RU2588289C2 - Knee joint prosthesis with preservation of cruciate ligament - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: group of inventions relates to medicine. Tibial prosthesis for at least partial substitution of proximal tibia contains medial section of support, lateral support section and connecting area of support, passing between medial section of support and lateral support section and connecting said sections; bottom surface to get in contact with resected surface on the proximal tibia; and keel to be inserted into cavity formed in proximal tibia. Said keel extends from said bottom surface at angle in inferior-back direction and has front section keel, medial section keel and lateral section keel. Front section keel passes along connecting section supports in direction from front-medial to lateral posterolateral. Tibial prosthesis for at least partial substitution of proximal tibia contains articular surface of tibia for coupling with articular surface of condyle of femur, wherein said articular surface of tibia determines mesial edge extending in anterior-posterior direction at mesial edge above articular surface. Said mesial edge is turned relative to appropriate central section of said articular surface. Height, on which mesial edge is turned relative to appropriate central section, decreases in anterior-posterior direction.

EFFECT: inventions provide higher stiffness, rigidity for torsion and bending and bending torsional bending and/or shift between medial and lateral zones of tibia while maintaining cruciate ligament.

17 cl, 100 dwg

Description

LINKS TO RELATED APPLICATIONS

[0001] This application claims the priority of provisional application US No. 61/372,556, "Prosthesis of the knee joint with preservation of the cruciate ligament", filed August 11, 2010, provisional application US No. 61 / 382,287 "Prosthesis with preservation of the cruciate ligament," filed September 13, 2010 , and provisional application US No. 61/299,835 "Tibial implant with preservation of both cruciate ligaments", filed January 29, 2010, which are incorporated herein by reference.

FIELD OF TECHNOLOGY

[0002] The invention relates to prostheses used in knee arthroplasty, for example, tibial and / or femoral implants, which in some cases facilitate the maintenance of one or both cruciate ligaments.

BACKGROUND OF THE INVENTION

[0003] In total knee arthroplasty, it is customary to perform a resection of the entire proximal tibia to create a site for implantation of the tibia on its upper articular surface. With this traditional resection, you usually have to sacrifice one or both ligaments - the anterior cruciate ligament (PCL) and the posterior cruciate ligament (CCL), because with this procedure the place of their attachment is removed in the bone (“intercondylar elevation of the tibia”). Often, the ZKS and PKS functions are replaced by a prosthesis using a stabilizing pin on the tibial insert and the corresponding socket on the femoral component with high accuracy of matching components in the sagittal plane. Although such prostheses generally restore anteroposterior stability, they may not feel as “natural” as a normal knee and retain tissue to a lesser extent.

[0004] In some cases (especially if the patient is a young and active person), it is desirable to leave either both PKC and ZKS, or one of them (if at least one or both cruciate ligaments are suitable for preservation) in order to preserve the natural biomechanics, range of motion and Feel.

[0005] In currently used knee implants with preservation of the ZKS, the posterior part of the tibial insert and / or tibial support may have a small notch where the ZKS can be placed and the place of its attachment in the remaining part of the intercondylar elevation of the tibia. In this case, the surgeon should carefully monitor so as not to resect the bone areas adjacent to the areas of attachment of the SCS. When using such prostheses with preservation of the posterior cruciate ligament, they usually do not preserve PKC.

[0006] In other cases, the surgeon may try to preserve both PKC and ZKS, which can be achieved by installing two unicellular implants. The intercondylar elevation of the tibia and the cruciate ligaments attached to it remain intact. The medial and lateral zones of the upper articular surface of the tibia are resected and replaced with separate unicellular frames and corresponding inserts. One of the drawbacks of installing two separate unisolar implants is the difficulty in properly aligning the two implants relative to each other. Improper alignment of implants can lead to accelerated wear, impaired alignment of the mechanical axes, as a result of which the hip movements may be felt by the patient as unnatural. In addition, the increased complexity of the operation associated with the installation of two implants instead of one can lead to an increase in its duration.

[0007] In order to preserve both PKC and ZKS, instead of using two separate unicellular implants, surgeons can install one implant with the preservation of both cruciate ligaments, which contains one tibial bearing element (which may be an insert) and / or tibial support. Known implants with preservation of both cruciate ligaments essentially consist of an insert and a support, each of these elements having two mono-alkaline sites connected by a thin anterior bridge. Thin front bridges may not withstand the high torsional loads experienced by active patients, and therefore known implants ultimately undergo bending or shearing for half the prescribed period, which requires premature reoperation. Even slight bending and shear deformations in these known devices could degrade performance and ultimately cause weakening of the attachment or detachment of the implant from the bone from the medial, lateral, or both sides.

[0008] Additional disadvantages of the known structures with the preservation of both cruciate ligaments include bone fractures in the area adjacent to the junction of the PCB and the tibia (that is, the front of the intercondylar elevation of the tibia). Such fractures are especially frequent when bone sections located in front of the PCB attachment point are removed to provide enough space for the medial and lateral sides connected by the said thin anterior bridge.

SUMMARY OF THE INVENTION

[0009] Compared to prior art designs, at least some versions of the cruciate ligament preserving tibial prostheses described herein provide greater immobility, torsional and bending stiffness and resistance to torsional bending, bending, and / or shear between the medial and lateral zones tibia.

[0010] In these and other embodiments, a tibial prosthesis for at least partially replacing the proximal tibia is provided, optionally or alternatively, comprising a lower surface configured to contact a resected surface on the proximal tibia, and a keel configured to entering the cavity formed in the proximal tibia, and extending from the indicated lower surface at an angle in the lower back direction. In this case, the tibial prosthesis defines a central notch extending between the medial and lateral portions of the support behind the connecting portion of the support, the specified central notch having sufficient width and length to accommodate a portion of the intercondylar elevation of the tibia, including the attachment point of the anterior cruciate ligament and the attachment point of the posterior cruciate ligament, while the central cut has a medial edge and a lateral edge, and the angle defined by the medial edge and the base of the anterior keel is sharp, and the angle defined by the lateral edge and the base of the anterior keel is obtuse.

[0011] The invention also relates to tibial prostheses in which the posterior surface of the anterior portion of the keel is offset from the posterior surface of the connecting portion of the support.

[0012] The subject of the invention is also tibial prostheses, in which the upper surface of the tibial prosthesis contains at least one fixing element for fixing the tibial insert.

[0013] The subject of the invention is also tibial prostheses, in which the upper surface of the tibial prosthesis contains at least two fixing elements for fixing the medial tibial insert and the lateral tibial insert.

[0014] The subject of the invention is also tibial prostheses for at least partially replacing the proximal tibia and comprising a medial support region having a medial lower surface that comes into contact with a medial resected surface of the proximal tibia, a lateral support region having a lateral lower the surface that comes into contact with the lateral resected surface of the proximal tibia, and the connective support the current flowing between the medial and lateral portions of the support, wherein such tibial prosthesis are asymmetrical with respect to center line extending in the anteroposterior direction between the medial and lateral portions of the support, and a medial support portion protrudes further forward than the lateral support portion.

[0015] The subject of the invention is also tibial prostheses, in which the area defined by the medial portion of the support in the transverse plane is larger than the area defined by the lateral portion of the support in the transverse plane.

[0016] The subject of the invention is also tibial prostheses, which are tibial prostheses with preservation of both cruciate ligaments.

[0017] The subject of the invention is also tibial prostheses, which define a cut that extends essentially in the anteroposterior direction between the medial and lateral sections of the support and is located behind the connecting portion of the support; wherein the cutout is of sufficient length to accommodate at least a portion of the intercondylar elevation of the tibia, including the attachment site of the anterior cruciate ligament and the attachment site of the posterior cruciate ligament.

[0018] The subject of the invention is also tibial prostheses, in which the cut has a medial edge, a lateral edge and a leading edge, the angle defined by the medial and leading edges being acute, and the angle defined by the lateral and leading edges being obtuse.

[0019] A subject of the invention is also a tibial prosthesis for at least partially replacing the proximal tibia and comprising a medial support portion that has a medial lower surface that comes into contact with a medial resected surface of the proximal tibia, a lateral support portion that has a lateral the lower surface coming into contact with the lateral resected surface of the proximal tibia, and the connecting part ca. support extending between the medial and lateral portions of the support and having a bottom connecting surface, keel, part of a cavity formed in the proximal tibia, and the exhaust angled lower-posterior direction from at least one of

surfaces — the medial lower surface, the lateral lower surface, or the connecting lower surface.

[0020] The subject of the invention is also tibial prostheses, in which the keel has a front portion of the keel, the medial portion of the keel extending from the medial lower surface, and the lateral portion of the keel extending from the lateral lower surface, the front portion of the keel extending at an angle in the lower back direction from the connecting bottom surface. The subject of the invention is also tibial prostheses, in which the anterior portion of the keel has a front surface and a rear surface, the front surface extending from the specified lower surface from the front at an angle in the lower rear direction; and the rear surface departs from the specified lower surface from the rear in the lower rear direction.

