阅读说明：本技术 用于制作定制植入物的方法 (Method for making a customized implant ) 是由 金-皮埃尔·盖蒙 文森特·纽坦斯 于 2018-12-05 设计创作，主要内容包括：本发明涉及一种用于制作定制植入物的方法,所述定制植入物旨在植入在受损的骨骼部分的植入部位处,所述方法包括以下步骤,其中通过将标准植入物定位于受损的骨骼部分的植入部位上来将所述标准植入物的3D表示叠加在所述受损的骨骼部分的3D表示上,以便如果必要的话修改所述标准植入物的尺寸和/或调整其形状,并且如果必要的话还修改所述标准植入物的外表面,当所述受损的骨骼部分的几何形状旨在被保留时,在叠加所述植入物之前的状态下,所述外表面可以是所述骨骼部分的所述外表面的印模或基本上印模,或者当所述定制植入物旨在在彼此配合的两个骨骼部分的接口处使用时,所述外表面可以是功能外表面。(The invention relates to a method for making a customized implant intended to be implanted at the implantation site of a damaged bone part, comprising the steps of superimposing a 3D representation of a standard implant on a 3D representation of a damaged bone part by positioning the standard implant on the implantation site of the damaged bone part in order to modify the size and/or shape of the standard implant if necessary and also to modify the outer surface of the standard implant if necessary, which in the state before superimposing the implant can be an impression or a substantial impression of the outer surface of the bone part when the geometry of the damaged bone part is intended to be preserved, or when the customized implant is intended to be used at the interface of two bone parts fitting into each other, the outer surface may be a functional outer surface.)

1. A method for making a customized implant intended to be implanted on a placement site of at least one damaged bone part, characterized in that it comprises the steps of:

i. acquiring one or more images of at least said damaged bone portion;

a graphical 3D representation of the image acquired at step i of at least the damaged bone portion;

iii.a) superimposing a 3D representation of a standard implant on the 3D representation obtained at step ii by positioning the standard implant on a placement site at the surface of the at least one damaged bone part, then modifying the size and/or adjusting the shape of the standard implant, if necessary, taking into account at least one parameter of the at least one damaged bone part, then optionally modifying the outer surface of the standard implant, modifying the outer surface of the standard implant such that the standard implant thus positioned on the placement site is endowed with the following outer surfaces:

An impression or substantial impression of the outer surface of the bone part, which impression or substantial impression is occupied by the standard implant in a state before superimposing the implant when the geometry of the bone part is intended to be preserved, or

A functional outer surface, which is determined in such a way that, when the customized implant is intended to be used at an interface of two bone parts cooperating with each other, a conjugate surface of another bone part cooperating at least partially with the damaged bone part is brought into contact, which ensures articulation of the bone parts,

or

b) Having performed at least one local modification directly on the placement site of said graphical 3D representation of said at least one damaged bone portion, determining the shape and dimensions of said anchoring surface of the implant according to the shape and dimensions of said at least one local modification performed on said graphical 3D representation, said anchoring surface allowing to anchor it on said damaged bone portion and then determining said outer surface of said implant;

implementing the customized implant according to the implant certainty parameters obtained at step iii.

2. The production method according to claim 1, characterized in that the superimposition of the 3D representation of a standard implant on the 3D representation obtained at step ii is performed by means of fading.

3. A method of manufacturing according to claim 1 or 2, wherein at step iii b) the outer surface of the implant is planar, circular, or is an impression or substantial impression of an area of the damaged bone portion in a state before it is removed by the at least one local modification, or when the custom implant is intended to be used at an interface of two bone portions cooperating with each other, the outer surface of the implant is a functional outer surface determined in such a way that it is at least partially in contact with a conjugated surface of another bone portion cooperating with the damaged bone portion, which ensures articulation of the bone portions.

4. A production method according to any one of claims 1 to 3, characterized in that, at step iiia), the determination of the functional surface is performed when the two bone parts are in functional position in the graphical 3D representation, the acquisition of one or more images of the two bone parts having been performed at step i).

5. Method of manufacturing according to any one of claims 1 to 4, characterized in that the implant is part of a medical device intended to be implanted.

6. Method of manufacturing according to any one of claims 1 to 5, wherein said conjugated surface corresponds to an outer surface of a further implant intended to be received at said surface of said further bone portion cooperating with said damaged bone portion.

7. The method of manufacturing of any of claims 1-6, wherein the outer surface of the implant is determined by removing material from a solid surface of the graphical representation of the implant.

8. Method of manufacturing according to claim 7, characterized in that at step iii a), the portion of the implant to be removed is determined by: subtracting the unique graphical representation of the at least one bone portion to be repaired obtained at step ii from the graphical representation representing the combination of bone portions and standard implants positioned on the site of placement thereof.

9. The method of manufacturing of any one of claims 1 to 6, wherein the outer surface of the implant is determined by adding material.

10. A method of manufacturing according to any one of claims 1 to 9, wherein at step iii b) the local modification is a continuous recess.

11. A method of making as claimed in any one of claims 1 to 10 wherein at step iv) the implant is formed by additive manufacturing.

12. A method of manufacturing as claimed in any one of claims 1 to 11, comprising a supplementary step of additive manufacturing of the at least one bone part obtained at step ii.

13. A computer program having instructions for carrying out the method for making a customized implant according to any one of claims 1 to 12 when the program is executed by a processor.

14. A recording medium on which the computer program according to claim 13 is stored.

Technical Field

The present invention relates to a method for fabricating a customized implant, a computer program having instructions for executing the method for fabricating the customized implant, a recording medium storing the computer program, a recording medium having the computer program stored thereon, and an apparatus for fabricating a customized implant.

Background

The joint is mainly composed of:

cartilage, neither innervated nor vascularized, poorly resistant to wear;

-synovial tissue, which is rich in blood vessels and nourishes cartilage and lubricates joints;

ligaments, tendons and muscles, which are used to support the joints.

