EP2043555A1

EP2043555A1 - Bone anchoring device

Info

Publication number: EP2043555A1
Application number: EP07801411A
Authority: EP
Inventors: Michel Collette
Original assignee: Individual
Current assignee: Individual
Priority date: 2006-06-23
Filing date: 2007-06-25
Publication date: 2009-04-08
Also published as: US20090292321A1; WO2007147634A1

Abstract

The invention concerns an anchoring system for fixing a ligament graft in a bone tunnel. The invention concerns a hollow socket (1) to be anchored in the bone tunnel for passing through relay bands or suture. The socket has a cylindrical outer wall (6), a cylindrical or tapered inner wall (6') and two orifices (11, 12), the inner wall being capable of enclosing and locking the bands via the action of a locking member inserted in the socket. The outer wall (6) is provided with means to be secured to the bone tunnel (32), for example a screw thread fitted to the bone anchoring device.

Description

Bone anchoring device

The present invention relates to an anchoring system for fixing a ligament graft in a bone tunnel.

All pivotal sports such as rugby, football, skiing, etc., lead to a significant strain on the knee ligaments and therefore pose a significant risk of traumatic injury. This risk is greatly increased when these sports are practical at a high level.

The short, thick anterior cruciate ligament extends obliquely from the prespineal surface of the upper face of the tibia to the axial face of the outer condyle of the femur and provides anterior rotatory stability of the knee.

The accidental rupture of the anterior cruciate ligament is one of the most frequently encountered lesions in sports pathology of the knee, often resulting in partial or complete sports disability.

Nevertheless, there are surgical techniques of reconstruction of the anterior cruciate ligament that can restore the stability of the knee and, therefore, its functional abilities.

Reconstruction of anterior cruciate ligament can be achieved by means of a ligament graft introduced into bone tunnels, tibial and femoral, whose articular orifices coincide with the insertion zones of the natural anterior cruciate ligament.

SUBSTITUTE SHEET (RULE 26) The definitive anchoring of the graft is obtained by incorporation and gradual adhesion of the graft to the walls of the ossicular tunnel.

This incorporation occurs relatively rapidly (approximately six to eight weeks) if a graft taken from the patellar tendon is used, having at each of its extremities a small bone block coming from the patella and tibia. This graft of the bone-tendon-bone type thus comprises a central ligamentary part and two bony parts, the latter allowing a very good fixation in the bone tunnel This type of sampling has significant potential disadvantages namely a weakening of the extensor apparatus , residual pain, a risk of fracture of the patella or rupture of the patellar tendon weakened by the levy of which they were the object.

In order to avoid these drawbacks, ligament grafts taken from the tendons of the crow's foot, that is to say the union of the end tendons of the sartorius muscles, internal and semi-tendinous muscles, called the graft of. type DI-DT.

This is indeed a less invasive technique, the risk of adverse effects related to the levy is much lower.

However, the graft is then made of a pure tendinous tissue, that is to say without bone blocks at its ends. This in relation to bone graft transplantation, poses a technical problem of graft fixation in the bone tunnel.

It must be known, in fact, that it will take at least three months, and sometimes more, for the inserted tendon tissue to adhere well to the wall of the bone tunnel. During all this time, the strength of the assembly will therefore rest mainly on the quality of the artificial fixations that will be put in place during the intervention.

If the graft fixations are not effective enough, the repeated tensile stresses associated with the resumption of knee mobility will cause a gradual shift of the graft into the bone tunnel with loss of initial tension and recurrence of laxity.

Several modes of attachment of ligamentous grafts in a bone tunnel are known, each of them having, to varying degrees, serious limitations.

A usual method of attachment is to introduce a so-called interfering screw between the ligamentous graft and the wall of the bone tunnel into which the graft has been introduced beforehand.

Experimentally, it has been demonstrated that the mechanical resistance to tearing of the type of grafts DI-DT fixed by interference screw is of the order of 35 to 40 daN on average.

In extreme cases, the mechanical resistance to tearing may not exceed 20 daN.

In addition, the most recent experimental studies studying the behavior of these grafts when subjected to cyclic stress in order to simulate what will happen during rehabilitation show that this type of fixation does not effectively neutralize the gradual slide of the graft that occurs during each voltage spike.