[0021] The invention also relates to tibial prostheses in which at least a portion of the anterior portion of the keel extends substantially in the medial lateral direction at the connecting portion of the support, at least a portion of the medial portion of the keel extends substantially in the anteroposterior direction in the medial portion the support and at least a portion of the lateral portion of the keel extends essentially in the anteroposterior direction on the lateral portion of the support.

[0022] The subject of the invention is also tibial prostheses, in which the anterior portion of the keel is connected to the medial and lateral portions of the keel by sections of increased thickness.

[0023] The subject of the invention is also tibial prostheses, in which the anterior portion of the keel is connected to the medial and lateral portions of the keel by sections of increased width.

[0024] The subject of the invention is also tibial prostheses, in which the thickness of the connecting portion of the support increases in the anteroposterior direction.

[0025] The subject of the invention is also tibial prostheses, in which the height of the medial and lateral sections of the keel decreases along their length in the anteroposterior direction.

[0026] The subject of the invention is also tibial prostheses, in which the anterior portion of the keel extends along the connecting portion of the support in the direction from the anterior-medial to the posterior-lateral.

[0027] The invention also relates to tibial prostheses in which the posterior surface of the anterior portion of the keel is offset from the posterior surface of the connecting portion of the support.

[0028] The subject of the invention is also tibial prostheses, in which the tibial prosthesis defines a central cut extending between the medial and lateral portions of the support behind the connecting portion of the support and having a sufficient width and length to accommodate a portion of the intercondylar elevation of the tibia, including the attachment point of the anterior cruciate ligaments and the site of attachment of the posterior cruciate ligament.

[0029] The subject of the invention is also tibial prostheses in which the central notch has a medial edge and a lateral edge, the angle defined by the medial edge and the base of the anterior keel is obtuse, and the angle defined by the lateral edge and the base of the anterior keel is obtuse .

[0030] The subject of the invention is also tibial prostheses, which are asymmetrical with respect to the midline extending in the anteroposterior direction between the medial and lateral parts of the support, and in which the medial portion of the support protrudes further forward than the lateral portion of the support.

[0031] These and other embodiments of the invention additionally or alternatively provide a tibial prosthesis for at least partially replacing the proximal tibia and comprising a joint surface of the tibia intended to articulate from the joint surface of the femoral condyle, wherein said joint surface of the tibia the bone defines the mesial edge extending in the anteroposterior direction along the mesial edge of the specified articular surface; moreover, the specified mesial edge is raised relative to the corresponding Central section of the specified articular surface; wherein the height by which the mesial edge is raised relative to the corresponding central portion decreases in the anteroposterior direction.

[0032] The subject of the invention is also tibial prostheses, in which the articular surface of the tibia is the medial articular surface of the tibia, and at least a portion of said medial articular surface of the tibia is concave in the sagittal plane.

[0033] The subject of the invention is also tibial prostheses in which the antero-mesial portion of the medial articular surface of the tibia is bent so as to at least partially correspond to the shape of the articular surface of the femoral condyle.

[0034] The subject of the invention is also tibial prostheses, in which the posterior external portion of the medial articular surface of the tibia is essentially flat and substantially does not correspond to the shape of the articular surface of the femoral condyle.

[0035] The subject of the invention is also tibial prostheses, in which the articular surface of the tibia is the lateral articular surface of the tibia, wherein said lateral articular surface of the tibia is convex in the sagittal plane.

[0036] The subject of the invention is also tibial prostheses, in which the anterior-mesial portion of said lateral articular surface of the tibia is bent so as to at least partially correspond to the shape of the articular surface of the femoral condyle.

[0037] The subject of the invention is also tibial prostheses, in which the posterior-outer portion of the lateral articular surface of the tibia is essentially flat and substantially does not correspond to the shape of the articular surface of the femoral condyle.

[0038] The subject of the invention is also the tibial prosthesis, in which the tibial prosthesis is a tibial insert having a lower surface containing at least one fixing element for fixing on the tibial support.

[0039] The subject of the invention is also a tibial prosthesis for at least partially replacing the proximal tibia and comprising a joint surface of the tibia intended to articulate from the articular surface of the femoral condyle, said articular surface defining a mesial edge extending in the anteroposterior direction along the mesial edge of the specified articular surface and elevated relative to the corresponding central portion of the specified articular of the surface, the antero-mesial portion of the indicated medial articular surface is curved so as to at least partially correspond to the shape of the articular surface of the femoral condyle, and the posterior-external portion of the medial articular surface of the tibia is essentially flat and essentially does not correspond to the shape of the articular surface of the femoral condyle bones.

[0040] The subject of the invention is also a tibial prosthesis for at least partially replacing the proximal tibia, which comprises: the articular surface of the tibia for articulation with the articular surface of the femoral condyle, wherein the anterior-mesial portion of said articular surface is at least partially in shape the articular surface of the condyle of the femur, and the posterior-external portion of the indicated articular surface essentially does not correspond to the shape of the articular surface of the condyle of the femur.

[0041] The subject of the invention is also tibial prostheses in which the anterior mesial region is bent so as to at least partially correspond to the shape of the articular surface of the femoral condyle.

[0042] The subject of the invention is also tibial prostheses, in which the posterior-external portion is essentially flat and substantially does not correspond to the shape of the articular surface of the femoral condyle.

[0043] The subject of the invention is also tibial prostheses in which the articular surface of the tibia is a medial articular surface concave in the sagittal plane.

[0044] The subject of the invention is also tibial prostheses, in which the articular surface of the tibia is a lateral articular surface convex in the sagittal plane.

[0045] The subject of the invention is also tibial prostheses, in which at least one articular surface of the tibia is essentially inclined in the anteroposterior direction.

[0046] The subject of the invention is also tibial prostheses in which at least one articular surface of the tibia has a medial articular surface and a lateral articular surface and the inclination of the medial articular surface in the anteroposterior direction differs from the inclination of the lateral articular surface in the anteroposterior direction.

[0047] The subject of the invention is also tibial prostheses, in which the medial articular surface is connected to the medial insert and the lateral articular surface is connected to the lateral insert, and the thickness of the medial insert in its anterior portion differs from the thickness of the lateral insert in its posterior portion.

[0048] The subject of the invention is also tibial prostheses, in which the medial insert and the lateral insert are included in the set of inserts with different inclinations in the anteroposterior direction.

[0049] The subject of the invention is also tibial prostheses, in which at least one articular surface of the tibia is connected to the tibial support.

[0050] The invention also relates to tibial prostheses in which the thickness of the medial insert in its anterior portion is greater than the thickness of the medial insert in its posterior portion.

[0051] The subject of the invention is also tibial prostheses, in which the thickness of the medial insert in its posterior region differs from the thickness of the lateral insert in its posterior region.

[0052] The invention also relates to tibial prostheses in which the thickness of the lateral insert in its anterior portion is greater than the thickness of the lateral insert in its posterior portion.

[0053] The subject of the invention is also tibial prostheses, in which at least one articular surface of the tibia essentially has an inclination in the medial-lateral direction.

[0054] The subject of the invention is also tibial prostheses, in which at least one articular surface of the tibia includes the medial articular surface and the lateral articular surface, and the inclination of the medial articular surface in the medial-lateral direction differs from the inclination of the lateral articular surface in the medial-lateral direction .

[0055] The subject of the invention is also tibial prostheses, in which the medial articular surface is connected to the medial insert and the lateral articular surface is connected to the lateral insert, the thickness of the medial insert in its front portion being greater than the thickness of the lateral insert in its front portion and the thickness the medial insert in its posterior region is different from the thickness of the lateral insert in its posterior region.

[0056] The subject of the invention is also tibial prostheses, in which the anterior portion of the keel is located anteriorly on the connective lower surface so that upon implantation the patient engages in the anterior zone of the cortical bone layer.

[0057] The subject of the invention is also tibial prostheses, including at least one articular surface of the tibia for articulation with the condylar articular surface of the femoral component, the femoral component containing the medial condyle and the lateral condyle and at least one of the condyles - lateral beveled edge.

[0058] In other embodiments, the subject of the invention is also a tibial prosthesis for at least partially replacing the proximal tibia, which has: a joint surface of the tibia for articulation with the articular surface of the femoral condyle, which defines the mesial edge extending in the anteroposterior direction along the mesial edge of the specified articular surface and raised relative to the corresponding Central portion of the specified articular surface, and the height to which the mesial edge is elevated relative to the corresponding central portion, decreases in the anteroposterior direction, the anterior-mesial portion of the articular surface at least partially matches the shape of the articular surface of the femoral condyle, and the posterior-outer portion of the articular articular surface of the joint essentially does not correspond to the shape articular surface of the femoral condyle.

[0059] The subject of the invention is also tibial prostheses in which the anterior mesial region is curved so as to at least partially correspond to the shape of the articular surface of the femoral condyle.

[0060] The subject of the invention is also tibial prostheses, in which the posterior-external area is essentially flat and essentially does not match the shape of the articular surface of the femoral condyle.

[0061] A subject of the invention is also femoral components having various beveled edges, which provide an additional clearance relative to the intercondylar elevation of the tibia and ZKS, without reducing the covered surface of the bone. In some embodiments of the invention, the medial and / or lateral condyle of the femoral component have a posterior lateral oblique edge. In some embodiments, the leading edge of the femoral component may have a front-lateral beveled edge on the lateral and / or medial side.