Osteoarticular diseases account for about 10% of all pathologies identified in france each year [ statement of health and economic information (Bulletin) 111 th stage (2006) ]. These inflammatory and degenerative diseases of the joints are mostly the result of aging or trauma. The disease gradually causes cartilage wear, which leads to severe physical damage. At present, there is practically no treatment available for repairing cartilage tissue, except for the implantation of joint implants for restoring the mobility of joints (arthroplasty), joint fusion for fixing joints, and osteotomy for adjusting the orientation of the mechanical axis.

For example, one of these pathologies is osteoarthritis, the most common joint disease. Osteoarthritis is a public health problem in which prevalence steadily increases: 15% in 1990 to 18% predicted in 2020.

Osteoarthritis causes significant functional limitations and a reduction in quality of life, and produces significant psychological effects. In osteoarthritis, there is not only cartilage degradation, but also degradation of all joint components (bone, synovial tissue, tendons and muscles).

The knees, hips and lumbar spine are affected first by this degenerative process because these are the joint areas most susceptible to weight and overweight. The fingers, cervical spine and shoulders also undergo this degenerative process, which is associated with repetitive hypermobility of the joints. However, this pathology may affect any joint. Mention may also be made of degradation processes which affect the movement system.

Other pathologies such as arthritis, rheumatoid arthritis, lumbago, osteoporosis and musculoskeletal disorders may be mentioned.

One of the treatments for these joint pathologies is the replacement of damaged joint surfaces with implants. According to the current technique, the implants used in this case require a considerable resection of the articular surface, which resection results in the formation of a planar surface, or several planar surfaces angled with respect to each other, at the end of the relevant bone and constituting an approximation of the actual articular surface.

This type of prosthetic element requires extensive resection of the bone in order to install it in place. This resection, in turn, requires the use of complex surgical equipment in order to precisely define the plane or planes of the resection surface to be formed. In addition, since the resection surface is planar or is made up of several planar portions, it is necessary to provide a very firm and deep anchoring of the prosthetic element in the bone portion associated with the articular surface, in order to ensure a rigid attachment of the prosthesis. However, anchoring elements such as screws, pins, studs, etc. require drilling of a large number of anchoring holes in the bone to be treated. This large number of holes or punctures in turn requires the use of special tools. Furthermore, the extent of drilling or piercing of the bone may lead to damaging consequences for the bone parts that have undergone this perforation, in particular with respect to the mechanical strength of the bone when stresses are applied to the bone constituting this joint during movement, since the anchoring element transmits the stresses, in view of its length, to the regions of the bone that are not designed to support such stresses.

Furthermore, in the case of extensive and substantially planar resections, the support of the prosthesis on the resected surface is unsatisfactory, since this surface essentially consists of cancellous bone, the support on the cortical periphery of the bone being insufficient in terms of transmitting forces.

Finally, known implants, which are standardized, do not allow the practitioner to choose from a sufficient range to meet the chosen joint degrees of freedom.

Therefore, there is a need for an implant making method that enables to obtain a customized implant, a complex shape that respects the anatomy of each individual and the joint, and thus allows the implant to adapt to the morphology and/or pathology of the individual.

Disclosure of Invention

The present invention aims to remedy the drawbacks of the prior art and to overcome the above-mentioned limitations by proposing a method for making a customized implant.

In practice, the invention relates to a method for making a customized implant intended to be implanted on a placement site of a damaged bone part, comprising the steps of superimposing a 3D representation of a standard implant on a 3D representation of a damaged bone part on a discoloration basis by positioning the standard implant on a placement site of a damaged bone part, in order to modify the size and/or shape of the standard implant if necessary, and optionally also to modify the outer surface of the standard implant, which may be an impression or a substantial impression of the outer surface of the bone part in a state before superimposing the implant, when the geometry of the damaged bone part is intended to be preserved, or when the customized implant is intended to be used at the interface of two bone parts fitting into each other, the outer surface may be a functional outer surface.

The invention also relates to a method for making a customized implant intended to be implanted on a placement site of a damaged bone portion, said method comprising a step according to which a local modification has been performed directly on the placement site of a graphical 3D representation of said damaged bone portion, the shape and size of the anchoring surface of the implant being dependent on the shape and size of said at least one local modification, so as to allow said implant to be anchored on said bone portion to be treated, followed by determining the outer surface.

Thus, and advantageously, the anchoring surface of the customized implant obtained by the method according to the invention is not planar and conforms to the placement site at the surface of the damaged bone portion by: modifying the size and/or adjusting the shape of a standard implant, or determining the shape and size of the anchoring surface relative to the at least one locally modified shape and size performed on the graphical representation of the damaged bone portion, taking into account at least one parameter of the damaged bone portion.

Thus, damaged bone surfaces are advantageously preserved. The method according to the invention makes it possible to avoid extensive and unnecessary bone resections and to determine only the necessary resections, contrary to the previous techniques, which are usually cut by sawing, according to which the anchoring of the implant is of the plane-to-plane type.

We note that it is clear from the subject of the present invention that the determination of the customized implant is obtained from one or more images acquired during the preliminary step (step i) and that no action is performed on the patient's body at any time.

The anchoring surface of the custom implant made by the method according to the invention thus replaces the recessed bone structure precisely, ensuring a healthy distribution of stresses and a major fixation of the implant without micromotion and thus a permanent fixation and bone reconstruction.

It is also advantageous that the method according to the invention enables the determination of the outer surface of a customized implant, which is an impression or basic impression of the outer surface of a damaged bone part when the geometry of said bone part is intended to be preserved, or a functional surface when said customized implant is intended to be used at the interface of two bone parts fitting into each other.

