FR2752519A1 - Tibial and femoral cutter guides for total prosthetic knee surgery - Google Patents

Abstract

The guide assembly has demountable guide column (42) at the end of which a feeler is mounted, a connecting hole for an alignment and threading guide (50) and two side bores (412) which are angled for fixing on the upper end (31) of the tibia (30) by threaded rods. The femoral cutting guide has a cutting jig having a femoral feeler and a piercing guide at its centre. There is a centro-medullary rod and a piercing guide with a collar. A plate has a longitudinal groove against which the distal femoral cutting guide is fixed. There is also an anterio-posterior cutting guide for the femoral cutting guide.

Description

The invention relates to tibial and femoral cutting guides for installation of a total knee prosthesis.

Various techniques are already known for making a total knee prosthesis, which can be divided into two families. One comprising the femoro-patellar or trochleo-patellar prostheses, consisting of interposing, between the kneecap and the femur, a prosthesis intended to ensure the reconstruction of the corresponding joint, injured by rheumatic or arthritic, traumatic or other injuries, tending to the destruction of the articular surfaces, in particular of the trochlea and sometimes of the patella, leading to pain and functional insufficiency of the knee lock. The prosthesis comprising, in this case, a femoral element, called "trochlea element" and a patellar element, said "medallion", fixed under the patella. The other comprising the total three-compartment prostheses, including the replacement of the tibial plates, intended, mainly, for total reconstructions of the knees after very significant destruction. It is for the installation of prostheses of the second family, that is to say total three-compartment prostheses, such as that shown after installation in FIG. 17 of this application, that the tibial cutting guides are intended and femoral, objects of the present invention.

The prostheses, mentioned above, all require, to allow their installation, specific bone resections.

These resections are carried out with artisanal means, inspired by techniques used in cabinetmaking, using cutting and sighting guides of which there is a great diversity, but none of which really allows to obtain geometrically precise resections, allowing the direct installation of the tibial and femoral parts of the prosthesis with perfect adaptation and without play thereof, while maintaining the tibia its alignment and its natural movement relative to the femur. Indeed, any game, facilitating a relative displacement, even a small one, of the tibial and femoral elements relative to the corresponding resected parts of the tibia and the femur, generally causes suffering, and any defect in alignment, positioning and movement of the shin compared to the femur is a source of discomfort, even physical and aesthetic handicap. However, it is precisely the suffering caused to the person concerned by rheumatic, arthritic or traumatic injuries, and the corresponding physical handicap, that we intend to remedy by installing a total knee prosthesis.

Various means intended to facilitate these resections already exist, such as those described in the following documents.

- European patent application 0 340 176, concerning a device for resection of a femoral bone with a view to the application of a knee prosthesis. This device is intended to facilitate frontal, rear and lateral resections of the head of a femur, for the purpose of applying, on the knee, a joint prosthesis. This device consists essentially of a parallelepiped body, designed to be fixed against the distal parts of the femur, in order to facilitate resection of the femur on the front and on the back, and a second part cooperating with the first, for the execution of transverse resections of the distal parts of the femur. The body is fixed by screws against the distal parts, respecting a very approximate alignment, and the second part is, at no time, fixed directly to the bone, which makes possible relative displacements detrimental to precise cuts.

Nothing is planned for the tibial resections, essential for the installation of a total knee prosthesis.

- patent application PCT / US88 / 01 168. The operating technique, which is mainly in the case of a total knee prosthesis, implements a femoral cutting guide, having great constructive and functional analogies with the cutting guides described in the document analyzed above, and therefore offering the same drawbacks, and a tibial cutting guide, which, if accompanied by a positioning and alignment system, is at no time solidly fixed to the large tibial tuberosity other than by jaws and by a few screws ensuring an indirect vertical positioning, moreover quite summary, and not guaranteeing the absence of relative displacement of the guide during the corresponding resection operation.

