Anatomical knee joint prosthesis and design method thereof

Abstract

A method for producing a partial or total knee prosthesis suitable for human anatomy of an individual patient, the method comprising a design step of taking into account the patient's current and pre-lesion knee motion behavior, and further taking into account the patient's individual hip-knee-ankle joint (HKA) mechanical alignment, and utilizing these inputs, to produce a partial or total knee prosthesis suitable for human anatomy of the individual patient. A knee joint model as natural is recreated, where still the recreated natural knee joint model rather than the diseased knee joint model is used to create a prosthesis that recreates the natural knee joint.

Description

[0001] Divisional application

[0002] This invention patent application is a divisional application of a prior PCT application filed in China with patent number 202180016757.8, filed on January 22, 2021, and entitled "Anatomical Knee Prosthesis and Design Method Thereof." The international application number corresponding to the parent application is PCT / IB2021 / 050496.

[0003] CROSS-REFERENCE TO RELATED APPLICATIONS

[0004] This application claims the benefit of U.S. Provisional Patent Application No. 62 / 964,170, filed on January 22, 2020, and U.S. Provisional Patent Application No. 62 / 964,182, filed on January 22, 2020, the entire contents of which are expressly incorporated herein by reference, and relies on that application to identify features that may be sought for protection herein, as it is believed that the entire contents thereof contribute to solving the basic technical problems of the invention, and some features that may be mentioned below are particularly important.

[0005] Identity of the parties involved

[0006] The applicant in this intellectual property matter is Symbios Orthopedie SA of Switzerland. The inventors of the invention described in this patent document are Vincent LECLERCQ, a French citizen of Echandens, Switzerland, and Florent PLE, a French citizen of Preverenges, Switzerland. Additional inventors may be added when the regular application is filed. At the time of filing, the applicant was represented by John B. Moetteli and Da Vinci Partners LLC of Switzerland.

[0007] Copyright and Legal Notices

[0008] Portions of the disclosure of this patent document contain material that is subject to copyright protection. The applicant has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure, as it appears in the Patent and Trademark Office patent file or records, but otherwise reserves all copyright rights whatsoever. Furthermore, any citation herein to third-party patents or articles is not to be construed as an admission that the present invention is not entitled to antedate such material by virtue of prior invention. Background Art

[0009] Today's knee prostheses have been standardized due to optimization in industrial production. While existing prostheses offer satisfactory service life (+93% after 15 years), customer satisfaction is low (only 70%). As a result, many patients who could benefit from a prosthesis postpone surgery due to concerns about the risk of discomfort or pain, ultimately leading to worsening of their condition and the need for more dangerous treatments. Chronic discomfort and pain after knee replacement surgery is primarily due to the difference between the behavior of the standardized prosthesis and the individual's original knee anatomy, which varies from person to person.

[0010] When the first knee joint is replaced with a prosthesis and the patient does not replace the second knee joint at the same time, the use of standard knee prostheses with existing technology may result in an imbalance between the replaced knee joint and the original knee joint, causing accelerated aging and / or deformation of the unreplaced knee joint, and ultimately requiring premature replacement of the second knee joint.

[0011] Therefore, there is a need for a knee prosthesis that can replace the original knee joint in a manner that is individually adapted to the patient's anatomical behavior, thereby minimizing the risk of discomfort or pain and without collateral damage to the other knee joint. Summary of the Invention

[0012] A knee prosthesis and a method for selecting a knee prosthesis for a specific patient from a list of available knee prostheses or from a 3D knee prosthesis model are provided. The method comprises the following steps: (a) parameterizing the knee prosthesis according to well-defined and independent knee compartments, (b) generating a large number of knee shapes in the form of 3D knee prosthesis models that reproduce the asymmetry of each individual knee's 3D shape, thereby reproducing the knee motion of substantially any patient by generating shapes that vary the shape parameters (surface and dimensions) of at least one of these compartments, and storing these 3D knee prosthesis models in a database, and (c) studying the patient's pathology and establishing criteria for a pre-lesion knee prosthesis that meets the patient's needs. A suitable knee prosthesis can be selected from the list of available knee prostheses or from the large number of knee shapes, and the prosthesis or shape that best meets the patient's needs as determined by the study is selected.

[0013] In another embodiment, the method includes considering the patellar joint in selecting the appropriate 3D model.

[0014] Compared to prior art knee prostheses, the present invention provides a knee prosthesis that can be better tailored to the needs of a specific individual patient, thereby resulting in a lower risk of chronic pain and / or discomfort. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The accompanying drawings show, by way of example, different embodiments of the invention.

[0016] Figure 1A This is a three-quarter diagram of the knee joint.

[0017] Figure 1B This is a schematic medial view of the knee joint.

[0018] Figure 2A It is a front view illustrating the normal mechanical alignment of the hip-knee-ankle (HKA), which is also called the "neutral" mechanical axis or the "upright" mechanical axis.

[0019] Figure 2B This is a front view showing the mechanical alignment of HKA varus (bow legs).

[0020] Figure 2C It is a front view showing the mechanical alignment of HKA valgus (X-legs).

[0021] Figure 3 It is a flow chart of the method of the present invention.

[0022] Figure 4 is a flow chart of a first variant of the method of the present invention.

[0023] Figure 5 is a flow chart of a second variant of the method of the present invention.

[0024] Figure 6 is a flow chart of a third variant of the method of the present invention.

[0025] Figure 7A is an anterior view of the femur.

[0026] Figure 7B This is a top view of the femur.

[0027] Figure 8A This is a front view of the knee with extension.

[0028] Figure 8B This is a front view of the knee with flexion.

[0029] Figure 9A 1 is an ISO view of a femoral implant of a knee prosthesis according to the present invention.

[0030] Figure 9B FIG. 4 is a frontal view of the femoral implant of the knee joint prosthesis of the present invention.

[0031] Figure 9C FIG. 4 is a sagittal view of the femoral implant of the knee joint prosthesis of the present invention.

[0032] Figure 10A 1 is a frontal view of the knee joint prosthesis of the present invention.

[0033] Figure 10B It is a schematic diagram of the axial surface of the knee joint prosthesis of the present invention.

[0034] Figure 10C 1 is a sagittal schematic diagram of the knee joint prosthesis of the present invention.

[0035] Figure 11A is a frontal view of a prior art knee prosthesis.

[0036] Figure 11B 1 is a frontal view of the knee joint prosthesis of the present invention.

[0037] Figure 11C It is a schematic diagram of the axial surface of a knee joint prosthesis in the prior art.

[0038] Figure 11D It is a schematic diagram of the axial surface of the knee joint prosthesis of the present invention.

[0039] Figure 12A Schematic diagram of the coronal plane of the knee joint prosthesis of the present invention when the femur is in neutral position (the distal condyles are symmetrical) and in extension (the distal condyles are symmetrical).

[0040] Figure 12B The figure is a cross-sectional schematic diagram of the knee joint prosthesis with symmetrical posterior condyles of the present invention when flexed (posterior condyles are symmetrical).

[0041] Figure 12C Schematic diagram of a cross section of the knee joint prosthesis of the present invention during flexion, wherein the lateral posterior condyle is shorter than the medial posterior condyle (posterior condyle internally rotated).

[0042] Figure 12D Schematic diagram of the cross section of the knee joint prosthesis of the present invention when flexed, wherein the lateral posterior condyle is longer than the medial posterior condyle (posterior condyle is externally rotated).

[0043] Figure 12E It is a cross-sectional schematic diagram of the knee joint prosthesis of the present invention when flexed, wherein an angle is opened from the lateral posterior condyle to the medial posterior condyle (posterior condyle internal rotation).

[0044] Figure 12F It is a cross-sectional schematic diagram of the knee joint prosthesis of the present invention when flexed, wherein an angle is opened from the medial posterior condyle to the lateral posterior condyle (posterior condyle external rotation).

[0045] Figure 12G Schematic diagram of the coronal plane of the knee joint prosthesis of the present invention when the femur is in neutral position (the distal condyles are symmetrical) and in extension (the distal condyles are symmetrical).

[0046] Figure 12H 1 is a coronal schematic diagram of the knee joint prosthesis of the present invention in a femoral valgus and extension state, wherein the distal lateral condyle is shorter than the distal medial condyle.

[0047] Figure 12I1 is a coronal schematic diagram of the knee joint prosthesis of the present invention in a femoral varus and extension state, wherein the distal lateral condyle is longer than the distal medial condyle.

[0048] Figure 12J It is a coronal schematic diagram of the knee joint prosthesis of the present invention in a state of femoral valgus and extension, wherein an angle is opened from the distal lateral condyle to the distal medial condyle.

[0049] Figure 12K It is a coronal schematic diagram of the knee joint prosthesis of the present invention in a condition of femoral varus and extension, wherein an angle is opened from the distal medial condyle to the distal lateral condyle.

[0050] Figure 13A 1 is a coronal schematic diagram of the knee joint prosthesis of the present invention when extended.

[0051] Figure 13B It is a cross-sectional schematic diagram of the knee joint prosthesis of the present invention when flexed.

[0052] Figure 13C Schematic diagram of the sagittal plane of the femoral implant of the knee joint prosthesis of the present invention.

[0053] Figure 14A is a cross-sectional view in the coronal plane of the femoral implant of the present invention in extension, showing the planar resection.

[0054] Figure 14B is a cross-sectional view of a femoral implant of the present invention in cross section in flexion, showing the planar resection.

[0055] Figure 14C is a cross-sectional view in the coronal plane of the femoral implant of the present invention in extension, showing the oblique resection.

[0056] Figure 14D is a cross-sectional view of a femoral implant of the present invention in cross section in flexion, showing the oblique resection.

[0057] Figure 14E is a cross-sectional view in the coronal plane of the femoral implant of the present invention in extension, showing the curved resection.

[0058] Figure 14F is a cross-sectional view of a femoral implant of the present invention in cross section in flexion, showing the curved resection.

[0059] Figure 14G is a cross-sectional view in the coronal plane of the femoral implant of the present invention in extension, showing the offset resection.

[0060] Figure 14H is a cross-sectional view of a femoral implant of the present invention in flexion, showing the offset resection.

[0061] Figure 14Iis a cross-sectional view in the coronal plane of the femoral implant of the present invention in extension, showing the double oblique resection.

[0062] Figure 14J is a cross-sectional view of a femoral implant of the present invention in cross section in flexion, showing the double oblique resection.

[0063] Figure 14K It is a sagittal view of the femoral implant of the present invention in extension, suitable for sawing and resection.

[0064] Figure 14L It is a sagittal view of the femoral implant of the present invention in extension, suitable for grinding resection.

[0065] Figure 15A It is a coronal schematic diagram of the femoral implant and tibial pad components of the knee joint prosthesis of the present invention when the femur is in neutral and extended position.

[0066] Figure 15B It is a coronal schematic diagram of the femoral implant and tibial pad components of the knee joint prosthesis of the present invention when the femur is in varus and extension, wherein the distal medial condyle is shorter than the distal lateral condyle.

[0067] Figure 15C It is a coronal schematic diagram of the femoral implant and tibial pad components of the knee joint prosthesis of the present invention when the femur is in valgus and extension, wherein the distal medial condyle is longer than the distal lateral condyle.

[0068] Figure 15D It is a coronal schematic diagram of the femoral implant and tibial pad components of the knee prosthesis of the present invention when the femur is in valgus and extension, wherein an angle is opened from the distal medial condyle to the distal lateral condyle.

[0069] Figure 15E It is a coronal schematic diagram of the femoral implant and tibial pad components of the knee prosthesis of the present invention when the femur is in varus and extension, wherein an angle is opened from the distal lateral condyle to the distal medial condyle.

[0070] Figure 16A It is a coronal schematic diagram of the tibial pad, tibial tray and tibial intramedullary stem of the knee joint prosthesis assembly of the present invention.

[0071] Figure 16B It is a coronal schematic diagram of the tibial pad, tibial tray and tibial intramedullary stem of the knee joint prosthesis combination of the present invention, wherein the tibial intramedullary stem is oriented at an angle.

[0072] Figure 16C It is a coronal schematic diagram of the tibial pad, tibial tray and tibial intramedullary stem of the knee prosthesis combination of the present invention, wherein the tibial surface facing the bone and the tibial intramedullary stem are oriented at different angles, resulting in a thinner thickness on the inner side of the tibial pad, which is beneficial for orientation when the knee joint is in varus.

[0073] Figure 16D Schematic diagram of the coronal view of the combined tibial pad, tibial tray and tibial intramedullary stem of the knee prosthesis of the present invention, wherein the tibial surface facing the bone and the tibial intramedullary stem are oriented at different angles and the distal lateral condyle is shorter than the distal medial condyle.

[0074] Figure 16E It is a coronal schematic diagram of the tibial pad, tibial tray and tibial intramedullary stem of the knee joint prosthesis combination of the present invention, wherein the tibial surface facing the bone, the tibial intramedullary stem and the distal tangents of the bilateral condyles are oriented at different angles.

[0075] Figure 17A It is a sagittal schematic diagram of the tibial pad, tibial tray and tibial intramedullary stem of the knee joint prosthesis combination of the present invention, showing the J curve determined by two radii.

[0076] Figure 17B FIG. 1 is a sagittal schematic diagram of the tibial pad, tibial tray and tibial intramedullary stem of the knee prosthesis combination of the present invention, showing a J-curve defined by two radii, wherein the tibial intramedullary stem is offset toward the front of the tibia.

[0077] Figure 17C FIG. 1 is a sagittal schematic diagram of the tibial pad, tibial tray and tibial intramedullary stem of the knee prosthesis combination of the present invention, showing a J-curve defined by two radii, wherein the tibial intramedullary stem is offset toward the posterior portion of the tibia.

[0078] Figure 17D It is a sagittal schematic diagram of the tibial pad, tibial tray and tibial intramedullary stem of the knee joint prosthesis combination of the present invention, showing the J curve defined by three radii.

[0079] Figure 17E It is a sagittal schematic diagram of the tibial pad, tibial tray and tibial intramedullary stem of the knee joint prosthesis combination of the present invention, showing the J curve defined by four radii.

[0080] Figure 17F FIG. 1 is a sagittal schematic diagram of the tibial pad, tibial tray, and tibial intramedullary stem of the knee prosthesis assembly of the present invention, showing a J-curve defined by two radii, wherein the tibial intramedullary stem and the tibial bone-facing surface are oriented at an angle.

[0081] Figure 17G FIG. 1 is a sagittal schematic diagram of the tibial pad, tibial tray, and tibial intramedullary stem of the knee prosthesis assembly of the present invention, showing a J-curve defined by three radii, wherein the tibial intramedullary stem and the tibial bone-facing surface are oriented at an angle.

[0082] Figure 17H FIG. 1 is a sagittal schematic diagram of the tibial pad, tibial tray, and tibial intramedullary stem of the knee prosthesis assembly of the present invention, showing a J-curve defined by four radii, wherein the tibial intramedullary stem and the tibial bone-facing surface are oriented at an angle.

