WO2008037898A2

WO2008037898A2 - Apparatus for tibial-femoral resection

Info

Publication number: WO2008037898A2
Application number: PCT/FR2007/001588
Authority: WO
Inventors: Eric Duvillier; Jean-Marie Gineston; Gérard Simon
Original assignee: Eric Duvillier; Jean-Marie Gineston; Simon Gerard
Priority date: 2006-09-27
Filing date: 2007-09-27
Publication date: 2008-04-03
Also published as: FR2906125B1; FR2906125A1; WO2008037898A3

Abstract

The invention relates to a tibial-femoral resection apparatus for placing a prosthesis, that comprises insertion means (23, 23', 26) to be introduced under the femoral condyles of the knee and to rest on the upper portion (5) of the tibial plate (6), a block (8) with femoral and tibial cuts comprising two slots (20, 21) for receiving respectively a femoral cut blade and a tibial cut blade, and means (33) for attaching the block to the tibia. The insertion means (23, 23', 36) are follower means that co-operate with a rear portion (7) of the condyles when the knee is in a folded position, while means (9, 18, 19) are provided for blocking said follower means in position with the cut block (8) according to the orientation of the posterior bicondylian plane used as a reference and given by the follower means when the knee is in a folded position.

Description

TIBIO-FEMORAL RESECTION APPARATUS

The present invention relates to a tibio-femoral resection apparatus, i.e. resection of the tibia and knee, for the placement of a prosthesis, comprising sensing means of the posterior femoral condyles and a block of sections. femoral and tibial. It finds a particularly important application although not exclusive, in the field of knee surgery and more particularly in the case of partial arthroplasty.

By definition, partial or unicompartmental arthroplasty is only concerned with one part of the knee and must therefore adapt to the rest of the joint, which remains unchanged.

To achieve this goal, both in flexion and in extension, the surgeon must restore the plane and level of joint space of the part to be reconstructed compatible with those of the unaltered side, this plane and this level must in fact correspond to those prevailing before femoro-tibial wear. To arrive at this reconstruction, several preliminary operations are being carried out, quite complex and expensive.

First of all, it is necessary to establish a radiological assessment which is often difficult to interpret and susceptible to errors.

It is then necessary to perform a tracing of the axes on the various X-rays by simulating the correction envisaged therein. Lastly, the data provided by the radiological assessment during the operation must be implemented, with all the inaccuracies that this implies. Such constraints therefore entail disadvantages.

It is also known (WO 01/66 021) the use of a spacer to be inserted into the knee joint before the establishment of the block. But it does not allow to overcome the conventional means (radios etc.) to determine the position of reconstitution of the original joint space of the knee.

The present invention aims to overcome these disadvantages and is based in particular on two observations.

First, it has been noted that the femoral wear observed in uni-compartmental osteoarthritis concerns only the anterior part of the joint.

This implies that in flexion, because of the recoil of the femoro-tibial contact point, the posterior bicondylar line, after possible compensation of the posterior tibial wear that is rare, corresponds to the original joint space before knee wear. to operate.

As a result, when the knee is in the bent position it resumes a normal position that can be used as a reference. Then, and in view of this first observation, the invention starts from the idea of palpating the two posterior condyles in flexion, thanks to a minimally invasive approach, since it will be possible to by a single incision not exceeding 80 mm, then using this palpation where the condyles are therefore in a correct position, to precisely fix the cutting block. The tibial cut can then be performed at a determined distance, for example 9 mm from this posterior bicondylar plane, while simultaneously producing the posterior femoral cut without displacement. This produces a precise cut at the right height and in the right plane, and not deviated.

The present invention therefore aims to provide a device that responds better than those previously known to the requirements of the practice, in particular in that it allows a non-intrusive approach, with great accuracy in cutting, and an almost zero error rate, with simple ways to implement and inexpensive.