- French patent 2,664,157 having as its object a femoral cutting guide. The cutting guide in question is intended to facilitate the execution of all the femoral resections necessary for the implantation of a femoral prosthesis. It mainly comprises a plate, in the middle of which a grooved bore is made, intended to receive a pivot comprising, at its base, a drilling guide orifice, at the upper end, an orifice for the passage of a rod removable guide and, in the middle, a horizontal cutting guide, surmounted by a feeler arm. A vertical cutting guide slides in a transverse hole made in the pivot. The plate has cutting guide grooves. Such a device, although satisfying in principle, is heavy and bulky, which does not make it easy to implement; which is detrimental to the quality of resections performed by this means.

The present invention aims to remedy the drawbacks of similar means currently existing in the prior art, by proposing a set of tibial and femoral cutting guides, making it possible to carry out, on the tibial and femoral ends, without any trial and error or discomfort, joint bone resections, adapted exactly to the shape and dimensions of the corresponding total knee prostheses, ensuring rigorous positioning and fixation of the prosthetic elements, making it possible, in particular, to achieve good leg-ankle-head alignment - femur, ensuring, in particular, very precise cuts, strictly positioned in the three planes of space.

The tibial and femoral cutting guides for installation of total three-compartment knee prostheses, according to the invention, are defined as follows
The tibial cutting guide, comprising a guide forceps connected to an alignment and aiming device, is mainly characterized in that the guide forceps comprises, at its upper part, a removable column, at the end of which is fixed a probe, vertically, a connection orifice to an alignment and aiming device and, laterally, two oblique orifices intended for its attachment to the tibial upper end by means of threaded pins.

The guide davit has upper and lower faces, inclined towards one another, towards the rear, according to two different angles of inclination, according to two predetermined cutting angles.

The height (h), separating the active end of the feeler from the plane (C), passing through the upper face of the forceps, is determined as a function of the height of the bone resection to be performed.

The alignment and aiming device is, according to a first embodiment, consisting of an upright connected, at its upper part, by a crosspiece, to a tibial centromedullary rod and to an external aiming rod, mutually parallel.

The alignment and sighting device is, according to a second embodiment, consisting of an angled rack rod, of rectangular section, connected, by a sleeve with retractable ratchets, to a straight rack rod, of same section, equipped transversely with a feeler finger of adjustable length.

The femoral cutting guide is characterized in that it comprises - a cutting template having, at its base, a femoral probe, in its center, a drilling guide, in its middle, a notch with lateral grooves and, on its sides, orifices allowing its fixing against the femoral epiphysis, by means of threaded pins, - a centro-medullary rod, - a drilling guide with flange, - a plate with longitudinal slot, against the front face of which fixed a removable distal femoral cutting guide, adjustable using a thumbwheel, and a femoral probe surmounting the cutting guide, - an anteroposterior cutting guide.

The width and the thickness of the plate correspond, respectively, to the spacing and the width of the grooves produced in the sides of the median notch of the cutting template.

The longitudinal slot of the plate has a width slightly greater than the diameter of the central medullary rod.

The plate has, on each of its sides, a graduated scale, partially masked by the grooves of the template, the upper edges of which are used as sliders.

The distal femoral cutting guide has, on the front, a vertical transverse groove and, on the rear, two holes for attachment to the femoral epiphysis by means of threaded pins.

The diameter and thickness of the flange of the drilling guide, as well as the outside diameter of the drilling guide itself, are determined so that the said flange can be inserted and slide in one of the grooves in the notch of the cutting template.

The distal cut is adjustable by action on the screw wheel according to the difference between the femoral gap in flexion and the femoral gap in extension.

The advantages obtained, thanks to this invention, consist essentially in that it is suitable for all cuts corresponding to the various total three-compartment knee prostheses, since it is possible, with this, to ensure alignment aiming internal and external with the same cutting guide, while ensuring the measurement of the size of the distal and femoral parts, whatever the size and the axis of the tibia and the femur, the cuts being guided and controlled in the three planes of space.