[0083] Figure 17I It is a sagittal schematic diagram of the tibial pad, tibial tray and tibial intramedullary stem of the knee prosthesis combination of the present invention, showing a J curve defined by four radii, wherein the tibial intramedullary stem and the tibial surface facing the bone are oriented at an angle, and the tibial intramedullary stem is offset toward the posterior condyle.

[0084] Figure 18 1 is a top view of the tibial component of the knee joint prosthesis of the present invention

[0085] Figure 19A It is a coronal schematic diagram of the tibial tray and tibial intramedullary stem of the knee prosthesis of the present invention, showing the orientation angle.

[0086] Figure 19B It is a coronal schematic diagram of the tibial tray and tibial intramedullary stem of the knee prosthesis of the present invention, showing the orientation angle and offset.

[0087] Figure 19C It is a coronal schematic diagram of the tibial tray and tibial intramedullary stem of the knee prosthesis of the present invention, showing the orientation angle and offset.

[0088] Figure 19D It is a coronal schematic diagram of the tibial tray and tibial intramedullary stem of the knee joint prosthesis of the present invention, showing two orientation angles.

[0089] Figure 19E It is a coronal schematic diagram of the tibial tray and tibial intramedullary stem of the knee joint prosthesis of the present invention, showing two orientation angles.

[0090] Figure 20A It is a coronal schematic diagram of the tibial tray and tibial intramedullary stem of the knee joint prosthesis of the present invention, and the knee joint prosthesis is suitable for bone resection with an angle on the medial side.

[0091] Figure 20B It is a coronal schematic diagram of the tibial tray and tibial intramedullary stem of the knee joint prosthesis of the present invention, and the knee joint prosthesis is suitable for bone resection at a lateral angle.

[0092] Figure 20C It is a coronal schematic diagram of the tibial tray and the tibial intramedullary stem of the knee joint prosthesis of the present invention. The knee joint prosthesis is suitable for bone resection with a step on the medial side.

[0093] Figure 20D It is a coronal schematic diagram of the tibial tray and the tibial intramedullary stem of the knee joint prosthesis of the present invention, and the knee joint prosthesis is suitable for bone resection with a step on the outside.

[0094] Figure 21A Schematic diagram of the coronal plane of the femoral implant and the patellar component of the knee joint prosthesis of the present invention when the femur is in neutral position.

[0095] Figure 21BFIG. 1 is a coronal schematic diagram of a femoral implant and a patellar component of a knee joint prosthesis according to the present invention in a femoral varus position, wherein the distal lateral condyle is shorter than the distal medial condyle.

[0096] Figure 21C It is a coronal schematic diagram of the femoral implant and patellar component of the knee joint prosthesis of the present invention in the case of femoral valgus, wherein the distal lateral condyle is longer than the distal medial condyle.

[0097] Figure 22A Schematic diagram of the coronal plane of the patellar component of the knee joint prosthesis of the present invention.

[0098] Figure 22B Schematic diagram of the sagittal plane of the patellar component of the knee joint prosthesis of the present invention.

[0099] Figure 23 It is a cross-sectional schematic diagram of the patella component of the knee joint prosthesis of the present invention.

[0100] Figures 24A to 24F is a flow chart of another variation of the method of the present invention.

[0101] Figure 25A is a flow chart describing the different procedures of the present invention.

[0102] Figure 25B is a sketch / representation of a knee prosthesis of the present invention.

[0103] Figures 26A to 26D The partitioning and parameterization of the femoral component are described.

[0104] Those skilled in the art will understand that the elements in the drawings are shown for simplicity and clarity and are not necessarily drawn to scale. For example, in order to help improve the understanding of the invention and its implementation method, its size may be exaggerated relative to other elements. In addition, when the terms "first", "second", etc. are used in this article, their use is intended to distinguish similar elements and is not necessarily used to describe a sequence or chronological order. In addition, related terms such as "front", "back", "upper", and "lower" in the specification and / or claims are not necessarily used to describe exclusive relative positions. Therefore, those skilled in the art will understand that these terms are interchangeable with other terms, and the embodiments described herein can operate in directions different from those explicitly stated or otherwise described. DETAILED DESCRIPTION

[0105] The following description is not intended to limit the scope of the present invention in any way, as it is exemplary in nature and is used to describe the best mode of the present invention known to the inventors at the date of this application. Therefore, changes may be made to the arrangement and / or function of any elements described in the exemplary embodiments disclosed herein without departing from the spirit and scope of the present invention.

[0106] The invention makes it possible to recreate a knee joint that is like the original joint, because it not only takes into account the patient's entire knee joint movement behavior (current and pre-illness), but also his individual hip-knee-ankle (HKA) joint mechanics. The patellar joint can also be taken into account.

[0107] refer to Figures 1A-1B , shows the knee joint (1) in a sitting position (knee flexed), wherein the femur (10) and tibia (20) are joined by the medial meniscus (22) and the lateral meniscus (24), with contact on the femur being at the medial condyle (12) and the lateral condyle (14). Applicants have determined that the natural relative motion between the femur and tibia can be described as a combination of sliding and rolling motions of linear motion, such as medial / lateral translation (110), anterior / posterior translation (210), superior / inferior translation (310)) and rotation, such as flexion / extension (120), adduction / abduction (220), axial (inside / outside) rotation (320). Knee joint motion can be characterized as motion based on the femoral spiral axis, which is a combination of the flexion / extension axis and the longitudinal axis, the resulting spiral axis being dependent on knee joint shape and knee joint mechanical alignment. This combination of motions is different for each individual and can be altered by the patient's medical condition (lesions, trauma, etc.). Knee motion is based on the femoral spiral axis, which is a combination of the flexion / extension axis and the longitudinal axis. The resulting spiral axis depends on knee shape and knee mechanical alignment.

[0108] As is known, the prior art for knee prosthesis only considers anterior / posterior translation (120) and flexion / extension rotation (120), resulting in a rather simple prosthesis, but with the disadvantage that the surgeon has to implant an implant that does not conform to the anatomy of the body. Such prior art prostheses have been found to be satisfactory in terms of lifespan (93% increase after 15 years), but with low customer satisfaction (only 70%). Due to this situation, many patients who would benefit from the prosthesis postpone the surgery due to concerns about the risk of discomfort or pain. When the discomfort and pain prevent the patient from sleeping peacefully, the patient will request a knee prosthesis. The subject tries to control it with medication and wait as long as possible, but if he waits too long, it may make the surgery more difficult because the deviation and pathology of the knee joint may increase and affect the ligament tension and collateral joints. In some countries where medical expenses are important, patients go to the doctor very late, so bilateral knee replacements must be performed simultaneously (because the unhealthy knee joint bears the load for a long time, which will cause damage to the healthier knee joint).

[0109] Newer generations of prostheses still use the same limits for anterior / posterior translation (120) and flexion / extension rotation (120), but allow for tilting of the flexion / extension rotation (120) to more closely resemble the natural motion of the patient's knee. Since these prostheses have only been in use for a few years, their longevity and patient satisfaction are unknown. However, even in these cases, surgeons are attempting to anatomically implant prostheses that do not conform to the body's anatomy.

[0110] Now refer to Figures 2A-2B -2C, the invention described herein takes into account the broader aspects of the patient's anatomy. Humans not only have unique knee kinematics characterized by individualized knee morphology (the articular surfaces between the femur and tibia and between the femur and patella for a particular patient), but they also have individualized mechanical alignment of the hip, knee, and ankle (HKA). Normal mechanical alignment ( Figure 2A ), also called the "neutral" mechanical axis or the "upright" mechanical axis, represents the majority of the population, but variations from constitutional inversion (bow legs) ( Figure 2B ) to constitutional valgus (X-shaped legs) ( Figure 2C ) major changes.

[0111] Current state of the art suggests that all patients should be restored to normal mechanical alignment ( Figure 2A ) and the tilted mounting of the prosthesis is sufficient to adapt to the individualized knee joint of the patient. This mechanical alignment, also called "mechanical mechanical alignment", is characterized by neutral mechanical alignment and the positioning of the components perpendicular to the mechanical axis of the femur and tibia. The movement and attachment of the patella (40) are also ignored. Therefore, the knee prosthesis of the prior art can be produced as a standard in only a few sizes, which reduces the production costs. The difficulty when using such prostheses of the prior art is to mechanically and anatomically position the prosthesis that does not conform to the human anatomy, which leads to many compromises in positioning and size, which sometimes leads to the implantation of a prosthesis that is too large (with the risk of pain, loss of mobility) or a prosthesis that is too small (with the risk of increased subsidence or loosening), so that the newly created knee joint may generate new tensions and unnecessary pressure on the ligaments and bones that hold the joint together. The friction between these elements may cause discomfort or pain to the patient.

[0112] Now refer to Figure 3 The method 3000 according to the present invention comprises several steps, not necessarily in the following order. In a first step 3002, the patient's preoperative condition is assessed and / or measured using CT scan, X-ray, MRI, EOS (under weight-bearing or non-weight-bearing conditions, single foot, double foot, under varus / valgus stress), or any other measuring device and / or applying any method known in the art, including assessing / measuring at least one of the following patient conditions:

[0113] (a) HKA mechanical alignment (see Figure 2A 、 2B , 2C);

[0114] (b) relative motion of the femur to the tibia (combined sliding and rolling motion, e.g. Figure 1A );

[0115] (c) femoral and tibial contact surfaces and bone shape;

[0116] (d) The position and shape of the patella relative to the femur and tibia, and the contact surface between the patella and femur.

[0117] In a second step 3004, a target postoperative HKA mechanical alignment is determined based on sub-step (a) above and the patient's anatomical history (if known).

[0118] In a third step 3006, the target post-operative relative motion (sliding and rolling motion combined) of the femur to the tibia is determined according to the second step and sub-step (b) above.

[0119] In a fourth step 3010, the shapes of the contact surfaces of the femoral and tibial prostheses are determined according to the second and third steps and sub-step (c) above.

[0120] In a fifth step 3012, the shapes of the femoral and tibial prosthetic attachments are determined according to the fourth step and sub-step (c) above.

[0121] In a sixth step 3014, the target postoperative patellar position relative to the femoral component and relative to the tibial component is determined based on the second, third, and fourth steps, and sub-step (d) above, and the patient's anatomical history (if known).

[0122] In a seventh step 3016, the shape of the interface between the femoral prosthesis and the patella is determined according to the second, third, fourth, and sixth steps and the above sub-step (d) (only the interface between the femoral component and the patellar component, not the interface between the patellar component and the tibial component).

[0123] In an eighth step 3020, the above definitions are combined to determine a individually adjusted knee prosthesis.

[0124] Now refer to Figure 4 The method 4000 according to the present invention comprises several steps, not necessarily in the following order. The method 4000 is for selecting a 3D knee prosthesis model for a specific patient, the method comprising:

[0125] - Step 4002: (a) parameterizing the knee prosthesis according to well-defined and independent knee compartments, and

[0126] -Step 4004: (b) generating a large number of knee joint shapes by varying the shape parameters (surface and dimensions) of at least one of these compartments, wherein a suitable knee prosthesis can be selected from the generated knee joint shapes to match the patient's needs, since the generated configurations reproduce the high variability of the knee joint shapes, which reproduce the asymmetry of each individual knee joint 3D shape and thus can replicate the patient's knee joint motion.

[0127] With respect to step 4002 above, for each compartment, parameterization is achieved by adjusting two types of representations / sketches. The first type is to personalize the joint representation / sketch that defines the articular surface of each compartment by adjusting the guide curves of ML and AP in each plane (radius of curvature, offset, position of the origin of these guide curves to the patient's knee brace) so that the 3D shape of the prosthesis surface matches the patient's knee joint surface. The second type is to personalize the size sketch / representation along the joint surface (guide curves that define the outer limits) so that the size of the prosthesis around the joint is correctly adapted to the patient's size. The parameters define the orientation and position of these outer guide curves in each plane (radius, size, position of the origin of these guide curves to the patient's knee brace).

[0128] Now refer to Figure 5 Method 5000 according to the present invention includes several steps, not necessarily in the following order. Method 5000 prepares a database of 3D knee prosthesis models from which a 3D knee prosthesis model matching the needs of a particular patient can be selected. The method includes the following steps, not necessarily in the following order.

[0129] - Step 5002: (a) parameterizing the selected knee prosthesis design configuration to correspond to well-defined and independent knee compartment characteristics;

[0130] - Step 5004: (b) generating a plurality of 3D knee prosthesis models corresponding to at least one compartment by varying shape parameters such as surface and size, and reproducing 3D shape asymmetry of a sample population of individual knee joints; and

[0131] - Step 5006: (c) populating the database with the generated models, thereby generating a database of 3D knee prosthesis models with high variability;

[0132] - Step 5010: (d) studying the motion of the patient's knee joint using 3D scanning;

[0133] - Step 5012: (e) adjusting the lesion and optionally adjusting the soft tissue effects to create a pre-lesion model of a hypothetical patient knee joint motion;

[0134] - Step 5014: (f) selecting one or more models from a list of available knee prostheses or from a database of 3D knee prosthesis models that best replicate the assumed pre-lesion knee kinematic model of the patient as defined by the 3D shape asymmetry of the patient's knee;

[0135] - Step 5016: (g) if there is no matching knee prosthesis in inventory, manufacturing the selected prosthesis model;

[0136] - Step 5020: (h) preparing the obtained prosthesis for implantation.

[0137] Now refer to Figure 6 The method 6000 according to the present invention comprises several steps, not necessarily in the following order. A knee prosthesis is provided, which is manufactured according to the 3D model selected after applying the method 6000, comprising the following steps:

[0138] - Step 6002: (a) analyzing the patient's current and pre-lesion knee joint motion behavior and the patient's HKA mechanical alignment,

[0139] - Step 6004: (b) selecting a suitable 3D model from a comprehensive database of 3D models of different knee joint morphologies, each 3D model being adapted to the known morphology and the production constraints and requirements,

[0140] - Step 6006: (c) manufacturing the selected 3D model representing a producible and customized knee prosthesis that fits the individual patient's 3D anatomy, thereby enabling reconstruction of a natural-like knee joint.

[0141] Now refer to Figure 7A and 7B The femur is shown in an axial view. Among people with pre-arthritic or native knees (those without any pathology in the knee joint), there is a wide range of variability in the following:

[0142] Knee joint dimensions

[0143] Knee joint shape

[0144] Knee size

[0145] Body mechanics alignment.

[0146] Some people with healthy knees are:

[0147] Constitutional inversion mechanical alignment (limb O-shaped);

[0148] Constitutional valgus mechanical alignment (X-shaped limb); or

[0149] Constitutional neutral mechanical alignment (I-shaped limbs).

[0150] Deviated limb alignment (varus or valgus) in those healthy knees is not considered a misalignment, but rather a constitutional limb alignment that is deviated.

[0151] Within the knee joint, some parameters vary greatly within the same population, so for knee joints of the same size, their shape may vary significantly.

