FR3098101A1 - Assembly comprising an anchor intended to be placed on a bone, and at least one instrument allowing the establishment of this anchor on this bone - Google Patents

Abstract

The assembly concerned comprises a bone anchor (1) and at least one instrument (2, 3) allowing the placement of this anchor (1) on a bone; the anchor (1) is at a suture link and includes an anchor body (5). According to the invention, - Said screw (6) is integral with a rod (7) for mounting and operating in rotation, and is connected to this rod (7) by a breakable portion; - the instrument is in two parts (2, 3), a first part (2) of which is engaged in the second part (3) with the capacity to rotate with respect to this second part; said first part (2) has a distal cavity adapted to receive said rod (7) with a rotational connection; said second part (3) and the anchor (1) have means for rotating connection to the anchor (1) and an impaction surface suitable for bearing against the anchor (1). Figure for the abstract: Fig. 1

Description

Assembly comprising an anchor intended to be placed on a bone, and at least one instrument enabling this anchor to be placed on this bone

The present invention relates to an assembly comprising an anchor intended to be placed on a bone, and at least one instrument enabling this anchor to be placed on this bone. This assembly is particularly intended for use in reinserting the rotator cuff ligaments onto a humerus.

It is well known to reinsert a ligament or a tendon on a bone by means of an anchor implanted in this bone, the anchor being connected to one or more suture threads; once the anchor is in place, this or these threads are intended to cross the ligament or tendon to be reinserted and to be tied in such a way as to maintain this ligament or tendon in place on the bone while healing takes place ensuring the natural connection of the ligament or tendon to the bone.

A known anchor, of this type, has a threaded cavity opening out on its proximal side and a screw intended to be screwed into this cavity to make the connection of the suture thread to the anchor. Such an anchor has the advantage of being able to be combined not only with suture threads but also with flat suture braids, which gives the anchor wider possibilities of use.

In a certain number of existing assemblies, the instruments for installing the anchor are single-use, and therefore have the disadvantage of involving a substantial consumption of material; these instruments are therefore not very ecological and involve a significant cost of use.

Existing instruments also have the disadvantage of not always being very simple and quick to use.

Furthermore, a screw anchor of the aforementioned type has the disadvantage of not excluding the risk of excessive tightening of the screw in the anchor, which could lead to damage to the suture link; such damage to the link induces a risk of this link breaking when the link is put under tension.

In addition, some anchors induce a notable risk of the reinserted tendon or ligament becoming slack relative to the insertion site of the anchor, which slack is detrimental to the proper healing of the reinsertion of the tendon or ligament.

The present invention aims to remedy these various drawbacks.

The assembly concerned comprises, in a manner known per se, an anchor intended to be connected to at least one suture tie, and at least one instrument allowing the positioning of this anchor on a bone; the anchor includes an anchor body having a threaded internal cavity and a screw intended to be screwed into this cavity so as to ensure the connection of said at least one suture link to the anchor body.

According to the invention,

- Said screw is integral with a rod for mounting and operating in rotation, and is connected to this rod by a breakable portion;

- The instrument is in two parts, including a first part engaged in the second part with the ability to rotate relative to this second part; said first instrument part has a distal cavity capable of receiving said rod of the anchor with rotational connection; said second part of the instrument and the anchor have means for connecting in rotation to the anchor and an impaction surface capable of bearing against the anchor.

In practice, the anchor is mounted on the instrument by engagement of said rod in said distal cavity of the first part of the instrument, then this anchor is brought into a state of rotational connection with said second part of the instrument, and in bearing against said impaction surface; the instrument is then used to impact the anchor in a hole made in the bone to receive this anchor; the first instrument part is then actuated in rotation in the second instrument part so as to screw the screw into the anchor body, until the breakable portion breaks; the instrument, with the operating rod connected to it, is then withdrawn from the implantation site.

As is understandable, the invention provides an assembly allowing easy mounting of the anchor on the instrument, and easy screwing of the screw into the anchor, without tool interchange, and with exercise of a torque of maximum tightening of this screw in this anchor which is determined by the breakage of the breakable portion. This results in a simple and rapid use of this assembly, and an elimination of the risk of damaging the suture link by the exercise of an excessive tightening torque on the screw.

The invention also consists in taking the opposite view of the prior art consisting in providing several single-use instruments, used successively; on the contrary, it provides for a single, reusable instrument, the structure of which nevertheless remains relatively simple.