Other characteristics and advantages will appear in the description which follows of the cutting guides produced according to the invention and of the execution of the resections corresponding to a three-compartment total knee prosthesis, given by way of nonlimiting example, with regard to the attached drawings in which - Figure 1 shows a side view of the cutting guide
tibial, equipped with the centro-medullary guidance device
and the external aiming control rod, - Figure 2 shows a side view of the cutting guide
tibial, equipped with the external guide device, - Figure 3 shows a side view of the cutting guide
tibial, fixed against the upper end of the tibia, with
indication of the cutting plane (C), - Figure 4 shows a side view of the cutting guide
tibial, fixed against the upper end of the tibia, with
representation of the tuning fork chisel used to perform the
vertical section, - Figure 5 shows a top view of the cutting guide
tibial according to Figure 4, - Figure 6 shows a perspective view of
knee joint after tibial resection, in progress
determining the size of the prosthesis using a
template, - Figure 7 shows a side view of the articulation of the
knee according to Figure 6, being determined
the tibio-condylar gap, - Figure 8 shows a perspective side view of the
femoral cutting guide, being placed on
the lower epiphysis of the femur, - Figure 9 shows a perspective side view of the
femoral cutting guide, in place on the femoral epiphysis
lower, - Figure 10 shows a partial front view of the guide
of femoral section, - Figure 1 1 shows a perspective front view of the
distal femoral cutting guide, separate and fixed against
the lower epiphysis of the femur, before performing the
resections, - Figure 12 shows a perspective front view of the
cutting guide according to FIG. 11, after completion of the
distal sections, - Figure 13 shows a side view of the joint in
course of anteroposterior cuts and
anterior and posterior chamfers, - Figure 14 shows a top view of the joint
according to Figure 13, - Figure 15 shows a perspective view of
the knee joint after tibial and femoral resection
final, during verification of the total prosthesis at
using a template, - Figure 16 shows a side view in section of
the joint after placement of the femoral part of
the prosthesis, when finishing with a chisel,
Figure 17 shows a side view in section
longitudinal of the joint with its prosthesis
total three-compartment, in the extended position, - Figure 18 shows a side view in section
longitudinal of the articulation according to FIG. 17, in
bending position.

The figures represent the means according to the invention allowing the installation of a total three-compartment knee prosthesis 10, comprising a total femoral prosthesis 11, a tibial prosthesis 12 and floating meniscus elements 13, adapting to the epiphysis 21 of the femur 20 and on the upper ends 31 of the tibia 30.

The tibial cutting guide 40 comprises a davit 41, with inclined faces 411 and 413, provided with a column 42 supporting a feeler 43 and is connected to an alignment and aiming device 50 comprising an upright 51 connected, by a cross-member 52, to a tibial centro-medullary rod 53 and to an external aiming rod 54, or connected directly to an alignment and aiming device 90 consisting of an angled rod 91 with rack 911, connected, by a sleeve 92 with retractable pawls 921 and 922, to a straight rod 93 with a rack 931, fitted transversely with a feeler finger 94.

The femoral cutting guide 60 comprises a cutting template 61 with a femoral feeler 62 having, in its middle, a notch 63 comprising two parallel lateral grooves 631 and 632 and, on its sides, orifices 612 and 613 allowing it to be fixed against the femoral epiphysis 21 via threaded pins 44; a central medullary rod 64 mounted in a drilling guide 65 with collar 651; a plate 66 with longitudinal slot 661 and graduated scale 662, supporting a distal femoral cutting guide 67, with guide groove 671 and with fixing holes 672, and a feeler 68, mounted orientable or rotating in a sheath 69, of internal section rectangular, arranged above the cutting guide 67. The resections are carried out using a tuning fork chisel 1 and an ordinary chisel 2 and an anteroposterior cutting guide 80, and the installation using templates 3 or 4 and caliber 5.

