WO2015197800A1

WO2015197800A1 - Device for assisting in positioning an instrument and/or a prosthetic implant, comprising a first three-dimensional guide and a second multifunctional guide

Info

Publication number: WO2015197800A1
Application number: PCT/EP2015/064467
Authority: WO
Inventors: Florian Boucher; Loïc Pinot
Original assignee: Orthonova
Priority date: 2014-06-25
Filing date: 2015-06-25
Publication date: 2015-12-30
Also published as: FR3022764A1

Abstract

The present invention relates to a device comprising a first three-dimensional guide (1) intended to be positioned by clipping on a bone (C) of a patient's joint that is to be restored, and a second guide called a "multifunctional" guide, in which the first guide (1) comprises a body (2), substantially in the shape of a U with a central portion (3) and two flexible branches (4), two drill bushes oriented parallel to the direction of clipping, in which the second guide comprises a cutting guide, a drilling jig and a custom stop, in which the cutting guide comprises a rod of revolution about a third axis, and in which the drilling jig comprises a face extending in a second plane, and in which the surface of the custom stop corresponds to a part of the first contact surface, by translation in the direction of the third axis, either for a first relative position of the first guide and of the second guide, in which position the third axis would be coincident with the first axis and the first plane would be parallel to the second plane, or for a second relative position of the first guide and of the second guide, in which position the third axis would be coincident with the second axis and the first plane would be parallel to the second plane.

Description

DEVICE FOR ASSISTING THE POSITIONING OF AN INSTRUMENT AND / OR A PROSTHETIC IMPLANT COMPRISING A FIRST THREE DIMENSIONAL GUIDE AND A SECOND MULTIFUNCTION GUIDE.

1. Field of the invention

The field of the invention is that of orthopedic surgery. In particular, the invention relates to the field of surgical operations of joints such as the hip involving at least one guide for assisting the positioning of at least one instrument and / or a prosthetic implant.

2. Prior Art

The correct positioning of prosthetic implants is a priority objective when placing a total hip prosthesis because it can prevent complications in the short, medium and long term. This is one of the factors that determines the survival rate of the prosthesis in the long term. The correct positioning must be ensured regardless of the position of the patient and the approach used during the operation.

Patients undergoing operation on a joint such as the hip, compared for example with patients who have undergone such surgery twenty-five years ago, are both younger and more informed. Patients are looking for a perfect or almost perfect functional result. These patients are ruthless in the evaluation of their own results, which represents for the medical profession a considerable challenge.

In addition, the demand of patients has evolved and the establishment of a hip prosthesis for example in a young subject is becoming more frequent, which raises a question about the longevity of implants, given the on the one hand the changes of activity which involve risks, on the other hand the instability and dislocations, in particular in the short term, and finally the wear and osteolysis in the longer term.

To give these patients the result they are looking for, it is first necessary for the orthopedic surgeon to seek an optimal biomechanical restoration of the joint, especially the hip. One of the main objectives when placing a total hip prosthesis for example is, according to the pathology, to restore or correct the position of the center of rotation of the joint to provide optimal functional biomechanics to the patient. Indeed, the position of the center of rotation of the hip will directly influence the kinematics, that is to say the movements, but also the stability of the hip such as joint effort and muscle tension as well as its duration. life, including wear and / or implant conflicts.

Three problems, at the moment, seem to come to the fore:

the equalization of the length of the two limbs less than one centimeter,

- stability of the hip by aiming to eliminate the risk of dislocation. The relationship between the position of the acetabular implant in the pelvis, the position of the femoral stem and the position of the neck of the prosthesis, is the essential factor of the stability of the hip;

the restoration of a good tension between the soft parts, aiming at restoring the femoral offset (or femoral offset), by the combination of the orientation and the variation of neck length of the femoral prosthesis offered by the modular head .

With regard to the operation of the hip, the operative technique and the artificial hip system comprising the femoral implant, the acetabular implant and possibly a modular spherical articular head coming to connect to the end of the neck of the implant femoral, must allow the surgeon to plan and better control the position of the center of rotation common to the femoral implant, the acetabular implant and possibly said modular spherical articular head, the position of the center of rotation defining three main parameters that are offset of the femoral neck or femoral offset or femoral offset, femoral neck height or femoral height in relation to the leg height and the femoral neck version.

FIG. 1 shows a diagram of an unoperated hip joint with the femur F comprising the greater trochanter T and the small trochanter t, the femoral neck C, the femur head G, and, moreover, the pelvis B including the acetabulum still called acetabular cavity A. The femoral head G and the acetabulum A have a common center O _a such that O _a is the anatomical center of rotation of the unoperated hip joint. In Figure 1, shows the anatomical axis of the proximal femur Kl, K2 and the axis of the femoral neck through the center O _is common to the femur head and the acetabulum A. G is pointed out that generally, the anatomical axis of the femur Kl proximal, and the K2 axis of the femoral neck are not concurrent in three dimensions.

FIG. 2 illustrates the femur seen from above in a direction collinear with the axis K1 comprising a distal end J of the femur, at the knee, also called condyles J, with the posterior end of the external condyle J1 and the posterior end of the internal condyle J2. FIG. 2 shows a top view in a direction co-linear with the axis K1 of the reference line H1 passing through the ends J1 and J2 of the condyles J.

FIGS. 1 and 2 show the offset of the femoral neck a or femoral offset or femoral offset as well as the femoral neck height b or femoral height in relation to the height of the leg and the angle c illustrating the version of the cervix femoral or femoral version. In FIG. 2, H2 is the line parallel to H1 serving as a reference for measuring the angle c, in particular anteversion or else retroversion of the femoral neck C. Indeed, in this view from above of the proximal femur in one direction collinear to the axis K1, c corresponds to the angle between H1 and K2.

In the present invention, it seeks to solve problems at the femoral level in particular. In the most complex cases, in particular cases of hip dysplasia (DDH), usually the dysplastic femur is characterized by a narrow, distorted medullary canal and a shorter, more anteverted femoral neck than the normal femur. These morphological changes increase with the degree of deformation and pathologies. For these clinical cases, the use of a standard intramedullary femoral femoral hip prosthesis geometry and the use of standard radiology make it difficult or impossible to plan and control the three main position parameters of the center of rotation defined by the femoral offset a, the femoral height b and the femoral version c.

Various solutions have gradually been made to overcome these anatomical features that pose problems of accuracy of hip prosthesis.

After proposing a cephalic modularity that is widely used today but insufficient in the most complex cases of dysplasia, a metaphyseal-diaphyseal modularity has been proposed, and finally a cervical modularity. Despite the advantages provided by such modular implants, there has been a mechanical wear by friction and release of wear materials in vivo, the rupture of modular necks, or even the dislocation of modular necks.

In order to increase the precision of implant placement and ensure perfect reproducibility of the surgical procedure, navigation, with or without preoperative medical imaging, has developed. Thus, navigation systems allow the surgeon to plan but also optimize intraoperatively the positioning of surgical instruments and / or implants in the surgical field by providing functional biomechanical information such as leg length, femoral offset, femoral version, mobility of the artificial joint.

Nevertheless, navigation generates significant costs in the facilities and this option is not available in all hospitals. Moreover, it generates a complexity and an extension of the intervention and requires a great expertise of the surgeon.

Thus, the orthopedic industry is looking for alternative techniques.

Thus, the use of customized positioning guides, especially for knee surgery, developed from medical imaging of patients and most often made of medical grade polymer resin by printing, is beginning to develop. in three dimensions (3D).

The main purpose of such guides is to be able to position instruments and / or implants with sufficient precision without the inconvenience of navigation.

These custom-made guides, which are increasingly used for knee surgery, are still little used for hip surgery.

An objective of these guides is that their use allows a surgical technique that allows to position at least one instrument and / or prosthesis accurately, just as with a navigation system or a robot.

One advantage of using the guides is that this technique is inexpensive in terms of navigation and particularly affordable for all hospitals, not requiring investment in expensive equipment. In addition, this technique can save considerable time during the operation so that the working time of the operating room staff is reduced at all stages: room preparation, handling of boxes with implants, postoperative treatment of instruments and repackaging. The number of boxes to be sterilized at each procedure can be considerably reduced since the sizes of the instruments and implants are in principle known before surgery and that the surgeon does not need a set of implants and instruments to choose from at the time of the operation.