Preferably, the screw, the breakable portion and the rod for mounting and operating in rotation are formed by one and the same piece, said breakable portion having a reduced cross-section compared to that of the screw and the rod.

This assembly can thus be obtained simply and relatively inexpensively, in particular in a synthetic material such as PEEK (polyetheretherketone).

The connection in rotation of said first part of the instrument with said rod could be achieved by providing non-circular shapes in cross section of this rod and of the cavity intended to receive this rod. In the case of a rod of circular cross-section, said distal cavity has a circular cross-section but with a diameter such that said first part of the instrument is able to be inserted by force on said rod in order to create the aforementioned rotational connection. . In this case, according to a particular embodiment, the distal end portion of said first instrument part may have a tubular shape and two diametrically opposite slots, these slots making it possible to give this distal end portion a slight capacity of radial outward deformation which facilitates said engagement by force. Still in this same case of force insertion, said first part of instrument and said second part of instrument comprise means for longitudinal immobilization of said first part of instrument with respect to said second part of instrument. These longitudinal immobilization means making it possible to immobilize the first part longitudinally with respect to the second part when carrying out the aforementioned force insertion operation. These longitudinal immobilization means may in particular be in the form of at least one bayonet system acting between said parts of the instrument, that is to say comprising a pin secured to one of the two parts of the instrument, coming into engagement in a circumferential groove portion arranged in the other part of the instrument.

The aforesaid means for connecting said second part of the instrument with the anchor in rotation can in particular be constituted by a pair of projections diametrically opposed to each other, arranged at the distal end of this second part of the instrument. , and by a pair of corresponding cavities provided on the anchor body, capable of receiving said projections in an adjusted manner.

According to another aspect of the invention, the anchor has a proximal collar through which is arranged at least one passage hole for at least one suture link connected to the anchor.

This proximal collar is intended to bear against the bone during the impaction of the anchor in this bone, and thus makes it possible to define a determined depth of insertion of the anchor in the bone; simultaneously, said passage hole allows each suture thread, when this thread is under tension, to bear against the flange and not against the bone wall. These provisions make it possible to eliminate the risk of the suture link acting as a shear thread on the bone wall. It appears in fact that such a shearing effect is an important cause of risk of wear of the wire, and that it is also a cause of distension of this wire, following the insertion of this wire in the bone wall. , such distension being the cause of the aforesaid play taking of a tendon or ligament with respect to the anchor.

According to a preferred embodiment of the anchor, in such a case of an anchor body having a collar,

- The flange has two holes for passing at least one suture thread, arranged diametrically opposite to each other;

- the anchor body has a transverse channel for passage of said at least one suture link and two respective grooves extending between the respective outlets of this transverse channel and the respective holes for passage of said at least one suture link through the collar.

These grooves make it possible to house the strands of the suture thread(s) and to reduce the risk that these strands are crushed between the body of the anchor and the bone wall at the moment of the impaction of the anchor and that they are thus damaged. In this way, the risk of damage, and therefore of breakage, of the suture thread(s) is reduced.

Advantageously, the assembly according to the invention further comprises a tool holder including a part forming a fitted reception housing for the anchor and a base integral with this part, this base forming a support surface substantially perpendicular to the axis of said housing.

The tool holder is thus intended to be placed on a support surface with its bearing face placed against this surface, and the housing is intended to receive the anchor with the screw pre-positioned in the threaded cavity formed by the body. anchor; the tool holder thus makes it possible to position the anchor ideally for the coming of said rod of the anchor into engagement with said first part of the instrument, particularly when this engagement must be carried out by force.

Brief description of figures

The invention will be well understood, and other characteristics and advantages thereof will appear, with reference to the appended diagrammatic drawing, which drawing represents, by way of non-limiting example, a preferred embodiment of the assembly concerned; in this drawing,

is a side view of this assembly, comprising an anchor 1 intended to be placed on a bone, a first part of the instrument 2, a second part of the instrument 3 and a tool holder 4; in this figure 1, the anchor 1 is seen in longitudinal section, while the instrument parts 2, 3 and the tool holder 4 are seen externally;

is a view of the anchor 1 in perspective and on an enlarged scale, before assembly of a sub-assembly formed by a screw 6 and by a rod 7 for assembly and operation in an internal threaded cavity formed by an anchor body 5;