Now examining the figures in more detail, it can be seen in them that FIG. 1 shows that the cutting guide 40 can be perfectly positioned vertically using the feeler 43 resting on the healthiest side, which gives thus a predetermined cutting height (h) (10 mm for example), and positioned laterally and transversely by intramedullary aiming, with introduction of the tibial centro-medullary rod 53 using the external aiming rod 54, for the maintenance of alignment.

FIG. 2 shows that an anteroposterior slope of a determined angle (5 for example) can be introduced via the alignment and sighting device 90, the length of which can be adjusted by action on the pawls 921 and 922 and the spacing can be obtained by means of the feeler finger 94.

Figures 3, 4 and 5 show that after precise positioning of the cutting guide 40 using the additional devices described above and fixing it by its oblique orifices 412 against the upper tibial end 31 to l With the help of threaded pins 44, a reference resection 311, produced in the plane (C) defined by the upper face 411 or lower 413 of the guide, can be carried out using the tuning fork chisel 1.

Figures 6 and 7 show the precautions that are taken after resection 311 of the upper end 31 of the tibia 30 to determine the size of the corresponding prosthesis, using a tibial test template 3, the pre-spinal surface is leveled to accommodate the yoke of said test gauge 3 in front of the thorny mass and to determine the tibio-condylar distance by using a caliber 5, knee in extension, corresponding to FIG. 7 , or in flexion (not shown).

FIGS. 8 to 10 show the positioning of the femoral cutting guide 60 on the epiphysis 21 of the femur 20, into which the intramedullary rod 64 has been introduced beforehand. The drilling guide 65 with collar 651 is threaded onto the rod 64, after introduction of the said collar 651 into one of the grooves 632 of the notch 63 of the cutting template 61, which is then brought manually into contact with the femoral epiphysis 21 and the anterior cortex 23 thereof. ci, as shown in figure 9.

The plate 66 with a longitudinal slot 661 and with a graduated scale 662 is then introduced into the grooves 631 of the front notch 63 of the cutting template 61, while keeping the latter in support, the femoral probe 68 then comes to be applied to the contact of the femur 20, which precisely positions the distal cutting guide 67, which then suffices to secure to the femoral epiphysis 21 using threaded pins 44 passed through the orifices 672 of the cutting guide 67, after adjusting the length with the wheel 70, before separating it from the plate 66, by action on the screw 71, the threaded end of which emerges from the orifice 673. Previously, the graduation giving the size of the femoral prosthesis is raised on the graduated scale 662 of the plate, the template 61 of which serves as a cursor (size 70 in the example of FIG. 10). As can be seen, it is also possible to adjust, precisely, the distal cut by action on the wheel 70, as a function of the difference existing between the femoro-tibial gap in flexion and the gap in extension.

FIGS. 11 and 12 respectively show the femoral epiphysis 21 provided with the distal cutting guide 67, and the femoral epiphysis 21 after the cutting of the distal part 22 making it possible to obtain a reference surface 211. The saw blade has been, to do this, introduced into the groove 671 of the cutting guide 67, which ensures perfect guidance excluding any trial and error.

FIGS. 13 and 14 show that the cutting guide 80 with pins 81 and handle 82, making it possible to make the anteroposterior cuts and the anterior and posterior chamfers, is then fixed on the surface 211 resulting from the prior distal cutting, by by means of the pins 81. The joining being completed by the addition of the threaded pins 44. This cutting guide 80 being thus fixed, it suffices to make successively the cuts 212 to 215, by passing the saw blade respectively through the slots 83 to 86. The femoral resections essential for mounting the femoral prosthesis are then completed, taking into account the size of the prosthesis recorded on the plate 66 of the guide 60.

Figure 15 shows that before mounting the total prosthesis 10, it is important, first of all, to determine the gain in space resulting from the femoral cuts and to position the test femoral piece to determine the thickness of the upper tibial end on the test template 4. The two tibial anchor holes are then drilled.

FIG. 16 shows that after mounting a trial femoral implant, certain angles 216 are softened with the chisel 2.