Thus, and in one case, the method for making a customized implant allows to reconstruct the outer surface of a damaged bone portion, and in another case, the outer surface is a functional surface determined according to the conjugated surface of another bone portion, with which said bone portion to be repaired cooperates in order to restore mobility of the joint in the context of arthroplasty, or to immobilize the joint in the context of arthrodesis, or to reorient the mechanical axis in the context of osteotomy, in order to obtain a customized implant which allows pathological anatomical correction and adapts to the physical and mechanical properties of the bone surface.

Thus, the method according to the invention provides a choice of customized implants responsive to joint freedom and adapted to each morphology and pathology.

The method according to the invention also saves time in the operating room, reduces costs and also saves bone.

The invention therefore relates to a method for making a customized implant intended to be implanted on a placement site of a damaged bone part, characterized in that it comprises the following steps:

i. acquiring one or more images of at least said damaged bone portion;

a graphical 3D representation of the image acquired at step i of at least the damaged bone portion;

iii.a) superimposing a 3D representation of a standard implant on the 3D representation obtained at step ii on a discolouration basis by positioning the standard implant on a placement site at the surface of the damaged bone part, then, taking into account at least one parameter of the damaged bone part, modifying the size and/or adjusting the shape of the standard implant if necessary, then optionally modifying the outer surface of the standard implant such that the standard implant thus positioned on the placement site is given the following outer surfaces:

-an impression or substantial impression of the outer surface of the bone part, which impression or substantial impression is occupied by the standard implant in a state before superimposing the implant when the geometry of the bone part is intended to be preserved, or

A functional outer surface, which, when the customized implant is intended to be used at an interface of two bone parts cooperating with each other, is determined in such a way that a conjugate surface of another bone part cooperating at least partially with the damaged bone part is in contact, which ensures articulation of the bone parts,

or

b) Having performed at least one local modification directly on the placement site of a graphical 3D representation of said damaged bone portion, determining the shape and dimensions of said anchoring surface of the implant according to the shape and dimensions of said at least one local modification performed on said graphical 3D representation, said anchoring surface allowing its anchoring on said damaged bone portion to be treated, then determining said outer surface of said implant;

implementing the customized implant according to the implant certainty parameters obtained at step iii.

Within the context of the present invention, "placement site" is understood to mean at least one region of a bone portion which is to be removed to accommodate an implant.

The placement site may be local or over the entire surface of the bone portion. The placement site may be a single chamber, a dual chamber, or a triple chamber. Thus, the placement site corresponds to a possible configuration of bone surface restoration.

Typically, bone recovery may range from 10% to 100% bone recovery.

Typically, bone restoration can be complete (100% bone restoration) and the entire bone portion can be restored.

Thus, the customized implant may be a single-compartment, dual-compartment, or triple-compartment implant.

By way of illustration only, the implant will be capable of being considered a single chamber in the context of bone restoration of up to about 30% of the bone portion, a dual chamber in the context of bone restoration between about 30% and 60% of the bone portion, and a triple chamber in the context of bone restoration between about 60% and 100% of the bone portion.

Within the context of the present invention, "bone parts" are understood to mean the ends of bones or the outer surface of bone parts.

Typically, the bone parts will be able to be selected from: bones constituting the knee joint (such as tibia and femur), lumbar vertebrae and cervical vertebrae, acromion of scapula, head of humerus, clavicle, bones constituting the foot, bones constituting the ankle, bones constituting the pelvis, bones constituting the hip, lumbar spine, cervical spine, bones constituting the shoulder, bones constituting the elbow, bones constituting the wrist, bones constituting the hand, and teeth.

In a preferred embodiment of the invention, the bone parts cooperate with each other and form a joint.

By way of illustration only, reference will be made to an intervertebral joint, a lumbosacral joint, a sacrococcygeal joint, an intercoccygeal joint, a sacroiliac joint, a pubic symphysis, a glenohumeral joint, a acromioclavicular joint, an ulnar joint, a brachioradialis joint, a proximal radioulnar joint, a radiocarpal joint, a distal radioulnar joint, an intercarpal wrist, a metacarpophalangeal joint, an interphalangeal joint, a hip joint, a patellofemoral joint, a proximal tibiofibular joint, an ankle joint, a distal tibiofibular joint, an intertarsal joint, a tarsal joint, an interplanar joint, a metatarsophalangeal joint, and an interphalangeal.

Preferably, the two parts that mate with each other will be the tibia and the femur, preferably the distal end of the femur and the proximal end of the tibia.

By "damaged bone part" is understood any bone part which is subjected to a trauma, deterioration, degeneration, inflammation, tissue destruction or degenerative process of bone tissue.

Generally, the parameters of the damaged bone parts will be able to be selected from densitometric properties (such as porosity and density), mechanical properties (such as its elastic properties and its viscoelastic properties).

The "outer surface" of the implant is understood to mean the part of the implant that is not intended to be in direct contact with the bone surface that receives the implant.

"functional outer surface" is understood to mean that part of the implant which is not intended to be in contact with the bone surface in which the implant is accommodated and which is intended to be used at the interface of two bone parts which are fitted to one another in order to generate a frictional torque.

The functional outer surface is a functional surface representing an implant surface to be mated with another functional surface of another bone portion to generate a frictional torque. Thus, a functional surface means a frictional surface that imparts functionality to a joint formed by healthy and damaged bone parts.

Typically, a joint includes one or more functional surfaces that provide individual-specific mobility and morphology. Thus, the shape and number of these surfaces vary according to the joint's ability to meet different degrees of functional mobility.

In the prior art, the implants obtained do not satisfy specific properties according to the functional surface of the implant of the joint and therefore do not satisfy specific properties of mobility and morphology of each individual. For this reason, in the case of the knee joint, the standard implant has certain troublesome consequences for the patient: tibial dislocations, tibial chamfer cuts, and changes in joint mobility and stability.

The method of the present invention makes it possible to overcome these drawbacks by providing an implant with a functional surface corresponding to that of the damaged bone portion in such a way as to preserve or restore the mobility and morphology of the individual before mounting the implant in position.

