of anchoring a ligament on the bone.

Detailed description of the invention
In the description, the terms "front", rear "," forwards "and" backwards "will be arbitrarily considered with respect to a direction of penetration of an anchor in a living tissue in which it must be inserted.

 In FIG. 1, an anchoring part 1 according to the present invention essentially consists of a penetration part 2 and a retaining part 3. The penetration part comprises a front part in the shape of a sharp point, for example in a pointed conical shape having a relatively small cone angle at the apex, for example between 15 and 45 ". The cone angle at an anterior to the apex may be greater than the cone angle at the apex , so that the sharp point has a profile along curved lines The penetration part 2 further comprises a shank part 5 situated at the rear of the penetration part 4 and which comprises a radial through hole (or chas ) allowing the passage of a surgical thread 6. The rear end of the penetration part 4 has a diameter greater than that of the tail part 5, which means that there is a radial shoulder 7 between the part of penetration 4 and the tail portion 5. The retaining part 3 comprises a base 9 provided with a central hole 10, and lateral tabs 1 1 which extend backwards and outwards from the base 9 The retaining piece 3 is made of a shape memory material.

 To mount the anchoring piece 1 according to the invention, it is necessary to thread the retaining piece 3 onto the penetrating piece 2 by threading the tail portion 5 into the hole 10, then threading the surgical thread 6 into the hole 7 of the tail part 5, as shown in FIG. 2.

 Then, to make this anchoring part penetrate any bone or any living tissue, it is advisable to mount the anchoring part 1 on the end of a special tool 15, as shown in FIG. 3. The special tool 15 essentially comprises an elongated rod 16 comprising a smaller diameter end 17 itself comprising a concentric central blind hole 18 opening forward at a rear end face 19. The tail part 5 is intended to slip into the hole 18 while the radial end face 19 comes to bear against a corresponding radial face of the base 9 of the retaining part 3 which itself comes to bear against the radial shoulder 8 of the penetrating part 2. A longitudinal slot 20 is provided diametrically in the front part 17 at the level of the hole 18 so that this slot 20 opens forward at the level of the radial face of end 19. So, the surgical thread 6 which passes through the hole 7 of the penetration part 2 can pass freely in the slot 20 of the tool 15. In addition, the rod 16 has a longitudinal groove 21 and another longitudinal groove 22 diametrically opposite. Thus, this same surgical thread can extend at the level of its two opposite strands, respectively in the groove 21 and in the groove 22 to reach a rear part of the tool 15. Finally, a split ring is provided. 23 which can slide longitudinally on the rod 16 and which has a minimum clearance between it and the rod 16 so that the wire 6 which is housed in the grooves 21 and 22 cannot escape from these grooves at the level of the ring 23.

 The anchoring piece according to the invention is put in place according to the following setting up method.

 First, the retaining part 3 is mounted on the penetration part 2. Then, the wire 6 is threaded on the tail part 5. Then, this assembly thus formed is mounted on the front end of the tool special 15 (as explained above). Then, as shown in FIG. 3, the assembly is cooled to a temperature below the transformation temperature (-15 "C to -200C) of the shape memory material of the retaining part 3, then the fins 1 1 of the part 3 are deformed by pressure in order to be brought closer to the tail part 5, then the ring 23 is slid on the rod 16 until it comes to surround the fins 11.

Next, the practitioner or surgeon pushes the assembly thus formed into living tissue, for example into human bone, by shock or pressure. During this insertion operation, the ring 23 remains external to the living tissue and it slides backwards on the rod 16. The retaining part 3 then heats up rapidly due to the temperature of the living tissue up to approximately 37 " C, that is to say a temperature higher than the transformation temperature. This heating causes, as is well known per se, a return of the part 3 in its form before the cold plastic deformation, that is to say that the retaining part 3 has its fins which move apart again.

Then, the practitioner removes the rod 16 The special tool 15 while simultaneously freeing the free ends of the wire 6 which are directed towards the rear. The wire 6 has its two strands which come out of the living tissue and which can be used as ties to fix an object or a living tissue against the external face 30 of the tissue 29 in which the anchoring piece has been inserted.

 If the living tissue 29 is a human bone, the anchoring piece is preferably pushed in until its fins 11 are located entirely in an internal cavity 31 of the bone 29 or in a tender or spongy part 31 of the 'bone 29. In this part 31, the fins can easily deviate in a relatively large spacing stroke, for example between 2 and 10 mm. In this case, the free rear ends 32 of the fins 11 come to bear against an internal wall 33 of the bone 29 or an interface 33 between the soft part 31 of the bone and the hard part 29 of the bone. In this condition, it is understood that the anchoring piece 1 according to the invention can no longer leave the bone 29.

 According to a variant, it is possible to introduce the anchoring piece 1 into a living tissue or a homogeneous bone, that is to say without the piece reaching any tender part or cavity 31. The force relatively large spacing of the fins 11, due to the use of shape memory material, will then be sufficiently effective to oppose any extraction of the anchor.