Figures 17 and 18 show the total prosthesis 10, consisting of the femoral prosthesis 11, the tibial prosthesis 12 and the floating menisci 13, definitively installed, in the extended position (Figure 17) and in the flexed position (Figure 18) .

As can be seen, the use of these cutting guides 40, 60 and 80 makes it possible to obtain bone resections geometrically adapted to the size of a total prosthesis 10, without risk of introducing play or of misalignment, and that was the goal.

Claims (11)

1. Cutting assembly for installation of a total three-compartment knee prosthesis, comprising a tibial cutting guide and a femoral cutting guide, characterized in that these cutting guides include  a) for the tibial cutting guide  - a detachable column guide davit (42), at the end of which a probe (43) is fixed, vertically, a connection orifice to an alignment and aiming device (50) and, laterally, two orifices obliques (412) intended for its attachment to the upper end (31) of the tibia (30) by means of threaded pins (44),  b) for the femoral cutting guide  - a cutting template (61) having, at its base, a femoral probe (62), in its center, a drilling guide, in its middle, a notch (63) with lateral grooves (631, 632) and, on its sides, orifices (612, 613) allowing it to be fixed against the femoral epiphysis (21) by means of threaded pins (44),  - a central medullary rod (64),  - a drilling guide (65) with flange (651),  - a plate (66) with a longitudinal slot (661), against the front face of which is fixed a distal femoral cutting guide (67), adjustable using a thumb wheel (70), and a femoral probe (68 ) surmounting the cutting guide,  - an anteroposterior cutting guide (80). 2. Cutting assembly according to claim 1, characterized in that the guide davit (41) of the tibial cutting guide has upper (411) and lower (413) faces inclined rearwards, according to two different cutting angles , bone resection to be performed. 3. Cutting assembly according to claim 1, characterized in that the height (h), separating the active end of the feeler from the tibial cutting guide of the plane (C), passing through the upper face of the davit (41), is determined according to the height (h) of the resection to be performed. 4. Cutting assembly according to claim 1, characterized in that the alignment and aiming device (50) of the tibial cutting guide consists of an upright (51) connected, at its upper part, by a crosspiece ( 52), a tibial centro-medullary rod (53) and an external aiming rod (54). 5. Cutting assembly according to claim 1, characterized in that the alignment and aiming device (90) of the tibial cutting guide consists of a counter-bent rod (91) with rack (911), of rectangular section, connected by a sleeve (92) with retractable retractable pawls (921, 922), to a straight rod (93) with rack (931), of the same section, fitted transversely with a feeler finger (94) of adjustable length. 6. Cutting assembly according to claim 1, characterized in that the width and the thickness of the plate (66) of the femoral cutting guide correspond, respectively, to the spacing and to the width of the grooves (631, 632) made in the sides of the middle notch (63) of the cutting template (61). 7. Cutting assembly according to claim 1, characterized in that the longitudinal slot (661) of the plate (66) of the femoral cutting guide has a width slightly greater than the diameter of the central medullary rod (64). 8. Cutting assembly according to claim 1, characterized in that the distal femoral cutting guide (67). comprises, on the front, a vertical transverse groove (671) and, on the rear, two fixing holes (672) to the femoral epiphysis (21), by means of threaded pins (44). 9. Cutting assembly according to claim 1, characterized in that the plate (66) of the femoral cutting guide comprises, on each of its sides, a graduated scale (662), partially masked by the grooves (631, 632) of the template (61), the upper edges of which are used as sliders. 10. Cutting assembly according to claim 1, characterized in that the diameter and the thickness of the flange (651) of the drilling guide (65) of the femoral cutting guide, as well as the outside diameter of the drilling guide itself even, are determined so that said flange (651) can be inserted and slide in one of the grooves (631 or 632) of the notch (63) of the cutting template (61). 11. Cutting assembly according to claim 1, characterized in that the distal cut with the femoral cutting guide is adjustable by action on the thumb wheel (70) of the screw (71) according to the difference existing between the femoral gap in flexion and the femoral gap in extension.