The method of the invention proposes to extract not only the anchoring surface but also the functional surface of the customized implant according to a decolourisation-based superimposition of a 3D representation of a standard implant onto an obtained 3D representation of a damaged bone part. More precisely, this extraction has been performed when the damaged bone part is in a functional position with another bone part.

In case the state of the damaged bone part does not allow to extract one or more functional surfaces of the implant, the method comprises a step in which a negative 3D image is taken from another bone part conjugated to the damaged bone part, in order to extract said one or more functional surfaces, taking into account the mobility of the individual.

The method of determining the functional surface of an implant according to the invention thus enables the friction torque between two bone parts of a joint to be reproduced and allows the following:

-preserving the integrity of the morphology;

saving friction torque, and thus saving activity

Intra-and extra-articular preservation of ligaments and menisci, allowing preservation of mobility and stability of the individual.

Within the context of the present invention, the term "anchoring surface" is understood to mean the surface of the implant intended to be in direct contact with the bone part (placement site) housing the implant.

Within the context of the present invention, the term "conjugate surface" is understood to mean a surface which may for example correspond to, but is not limited to, an outer surface of another implant corresponding to a surface of a second bone portion received at a surface of the second bone portion or cooperating with a first bone portion receiving the implant.

Thus, and according to one embodiment, a method for making a customized implant intended to be implanted on a placement site of a damaged bone part according to the present invention comprises the steps of:

i. acquiring one or more images of at least said damaged bone portion;

a graphical 3D representation of the image acquired at step i of at least the damaged bone portion;

superimposing a 3D representation of a standard implant on the 3D representation obtained at step ii on a color-fading basis by positioning the standard implant on a placement site at the surface of the damaged bone part, then, taking into account at least one parameter of said damaged bone portion, modifying, if necessary, the size and/or shape of said standard implant, then modifying an outer surface of the standard implant, the modifying of the outer surface of the standard implant such that the standard implant positioned thereby on the placement site is imparted with an outer surface, the outer surface is an impression or substantial impression of the outer surface of the bone part which, when the geometry of the bone part is intended to be preserved, in a state prior to superimposing the implant, the impression or substantially impression is occupied by the standard implant;

implementing the customized implant according to the implant certainty parameters obtained at step iii.

Superimposing a 3D representation of the implant on a 3D representation of the bone part at the surface of which the implant is intended to be accommodated and will enable dissociation of the bone part to be preserved and the bone part to be removed in order to replace it with the implant, in order to determine the limits of the implant and also the limits of the anchorage in the bone.

Advantageously, and according to one embodiment, the implant is a correct and personalized representation of the bone parts, allowing the bone surface to be reconstructed to its same state as it was in before the injury. This superposition will therefore allow a complete restoration of said bone portions with the possibility of modification, so that the customized implant thus obtained ensures an anatomical correction of the pathology.

In another embodiment, the method for making a customized implant according to the invention intended to be implanted on a placement site of a damaged bone part comprises the steps of:

i. acquiring one or more images of at least said damaged bone portion;

a graphical 3D representation of the image acquired at step i of at least the damaged bone portion;

Superimposing a 3D representation of a standard implant on the 3D representation obtained at step ii on the basis of discoloration by positioning the standard implant on a placement site at the surface of the damaged bone part, then, taking into account at least one parameter of the damaged bone part, modifying the size and/or adjusting the shape of the standard implant if necessary, and then optionally, modifying the outer surface of the standard implant, said outer surface of the standard implant being modified such that the standard implant thus positioned on the placement site is given an outer surface, said outer surface being a functional outer surface, said functional surface being determined in such a way that it is at least partially in contact with a conjugate surface of another bone part cooperating with the damaged bone part when the custom implant is intended to be used at the interface of the two bone parts cooperating with each other, this ensures articulation of the bone parts;

implementing the customized implant according to the implant certainty parameters obtained at step iii.

Superimposing a 3D representation of the implant on a 3D representation of the bone part at the surface of which the implant is intended to be accommodated and will enable dissociation of the bone part to be preserved and the bone part to be removed in order to replace it with the implant, in order to determine the limits of the implant and also the limits of the anchorage in the bone.

Again advantageously, said outer surface will be additionally reworked in such a way as to reestablish the complementarity of the joint, in order to obtain a functional bone surface.

Typically, the implant will be a standard implant, an implant blank, or a new avatar corresponding to the new standard.

Typically, the implant will be able to be selected from a standard library of 3D implant representations, adapted to the patient's morphology and the degree of repair to be performed.

The implant will be able to assume geometric shapes (cylindrical, parallelepiped, cuboid, etc.) or any random and non-geometric shape. Alternatively, the implant may be made freehand.

In yet another embodiment, the method for making a customized implant according to the invention intended to be implanted on a placement site of a damaged bone part comprises the steps of:

i. acquiring one or more images of at least said damaged bone portion;

a graphical 3D representation of the image acquired at step i of at least the damaged bone portion;

having performed at least one local modification directly on the placement site of the graphical 3D representation of the bone portion to be treated, determining the shape and size of the anchoring surface of the implant according to the shape and size of the at least one local modification performed on the graphical 3D representation, said anchoring surface allowing to anchor it on the damaged bone portion and then determining the outer surface of the implant;

implementing the customized implant according to the implant certainty parameters obtained at step iii.

Advantageously, and in this embodiment, the shape and size of the anchoring surface of the implant are determined according to the shape and size of at least one local modification made directly on the graphical representation of the bone portion intended to receive the implant.

In practice, according to the realisation of at least one local modification on a graphical representation of said bone portion intended to receive the implant, the shape and dimensions of the implant will be determined in such a way that the anchoring surface of said implant is a locally modified impression or basic impression projected onto said bone portion.

The complementarity of the anchoring zone of the implant with the local modification of the bone portions makes it possible to limit the bone resection and therefore preserve the anatomical structure.