One of the disadvantages of the known guides is that they are mainly used for the knee but still very little used, as an alternative to navigation, for surgery of the femoral hip, in particular for the case of standard prostheses with intramedullary rod and metaphyseal body .

Patent application CA 2 817 207 discloses a tailor-made guide for the femur and the pelvis. A cutting guide is positioned around a portion of the femur to allow cutting, in particular. 3. Objectives of the invention

The invention particularly aims to provide an effective solution to at least some of these various problems of the prior art.

In particular, according to at least one embodiment, an object of the invention is to provide a device which is easy to use for the surgeon, not requiring on his part a particular expertise.

Another object of the invention is to provide a guide whose positioning is guaranteed, in order to precisely ensure the positioning of the following steps of the operation, in particular the subsequent positioning of surgical instruments such as cutting guides and / or or guides for preparing the interior of the bone, and / or the subsequent positioning of prosthetic implant (s).

In particular, according to at least one embodiment, an objective of the invention is to provide a customized guide that eliminates navigation while ensuring at least the same level of success.

In particular, the object of the invention is, according to at least one embodiment, to provide such a guide for the operation of the hip in semi-active computer assisted surgery, in order to assist in the positioning of hip femoral prostheses. but also for the operation of other types joints and the fitting of other types of prostheses.

Another objective of the invention is, according to at least one embodiment, to provide a guide that makes it possible to facilitate or even ensure the correct positioning of a prosthetic implant according to an orthonormal reference system associated with the position of the center of rotation of the implant. the articulation as predefined by the surgeon and / or the designers and / or manufacturers of the guide.

Another object of the invention is, according to at least one embodiment, to provide such a guide that allows the surgeon to control the position of the center of rotation and the three main parameters that result, namely the femoral offset, the femoral height and the femoral version, during the surgical operation.

4. Presentation of the invention

To solve all or part of the objectives of the invention and other objectives which will appear on reading the description which follows, the invention proposes a device comprising a first three-dimensional guide intended to be positioned by clipping on a bone d a joint to restore a patient and in that it comprises a second guide called "multifunction", wherein the first guide comprises a body, substantially U-shaped having a central portion and two flexible branches extending from either side of the central portion, configured to allow clipping of the first guide around a first portion of a bone in a predetermined clipping direction and a first contact surface, wherein the first guide comprises two barrels drilled parallel to the clipping direction, wherein the second guide comprises a cutting guide, a drilling template and a tailor-made abutment, wherein the two piercing barrels comprise a first revolution drilling barrel about a first axis and a second revolution drilling barrel about a second axis, the first axis and the second axis being contained in a first plane, wherein the cutting guide comprises a rod of revolution about a third axis, and wherein the drilling jig comprises a face extending in a second plane, and wherein the surface of the custom stop corresponds to a portion of the first contact surface. , by translation in the direction of the third axis, ie for a first relative position of the first guide and the second guide in which the third axis coincides with the first axis and in which the first plane is parallel to the second plane, ie for a second relative position of the first guide and the second guide in which the third axis would coincide with the second axis and in which the first plane would be parallel to the second plane.

At least one, especially at least two piercing barrels allows the insertion of reference pins in the bone, including metal. The piercing barrel (s) can be made in one piece with the first guide, or alternatively be attached to the first guide, and form through holes. These holes will allow for example the positioning of one or more reference pins in the bone for the subsequent positioning of tools, for example cutting and / or resurfacing or other.

The drilling guns are for example oriented parallel to the direction of clipping. It should be noted that the orientation of the plane defined by the axes of said at least two piercing guns is generally essential to allow the subsequent obtaining of the planned positioning of the prosthesis and to determine the position of the center of rotation planned by the surgeon. and / or the designer and / or manufacturer of the first guide.

It is understood that the first guide according to the invention is generally a positioning guide, in that it does not consist, preferably, in a cutting guide as such. It generally allows the subsequent positioning, accurate and according to a predefined plan, of one or more instruments for the preparation of the bone such as a cutting guide, a drilling guide, or other.

Thanks to the device according to the invention, the initial prepositioning contact between the first guide and the bone is such that this guide substantially matches the part of the bone against which it comes into contact before clipping in a direction substantially corresponding to the direction clipping. This initial contact makes it possible for the surgeon to self-adjust the position of the guide according to the direction of clipping during the clipping, and consequently a precise or at least relatively precise positioning of the guide when clipped in the direction of clipping.

Thus, it can be considered that the guide according to the invention is intended for marry the bone in at least a relatively precise position around the bone, after clipping, and that before, that is to say before clipping, the guide is intended to be pre-positioned on the bone, in a direction substantially corresponding to the clipping direction.

According to a particular embodiment, the first guide is at least partially made to measure using medical imaging at least three dimensions of the joint, the first guide being configured to substantially match a second predetermined portion of the first contact surface against which it comes into initial contact before clipping in a pre-positioning, substantially in the direction of clipping. Afterwards and for the rest of the description, "the first guide" will be called "the guide".

Thanks in particular to the shape of the outer end of the branches used at the time of pre-positioning substantially in the planned clipping direction, the invention allows use of the guide without training or special expertise of the surgeon. The clipped position is unique and can be obtained relatively precisely after the pre-positioning and self-adjustment of the positioning of the guide during clipping.

The guide may be provided to be clipped onto a bone portion of the bone which is concave or convex, and of substantially elliptical cross section, such as the neck of the femur, in particular.

It should also be noted that, the longer the bone portion is relatively to the average diameter of the elliptical transverse section of said bone portion, the better may be the positioning accuracy of the guide on the bone, once clipped. For example, on a femoral neck, the length of the bone portion may vary between about 10 mm and 40 mm for an average diameter of the elliptical cross section of said bone portion of between about 15 mm and 55 mm. The length may be less than 10 mm or greater than about 40 mm, for other joints than the femoral neck depending on the average diameter of the cross section of the bone portion considered.

The outer end of each branch of the guide is, for example, shaped to conform substantially to a surface portion of the outer surface of the bone in contact with which the guide is pre-positioned before clipping substantially in the direction of clipping. In this case, the pre-positioning is essentially performed on a surface portion and not only a line of contact with the bone, which can further improve the accuracy of the pre-positioning of the guide and therefore the positioning of the guide, once clipped around the bone.

To allow the pre-positioning, the shape of the outer end of each branch is for example substantially identical to the shape of a line or surface portion of the inner surface of the guide body taken from the outer end and going in the reverse direction to the clipping direction.

It should be noted that this inner surface of the particular guide body is intended to marry substantially, when the guide is clipped around the bone, the line or surface portion of the outer surface of the bone in contact with which the guide is pre-positioned.

The inner surface of the guide advantageously comprises two demarcation lines substantially coinciding with the curves of a profile of the bone seen in the direction of clipping.

The clipping interference of the guide may be equal, for each branch, to a distance Ai, greater than 0, between the translation projection of the inner end of the branch on a plane normal to the clipping direction and the projection by translation on said plane of the line of demarcation of the branch.

Ai is greater than 0 to allow a clipping back of the two lines of demarcations visualized in the clipping direction, and less than a theoretical value Ai _max such that the clipping surface of the guide behind the two lines of demarcations visualized in the direction of clipping substantially matches the surface of the corresponding bone on which the guide is clipped. In this extreme case, which would only be possible with a sufficiently flexible material and combined with suitable geometrical thicknesses of the guide, it is possible, for example, to evaluate Ai _max as a function of half of the minimum average distance measured in the direction perpendicular to the direction of clipping between the lines of demarcation over the entire height of the guide. Ai may for example be greater than or equal to 0, in particular greater than or equal to 0.1 mm, in particular greater than or equal to 0.5 mm, even greater than or equal to 1 mm, or greater than or equal to 2 mm, for example being greater than or equal to 5 mm, in particular between 0 mm and 5 mm, for example between Approximately 0.1 mm and 5 mm, for example between 0.1 mm and 3 mm, in particular between 1 mm and 3 mm approximately.

The minimum pre-positioning interference of the guide may be equal, for each branch, to the distance between the projection by translation of the outer end of the branch on a plane normal to the direction of clipping and the projection by translation on said plane of the demarcation line of the branch, the minimum interference pre-positioning of the guide being between 0 and Ai, in particular between Δί / 4 and Ai, or between Δί / 2 and Ai about.

In a particular embodiment, the minimum prepositioning interference may be close to or even equal to Ai.