[0062] Other applications are apparent from the following detailed description. It is assumed that the detailed description and specific examples of embodiments of the invention are provided for illustrative purposes only and do not limit the scope of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

[0063] The accompanying drawings, which are incorporated in and constitute a part of the description, illustrate some embodiments of the invention and, together with the description, serve to explain the principles of operation and features of the described options, as well as the features by which they are characterized. It should be noted that although most of the drawings or all the drawings contained in this document illustrate implants for use in the patient’s left knee, implants made according to the principle of mirror reflection of implants for the left knee and implants having a symmetrical configuration for use in the left and in right lap. The drawings depict the following.

[0064] Figure 1-3 is a perspective view showing a bottom view of the tibial support in accordance with a first embodiment of the invention, in which there is one or more elements for bone or cement mantle ingrowth and several keel portions.

[0065] Figs. 4-7 show a tibial support in accordance with a second embodiment of the invention, which has a lower recess accommodating a cement mantle.

[0066] Figs. 8-11 show a tibial support in accordance with a third embodiment of the invention.

[0067] Figs. 12-15 show a tibial support in accordance with a fourth embodiment of the invention.

[0068] Figs. 16-19 show a tibial support in accordance with a fifth embodiment of the invention.

[0069] Figs. 20-23 show a tibial support in accordance with a sixth embodiment of the invention.

[0070] Figs. 24-29 show a tibial support in accordance with a seventh embodiment of the invention, having a front portion configured to come into contact with the outer part of the cortical layer of the bone adjacent to the front zone of the cortical layer of the tibia.

[0071] Figures 30-35 and 47 show a tibial support in accordance with an eighth embodiment of the invention having three keel portions.

[0072] Figures 36 and 37 show a tibial support in accordance with a ninth embodiment of the invention, in which there are ledges, relief or jagged elements in the keel portions.

[0073] FIGS. 38-46 show the tibial support of FIGS. 30-35, and 47 assembled with the tibial medial and lateral inserts.

[0074] FIG. 48 illustrates the step of assembling the tibial prosthesis while maintaining both cruciate ligaments, shown in FIGS. 38-46.

[0075] Figures 49-52 are frontal coronal sections that schematically illustrate the mating geometry between the tibial support and the intercondylar elevation of the tibia in accordance with various embodiments of the invention.

[0076] Fig. 53 shows a frontal coronal view of the tibial prosthesis with preservation of both cruciate ligaments, after installation on the proximal tibia.

[0077] Figures 54 and 55 are rear views of the lateral tibial insert.

[0078] Fig. 56 shows a lateral sagittal projection of the lateral insert shown in Figs. 54 and 55.

[0079] Fig. 57 is a coronal sectional view of the lateral insert shown in Figs. 54-56 in front view.

[0080] On Fig presents a sagittal section of the lateral insert in the side view.

[0081] Figures 59 and 61 are rear views of the medial tibial insert.

[0082] Fig. 60 shows the medial sagittal projection of the medial insert shown in Figs. 59 and 61.

[0083] On Fig presents a coronal section of the medial insert in the front view.

[0084] On Fig presents a sagittal cross section of the medial insert in the view from the medial side.

[0085] FIGS. 64-66 illustrate graphically the kinematics of a femoral implant according to one embodiment used with a tibial prosthesis while maintaining both cruciate ligaments shown in FIGS. 38-46.

[0086] FIGS. 67a-67q illustrate the kinematics of FIGS. 64-66 for various bending angles.

[0087] On Fig presents a front view of one of the options for a knee prosthesis with the preservation of both cruciate ligaments (saved PKC and ZKS).

[0088] FIG. 69 is a front view of one embodiment of a knee prosthesis with preservation of the cruciate ligament (retained by the SCS).

[0089] On Fig and 71 presents the front-medial projection of the prosthesis of the knee joint while maintaining the cruciate ligament and the prosthesis of the knee joint while maintaining both cruciate ligaments shown in Fig and 69, respectively.

[0090] Figs. 72 and 73 show a posterior-medial projection of a knee prosthesis while maintaining the cruciate ligament and the knee prosthesis while maintaining both cruciate ligaments shown in Figs. 68 and 69, respectively.

[0091] Figs. 74 and 75 are rear views of the knee prosthesis retaining the cruciate ligament and the knee prosthesis retaining both cruciate ligaments of Figs. 68 and 69, respectively, where an optional element is shown — beveled edges made in the femoral component for clearance clearance.

[0092] On Fig presents a top view of the medial condyle of the femur, where in partial section shows an optional element - the posterior-lateral beveled edge in accordance with some variants of the invention.

[0093] On Fig and 78 presents the lateral sagittal projection of the prosthesis of the knee joint while maintaining the cruciate ligament and the prosthesis of the knee joint while maintaining both cruciate ligaments shown in Fig and 69, respectively.

[0094] On Fig and 80 presents the rear-lateral projection of the prosthesis of the knee joint while maintaining the cruciate ligament and the prosthesis of the knee joint while maintaining both cruciate ligaments shown in Fig and 69, respectively.

[0095] On Fig presents a top view of the femoral component shown in Figa-80.

[0096] Figs. 82-84 are perspective views showing various views of the medial and lateral inserts shown in Figs. 54-63.

[0097] FIG. 85 shows a two-piece knee joint implant according to another embodiment of the invention, which uses a medial insert in accordance with some embodiments of the invention and which can be used in conjunction with a medial single condyle tibial support (not shown) or, alternatively, , can be performed as a lateral two-component knee joint implant (not shown).

[0098] Fig. 86 shows a medial single-muscle knee joint implant in accordance with yet another embodiment of the invention that utilizes a medial insert in accordance with some embodiments of the invention and which can be used in conjunction with a medial single-muscular tibial support (not shown).

[0099] Fig. 87 shows a lateral unisomic knee joint implant according to another embodiment of the invention, which uses a lateral insert in accordance with some embodiments of the invention and which can be used in conjunction with a lateral unisomic tibial support (not shown).

[00100] On Fig shows a monolithic prosthesis with the preservation of both cruciate ligaments in accordance with one embodiment of the invention, in which the tibial support has integral parts of the joint surface.

[00101] On Fig shows a monolithic prosthesis with the preservation of both cruciate ligaments in accordance with one embodiment of the invention, in which the tibial support is a fully or partially porous nozzle having integral parts of the joint with it.

[00102] On Figa-90e presents various sagittal sections of the lateral insert in the form from the medial side.

[00103] Figs. 91a-91k show various coronal sections of the lateral insert in a rear view.

[00104] Figs. 92a-92e show various sagittal sections of the medial insert in lateral view.

[00105] Figs. 93a-93m show various coronal sections of the medial insert in a rear view.

[00106] Fig. 94 shows a medial sagittal projection of a femoral component in accordance with one embodiment of the invention.

[00107] FIGS. 95a-95k show various coronal sections along lines AA to KK shown respectively in FIG. 94.

[00108] Fig. 96 is a perspective view showing a view of a resected tibia prepared to fit the tibial support of Figs. 30-35 and 47.

[00109] Figs. 97-98 are perspective views of a tibial support in accordance with a tenth embodiment that includes one or more pins.

[00110] Fig. 99 shows a sagittal section of a lateral insert in accordance with one embodiment.

[00111] Fig. 100 shows a sagittal section of a medial insert in accordance with one embodiment.

DETAILED DESCRIPTION OF THE INVENTION

[00112] The following description includes exemplary embodiments of the invention and does not limit the scope of the invention, its scope or methods of use.

[00113] 1. Tibial support

[00114] Figure 1-46 and 97-98 show various, but not limiting the scope of the invention, variants of the tibial supports, some of the features of which are described below.

[00115] Figure 1-3 shows the lower side of the tibial support in accordance with the first embodiment of the invention. In general, the support 10 has a medial portion 12a, a lateral portion 12b and a connecting portion 12c. In this particular embodiment, the support 10 may have an asymmetric shape in some respects. For example, as shown in FIG. 3, the medial portion 12a is larger than the lateral portion 12b, and fragments of the medial portion 12a are more protruding than the lateral portion 12b. In other embodiments, the support may differ in another type of asymmetry or be symmetrical.

[00116] The support 10 shown in FIGS. 1-3 has edges 15a and 15b that define a cutout 8 between the medial section 12a and the lateral section 12b, providing a clearance for the preserved intercondylar elevation of the tibia or parts thereof. In the embodiment shown in FIGS. 1-3, the central portion with a notch 8 is approximately one quarter to one third of the tibia width in the medial-lateral direction and thus allows for the introduction of most of the intercondylar elevation of the tibia, although in some embodiments of the invention, it may be desirable to resect at least the front parts of the elevation. Thus, in some embodiments of the invention, the anterior portion of the intercondylar elevation of the tibia can be resected flush with the medial and lateral resections in the tibia to make room for the connecting portion 12c. The amount of tibia removed to make room for the connecting portion 12c may, in some embodiments, be from 1/5 to 1/8 of the entire size in the anteroposterior direction of the intercondylar elevation of the tibia prior to bone preparation. In this particular embodiment, the connecting portion 12c is designed to preserve and protect the bone near the attachment point of the PCB, as well as to eliminate stress concentrators.