For this purpose the invention proposes in particular a tibio-femoral resection apparatus for the placement of a prosthesis, characterized in that it comprises feeler means of the posterior femoral condyles arranged to cooperate with the posterior portion of said condyles and for s pressing on the upper part of the tibial plateau and a block of femoral and tibial cuts having abutment means adapted to block said probe means in position with said cutting block according to the orientation of the posterior bicondylar plane given by the latter; two slots adapted respectively to receive a femoral cutting blade and a tibial cutting blade and means for fixing the block on the tibia. The invention also proposes a tibio-femoral resection apparatus for the placement of a prosthesis, comprising insertion means arranged to be introduced under the femoral condyles of the knee and to rest on the upper part of the tibial plateau. , a block of femoral and tibial cuts comprising two slots adapted to receive respectively a femoral cutting blade and a tibial cutting blade and means for fixing the block on the tibia, characterized in that the insertion means are sensing means arranged to cooperate with the posterior portion of said condyles when the knee is in the bent position, and in that it comprises means for blocking said feeler means in position with said cutting block according to the orientation of the posterior bi-condylar plane used as a reference and given by said feeler means when the knee is in the bent position.

The slots are advantageously and in turn arranged to allow cutting parallel to the bicondylar plane by said blades. Surprisingly, it will also be possible with the same cutting block as fixed and putting the leg in the extended position, and no longer flexed, to practice the distal femoral cut.

In an advantageous embodiment, the probe means comprise a first probe comprising on one side a substantially rectilinear handle provided with a cup-shaped end arranged to cooperate with the rear part of a first femoral condyle on the one hand and to rest on the upper part of the tibial plateau opposite another and on the other side a clean tail to come into abutment with a first portion of the block of cuts, and at least one second probe comprising on one side a handle having a bend provided with a cup-shaped end arranged to cooperate with the posterior part of a second femoral condyle on the one hand and to rest on the upper part the tibial plateau opposite and on the other side a clean tail to cooperate in abutment with a second portion of the cutting block.

In advantageous embodiments, one and / or the other of the following provisions is also used:

- The handle of the second or second feelers has a bend forming an angle between 90 ° and 120 ° with the corresponding tail; - The probe means comprise two second probes whose tails are rectilinear or substantially rectilinear, and whose handle portions having a bend are symmetrical or substantially symmetrical to each other with respect to the axis formed by their respective tail;

the blocking means comprise stop means of the block, said stop means comprising a third locking slot in abutment of the tail of one of the feeler means and a locking angle surface in abutment of the tail of the other middle feeler; the distal edge of the cup-shaped ends is refined to promote introduction between femur and tibia; the distal edge of the cup-shaped ends is sized to rise behind the condyle when the probe is in the blocking position on the block of cuts; - The cup-shaped ends are partially spherical or substantially spherical shape; the cup-shaped ends are substantially ovoidal; - The apparatus further comprises an alignment rod relative to the tibia and locking one of the probes in its locking position before fixing the cutting block.

The invention will be better understood on reading the following description of an embodiment given hereinafter by way of non-limiting example.

The invention refers to the accompanying drawings in which:

Figure 1 shows a damaged knee joint that can be operated and sectioned with the resection apparatus according to the invention.

Figure 2 shows an embodiment of a cutting block belonging to an apparatus according to the invention. Figures 3, 4 and 5 respectively show in perspective (Figures 3 and 4) and in view from above

(Figure 5) a first probe, here called internal probe and two second probes here called external probes according to the embodiment of the invention more particularly described here.

FIG. 6 is a perspective view of the resection apparatus, the elements of which are represented in Figures 2 to 5, in place, blocked on the bones of the flexed knee.

Figure 7 is a side view of the tibia and femur after positioning and fixing the apparatus of Figure S ₁ just before cutting.

Figure 8 is an enlarged view of the articulation with the apparatus shown in Figure 7.

Figure 1 shows a femoral condyle 1 with articular cartilage 2 damaged on a portion 3 (in broken lines in the figure), leaving the bone

4 naked which causes joint pain when it comes into contact with the upper part

5 of the tibial plateau 6.