This sliding causes a gradual loss of the initial tension and may even, after a few hundred cycles, cause the complete removal of the graft out of the bone tunnel.

Finally, the crushing of the tendinous tissue by the screw, all the more important that one desires a solid fixation, can be very harmful for the histological evolution of the tendinous tissue which is likely to be sheared, to become necrotic and, in the end, to be incorporated into the bone sometimes very mediocre.

Another device to avoid the disadvantages of the interference screws is to pass through the ligament loop a relay strip synthetic fabric itself fixed on a small metal bar (type endo-button). After having traversed the entire bone tunnel along its longitudinal axis by pulling the relay strip and the ligament loop behind it, this bar pivots and applies to the bone cortical bone, thus neutralizing the possible removal of the graft.

This type of assembly makes it possible to obtain a resistance which, according to the literature, does not however exceed 50 daN on average. However, it is clearly demonstrated that, subjected to cyclic tensile forces, the relay strip deforms and progressively lengthens permanently (especially as its initial length is large) which will also result in a gradual loss of initial tension applied to the graft when it is put in place.

However, it is accepted that the knee movements occurring during the course of everyday life and, consequently, during the free reeducation exercises, generate peaks of cyclic traction in the cruciate ligament or its substitute of up to 50 daN.

This means that allowing the patient to undertake intensive and early rehabilitation, which is an increasingly pressing demand from sports patients, after reconstruction of the anterior cruciate ligament, obviously involves risks of deterioration of mechanical properties. graft, namely recurrence of laxity or risk of accidental wrenching.

These risks of degradation of the fixation in a bone tunnel already very real when using a graft type os bone tendon, are even greater if one uses a transplant type DI-DT yet much more advantageous from the point from the disadvantages secondary to the sampling.

An object of the invention is therefore to propose a device for attaching a ligament graft in a tunnel bone which has a high tensile strength to limit the risk of tearing or sliding of the ligamentous graft in a bone tunnel.

The patent application WO 2004/045465 represents the closest prior art and relates to a technique for fixing a ligament graft suspended by textile strips screwed into bone tunnels by means of a special screw which has been called TLS screw (Tape Locking Screw).

The exceptional mechanical properties of this fastening system compared to other systems on the market have been demonstrated in the mechanical laboratory in a completely indisputable way. However, the experience gained in current surgery for more than three years after having performed more than 300 cases of surgical reconstruction using this fixation system shows that there are still some technical problems that may reduce the quality of the results in vivo compared to the results of experimental mechanical tests.

These technical problems are related on the one hand to the individual variations of the bone quality and on the other hand to the quality of placement of the TLS screw. Bone quality varies considerably from one individual to another depending on age, sex, mineralization rate, etc. As it has been confirmed experimentally, the resistance to tearing and especially to sliding of the ribbon depends the quality of the bone in which the screw is implanted. A soft bone will be much less resistant than a hard bone. On the other hand, the healing process of a traumatized bone firstly comprises a phase of bone resorption due to to the work of osteoclasts which necessarily precedes the reconstruction phase secondary to the work of osteoblasts. It is therefore not excluded that the strength of the initial assembly is significantly altered during the bone resorption phase which could for some time jeopardize the strength of the assembly and could slip the tape relative to decrease the tension in the graft and therefore, the stability of the knee restored during the operation. As the bone strength is not measurable on a case-by-case basis, such a potential weakening of the assembly would force the surgeon to return to the techniques of protection of the graft (splint, partial discharge) for all cases operated, while the goal The essential element of the TLS technique was, by proposing an extremely solid fastening system, to be able to free itself from the protection techniques without risking compromising the quality of the final mechanical result. The other possible factors of reduction of the efficiency of the system are related to the quality of the implantation of the screw.