[00117] As shown in the drawing, the central portion with a notch 8 is generally centered in the medial-lateral direction of the tibial support 10, which allows you to maintain the same medial / lateral width of the medial 12a and lateral 12b sections, (and, in some embodiments, the medial / lateral width of the liners used with the support 10). In other embodiments, there is no need for the medial 12a and lateral 12b sections to have the same size in the medial / lateral direction.

[00118] The support 10 shown in FIGS. 1-3 contains a keel extending distally from it. In some embodiments of the invention, the keel may facilitate fixation and retention of support on the tibia of the patient. In some embodiments of the invention, the keel can increase the strength, torsional rigidity and stability of the support. In the particular embodiment shown here, the keel portions 14a and 16a extend from the medial support portion 12a, the keel portions 14b and 16b depart from the lateral portion 12b, and the keel portion 14c departs from the connecting portion 12c.

[00119] In some embodiments of the invention, the keel portions may extend at an angle of from about 90 degrees to, respectively, 45 degrees relative to the underside of the support 10, although larger or smaller angles are also possible. In some embodiments of the invention, the keel portions may extend distally at the same angle or at different angles compared to each other. In some embodiments of the invention, the keel portions may be symmetrical with respect to each other or may be asymmetric in accordance with the anatomy of the bone or for other reasons. In other embodiments (discussed below), the supports may have more or less keel portions than the support 10 shown in FIGS. 1-3, and / or keel portions may have a different configuration.

[00120] In the embodiment shown in FIGS. 1-3, as best seen in FIG. 3, the front rib 14c is angled in the medial lateral direction, so that its medial portions are located more in front than the side portions. The front rib 14c is also inclined in the direction from the front-top to the back-bottom, and some reasons for this will be disclosed in the description of subsequent variants of the invention in this document. The front rib 16c also has a distal notch 13 (shown in FIG. 2), which allows to optimize flexibility, reduce material consumption, improve load distribution and / or provide additional rotational stability.

[00121] The support shown in FIGS. 1-3 has keel portions 16a, 16b extending distally from the medial 12a and lateral 12b of the portions of the support 10, which in some embodiments of the invention can increase the stability and / or stiffness of the support 10 with respect to the forces which can be attached to it and at least have a component directed in the front and / or rear direction. Increased anteroposterior stability may be desirable in some, although not necessarily all, versions, since certain femoral components (e.g., femoral component 400 shown in Figs. 67A-D) may, in certain cases and in a particular application, be affected by such efforts on the tibial components used with them. In some embodiments of the invention, the angle of insertion and placement of one or more keel portions 16a, 16b can be spatially optimized to improve tibial fixation and fit, as well as anteroposterior and rotational stability in the bone. Other configurations of keel portions 16a, 16b other than those shown directly in the drawings are also possible.

[00122] The surface of the tibial support 10 in some embodiments of the invention may be optimally processed for use in accordance with cement or cementless methods. In some embodiments of the invention, the supports have smooth or polished surfaces, or sandblasted surfaces, or surfaces that are roughened in another way, and may also include elements such as ribs, grooves, ledges, grooves, needles, spikes, and combinations thereof. The lower or distal surface of the medial section 12a and the lateral section 12b may also contain elements for bone ingrowth, for example porous surfaces for ingrowth with or without hydroxyapatite. In some embodiments of the invention, one or more pockets of a support may be provided on the distal or lower surface to place the cement mantle therein using the cement method. One or more pockets may contain means for increasing the contact area between the implant and the cement mantle, for example, a “waffle” relief, grooves, ribs, ledges, cuts, porous fragments, protrusions or bulges 15c, which can be made of porous metal or represent a section surface subjected to special treatment.

[00123] The keel portions 14a, 14b, 14c, 16a, and 16b shown in Figs. 1-3 have outer surfaces 14a ', 14b', 14c ', 16a', 16b ', respectively, and inner surfaces 14a' ' , 14b ″, 14c ″, 16a ″, 16b ″, respectively. In some embodiments of the invention, these surfaces may contain porous areas for bone ingrowth, areas that are roughened by special treatment may include hydroxyapatite or biological preparations to improve fixation. In some embodiments of the invention, the inner 14a, 14b, 14c, 16a, 16b, and 14a, 14b, 14c, 16a, 16b 'of the surface may be parallel to each other or may be directed at sharp angles relative to each other. Although they are depicted substantially flat, surfaces 14a, 14b, 14c, 16a, 16b, 14a, 14b, 14c, 16a, 16b of portions 14a, 14b, 14c, 16a , 16b keel, respectively, can be more complex, for example, to represent bi-spline or arcuate surfaces.

[00124] The support 10 shown in FIGS. 1-3 contains transitional portions or reinforcing elements 18 located between the anterior 14c, medial 14a and lateral 14b of the keel, which may in some embodiments of the invention help minimize the amount of bone removed to accommodate implant. For example, on the medial side, the strategic transitional reinforcing element 18a prevents the lower edge of the keel from approaching the cortical layer of the tibia. Thus, the reinforcing elements 18 form transition zones between the anterior keel 14c and the medial 14a and between the anterior 14c and the lateral keel 14b.

[00125] FIGS. 4-7 illustrate yet another embodiment of the tibial support, support 20. Like the embodiment shown in FIGS. 1-3, the tibial support 20 has a medial portion 22a from which the medial rib 24a extends, a lateral portion 22b from which the lateral rib 24b departs, and the connecting (or front) portion 22c, from which the front rib 24c departs. The support 20 may also comprise an oblique medial rib 26a and an oblique lateral rib 26b. Like the embodiment shown in FIGS. 1-3, the front rib 24c may have a distal notch 23 (shown in FIG. 6). The upper surfaces of the support 20 may have a medial fixation portion 22a 'and a lateral fixation portion 22b' in the form of recesses into which the medial and lateral inserts can enter, respectively. The support 20 also has a medial bone contact surface 22a ″ and a lateral bone contact surface 22b ″ for the cement mantle or one that may be a porous bone ingrowth portion.

[00126] The reinforcing elements 28a, 28b are generally cylindrical to facilitate bone preparation. For example, drills or reamers of small diameters can be used to prepare the bone in places where the thicker sections formed at the intersection between sections 24a, 24c, and 24b should enter. A cylindrical or curved arcuate shape of the reinforcing element 28a, 28b generally increases the strength in the cut angles between the medial 24a and lateral 24b sections, where in some embodiments of the invention there may be a high load zone.

[00127] FIGS. 8-11 illustrate a third embodiment of the invention — the tibial support 30, which has features similar to those of the supports 10 and 20 described above. The support 30 has a medial elevation edge 39a, a lateral elevation edge 39b and a leading elevation edge 39c shown in FIGS. 8 and 11, which can surround the cut-out region for the intercondylar elevation, increasing the overall strength of the support 30 along its inner sides. This additional strength can be especially important in some embodiments of the invention when it is necessary to resist torsional forces or other forces acting on the support 30 when it is loaded from the rear.

[00128] FIGS. 12-15 illustrate a fourth embodiment of the invention, a support 40, which has features similar to those of the supports described above, with some modifications. For example, as shown in FIG. 14, cutout 43 is more pronounced. The configuration of the reinforcing elements 48a, 48b is also different: the reinforcing elements 48a, 48b protrude backward and also protrude distally further than the keel portions, for example, the medial keel portion 44a, as shown in FIG. 15.

[00129] FIGS. 16-19 illustrate a fifth embodiment of the invention — a support 50, which also has features similar to those of the supports described above, with some modifications. For example, as shown in FIG. 17, reinforcing elements 58a and 58b are more pronounced. In addition, as shown in FIG. 17, the oblique ribs 56a and 56b are otherwise arranged relative to the medial and lateral portions 52a, 52b compared to other embodiments.

[00130] FIGS. 20-23 illustrate a sixth embodiment of the invention, a support 60, which has features similar to those of the supports described above, with some modifications. For example, the support 60 comprises a medial rib 64a, a front rib 64c and a lateral rib 64b, but does not contain oblique ribs. As shown in FIG. 22, the front rib 64c has grooves or other surface modifications. The support 60 also has an elevation leading edge 69c that extends proximally from the upper surface of the support (as shown in FIGS. 22-23).

[00131] FIGS. 24-29 illustrate a seventh embodiment of the invention — a support 70, which has features similar to those of the supports described above, with some modifications. The support 70 comprises a medial rib 74a, a front rib 74c, a lateral rib 74b, and oblique ribs 76a, 76b that extend at an angle from the medial and lateral ribs 74a, 74b, respectively. The anterior rib 74c is located more in front than in other embodiments, which allows it to cling to the anterior zone of the cortical bone layer with its inner surface 74c '' and remain on the outer surface of the cortical bone layer near the anterior zone of this layer. The support 70 has a medial elevation edge 79a, a lateral elevation edge 79b, and an elevation leading edge 79c shown in FIGS. 26 and 29, which may be on the medial and lateral sides of the intercondylar elevation, increasing the overall strength of the support 70 along its inner sides.