The values of the clipping interference and the minimum pre-positioning interference are chosen in particular so as to ensure fixed and solid positioning of the guide once clipped. These values are chosen inversely to take into account also the effort to be provided by the surgeon to allow clipping of the guide around the bone and will depend on multiple factors, including the mechanical properties of the material of realization of the guide, the thicknesses of the flexible branches of the guide.

It should be noted in fact that the thickness of the guide may in particular be adjusted to play on the geometric flexibility sought.

Throughout the height of the guide and the bone portion around which the guide is clipped, the distance d3, measured in the clipping direction between the outer end of each branch and the line or surface portion of the outer surface of the os located first in the clipping direction for this branch, for example is greater than an Ad value at the maximum distance between:

the distance d1, measured in the direction of clipping, between firstly the inner end of a first of the two branches of the guide body and, on the other hand, the corresponding line or surface portion of the outer surface of the 'os located first according to the clipping direction, and

the distance d2, measured in the direction of clipping, between firstly the inner end of the second of the two branches and secondly the corresponding line or surface portion of the outer surface of the bone located first according to the clipping direction,

or d3 = max (Ad + max (dl, d2)), evaluated on the height of the guide and the portion of the bone receiving the guide in the clipped position around the bone, with Ad> 0.

With this aspect of the invention, the outer ends of the branches of the guide body are in front of the inner ends of the guide body legs of a minimum value of Ad, such as Ad> 0.

The guide can be used for femoral surgery and have a height such that it can substantially cover the femoral neck surface from the base of the cervix above the metaphysis to the end of the cervix below. the femoral head out of the cartilage area.

Indeed, the higher the height of the guide, the better the positioning accuracy of the guide. More specifically, and as indicated above, the longer the bone portion is relatively to the average diameter of the elliptical cross section of said bone portion, better can be the positioning accuracy of the guide on the bone, once clipped. For example, on a femoral neck, the length of the bone portion may vary between about 10 mm and 40 mm for an average diameter of the elliptical cross section of said bone portion of between about 15 mm and 55 mm. The length may be less than 10 mm or greater than about 40 mm, for other joints than the femoral neck depending on the average diameter of the cross section of the bone portion considered.

The bone may have a substantially concave or convex shape. In this case, thanks to the concave or convex shape of the bone, any longitudinal translation of the guide substantially along the longitudinal axis of the bone, is blocked when the guide is clipped around the bone.

Moreover, the bone may have a substantially elliptical cross-sectional shape. In this case, the substantially cross-sectional shape elliptical of the bone, over substantially the entire height of the portion of the bone around which the guide is positioned after clipping, to block in rotation the guide according to the invention, when properly positioned and clipped on the bone.

The guide having been designed and manufactured with reference to the positioning mark of the prosthesis in the bone associated with the center of rotation planned by the surgeon and / or designer and / or manufacturer of the guide, any point of the guide once positioned and clipped on the bone becomes a reference on the bone and makes it possible to determine with good precision, intraoperatively, the positioning mark of the prosthesis associated with the center of rotation planned by the surgeon and / or designer and / or manufacturer of the guide.

The guide may comprise a visual and / or mechanical polarizer configured to prevent the practitioner from positioning the guide upside down on the bone.

Such a visual and / or mechanical polarizer may for example be in the form of the three-dimensional representation of the neck and the articular head of the integrated prosthesis in the design of the guide on the outside thereof, so as to allow only one direction of positioning of the guide to measure, with for example the keyed up to the top of the neck of the femur towards the head of the femur. In a particular example, said three-dimensional representation can not be positioned downwardly without interfering for example with the external metaphysis of the proximal femur thus preventing the clipping of said guide on the neck of the femur.

The guide body may have at least one slot located near an upper or lower edge of the guide.

At least one of the branches may comprise at least one slot opening, or not, at the inner and outer end of said branch.

The presence of such slots, generally horizontal, that is to say substantially parallel to the upper and lower edges of the guide, can absorb the inaccuracies of the guide by forming areas of local geometric flexibility around these slots. Such inaccuracies may be due on the one hand to the processing of the image allowing the realization of the guide and on the other hand to manufacturing tolerances of the guide. Thus, in particular, since these inaccuracies are of isotropic nature, the presence of horizontal slots in the guide near the upper and / or lower edges makes it possible, for example, locally deforming, self-locking and self-adjusting positioning along the longitudinal axis in a predetermined position, compensating for inaccuracies in the design and manufacture of the guide.

The number of these slots may be greater than one, especially between two and twenty, for example between two and ten. The disposition of these slots can be extended over all the contours of the guide.

The presence of slots opening, that is to say extending to the inner and outer end of each branch can improve the flexibility of clipping branches.

Of course, it is possible to combine these two types of slots.

It should also be noted that, in addition to the local geometric flexibilities previously described, the guide may have a modularity of flexibility by the choice of material and the choice of the geometric rigidity of the guide, related to its thickness, to the section of the branches, to the length of the branches, etc.

The guide may further include a clearance notch along one or each demarcation line. Such a release notch can help to maintain the position of the guide once clipped, and prevent its unclipping, especially in the case where the guide manufactured, because of inaccuracies in design and / or manufacturing, would be too tight around the bone.

The guide may include an extraction system configured to allow the extraction of the guide out of the bone, including a threaded hole on the guide configured to allow the screwing of a metal extraction rod.

Such an extraction system can be used to extract the guide out of the bone, for example once the pins are placed and traversing all or part of the bone.

The guide may include a drill guide or means for connection to a drill guide, in particular for a resurfacing operation of the femoral head.

According to another aspect, the subject of the invention is a method of designing and custom manufacturing a guide as defined above. This method may especially comprise at least some of the following steps, and advantageously all:

- Perform a three-dimensional medical imaging of a bone of a joint, including more generally a bone region of a bone articulation to operate, and deduce the three-dimensional shape of an outer surface of the bone that an inner surface of the guide must substantially marry.

- Determine a center of rotation of the joint to be restored, in particular using anatomical references visible on medical imaging in three dimensions,

Determining an orthonormal coordinate system associated with said center of rotation and a clipping direction, in particular such that one of the direction vectors of the orthonormal coordinate system is collinear with the clipping direction and that the planned position of the prosthesis to be implanted is unique relative to this landmark,

- Deduce the curves of a profile of the bone seen in the direction of clipping, and lines of demarcation of the guide coinciding substantially with said curves of the profile of the bone seen in the direction of clipping,

- determining, for each branch of the guide, an inner end belonging to the inner surface and an outer end not belonging to the inner surface, said outer end having a shape to fit substantially at least one predetermined line of the outer surface of the bones in contact with which the guide is pre-positioned before clipping,

- Realize the guide thus determined for example using a three-dimensional printer (3D), in particular flexible medical grade material, for example medical grade polymer resin.

The method may further include the step of determining an inner surface of the guide body substantially conforming to the corresponding outer surface of the bone after the guide clipped around the bone, including including the lower and upper edges of the guide , also called distal and proximal edges, respectively, as regards the neck of the femur, thus defining a height such that the guide can substantially cover the femoral neck surface from the base of the cervix above the metaphysis to the end of the cervix below the femoral head out of the cartilage area.

Thus, thanks to the invention, it is possible to produce a guide that allows to ensure the surgeon a relatively accurate positioning guide without expertise. This makes it possible to reduce the operating time, to secure the results of the surgical operation and potentially to reduce the total cost thereof, for example by making it possible to extend the life of the prosthesis in vivo thanks to better positioning. prosthesis avoiding or delaying the medical costs associated with the resumption of clinical failure and / or complications that may follow a clinical failure.

The guide can be made with oriented drilling guns, in particular in the clipping direction, so as to allow the subsequent obtaining of the planned positioning of the prosthesis and to determine the position of the center of rotation planned by the surgeon and / or the designer and / or manufacturer of the guide.

According to yet another aspect, the subject of the invention is a method of using a guide as defined above during an operation of a joint of a patient. This method may especially comprise at least some of the following steps, and advantageously all:

- Preposition the guide substantially in the clipping direction so as to substantially coincide the shapes of the outer end of the branches of the guide and the line or surface portion of the outer surface of the bone against which the guide comes into contact ,

- Clip the guide around the bone substantially in the direction of clipping.

In addition to the pre-positioning, the branches of the guide body provide during clipping a self-adjustment of the positioning of the guide in the planned clipping direction and consequently a relatively precise clipped position and unique to the bone.