When the knee is folded as shown in Figure 1, the posterior portion 7 of the undamaged condyle, comes in position opposite the rear portion of the surface 5 facing the tibia in its normal position since it has not not been eroded. As a result, the respective position of the femoral and tibial condyles can be used as a reference position.

Figure 2 shows the block 8 of sections of the apparatus according to the embodiment of the invention more particularly described here.

It comprises a locking slot, lateral horizontal 9, open on the side and intended to receive frictionally and to block the rectangular section of a first probe end stop. This slot is delimited at the top and side by an angled tab 10, projecting from the body 11 of the block, and at the bottom by an eccentric portion 12, itself partially hollowed out. 13. The tab 10 and the portion 12 are traversed from one side to the other by holes 14 and 15 centered around an axis 16, arranged to receive a rod 17 (in phantom in the figure) alignment relative to to the shin.

The body 11 of the block also comprises in the upper part, juxtaposed with respect to the slot 9, a surface 18 with a lateral abutment 19 formed by the lateral bent portion of the tab 10 which is therefore perpendicular to said surface 18.

This is for example located in the same plane as the top of the portion 12 and is intended to be pressed against the rectangular section of the tail of the second probe. When the tail of the first probe is inserted into the slot and the tail of the second probe is pressurized on the upper face and in contact with the stop 19 as will be described more specifically with reference to Figure 6, there occurs a blockage of the block with respect to the feelers.

The block 8 further comprises two other slots, namely a second slot 20 and a third slot 21 intended to allow the guided passage of sagittal saws (not shown) allowing the tibial cut (slot 20) and the posterior femoral cut (slot 21 ).

The block 8 is further provided in the lower part of two series of three holes 22 passing laterally and for securing the shin to the required level. It may also comprise a central portion 22 perforated to facilitate handling and minimize weight, and which is a function of the required distance between cutting blades. In an advantageous embodiment, this perforated portion may optionally be of smaller thickness and become a slot for receiving the tail of the internal probe. FIG. 3 shows an external probe 23 intended to be rotatable in place to palpate the posterior portion of the external condyle.

The probe 23 is intended to be introduced into the joint by the same path that will be used for the internal probe. But its shape is more complex since it has an elbow end portion 24 forming for example an angle β of 110 ° with respect to its rectilinear tail 25 of rectangular section, located in its extension and which is intended to cooperate with the slit 9 of the slice block mentioned above.

The portion 24 in the form of a bend, which forms a recess in "bayonet" can simultaneously bypass the patellar tendon, the massif of the tibial spines and the anterior cruciate ligament, the probing area here being that of the posterior condyle.

The end of the probe is in the form of a cup for example in the form of a spoon or hollow bean with a spherical inner surface, or simply spherical, and this in a manner similar to that which will be described with reference to line 4.

Figure 4 shows the internal probe 26 according to the embodiment of the invention more particularly described here.

It consists of a handle 26 provided with a rectilinear tail 27 of rectangular section, a spoon-shaped end 28 having a internal concave portion 29 and an outer convex portion 30, which allow to adapt to different sizes of knees operated. The spoon shapes are intended to palpate the posterior part of the femoral condyle on the one hand and to rest on the upper part of the tibial plateau on the other hand.

The edges 31 at the periphery of the spoon-shaped portions are advantageously progressively tapered outwards or refined (for example gradually reduced by half of its thickness over a few mm) to allow easier introduction between femur and tibia.

In addition and for example the length 1 of the zone corresponding to the edges 31, probing, was calculated to rise slightly behind the condyle and thus improve the strength of the internal probe and / or external.

Subsequently we will use the same references to designate the same elements or similar elements.

FIG. 5 shows the feeler means seen from above, namely the internal feeler 26 and two external feelers 23 and 23 ', the elbow portions 24 and 24' of which are symmetrical or substantially symmetrical with respect to the axis. 33 passing through their respective tail 25 as well as the ends 32 and 32 'shaped hollow cup arranged to cooperate with the corresponding condyles, left or right of the femur.

We will now describe with reference to FIG. 6 and FIGS. 7 and 8, the implementation of the device that will allow to make femoral and tibial resections according to the invention.