[00132] FIGS. 30-35 and 47 illustrate an eighth embodiment of the invention — a support 80 having three keel portions — a medial portion 84a, anterior portion 84c, and a lateral portion 84b. Fig. 96 shows a resected tibia 220 prepared for placement of a support 80 therein. As shown in Fig. 96, the intercondylar elevation of the tibia 222 is not affected by the resection. As shown in FIG. 35, the anterior keel portion 84c extends distally further than the medial and lateral portions 84a, 84b, which in some embodiments of the invention may enhance fixation. In addition, as in some previous embodiments of the invention, the anterior keel portion 84c is positioned at an angle in the direction from the upper front to lower rear (as shown in FIG. 35) with respect to the tibial resection plane and / or the lower side of the front portion 82c, which in some embodiments of the invention can facilitate deepening of the keel portion to give strength and enhance fixation without disturbing the anterior zone of the tibial cortical layer, and, in some embodiments of the invention, without leading to the placement of the joint Yelnia section 82c so far behind that it will interfere with the point of attachment to the PCB intercondylar elevation. In some embodiments of the invention, by tilting the anterior keel portion 84c, it is possible to prevent the proximal tibia from penetrating into the anterior zone of the cortical layer or splitting or splitting of the proximal tibia during implant placement and implantation. In some embodiments of the invention, the inclination of the anterior keel portion 84c allows for an increase in the amount of bone between the anterior rib 84c and the anterior region of the tibial cortical layer. In this particular embodiment, the angle α between the inner surface 84c ″ of the front keel portion 82c and the bone in contact with the bottom surface 82a ″, 82b ″ of the support 80 is from about 50 to about 90 degrees, more preferably from about 65 to about 75 degrees, for example, about 70 degrees. In some embodiments of the invention, the medial portion 84a and the lateral keel portion 84b also extend at an angle in the lower-rear direction with some of their fragments, for example, on the upper surfaces of these keel portions.

[00133] As best seen in FIG. 35, in some embodiments of the invention, the posterior surface of the anterior connecting portion 84c (adjacent to the edge 89c) and the rear side 84c of the anterior keel portion 84c may not intersect at the level of the proximal area of the tibia resection plane, which in some cases helps to avoid a decrease in strength or even fractures of the anterior portion of the intercondylar elevation of the tibia during preparation of the anterior portion of the keel. In other words, the intersection zone of these two surfaces is offset by a predetermined distance (distance r in FIG. 35) so as not to interfere with the preservation of the intercondylar elevation when preparing the bone for joining the anterior keel portion 82c.

[00134] As also shown in FIGS. 34 and 35, the angle θ between the edge 89c of the front connecting portion 82c and the bone in contact with the bottom surface 82a ″, 82b ″ of the support 80, in this particular embodiment, is from about 60 to about 90 degrees, more preferably from about 82 to about 88 degrees, for example, about 85 degrees. As a result, such an angle θ forms a cutout, which allows to increase the amount of bone stored at the front of the base of the prepared front region of the intercondylar eminence, and thereby reduces the load on the bone. In other words, the front notch in the intercondylar eminence in some embodiments of the invention is positioned at an angle so that the base of the elevation is larger than its proximal area, which increases the resistance of the intercondylar elevation 222 to pull. The cut-out formed by the angle θ also allows bone cement, paste or other biological materials to be injected that can flow freely into the front parts of the base of the intercondylar eminence 222, thereby strengthening and filling stress concentrators, which can be located in the corners of the front part of the base of the intermuscular eminences, where a cut in the anterior region of the intercondylar elevation is located next to the site of proximal tibial resection. Material placed or pressed into the cutout at an angle θ between the bone and the tibial support 80 or placed next to this cutout can also hold parts of the bone in place after implantation, prevent microdisplacement of the tibial support 80 and prevent subsidence. As mentioned above, the named angles and other geometric parameters can be changed to best suit the individual anatomical features of the patient.

[00135] As best seen in FIG. 30, the angle γ between the front rib 84c and the inner surface of the medial portion 82a in this embodiment of the invention is from about 75 to about 90 degrees, more preferably from about 82 to about 88 degrees, for example, about 85.5 degrees. As best seen in FIG. 32, the angle β between the front connecting portion 82c and the inner surface of the lateral portion 82b in this embodiment of the invention is from about 90 to about 120 degrees, more preferably from about 92 to about 98 degrees, for example about 95 degrees. In other words, the leading edge of the notch between the medial 82a and the lateral 82b is angled so that the medial side of the connecting portion 82c is more in front than the lateral side of the connecting portion 82c. The additional space in front of the front-medial side of the cutout of the support 80 in this embodiment of the invention creates a greater clearance for the PCB, which generally is located more in front on the medial sides of the PCB attachment area. The more rearward location of the lateral side of the connecting portion 82c also eliminates possible obstacles to the attachment of the posterior lateral bundle of the PCB and leaves more material on the lateral side to increase the strength of the asymmetric structure. For tibial supports, which are custom-made or taking into account the characteristics of the patient, the above-mentioned values of the angles and other geometric characteristics may be different in order to optimally correspond to the individual anatomical features of the patient. Such changes can be made to ensure the proper balance between bone preservation and strength.

[00136] In the embodiment of the invention shown in FIGS. 30-35 and 47, the keel portions 84a, 84b, 84c expand or thicken as they approach the intersection with other keel portions. In some embodiments of the invention, for example, in the embodiment shown in FIGS. 30-35, the transitional and connecting reinforcing elements 88a, 88b on the sides of the front portion 82c of the support 80 can reduce stress concentrators as the upper and inner surfaces of the support 80 move to the front portion 82c from medial 82a and lateral 82b sections where the thickness of the material is limited in order to maintain a minimum thickness of the tibial insert and allow inserts to be inserted and fixed on the fixing sections 82a ', 82b' from the front ones.

[00137] As best seen in FIG. 35, the height in the upper-lower direction of the medial 84a and lateral 84b of the keel portions can generally decrease at the back in order to optimize the load distribution in some embodiments of the invention and provide sufficient flexibility to prevent stress shielding. In addition, the keel portions 84a, 84b, 84c are generally angled in the anteroposterior direction to better support the medial 82a and lateral 82b tibial support portions 80. The angles and arrangement of the keel portions 84a, 84b, 84c in the anteroposterior and medial-lateral directions, in at least some embodiments of the invention, provide at least some balance between: (a) supporting a central portion of each of the side portions 82a, 82b of the support 80 while loading the support 80 from the rear; and (b) supporting the edges of the medial and lateral portions 82a, 82b of the support 80 during extreme loading of the edges on the medial or lateral sides of the support 80. In addition, the angles and location of the keel portions 84a, 84b, 84c can be determined so as to provide stability to these loads, it is not necessary to provide for a relatively wide anterior portion 84c of the keel, which, if too wide, would interfere with or pass through the anterior zone of the tibial layer of the tibia 220. Although the illustrations show that the lower edge of the keel lateral portions 84a, 84b of the keel is straight, in other embodiments, the distal edges can be curved or stepped, so that the change in the depth of the medial and lateral keel portions 84a 84b will be described by a non-linear function of moving backward. The curved or stepped lower edges of the keel lateral portions 84a, 84b (such as those shown in FIG. 7) can optimize the load distribution in the tibial support 80.

[00138] In some embodiments of the invention, for example, shown in FIGS. 30-35 and 47, the medial and lateral keel portions 84a, 84b may have one or more reinforcing bridges 85a, 85b that connect the cement peripheral edges 87a, 87b to portions 84a, 84b of the keel (as shown in FIGS. 34-35). Reinforcing bridges 85a, 85b can be strategically positioned so that they extend under all points subject to high loads, such as the angles of the fixing sections 82a ', 82b' (as shown in Figs. 32-33), which, for example, may be recesses or pockets located on the proximal side of the medial 82a and lateral 84a sections, and the shape of which allows the medial and lateral tibial inserts 110, 120 to be inserted into them (described below). Although not shown, the lintels 85a, 85b may also be located in the upper recesses of the fixing sections 82a ', 82b' if the lower sides of the tibial inserts 110, 120 will have additional recesses to accommodate the jumpers 85a, 85b.

[00139] As shown in FIG. 34, between the edges 89a, 89b, 89c of the elevation of the tibial support 80, there may be rounded edges 81a, 81b forming the inner surface of the cutout into which the intercondylar elevation of the tibia can be placed. These rounded edges 81a, 81b in some embodiments of the invention can reduce stress concentrators in these areas, thereby preventing breakdowns due to acute angles, typical of known structures with the preservation of both cruciate ligaments. The rounding of the corners at the edges in some embodiments of the invention will help to avoid those obstacles that the implant could create for the attachment point of the anterior cruciate ligament on the tibia 220.