is a view of the anchor 1 similar to FIG. 2, with section of the anchor body 5 on a sector of 90°; a suture thread 50 has been placed on the anchor 1 and the screw 6 has been screwed into said cavity until axial blocking and breakage of the screw 6 with respect to the rod 7;

is a view of the first part of the instrument 2 from the side, with a rotation over a quarter turn with respect to the view according to FIG. 1;

is a side view of the second instrument part 3, in longitudinal section passing through the line VV of FIG. 1, namely along an axis of revolution of this second instrument part;

is a view of the second part of the instrument 3 in section along the line VI-VI of FIG. 5;

is a view of the second part of the instrument 3 in section along the line VII-VII of FIG. 5;

is a view of the second part of the instrument 3 in section along the line VIII-VIII of FIG. 5;

is a view of the proximal part of the second instrument part 3, showing a knurl that this proximal part comprises;

is a view in longitudinal section of the anchor 1 placed in the tool holder 4 and of the parts 2 and 3 of the instrument engaged one in the other, just before the operation of mounting the anchor 1 on the instrument formed by these instrument parts 2, 3;

is a perspective view, on an enlarged scale, of the distal portions of the instrument parts 2 and 3 as well as of a proximal portion of the tool holder 4 having the anchor 1 placed on it, just before these portions come into engagement distal with anchor 1;

is a perspective view, on an enlarged scale, of these same distal portions with the anchor 1 mounted on them, after removal of the anchor from the tool holder 4; And

is a view in longitudinal section, similar to figure 10, of the anchor 1 placed on a bone 100, before the reinsertion of a ligament on this bone by means of the anchor 1 and the suture thread 50.

detailed description

The anchor 1 represented in FIGS. 1 and 10 is intended to be connected to one or more suture threads 50 and to be implanted in a bone 100, visible in FIG. 13; in practice the wires (or a flat braid) are engaged through the ligament/tendon then loaded into anchor 1 and anchor 1 set in place. Once the anchor 1 is in place, this or these threads 50 are stretched and knotted so as to maintain this ligament or tendon in place on the bone 100 while healing takes place ensuring the natural connection of the ligament or tendon to the bone.

With particular reference to Figures 2 and 3, it appears that the anchor body 5 has:

- a pointed distal end, facilitating its insertion into the hole made in bone 100,

- circular anchoring projections 10 promoting its anchoring and its retention in this hole,

- a proximal collar 11,

- a transverse hole 12 for engagement of the suture thread(s) 50 through the anchor body 5,

- two longitudinal grooves 13 each located respectively opposite a respective outlet of this hole 12 and extending between this outlet and the flange 11,

- two holes 14 arranged through the collar 11 opposite these grooves 13, for the passage of the strands of the wire 50 through the collar 11, and

- Two holes 15 for connection in rotation to the second part of the instrument 3, also arranged through the collar 11, being arranged in a diametrical direction of this collar perpendicular to the diametrical direction in which the holes 14 are arranged.

Referring more particularly to Figure 3, it appears that the threaded axial cavity 16 formed internally the anchor body 5 communicates with the transverse hole 12, so that, when the screw 6 and screwed into this cavity 16, this screw is capable of tightening the suture threads 50 between it and the body 5.

The screw 6 is connected to the rod 7 by a breakable portion 20 of smaller diameter, sized so as to break when the screw 6 reaches the end of screwing inside the anchor body 5 and a torque of tightening is exerted manually on this rod 7 by means of the instrument parts 2 and 3 as described below.

The body 5 and the screw 6 - rod 7 assembly can in particular be made of PEEK (polyetheretherketone).

As understood with reference to Figures 1 and 4, the instrument part 2 is formed by assembling a smooth tubular rod 21 to a machined proximal part 22.

The rod 21 has an internal diameter such that the distal end portion 21a is able to be inserted by force on the rod 7; at this portion 21a, the rod 21 has two longitudinal slots 23, which open into its distal end and which are arranged diametrically opposite one another. Thanks to these slots 23, the two rod portions 21 delimited by these slots have a slight capacity for radial deformation making possible said insertion by force.

The piece 22 forms, on its proximal side, a flat 24 and, below this flat, a groove 25 comprising an axial portion and a circumferential portion which communicates with the axial portion; this groove 25 constitutes, with a stud 37 described later, a "bayonet" type system, allowing the longitudinal immobilization of the instrument part 2 with respect to the instrument part 3.