Advantageously, the shape and dimensions of the anchoring surface of the implant correspond exactly to the shape and dimensions of said at least one local modification made on the bone portion. Thus, the locally modified periphery corresponds to the periphery of the anchoring surface of the implant.

The quality of the image obtained will determine the quality of the customized implant and its accuracy. The method according to the invention comprises the step of acquiring one or more images by Computed Tomography (CT) and/or Magnetic Resonance Imaging (MRI) of at least one bone part, or any other method of acquiring one or more images.

Computed tomography has better spatial resolution and image acquisition of bone parts is more accurate. In a preferred embodiment, Magnetic Resonance Imaging (MRI) will be used to accurately visualize cartilage. In another embodiment, the image acquisition is achieved by a combination of computed tomography and magnetic resonance imaging, or by any other method that allows the acquisition of an image or 3D representation.

Advantageously, the production method according to the invention enables the production of a customized implant according to the modifications and/or interventions to be made on at least one bone part of a patient, and thus adapted and customized to each patient.

In practice, the acquisition step produces a layer-by-layer representation of the state and the exact form of the at least one bone part. The acquired 2D image will then be converted into 3D at step ii. This produces a 3D volume file that is an exact and unique representation of the patient's morphology and in particular the damaged bone parts.

The image thus acquired will then be 3D modeled on a computer.

By way of illustration only, the 3D support format would be STEP, IGES, NURBS, etc. And completing the transmission of the image through coding. For example, we mention the DICOM file from SCAN.

The image will be converted into a 3D CAD file.

In various specific embodiments of the implant fabrication method, each specific embodiment has its specific advantages and many possible technical combinations are possible:

-superimposing a 3D representation of a standard implant onto the 3D representation obtained at step ii is performed by fading.

-at step iii b), the outer surface of the implant is planar and rounded, or is an impression or substantial impression of an area of the bone portion to be treated in a state before its removal by the at least one local modification, or again, when the customized implant is intended to be used at the interface of two bone portions cooperating with each other, the outer surface of the implant is a functional outer surface determined in such a way that a conjugate surface of another bone portion cooperating at least partially with the damaged bone portion is in contact, which ensures articulation of the bone portions.

Advantageously, this embodiment enables reworking of the complementarity of the joint.

-at step iii a), determining that the functional surface is performed when the two bone parts are in functional positions in the graphical 3D representation, one or more images of the two bone parts having been acquired at step i).

The term "functional position" is understood as a position in which the two bone parts are not dislocated or displaced from their functional base. Thus, depending on the morphology of the patient and its mobility, the functional position corresponds to the ideal functional position of the patient.

The extracted functional surface enables the production of customized implants that can reproduce different degrees of mobility specific to the individual of the joint in question. The specificity of this functional activity is not reproduced in standard implants.

The implant is part of a medical device intended to be implanted.

In a preferred embodiment, said conjugate surface corresponds to an outer surface of a further implant, which outer surface is intended to be received at said surface of said further bone portion cooperating with said damaged bone portion.

-the outer surface of the implant is determined by removing material from a solid surface of the graphical representation of the implant.

-at step iii a), determining the portion of the implant to be removed by: subtracting the unique graphical representation of the at least one damaged bone portion obtained at step ii from the graphical representation representing the assembly of bone portions and the standard implant positioned on its placement site.

-the outer surface of the implant is determined by adding material.

Typically, and at step iii b), the local modification will be able to be selected from arthroplasty, osteotomy or arthrodesis.

Arthrodesis is understood as an intervention intended to immobilize a joint by bone fusion and to prevent it by bone suturing.

Arthroplasty is a surgical intervention used to restore mobility to a joint by creating a new joint space.

An osteotomy is understood as a surgical procedure consisting of: the diaphysis of the long bone is cut in order to better reorient the axis or axes of the bone and thus better reposition the joints above and below.

In a preferred embodiment, the local modification is arthroplasty, preferably the local modification is the formation of a continuous recess on at least a portion of the bone surface.

-at step iv), the implant is made by additive manufacturing.

Additive manufacturing is selected from the following techniques: stereolithography, Selective Laser Sintering (SLS), Fused Deposition Modeling (FDM), Selective Laser Melting (SLM), or any method of additive manufacturing, such as Electron Beam Melting (EBM).

The manufacturing will also be able to be performed by conventional tools, e.g. 5-axis machining.

In a preferred embodiment, the implant is made of a biocompatible material.

A biocompatible material is understood to be any material having the ability not to interfere with and degrade the biological environment in which it is used.

Examples which may be mentioned, by way of illustration only, are metals and metal alloys (such as stainless steel, in particular 316L stainless steel or 17-4PH stainless steel), titanium and titanium alloys (such as grade 1, grade 2, grade 4, grade 5, grade 23 titanium), chromium cobalt, ceramics (such as alumina and zirconia). Mention will also be made of polyethylene or ultra-high density polyethylene, polyamide 12(PA12) and Polyetheretherketone (PEEK).

Preferably, the material will be selected from alumina ceramics, chromium cobalt, polyetheretherketone.

In another embodiment, the implant will be made of a biocompatible and resorbable material.

By way of illustration only, the material will be selected from magnesium, resorbable polymers such as Polylactide (PLA), Polyglycolide (PGA), Polyhydroxybutyrate (PHB) or Polyhydroxyvalerate (PHV), but most commonly suitable copolymers such as polylactide (L-D/L).

-the method comprises a supplementary step of additive manufacturing of the at least one bone part obtained at step ii.

The additive manufacturing of the at least one bone part enables to verify the suitability of the implant made by the method according to the invention.

The invention also relates to a computer program with instructions for carrying out the method for producing a customized implant according to the invention, when said program is executed by a processor.

The invention also relates to a recording medium on which a computer program according to the invention is stored.

The invention also relates to a device for producing a customized implant, said device comprising a first image acquisition means and a second calculation means, said first image acquisition means and said second calculation means being configured to perform a method for producing a customized implant by a method according to the invention.