[00140] In addition, as in other embodiments, walls of increased height or elevation edges 89a, 89b, 89c (as shown, for example, in FIG. 33) may be provided along the medial and lateral sides of the cutout region for the intercondylar elevation, which will increase the total strength of the support 80 along its inner sides. This additional strength can facilitate, at least in some embodiments of the invention, resistance to stresses and other forces acting on the support 80 when it is loaded from the rear. In addition, the connection of the elevation edges 89a, 89b, 89c with the lower surfaces 82a ″, 82b ″ may extend the boundaries of the cement mantle and allow it to cover a larger space along the base of the prepared intercondylar elevation of the tibia. This additional cement at the corners of the base and the sides of the intercondylar elevation of the tibia and between this elevation and support 80 can generally improve the resistance of the elevation to fracture. Walls of increased height or elevation edge 89a, 89b, 89c can also serve to isolate the tibial inserts from the cement mantle and from the vertical walls of the prepared intercondylar elevation of the tibia or serve as props to give the tibial inserts medial lateral stability.

[00141] The connecting front portion 82c can define a substantially trapezoidal sagittal shape both in a sagittal cross section (as, for example, shown in FIG. 35) and in a plan view (as shown, for example, in FIG. 33). In this embodiment, the anterior keel portion 82c expands (in the medial-lateral direction) as it moves backward. Such a configuration may in some embodiments of the invention limit the concentration of stresses in the front portion 82c and maintain a more even load distribution, facilitating the movement of the stresses forward to areas with fewer stress concentrators.

[00142] In this particular embodiment, the connecting front portion 82c of the tibial support 80 has a slope, that is, its thickness (upper-lower direction) increases in the backward direction, which in some embodiments of the invention can increase the strength of the support 80 near the edge of the intercondylar elevation, while providing greater flexibility in the front sections of the support 80 with a more even distribution of stresses when the support 80 is loaded from the rear. So, if either the medial section 82a or the lateral section 82b is loaded back more than the other of these sections (for example, with strong bending), torsion forces can occur in the front section 82c. In such situations, the flexibility provided by the thinner front portion of the front portion 82c allows for more even distribution of torsional stresses, and the thicker rear portion of the front portion 82c and the raised front elevation edge 89c provide additional strength and rigidity.

[00143] Fig. 41 shows the tibial support 80 with the tibial inserts 110 and 120 mounted thereon. As shown in Fig. 41, the transition from the thicker portion of the edge 89c in the front portion 82c to the concave medial 89a and lateral 89b elevation edges allows you to increase the mass of material in the high-voltage section at the corners of the cutout of the support 80. Therefore, the medial 89a and lateral 89b edges can be shorter than the front section 82c and the front elevation edge 89c, without reducing the strength of the tibial support 80. In addition, reducing the height you 89a medial and lateral edges 89b can prevent the contact between the upper edge portions 89a, 89b and a femoral component 400, especially in cases where a thin polymeric liners 110, 120 are used.

[00144] Returning to FIGS. 32-33, it is noted that the upper or proximal side of the tibial support 80 may have a medial fixation portion 82a 'and a lateral fixation portion 82b', each of which has a fixation element for securing the polymer tibial insert. Such locking elements may contain, for example, certain types of elements (or combinations thereof) from the following series: notches, dovetail joints, joints with female and male parts, grooves, ribs, interference fit, spikes, latches, pins, magnets and other connectors known to those skilled in the art. The locking elements may allow moderate rotational or translational movement of the liners with a mobile installation, as described below. FIGS. 38-46 show the tibial support 80 assembly with a medial joint insert 110 and a lateral joint insert 120. In some embodiments of the invention, the configuration of the perimeter of the tibial support 80 and / or tibial inserts 110, 120 is brought into close correspondence with the perimeter of the resected part of the proximal tibia.

[00145] Although not shown in the drawings, the upper surfaces of the tibial support 80 may be shaped to allow use with a mobile unit. In other words, the medial and lateral fixing sections in some embodiments of the invention can be equipped with devices for securing the medial and lateral inserts on a support that allows some limited rotational movement of the inserts. Such devices may include, for example, joints with female and male parts, such as spike joints or circular cutouts, that secure the liners in relation to five degrees of freedom, while allowing their controlled rotation relative to the support. Other devices may be provided, for example with cam guides, which allow a controlled translational movement of the liners in one or more directions, including the anteroposterior and medial-lateral directions.

[00146] Figures 36-37 illustrate a ninth embodiment of the tibial support, the tibial support 90. As in some other embodiments described hereinabove, the tibial support 90 has keel portions deflecting backward. In this particular embodiment, the keel sections 94a, 94b, 94c are stepped, which increases bone compression during implant insertion and creates pressure zones at the corners of the stepped protrusions. The keel support 90 with stepped keel sections 94a, 94b, 94c may also contribute to better fixation using cement and cementless methods. The tools used to prepare the tibia for inserting the tibial support into it may include, in some embodiments, a percussion instrument with or without a stepped surface and providing more or less penetration and interference.

[00147] Figs. 97-98 illustrate a tenth embodiment of the tibial support, the tibial support 1700. As in some other embodiments described hereinabove, the tibial support 1700 comprises keel portions deflecting backward. Pins 1710 or other suitable structural elements are also provided in accordance with this embodiment, providing enhanced fixation in the prepared tibia 220.

[00148] Figures 49-52 are frontal coronal sections showing the mating geometry between the tibial supports 80a-80d having medial elevation edges 89a-89a ″ ″ and lateral elevation edges 89b'-89b ″ ’, and intercondylar elevation 222 in the prepared tibia 220. As shown in the drawings, one or both cruciate ligaments are preserved - the anterior PCS 310 and the posterior SCS 320. Fig. 53 shows a frontal coronal view of the tibial support 80 assembly with inserts 110, 120 together with prepared tibial braid Tew 220 and its intercondylar elevation 222.

[00149] In some embodiments of the invention, the relative length of the front portion of the keel and the angle can be optimized in accordance with the collected data. It was found that for a given length of the anterior keel, an increase in the angle of deviation of the anterior keel from the vertical generally increases the amount by which the anterior keel cuts into the front of the intercondylar elevation, and that a too large angle can reduce the strength of the support. If the anterior portion of the keel crashes too much into the elevation, a threat to the intercondylar elevation itself may also occur. Some of the tibial support options were obtained by optimizing the shape for a more efficient distribution of stresses on the support, clarifying the final strength by analyzing previous versions of the tibial supports in which it broke, and iterative modeling on a computer. Autopsy data were used to determine the possible amount of bone removed and its localization in anatomical aspect, and this information was also used to determine the optimal number, configuration, and orientation of keel sections in terms of increasing strength and enhancing initial fixation in various ways. The inventors considered the possibility of manufacturing the tibial support of the same structure from various materials with high and low fatigue strength, trying to increase the rigidity of the structure regardless of the strength and properties of the material.

[00150] The selected keel shape as a whole, in combination with a certain angle of the front portion of the keel, which in some embodiments is approximately 70 degrees, essentially creates a “self-locking” property. In other words, since the front portion of the keel cuts into the cancellous bone (from the proximal area of the upper surface of the joint with the tibia), this ensures the presence of holding forces that counteract the stretching forces.

[00151] The invention also relates to methods for implanting a tibial prosthesis. The method includes the steps of determining the depth of resection, determining the preferred spatial orientation of the prosthesis, resecting the medial and lateral zones of the upper surface of the tibia without damaging the intercondylar eminence and the attached PCS / ZKS, forming the areas necessary for introducing one or more fixing elements into them the underside of the tibial prosthesis, and installing the tibial prosthesis using cement or cementless methods.

[00152] 2. Tibial inserts

[00153] The above and other embodiments provide improved tibial inserts, including the medial insert 110 and the lateral insert 120 shown in Figs. 38-44 in assembly with a support 80. In some embodiments, the medial insert 110 is thinner than the lateral insert 120, reproducing varus articular displacement in the femoral component. In some embodiments of the invention, the lateral insert 120 may be, for example, approximately 2.5 mm thicker than the medial insert 120, providing a 3 ° varus articular displacement that will correspond to a 3 ° varus articular displacement line in the femoral component. The geometry of the tibial articulation in some embodiments of the invention generally has a concave medial section opposite the medial insert 110 and a convex lateral section opposite the lateral insert 120. One or both of the inserts 110, 120 can be formed by fitting their inner sections in the coronal direction. This adjustment can be carried out, for example, due to the mesial edge, which, as described in more detail below, can vary in height in the front-rear direction.

[00154] Figs. 54-58 show various views of a variant of the lateral insert 120, and Figs. 59-63 show various views of a variant of the medial insert 110.

[00155] The lateral liner 120 defines the superior articular surface, and FIGS. 54-58 show several of its different contours in different planes. On Fig and 58 shows sections of the lateral liner 120 in certain coronal (Fig) and sagittal (Fig) planes. Fig. 57 illustrates a contour 126a defined with respect to the front coronal cross section of the lateral liner 120. Fig. 58 illustrates a contour 124b defined with respect to the middle, sagittal cross section of the lateral liner 120. Fig. 90a-e shows a series of sagittal sections of a variant of the left lateral liner, which show the contours of this insert from relatively mesial (e.g., Fig. 90a) to relatively external (e.g., Fig. 90e) sections of the insert. On Figa-k presents a series of coronal sections of the same variant, which is shown in Figa, which shows the coronal sections from relatively front (for example, Fig. 91a) to relatively rear (for example Fig. 91k) sections of the liner.