After incision of the knee of the patient, and if necessary and as and when, spacing of different tendons and ligaments appearing opposite, the internal probe 26 is put in place between the inner condyle 34 and the tibial plateau 35.

Then we put in place the external sensor 23 between external condyle 36 and tibial plateau 35 bypassing the patellar tendon, the tibial spine and the anterior cruciate ligament (not shown).

In case of difficulty of introduction of the external probe, the surgeon can introduce the probe in extension then return the knee in flexion to continue the intervention.

The two feelers 23 and 26 are then secured by inserting the tails 25 and 27 of the latter two on the one hand into the slit 9 of the slice block intended for this purpose and on the other hand into contact and pressure on the surfaces 18 and 19 of said block.

In other words, the shank 27 of the probe is manually held in abutment pressure on the surfaces 18 and 19 of the block, and the shank 25 is slid into the horizontal locking slot 9.

Surprisingly, this results in blockage of the feelers, because of the contradictory constraints and friction exerted both by the block on the tails and by the spoon ends of said feelers on the knee.

Block and tails of the feelers are in fact of metal or equivalent, cooperating with soft friction, which allows a sufficient blockage as soon as a pressure exists between them.

Now the knee by the existence of the ligaments in particular necessarily supports vertically and / or laterally on the probes, thereby generating constraints causing blockages.

Other means (not shown in the figures) can also be used to block or further improve the above blocking, for example comprising screws for fixing the tails on the block and / or a second slot, similar to the first, for vertical locking of the second tail combined or not with a screw and / or bolt with nut for example butterfly. Advantageously a bridge (not shown) can also be used as locking means. The bridge is then and for example secured to the block by means of an axis or a fixing screw and abuts above the upper part of the tail 2.7 so as to block against pressure with the surfaces 18 and / or 19 of the block.

With the invention, this is an excellent reference plane for cutting. There is no posterior condylar cartilaginous wear in unilateral osteoarthritis, and no or very little posterior tibial cartilaginous wear. In flexion, the posterior bi-condylar line is inscribed in the plane of the original joint space as it concerns non-worn contact zones of the knee to be operated.

Therefore, this line combined in another plane at the posterior tibial slope makes it possible to define the original line spacing and deduction the level of the section that will fill ideally and identically the loss of substance caused by the wear of the tibial cartilage. In fact, the posterior tibial slope is adjusted (see FIGS. 7 and 8) by aligning the extra-medullary rod 17 with the tibial crest 37 and finally the block 8 of sections is fixed by placing the pins 38 so that known in itself. Then the two probes 23 and 26 are removed and the tibial cut and the posterior femoral cut are performed with saw blades (not shown) inserted in the slots 20 and 21 spaced apart by the distance corresponding to the desired sectional planes 39 and 40. allowing the shading of the shaded areas 41 and 42 to be removed in FIG.

The type of prosthesis corresponding to the cutting block used is then put in place and fixed in a manner known per se. In an exemplary embodiment corresponding to a given prosthesis, overall size of 15 mm, the tibia cut is for example 9 mm below the condylar plane and that of the femoral condyle 6 mm above said plane. Thus, it is possible to define, with the aid of a specific instrumentation as claimed, cutting planes 39 and 40 and a level of cuts which make it possible, thanks to an intra-articular registration, to the opposite of the current actual locations. medular or intra-medular, to obtain excellent precision and an exceptional result, in a very little intrusive way. The present invention uses a finding to date not exploited by ancillary instrumentation, namely that there is no posterior condylar cartilage wear in unicompartmental osteoarthritis and that there is no or very little Posterior tibial cartilaginous wear in unicompartmental osteoarthritis.

In flexion, the posterior bi-condylar line is therefore inscribed in the plane of the original joint line of the knee to be operated because of non-worn contact areas.

This combined line in the other plane at the posterior tibial slope thus makes it possible to define the plane of the original line spacing and by deduction the level of the section which will make it possible to ideally fill (in the same way) the loss of substance. caused by wear of the tibial cartilage.