According to yet another object, the subject of the invention is a method for preparing the femur of a patient before receiving a prosthetic implant. This method may especially comprise at least some of the following steps, and advantageously all: Position the guide as defined above around the neck of the femur, following the steps of the method of using a guide as defined above, the guide comprising at least two piercing guns, the axes of which preferably define a predefined single plan,

- Fixing pins in the neck of the femur through the drilling barrels, and preferably the entire neck of the femur, the diameter of the pin being substantially equal to the inner diameter of the corresponding drilling barrel,

- Remove the guide while leaving the pins in the neck of the femur, - Make a bore in the neck of the femur being guided by one of the pins, using a reamer, including hollow and which comprises itself a bore of a diameter substantially equal to the diameter of said pin,

- Remove said pin, in particular using the reamer during the boring operation of the femoral neck,

- Position in the bore of the neck of the femur and taking support on the other of the pins, a guide of first cut,

- Make a cut of the femur neck according to the first cut guide to define a first cut surface,

- Remove the first cut guide.

The method may further include the steps of:

- Position using the bore in the neck of the femur a multifunctional guide comprising a caliber of preparation of the inside of the femur and a second cut guide, in particular so that a lower surface of the caliber of preparation comes resting on the surface of the first cut, - Prepare the inside of the femur with the help of the preparation gauge, in particular in order to prepare the anchoring of the prosthesis to be implanted in the femur,

- Make a second cut using the second cut guide, in particular to form a second cut surface on which will support a prosthetic implant.

The multifunction guide may comprise a stop made to measure, intended in particular to come into contact with a predetermined surface of the bone in the direction of clipping, configured in particular to center the template or template preparation on the first cut surface.

By "inside of the femur" it is necessary to understand the inside of the neck of the femur and / or the inside of the metaphysis or even the inside of the femoral stem beyond the metaphysis.

The template or template may comprise a drilling template, in particular, and / or a template for guiding at least one instrument for preparing the interior of the femur, this instrument being rectilinear and / or curved and of constant section or evolutive, said instrument being generally made of a metallic material.

The invention particularly relates, independently and / or in combination with the foregoing, to a multifunctional guide for preparing the interior of the femur and cutting, in particular of the second section, comprising:

a template or preparation template, in particular a metal template, a cutting guide, in particular a metal guide, for example a V-shaped or horizontal guide, or an inverted V-shaped guide,

a stop made to measure, for example using a three-dimensional printer (3D), in particular a medical grade resin-type polymer material or any other medical grade material, configured to assemble the template or template preparation and the cutting guide between them.

The stop is configured to allow locking in translation of the multifunction guide on the axis comprising the clipping direction, to center the template or template preparation on the patient's bone. The preparation of the interior of the femur is intended to prepare this region of the bone so as to allow the reception and / or fixation of a prosthesis with or without intramedullary rod.

The stop is also configured to allow two different assemblies of the template or template preparation and cutting guide, depending on whether the approach is anterior or posterior.

An advantage of such modularity is to reduce the number of elements required in the instrumentation kit to cover a full range of implants. The multifunction guide can be made in one piece to measure. Alternatively, the multifunction guide can be made in three parts (template or template preparation, cutting guide and stop) assembled. The multifunctional guide advantageously comprises means for anchoring in the bone, in particular a pin adjusted to the bore made in the bone. The anchoring means may be carried for example by the cutting guide.

The template or preparation template advantageously makes it possible to prepare the positioning of a prosthesis and possibly to prepare different zones for anchoring this prosthesis inside the femur.

The cutting guide of the multifunctional guide advantageously makes it possible to make a cut as accurate as possible directly in relation to the preparation of the interior of the femur made with the template or template preparation. When the multifunction guide is used with the abutment which comes into contact with the bone in the clipping direction, the section, for example V-shaped, made according to the cutting guide of the multifunction guide can set a reference on the longitudinal axis of positioning of the prosthesis. This amounts to precisely controlling the center of rotation of the joint, in particular the femoral joint, which will be obtained after the placement of the prosthesis in the bone and possibly in combination with the use of an adapted modular articular spherical head coming from connect to the end of the neck of the femoral implant.

The invention further provides, in combination with the foregoing, a method of resurfacing the femoral head of a patient prior to receiving a femoral resurfacing prosthetic implant, comprising the steps of:

Position the guide as defined above around the neck of the femur, following the steps of the method of using a guide as defined above, the piercing guide comprising or being configured to receive a piercing gun positioned on the top of the head of the femur,

- Fix a pin in the femoral head and the femoral neck using the drill barrel,

- Remove the guide leaving the pin in place,

- Arrange a resurfacing tool using the pin in place.

The subject of the invention is also, in combination with the foregoing, a method for preparing the femur of a patient before receiving an implant. prosthetic, comprising the following steps:

- Position by clipping the guide as defined above around the neck of the femur, by following the steps of the method of use of the guide as defined above, the guide comprising at least two drilling guns, in particular whose axes define a predefined single plan,

- Fix pins preferably through the entire neck of the femur through the drilling barrels, the diameter of the pin being substantially equal to the inner diameter of the corresponding drilling barrel,

- Remove the guide while leaving the pins in the neck of the femur,

- Position a cutting guide using the pins in place for resection of the cervix and / or part of the metaphysis.

5. List of figures

Other features and advantages of the invention will appear on reading the following description of particular embodiments, given by way of a simple illustrative and nonlimiting example, and the appended drawings in which:

- Figure 1 illustrates, schematically and partially, in front rear view, the hip joint;

Figure 2 schematically and partially shows a top view of the femur;

Figure 3 is a front view, schematic and partial, of a proximal femur illustrating the predictive positioning of a guide according to the invention;

Figure 4 illustrates the proximal femur, as in Figure 3, but in lateral saggital view;

Figure 5 is a view similar to Figures 3 and 4, in front rear view;

Figure 6 is a schematic proximal view in cross section along the longitudinal axis X of the femoral neck and AA of Figures 3 to 5; Figure 7 schematically illustrates a cross section of a bone such as the neck of the femur, representing the locating points for the purpose of custom-made guide according to the invention;

FIG. 8 is a diagrammatic and partial view, seen in cross section, of the femoral neck bone of FIG. 7 on which the guide according to the invention has been prepositioned;

Figure 9 is a schematic and partial view, in cross section, of the femoral neck bone and the guide of Figure 8, the guide being clipped around the bone of the femoral neck;

Figure 10 shows schematically and partially, in perspective, a femoral neck bone provided with the guide according to the invention seen in the clipping direction;

Figures 11 to 14 are schematic and partial cross sections respectively according to A-A, B-B, C-C and D-D of Figure 10, the guide being in the position of pre-positioning;

Figures 15 to 18 are schematic and partial sections along A-A, B-B, C-C and D-D of Figure 10, once the guide clipped around the bone of the neck of the femur;

Figures 19 to 21 are schematic cross-sectional views of an example of femoral neck bone around which is clipped a guide according to the invention according to different ways of approach and clipping directions;

Figure 22 is a schematic front view in front of a femoral neck bone provided with a guide according to the invention, the guide being provided with a polarizer;

FIG. 23 illustrates the femoral neck bone provided with the guide and the keying device of FIG. 22 in side view;

FIGS. 24A and 24B schematically and in isolation illustrate, in perspective, an exemplary guide according to the invention, seen from the inside and the outside respectively;

Figures 25 to 27 show in isolation, schematically and in perspective, other examples of guides according to the invention;

Figures 28 to 31 show diagrammatically and in perspective, a bone of the femur neck undergoing different stages of a method surgical operation using the guide according to the invention;

Figures 32 and 33 show schematically and partially in perspective, the installation of a multifunction guide after a method of using the guide, for example the method illustrated in Figures 28 to 31;

- Figure 34 is a top view, schematically and in perspective the multifunctional guide of Figures 32 and 33, positioned for drilling in an anterior approach way;

Fig. 35 is a view similar to Fig. 34, the multifunctional guide being positioned for drilling in a posterior approach;

FIG. 36 illustrates the multifunctional guide of FIGS. 34 and 35 in diagrammatic perspective exploded view;

Fig. 37 illustrates in isolation the multifunctional guide of Fig. 36 schematically in perspective view together for an anterior approach way; Figure 38 illustrates schematically and in perspective the multifunctional guide of Figure 36 in schematic view and semi-exploded perspective for a posterior approach;

Fig. 39 illustrates the multifunctional guide of Fig. 38 schematically and in perspective view;

Figure 40 schematically illustrates in perspective the use of the multifunctional guide of Figures 32 to 39 for sectioning the femoral neck bone;

FIGS. 41 to 45 schematically, partially and in perspective show a femur bone during various stages of a surgical procedure for setting a pin for re-surfacing the femoral head, using a guide according to the invention;

Figures 46 to 49 show schematically and partially, in perspective, a femur bone according to different steps of cutting the neck of the femur using the guide according to the invention. 6. Description of particular embodiments

Figures 1 and 2 have already been commented.