 As shown in FIG. 5, according to another variant, the anchoring part 1 can be used with a particular conditioning and positioning device 34, according to another aspect of the invention. The conditioning and positioning apparatus 34 is constituted by the tool 15 and by a sealed reservoir 35. The reservoir 35 contains a certain amount of water 36 (or any other body keeping the cold) in a cavity internal 37. The reservoir 35 comprises a housing or blind hole 38 and two arm parts 39, 40. The anchoring part 1 provided with its tool 15 is housed in the housing 38 while the tool 15 extends between the arms 39 and 40. The two free ends 41, 42 of the wire 6 can be hung under tension and removably at the free ends of arms 39 and 40, so that the assembly constituted by the reservoir 35, the part d anchor 1 housed in the housing 38, The tool 15 mounted on the part 1 and the wire 6 form a packaging and positioning device "ready for use" which is used to condition and store an anchor part 1 and to set up this part 1 by force penetration into the bone.

 Such "ready to use" devices can be stored in a refrigerator. Then, they can be removed from the refrigerator for a relatively long time, for example several minutes or an hour, to be placed on a waiting area for use by the surgeon, thanks to the fact that the frozen water 35 of the reservoir 34 keeps anchor piece 1 cold during this waiting period. The surgeon can then freely choose the precise instant when he wishes to use an anchoring piece by grasping an assembly, and by removing the reservoir 34 just at this instant.

 The tool 15 may further comprise a fixed sleeve 42 mounted on a shank portion 43 of the tool 15 and a sliding sleeve 44 threaded on the fixed sleeve 42. The fixed sleeve 42 comprises two longitudinal grooves 45, 46 diametrically opposite in which the two strands of surgical thread 6 pass. The clearance between the sliding sleeve 44 and the fixed sleeve 42 is less than the thickness of the wire 6 so that the wire 6 is trapped in the grooves 45, 46 while being able to slide freely along these grooves.

Figure 6 is a view similar to that of Figure 5 but in which the device 34 is in use for the establishment of the anchor piece 1 in a bone 29. This establishment is carried out giving a shock using a hammer 47 (not drawn to scale) on the rear end of the tail 43 of
The tool 15 (or by exerting a pushing force in any way).

 Figure 7 is a view similar to that of Figure 6 but in which the penetration tool 15 is removed for a final operation of forced application of a ligament 48 against the bone. 29 by tying the ligament 48 against the bone 29 using the two strands of surgical thread 6 which is kept permanently anchored in the bone.

 The invention is not limited to the embodiments which have just been described only by way of illustration.

Claims (7)

 1. Anchoring piece for living tissue characterized in that it comprises  a penetrating part (2) comprising a pointed front part (4); and  a retaining part (3) made of a shape memory material whose transformation temperature is lower than the temperature of living tissue, the retaining part comprising a central part (9) adapted to be fixed on the penetrating part ( 4) and at least two fins (11) each of which comprises an end connected to the central part (9) and a free end (32) which is directed outwards and backwards relative to a direction of penetration of the anchoring piece (1), the free end (32) being located, in the absence of any cold-imposed deformation, at a distance from a longitudinal axis of the anchoring piece (1) greater than the radius le larger of the penetration part (2).  2. Anchor according to claim 1, characterized in that it further comprises a tail portion (5) directed rearward relative to said direction of penetration and comprising a through hole (7) for the fixation on it of a surgical thread (6).  3. Packaging and positioning device (34), intended for packaging and placing an anchoring piece (1) according to any one of the preceding claims, characterized in that it comprises a penetration tool (15) comprising an elongated rod (16) with a diameter less than the maximum of the anchor (1), the elongated rod (16) comprising a front part (18) detachably removable on the rear of the anchor (1) and two diametrically opposite longitudinal grooves (21, 22), and a ring (23) threaded with minimum clearance on the elongated rod, so that two opposite strands of said surgical thread ( 6) can be slidably housed respectively in the two grooves (21, 22) while being retained in the grooves by means of the ring (23).  4. Apparatus according to claim 3, characterized in that said ring (23) can slide freely until it simultaneously surrounds a free end (32) of said fins (11) and a front end part (19) of said rod elongated (16), the internal diameter of the ring (23) being equal to or greater than a diameter corresponding to an external perimeter of the free ends (32) of the fins (11) when these fins are deformed plastically cold by being brought together others, from which it follows that this ring (23) is used to hold the fins (11) in positions of approximation before an insertion of the anchoring piece (1) into a living tissue (29), and when the rod elongated (16) is making the anchoring part (1) penetrate into the living tissue, the ring (23) remains in abutment on an external face (30) of the living tissue and slides backwards on the rod elongated (16) as it (16) sinks into the t living issue (29).  5. Apparatus according to claim 4, characterized in that it further comprises a reservoir (35) which includes a housing (38) intended to removably receive the anchoring part (1) mounted (18) on the front end (19) of the elongated rod (16) of the tool (15).  6. Apparatus according to claim 5, characterized in that said reservoir (35) further includes a sealed internal cavity (37) enclosing a body (36) retaining cold.  7. Apparatus according to one of claims 5 or 6, characterized in that said tank (35) further includes two branches (39, 40) directed towards the rear, the free end of each of which serves to be attachable from removably at a corresponding end (41, 42) of said surgical thread (6) in order to hold in place simultaneously and in one piece the reservoir (35), the anchoring piece (1), the tool (15) and the surgical thread (6).