The radiographic examinations (notably by CT) that have been carried out systematically in operated patients have shown that the screw does not always follow very closely the axis of the bone tunnel into which it is introduced. The divergence of the path of the screw relative to the axis of the bone tunnel in which the strips pass is a frequent risk and unfortunately uncontrollable by the surgeon if it is not radiographically what in practice is not feasible in the course of intervention. The postoperative controls make it possible to identify the problem but at this moment, it is obviously no longer possible to correct the situation. It is clear that a screw which is divergent with respect to the bone tunnel will be less effective in resisting the sliding of the ribbons than a screw perfectly following the axis of the bone tunnel. This factor unfortunately constitutes a potential pitfall inherent to the TLS technique, which is difficult to avoid and whose impact on the quality of the assembly varies on a case-by-case basis and is not measurable.

The third risk factor clearly identified is the insertion depth of the screw. As the screw is introduced by a small incision (about 1 cm) the surgeon works blind and must rely on the graduations of placement instruments to assess the depth of introduction of the screw especially to the femur or the thickness of the integuments is much more important than in the tibia. However, experience has shown that there is a significant risk of being wrong in the evaluation of the insertion depth of the screw. A screw that is too deep or too shallow will not give the same quality of fastening of the ribbons as if it is at its proper level. This hazard is also a factor in the reduction of mechanical quality, the importance of which is individual and unmeasurable. In addition, if a screw is introduced too shallow, it can cause irritation of the soft tissue where it is derived from the bone and cause at this place a chronic inflammatory reaction for the least embarrassing or painful.

Another disadvantage of the original TLS technique lies in the fact that it forces the surgeon to divide the bone tunnel into two distinct parts requiring a different size of digging: a large portion (femoral and tibial box), opening intra-articularly to receive the end of the graft ligamentary, digged retrograde from the inside to the outside and a thin portion, opening outwardly, dug from the outside inwards, allowing tapping from outside to inside to prepare the housing of the screw. Although the technical solutions to achieve this result have been made and described in the patent document WO2004 / 045465 (winged auger) it must be recognized that this embodiment is certainly more difficult and longer to achieve a bone tunnel. of a single caliber as in conventional ligamentoplasty techniques.

There is no technical impossibility to use the TLS system with bone tunnels of a single caliber, but in practice this leads to having to use extremely large screws since one should prepare their housing from a tunnel already dug the caliber of the graft. However, from one patient to another, this size can vary between 7 and 10 mm, whereas in the original TLS technique, the housing of the screw is prepared from a tunnel whose caliber is always 4, 5 mm in diameter.

Knowing that all these adverse factors can be combined to varying degrees in the same individual, there is still a need for improvement of the TLS technique as described in the aforementioned patent application.

The aim of the present invention is to propose a system making it possible in all cases to obtain an optimal quality of fixation of the TLS system, ie in all patients regardless of their bone quality while eliminating the risks of mispositioning. of the screw (divergence, excess or lack of depth). The present invention makes it possible not only to standardize the quality of the results but also thanks to a simplified technique allows the use of bone tunnels of a single caliber.

The present invention proposes to improve the effect of a screw or similar locking member by providing to associate therewith a hollow socket comprising an outer wall, an inner wall and two orifices, generally but not necessarily a wider and a narrower .

More specifically, the invention provides a hollow socket to be anchored in a bone tunnel for the passage of relay strips or suture characterized in that it has an outer wall, an inner wall and two orifices, said inner wall being adapted to to grip and block said strips by the effect of a locking member introduced into the socket.

Other aspects of the invention are mentioned in the dependent claims appended hereto.

The surgical technique is easily adapted to practice this new device and the invention therefore also relates to the associated method.

According to one embodiment, the inner wall of the sleeve corresponds to the negative impression of a tape locking screw. In other words, in the thickness of the inner wall of the socket, there is a spiral groove whose shape corresponds exactly to the thread of the locking screw. The depth of the groove is calculated so that after tightening the screw in its socket, the entire screw has penetrated into the socket after compacting the ribbons in the grooves of the sleeve according to a predetermined optimum torque in function of the mechanical properties of the material used.

According to an optional aspect of the invention, the outer wall of the sleeve is provided with at least four anti-rotation fins intended to neutralize in the bone the torsional torque induced by the tightening of the screw in its socket.