Figures 3 to 6 illustrate the proximal portion of a femur bone representing the femoral head G, the femoral neck C, the greater trochanter T, the small trochanter t. Diagrammatically and in dotted lines, the guide 1 (first guide in the claims) according to the invention clipped on the neck of the femur.

As shown in dashed lines, the guide 1 comprises a U-shaped body 2 comprising a central portion 3 and two branches 4, in particular 4a and 4b, flexible, extending on either side of the central portion 3 and configured to allow clipping of the guide 1 around a portion of the bone in a predetermined clipping direction z ■

According to the invention, the guide is configured to substantially match a predetermined portion of outer surface S of the bone against which the guide comes into initial contact before clipping in a pre-positioning substantially in the clipping direction ^z , as will be described later.

It should be noted that the guide 1 does not require for its positioning around the bone fastening means such as screws. The only clipping of the guide around the bone allows it a firm hold in predefined position.

The body 2 of the guide 1 extends between a lower edge 5 (or distal edge in this case of the neck of the femur) and an upper edge 6 (or proximal edge in this case of the neck of the femur). In the illustrated example and as visible in particular in Figure 3, the lower edge 5 extends in the immediate vicinity of the base j of the neck of the femur above the metaphysis and the upper edge 6 is in the immediate vicinity of the edge g at the end of the cervix below the femoral head off cartilage area.

The body 2 of the guide 1 has an inner surface 10 in contact with the bone configured to substantially match the shape of the outer surface S of the bone against which the guide 1 is intended to be positioned. The body 2 of the guide 1 also has an outer surface 11 not in contact with the bone once the guide 1 clipped around the bone.

The inner surface 10 of the body 2 of the guide 1 comprises two demarcation lines 13 and 14 coinciding substantially respectively with the curves u and v of a profile of the bone seen in the clipping direction z ■

The clipping direction z and the center of rotation O to be restored are predefined by the surgeon and / or the designers or manufacturers of the guide 1 in a preoperative phase. An orthonormal coordinate system (0, x, y, z) is associated with the center of rotation O such that the directional vector z is collinear with the clipping direction and such that this marker uniquely determines the planned position of the prosthesis to implant. The longitudinal axis X collinear with the vector x corresponds to the longitudinal axis of positioning of the prosthesis.

With reference to FIGS. 7 to 9, in particular to FIGS. 8 and 9, on which we can see an example of a guide 1 according to the invention seen from above in cross-section, it may be noted that the branches 4 present each an inner end, respectively 20 and 21, this inner end 20, 21 belonging to the inner surface 10 of the body 2. The branches 4 also have an outer end 22 and 23 respectively, belonging to the outer surface 11 of the body 2.

The outer end 22 and 23 of each branch 4 is shaped to fit substantially at least one predetermined line of the outer surface S of the bone in contact with which the guide 1 is pre-positioned before clipping, substantially in the clipping direction .

In particular, the outer end 22 and 23 of each branch 4 (4a or 4b) is shaped to fit substantially a line of the outer surface S of the bone C in contact with which the guide 1 is pre-positioned before clipping substantially in the direction of clipping, as shown in Figures 7 to 9.

In a particular embodiment not illustrated, the outer end

22 and 23 of each leg 4 is shaped to conform substantially to a surface portion of the outer surface S of the bone C in contact with which the guide 1 is pre-positioned before clipping substantially in the clipping direction.

It should be noted that, in FIGS. 7 to 9, there is shown a cross section of the neck C and / or of the guide 1 along the longitudinal axis X so that only one point of the outer end 22 or 23 is visible, referenced A6 and B6 in these figures, but in reality these outer ends 22 and 23, as well as each point of the guide illustrated in these figures, are part of a three-dimensional curve extending over the entire height of the guide 1 between the upper edges 6 and lower 5 and along the longitudinal axis X. In other words, the reference points and the guide 1 are constructed directly in three dimensions. Each reference point shown in the illustrated two-dimensional diagrams corresponds in reality to a three-dimensional curve which connects all these reference points along the longitudinal axis X. In the example illustrated, the shape of the outer end 22 and 23 of each leg 4 is substantially identical to the shape of a line 24 and 25 (or surface portion in another embodiment not shown) of the surface. inner 10 of the body 2 of the guide 1 taken in the reverse direction to the direction of clipping. If we look at FIGS. 7 to 9, this line 24 and 25 (or surface portion) of the inner surface 10 of the body 2 of the guide passes through the point A4 for the outer end 22 and the point B4 for the outer edge 22. outer end 23.

As can be seen in Figures 8 and 9, the method of using the guide 1, during the operation of a patient's joint, comprises the following two steps. The first step is the pre-positioning of the guide 1, as illustrated in FIG. 8, so as to substantially coincide respectively with the shapes of the outer end 22 and 23 of the branches 4 of the guide 1 and of the line L1 and L2 (FIG. or surface portion in another embodiment not shown) of the outer surface S of the bone against which the guide 1 comes into contact, substantially in the direction of clipping. The second step consists in the clipping of the guide 1 around the bone in the clipping direction to the clipped position illustrated in FIG. 9. The initial pre-positioning contact between the guide and the bone such as the guide substantially matches the portion of the bone against which it comes into contact before clipping substantially in the clipping direction, ensures the surgeon self-adjustment of the position of the guide in the clipping direction during clipping, and by consequent way of positioning the guide once clipped in the direction of clipping.

The clipping interference of the guide 1 is equal, for each branch 4, to a distance Ai, illustrated in FIG. 7, between the projection by translation of the inner end 20 (point A8), respectively 21 (B8) on a normal plane to the direction of clipping (see Figure 7: A7 and B7) and the projection by translation on said plane of the demarcation line 13 or 14 (projection A2 and B2 points Al and Bl corresponding to the lines of demarcation 13 and 14 in the direction of clipping) of the branch 4. Ai is greater than 0, which ensures a clipping back of the two demarcation lines displayed in the clipping direction. Ai is less than a theoretical value Ai _max such that the clipping surface of the guide behind the two demarcation lines visualized in the clipping direction substantially matches the outer surface of the corresponding bone on which the guide 1 is clipped.

Still in the example illustrated in FIGS. 7 to 9, the minimum pre-positioning interference of the guide 1 is equal, for each branch 4, to the distance between the projection by translation of the outer end 22 and 23 of the branch 4 on a plane normal to the direction of clipping and the projection by translation on said plane of the demarcation line 13 or 14 (points Al and Bl) of the branch. The projection by translation of the outer end 22 and 23 of the branch 4 on a plane normal to the clipping direction corresponds in the example shown at points A3 and B3. The projection by translation on said plane of the demarcation line 13 or 14 corresponds in the example illustrated at points A2 and B2.

The minimum interference pre-positioning of the guide is greater than 0 and can be between Δί / 4 and Ai, or even between Ai / 2 and Ai.

Thus, thanks to the invention, the pre-positioning is adjusted before and during the clipping, which secures the internal positioning by clipping the guide.

An advantage of the invention is that the surgeon does not have to be particularly trained to use the guide. It suffices to pre-position the guide correctly in the direction of clipping and then to clip it in the clipping direction to have a guide 1 arranged relatively accurately around the bone C.

It should be noted that the design presented does not imply any particular constraints on the outside of the guide 1, apart from the outer ends 22 and 23 when they form a surface, the thickness can therefore be generally adjusted freely to play on geometric flexibility.