It appears in Figure 1 that part 22 has a mark 26 making it possible to identify the angular position of the part of the instrument 2 during its engagement in the part of the instrument 3.

The instrument part 3 is formed by the assembly of a distal tubular rod 30, a proximal part 31 forming a manual grip handle, and a proximal knob 32. These assemblies are made by means of pins 34 particularly visible in Figures 6 to 8; the wheel 32 has a distal groove in which the two corresponding pins 34 are engaged so that the wheel 32 is assembled axially to the part 31 while being able to rotate relative to the latter.

It appears in Figure 5 that the rod 30, the part 31 and the wheel 32 together form a longitudinal conduit 35 extending from one end to the other of the instrument part 3. As visible in Figure 10, the instrument part 2 is intended to be engaged in an adjusted manner in this duct 35; this engagement, however, takes place with the ability to rotate the instrument part 2 in the instrument part 3.

Referring to Figures 1, 5, 11 and 12, it appears that the distal end portion of the rod 30 has two diametrically opposite slots, giving this end portion a slight radial flexibility, like the portion end 21a, and that the rod portions 30a delimited by these slots have diametrically opposite longitudinal projections 36, adapted to come into fitted engagement in the holes 15 provided through the flange 11 of the anchor body 5. These portions 30a also have diametrically opposed notches, arranged in a diametrical direction perpendicular to the diametrical direction in which the projections 36 are arranged; these notches are therefore located opposite the holes 14 when the anchor 1 is mounted on the end of the rod 30, as shown particularly in Figures 11 and 12, and allow the portions 30a not to obstruct the passage of the threads of suture 50 on the proximal side of the flange 11.

Part 31 includes the aforementioned pin 37 capable of cooperating with the groove 25 of the instrument part 2, as can be seen in Figure 10.

The wheel 32 has a flat 38 which is capable of cooperating with the flat 24 of the instrument part 2 so as to create a connection in rotation between the instrument part 2 and it when this part 2 is engaged in the instrument part 3.

Referring to Figure 10, it appears that, in the position shown in which the stud 37 is at the entrance to the circumferential groove portion of the groove 25, the respective flats 24 and 38 of the part 2 and of the wheel 32 are in coincidence, so that wheel 32 can be used to pivot part 2 so as to engage stud 37 in said circumferential groove portion.

It also appears in this figure 10 that, in this same position, the distal end portion 21a of part 2 protrudes beyond the distal end of part 3, such that the portions 30a of the rod 30 do not impede the slight outward deformation of the portions of the rod 21 delimited by the aforementioned slots 23, so that the insertion by force of the rod 7 between these portions can be achieved.

Referring again to Figure 1, it appears that the tool holder 4 includes an axial part 41 forming a housing 42 for fitted reception of the anchor 1 and a base 43 integral with this axial part. The base 43 forms a lower bearing surface 44 substantially perpendicular to the axis of the housing 42.

In practice, the tool holder 4 is placed on a support surface with its face 44 against this surface, and the anchor 1, with the screw 6 pre-positioned in the cavity 16, is inserted into the housing 42; the tool holder 4 thus makes it possible to position the anchor 1 ideally for the arrival of the rod 7 in forced engagement in the cavity formed by the rod 21.

At the same time, part 2 is engaged in conduit 35 while being positioned angularly, by marking by means of mark 26, so that respective flats 24 and 38 come into coincidence with each other. This engagement is done by gravity, until part 2 meets the pin 37; the wheel 32 is actuated in pivoting so as to orient the part 2 for the engagement of this pin in the axial portion of the groove 25 then in the circumferential portion of this groove. This engagement in this circumferential portion achieves an axial immobilization of the part 2 in the part 3, so that the instrument formed by the parts 2 and 3 constitutes a unitary assembly that can be used to carry out the force insertion of the portion of distal end 21a on the rod 7. Once this insertion has been completed, the knob 32 is again actuated so as to disengage the stud 37 from said circumferential portion of the groove 25 and allow the sliding of the part 2 to be released again by relative to part 3. The latter can then be lowered so as to forcefully engage the portions 30a on the portion 21a then to engage the projections 36 in the holes 15 formed in the flange 11, until the end comes distal of the portions 30a in contact with this collar, as shown in Figure 12.

The instrument 2, 3 can then be used to impact the anchor 1 in the hole 100, then, by action on the wheel 32, to screw the screw 6 until the rupture of the breakable portion 20.