The widest orifice, directed outwards, corresponds to the penetration inlet orifice of the screw. Both in the femur and in the tibia, it is known that the bone tunnel to be provided forms with the cortical bone a variable angle on a case-by-case basis of 30 to 60 °. In order to facilitate the complete burying of the socket in its bone box, according to one embodiment, the inlet orifice of the screw is inclined by about 30 ° relative to the plane perpendicular to the major axis of the socket. According to another aspect of the invention, the union between this inlet and the outer wall (short side) of the sleeve is a flange intended to abut on the cortical bone thus preventing the penetration of the socket beyond this cortex. Although the conical shape of the socket is already a brake in itself to a possible excess of penetration, this overflow provides additional security and above all allows to place the socket reproducibly from one individual to another regardless of the angulation of the bone tunnel with respect to the cortex. According to another embodiment the sleeve is not conical but cylindrical on its entire outer surface. The inner cavity could be either conical or cylindrical depending on the locking mechanism of the ribbon that is selected.

The invention will be better understood on examining the appended drawings presented solely by way of non-limiting examples in which:

Fig. the watch schematically and in perspective a socket according to the invention.

Fig. Ib and Ic are corresponding horizontal and vertical sections.

Fig. Id shows the general shape of a socket.

The figure shows how socket 1 is positioned in a bone tunnel.

Fig. 2 shows the screw 9 in place in the doule'lle 1. The technique of use of this ligament fixation system is shown schematically from Figure 3 to Figure 7:

Fig. 3a illustrates the installation of the guide pins

Fig. 3b illustrates the realization of tunnels 32 from outside to inside. Fig. 4a illustrates the preparation of the housing 44 of the socket.

Fig. 4b describes the final appearance of tunnels 32 and bone boxes 44.

Fig. 5a illustrates the introduction of the sockets 1 by means of a sleeve holder also sliding on the guide pins 31.

Fig. 5 b illustrates the appearance of the tunnels after placement of femoral and tibia sockets. Fig. 6a shows the passage of the strips 21 in the tunnels 32 and insertion of the graft 61 into the knee by pulling on the strips 21.

Fig. 6b shows the appearance of the graft 61 after its introduction.

Fig. 7a illustrates the locking of the graft to the femur.

Fig. 7b shows the appearance of the graft after complete locking.

Figs. 8a and 8b respectively illustrate another embodiment of the invention consisting of a cylindrical sleeve to be screwed and a cylindrical sleeve to be driven or wedged in the bone tunnel.

Figs. 8c and 8d illustrate the same cylindrical bushings but optionally provided with a large head intended to bear on the cortical surface.

Fig. 9a illustrates in longitudinal section a cylindrical sleeve to be screwed.

Fig. 9b illustrates the same screw after the introduction of the ribbon locking member. Figs. 10a-10c illustrate the case where the ribbon is jammed by a locking member which is not a screw

Figs. lla-lli illustrate the steps of a method of surgical reconstruction of the anterior cruciate ligament.

detailed description

Fig. the watch schematically and in perspective a socket according to the invention having a first orifice 11 and a second orifice 12 narrower and an outer wall 6, and the stop edge 3. Fig. Ib and Ic are corresponding horizontal and vertical sections showing four anti-rotation fins 2, the inner wall 6 ', and the inner groove 4'. Fig. Id is a longitudinal section showing the flange 3 and the beveled section of the broad part of the cone, with an angle of about 30 ° between the longitudinal axis b of the sleeve and the plane a perpendicular to this axis.

The figure shows how the sleeve 1 is positioned in a bone tunnel made according to 3 different angulations relative to the cortical bone. In each case the sleeve stops on the cortex, where it forms an acute angle with the bone tunnel.

Fig. 2 shows the screw 9 in place in the sleeve 1 compacting the ribbon 21 of suspension of the graft in the groove 4 'of the wall 6' of the sleeve 1. The technique of use of this ligament fixation system is schematized from FIG. Figure 3 in Figure 7 for a surgical reconstruction of the anterior cruciate ligament at the knee joint.

Fig. 3a illustrates the establishment of the guide pins 31 for guiding the piercing instruments of the bone tunnels at the ends of the femur 7 and the tibia 8.

Fig. 3b illustrates the realization of tunnels 32 from outside to inside by means of hollow drills sliding on the guide pins 31. The tunnel is hollowed right through in a single gauge according to the measurement of the caliber of the ends of the graft.