The apparatus further includes a three-dimensional printer configured to form a three-dimensional implant.

The first image acquisition means comprises a magnetic resonance imaging device and/or a computer tomography imaging device.

The invention also relates to a customized implant obtained by the method according to the invention.

In a preferred embodiment, the implant is intended to be anchored on at least two bone parts cooperating with each other after at least one local modification of at least one of said bone parts, preferably both bone parts.

Preferably, said at least two bone portions correspond to apposition areas defining a joint.

By way of illustration only, reference will be made to an intervertebral joint, a lumbosacral joint, a sacrococcygeal joint, an intercoccygeal joint, a sacroiliac joint, a pubic symphysis, a glenohumeral joint, a acromioclavicular joint, an ulnar joint, a brachioradialis joint, a proximal radioulnar joint, a radiocarpal joint, a distal radioulnar joint, an intercarpal wrist, a metacarpophalangeal joint, an interphalangeal joint, a hip joint, a patellofemoral joint, a proximal tibiofibular joint, an ankle joint, a distal tibiofibular joint, an intertarsal joint, a tarsal joint, an interplanar joint, a metatarsophalangeal joint, and an interphalangeal.

In a preferred embodiment, the implant is intended to be anchored at the proximal end of the tibia and the distal end of the femur of the tibiofemoral joint.

The invention also relates to an implant comprising:

-an anchoring surface, said surface being an impression or a basic impression of:

-a placement site of a damaged bone part;

-at least one local modification on a damaged bone part;

-an outer surface, the outer surface being:

-an impression or substantial impression of the outer surface of the bone part, which impression or substantial impression is occupied by the standard implant in a state before superimposing the implant when the geometry of the bone part is intended to be preserved, or

-a functional outer surface, which, when the customized implant is intended to be used at an interface of two bone parts cooperating with each other, is determined in such a way that a conjugate surface of another bone part cooperating at least partially with the damaged bone part is in contact, which ensures articulation of the bone parts;

-at least one anchoring device intended to cooperate with at least one anchoring zone on at least one part of a bone portion.

In one embodiment of the invention, the anchoring means is a bump.

In another embodiment, the portion providing the anchoring may be a hook.

The anchoring surface of the implant according to the invention comprises surface undulations for enhancing the anchoring of the implant on the bone surface.

Typically, and by way of illustration only, this surface relief is formed by bulges and/or hollows and/or trabeculae.

For example, the protrusions are ribs or spikes, and the hollows are tubes formed within the thickness of the inner surface of the implant.

The bulges and/or hollows may be aligned by being regularly or irregularly spaced apart from each other so as to define radially or substantially radially radiating lines or branches.

Thus, and advantageously, the surface relief of the inner surface makes it possible to increase the anchoring of the implant on the bone surface and to promote ossification after the implant has been put in place.

-the implant is made of alumina ceramic.

In another embodiment, and by way of illustration only, the implant may be made of a biocompatible material, that is to say a material having the ability not to interfere with and degrade the biological environment in which it is used.

Examples which may be mentioned are metals and metal alloys (such as stainless steel, in particular 316L stainless steel or 17-4PH stainless steel), titanium and titanium alloys (such as grade 1, 2, 4, 5, 23 titanium), chromium cobalt, ceramics (such as alumina and zirconia), tantalum, composite alloys (such as alloys of titanium and aluminum or titanium and tantalum) and all alloys which may have additive manufacturing. Polyethylene or ultra-high density polyethylene will also be mentioned.

-said at least one local modification is an arthroplasty defining a recess intended to receive said implant, the anchoring surface of which is an impression of a bone surface region in a state before its removal by concavity.

Indeed, in a preferred embodiment, the local modification is arthroplasty and consists in resecting at least one bone surface to define a recess adapted to receive an implant according to the invention.

The implant comprises at least two tabs connected by said anchoring means.

In one embodiment, the implant or prosthesis has a shape selected from U-shape, V-shape, W-shape, X-shape and O-shape, and will be a customized implant according to the patient's pathology and/or morphology.

In a preferred embodiment, the implant according to the invention is a U-shaped implant comprising two tabs connected by anchoring means.

In another embodiment, the implant is a one-piece implant, the implant being an implant consisting of two coupled implants, the implants consisting of different implants, screws, plates, rods in combination.

The invention also relates to an implant within the meaning of the invention for the treatment of osteoarticular pathologies, such as osteoarthritis, arthritis, rheumatoid arthritis, lumbago, osteoporosis, musculoskeletal disorders, etc.

Preferably, the implant according to the invention is used for the treatment of osteoarthritis of the knee joint.

Drawings

Other advantages, objects and specific features of the invention will become apparent from the following description, given for purposes of illustration and not limitation and in which reference is made to the accompanying drawings, in which:

Fig. 1 is a perspective view of two customized implants and a tibiofemoral joint made by a method according to the present invention.

Fig. 2 is a perspective view of two customized implants made by a method according to the invention, anchored in the tibiofemoral joint.

Fig. 3 is a perspective view of two customized implants made by a method according to the present invention.

FIG. 4 is a perspective view of a standard implant selected from the library. The implant is a 60% dual chamber implant.

Fig. 5 is a perspective view of a 3D representation of a bone portion superimposed with a 3D representation of a standard implant.

Fig. 6A and 6B are perspective views of a 3D representation of a bone portion in 3D and a 3D representation of a standard implant and size modification and/or shape adjustment and outer surface modification of the 3D representation of the standard implant.

Fig. 7 is a perspective view of a 3D representation of a tibiofemoral joint and a 3D representation of a standard implant designed specifically for the damaged bone portion.

Fig. 8 is a perspective view of a 3D representation of a tibiofemoral joint and a 3D representation of an implant designed specifically for the damaged bone portion, the functional surface of the implant having been determined.

Fig. 9 is a 3D representation of a tibiofemoral joint and an implant having a geometry substantially corresponding to a local modification.