With reference to FIG. 7, in this figure illustrating a particular section of the femoral neck perpendicular to the axis X and in order to receive the guide in the clipped position, it can be seen that the distance d3, measured in the direction of clipping, of the outer end 22 or 23 (point A6 or B86) and the line (or surface portion) (point A4 or B4) of the outer surface S of the bone located first in the clipping direction, for each branch 4 , is greater than a value of Ad at the maximum distance between:

the distance d1, measured in the clipping direction, between, on the one hand, the inner end 20 (point A8) of a first of the two branches 4 and, on the other hand, the line (or surface portion) (point A4 ) of the outer surface S of the bone located first in the clipping direction, and

the distance d2, measured in the clipping direction, between the inner end 21 (point B8) of the second of the two branches 4 and, on the other hand, the line (or surface portion) (point B4) of the surface S exterior of the bone located first in the clipping direction,

or d3 = max (Ad + max (d1, d2)), evaluated on all the cross sections perpendicular to the X axis of the portion of the bone receiving the guide in the clipped position around the bone.

In the example shown and on this cross section, d2> dl, so d3 = Ad + d2.

Of course, Ad> 0.

This ensures that the outer ends 22 and 23 (points A6 and B6) are ahead of the inner ends 20 and 21 (points A8 and B8).

An example of a femoral neck provided with a guide 1 according to the invention is illustrated in FIGS. 10 to 18.

In this example, the guide 1 according to the invention is configured to extend over such a height that it can substantially cover the surface of the neck of the femur C, from the base of the neck above the metaphysis to the end of the cervix below the femoral head off cartilage area.

It should also be noted that, the longer the bone portion is relatively to the mean diameter of the elliptical transverse section of said bone portion, the better may be the positioning accuracy of the guide on the bone, once clipped. For example, on a femoral neck, the length of the bone portion may vary between about 10 mm and 40 mm for an average diameter of the elliptical cross section of said bone portion of between about 15 mm and 55 mm. The length may be less than 10 mm or greater than about 40 mm, for other joints than the femoral neck depending on the average diameter of the cross section of the bone portion considered. In this case, the bone portion of the femoral neck is substantially concave but it is not beyond the scope of the invention if the bone portion on which the guide is intended to be positioned by clipping is substantially convex. The bone has substantially elliptical X-axis cross-sections in this example.

FIGS. 10 to 18 notably make it possible to visualize the shape three-dimensional guide three-dimensionally matching the shape of the outer surface S of the bone, in this case the neck of the femur, around which the guide 1 is clipped.

As illustrated in Figures 19 to 21, the guide 1 can be custom made to suit other routes and other directions or predefined clipping directions.

The design of the guide 1 makes it possible to control the interference of clipping and pre-positioning desired as well as the anatomical support lines or surfaces of the guide 1 on the neck of the femur.

In order to guarantee the same sensations in use for any guide 1, the guide 1 may for example be clipped with an identical range of efforts, regardless of the geometry of the thigh neck or the bone concerned. and / or the approach path taking into account the minimum prepositioning interference, the pre-positioning surface (friction) and the clipping interference.

FIGS. 22 and 23 show a guide 1 in a clipped position on the neck of the femur of a patient comprising a polarizer 30 preventing the surgeon from making a mistake in the direction of positioning of the guide along the longitudinal axis X. In In this illustrated example, the polarizer 30 consists of the integration during the design of the guide of a shape representing the neck of the prosthesis and the articular head. In a non-illustrated example, the polarizer 30 is made in one piece with the guide 1. The polarizer 30 may in another example be configured to interfere with the positioning of the guide 1 if it is positioned upside down on the collar. The polarizer 30 is thus mechanical and / or visual. Thus, the surgeon can not be mistaken for the positioning direction of the guide 1.

In the embodiment illustrated in Figs. 24A and 24B, the guide 1, shown in isolation, has two piercing barrels 35 for subsequent insertion of reference pins placed in the bone. In this example, the drilling guns are oriented parallel to the clipping direction and each have a through opening 36, one end of which is visible in FIG. 24A in particular. The guide having been designed and manufactured with reference to the positioning mark of the prosthesis in the bone associated with the center of rotation planned by the surgeon and / or the designer and / or the manufacturer of the guide, any point of the guide once positioned and clipped on the bone becomes a reference on the bone and can determine with good accuracy intraoperatively the positioning of the prosthesis associated with the center of rotation planned by the surgeon and / or designer and / or manufacturer of the guide.

The orientation of these drilling guns is therefore directly related to the center of rotation 0 of the chosen prosthesis and the planned positioning of this prosthesis in the bone, the correct positioning of the guide 1 ensuring the proper positioning of the drilling guns 35, necessarily , and therefore reference pins which will be introduced into the through opening 36.

The drilling guns 35 may be an integral part of the guide 1, being made in one piece with the guide 1, or, alternatively, be provided to be attached to the guide 1.

In this Figure 24A or 24B also can be seen near the upper edges 6 and lower 5 of the guide 1 a plurality of slots 40 substantially parallel to the edge near which they are arranged, four in this example. These slots, which are substantially horizontal, allow, by locally deforming, to absorb certain inaccuracies in the design and manufacture of the guide 1. Such inaccuracies may be due on the one hand to the processing of the image making it possible to produce the guide 1 and on the other hand In particular, since these inaccuracies are of isotropic nature, the presence of horizontal slots 40 in the guide near the upper and lower edges makes it possible, for example, by deforming locally, to ensure self-locking and self-adjusting positioning along the longitudinal axis X in a predetermined position, compensating for inaccuracies in the design and manufacture of the guide 1. The number of these slots 40 may be variable. Their position may be close to the ends of the branches 4 of the guide 1 as illustrated in FIG. 24A or 24B or may be more numerous and lie along the set of upper edges 6 and lower 5 of the guide 1, as shown in FIG. is the case illustrated in Figure 25.

Still in FIG. 24A or 24B, the illustrated guide 1 has clearance notches 33 extending over the height of the guide 1 and lying on the inner surface 10 of the body 2 of the guide at the demarcation lines 13 and 14. These clearance notches 33, only one of which is visible in FIG. 24A, allow to promote the retention in position of the guide 1 once clipped, and to prevent its unclipping, especially in the case where the guide 1 made to measure, because of inaccuracies in design and / or manufacturing, would be too tight around the bone. It should be noted that, in this embodiment with the presence of the clearance notches 33, they are placed at the demarcation lines 13 and 14, so that the lines of demarcations 13 and 14 are virtual in this case and form imaginary lines that would be present on the inner surface 10 of the body 2 of the guide 1, if the clearance notches 33 were not present.

In FIG. 24B, there can be seen an extraction system 68 configured to allow the extraction of the guide 1 out of the bone, consisting in this example of a threaded hole on the guide 1 configured to allow the screwing of a rod metal extraction.

The branches or clipping lugs 4 may comprise at least one, and as illustrated in FIG. 26, a plurality of slots 45 extending to the inner and outer ends of each branch 4 so as to increase, and in particular to adjust , the flexibility of the branches 4. In fact, these slots 45 opening on the ends of the branches 4 allow to improve this flexibility. In a non-illustrated example, the slots 45 are non-emergent at the end of each branch 4.

In the example illustrated in FIG. 27, the guide 1 cumulatively comprises slots 40 that are substantially parallel to the lower and upper edges 5 and 6 and also slots 45 opening onto the ends of each branch 4.

Of course, in order to facilitate clipping, in addition to the local geometric flexibilities illustrated in FIG. 24 to 27, the guide 1 may be more or less flexible in a global manner depending on the material producing the guide 1 and / or the geometrical rigidity. of the guide 1, in particular its thickness, the section of the branches 4, the length of the branches 4, etc.

To custom-manufacture a guide 1 according to the invention, it is possible to implement the following steps of a method of designing and manufacturing guide 1.

First of all, a three-dimensional medical imaging of the joint or generally of a region of the joint to be operated which for example for the hip joint can include the pelvis or part of the pelvis, the proximal femur to operate, for example the contralateral femur, the distal part the femurs or femurs called condyles. All of this information is for example used to perform a preoperative 3D planning and thus determine a target 0 center of rotation to restore to establish or restore optimal functional biomechanics with the prosthesis envisioned.

It is then of interest, for example, to the thighbone of the hip to be operated, and the three-dimensional shape of an outer surface S of the bone is deduced therefrom that an inner surface 10 of the guide 1 must substantially match. Said surface S of the bone contains the upper and lower edges 6 and 5, also called proximal end and distal end boundary curves on the bone, such that the guidel can substantially cover the surface of the femoral neck since the base of the cervix above the metaphysis to the end of the cervix below the femoral head out of the cartilage zone.