[00156] As shown in FIGS. 54-58 and 90-91 and explained in more detail below, in respective embodiments of the invention, the lateral liner 120 defines the mesial edge 128 and the peripheral beveled edge 129. In some embodiments of the invention, at least some portions of the front sections and contours lateral insert 120 is relatively more consistent with the condyle of the femur than other portions of insert 120. As shown in FIG. 56, lateral insert 120 may also contain peripheral steps 127a, 127b. Figures 56 and 58 illustrate a locking mechanism 122 that is used to secure the lateral liner 120 to the tibial support.

[00157] As shown in Figs. 54-58 and 90-91, in respective embodiments, the mesial edge 128 is elevated relative to other portions and contours of the liner 120. As shown in Fig. 58, which illustrates the sagittal section of the liner 120 passing through its middle the raised elevated mesial edge 128 extends from the front to the rear portion of the liner 120. In some embodiments, the mesial edge 128 provides resistance to lateral movement of the femur and prevents collision between the femoral component 400 and intercondylar elevation of 222 tibia. The height of the mesial edge can be chosen so as to provide the desired level of resistance, while the greater the height, the greater the resistance. As shown in the drawings relating to these embodiments, the height of the mesial edge relative to other portions of the liner 120 gradually decreases in the front-rear direction. In the embodiments depicted in FIGS. 54-58 and 90-91, the outer sides (at the tapered edge 129) of the lateral liner 120 are substantially flat and have little or no fit to the condylar articular surfaces of the femur. In some embodiments of the invention, the maximum height of the mesial edge 128 is from about 0.064 cm (0.025 inches) to about (0.32 cm) 0.125 inches relative to the substantially flat outer sides. In some embodiments of the invention, the maximum height of the mesial edge 128 for the lateral liner 120 is approximately 0.09 cm (0.035 inches) and approximately 0.17 cm (0.065 inches).

[00158] Figures 59-63 illustrate an embodiment of a medial insert 110 that defines an upper articular surface, representing several different contours in different planes. For example, FIG. 62 shows a coronal section of the medial insert 110 relative to the middle portion of the insert 110, where the coronal contour 116a is determined. On Fig shows a sagittal section of the medial insert 110 relative to the middle section of the insert, where the contour 114b is determined. On Figa-e presents a series of sagittal sections of a variant of the left medial insert, which shows the contours of this insert from relatively mesial (e.g., Fig. 92a) to relatively external (e.g., Fig. 92e) sections of the insert. On figa-m presents a series of coronal sections of the same variant, which is shown in Fig.92-e, which shows the coronal sections from relatively front (for example, Fig.93a) to relatively rear (for example, Fig.93m) sections of the liner.

[00159] Like the side insert, the medial insert 110 also includes a mesial edge 118 and a peripheral beveled edge 119 (for example, as shown in FIG. 60). In some embodiments of the invention, the front and mesial portions of the liner 110 are more consistent with the shape of the mating femoral component than other portions of the liner. As shown in FIG. 60, the medial insert 110 also comprises peripheral steps 117a, 117b. 61 and 63 illustrate a locking mechanism 112 that is used to secure the medial insert 110 to the tibial support.

[00160] As shown in Figs. 62-63 and 92-93, the mesial edge 118 is raised relative to other portions and contours of the liner 120. As shown in Fig. 63, which illustrates the sagittal section of the liner 110, passing through its middle section, raised mesial the edge 118 extends from the front to the rear portion of the liner 110. In some embodiments of the invention, the mesial edge 118 provides resistance to lateral movement of the femur and prevents collision between the femoral component 400 and the intercondylar elevation 222 of the tibia howling bones. The height of the mesial edge can be chosen so as to provide the desired level of resistance, while the greater the height, the greater the resistance. As shown in the drawings relating to these options, the height of the mesial edge relative to other sections of the liner 110 is gradually reduced in the front-rear direction. In the embodiments depicted in FIGS. 62-63 and 92-93, the outer sides (at the beveled edge 119) of the medial insert 110 are substantially flat and have little or no fit to the condylar articular surfaces of the femur. In some embodiments of the invention, the maximum height of the mesial edge 118 is from about (0.063 cm) 0.025 inches to about (0.32 cm) 0.125 inches relative to the substantially flat outer sides. In some embodiments of the invention, the maximum height of the mesial edge 118 for the medial insert 118 is from about (0.09 cm) 0.035 inches to about 0.17 cm (0.065 inches).

[00161] Figs. 64-67 illustrate graphically and visually the kinematics of the medial and lateral inserts 110, 120 shown in Figs. 54-63, when used with other components, such as the femoral component 400 and the patellar component 600, in certain arthroplasty procedures . Using computer simulations using LifeMOD ™ software, the inventors found that creating a mesial edge 118 on the medial tibial insert 110 prevents lateral displacement of the femoral component 400 under the lateral forces acting on the femoral component 400 from the patella because of the presence of the quadriceps angle (angle Q). In some embodiments of the invention, where the mesial edge 118 is missing, the femoral component 400 can laterally shift when bent due to a shift in the patella, creating an environment in which the medial condyle 408 approaches too close to the attachment point of the posterior cruciate ligament 320 and the surrounding bone 220 , 222. In addition to improving the overall performance of the prosthesis compared to known designs, in some embodiments of the invention, the raised mesial edge 118 provides additional tibio-fe moral contact when the leg is extended. In some embodiments of the invention, it is provided that the medial insert 110 comprises a mesial edge 118 and the lateral insert 120 does not contain a mesial edge 128, although mesial edges 118, 128 may be present on both inserts 110, 120 for further stabilization.

[00162] FIGS. 64-66 graphically illustrate, respectively, medial approach, lateral approach and external rotation of the femoral implant 400 that is used with the implant 100 shown in FIGS. 38-46. Some embodiments of the invention may be opposed to at least some previous designs involving the preservation of both cruciate ligaments, in which, in areas adjacent to the femoral component, the coronal profiles were excessively fitted to the midline and outer peripheral sides of the tibial insert. This overfitting in some known constructions negatively restrained the internal-external rotation of the femoral component and reduced or eliminated its translational movement in the medial-lateral direction. At least some of the known constructions also differed in a significant degree of fitting of the front and rear sections of the liner, which negatively limited the rotation of the femur during extension and bending of the knee. The construction shown in FIG. 68 generally provides only a coronal fit to the midline of the tibia, which gradually decreases as it approaches the posterior sides of the liner. Due to this reduction in the degree of fit, this design allows for more free internal and external rotation of the femoral component 400 and more accurately reproduces the kinematics of the conventional knee when bent when the femoral component 400 performs external rotation relative to the tibial prosthesis 100. In other embodiments, however, the degree of fitting of the insert may be relatively high, similar to the degree of fit in some known designs.

[00163] In some cases, tibial inserts 110 and / or 120 may provide for several different values of the angle of inclination back. In one embodiment of the invention, liners, such as 110 and / or 120, are thinned as they move back to various degrees, which makes it possible to effectively rotate articular surfaces by an angle of flexion-extension relative to the lower surfaces of liners 110, 120 and provides a greater inclination back. This possibility in some embodiments of the invention may allow the surgeon to selectively establish joint mobility with a bent knee. For example, several pairs of medial 110 and 120 lateral inserts may be provided, each of which differs from the others by tilting back a certain number of degrees from 1 to 4, for example, 2 degrees. Other options may include pairing the medial 110 and lateral 120 inserts, in which the backward inclination of the medial insert 110 is different from the backward inclination of the lateral insert 120. Such options, generally speaking, can allow you to adjust the flexion space without re-resection of the tibia 220. B The options described above also provide for the choice of thickness values for the medial 110 and lateral 120 inserts, which will ensure the necessary balance of the ligaments. Various combinations and configurations with liner thickness, tilt in the medial-lateral and anteroposterior direction can be used to take into account the specific anatomical needs of a given patient. The ability to choose from several values of thickness, tilt in the medial-lateral and anteroposterior direction can also be provided for the tibial support, providing the possibility of using these configurations with one insert.

[00164] In some embodiments of the invention, the configuration of the articular surface for the medial 110 and lateral 120 inserts can be achieved using one insert 500 (preserving the cruciate ligament), which, as shown in Fig, 71, 73, 75, 78, and 80 has concave medial and lateral articular surfaces. As shown in FIG. 80, the lateral portion 510 of the liner 500 may be thicker (in some embodiments of the invention approximately 2.5 mm thicker) than the medial portion to allow it to function with the femoral components 400 shown. The thicker lateral portion 510 in this particular embodiment reproduces the varus articular displacement in the femoral component 400.

[00165] In other embodiments, medial 110 and lateral 120 inserts may be provided, each of which has its own angle of inclination back or its own thickness, and they can be used in various combinations depending on the balance needs of the medial and lateral collateral ligaments. In some cases, several inserts 110, 120 of various sizes may be provided in the form of a surgical set of implants, in which the total angle between the lower plane of the individual insert 110, 120 and the corresponding articular surface is different for different inserts. This angle can increase or decrease in the anteroposterior direction, medial-lateral, or in both of these directions independently or in concert. Having a choice of several different backward angles may reduce the need for re-resection of the tibia 220.