Fig. 10 is a 3D representation of the tibiofemoral joint and placement site once the shape and size of the 3D representation of the implant has been determined and the functional surface has also been determined.

Detailed Description

It should be noted at the outset that the drawings are not to scale.

An image of a bone part, here the bone part fitted in the tibiofemoral joint, has been acquired by magnetic resonance imaging and then has been segmented and 3D modeled on a computer, the image being transmitted in STL format. Thus, a 3D image of the tibiofemoral joint (i.e., of the proximal end 30 of the tibia and the distal end 20 of the femur) has been acquired and is in functional position, as shown, for example, in fig. 1.

On the basis of the 3D image of the tibiofemoral joint in functional position, the recesses required for accommodating the custom implants 11, 12 have been made in the 3D image of the tibiofemoral joint in order to locally modify the proximal tibial end 30 and the distal femoral end 20.

A recess 21 has been formed in the distal femoral end 20 and a recess 31 has been formed in the proximal tibial end 30.

By means of each recess 21, 31, the shape and size of each implant (11 and 12 respectively) will be determined in such a way that the anchoring surface 111, 121 of each implant is an impression of the removed areas 21, 31 of the distal femoral end 20 and the proximal tibial end 30.

The custom implants 11 and 12 are intended for use at the interface of two bone parts that mate with each other, the outer surface 112 of the implant 11 and the outer surface 122 of the implant 12 being functional surfaces.

Thus, the functional surface 112 of the implant 11 will be defined by the conjugate surface of the proximal tibial end 30 that the distal femoral end 20 mates with, which ensures articulation between the proximal tibial end 30 and the distal femoral end 20, the conjugate surface corresponding to the functional outer surface 122 of the implant 12.

In the same way, the functional surface 122 of the implant 12 will be defined by the conjugate surface of the distal femoral end 20 to which the proximal tibial end 30 mates, which ensures articulation between the proximal tibial end 30 and the distal femoral end 20, the conjugate surface corresponding to the functional outer surface 112 of the implant 11.

The articulation between the proximal tibial end 30 and the distal femoral end 20 is advantageously restored.

Advantageously, the method for making a customized implant according to the invention will enable the bone to be resected only to the extent required, and will preserve the patient's bone stock and reconstruct the tibiofemoral joint (fig. 2).

In an embodiment of the invention, the distal femoral end 20 and the proximal tibial end 30 have been made by additive manufacturing in order to verify the suitability of the implant.

Fig. 3 shows a customized medical device consisting of an implant 11 intended to be received on the distal end 20 of a femur (not shown) and an implant 12 intended to be received on the proximal end 30 of a tibia (not shown), both implants representing a three-compartment prosthesis obtained by the method according to the invention.

Each implant comprises an anchoring surface 111, 121, which is at least a locally modified impression or basic impression on the damaged bone parts, a functional surface 112, 122 intended to be used at the interface of the two bone parts that cooperate with each other to ensure the articulation of the tibia and the femur, and a protrusion 113, 123 connecting the two tabs of each body. The relationship of the outer surfaces 112 and 122 is the friction torque.

The anchoring surface of each implant comprises surface undulations intended to enhance the anchoring of said implant. This internal relief is constituted by trabeculae, which are porous structures that adopt a design of cancellous bone and allow particularly effective bone reconstruction.

The implants 11 and 12 are made of titanium. The trabeculae of the anchoring surfaces 111 and 121 of the implant are made by plasma spraying a titanium oxide suspension.

Advantageously, the implant according to the invention, and more specifically the total knee prosthesis according to this particular embodiment of the invention, is a customized implant, identical to the patient's morphology and fully incorporating the patient's personal functions (displacement/sliding/rotation), said customized implant being obtained by the method according to the invention.

Fig. 4 corresponds to a standard implant 40 selected from the library. The implant is a 60% dual chamber implant.

Standard implants are modeled in CAD.

Fig. 5 is a perspective view of a 3D representation of a bone portion, here the proximal tibial end 30, and a superimposed 3D representation of a standard implant 40.

According to the method for making a customized implant according to the invention intended to be implanted on a placement site of a damaged bone part, an image of the proximal end 30 of the tibia has been acquired by magnetic resonance imaging, and subsequently said image has been segmented and 3D modeled on a computer, said image being transmitted in STL format. A 3D image of the proximal tibial end 30 is thus acquired.

A 3D representation of standard implant 40 has been superimposed on a 3D representation of proximal end 30 of the tibia by positioning standard implant 40 over the placement site of the surface of damaged proximal end 30 of the tibia.

According to fig. 6, the dimensions of a standard implant 40 will be modified and the shape of said standard implant 40 will be adjusted by subtracting material from the implant.

The outer surface 41 of the standard implant will be modified in such a way that it is an impression or substantial impression of the outer surface of the bone parts, which impression or substantial impression is occupied by the standard implant in the state before the implant is superimposed, in order to preserve the geometry of the bone parts.

Thus, and advantageously, the geometry of the proximal end will be able to be reconstructed.

Fig. 7 is a perspective view of a 3D representation of a tibiofemoral joint and a 3D representation of a standard implant designed specifically for the damaged bone portion.

In the same way as before, an image of the proximal end 30 of the tibia and an image of the distal end 20 of the femur have been acquired by magnetic resonance imaging, and then the images have been segmented and 3D modeled on a computer, the images being transmitted in STL format. Thus, 3D images of the proximal end 30 of the tibia and the distal end 20 of the femur are acquired.

The 3D representation of the geometrically designed implant 50, specifically intended for the damaged bone parts (that is to say, the lateral condyle 21 distal to the femur and the lateral platform 31 proximal to the tibia), has been superimposed on the 3D representation on the placement site at the surface of each damaged bone part (that is to say, at the surface of the lateral condyle 21 distal to the femur and the lateral platform proximal to the tibia).