An orthonormal frame (O, x, y, z) associated with said center of rotation O is determined such that the direction vector z of this orthonormal frame is collinear with the clipping direction and such that the orthonormal frame uniquely determines the position planned prosthesis to implant in the bone,

We deduce the curves of a profile of the bone C seen in the clipping direction z and the two lines of demarcation 13 and 14 of the guide 1 coinciding substantially with the curves of the profile of the bone seen in the clipping direction z.

For each branch 4 of the guide 1, an inner end 20, 21 belonging to the inner surface 10 and an outer end 22, 23 not belonging to the inner surface 10 is determined, the outer end 22, 23 having a shape to substantially conform to at least one predetermined line of the outer surface S of the bone C in contact with which the guide 1 is pre-positioned before clipping, substantially in the direction of clipping.

The guide 1 is thus determined, for example using a three-dimensional printer (3D).

The manufacturing method may further comprise the complementary step of producing the guide 1 with at least two oriented drilling guns, in particular in the clipping direction, so as to allow the subsequent obtaining of the predetermined center of rotation 0 as well as the planned positioning of the prosthesis in the bone.

The advantage of the guide 1 is to allow the success of the operation, and in particular to obtain the predetermined center of rotation 0 and the planned positioning of the prosthesis in the bone, such that said positioning is linked to an orthonormal coordinate system. also predetermined and associated with the center of rotation 0.

As already explained, the fixed position of this center of rotation and the orthonormal reference that accompanies it are essential for the proper functioning of the subsequent articulation and therefore the success of the operation of the joint.

Figures 28 to 31 illustrate a first method of using the guide 1 according to the invention. This is a method of preparing the femur of a patient prior to receiving a prosthetic implant, the method comprising the steps described hereinafter.

As illustrated in FIG. 28, the guide 1 is first positioned on the neck of the femur as previously described. The guide 1 comprises two drilling guns 35.

Reference pins 50 are fixed in each of the piercing barrels 35, preferably crossing the entire femoral neck. Once the reference pins 50 fixed in the bone, the guide 1 is removed while leaving the pins 50 in place.

As illustrated in FIG. 29, a bore E, in particular a hollow bore, is made with a bore E in the neck of the femur around one of the reference pins 50 in the neck of the femur. The hollow reamer N itself has a bore of a diameter substantially equal to the diameter of the pin 50 to be guided around one of the reference pins 50. Said reference pin 50 remains inside said hollow reamer N and is extracted during the femoral neck boring operation as shown in FIG.

The reference pin 50, as shown in FIG. 30, is removed using the N reamer during the femoral neck boring operation.

Positioned in the bore E thus formed, as illustrated in FIG. 30, and resting on the other of the reference pins 50 which remains positioned in the bone C, a section guide R. As shown in FIG. 31, a (first) cut of the femoral neck C along the cutting guide R, having a cutting surface W, is produced.

Then remove the cutting guide R or first cut guide.

It should be noted that the cutting surface W and the bore E made become reference surfaces belonging to the bone to position other instruments and / or guides and / or implants, accurately, stable and unique in order to to continue the operation.

The method may then comprise a step of preparing the interior of the bone, in particular the interior of the thighbone still present under the cutting surface W and / or the metaphysis and / or the femoral shaft, for example using a multifunction guide comprising a template or preparation template, which may consist of a template or drilling template.

The method may further comprise a second cut femoral neck and / or metaphysis step according to the desired shape for implant placement, for example using a multifunction guide comprising a cutting guide.

The multifunctional guide that can be used and its method of use are illustrated in FIGS. 32 to 41.

The multifunctional guide 59, visible singly in FIGS. 36 to 39, comprises a drilling and / or preparation jig 60 made of metallic material, a custom-made abutment 61, for example made of a medical grade polymer resin material and a cutting guide. (or second cut guide) 63, made of metallic material. The multifunctional guide 59 may be made entirely of a single piece to measure, in a non-illustrated embodiment and in any suitable material, the embodiment and / or the choice of material to limit the risk of wear of said guide multifunction during the drilling and / or cutting operation.

The piercing and / or preparation template 60 makes it possible, for example, to prepare the inside of the femur for receiving one or more anchoring points of the prosthesis in the thighbone and / or the metaphysis and / or the femoral shaft, or even one or more screws for fixing the prosthesis to the bone. Orifices 62 made in the drilling template and / or preparation 60 allow for example to prepare the inside of the bone for the placement of the prosthesis. The purpose of the custom stop 61 is to assemble between them the cutting guide 63 and the drilling and / or preparation template 60. By coming into contact with the bone in the clipping direction, the custom stop 61 plays a blocking function in translation of the cutting guide 63 and / or the drilling and / or preparation template 60 on the Z axis in the clipping direction so as to accurately center the drilling and / or preparation template 60 by relative to the longitudinal axis X of the bone and the cutting guide 63 relative to the cutting surface W of the femoral neck. The custom stop 61 also allows two possibilities of assembling the drilling and / or preparation template 60 and the cutting guide 63 according to an anterior route, as illustrated in FIG. 34 and also 36 and 37, or in a posterior route. , as illustrated in FIGS. 35, 38 and 39. Several stop positions 61 can be created provided that these positions are not in interference with the resection area defined by the cutting guide 63. By reversing the direction of the gauge of drilling and / or preparation 60, the same custom stop 61 also allows to assemble different sizes of templates or drilling templates and / or preparation 60 on the same cutting guide. It is thus possible to have a single cutting guide 63 for the whole of a range of prostheses and regardless of the chosen approach (anterior or posterior or other). The advantage of this modularity is to significantly reduce the number of elements needed in the instrumentation kit to cover a full range of implants during the operation.

With reference to FIG. 32, the multifunctional guide 59 is positioned on the cutting surface W with the aid of the bore E in the bone, so as to position the drilling template 60 centered on the cutting surface W. thanks to the custom stop 61 which comes into contact with the bone in the clipping direction. The interior of the femur is then prepared using the piercing and / or preparation template 60.

The cutting guide 63 makes it possible, for its part, to cut as accurately as possible directly in connection with the preparation of the inside of the femur made with the piercing and / or preparation template 60. This preparation and this cut made by the same multifunctional guide to ensure both a precise positioning of the prosthesis in the bone at the same time that a precise support of a surface of the prosthesis on the cutting surface of the bone. This precision Laying the prosthesis both according to the preparation of the inside of the bone and resting on the cutting surface would be a real challenge if the preparation and cutting were performed with separate instruments.

When the multifunctional guide is used with a custom stop which comes into contact with the bone in the clipping direction, this last step illustrated in FIG. 40 implicitly makes it possible to fix a reference on the positioning axis of the prosthesis. which amounts to precisely controlling the center of rotation of the joint, in particular the femur, which will be possible after the placement of the prosthesis in the bone and possibly the use of a modular spherical articular head coming to connect to the end of the neck of the femoral implant.

It should be noted that the method of use of the guide 1 combined with the use of a multifunctional guide 59 with tailor-made abutment 61 allows the precise positioning of femoral hip prostheses, cemented or without cement, for the femoral prosthesis without a metaphyseal body and / or without an intramedullary stem, the positioning of which is independent of the narrow medullary canal and / or the metaphysis geometry, when the objective is to accurately prepare the interior of the femoral neck and / or the metaphysis along with the neck and / or metaphysis cut so as to accurately control the positioning and anchoring of the prosthesis in the bone while accurately controlling the support of a surface of the prosthesis on the cut of the neck and / or the metaphysis and / or if necessary by controlling the center of femoral rotation.

According to another method, the steps of which are illustrated in FIGS. 41 to 45, a re-surfacing of the head of the femur G of a patient can be carried out before receiving a resurfacing femoral prosthetic implant.

This method comprises the step of positioning the guide 1, as illustrated in FIG. 41. This guide 1 comprises or makes it possible to receive a drilling gun positioned on the top of the femur head. Indeed, as shown in FIGS. 41 to 44, the guide 1 comprises or is connected to a piercing guide 70 with a piercing gun 72 at the proximal end of the piercing guide 70. Thanks to the piercing guide 70, can fix a pin 71 in the femoral head as shown in Figures 43 to 45.