The disengagement of the instrument part 2 from the instrument part 3 makes it possible to extract the rod 7 from the cavity formed by the rod 21, and in this way, after sterilization, to be able to reuse the instrument formed by these parts 2, 3.

As appears from the above, the invention provides an assembly including an anchor 1 and an instrument 2, 3 which have the following decisive advantages:

- The instrument 2, 3 is reusable so that in addition to the ecological aspect, it involves a cost of use lower than homologous instruments in accordance with the prior art;

- the instrument 2, 3 is also relatively simple and quick to use;

- the anchor 1 excludes the risk of excessive tightening of the screw 6 and thus eliminates the risk of causing damage to the suture thread(s) 50;

- the flange 11 and the passage of the suture thread(s) 50 through this flange makes it possible to protect the suture thread(s) against friction against the bone wall, which makes it possible to avoid damaging this or these threads or cause a shearing effect of the bone wall by these threads, a source of a risk of distension of the thread or threads, detrimental to the rapid healing of the reinsertion of the tendon of the ligament on the bone.

Claims (10)

Assembly comprising an anchor (1) intended to be placed on a bone, and at least one instrument (2, 3) enabling this anchor (1) to be placed on this bone; the anchor (1) is intended to be connected to at least one suture link and includes an anchor body (5) having a threaded internal cavity (16) and a screw (6) intended to be screwed into this cavity so as to ensure the connection of said at least one suture link to the anchor body (5);
characterized in that
- said screw (6) is secured to a rod (7) for mounting and maneuvering in rotation, and is connected to this rod (7) by a breakable portion (20);
- the instrument is in two parts (2, 3), including a first instrument part (2) engaged in the second instrument part (3) with the ability to rotate relative to this second part; said first instrument part (2) has a distal cavity capable of receiving said rod (7) of the anchor (1) with rotational connection; said second part of the instrument (3) and the anchor (1) have means (15, 36) for rotational connection to the anchor (1) and an impaction surface capable of bearing against the anchor (1). Assembly according to Claim 1, characterized in that the screw, the breakable portion (20) and the rod (7) for mounting and operating in rotation are formed by one and the same piece, the said breakable portion (20) having a section transverse reduced compared to that of the screw (6) and the rod (7). An assembly according to claim 1 or claim 2, characterized in that said stem (7) has a circular cross-section and in that said distal cavity has a circular cross-section having a diameter such that said first instrument part (2) is adapted to be inserted by force on said rod (7). Assembly according to Claim 3, characterized in that the distal end portion (21a) of the said first instrument part (2) has a tubular shape and two diametrically opposed slots (23), these slots making it possible to give this portion distal end (21a) a capacity for deformation radially outwards allowing said engagement by force. Assembly according to Claim 3 or Claim 4, characterized in that the said first part of the instrument (2) and the said second part of the instrument (3) comprise means (25, 37) for the longitudinal immobilization of the said first part of instrument (2) relative to said second instrument part (3). Assembly according to Claim 5, characterized in that the said longitudinal immobilization means are in the form of at least one bayonet system (25, 37) acting between the said instrument parts (2, 3), i.e. that is to say comprising a stud (37) integral with one of the two instrument parts (3), coming into engagement in a circumferential groove portion arranged in the other instrument part (2). Assembly according to one of Claims 1 to 6, characterized in that the means of connection in rotation of the said second part of the instrument (3) with the anchor (1) are constituted by a pair of projections (36) diametrically opposed to each other, arranged at the distal end of this second instrument part (3), and by a pair of corresponding cavities (15) arranged on the anchor body (5), capable of receiving said projections (36) in a fitted fashion. Assembly according to one of Claims 1 to 6, characterized in that the anchor (1) has a proximal collar (11) through which is arranged at least one hole (14) for the passage of at least one suture connected to the anchor (1). Assembly according to Claim 8, characterized in that:
- the collar (11) has two holes (14) for passage of at least one suture thread, arranged diametrically opposite to each other;
- the anchor body (5) has a transverse conduit (12) for passage of said at least one suture link and two respective grooves (13) extending between the respective outlets of this transverse conduit (12) and the holes (14 ) respective passage of said at least one suture through the collar (11). Assembly according to one of Claims 1 to 9, characterized in that it further comprises a tool holder (4) including a part (41) forming a housing (42) for fitted reception of the anchor (1) and a base (43) secured to this part (41), this base (43) forming a bearing surface (44) substantially perpendicular to the axis of said housing (42).