[0152] The main parameters that function on the joint are as follows:

[0153] Alpha (α): The angle between FMA and BCD

[0154] DCA: The angle between TEA and BCD

[0155] PCA: An angle between TEA and BCP

[0156] ATA: The angle between TEA and TL

[0157] SA: Groove shaft (connects KC to TG)

[0158] WL: Whiteside Line, connecting KC and TGL

[0159] All of these parameters may vary from each other by more than 15° (each angular parameter can vary by 7.5° from its mean, which means that in healthy people the range of variation for each parameter is estimated to be 15° – a Gaussian curve).

[0160] These variations may be attributable to genetics (hereditary), ontogeny during growth prior to skeletal maturity, posture and / or activity and / or weight, sex, morphotype (endomorph, ectomorph, mesomorph), or activities of daily living associated with deep knee flexion.

[0161] Every knee joint has a close relationship between its geometry and the surrounding soft tissue envelope, particularly the cruciate, collateral, and retinacular ligaments. If the knee joint shape changes after implantation of a knee prosthesis, the relationship between the ligament insertion points and the articular surface can change. This can not only make proper balance between the medial and lateral compartments difficult or impossible, but also cause problems in extension, flexion, and hemiflexion.

[0162] Now refer to Figures 8A to 8B, showing the close relationship between knee joint mechanical alignment, knee joint size and shape, and ligament insertion and length (collateral, cruciate, and retinaculum ligaments). The medial collateral ligament 422 connects the femur 410 and tibia 420. The cruciate ligament 424 connects the femur 410 and tibia 420. The lateral collateral ligament 432 connects the femur 410 and fibula 430. The medial patellar retinaculum 442 connects the femur 410 and patella 440 medially. The lateral patellar retinaculum 444 connects the femur and patella 440 laterally.

[0163] Now refer to Figures 9A to 9C , represents the femoral implant of the knee joint prosthesis of the present invention, and the following elements are for reference:

[0164] The bone-facing surface 510,

[0165] Articular surface 520,

[0166] the condylar portion 522 of the medial condyle,

[0167] the condylar portion 524 of the lateral condyle,

[0168] Pulley portion 526,

[0169] Medial protuberance 532,

[0170] Lateral protuberance 534,

[0171] Pulley depth 536,

[0172] Intermediate outer curve 540,

[0173] the medial end 542 of the medial lateral curve,

[0174] The outer end 544 of the middle outer curve,

[0175] J-curve condyle 550,

[0176] J curve condyle anterior part 552,

[0177] J curve condyle posterior 554,

[0178] J-curve pulley 560.

[0179] Now refer to Figures 10A to 10C , represents the knee joint prosthesis of the present invention, the elements are as follows:

[0180] Femoral component 610,

[0181] The bone-facing surface 612 of the medial femur,

[0182] External articular surface 614,

[0183] Tibial pad component 620,

[0184] The corresponding articular surface 624,

[0185] Tibial tray component 630,

[0186] The bone-facing surface 632 of the medial tibia,

[0187] Patella component 640,

[0188] The medial bone-facing surface 642 of the patella,

[0189] Patellar articular surface 644.

[0190] Now refer to Figures 11A to 11D , a comparison between the knee joint prosthesis of the prior art and the knee joint prosthesis according to the present invention is clearly visible.

[0191] Comparison with standard (off-the-shelf) knee prostheses and limitations of this system:

[0192] Because a knee prosthesis or knee implant is not anatomical (in that it only roughly matches the anatomical motion of the human knee) and must be implanted in a manner that more or less matches the patient's knee anatomy, many significant simplifications and compromises have to be incorporated in the design of a knee prosthesis.

[0193] The initial goal was to mechanically optimize the implantation of the prosthesis to achieve longevity or life expectancy. These knee prostheses were always designed to be mechanically implanted (cut at 90° to the mechanical axis in the coronal plane) with symmetrical condylar shape and thickness for neutral limb mechanics.

[0194] However, different companies' knee prostheses across the size range have implemented dogmatic concepts that compromise shape, size, and mechanical alignment to achieve the average knee and limb morphology. These concepts include:

[0195] The number of sizes is typically limited to 10. However, this is not practical for the wide range of knee sizes, from small to very wide, as the smallest size for the Caucasian population is not suitable for the corresponding size for the Asian population. Furthermore, most companies increase the size range by adding a size between two sizes rather than increasing the size at the extremes.

[0196] The medial-to-lateral / front-to-back ratio was thought to be fixed, but we now know that it varies significantly within the population, and the phenomenon of oversizing or undersizing prostheses has been well described.

[0197] The sagittal shape of the condyle and / or trochlea (J-curve) is often simplified as single-radius, double-radius, or multiple-radius, but we now know that some patients have single-radius or multiple-radius J-curves.

[0198] • The femoral-patellar joint is often simplified as having a fixed orientation of the groove axis, but we now know that the groove axis is not oriented in this way if the distal femur is in varus or valgus.

[0199] Fifth, condylar offset is almost never considered, with the exception of the Smith & Nephew Journey knee, which sets the medial, distal, and posterior condylar offsets at a fixed 2.5 mm, but we now know that the inclination of the joint line varies significantly between the distal and posterior condyles and across populations.

[0200] Today, clinical results 15 years after implantation show that knee prosthesis survival rates exceed 93%. However, 30% of patients complain of dissatisfaction with total knee replacement surgery, including pain, loss of mobility, or abnormal kinematics.

[0201] Another challenge today is that the population requiring total knee replacements is younger and still very active. Consequently, knee function and overall satisfaction are becoming increasingly important. Consequently, the trend is to fit non-anatomically correct knee prostheses as closely as possible to the anatomy. This improves prosthetic function, but carries the risk of shortening the lifespan of the knee prosthesis and, as a result, increasing the risk of premature component loosening.

[0202] Knee implants (standard knee implants, patient-specific or personalized / individualized or custom implants) are described as follows:

[0203] Now refer to Figures 9A to 9C and Figures 10A to 10C , a knee prosthesis comprises a femoral component and a tibial tray component (with padding) and a patellar component, which is designed based on patient-specific data (from literature, cadavers and 3D images) to define a standard range of knee prostheses or to define a patient-specific prosthesis.

[0204] The inner, bone-facing surface of the femoral component is consistent with the corresponding surface of the femoral condyle. Alternatively, it can be consistent with one or more optimal bone cuts on the femoral condyle. However, the outer articular surface of the component is reinforced to form a smooth surface with a nearly constant radius in the coronal plane. The corresponding articular surface of the tibial tray (liner) has a surface profile in the coronal plane that matches the outer articular surface.

[0205] In certain embodiments, the articular surface of the component comprises a sagittal curvature that reliably matches the patient's existing or healthy sagittal radius.

[0206] Modern knee prostheses:

[0207] Symmetrical condyles;

[0208] The thickness of the distal and posterior condyles is the same between the medial and lateral condyles, but can vary between the distal and posterior parts.

[0209] The tangents of the distal and posterior condyles are parallel to the knee prosthesis flexion axis;

[0210] The trochlear projection is fixed and parallel to the tangent line of the posterior condyle (axial plane);

[0211] No condylar offset (except S&N, 2.5mm offset);

[0212] The fixed groove axis is oriented laterally by about 6° or laterally eccentric;

[0213] The inventive activity of the present invention is also to enable the medial femorotibial joint to the lateral femorotibial joint to the femoropatellar joint to be changed independently of each other. This can be defined as the variable parameters as follows:

[0214] Personalized knee prosthesis:

[0215] Distal condylar offset (not fixed) = alpha distal angle αd

[0216] Posterior condylar offset (non-fixed value) = alpha posterior angle αp

[0217] ·Offset of the trochlear protuberance (not a fixed value)

[0218] αd and αp can be equal or unequal, and can also be equal or unequal to the trochlear anterior angle (ATA)

[0219] DCA and αd can be equal or unequal

[0220] PCA and αp can be equal or unequal

[0221] SA is not a fixed value (groove axis = γ1)

[0222] WL is not a fixed value (Whiteside line = γ2)

[0223] The difference between standard (STD), off-the-shelf (OTS) prostheses and the personalized knee prosthesis of this invention:

[0224] Now refer to Figures 11A to 11D , showing significant differences between the STD (OTS) prosthesis and the personalized knee prosthesis of the present invention. Figure 11A Figures 11A (coronal) and 11C (axial) show a standard femoral knee component defined by the distal and posterior prosthetic joint lines (DCA, PCA) parallel to the prosthetic knee flexion axis with fixed sulcus axis and Whiteside line orientations (SA, WL). The trochlear lines are also oriented parallel or with a fixed angle in flexion (ATA).

[0225] Special reference Figure 11B (Coronal) and 11D (Axial) views show a customized knee prosthesis with distal and posterior prosthetic joint lines deviated (or tilted) toward the prosthetic knee flexion axis. The distal and posterior angles (DCA, PCA) are independent of each other and each has independent sulcus axis and Whiteside line orientations (SA, WL). The trochlear line orientation changes independently of the posterior condylar joint line (variable angle) during flexion (ATA).

[0226] Now refer to Figures 12A-12K The main geometric parameters describing the femoral part of the knee prosthesis of the present invention are defined as follows:

[0227] 802: Femur

[0228] 810: Femoral Implants

[0229] 812: Medial condyle

[0230] 814: Lateral condyle

[0231] 820: Middle outer dimension (ML)

[0232] 822: Dimension from medial condyle to femoral mechanical axis (FMA, 836)

[0233] 824: Dimension from lateral condyle to femoral mechanical axis (FMA, 836)

[0234] 826: Femoral Anatomical Axis (FAA)

[0235] 830: Intercondylar axis

[0236] 832: Medial condylar axis defined at the most distal point of the femoral mechanical axis (FMA, 836)

[0237] 834: Lateral condylar axis defined at the most distal point of the femoral mechanical axis (FMA, 836)

[0238] 836: Femoral Mechanical Axis (FMA)

[0239] 838: HKS: Angle between FAA 826 and FMA 836

[0240] 846: Transepicondylar axis (TEA)

[0241] 852: medial condylar surface

[0242] 854: Lateral condylar surface

[0243] 856: Distal tangent of medial and lateral condyle (BCD)

[0244] 858: Angle between FMA 836 and BCD 856

[0245] Special References Figure 12A and Figure 12B , for a given medial-lateral dimension (ML) 820, the medial condyle dimension 822 and the lateral condyle dimension 824 measured from the femoral mechanical axis (FMA) 836 can be twice as wide as the other in the coronal (distal condyle) or axial (posterior condyle) planes.

[0246] Similarly, the dimensions of the medial condylar axis 832 and the lateral condylar axis 834 measured from the femoral mechanical axis (FMA) 836 may differ from each other by up to 10 mm.

[0247] refer to Figures 12C-12K , examples show the changes in the posterior and distal condyles achieved by the knee prosthesis of the present invention.

[0248] Now refer to Figure 12C 、 Figure 12D 、 Figure 12H 、 Figure 12I , the dimensions of the condyles 812, 814 may vary by up to 10 mm relative to each other.

[0249] Now refer to Figure 12E 、 Figure 12F 、 Figure 12J 、 Figure 12K The angle 858 between the femoral mechanical axis (FMA) 836 and the medial and lateral condyle distal tangent (BCD) 856 can vary by up to 15° medially or laterally, distally or posteriorly.

[0250] Now refer to Figure 12G 、 Figure 12H 、 Figure 12I 、 Figure 12J 、 Figure 12K , variations and differences between the condyles 812, 814 can be adjusted independently of the angle between the femoral anatomical axis (FAA) 826 and the femoral mechanical axis (FMA) 836. In other words, all adjustments to the condyles 812, 814 can be made independent of the prosthesis size and the patient's hip-knee-ankle (HKA) mechanical alignment, whether normal, varus, or valgus.

[0251] Now refer to Figures 13A-13C , other parameters describing the femoral portion of the knee prosthesis of the present invention, particularly those related to shape, surface and contour, are defined as follows:

[0252] 912: Medial condyle

[0253] 914: Lateral condyle

[0254] 936: Femoral Mechanical Axis (FMA)

[0255] 946: Transepicondylar axis (TEA)

[0256] 952: Medial condylar surface

[0257] 953: Pulley surface

[0258] 954: Lateral condylar surface

[0259] 962: Shape radius of the medial condyle surface in the coronal and cross-sectional planes

[0260] 963: Shape radius of the trochlear surface in the coronal plane

[0261] 964: Shape radius of the lateral condylar surface in the coronal and cross-sectional planes

[0262] 972: Shape of the medial condyle surface in the sagittal plane (medial condyle J curve)

[0263] 973: Shape of the trochlear surface in the sagittal plane (trochlear J curve)

[0264] 974: Shape of the lateral condyle surface in the sagittal plane (lateral condyle J curve)

[0265] 982: Medial profile angle of the anterior surface of the femoral implant in the coronal plane

[0266] 984: Lateral profile angle of the anterior surface of the femoral implant in the coronal plane

[0267] 992: Medial profile angle of the posterior surface of the femoral implant in cross-sectional and coronal planes

[0268] 994: Lateral profile angle of the posterior surface of the femoral implant in cross-sectional and coronal planes

[0269] Now refer to Figure 13A and Figure 13B, the shape radius 962 of the medial condyle surface in the coronal plane and cross-section, the shape radius 963 of the trochlear surface in the coronal plane, and the shape radius 964 of the lateral condyle surface in the coronal plane and cross-section can be adjusted independently of each other and independently of the prosthesis size and the patient's hip-knee-ankle (HKA) mechanical alignment, whether neutral, varus or valgus. It is important that the contour (the external dimensions of the implant) does not exceed or fall below the resection area, so that resurfacing is required. The shape radius 962 of the medial condyle surface in the coronal plane and cross-section, the shape radius 963 of the trochlear surface in the coronal plane, and the shape radius 964 of the lateral condyle surface in the coronal plane and cross-section can all be varied from 15 mm to 65 mm. The adjustment of all contour angles 982, 984, 992, 994 for the anterior and posterior surfaces of the femoral implant can be independent of each other and have nothing to do with the prosthesis size and the patient's hip-knee-ankle (HKA) mechanical alignment, whether normal, varus or valgus. All profile angles 982, 984, 992, 994 for the anterior and posterior faces of the femoral implant may vary between 0° and 50°.

[0270] Now refer to Figure 13C , the shape of the medial condyle surface in the sagittal plane (medial condyle J curve) 972, the shape of the trochlear surface in the sagittal plane (trochlear J curve) 973, and the shape of the lateral condyle surface in the sagittal plane (lateral condyle J curve) 974 can be adjusted independently of each other and are independent of the prosthesis size and the patient's hip-knee-ankle (HKA) mechanical alignment (whether normal, varus, or valgus). The shape of the medial condyle surface in the sagittal plane (medial condyle J curve) 972, the shape of the trochlear surface in the sagittal plane (trochlear J curve) 973, and the shape of the lateral condyle surface in the sagittal plane (lateral condyle J curve) 974 can be composed of a single radius or a combination of two or more radii, the sizes of which can vary from 15 mm to 65 mm. When a combination of radii is used, the transition from one radius to the next can be smoothed by using a spline curve or any other appropriate curve, for example, applying "SOLIDWORKS" TM Provided curve or surface fitting algorithm.