Fig. 4 illustrates more particularly the preparation of the housing 44 of the sleeve 1 by means of a hollow metal instrument 41colluant also on the guide pins 31 and one end 42 comprises a conical member of shape and size strictly identical to the final bushing. Thus, this conical member is provided with cutting edges preparing the bone grooves which will receive the anti-rotation fins of the sleeve and it is also provided with a cortical stop rim 43 just like the final socket. Penetration is done with a hammer. By sinking, the instrument compact the walls of the cylindrical tunnel by creating a conical shaped box whose depth corresponds to the maximum degree of penetration of the instrument that is to say when its cortical stop edge abuts against the entrance to the bone tunnel

Fig. 4b describes the final appearance of tunnels 32 and bone boxes 44, the guide pins being always present.

Fig. 5a illustrates the introduction of the sockets 1 by means of a sleeve holder also sliding on the guide pins 31. The sockets are driven by hammer until they are blocked in their penetration by their conical shape and by the stop 3 of the cortical stop margin.

Fig. 5b illustrates the appearance of the tunnels after placement of the sockets 1 to the femur and tibia. Fig. βa shows the passage of the strips 21 in the tunnels and introduction of the graft 61 in the knee by pulling on the strips.

Fig. 6b shows the appearance of the graft 61 after its introduction. Fig. 7a illustrates the locking of the graft to the femur by the establishment of the locking screw 9, then, tensioning the graft 61 to the shin and locking by a similar screw 9 '.

Fig. 7b shows the appearance of the graft after complete locking. It will be understood that the fastening system as illustrated and described above can have considerable advantages:

1: The tightening torque of the screw 9 in its socket 1 is known by manufacture and therefore fully predictable unlike the TLS screw whose torque is random and depends mainly on the quality of the bone recipient, highly variable an individual to another. The use of a screw dynamometer would even be able to fine tune the tightening torque and make it identical in all operated regardless of the quality of their bones.

2: The risk of a possible excess depth of introduction as found in the original TLS system is eliminated because, thanks to its conical shape, the bush stops automatically when it reaches the bottom of its box and its ledge abuts on the cortex at the entrance of the tunnel. The risk of lack of depth of introduction also disappears since the sleeve is driven by hammer until it stops automatically for the reasons already exposed.

3: The risk of divergence between the screw and the axis of the tunnel (and therefore strips), as identified in the TLS system, no longer exists since the conical housings are made by means of an instrument sliding on the pins guides allowing to perfectly align the axis of the stalls with the axis of the bone tunnels. The bushing door slides on the same guide pin which imposes a perfectly controlled direction of the instrument during the introduction of the sleeve. Once the bushing in place the screw has no choice but to find the prefabricated groove of the inner wall of the sleeve automatically ensuring optimal clamping of the tape. 4: Not only does the present system solve all the residual mechanical problems of the original TLS system while maintaining the exceptional performance, but also thanks to a highly simplified technique since the bone tunnels are made in one piece according to the caliber of the graft, whereas the TLS system required the separate realization of blind boxes and fine tunnels intended for the creation of the housing of the screw. According to the preferred (but not restrictive) embodiment of the present system, the bushing and the screw are made of biocomposite material, that is to say combining a bioabsorbable polymer, for example of the PLA (PbIy Lac ^' tic AcTd) type, with an osteogenic substance. inducer, for example, of the TCP (Tri Calcium Phosphate) type. The foreign material thus introduced not only slowly resorbs with time but also does so by stimulating the local proliferation of bone tissue. After playing their mechanical role, the fasteners (socket and screw) slowly disappear to leave some room for the bone tissue of the recipient host. The suspension strips can also be made of absorbable material which after complete absorption of the system would leave a perfectly clean and natural environment. Since the biocomposite material is very hard, there are no more objections to reducing the size of the implants, depending on the situations encountered, since the tightening occurs between two elements of equals. hardness whereas the original TLS system somehow required the use of large diameter screws. It is indeed by crushing and compacting the bone around it that the TLS screw makes it possible to obtain a sufficient tightening effect of the ribbon.