In a non-illustrated embodiment, the piercing guide 70 is connectable to the guide 1. The pin 71 is left in the femoral head G after having disconnected the piercing guide 70 from the guide 1 and then having extracted the guide 1 from the femoral neck C.

In the embodiment illustrated in FIGS. 41 to 45, the drilling guide 70 is integrated in the guide 1. In this case, the metal drilling barrel 72, visible in FIGS. 43 and 44, can be inserted into a cylinder semi open 73 visible in Figure 41 provided for this purpose at the proximal end of the piercing guide 70. The purpose of this metal barrel 72 is to avoid the release of polymer wear particles during drilling. The piercing barrel 72 can be disassembled as shown in FIG. 44 after inserting the spindle 71 into the femur head G. The opening left by the semi-open cylinder 73 of the piercing guide 70 then allows the extraction of the guide 1 while leaving the pin 71 in place in the head of femur G, as shown in Figure 45.

This second use of the guide 1 according to the invention, illustrated in FIGS. 41 to 45, allows the precise positioning of femoral hip prostheses, cemented or without cement, for the implantation of femoral re-surfacing prostheses whose positioning is independent of the narrow medullary canal and / or the geometry of the metaphysis, when the objective is to control the positioning of the prosthesis and / or if necessary the center of femoral rotation. Another example of use of the guide 1 according to the invention and illustrated in FIGS. 46 to 49.

The first steps illustrated in FIGS. 46 and 47 for laying the guide 1 and then the reference pins 50 with the aid of the drilling guns 35 made in the guide 1 and the extraction of the guide 1 are the same as in the first mode. of use of the guide 1.

However, in this example, the reference pins 50 are used directly for positioning a standard metallic Q-section guide for the resection of the neck and / or part of the metaphysis, for different approaches.

In this example, the anterior path has been illustrated.

The laying of the cutting guide Q. is illustrated in FIG. 48 while the section is made and visible in FIG. 49 leaving a cutting surface W.

This third example of use of the guide 1 combined with the use of a Q. standard metal cutting guide allows the precise positioning of femoral hip prostheses, cemented or cementless, for the fitting of prostheses with or without modularity to intramedullary stem and metaphyseal body when the objective is only to control the height of leg . The precise preparation of the resection of the femoral neck and / or the proximal part of the metaphysis (height and angle of cut) will allow this control of the leg height.

This third example of use of the guide 1 combined with the use of a standard metal cutting guide Q also allows the precise positioning of cemented or cementless hip prostheses for prostheses with or without intra-rod modularity. medullary and metaphyseal body when the positioning of the prosthesis is known in advance for accurate preparation of resection of the femoral neck and / or the proximal part of the metaphysis. For example, the numerical computation simulation can make it possible to know in advance the positioning of the prosthesis for a given femoral preparation during the preoperative planning phase. In this case, the use of the guide 1 will not only allow optimal femoral preparation (cutting) and thus the control of the leg height but also the control of the position of the femoral center of rotation.

Finally, this third example of use of the guide 1 combined with the use of a standard metallic Q-guide allows the precise positioning of femoral hip prostheses, cemented or cementless, for the fitting of femoral prostheses with or without modularity whose positioning depends on the medullary canal and / or the geometry of the metaphysis, but for a custom-made prosthesis, this positioning is known in advance. In this case, the use of the guide 1 will not only allow optimal femoral preparation (cutting) and thus the control of the leg height but also the control of the position of the femoral center of rotation.

Claims

1. Device characterized in that it comprises a first guide

(1) three-dimensional intended to be positioned by clipping on a bone (C) of a joint to restore a patient and in that it comprises a second guide called "multifunction" (59),

wherein the first guide (1) comprises a substantially U-shaped body (2) having a central portion (3) and two flexible legs (4) extending on either side of the central portion (3). , configured to allow clipping of the first guide (1) around a first portion of a bone in a predetermined clipping direction ( ^z ) and a first contact surface (10),

wherein the first guide (1) comprises two drilling barrels (35) oriented parallel to the clipping direction (z), wherein the second guide comprises a cutting guide (63), a drilling template (60) and a custom stop (61),

wherein the two piercing barrels comprise a first revolution drill barrel about a first axis and a second revolution drill barrel about a second axis, the first axis and the second axis being contained in a first plane,

wherein the cutting guide (63) comprises a peg (110) of revolution about a third axis, and wherein the drilling template (60) comprises a face (120) extending in a second plane, and in the surface of the custom stop (61) corresponds to a part of the first contact surface, in translation in the direction of the third axis, or for a first relative position of the first guide and the second guide in which the third axis is coincident with the first axis and in which the first plane would be parallel to the second plane, ie for a second relative position of the first guide and the second guide in which the third axis coincides with the second axis and in which the first plane is parallel to the second plan.

2. Device according to claim 1 wherein the first guide (1) is at least partially made to measure using medical imaging in three dimensions (3D) at least of the joint, the first guide being configured to substantially marry a second predetermined portion of the first contact surface against which it comes into initial contact before clipping in a pre-positioning, substantially in the clipping direction.

3. Device according to claim 2, wherein the outer end (22, 23) of each leg (4) is shaped to conform substantially to a surface portion of the outer surface (S) of the bone in contact with which the first guide (1) is pre-positioned before clipping substantially in the direction of clipping.

4. Device according to claim 2 or 3, wherein the shape of the outer end (22, 23) of each leg (4) is substantially identical to the shape of a line or surface portion of the inner surface (10). ) of the body (2) of the first guide (1) taken from the outer end (22; 23) and going in the reverse direction to the clipping direction.

5. Device according to any one of claims 2 to 4, wherein the inner surface (10) of the body (2) of the first guide (1) comprises two demarcation lines (13, 14) coinciding substantially with the curves of a profile of the bone seen in the clipping direction, and wherein the clipping interference of the first guide (1) is equal, for each branch (4), to a distance Ai> 0 between the projection by translation of the inner end (20, 21) of the branch (4) on a plane normal to the direction of clipping and the projection by translation on said plane of the demarcation line (13, 14) of the branch (4).

6. Device according to the preceding claim, wherein the minimum pre-positioning interference of the first guide (1) is equal, for each branch (4), to the distance between the translation projection of the outer end of the branch (4) on a plane normal to the direction clipping and projection by translation on said plane of the demarcation line of the branch (4), the minimum pre-positioning interference of the first guide being between 0 and Ai, in particular between Δί / 4 and Ai, or between Δί / 2 and Ai.

7. Device according to any one of the preceding claims, wherein the distance d3, measured in the clipping direction over the entire height of the first guide and the bone portion around which is clipped the first guide, between the outer end. (22, 23) of each branch and the line or surface portion of the outer surface (S) of the bone located first in the direction of clipping for said branch (4) is greater than an Ad value at the maximum distance between:

the distance d1 measured in the direction of clipping between, on the one hand, the inner end (20) of a first of the two branches (4) of the first guide body and, on the other hand, the corresponding line or surface portion of the outer surface (S) of the bone located first in the clipping direction, and

the distance d2 measured according to the direction of clipping between, on the one hand, the inner end (21) of the second of the two branches (4) and, on the other hand, the corresponding line or surface portion of the outer surface (S); bone located first in the clipping direction,

or d3 = max [Ad + max (dl, d2)] evaluated on the height of the first guide and the portion of the bone receiving the first guide in the clipped position around the bone, with Ad> 0.

8. Device according to any one of the preceding claims, used for an operation of the femur, having a height such that it can substantially cover the surface of the neck of the femur from the base of the neck above the metaphysis to the collar end below the head femoral out of cartilage area.

9. Device according to any one of the preceding claims, comprising a visual and / or mechanical polarizer (30) configured to prevent the practitioner from positioning the first guide (1) upside down on the bone.

10. Device according to any one of the preceding claims, the body (2) of the first guide (1) having at least one slot (40) located near an upper edge (6) or lower (5) of the first guide (1).

11. Device according to any one of the preceding claims, wherein at least one of said branches (4) comprises at least one slot (45) opening at the inner and outer end of said branch (4).

12. Device according to claim 5, the first guide (1) having a release notch (33) along one or each demarcation line (13, 14).

13. Device according to any one of the preceding claims, comprising an extraction system (68) configured to allow extraction of the first guide (1) out of the bone, in particular a threaded hole on the first guide (1). configured to allow the screwing of a metal extraction rod.

14. Device according to any one of the preceding claims, comprising a piercing guide (70) or means for connection to a piercing guide.