In this case, the 3D representation of the implant does not correspond to a standard implant, but to a 3D representation of a newly created implant, which is determined by the practitioner from a geometrical point of view to be more adapted to the damaged bone part.

The shape and size of the 3D representation of the implant will be modified so as to replace the injured bone parts at the surface of the lateral condyle at the distal femur and the lateral plateau at the proximal tibia with the 3D representation of the implant on the 3D representation, so as to determine the limits of the implant and also the limits of the anchoring of the implant in the lateral femoral condyle and the lateral tibial plateau in such a way that the implant is a correct and personalized representation of the subtracted and damaged bone parts.

The implant is intended to be used at the interface of two bone parts that mate with each other, namely the lateral condyle 21 at the distal end of the femur and the lateral platform 31 at the proximal end of the tibia.

Furthermore, once the 3D representation of the implant 50 has been positioned on the placement site of the damaged bone portion, and the size modification and shape adjustment of the implant has been performed so as to correspond to the damaged bone portion to be treated, it will be determined the outer surface of the implant anchored in the lateral condyle 21 of the distal end of the femur and the outer surface of the implant anchored on the lateral plateau of the proximal end of the tibia, said two surfaces being functional surfaces.

Thus, as shown in FIG. 8, the functional surface 51 of the 3D representation of the implant anchored on the lateral platform 31 will be determined according to the conjugate surface of the lateral condyle 21 to which the lateral platform mates, which corresponds to the functional outer surface 52 of the implant, in order to ensure articulation between the lateral platform 31 and the lateral condyle 21.

In the same way, the functional surface 52 of the 3D representation of the implant anchored on the lateral condyle 21 will be determined according to the conjugate surface of the tibial plateau 31 with which said lateral condyle cooperates, in order to ensure articulation between the lateral plateau 31 and the lateral condyle 21, the conjugate surface corresponding to the functional outer surface 51 of the implant.

The articulation between the lateral condyle 21 of the distal end of the femur and the lateral plateau 31 of the proximal end of the tibia is advantageously restored.

Fig. 9 is a 3D representation of a tibiofemoral joint and an implant having a geometry substantially corresponding to a local modification.

In the same way as before, an image of the proximal 30 of the tibia and an image of the distal femoral end 20 have been acquired by magnetic resonance imaging, and then the images have been segmented and 3D modelled transmitted on a computer, the transmission of the images being in STL format. Thus, 3D images of the proximal tibial end 30 and the distal femoral end 20 are acquired.

A 3D representation comprising a cutting axis aid 60 has been superimposed on the 3D representation on the placement site at the surface of each damaged bone portion, each cutting axis being determined by the longitudinal axis of the catheter of the tool (e.g., a drill bit defining a working area). The cutting axis of the 3D representation of this aid corresponds to the local modification of the surface of each damaged bone part.

Thus, the 3D representation of the aid 60 has eight tubular elements 61, 62, 63, 64, 65, 66, 67, 68, each having a longitudinal axis, each longitudinal axis of each of the tubular elements coinciding on the 3D representation of the tibiofemoral joint with only one of the eight working axes determined by the practitioner, corresponding to the local modification to be made to the damaged bone surface.

For example, the longitudinal axis of the tubular element 61 of the 3D representation of the aid will substantially correspond to the concavity of the inferior portion of the lateral condyle through the distal femoral end.

The longitudinal axis of the tubular element 62 of the 3D representation of the aid will substantially correspond to the concavity of the inferior portion of the medial condyle through the distal femoral end.

The longitudinal axis of the tubular element 63 of the 3D representation of the aid device will substantially correspond to the concavity directed towards the side of the pulley.

The longitudinal axis of the tubular element 64 of the 3D representation of the aid will substantially correspond to the concavity directed to the apposition area between the posterior of the lateral condyle and the lateral glenoid surface of the tibial plateau.

The longitudinal axis of the tubular element 66 of the 3D representation of the aid will substantially correspond to the concavity directed to the apposition area between the posterior of the medial condyle and the medial glenoid surface of the tibial plateau.

The longitudinal axis of the tubular element 65 of the 3D representation of the accessory device will substantially correspond to the recess pointing towards the intermediate groove (or trench) of the trolley.

The longitudinal axis of the tubular element 67 of the 3D representation of the aid device will substantially correspond to the concavity directed towards the middle cheek of the pulley.

The longitudinal axis of the tubular member 68 of the 3D representation of the aid will substantially correspond to the concavity of the anterior surface of the spine directed toward the superior surface of the proximal tibia.

Thus, as shown in fig. 10, in the case of a local modification of the 3D representation of the tibiofemoral joint, the shape and dimensions of the anchoring surface of the implant will be able to be determined according to the shape and dimensions of the local modification thus made (here the recesses 612, 622 formed on the 3D representation of the tibiofemoral joint) by: the volume of the implant 60 is subtracted so that the anchoring surface of the implant allows the implant to be anchored on the damaged bone portion.

Once the anchoring surface has been formed, the outer surface of the implant will be determined.

The functional surface of the 3D representation of the implant anchored on the distal femoral end 20 will be determined according to the conjugate surface of the proximal tibial end 30 with which it cooperates, in order to ensure articulation between the distal femoral end 20 and the proximal tibial end 30, the conjugate surface corresponding to the functional outer surface of the implant.

In the same way, the functional surface of the 3D representation of the implant anchored on the proximal tibial end 30 will be determined according to the conjugate surface of the distal femoral end 20 cooperating with said proximal tibial end, in order to ensure articulation between the distal femoral end 20 and the proximal tibial end 30, the conjugate surface corresponding to the functional outer surface of the implant.

The articulation between the distal femoral end 20 and the proximal tibial end 30 is advantageously restored by the knee resurfacing prosthesis thus obtained and is intended to replace the worn rollers of the condyles that roll, slide and rotate on the self-worn glenoid surface of the tibial plateau and to do so without affecting in any way the mechanical balance of the joint.