Like the TLS screw, the present system makes it possible to block textile strips such as they are used in ligamentous surgery but it could also serve as a means of blocking simple suture threads which, having re-tensioned any ligamentous structure, could be very effectively blocked by clamping between a sleeve and a locking screw, thus eliminating the need to make stopping nodes sometimes very difficult to achieve.

Figs. 8 to 10 illustrate a particularly preferred embodiment of the invention. In this embodiment, the hollow sleeve is essentially a cylindrical member and no longer a conical member. In cylindrical mode, two types of introduction and anchoring of the hollow organ into the bone can be imagined: either a screw-in member as shown in FIG. 8a or an ankle-type hunting member (the same principle as FIG. socket of Figure 1) as shown in Figure 8b.

The screw member (FIG 8a) therefore comprises a cylindrical body 80 of 20 to 25 mm long for an outside diameter of the cylinder of about 10 mm. The outer wall has a wide, relatively sharp thread, resembling the thread of the lag bolts used in the wood, or the broad and deep thread of the spongy bone screws. This wide and cutting net 81 provides extremely strong bone anchorage. We can also predict base a small flange 82 intended to stop on the cortex. The oblique introduction of this screw relative to the bone surface would require a small milling of a few millimeters so as to increase the penetration of the screw into the bone and reduce its external dimensions. This small milling would pose in principle no particular technical problem. One could also if desired increase the bearing surface on the cortical bone by replacing the small collar by a real screw head 83 which should be convex and flat as shown in Figure 8c. It goes without saying that such a screw head would also require a small milling to partially bury it in the bone and reduce the external size.

Figure 8b shows a similar cylindrical member but adapted to be driven into the bone tunnel rather than vissé.- For this purpose, the outer surface- ^"the cylin ^'dre 10 mm could be provided with fine edges perpendicular to the major axis of the The hollow body is parallel to one another and the cortical support collar also requires a small milling operation to at least partially bury the head of the ankle.

The locking of the ribbons inside the socket can be achieved essentially in two ways:

1 - either by screwing_ using the same principle as the original TLS screw. Note however that in the present device, it is no longer necessary to give the locking screw a conical shape since it can come to stop at the entrance of the socket. Figure 9a shows a cylindrical sleeve 90 to be screwed in longitudinal section. FIG. 9b shows the same section after introduction of the locking member 91 of the ribbon 21.

This locking member is constituted by a screw 91 with a large pitch and foam thread (TLS principle) whose diameter is adjusted to come jamming the tape by clamping against the inner wall of the sleeve and in the internal aliasing. This locking screw could have a conical shape like the TLS screw but this device as has already been said is no longer really necessary and a screw of cylindrical section would achieve the same result, possibly more easily.

2 - either by blocking. In this case, the core of the bushing has been hollowed out in the form of a cone and the locking member having the same shape will simply be driven into the conical cavity in order to wedge the ribbon by wedge effect.

Fig. 10a shows such a sleeve in longitudinal section. FIG. 10b illustrates the fastening mechanism of the ribbon 21 after insertion of the locking member 22. FIG. 10c constitutes a variant of this device in which the inner wall 23 of the sleeve and the outer wall 24 of the 22 'blocking has been provided with fine indentations 25 so as to avoid the risk of accidental release of the system.

An additional advantage of the present system is that once the tibial tunnel is made entirely at the graft size, it can to penetrate the knee by the tunnel itself from outside to inside as is done in classical techniques (and no longer through the arthroscopic opening). This makes it possible to preserve the remains of the broken anterior cruciate ligament which, it seems, could significantly favor the revascularization of the graft and its incorporation into the bone tissue. It can indeed be considered that it is from these residual tissues that the vascularization of the graft begins, which is essential for its incorporation and survival.

The introduction of the graft by the arthroscopic orifice as described in the TLS technique of the patent document WO 2004/045465 requires on the contrary (and unfortunately) the excision of these tissues so as to avoid their intussusception in the tunnel. during the introduction of the graft, likely to block the penetration of the graft in his stall. One skilled in the art will understand that this could therefore prove to be a handicap or a hindrance to the incorporation and healing of the graft.