[0271] Now refer to Figures 14A-14L The femoral part of the knee prosthesis of the present invention can be applied to any bone resection, such as plane resection ( Figure 14A 、 Figure 14B ), oblique resection ( Figure 14C 、 Figure 14D ))、Curve Resection( Figure 14E 、 Figure 14F ), offset cut( Figure 14G 、 Figure 14H ), double oblique resection ( Figure 14I 、 Figure 14J) or any other bone resection technique that suits the individual patient's needs. Bone resection can be sawing ( Figure 14K ) or grinding ( Figure 14L ), or any other suitable technique known in the art may be used.

[0272] Now refer to Figures 15A to 15E The main geometric parameters describing the femoral implant and tibial pad components of the knee prosthesis of the present invention are defined as follows:

[0273] 1102: Femur

[0274] 1110: Femoral Implant

[0275] 1112: Medial condyle

[0276] 1114: Lateral condyle

[0277] 1120: Center outer dimension (ML)

[0278] 1122: Dimension from the femoral mechanical axis (FMA, 1136) to the medial condyle

[0279] 1124: Dimension from the femoral mechanical axis (FMA, 1136) to the lateral condyle

[0280] 1126: Femoral Anatomical Axis (FAA)

[0281] 1130: Intercondylar axis

[0282] 1132: Dimension from the femoral mechanical axis (FMA, 1136) to the medial condyle center axis

[0283] 1134: Dimension from the femoral mechanical axis (FMA, 1136) to the central axis of the lateral condyle

[0284] 1136: Femoral Mechanical Axis (FMA)

[0285] 1146: Transepicondylar axis (TEA)

[0286] 1152: Medial condyle surface of femoral implant

[0287] 1153: Trochlear surface of femoral implant

[0288] 1154: Lateral condylar surface of femoral implant

[0289] 1156: Bicondylar Distal Tangent (BCD) of Femoral Implant

[0290] 1160: Tibial Pad Components

[0291] 1162: Surface of the tibial pad component corresponding to the medial condyle

[0292] 1163: Surface of the tibial pad component corresponding to the pulley

[0293] 1164: Surface of the tibial pad component corresponding to the lateral condyle

[0294] 1166: Distal tangent of the medial and lateral condyles of the tibial pad component

[0295] In the knee prosthesis according to the present invention, the tibial pad component 1160 is made to match the femoral implant 1110 ("match" means that the shapes interact across adjacent bone compartments by applying known curve / surface fitting and smoothing techniques, such as those used in "SOLIDWORKS"™ and the like, for example). In other words, the tibial pad component 1160 and the femoral implant 1110 share:

[0296] The same or substantially the same medial and lateral dimensions 1120,

[0297] The medial condyle is the same or substantially the same size as the femoral mechanical axis 1122,

[0298] The lateral condyle is the same or substantially the same distance from the mechanical axis of the femur.

[0299] The same or substantially the same intercondylar axis size 1130,

[0300] The medial condyle center axis is the same or substantially the same as the femoral mechanical axis 1132,

[0301] The center axis of the lateral condyle is the same or substantially the same as the mechanical axis of the femur 1134,

[0302] The same or substantially the same transepicondylar axis 1146 such that:

[0303] The medial condyle surface 1152 of the femoral implant matches the surface 1162 of the corresponding tibial pad of the medial condyle.

[0304] The trochlea surface 1153 of the femoral implant matches the surface 1163 of the tibial pad to which the trochlea corresponds.

[0305] The lateral condyle surface 1154 of the femoral implant matches the surface 1164 of the corresponding tibial pad of the lateral condyle, and

[0306] The bicondylar distal tangent line 1166 of the tibial pad matches the bicondylar distal tangent line 1166 of the tibial pad component. Figures 15B to 15E , showing several examples of how the knee prosthesis of the present invention can be adapted to the needs of individual patients.

[0307] Special References Figure 15B, shows the knee prosthesis of the present invention in a case of femoral varus, wherein the distal lateral condyle of the femoral implant 1110 is shorter than the distal medial condyle, creating an offset 1172 between the condyles, with essentially the same offset 1172 being reproduced in the tibial pad 1160.

[0308] Now refer to Figure 15C , shows a knee prosthesis of the present invention in a case of femoral valgus, wherein the distal lateral condyle of the femoral implant 1110 is longer than the distal medial condyle, creating an offset 1174 between the condyles, the same or substantially the same offset 1174 being reproduced in the tibial pad 1160.

[0309] Now refer to Figure 15D , shows a knee prosthesis of the present invention in a case of femoral varus, wherein the femoral implant 1110 has an angle 1182 that opens from the distal lateral condyle to the distal medial condyle, the same or substantially the same angle 1182 being reproduced in the tibial pad 1160.

[0310] Now refer to Figure 15E , shows the knee prosthesis of the present invention in a case of femoral valgus, wherein the femoral implant 1110 has an angle 1184 flaring from the distal medial condyle to the distal lateral condyle, the same or substantially the same angle 1184 being reproduced in the tibial pad component 1160.

[0311] In the knee prosthesis of the present invention, the offsets 1172, 1174 may vary from 0 to 10 mm, and the angles 1182, 1184 may vary from 0° to 15°.

[0312] Now refer to Figures 16A-16E , schematically shows a coronal view of the geometric shape of the tibial pad, tibial tray and tibial intramedullary stem combination of the knee joint prosthesis of the present invention. The main parameters in the coronal view are defined as follows:

[0313] 1262: Surface of the tibial pad corresponding to the medial condyle

[0314] 1263: Surface of the tibial pad corresponding to the pulley

[0315] 1264: Surface of the tibial pad corresponding to the lateral condyle

[0316] 1266: Distal tangent of the medial and lateral condyles of the tibial pad component

[0317] In practice, the tibial pad, tibial tray and tibial intramedullary stem can be realized in one or more parts and assembled by any suitable technique well known in the industry, and such assembly can be performed before or during surgery. For the purpose of the present description, these elements are presented as if they are manufactured in one component with different parts: (i) the articular surface of the tibial pad, including the surface 1262 corresponding to the medial condyle, the surface 1263 corresponding to the pulley and the surface 1264 corresponding to the lateral condyle, (ii) the bone-facing surface 1230 of the tibial tray and (iii) the tibial intramedullary stem 1240. In the knee prosthesis of the present invention, any orientation angle, any offset and any combination thereof applied to the tibial pad, tibial tray and tibial intramedullary stem are to adapt to the needs of individual patients.

[0318] Now refer to Figure 16B To accommodate the needs of individual patients, the tibial intramedullary stem 1240 is not orthogonal to the bone-facing surface 1230, but is oriented at an angle 1242.

[0319] Now refer to Figure 16C To accommodate individual patient needs, the tibial intramedullary stem 1240 is not orthogonal to the bone-facing surface 1230, but rather is oriented at an angle 1242, and the bone-facing surface 1230 is oriented at an angle 1232. As shown in this example, a thinner medial pad thickness facilitates varus knee orientation.

[0320] Now refer to Figure 16D To accommodate the needs of individual patients, the tibial intramedullary stem 1240 is not orthogonal to the bone-facing surface 1230, but is oriented at an angle 1242, the bone-facing surface 1230 is oriented at an angle 1232, and the surface 1264 corresponding to the lateral condyle is offset 1265.

[0321] Now refer to Figure 16E To accommodate individual patient needs, the tibial intramedullary stem 1240 is not orthogonal to the bone-facing surface 1230, but is oriented at an angle 1242, the bone-facing surface 1230 is oriented at an angle 1232, and the medial and lateral condyle distal tangents 1266 are oriented at an angle 1267. In the knee prosthesis of the present invention, the offset 1265 can vary from 0 to 10 mm, and the orientation angles 1232, 1242, 1267 can vary by up to 12°.

[0322] Typically, the offset varies from -10° to +10° in the medial-lateral or anteroposterior dimension and can be oriented up to 12° about the longitudinal axis of the tibial intramedullary stem.

[0323] Now refer to Figures 17A-17I, schematically depicting the sagittal geometry of the combined tibial pad 1320, tibial tray 1330, and tibial intramedullary stem 1340 of the knee prosthesis of the present invention, as if they were manufactured as a single piece 1300. In practice, the tibial component 1300 of the knee prosthesis of the present invention can be implemented in one or more parts and assembled using any suitable technique known in the industry, which can be performed before or during surgery. In these simplified figures, only one sagittal J-curve 1310 is shown; however, this J-curve 1310 could also represent the surface of the tibial component 1300 upon which the medial condyle, trochlea, or lateral condyle of a femoral implant of the present invention abuts.

[0324] The sagittal J curve 1310 is adapted to cooperate with the corresponding surface of the femoral implant of the present invention so that the function of the knee prosthesis of the present invention is adapted to the needs of the individual patient. To this end, the sagittal J curve 1310 can be made of one radius, but can also be made of two radii 1312, 1313 ( Figure 17A 、 Figure 17B 、 Figure 17C 、 Figure 17F ), three radii 1312, 1313, 1314 ( Figure 17D 、 Figure 17G ) or more radius 1312, 1313, 1314, 1315 ( Figure 17E 、 Figure 17H 、 Figure 17I ) and its size can vary from 15mm to 80mm.

[0325] To fit the tibia of an individual patient, the tibial intramedullary stem 1340 of the tibial component 1300 of the knee prosthesis of the present invention can be placed at the center of the tibial component 1300 in the sagittal plane ( Figure 17A 、 Figure 17D 、 Figure 17E 、 Figure 17F 、 Figure 17G 、 Figure 17H ), can be directed to the anterior tibia ( Figure 17B ) or to the posterior tibia ( Figure 17C 、 Figure 17I ) presents an offset 1342. In the knee prosthesis of the present invention, the offset 1342 can vary from 0 to 10 mm.

[0326] Also to fit the tibia of an individual patient, in the sagittal plane, the bone-facing surface 1332 of the tibial component 1300 of the knee prosthesis of the present invention may be oriented at an angle 1344 ( Figure 17F 、 Figure 17G 、 Figure 17H , Figure 17I In the knee prosthesis of the present invention, the angle 1344 can vary up to 12°.

[0327] The tibial component 1300 of the knee prosthesis of the present invention may incorporate any and all features described in this disclosure to better match the needs of an individual patient. Figure 17I ).

[0328] Typically, the offset varies from -10° to +10° in the medial-lateral or anteroposterior dimension and can be oriented up to 12° about the longitudinal axis of the tibial intramedullary stem.

[0329] Now refer to Figure 18 , the parameters defining the profile 1410 of the tibial component 1400 are as follows:

[0330] 1412: Medial condyle

[0331] 1414: Lateral condyle

[0332] 1422: Anteromedial condyle

[0333] 1424: Anterolateral condyle

[0334] 1432: Posteromedial condyle

[0335] 1434: Posterolateral condyle

[0336] 1442: Anteroposterior dimension of the anteromedial condyle (APam)

[0337] 1444: Anteroposterior dimension of the anterolateral condyle (APal)

[0338] 1452: Anteroposterior dimension of the posteromedial condyle (APpm)

[0339] 1454: Anteroposterior dimension of the anterolateral condyle (APal)

[0340] 1462: Anterior-posterior dimension of the medial condyle (APm)

[0341] 1464: Anterior-posterior dimension of the lateral condyle (AP1)

[0342] 1470: Internal and external dimensions (ML)

[0343] 1472: Inner and outer dimensions of the medial condyle (MLm)

[0344] 1474: Inner and outer dimensions of the lateral condyle (ML1)

[0345] In the knee prosthesis of the present invention, all of these parameters can be adjusted to suit the needs of the individual patient. In this prosthesis, the medial-lateral dimension 1470 can vary from 40 mm to 150 mm, the medial-lateral dimensions 1472, 1474 of the condyles can each independently vary from 15 mm to 70 mm, and the anterior-posterior dimensions 1442, 1444 of the condyles can each independently vary from 30 mm to 70 mm.

[0346] Now refer to Figures 19A-19E , the tibial tray 1530 of the knee prosthesis of the present invention can be adjusted to meet the needs of the individual patient (optimal component range and fixation).

[0347] In the coronal plane, the bone-facing surface 1532 may exhibit a certain orientation angle 1534, and the surface to which the tibial pad is attached may also exhibit a certain offset 1535 ( Figure 19B 、 Figure 19C ) or another orientation angle 1536 ( Figure 19D 、 Figure 19E In the knee prosthesis of the present invention, angles 1534, 1536 can vary between -12° and +12°, and offset 1535 can vary between 0 and 10 mm in medial and / or lateral dimensions and can be oriented up to 45°. The tibial tray 1530 of the knee prosthesis of the present invention can incorporate any and all features described herein to suit the needs of an individual patient.

[0348] Now refer to Figures 20A-20D The tibial tray 1630 of the knee prosthesis of the present invention can be adapted to any bone resection geometry to meet the needs of individual patients. In the coronal plane, the bone-facing surface 1632 can be on the medial ( Figure 20A ) or outside ( Figure 20B ) has a certain resection angle 1634, or on the inside ( Figure 20C ) or outside ( Figure 20D ) has a resection step 1635. In the knee prosthesis of the present invention, angle 1634 can be varied from -12° to +12°, and step 1635 can be varied from 0 mm to 10 mm medially and / or laterally and oriented up to 45°. The tibial tray 1630 of the knee prosthesis of the present invention can incorporate any and all features described in this disclosure to meet the needs of an individual patient.

[0349] Now refer to Figures 21A to 21C , in the coronal plane, the parameters determining the geometric shape of the patellar component of the knee prosthesis of the present invention are as follows:

[0350] 1852: Medial condyle surface of femoral implant.

[0351] 1853: Trochlear Surface of Femoral Implants

[0352] 1854: Lateral condylar surface of femoral implant

[0353] 1862: Articular surface of the patellar component corresponding to the medial condyle

[0354] 1863: Articular surface of the patellar component corresponding to the trochlea

[0355] 1864: Articular surface of the patellar component corresponding to the lateral condyle

[0356] 1870: Internal and external dimensions of the patellar component

[0357] 1872: Inner and outer dimensions of the medial side of the patellar component

[0358] 1874: Inner and outer dimensions of the lateral patellar component

[0359] The geometry of the patellar component of the knee prosthesis of the present invention is modified to suit the needs of an individual patient. The articular surfaces 1862, 1863, 1864 of the patellar component are made to match the corresponding surfaces 1852, 1853, 1854 of the femoral component, taking into account whether the patient's hip-knee-ankle (HKA) alignment is normal, varus, or valgus. As an example, in a case where the femoral component has an offset ( Figure 21C In 1872, Figure 21B 1874 in the figure), the offsets 1872 and 1874 are reproduced in the patella component.

[0360] Now refer to Figure 22A and 22B , shows the patellar component of the knee prosthesis of the present invention. In order to match the needs of individual patients, the medial and lateral surfaces ( Figure 22A ) can be symmetrical or asymmetrical between the medial and lateral compartments, and the anterior and posterior surfaces can be symmetrical or asymmetrical between the anterior and posterior compartments ( Figure 19B ). Figure 22A is a lateral view showing the medial and lateral compartments. Figure 22B This is a side view showing the anterior and posterior compartments. The four compartments may or may not be symmetrical.