It is thus possible to define, using a specific instrumentation of the type claimed, a cutting plane and a cutting level.

In practice, the two probes are introduced separately and these two probes are secured to the block so as to define the adjustment plane of the posterior tibial slope. Once the plan of the original line is defined it is possible to use this information to achieve, at the right level, a cut whose plan will be strictly parallel to the plane of the original line spacing. After implantation of the prosthesis, the surface of the tibial component whose height has been initially defined by the operator is therefore found confused with the plan of the original interlining before wear of the patient.

The apparatus according to the invention thus makes it possible to define operationally a cutting plane and a level of cuts allowing to reconstruct a joint respecting the initial anatomy and this in a manner compatible with a minimally invasive pathway and this while being free of a complex radiological assessment and subject to many causes of errors. As is obvious and as also follows from the above, the present invention is not limited to the embodiments more particularly described. It encompasses all variants and especially those where a system of this type is used to achieve a total knee prosthesis.

Claims

1.Tibio-femoral resection apparatus for the placement of a prosthesis, comprising insertion means (23, 23 ', 26) arranged to be introduced under the femoral condyles of the knee and to rely on the part upper (5) of the tibial plateau (6), a block (8) of femoral and tibial cuts having two slots (20, 21) adapted to receive respectively a femoral cutting blade and a tibial cutting blade and means (33). fixing the block on the tibia, characterized in that the insertion means (23, 23 ', 26) are probe means arranged to cooperate with the posterior portion (7) of said condyles when the knee is in the bent position, and in that it comprises means (9, 18, 19) for blocking said probe means in position with said block (8) of cutting as a function of the orientation of the posterior bi-condylar plane used as a reference, and given by said means feelers when the knee is flexed. 2. Resection apparatus according to claim 1, characterized in that the probe means comprise: a first probe (26) comprising on one side a substantially straight handle provided with an end

(28) cup-shaped arranged to cooperate with the posterior portion of a first femoral condyle on the one hand and to rest on the upper part of the tibial plateau opposite and on the other side a tail (27) suitable for cooperating in abutment with a first part (9) of the block of cuts and at least one second probe (23, 23 ') comprising on one side a handle (32) having a bend (24, 24') provided with an end cup shape (32,

32 ') arranged to cooperate with the posterior portion of a second femoral condyle on the one hand and to rest on the upper part of the tibial plateau opposite and on the other side a tail (25). ) able to cooperate abutting with a second portion of the cutting block.

3. Apparatus according to claim 2, characterized in that the handle (24, 24 ') of the second or second feelers has a bend forming an angle between 90 ° and 120 ° with the tail (25) corresponding.

4. Apparatus according to any one of the preceding claims, characterized in that the probe means comprise two second probes

(23, 23 ') whose tails (25) are rectilinear or substantially rectilinear, and whose handle portions (24, 24') having a bend are symmetrical or substantially symmetrical to one another relative to the axis (33) formed by their respective tail.

5. Apparatus according to any one of the preceding claims, characterized in that the blocking means comprise stop means of the block, said stop means comprising a slot

(9) blocking in abutment of the shank (25, 27) of one of the probe means (23, 23 ', 26) and a surface (18) with a locking angle in abutment (19) of the tail of the other sensing means.

6. Apparatus according to any one of the preceding claims, characterized in that the distal edge (31) of the cup-shaped ends

(28, 32, 32 ') is refined to promote introduction between femur and tibia.

7. Apparatus according to any one of the preceding claims, characterized in that the distal edge (31) of the cup-shaped ends is sized to rise behind the condyle when the probe is in the locking position on the cutting block.

8. Apparatus according to any one of the preceding claims, characterized in that the cup-shaped ends are of partially spherical or substantially spherical shape.

9. Apparatus according to any one of claims 1 to 7, characterized in that the cup-shaped ends are substantially ovoidal.

10. Apparatus according to any one of the preceding claims, characterized in that it further comprises a rod (17) for alignment with respect to the tibia (37) and for locking one of the feelers in its locking position before fixing. cutting block.