It will be appreciated by those skilled in the art that the use of cylindrical sockets allows the use of standard 10 mm gauge sockets which correspond to the maximum observable size for anterior cruciate ligament grafts. The drilling instrumentation of the tunnel would therefore comprise hollow two-segment drill bits, a first segment of variable caliber depending on the graft size (from 6 to 10 mm) and the second segment, of constant diameter, of 10 mm corresponding to the socket housing. Such a standardization would be more difficult in the case of a conical socket because the recess The taper of the stump must always be substantially greater than the diameter of the tunnel accommodating the graft.

The invention also relates to a technical nnuvpllp surgical reconstruction of the anterior cruciate ligament using for example a sleeve and a locking member to be screwed. The method according to the invention is summarized and schematized in the following manner with reference to FIGS. 11 a-i:

Preparation of the graft (Fig. 11a): a single tendon of the crow's feet is removed. The tendon is wound four to five times on itself to obtain a short closed loop with four or five strands. Two transfixing stitches are placed at both ends of the loop to neutralize the slipping of the strands together. A surgical textile strip is passed freely through each end of the loop, thereby allowing suspension and fixation of the ligament loop.

The loop thus made is placed on a traction table by means of the strips and a prestressing of 50 kg is applied to the system for 15 to 20 minutes before introducing it into the knee. This prestressing deforms the graft somewhat and thus neutralizes any phenomenon of parasitic elongation that may occur during the postoperative period, which would lead to relaxation in the graft and at least partial reappearance of joint laxity. The graft is calibrated to know the tunnel drilling diameter. Preparation of bone tunnels (Fig.llb-d): Placement of guide pins in the femur and tibia under arthroscopic control using conventional instruments (sights, etc.) (Fig. 11b) The end of each of the pins corresponds to the intra-articular anchoring zone chosen by the surgeon for docking the graft.

Drilling of the bone tunnels from outside to inside to the femur and then to the tibia according to the size of the graft (Fig. Ile). The instrumentation has a series of two-segment hollow wicks: the distal segment is variable (from 6 to 10 mm) and corresponds to the measured size of the graft. The proximal segment is constant and corresponds to the caliber of the socket (10mm). The use of this special wick thus allows to realize in a single passage the housing of the ligament and that of the socket. Digging is also done from outside to inside. Fig. Hd schematically shows the appearance of the tunnels after drilling.

Implantation and fixation of the graft (Fig. Lle-i): a pull wire is introduced into each of the tunnels from the outside to the inside of the knee and then recovered by the anterior arthroscopic anterior approach. This pulling wire makes it possible to draw the strips into the knee, then through each of the tunnels and collect them at the external orifice of each of the tunnels. This method allows to introduce the graft by the endoscopic approach by simply pulling on the strips as shown in Figure 6a and 6b. An alternative is to introduce a single pull wire into the femoral tunnel first from out into the inside and then retrieve this wire through the tibial tunnel from inside to out (Fig. This thread then makes it possible to attract the strips suspending the femoral pole of the graft through the tibial tunnel and then the knee and then through the femoral tunnel (Fig. llf). This method thus makes it possible to introduce the graft through the tibial tunnel πnmmp in most traditional ligamentoplasty methods. As mentioned above, it may be advantageous in that it avoids excessively generous debridement of the entrance to the tibial tunnel, which could have a negative effect on the subsequent revascularization of the graft.

Passing the strips into the femoral socket and screwing this socket into the bone housing prepared for this purpose. 11 g). Passage of the strips into the tibial socket and screwing of this socket into the bone housing prepared for this purpose. llg).

Stretching the femur graft by simply pulling on the strips. The penetration of the graft to the femur is maximum when it abuts on the end of the socket. Blocking the ribbons by inserting the locking screw into the femoral socket (Fig.llh). Tensioning of the graft to the tibia by simply pulling on the strips and blocking the strips by inserting the locking screw into the tibial socket (Fig. Hh).

Figure Hi shows the final appearance after locking the femur and tibia by the locking screw and section strips.

This description relates to an intervention where the sleeve method described in this report would have been used for both the femur and the tibia. All variants are obviously possible and we understand that we can use a hybrid system where the femoral pole of the graft would be fixed by an ordinary TLS screw or even an endo-button type system and where only the tibial pole would be fixed using the socket method to allow the introduction of the graft through the tibial tunnel.