[0361] Now refer to Figure 23 , the parameters for determining the profile 2010 of the patella component 2000 are as follows:

[0362] 2022: Anteromedial Compartment

[0363] 2024: Anterolateral Compartment

[0364] 2032: Posteromedial compartment

[0365] 2034: Posterolateral compartment

[0366] 2042: Anterior-posterior dimension of the medial side (APm)

[0367] 2044: Lateral front-back dimension (AP1)

[0368] 2052: Anteroposterior dimensions of the anteromedial compartment (Appam)

[0369] 2054: Anteroposterior dimension of the anterolateral compartment (APal)

[0370] 2062: Anteroposterior dimension of the posteromedial compartment (APpm)

[0371] 2064: Anteroposterior dimension of the posterolateral compartment (APPl)

[0372] 2070: Internal and external dimensions (ML)

[0373] 2072: Inside and outside dimensions (MLm)

[0374] 2074: External inner and outer dimensions (ML1)

[0375] In the knee prosthesis of the present invention, all of these parameters can be modified to suit the needs of individual patients. Each of the four compartments (medial, lateral, anterior, and posterior) can be determined to fall within the range of 8 mm to 30 mm in width and height. These values ​​are independent of patellar thickness, which should be at least 6 mm or more.

[0376] The main features of the present invention are:

[0377] The design specificities of the present invention regarding the distal and posterior condylar to trochlear portions of the femoral component are personalized features that, when put together, can realign the affected limb as it was before the injury and reshape the joint surface as closely as possible to the shape and size of the pre-arthritic knee.

[0378] Different types of correction:

[0379] From pathologically deviated limb alignment to pre-arthritic limb alignment;

[0380] From the affected knee joint surface to the arthritic anterior knee joint surface (both condyles and trochlea), this involves the medial and lateral curves of the joint surface and the sagittal J-curves of both condyles and trochlea;

[0381] From the pathological femoral (distal, posterior and in between), proximal tibial and trochlear joint lines to the corresponding pre-arthritic joint lines (= condylar deviation, trochlear deviation between the medial and lateral compartments);

[0382] · The distance from the depth of the diseased trochlea to the distance between the medial and lateral trochlear eminences, to the corresponding pre-arthritic distance;

[0383] · The coronal plane distance from the sagittal axis of the diseased condyle and trochlea to the middle of the knee joint to the corresponding pre-arthritic distance;

[0384] Supplementary corrections (or supplementary regulations, that is, the rules we use internally to avoid abnormal values of mechanical alignment and shape, whose range determines normal and abnormal mechanical alignment and shape, thus indicating which are reproduced or adjusted) can be made to the native or pre-arthritic limb mechanical alignment and knee joint shape:

[0385] · When the pre-arthritic limb alignment is considered mechanically unstable (too deviated, if the postoperative varus HKA exceeds 5° or valgus HKA < 175° or HKA > 185°, the unbalanced load distribution due to excessive abduction or adduction torque will bring the risk of component loosening), limb mechanical alignment correction can be applied to limit the overall mechanical alignment between 175° < HKA < 185° postoperatively;

[0386] · When the pre-arthritic knee joint line is considered mechanically unstable (the condyles are too inclined, if the postoperative FMA exceeds 5°, FMA < 85° or FMA > 95°, TMA < 85° or TMA > 95°, there is a risk of loosening due to unbalanced load distribution), condyle offset correction can be applied to limit the inclination angles of the condyles and the proximal tibia to 5° (85° < FMA, TMA < 95°). This also occurs when there is hypoplasia (poor development) of the medial or lateral condyle or excessive wear of the condyle bone;

[0387] · When the pre-arthritic limb mechanical alignment must be corrected, this means that the goal is a restricted or mixed mechanical alignment, and the postoperative limb mechanical alignment is an intermediate mechanical alignment, between the anatomically deviated mechanical alignment before arthritis and the postoperative neutral mechanical alignment (in this case, a compromise is made to the FMA (the inclination of the distal femoral joint line). This compromise must be moved backward / reported later to the condyle to balance the correction throughout the flexion process).

[0388] · When the pre-arthritic lateral trochlear eminence is too flat, this may lead to patellar instability (patellar dislocation) during flexion, so a side wall (at least 5 mm) will be constructed to fix the patella and correctly center the patella during flexion;

[0389] · When the pre-arthritic tibial slope is too large or insufficient (excessive downhill or uphill), this may lead to loss of movement or hyperextension (backward bending) accompanied by knee joint laxity, so correction must be systematically performed to make the posterior tibial slope fall within the range of 0° < TPS < 10°. <000098�>

[0390] Methods for making personalized prostheses

[0391] Now refer to Figures 24A to 24F The method 7000 of the present invention is not necessarily in the following order. The method 7000 of manufacturing a natural, personalized prosthesis includes at least one or all of the following steps:

[0392] - Step 7002: (a) measuring the 3DHKA mechanical alignment of the knee joint before surgery;

[0393] - Step 7004: (b) reconstructing the post-operative 3DHKA to the pre-arthritis HKA (if not an outlier);

[0394] - Step 7006: (c) defining the postoperative 3D HKA realignment as the corrected pre-arthritis HKA (if outlier);

[0395] - Step 7010: (d) measuring the preoperative anteroposterior dimension of the distal femur;

[0396] - Step 7012: (e) reproducing the correct AP prosthetic femoral dimensions, taking into account that the implant cannot rotate (or tilt or flex) more than 10° in the sagittal plane;

[0397] - Step 7014: (f) Measure the distal, posterior, and TMA (joint line) of the preoperative FMA;

[0398] - Step 7016: (g) reconstructing the postoperative FMA and TMA inclination to the pre-arthritis FMA and TMA inclination (if not abnormal), and reconstructing the pre-arthritis femoral torsion;

[0399] - Step 7020: (h) defining the postoperative FMA, TMA inclination as the corrected pre-arthritis FMA, TMA inclination (if outliers) and adjusting the femoral torsion according to the planning matrix, which is a matrix that takes anatomical input from landmarks in each of the three planes (it calculates preoperative dimensions and angles that define the morphological type and phenotype of the pathological condition) and outputs personalized postoperative parameter values ​​for defining two types of representations / sketches (dimensions, articular surfaces) of the limb realignment and knee joint shape;

[0400] - Step 7022: (i) measuring the preoperative TL inclination and trochlear depth;

[0401] - Step 7024: (j) defining which part of the final inclination must be achieved on the bone (direction of resection) and which part must be integrated into the implant (condylar offset) according to the rules described in the planning matrix;

[0402] - Step 7026: (k) Reconstruct the postoperative TL inclination to the pre-arthritic TL inclination (if not an outlier) and reconstruct the depth of the trochlea;

[0403] - Step 7030: (I) defining the postoperative TL inclination as the corrected pre-arthritic TL inclination (if abnormal) and recreating the trochlea depth by adding a lateral eminence to the trochlea;

[0404] - Step 7032: (m) reconstructing the postoperative condylar and trochlear JL curves into the pre-arthritis JL curves (if not outliers);

[0405] - Step 7034: (n) defining the postoperative condylar and trochlear joint line curves as the corrected pre-arthritic JL curves (if abnormal, by correcting the JL curve of the lateral condyle in case of hypoplasia or by correcting the JL curves of both condyles in case of sagittal deformity, such as recurvature or hyperflexion);

[0406] - Step 7036: (o) copy the postoperative condylar and trochlear mediolateral curves to the pre-arthritis ML (if not an outlier);

[0407] - Step 7040: (p) defining the postoperative condylar and trochlear ML curves as the corrected pre-arthritic ML curves (if abnormal, by correcting the ML curves of the lateral condyle or both condyles in case of sagittal deformity such as recurvature or hyperflexion);

[0408] - Step 7042: (q) measuring the distance from each condyle axis to the middle of the knee joint and reproducing the distance;

[0409] - Step 7044: (r) defining the outer limits (contours) of the bicondylar and trochlear articular surfaces to avoid oversizing or undersizing the prosthesis;

[0410] -Step 7046: (s) measuring the preoperative posterior tibial slope;

[0411] - Step 7050: (t) If abnormal, reconstruct the postoperative tibial posterior slope (TPS) to the corrected pre-arthritis TPS;

[0412] - Step 7052: (u) Define the rotation of the tibial component by measuring the angle to the anterior tibial tuberosity (TTA), which is the AP axis and is next to the axis (ML axis) passing through the centers of two circles describing the geometry of the medial and lateral surfaces of the tibia; next to 0

[0413] - Step 7054: (v) defining the AP and ML positions of the tibial intramedullary stem to obtain a well-centered tibial intramedullary stem on the tibial metaphysis and / or diaphysis;

[0414] - Step 7056: (w) defining the outer limits of the tibial component contour (to the tibial edge) to avoid oversizing the prosthesis (risking contact with surrounding soft tissue causing pain) or undersizing (risking subsidence requiring revision); and

[0415] -Step 7060: (x) Measure the distance between the distal femoral resection and the proximal tibial resection (extension gap) to account for the overall thickness of the implant. Figure 25A , according to the method 8000 of the present invention, not necessarily in the following order. The method 8000 describes different routines:

[0416] -Step 8002: (a) order generation;

[0417] - Step 8004: (b) image transmission;

[0418] - Step 8006: (c) image confirmation;

[0419] -Step 8010: (d) skeletal model creation;

[0420] - Step 8012: (e) 3D planning, optionally supported by a product database 8014 and / or CAO software 8016;

[0421] - Step 8020: (f) patient-specific cutting guide design, optionally supported by product database 8014 and / or CAO software 8016;

[0422] - Step 8022: (g), manufacturing;

[0423] - Step 8024: (h), delivering; and

[0424] -Step 8026: (i), surgery.

[0425] Now refer to Figure 25B , showing the Figure 25A Sketch / representation of the procedure for manufacturing the knee prosthesis of the present invention 8500

[0426] Now refer to Figures 26A to 26D , which describes the femoral component partitioning and parameterization in more detail. These figures show the medial anterior femoral-patellar compartment 2602, the lateral anterior femoral-patellar compartment 2604, the medial distal femoral-condylar compartment 2606, the lateral distal femoral-condylar compartment 2610, the medial posterior femoral-condylar compartment 2612, and the lateral posterior femoral-condylar compartment 2614.

[0427] As will be appreciated by those skilled in the art, the present invention may be embodied as a system, device, or method. In one aspect, the present invention is a computer-implemented method in which a program for performing specific tasks is encoded on a medium for selecting an appropriate knee prosthesis for a particular patient. The computer includes a CPU / processor, a memory, and input and output devices operatively interconnected thereto, which performs one or more of the method steps described herein.

[0428] Should be understood that, in all embodiments described herein, need select in many 3D knee joint prostheses, parameterized model for each component of knee joint prosthesis (femoral component, tibial component, tibial pad, patellar component) from sketch / representation construction, so that generate and represent all shape configurations substantially of normal knee joint global anatomical variability.Parameterized model is divided into compartment (for femoral component, for example medial distal condylar compartment, medial posterior condylar compartment, lateral distal condylar compartment, lateral posterior condylar compartment, medial trochanter compartment, lateral trochanter compartment). In each of these independent compartments, all defined sketch / representation to reproduce the shape and size of the corresponding part of knee joint surface and prosthesis profile. These sketches / representation are defined in each plane (coronal, sagittal and cross section), and can copy the shape and size of knee joint prosthesis, knee joint in each plane. Fixed value and parameterized value (mathematical function) define each in these sketches / representation. The parameterized values ​​are dynamically linked to a calculation table that defines the relationships between each individual compartment and describes the 3D variability of each compartment. Each prosthetic component configuration (shape and size) generated from the parametric model and calculation table replicates the anatomical variability of the normal knee.

[0429] It should also be understood that in each sub-step of the method for selecting a 3D knee prosthesis model described herein, a planning algorithm is used that is able to select a unique (unique) patient-specific component configuration for each patient from this vast series of prosthesis configurations stored in the database, wherein the shape and size of the prosthesis best matches the knee joint motion of the patient before arthritis. In the first step, anatomical landmarks are identified in the hip, knee, and ankle joints (also including the upper body) to determine the patient's diseased leg and knee joint morphology and phenotype. In the second step, the 3D planning algorithm (a specific matrix for each plane) determines the specific corrections made to the leg mechanical alignment and the diseased knee joint shape to replicate the pre-arthritic knee joint mechanical alignment and knee joint shape. Please note that normality in knee prosthesis selection (+ / - 2 standard deviations for each parameter average) can basically always be achieved using these inputs, but outliers are not allowed and abnormal (the average value for at least one parameter exceeds 2 standard deviations) prosthesis shapes will not be produced. In the third step, the algorithm will select a unique and patient-specific prosthetic knee size among all knee configurations and resurface and replicate the pre-arthritic knee (shape and size) by positioning the components directly in the correct 3D orientation and mechanical alignment.

[0430] In another embodiment, a non-transitory information storage medium is provided having encoded thereon a knee prosthesis characterization and selection program. When the program is executed, it performs a method that instructs a processor to assist a user in selecting a 3D knee prosthesis model for a particular patient. The method encoded thereon comprises the following steps: (a) parameterizing a knee prosthesis according to well-defined and independent knee compartments using a parameterization module;

[0431] (b) generating a large number of knee joint shapes in the form of 3D knee prosthesis models using a model generator, wherein these models reproduce the 3D shape asymmetry of a large number of individual knee joint samples and storing them in a database, thereby being able to well replicate the knee joint motion of substantially any patient by generating shapes that vary at least one compartment shape parameter (surface and dimension), and storing these 3D knee prosthesis models associated with the shape parameters and asymmetry of each model in the database, so that the asymmetry of the patient's knee joint can be compared with the asymmetry of the 3D knee prosthesis models,

[0432] (c) After studying the patient's pathology and developing criteria for a pre-lesional knee prosthesis that meets the patient's needs, a search module is utilized to search the database, comparing a large number of knee shapes based on the best match for each model's asymmetry to identify candidate matches:

[0433] (d) displaying candidate matches and their attributes on an output device;

[0434] (e) providing a method for selecting the best match among the determined suitable candidate matches;

[0435] (f) If the selected knee prosthesis is not in stock, you can choose to generate a production order.

[0436] Artificial intelligence, including but not limited to neural networks and / or machine learning algorithms, can be used in any step of the processing involved in this application to facilitate analysis of the patient's current anatomical structure, calculate the patient's most likely pre-lesion anatomical structure, to help select a suitable prosthesis in a database (e.g., applying pattern recognition and classification algorithms) and / or to help design a specific prosthesis for the patient.

[0437] Additionally, the system contemplates the use, sale, and / or distribution of any goods, services, or information similar to the functionality described herein.

[0438] The specification and drawings should be considered in an illustrative manner and not in a restrictive manner, and all modifications described herein are intended to be included within the scope of the invention as claimed. Therefore, the scope of the invention should be determined according to the appended claims (whether currently existing or later amended or added, and their legal equivalents), and not solely by the examples described above. The steps recited in any method or process claim may be performed in any order unless otherwise expressly stated, and are not limited to the specific order set forth in any claim. In addition, the elements and / or components recited in the device claims may be assembled or otherwise functionally configured in various permutations and combinations to produce substantially the same results as the present invention. Therefore, the present invention should not be interpreted as being limited to the specific configurations recited in the claims.

[0439] The benefits, other advantages, and techniques mentioned herein should not be construed as critical, required, or essential features or elements of any or all the claims.

[0440] As used herein, the terms "comprises," "comprising," or variations thereof, are intended to refer to a non-exclusive list of elements such that any apparatus, process, method, article, or composition of the invention that includes a list of elements may include not only those recited elements but also other elements, such as those described in this specification. Unless expressly stated otherwise, the use of the terms "comprises," "comprising," or "containing," or "consisting essentially of," is not intended to limit the scope of the invention to the elements listed thereafter, unless otherwise stated. Other combinations and / or modifications of the above-described elements, materials, or structures used in the practice of the invention may be changed or modified into other designs by those skilled in the art without departing from the general principles of the invention.

[0441] Unless otherwise stated, the above patents and articles are hereby incorporated by reference into the present disclosure to the extent they are not inconsistent with the present disclosure.

[0442] Further features and embodiments of the invention are described in the dependent claims.

[0443] Furthermore, the invention should be considered to include all possible combinations of each and every feature described in this specification, the appended claims and / or the drawings which may be considered novel, inventive and industrially applicable.

[0444] The present invention can be characterized by the following set of features:

[0445] 1. A method for selecting a 3D knee prosthesis model for a specific patient, the method comprising:

[0446] (a) parameterize the knee prosthesis according to well-defined and independent knee compartments,

[0447] (b) generating a large number of knee joint shapes in the form of 3D knee prosthesis models, which reproduce the asymmetry of the 3D shape of each individual knee joint, thereby being able to reproduce the knee joint motion of substantially any patient by generating shapes that vary the shape parameters (surface and dimensions) of at least one of these compartments, and storing these 3D knee prosthesis models associated with the shape parameters and asymmetry of each model in a database, thereby being able to compare the asymmetry of the patient's knee joint with the asymmetry of the 3D knee prosthesis models, and

[0448] (c) Study the patient's pathology and develop a standard pre-pathological knee prosthesis that meets the patient's needs,

[0449] Based on the optimal matching of the asymmetry of each model, the appropriate knee prosthesis that best meets the patient's needs can be selected from a large number of knee joint shapes, and the selected shape best meets the patient's criteria.

[0450] 2. The method according to feature set 1, comprising the further step of optionally using a planning algorithm to select a suitable knee prosthesis from a large number of knee joint shapes based on the best match of the asymmetry of each model, selecting the shape that best meets the patient's criteria.

[0451] 3. The method according to the above feature set, wherein the selected 3D knee prosthesis model is used to produce a suitable prosthesis for the patient.

[0452] 4. The method according to the above feature set, wherein the produced prosthesis can be used by a surgeon for implantation.

[0453] 5. A method according to feature set 1, wherein the design specifications of the present invention regarding the distal and posterior condylar to trochlear portions of the femoral component are used to personalize features that, when put together, realign the affected limb to its pre-lesion appearance and resurface the joint surface to approximate the pre-arthritic knee shape and size as closely as possible.

[0454] 6. A method for preparing a 3D knee prosthesis model database from which a 3D knee prosthesis model matching a specific patient's needs can be selected, the method comprising the following steps:

[0455] (a) Parameterizing the selected knee prosthesis design configuration into features corresponding to well-defined and independent knee compartments;

[0456] (b) generating a large number of 3D knee prosthesis models corresponding to at least one compartment by varying shape parameters (e.g., surface and size), and which reproduce the 3D shape asymmetry of a single knee sample population; and

[0457] (c) populating the database with the generated models, thereby generating a 3D knee prosthesis model database with high variability;

[0458] (d) Using 3D scanning to study the movement of the patient's knee joint;

[0459] (e) adjusting for the lesion and optionally adjusting for soft tissue effects to create a hypothetical pre-lesion patient knee kinematic model;

[0460] (f) optionally using a planning algorithm, selecting one or more models from the obtained inventory of knee prostheses or from a database of 3D knee prosthesis models that best replicate a hypothetical pre-lesion model or a knee kinematic model defined by the 3D shape asymmetry of the patient's knee;

[0461] (g) if there is no matching knee prosthesis in the inventory, fabricating a model of the selected prosthesis; and

[0462] (h) making the prosthesis available for implantation.

[0463] 7. A knee joint prosthesis is provided, the knee joint prosthesis being manufactured from a 3D model selected by applying a method comprising the following steps:

[0464] (a) Analyze the patient's current and pre-lesion knee joint motion behavior and the patient's HKA mechanical alignment,

[0465] (b) optionally using a planning algorithm, selecting an appropriate 3D model from a comprehensive database of 3D models of various knee morphologies, each 3D model being adapted to the known morphology and production constraints and requirements, and

[0466] (c) Fabrication of the selected 3D model representing a producible and essentially customized knee prosthesis adapted to the individual patient's 3D anatomy, thereby recreating a natural-like knee joint.

[0467] 8. The method according to the present invention comprises the following steps:

[0468] (a) Measuring the patient's preoperative condition using CT scan, X-ray, MRI, EOS (under weight-bearing or non-weight-bearing conditions, single-foot, double-foot, varus / valgus stress), or any other measuring device and / or any method known in the art, including at least:

[0469] (i) HKA mechanics alignment,

[0470] (ii) relative motion of the femur to the tibia (combined sliding and rolling motion),

[0471] (iii) femoral and tibial contact surfaces and bone shape, and

[0472] (iv) patellar shape and position relative to the femur and tibia, and the patellar-femoral contact surface;

[0473] (b) define target postoperative HKA alignment based on (ai) and the patient's anatomical history (if known);

[0474] (c) Define the target postoperative relative motion of the femur to the tibia (combined sliding and rolling motion) according to (b) and (aii);

[0475] (d) define the shapes of the contact surfaces of the femoral and tibial components according to (b), (c), and (aiii);

[0476] (e) define the shape of the femoral and tibial prosthetic connections according to (d) and (aiii);

[0477] (f) Determine the target postoperative patellar position relative to the femoral component and relative to the tibial component based on (b), (c), (d), (aiv), and the patient's anatomical history (if known);

[0478] (g) define the interface shape between the femoral prosthesis and the patella according to (b), (c), (d), (f), and (aiv) (only the interface between the femoral component and the patellar component, not the interface between the patellar component and the tibial component); and

[0479] (h) Combining all of the above definitions into an individually adapted knee prosthesis.

[0480] 9. The method of any one of feature sets 1 to 4, wherein the 3D scan is a video scan of the patient's knee joint motion.

[0481] 10. A method according to one of feature sets 1 to 4, wherein the known joint compartments include at least one of the following compartments: an extension compartment, a flexion compartment; a medial compartment; a lateral compartment; a femoro-tibial compartment; and a femoro-patellar compartment.

[0482] 11. The method according to one of feature sets 1 to 4, wherein the method comprises taking the articulation of the patella into account when selecting a suitable 3D model.

[0483] 12. A prosthesis manufactured according to the method of any one of the feature sets 1 to 4.

[0484] 13. A method according to one of feature sets 1 to 4, wherein the knee prosthesis of the present invention is suitable for conditions of femoral varus, such that the distal lateral condyle of the femoral prosthesis (1110) is shorter than the distal medial condyle, thereby creating an offset (1172) between the condyles, and the same offset (1172) is reproduced in the tibial pad (1160).

[0485] 14. A method according to one of feature sets 1 to 4, wherein the knee prosthesis of the present invention is suitable for use in cases of femoral valgus, in which case the distal lateral condyle of the femoral prosthesis (1110) is longer than the distal medial condyle, thereby creating an offset (1174) between the condyles, and the same offset (1174) is reproduced in the tibial pad component (1160).

[0486] 15. The method according to any one of feature sets 1 to 4, wherein the knee prosthesis of the present invention is suitable for femoral varus, wherein the femoral prosthesis (1110) has an angle (1182) that flares from the distal lateral condyle to the distal medial condyle, and the same angle (1182) is reproduced in the tibial pad (1160).

[0487] 16. A method according to one of feature sets 1 to 4, wherein the knee prosthesis of the present invention is suitable for cases of femoral valgus, wherein the femoral prosthesis (1110) has an angle (1184) that opens from the distal medial condyle to the distal lateral condyle, and the same angle (1184) is reproduced in the tibial pad (1160).

[0488] 17. The method according to any one of feature sets 1 to 4, wherein the knee prosthesis of the present invention has an offset (1172, 1174) ranging from 0 to 10 mm and an angle (1182, 1184) ranging from 0° to 15°.

[0489] 18. The method of one of feature sets 1 to 4, wherein when determining the size of the prosthesis, the shape radius (962) of the medial condyle surface in the coronal plane and the transverse plane, the shape radius (963) of the trochlear surface in the coronal plane and the shape radius (964) of the lateral condyle surface in the coronal plane and the transverse plane can be adjusted independently of each other and are independent of the prosthesis size and the patient's hip-knee-ankle (HKA) mechanical alignment, whether normal, varus or valgus.

[0490] 19. The method according to any one of the feature sets 1 to 4, wherein the contour (external dimensions of the prosthesis) is adjusted to not be too large, or too small to expose the resected area to be resurfaced.

[0491] 20. A method according to one of feature sets 1 to 4, wherein the contour angles (982, 984, 992, 994) of the anterior and posterior surfaces of the femoral prosthesis are adjusted independently of each other and are independent of the prosthesis size and the patient's hip-knee-ankle (HKA) mechanical alignment, whether normal, varus or valgus.

[0492] 21. A method according to one of feature sets 1 to 4, wherein the contour angles (982, 984, 992, 994) of the anterior and posterior surfaces of the femoral prosthesis vary between 0° and 50° to obtain the desired knee kinematics and fit the patient's size.

[0493] 22. A method according to one of feature sets 1 to 4, wherein the shape of the medial condyle surface in the sagittal plane (medial condyle J-curve) (972), the shape of the trochlear surface in the sagittal plane (trochlear J-curve) (973) and the shape of the lateral condyle surface in the sagittal plane (lateral condyle J-curve) (974) can be adjusted independently of each other and are independent of the prosthesis size and the patient's hip-knee-ankle (HKA) mechanical alignment, whether normal, varus or valgus.

[0494] 23. A method according to one of feature sets 1 to 4, wherein the shape of the medial condyle surface in the sagittal plane (medial condyle J curve) (972), the shape of the trochlear surface in the sagittal plane (trochlear J-curve) (973) and the shape of the lateral condyle surface in the sagittal plane (lateral condyle J curve) (974) can be made by one radius, but can also be made by a combination of two or more radii, whose sizes can vary from 15 mm to 65 mm.

[0495] 24. The method according to any of the above feature sets, wherein the combination of radii is achieved by using spline curves or any other suitable curves to smoothly transition from one radius to the next.

[0496] 25. A method according to any one of the above feature sets, wherein the femoral portion of the knee prosthesis of the present invention is suitable for any bone resection selected from one of the following groups: including plane resection, oblique resection, curved resection, offset resection and double oblique resection suitable for the individual needs of the patient.

[0497] 26. The method according to the above feature set, wherein the bone resection is sawn or ground to suit the individual needs of the patient.

[0498] 27. A method for producing a natural, personalized implant comprising at least one or all of the following steps:

[0499] (a) Measurement of the 3D HKA mechanical alignment of the knee joint before surgery;

[0500] (b) The postoperative 3D HKA was reassembled to replicate the pre-arthritis HKA (if not an outlier);

[0501] (c) postoperative 3D HKA recombined to be defined as the corrected pre-arthritis HKA (if abnormal);

[0502] (d) Measure the anteroposterior dimension of the distal femur before surgery;

[0503] (e) Replicate the correct AP prosthetic femoral dimensions, taking into account that the implant cannot rotate (or tilt or flex) more than 10° in the sagittal plane;

[0504] (f) Preoperative FMA distal, posterior, and TMA (joint line) measurements;

[0505] (g) The postoperative FMA and TMA inclinations were restored to those before arthritis (if they were not abnormal values) and the femoral torsion before arthritis was restored;

[0506] (h) Postoperative FMA and TMA inclination were defined as the corrected pre-arthritis FMA and TMA inclination (if abnormal), and femoral torsion was adjusted according to the planning matrix;

[0507] (i) Measure the preoperative TL inclination and trochlear depth;

[0508] (j) Following the rules described in the planning matrix, define which part of the final inclination must be achieved on the bone (direction of resection) and which part must be integrated into the implant (condylar offset);

[0509] (k) Reproduce the postoperative TL inclination to the pre-arthritis TL inclination (if not an abnormal value) and reproduce the depth of the trochlea;

[0510] (I) The postoperative TL inclination was defined as the corrected pre-arthritis TL inclination (if abnormal), and the trochlear depth was reproduced by adding a lateral eminence to the trochlea;

[0511] (m) Reproduction of the postoperative condylar and trochlear JL curves to the pre-arthritis JL curves (if not outliers);

[0512] (n) The postoperative condylar and trochlear joint line curves were defined as the corrected prearthritic JL curve (if abnormal, the JL curve of the lateral condyle was corrected in the case of hypoplasia, or the JL curves of both condyles were corrected in the case of sagittal deformity, such as recurvature or flexion);

[0513] (o) Reproduction of the postoperative condylar and trochlear mediolateral curves to the prearthritic ML (if not an outlier);

[0514] (p) The postoperative condylar and trochlear ML curves were defined as the corrected pre-arthritic ML curves (if abnormal, the ML curves of the lateral condyle or both condyles were corrected in the case of sagittal deformity such as recurvature or hyperflexion);

[0515] (q) Measure the distance from each condyle axis to the middle of the knee joint and reproduce the distance;

[0516] (r) define the outer limits (contours) of the condylar and trochlear articular surfaces to avoid oversizing or undersizing the prosthesis;

[0517] (s) Measure the preoperative posterior tibial slope;

[0518] (t) If abnormal, the postoperative tibial posterior slope (TPS) was reproduced to the corrected pre-arthritis TPS;

[0519] (u) The rotation of the tibial component is defined by measuring the angle to the anterior tibial tuberosity (TTA), which is the AP axis and the axis passing through the centers of two circles describing the geometry of the medial and lateral tibial surfaces (ML axis); 0

[0520] (v) define the AP and ML positions of the tibial stem to obtain a well-centered tibial stem on the tibial metaphysis and / or diaphysis;

[0521] (w) define the outer limits of the tibial component contour (to the tibial edge) to avoid oversizing the prosthesis (risking contact with surrounding soft tissue causing pain) or undersizing (risking subsidence requiring revision); and

[0522] (x) Measure the distance between the distal femoral resection and the proximal tibial resection (extension gap) to account for the overall thickness of the implant.