Claims

Hollow socket (1) to be anchored in a bone tunnel intended for the passage of relay strips or suture, characterized in that it has an outer wall (6), an inner wall (6 ¹ ) and two orifices (11, 12), said inner wall being adapted to grip and block said strips by the effect of a locking member introduced into the socket.

2. Bushing according to claim 1 wherein the outer wall (6) is provided with a means for securing the bone tunnel (32).

3. Bushing according to claim 2 characterized in that the securing means is constituted by a screw thread adapted to the bone anchor.

4. Bushing according to claim 1, 2 or 3 characterized in that the outer wall is substantially cylindrical in shape and the inner wall is cylindrical or conical.

5. Lampholder according to claim 4 comprising at its upper orifice a head or a collar for stopping the sleeve on the cortical plane.

6. Bushing according to claim 1, 2 or 3 characterized in that it is substantially conical in shape and the inner wall is cylindrical or conical.

7. Bushing according to any one of the preceding claims, characterized in that the plane of the inlet orifice of the bushing is inclined by approximately 20 to 50 °, preferably approximately 30 °, relative to a plane perpendicular to the large axis of the socket.

8. Socket according to claim 7 wherein at the junction between said inlet port and said outer wall (short side) of the sleeve is a flange (3) intended to abut on the cortical bone thus preventing the penetration of the sleeve beyond this cortex.

9. Lampholder according to any one of the preceding claims made of biocomposite material.

10. Lampholder according to any one of the preceding claims, characterized in that it is manufactured in the same material as that of the anchor screw.

11. Bushing according to claim 2 characterized in that the outer wall of the sleeve is provided with at least two, preferably four anti-rotation fins (2).

12. Bushing according to any one of the preceding claims characterized in that it comprises a thread on the inner wall.

13. Bushing according to the preceding claim characterized in that the thread is provided complementary to that of the locking member taking into account the thickness of the strips to be blocked.

Fixing device set comprising an anchoring member and a socket according to any one of the preceding claims.

15. Set for fixing device according to the preceding claim wherein 1 'anchoring member is a screw, a tapered body smooth or toothed.

16. Set according to the preceding claim wherein the thread is blunted and has a wide pitch, preferably about 5 mm.

17. Set according to claim 14 or 15 wherein the distal end of the locking member is rounded and foam.

18. A method of surgical reconstruction using a graft with strips, characterized in that at least one sleeve and a suitable locking member, such as a screw, are inserted, said member being intended to block the strips in the socket, itself introduced into at least one previously pierced bone tunnel.

19. A method of surgical reconstruction of the anterior cruciate ligament characterized in that a sleeve and a locking member are used, for example a screw comprising the following steps

- preparation of a graft (Fig. 11a), for example from a crow's foot tendon, wound to obtain a closed loop with several strands

- placement of transfixing sutures at both ends of the loop

RECTIFIED SHEET (RULE 91) ISA / EP - Passage of a surgical textile strip through each end of the loop, thus allowing suspension and fixation of the ligament loop

- prestressing - calibration of the graft

- placement of guide pins in the femur and tibia under arthroscopic control to determine intra-articular anchorage areas (Fig. 11b)

- drilling of bone tunnels from outside to inside the femur and then to the shin with a hollow wick, each time in a single passage, the distal segment being variable and dependent on the graft size, the proximal segment being constant and corresponding to the caliber of the socket

- introduction of a pull wire in one or each of the tunnels from outside to inside to bring the strips into the knee and recover them at the external origin of each tunnel

- screwing or locking the bushings (Fig. llg)

- At the femur, tensioning the graft by pulling on the strips until the abutment of the graft on the end of the sleeve, then blocking by introduction of the body or locking screw

- At the tibia put tension of the graft by pulling on the strips until abutment of the graft on the end of the tibial socket and blocking by introduction of the body or locking screw.

20. A method of surgical reconstruction according to the preceding claim wherein a single pull wire is introduced into the femoral tunnel first from outside into and then retrieved through the tibial tunnel from inside to outside (Fig.

RECTIF _I ED _S HEET (RULE 91) ISA / EP allowing to draw the strips suspending the femoral pole of the graft through the tibial tunnel then the knee and then through the femoral tunnel (Fig. llf).