[0523] 28. A prosthesis manufactured according to one of feature sets 1 to 4, wherein the prosthetic components of the invention: the tibial pad, the tibial tray and the tibial intramedullary stem, are each composed of one or more parts and are assembled before or during surgery.

[0524] 29. The prosthesis according to the above feature set, wherein at least one of the components comprises: (a) an element selected from the group consisting of:

[0525] (i) The articular surface of the tibial pad, including the surface corresponding to the medial condyle (1262)

[0526] (ii) the surface corresponding to the pulley (1263), and

[0527] (iii) the surface corresponding to the lateral condyle (1264),

[0528] (b) the bone-facing surface (1230) of the tibial tray, and

[0529] (c) Tibial intramedullary stem portion (1240).

[0530] 30. The prosthesis according to the preceding set of features, wherein any desired orientation angle, offset, or any combination thereof can be applied to the tibial pad, tibial tray, and tibial intramedullary stem to best suit the needs of an individual patient.

[0531] 31. The prosthesis according to any of the above two feature sets, wherein the tibial pad, tibial tray and tibial intramedullary stem can each be composed of one or more components.

[0532] 32. The prosthesis of any of the above feature sets, wherein the tibial intramedullary stem (1240) is not orthogonal to the bone-facing surface (1230), but is oriented at a selected angle (1242) to suit the needs of an individual patient.

[0533] 33. A prosthesis according to any of the above feature sets, wherein the tibial intramedullary stem (1240) is not orthogonal to the bone-facing surface (1230), but is oriented at an angle (1242), and the bone-facing surface (1230) is oriented at a certain angle (1232) to suit the needs of an individual patient.

[0534] 34. The prosthesis according to the above set of features, wherein the thickness of the medial pad is made very thin to facilitate the orientation of the knee joint when in varus.

[0535] 35. A prosthesis according to any of the above feature sets, wherein the tibial intramedullary stem (1240) is not orthogonal to the bone-facing surface (1230), but is oriented at a selected angle (1242), the bone-facing surface (1230) is oriented at another selected angle (1232), and the corresponding surface (1264) of the lateral condyle is offset (1265) to accommodate the needs of individual patients.

[0536] 36. A prosthesis according to any of the above feature sets, wherein the tibial intramedullary stem (1240) is not orthogonal to the bone-facing surface (1230), but is oriented at a selected angle (1242), the bone-facing surface (1230) is oriented at a second selected angle (1232), and the medial and lateral condyle distal tangents (1266) are oriented at a third selected angle (1267) to accommodate the needs of individual patients.

[0537] 37. The prosthesis of any of the above feature sets, wherein the offset (1265) can vary from 0 to 10 mm and the orientation angle (1232, 1242, 1267) can vary up to 12°.

[0538] 38. The prosthesis of the aforementioned set of features wherein the offset can vary from -10° to +10° in the mediolateral or anteroposterior dimension and can be oriented up to 12° about the longitudinal axis of the tibial intramedullary stem.

[0539] 39. A prosthesis according to any of the above feature sets, wherein the sagittal J curve (1310) is adjusted to cooperate with the corresponding surface of the femoral prosthesis of the present invention so that the function of the knee prosthesis of the present invention is tailored to the needs of individual patients.

[0540] 40. The prosthesis of the preceding feature set, wherein the sagittal J-curve (1310) is substantially a single radius.

[0541] 41. The prosthesis of the penultimate feature set, wherein the sagittal J-curve (1310) is substantially a combination of two or more radii (1312, 1313, 1314, 1315) having dimensions falling within the range of from 15 mm to 80 mm.

[0542] 42. A prosthesis according to any one of the above feature sets, wherein, in order to fit the tibia of an individual patient, in the sagittal plane, the tibial intramedullary stem (1340) of the tibial component (1300) of the knee prosthesis of the present invention is placed in the center of the tibial component (1300) and optionally presents an offset (1342) toward the anterior tibia or toward the posterior tibia.

[0543] 43. The prosthesis according to the above feature set, wherein the offset (1342) can vary from 0 to 10 mm.

[0544] 44. The prosthesis of the penultimate feature set wherein the offset varies from -10° to +10° in the mediolateral or anteroposterior dimension and is oriented up to 12° about the longitudinal axis of the tibial intramedullary stem.

[0545] 45. A prosthesis according to the above set of features, wherein, for the same purpose of fitting with the tibia of an individual patient, in the sagittal plane, the bone-facing surface (1332) of the tibial component (1300) of the knee prosthesis of the present invention can be oriented at a selected angle (1344) that can vary by up to 12°.

[0546] 46. ​​A prosthesis according to any of the above feature sets, wherein the articular surfaces of the patellar components (1862, 1863, 1864) are configured to mate with corresponding surfaces on the femoral components (1852, 1853, 1854), also taking into account the patient's hip-knee-ankle (HKA) mechanical alignment, whether normal, varus or valgus.

[0547] 47. The prosthesis of any of the preceding feature sets, wherein where the femoral component has an offset (1872, 1874) between the distal lateral condyle and the distal medial condyle, the offset (1872, 1874) is replicated in the patellar component.

[0548] 48. The prosthesis according to the above feature set, wherein the patellar component of the knee prosthesis of the present invention can have a mediolateral surface that is symmetrical or asymmetrical between the medial and lateral compartments, and an anterior-posterior surface that is symmetrical or asymmetrical between the anterior and posterior compartments, optionally selected using a planning algorithm to match the needs of an individual patient.

[0549] 49. A prosthesis according to any of the above feature sets, wherein each of the medial, lateral, anterior, and posterior compartments is specified to fall within the range of from 8 mm to 30 mm in width and height, these values ​​being independent of patellar thickness, which should be at least 6 mm or greater.

[0550] 50. A method according to any one of the above feature sets, wherein curve / surface fitting and smoothing techniques are applied between shapes that interact across adjacent bony compartments in order to fuse the prosthetic elements corresponding to the bony compartments to produce a composite knee prosthesis suitable for the patient's needs.

[0551] 51. A partial or full knee prosthesis designed according to the anatomy of the individual patient, recreating a natural knee joint, wherein its geometry is determined by independently changing the following parts: the medial femoro-tibial joint to the lateral femoro-tibial joint and then to the femoro-patellar joint.

[0552] 52. A method for producing a partial or full knee prosthesis adapted to the anatomy of an individual patient, the method comprising considering the patient's current and pre-lesion knee motion behavior, and further considering his individual hip-knee-ankle (HKA) mechanical alignment, and using these inputs to recreate a natural-like knee model, and also using this recreated natural knee model rather than a diseased knee model to create a prosthesis that recreates this natural knee joint.

[0553] 53. A femoral prosthesis for implantation into the femur of a patient's knee joint, comprising:

[0554] o two condylar portions, including two condylar portions comprising a medial condyle and a lateral condyle, having a bone-facing surface for abutting at least a portion of each condyle of a patient's knee joint, and an articular surface generally opposite each bone-facing surface; each articular surface having a curvature (J-curve) generally lying in a first plane (sagittal plane) and an ML curve generally lying in second and third planes (frontal plane of the distal condyle and cross-section of the posterior condyle); each articular surface of the medial condyle and the lateral condyle may have a condylar offset in the second and third planes, which may or may not be equal;

[0555] o a trochlear portion, including a trochlear depth and medial and lateral trochlear eminences, having a bone-facing surface for abutting at least a portion of the trochlea of ​​the patient's knee, and an articular surface generally opposite the bone-facing surface; each articular surface having a curvature (J-curve) generally lying in a first plane (sagittal plane) and an ML curve generally lying in second and third planes (frontal and transverse planes); each articular surface of the medial and lateral eminences can have an offset and depth relative to the trochlea in the second and third planes, which can be equal or unequal;

[0556] o the orientation of the distal and posterior condylar portions of the articular surface of the trochlear portion to the distal and posterior condyles is independent and may be oriented parallel or obliquely (converging or diverging) in at least one plane;

[0557] oML condylar offset can be integrated between the medial and lateral articular surfaces of the distal condylar part (= distal condylar offset) and the posterior condylar part (= posterior condylar offset) of the distal condyle and posterior condyle, the condylar offset being the same or different between the distal condylar and posterior condylar parts;

[0558] oML trochlear offset can be integrated between the medial and lateral articular surfaces of the medial and lateral trochlear eminences, with the trochlear offset being the same as or different from the condylar offset of the distal and posterior condyles.

[0559] 54. A prosthesis according to the above set of features, wherein the sagittal J-curve of at least one articular surface from the distal condyle and posterior condyle (medial, lateral) or trochlea (eminence, trochlear depth) is defined by a single, double or multiple radius or matched to a patient-specific J-curve.

[0560] 55. A prosthesis according to one of the above two feature sets, wherein the sagittal J-curve of at least one of the medial and lateral articular surfaces from the distal and posterior condyles is positioned at a fixed or variable distance from the trochlear J-curve (medial and / or lateral eminence, trochlear depth), symmetrically or asymmetrically.

[0561] 56. A prosthesis according to any of feature sets 51 or 52, wherein the sagittal J-curve of at least one articular surface from the distal and posterior condyle (medial, lateral = narrowed angle) or trochlea (medial and / or lateral eminence, trochlea depth = groove axis in the frontal plane, Whiteside's line in the axial plane) is oriented parallel or obliquely in at least one plane, primarily the frontal and axial planes.

[0562] 57. A prosthesis according to feature sets 51 to 54, wherein the articular geometry and dimensions of at least one joint-facing surface of the condylar portion and / or trochlear portion correspond to (or closely match, or closely fit) the dimensions (including at least AP dimensions), shape (including at least condylar and trochlear offset, J curve and ML curve) and profile (including at least AP / ML, size, narrowing angle, trochlear height, posterior condyle height) of the patient's knee joint surface.

[0563] 58. A prosthesis according to feature sets 51 to 55, wherein the tangents connecting the most distal points of the medial and lateral surfaces of the distal end, or the tangents connecting the most posterior points of the medial and lateral surfaces of the posterior condyle, or the tangents connecting the most anterior points of the medial and lateral surfaces of the trochlear portion are parallel or inclined to each other.

[0564] 59. A prosthesis according to any one of the above prosthesis feature sets, wherein the bone-facing surface is defined by a single straight flat or inclined surface, or by two staggered (offset) flat or inclined surfaces, or by staggered (offset) curved surfaces.

[0565] 60. The prosthesis of any preceding set of prosthesis features, wherein the bone-facing surface is fixable to the bone by adhesive fixation or adhesive-free fixation.

[0566] 61. Prosthesis according to any of the above-mentioned prosthesis feature sets, wherein the prosthesis corresponds to different systems (PS: posterior stabilized, UC: ultra congruent, PCR: posterior cruciate retention, BCR: double cruciate retention), for mobile insertion or fixed insertion, for primary or revision knee joint (semi-constrained or constrained, hinged), for cement fixation or non-cemented or any other type of fixation, for monolithic or modular components, for each material (titanium, chrome cobalt, ceramic...)

[0567] 62. A method for manufacturing a knee joint prosthesis using a 3D model selected after applying the method, the method comprising:

[0568] (a) Analyze the patient's current and pre-lesion knee joint motion behavior and the patient's HKA mechanical alignment.

[0569] (b) optionally using a planning algorithm, selecting an appropriate 3D model from a comprehensive database of 3D models of various knee morphologies, each 3D model being adapted for the known morphology and production constraints and requirements,

[0570] (c) Fabrication of a selected 3D model representing a producible and essentially customized knee prosthesis adapted to the individual patient's 3D anatomy, thereby recreating a natural-like knee joint.

[0571] 63. A non-transitory information storage medium having a knee prosthesis characterization and selection program, the program instructing a processor to implement any of the above methods so as to receive input and generate output.

[0572] 64. A non-transitory information storage medium having encoded thereon a knee prosthesis characterization and selection program, which, when executed, implements a method that instructs a processor to perform steps for assisting a user in selecting a 3D knee prosthesis model for a particular patient, the method comprising the steps of:

[0573] (a) parameterize the knee prosthesis according to well-defined and independent knee compartments,

[0574] (b) generating a large number of knee joint shapes in the form of 3D knee prosthesis models that reproduce the asymmetry of the 3D shapes of a large number of individual knee joint specimens, including generating models that replicate the motion of the knee joint of substantially any patient by varying the shape parameters (surface and dimensions) of at least one compartment, and storing these 3D knee prosthesis models in a database with the shape parameters and asymmetry associated with each model, thereby allowing the asymmetry of the patient's knee joint to be compared with the asymmetry of the 3D knee prosthesis models, and

[0575] (c) After studying the patient's pathology and developing criteria for a pre-lesional knee prosthesis that meets the patient's needs, optionally utilizing a planning algorithm, searching a database to compare a large number of knee shapes based on the best match for each model asymmetry to identify candidate matches:

[0576] (d) displaying candidate matches and their attributes on an output device;

[0577] (e) providing a method for selecting the best match among the identified suitable candidate matches;

[0578] (f) If the selected knee prosthesis is not in stock, a production order may optionally be generated.

[0579] 65. The medium of the above feature set, wherein the processor is a computer processor coupled to a memory, the processor being responsive to the program to access a database storing 3D knee prosthesis models or inventory knee prostheses.

[0580] 66. The medium of the preceding feature set, wherein the processor responds to input and output communicated with a user via the program.

[0581] Additional features and functions of the present invention are described in the claims and / or abstract accompanying this specification. Such claims and / or abstract are hereby incorporated by reference in their entirety into this specification and should be considered a part of this filed application.

[0582] There are many variations and modifications possible in the embodiments of the invention described herein. Although certain exemplary embodiments of the invention have been shown and described herein, a wide range of variations, modifications, and substitutions are contemplated in the foregoing disclosure. Although the foregoing description contains many specific details, these should not be construed as limitations on the scope of the invention, but rather as exemplifications of one or another preferred embodiment thereof. In some cases, certain features of the invention may be employed without the corresponding use of other features. It is appropriate, therefore, that the foregoing description be broadly interpreted and understood as being illustrative only, with the spirit and scope of the invention being limited only by the claims ultimately issued in this application.

[0583] appendix

[0584] definition

[0585] Definition of anatomical points of the knee joint

[0586] Definition of knee joint center

[0587] Definition of average knee flexion axis

[0588] Definition of knee joint mechanical alignment

[0589] Coronal or frontal plane

[0590] Axial plane or cross section

[0591] observe

[0592] Comparison with standard (off-the-shelf) knee prostheses and limitations of this knee prosthesis system

[0593] Description of knee prosthesis

[0594] Description of the Invention

[0595] The difference between STD (off-the-shelf) prostheses and our personalized knee prostheses:

[0596] Definition of anatomical points of the knee joint:

[0597] FHC(332): Femoral Head Center

[0598] KC(330): Knee Center

[0599] TC(334): Center of talus (not shown)

[0600] ME(342): medial epicondyle

[0601] LE(344): lateral epicondyle

[0602] MDC(352): distal medial condyle

[0603] LDC(354): distal lateral condyle

[0604] MPC(362): medial posterior condyle

[0605] LPC(364): Lateral posterior condyle

[0606] TGH(372): High trochlear groove

[0607] TGL(374): Low pulley groove

[0608] LT(384): lateral trochlear eminence

[0609] MT(382): medial trochlear eminence

[0610] Definition of Knee Center:

[0611] KC(330): Top of the intercondylar notch

[0612] TSE (3_): top of the tibial eminence (not shown)

[0613] MTEA(3_): Middle of TEA(346)

[0614] Definition of mean knee flexion axis:

[0615] TEAs(3464): surgical transepicondylar axis (top of LE(344) to groove of ME(342))

[0616] TEAc(3462): clinical transepicondylar axis (top of LE(344) to top of ME(342)) CA: cylindrical axis (center of the two spheres connecting the posterior condyle)

[0617] EFA: Extended face axis (connecting the centers of the distal radii of the two condyles)

[0618] FFA: flexion plane axis (connecting the centers of the posterior radius of the two condyles)

[0619] FHA: Femoral helical axis (combines flexion axis and axial rotation)

[0620] With the help of a four-bar linkage, the average flexion axis of the knee joint can also be located at the intersection of the two cruciate ligaments or at the intersection of the cruciate ligament and the collateral ligament in the sagittal plane.

[0621] Through kinematic alignment, the BCD and BCP are the instantaneous knee flexion axis.

[0622] Definition of knee joint mechanical alignment:

[0623] HKA: Mechanical axis of the limb (= load-bearing axis)

[0624] Connect two lines, the first between FHC to KC and the second between KC and TC,

[0625] If the angle between these two lines is 0 (HKA 180°), the mechanical alignment is neutral.

[0626] If the angle between the two lines is > 0 (HKA > 180°), the mechanical alignment is everted.

[0627] If the angle between the two lines is < 0 (HKA < 180°), the mechanical alignment is inversion.

[0628] Coronal or frontal plane:

[0629] FAA (326): Femoral anatomical axis (connects KC (330) to the mid-diaphysis)

[0630] FMA(336): Femoral Mechanical Axis (connects FHC(332) to KC(330))

[0631] HKS(338): Angle between FAA(326) and FMA(336)

[0632] Range between 1° and 10°

[0633] BCD (356): Distal tangent of the medial and lateral condyles (connecting the LDC (354) to the MDC (352))

[0634] Alpha (α, 358): the angle between FMA (336) and BCD (356)

[0635] Also known as FMA: Femoral Mechanical Axis Angle (although there may be a risk of confusion between FMA = Femoral Mechanical Axis (336) and FMA = Femoral Mechanical Axis Angle for the unskilled reader, the skilled person will know the difference from the context)

[0636] Also called midplane: The distal femoral mechanical axis angle can be orthogonal or non-orthogonal to the FMA (336)

[0637] Range is between 82° and 105°

[0638] TEA(346): transepicondylar axis or biepicondylar axis

[0639] Connect ME (342) to LE (344)

[0640] TEA(3464): surgical transepicondylar axis

[0641] TEAc(3462): Clinical transepicondylar axis

[0642] = intersection of the two collateral ligaments

[0643] Can be parallel or non-parallel to BCD(356)

[0644] Can be orthogonal or non-orthogonal to FMA (336)

[0645] DCA(358): distal condylar angle

[0646] Angle between TEA(346) and BCD(356)

[0647] Range is between -5° and 10°

[0648] SA (376): Groove axis (connects KC (330) to TGH (372))

[0649] SA can be between FMA (336) and FAA (326) or outside their range

[0650] May be orthogonal or non-orthogonal to TEA (346) and / or BCD (356)

[0651] Axial plane or cross section:

[0652] TL(386): Pulley line, connecting LT(382) to MT(384)

[0653] TEA (346): Trans-epicondylar axis or bi-epicondylar axis, connecting ME (342) to LE (344)

[0654] BCP (366): tangent line to the posterior end of the medial and lateral condyles (connecting LPC (364) to MPC (362))

[0655] PCA(368): posterior condylar angle

[0656] Angle between TEA (346) and BCP (366)

[0657] Range is between -5° and 10°

[0658] WL (377): Whiteside Line, connecting KC (330) and TGL (374)

[0659] WL may or may not be orthogonal to TEA and / or BCP

[0660] ATA(388): pulley front axis angle

[0661] Angle between TEA (346) and TL (386)

[0662] Range is between -5° and 10°

Claims

1. A method for selecting a 3D knee prosthesis model for a specific patient, the method comprising: (a) Parameterize the knee prosthesis based on well-defined and independent knee compartments, defining a parametric model of a knee prosthesis divided into multiple compartments. (b) generating a large number of knee joint shapes in the form of 3D knee prosthesis models that reproduce the asymmetry of each individual knee joint 3D shape, thereby being able to reproduce the knee joint motion of substantially any patient by generating shapes that vary the shape parameters, such as the surface and dimensions, of at least one of these compartments, and storing these 3D knee prosthesis models associated with the shape parameters and asymmetry of each model in a database, thereby allowing the asymmetry of the patient's knee joint to be compared with the asymmetry of the plurality of 3D knee prosthesis models, and (c) Study the patient's pathology and develop a standard pre-pathological knee prosthesis that meets the patient's needs, wherein a knee prosthesis best suited to the patient's needs is selected from a large number of knee joint shapes based on the best match of the asymmetry of each model with the patient's criteria, characterized in that a model or multiple models that best reproduce the assumed pre-pathological patient knee joint motion defined by the 3D shape asymmetry of the patient's knee joint are selected from a 3D knee prosthesis model database using a planning algorithm, and further characterized in that the parameterized values ​​of the 3D knee prosthesis model are dynamically linked to a calculation table to define the relationship between each independent compartment and describe the 3D variability of each compartment to reproduce the anatomical variability of a normal knee joint.

2. The method according to claim 1, wherein The planning algorithm is a 3D planning algorithm that has a specific matrix for each plane - preferably the coronal, sagittal and transverse planes - for defining a specific correction of the leg mechanical alignment and the shape of the diseased knee joint to reproduce the mechanical alignment and shape of the knee joint before arthritis.

3. The method according to claim 1 or 2, wherein: The planning algorithm takes anatomical input from landmarks for each plane, calculates preoperative dimensions and angles that define the morphological type and phenotype of the lesion, and outputs parameterized personalized postoperative parameter values ​​that define limb realignment and knee joint shape.

4. A method according to claim 3, wherein limb realignment and parameterization of the knee joint shape is achieved in a manner that allows adjustment of two types of representations / sketches, wherein the first type of representation / sketch involves personalizing the joint representation / sketch defining each compartment articular surface by adjusting the medial-lateral (ML) and anterior-posterior (AP) guide curves on each plane so that the 3D shape of the prosthesis surface matches the patient's knee joint surface; and the second type of representation / sketch involves personalizing the size sketch / representation along the joint surface so that the prosthesis size around the joint correctly fits the patient's size.

5. The method according to claim 1, wherein The selected 3D knee prosthesis model is used to make a suitable prosthesis for the patient.

6. The method according to claim 1, wherein Adjustments to the shape radius (962) of the medial condylar surface of the prosthesis in the coronal and transverse planes, the shape radius of the trochlear surface of the prosthesis in the coronal planes (963), and the shape radius of the lateral condylar surface of the prosthesis in the coronal and transverse planes (964) are independent of each other and of the prosthesis size and the patient's hip-knee-ankle (HKA) mechanical alignment, whether normal, varus, or valgus.

7. The method of claim 1, wherein the shape of the medial condyle surface of the prosthesis in the sagittal plane (972), the shape of the trochlear surface of the prosthesis in the sagittal plane (973), and the shape of the lateral condyle surface of the prosthesis in the sagittal plane (974) are adjusted independently of each other and are independent of the prosthesis size and the patient's hip-knee-ankle (HKA) mechanical alignment, whether normal, varus, or valgus.

8. The method according to claim 1, wherein In step (c), the patient's preoperative condition is measured using CT scan, X-ray, MRI, EOS, weight-bearing or non-weight-bearing conditions, single foot, double foot, varus / valgus stress, or any other measuring device and / or method known in the art, including at least: (i) Hip-knee-ankle (HKA) mechanical alignment, (ii) relative motion of the femur to the tibia, such as a combination of sliding and rolling motions, (iii) femoral and tibial contact surfaces and bone shape, (iv) The shape and position of the patella relative to the femur and tibia, and the contact surface between the patella and femur.

9. The method according to claim 1, wherein The well-defined joint compartments include at least one of the following compartments: an extension compartment, a flexion compartment, a medial compartment (2602, 2606, 2612), a lateral compartment (2604, 2610, 2614), a femoro-tibial compartment, and a femoro-patellar compartment (2602, 2604).

10. The method according to claim 1, wherein The method includes taking the articulation of the patella into account when selecting an appropriate 3D model.

11. The method according to claim 10, wherein: The values ​​of the compartment width and height are independent of the patellar thickness, which is at least 6 mm or greater.

12. The method according to claim 5, wherein the steps of the method include at least one or all of the following steps in order to manufacture a natural personalized implant: (a) Measure the 3D hip-knee-ankle (HKA) mechanical alignment of the knee joint before surgery; (b) If it is not an outlier, the postoperative 3D hip-knee-ankle (HKA) is realigned to reproduce the pre-arthritic hip-knee-ankle (HKA); (c) If it is an abnormal value, the postoperative 3D hip-knee-ankle (HKA) is realigned to determine the corrected pre-arthritis hip-knee-ankle (HKA); (d) Measure the anteroposterior (AP) dimension of the distal femur before surgery; (e) Reproduce the correct anteroposterior (AP) dimensions of the femoral component, ensuring that the implant does not rotate, tilt, or flex in the sagittal plane by more than 10°; (f) The distal and posterior femoral mechanical axis (FMA) and tibial mechanical axis (TMA) were measured before surgery; (g) If there are no abnormal values, the postoperative inclination of the femoral mechanical axis (FMA) and tibial mechanical axis (TMA) should be restored to the inclination of the femoral mechanical axis (FMA) and tibial mechanical axis (TMA) before arthritis, and the femoral torsion before arthritis should be restored; (h) If abnormal, the postoperative FMA and TMA inclinations were determined as the corrected pre-arthritis FMA and TMA inclinations, and femoral torsion was adjusted according to the planned matrix; (i) Measure the preoperative trochlear line (TL) inclination and trochlear depth; (j) following the rules described in the planning matrix, determine which part of the final inclination must be achieved on the bone—e.g., the direction of the resection—and which part must be integrated into the implant—e.g., the condylar offset; (k) If it is not an abnormal value, the postoperative TL inclination is reproduced to the pre-arthritis TL inclination and the trochlear depth is reproduced; (l) If it is an abnormal value, the postoperative TL inclination is determined as the corrected pre-arthritis TL inclination, and the trochlear depth is reproduced by adding a lateral protuberance to the trochlea; (m) If there are no abnormal values, the postoperative condylar and trochlear joint line (JL) curves were reproduced as the pre-arthritis joint line (JL) curves; (n) If abnormal, the postoperative condylar and trochlear joint line curves were determined as the corrected pre-arthritis joint line (JL) curves by correcting the JL curve of the lateral condyle in case of condylar hypoplasia or by correcting the JL curves of both condyles in case of sagittal deformity such as recurvature or large flexion; (o) If it is not an outlier, the ML curves of the condyle and trochlea after surgery are restored to the ML curves before arthritis; (p) If it is an abnormal value, in the case of sagittal deformity such as recurvature or hyperflexion, the postoperative ML curve of the condyle and trochlea is determined as the corrected pre-arthritis ML curve by correcting the ML curve of the lateral condyle or the ML curves of both condyles; (q) Measure the distance from each condylar axis to the center of the knee joint and reproduce the distance; (r) Determine the outer limits of the condylar and trochlear articular surfaces bilaterally to avoid prosthesis overhang or undersizing; (s) Measure the preoperative tibial slope angle; (t) If it is an abnormal value, the postoperative tibial slope (TPS) was reproduced as the corrected pre-arthritis tibial slope (TPS); (u) Determine the tibial component rotation angle by measuring the anterior tibial tuberosity angle (TTA) with it as the anteroposterior (AP) axis and the medial-lateral (ML) axis, an axis passing through the centers of two circles describing the geometry of the medial and lateral tibial surfaces; (v) define the anteroposterior (AP) and mediolateral (ML) position of the tibial keel to ensure that the keel is centered on the tibial metaphysis and / or diaphysis; (w) Determine the outer limits of the tibial component contour to avoid overhanging the prosthesis, which risks contact with surrounding soft tissue and causing pain, or undersizing, which risks subsidence requiring revision; and (x) Measure the distance between the distal femoral resection surface and the proximal tibial resection surface as the expansion gap to ensure the overall thickness of the implant is appropriate.

13. A method according to any one of the preceding claims, wherein: Curve / surface fitting and smoothing techniques are applied between shapes that interact across adjacent bony compartments in order to fuse the prosthetic elements corresponding to the bony compartments, thereby producing a composite knee prosthesis that suits the patient's requirements.

14. A method according to any one of the preceding claims, wherein Use artificial intelligence to calculate the patient's most likely pre-lesion anatomy.

15. A computer-implemented method, wherein: A task-specific program is encoded on a medium for selecting a suitable knee prosthesis for a specific patient according to the method of any of the preceding claims.

16. A partial or full knee prosthesis designed according to the anatomy of an individual patient and reconstructing a natural knee joint according to the method of any one of claims 1 to 14, wherein the geometry is determined by the medial femoral-tibial joint, the lateral femoral-tibial joint, and the femoral-patellar joint, which vary independently of each other.

17. A knee prosthesis according to claim 16, comprising a femoral component, a tibial tray component with an insert and a patellar component, which is designed based on patient-specific data to define a patient-specific prosthesis, wherein the parametric model is specific to each component of the knee prosthesis, such as the femoral component, the tibial tray component, the tibial insert and the patellar component.

18. The knee joint prosthesis according to claim 17, wherein: The femoral component has offset in the distal condyle, posterior condyle, or trochlear eminence.

19. The knee joint prosthesis according to claim 18, wherein: The variations and differences between the condyles (812, 814) are adjusted independently of the angle between the femoral anatomical axis (826) and the femoral mechanical axis (836).

20. The knee joint prosthesis according to claim 19, wherein Adjustment of the condyles (812, 814) is independent of the prosthesis size and the patient's hip-knee-ankle alignment, whether normal, varus, or valgus.

21. Use of the knee prosthesis according to any one of claims 16 to 20 for performing at least one of the following types of correction: - Change of limb mechanical alignment from pathological deviation to pre-arthritic limb mechanical alignment; - From the affected knee joint surface to the anterior arthritic knee joint surface, this involves the medial and lateral curves of the joint surface as well as the sagittal J-curves of the condyles and trochlea; - From the pathological femoral, proximal tibial, and trochlear joint lines to the corresponding prearthritic joint lines; - the distance from the trochlear depth of the lesion to the medial and lateral trochlear eminences to the corresponding anterior arthritis; - The coronal distance from the sagittal axis of the affected condyle and trochlea to the center of the knee joint to the corresponding anterior arthritic distance.

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