[00166] FIGS. 56 and 68 illustrate an example of a convex lateral liner 120 that facilitates the external rotation of the femoral component 400 during flexion due to its lateral extension, wherein the medial condyle 408 of the femur is limited by the concave sagittal geometry of the medial liner 110, as provided for in some embodiments of the invention.

[00167] As another alternative to using the individual tibial inserts 110, 120, the tibial support 1500 shown in FIG. 88 may comprise monolithic articular surfaces integrally with it. In other embodiments, such as shown in FIG. 89, a tibial prosthesis 1600 may be provided, made of a material 1602 with a porous structure, such as a metal foam, in which the articular surfaces 1604, as separate parts or as a unit, are in the proximal region porous structure 1602, as shown in Fig. For example, articular surfaces 1604 may be made of solid metal, ceramic, polymer, coating, or other suitable material deposited on the proximal side of the porous structure. Application can be carried out using traditional fast fabrication techniques, such as selective laser sintering of SLS (SLS), electron beam welding of ELS (EBM), three-dimensional printing or stereolithography. Alternatively, the porous structure 1602 can be obtained by injection molding using polymers when a monolithic support 1600 with a porous structure 1602 and a joint surface 1604 of various materials are formed.

[00168] 3. The femoral components

[00169] Enhanced femoral components are also provided. For example, the femoral component 400 shown in Figs. 67-75 contains the medial condyle 408 and the lateral posterior condyle 406 having a posterior lateral beveled edge 404 (as shown, for example, in Figs. 68-69, 72-74). As shown in FIGS. 74-75, in some embodiments, the posterior lateral beveled edge 404 has a depth d of from about 1 to about 5 mm, more preferably from about 2 to about 4 mm, for example, about 2.8 mm, and angle Ф from about zero to about 25 degrees, more preferably from about 5 to about 15 degrees, for example, about 10 degrees, which allows a gap with the posterior lateral tissue, for example the hamstring, with strong bending the knee. The beveled edge 404 may serve as a reference point for the distance D to the proximal surface of the articulation with the bone, mating with the site of resection of the distal femur. The specified distance D may, for example, be from about 3 to about 20 mm, more preferably from about 8 to about 15 mm, for example, about 11 mm The distances d and D can increase proportionally or disproportionately depending on the increase in the size of the femoral component 400. In some embodiments of the invention, for example, for large sizes of the femoral component 400, an angle Φ of approximately 10 ° and a distance of D of approximately 11 mm can be used, then as with the smaller dimensions of the femoral component 400, a smaller distance D of approximately 10 mm may be used.

[00170] Similarly, the medial posterior condyle 408 may have on its inner surface a posterior lateral beveled edge 410 shown in FIGS. 74, 76, 79-81 with an angle ψ of from about 0 to about 10 degrees, more preferably from about 3 to about 7 degrees, for example about 5 degrees, as shown in FIG. Such a chamfered edge can be connected to another chamfered edge 470 extending around the inner sagittal radius of the medial posterior condyle 408, providing additional clearance with the intercondylar elevation 222 of the tibia and the posterior cruciate ligament 320, but not reducing the covered surface of the bone. In some embodiments of the invention, the posterior lateral beveled margin 470 begins immediately behind the portions of the femoral component 400 in contact with the patella and therefore cannot bend around the intercondylar regions 412 of the contact with the patella of the femoral component. Instead, the posterior lateral oblique edge 470 in the posterior portions of the medial condyle 408 of the femur may be more pronounced. The upper faces of the intercondylar elevation 222 of the tibia can also be beveled with bone cutters to prevent collision with the femoral component 400.

[00171] Fig. 94 shows a medial sagittal projection of the medial condyle 455 of the femoral component 450 in one embodiment. The medial posterior condyle 455 may have a posterior lateral beveled edge 470 on its inner surface. Figures 95a-95k show various coronal sections along lines AA to KK, respectively, of the image shown in Fig. 94 illustrating the posterior the lateral beveled edge 470. As shown in Figs. 95a-95k, the femoral component has a rounded edge 460 in the projection along the lines AA, JJ and KK, and a posterior lateral beveled edge 470 in the projection along the BB lines, CC, DD, EE, FF, GG, HH, II. The angle ψ of the posterior lateral beveled edge 470 is from about 15 to about 40 degrees in some embodiments of the invention.

[00172] As shown in FIG. 68, the leading edge of the femoral component 400 may have a front-lateral beveled edge 402 on the lateral and / or medial sides to reduce the tension of the tissue of the retainer, which may be similar to some known designs of the femoral components.

[00173] In the exemplary embodiments of the invention described above with reference to the relevant drawings, various modifications may be made without departing from the scope of the present invention. In this regard, the entire contents of the preceding description and the accompanying drawings should be considered as material provided for illustrative and not restrictive purposes. For example, the new properties of the tibial inserts disclosed herein can easily be applied to instruments such as fitting implants for the tibial inserts, as well as to implants designed specifically for placement. Thus, the scope and content of the invention cannot be limited by any of the examples described above and should be determined only in accordance with the following claims and their equivalents. In addition, it is contemplated that one of ordinary skill in the art may use any or all of the features disclosed in the above embodiments in any suitable combination or sequence.

Claims (17)

1. Tibial prosthesis for at least partial replacement of the proximal tibia, containing:
(a) the medial portion of the support, the lateral portion of the support and the connecting portion of the support extending between the medial portion of the support and the lateral portion of the support and connecting these portions;
(b) a lower surface for contacting with the resected surface on the proximal tibia; and
(c) a keel for entry into a cavity formed in the proximal tibia, extending from the indicated lower surface at an angle in the lower-rear direction and having a front portion of the keel, a medial portion of the keel and a lateral portion of the keel; while the anterior portion of the keel passes along the connecting portion of the support in the direction from the anterior-medial to the posterior-lateral. 2. The tibial prosthesis according to claim 1, in which the front portion of the keel departs from the specified lower surface at an angle in the lower rear direction. 3. The tibial prosthesis according to claim 2, wherein at least a portion of the medial portion of the keel extends substantially in the anteroposterior direction on the medial portion of the support; and at least a portion of the lateral portion of the keel extends substantially in the anteroposterior direction on the lateral portion of the support. 4. The tibial prosthesis according to claim 3, in which the anterior portion of the keel is connected to the medial and lateral sections of the keel by sections of increased thickness. 5. The tibial prosthesis according to claim 3, wherein the anterior portion of the keel is connected to the medial and lateral portions of the keel by sections of increased width. 6. The tibial prosthesis according to claim 3, in which the thickness of the connecting portion of the support increases in the anteroposterior direction. 7. The tibial prosthesis according to claim 3, in which the height of the medial and lateral sections of the keel decreases along their length in the anteroposterior direction. 8. The tibial prosthesis according to claim 2, wherein the front portion of the keel has a front surface and a rear surface, the front surface extending from the specified lower surface in front at an angle in the lower rear direction; and the rear surface departs from the specified lower surface from the rear in the lower rear direction. 9. The tibial prosthesis according to claim 2, wherein a central cut is made that extends between the medial and lateral portions of the support behind the connecting portion of the support, said central cut having sufficient width and length to accommodate a portion of the intercondylar elevation of the tibia, including the anterior cruciate ligament and the site of attachment of the posterior cruciate ligament. 10. Tibial prosthesis for at least partial replacement of the proximal tibia, containing the articular surface of the tibia for articulation with the articular surface of the condyle of the femur, in which the specified articular surface of the tibia defines the mesial edge extending in the front-back direction along the mesial edge of the specified articular surface; wherein said mesial edge is raised relative to the corresponding central portion of said articular surface; wherein the height by which the mesial edge is raised relative to the corresponding central portion decreases in the anteroposterior direction. 11. The tibial prosthesis according to claim 10, wherein the articular surface of the tibia is the medial articular surface of the tibia and at least a portion of said medial articular surface of the tibia is concave in the sagittal plane. 12. The tibial prosthesis according to claim 11, wherein the antero-mesial portion of the medial articular surface of the tibia is bent so as to at least partially match the shape of the articular surface of the femoral condyle. 13. The tibial prosthesis according to claim 12, wherein the posterior-outer portion of the medial articular surface of the tibia is substantially flat and substantially does not match the shape of the articular surface of the femoral condyle. 14. The tibial prosthesis according to claim 10, in which the articular surface of the tibia is the lateral articular surface of the tibia, wherein said lateral articular surface of the tibia is convex in the sagittal plane. 15. The tibial prosthesis according to claim 14, wherein the antero-mesial portion of said lateral articular surface of the tibia is bent so as to at least partially match the shape of the articular surface of the femoral condyle. 16. The tibial prosthesis according to claim 15, wherein the posterior-outer portion of the lateral articular surface of the tibia is substantially flat and substantially does not correspond to the shape of the articular surface of the femoral condyle. 17. The tibial prosthesis according to claim 10, which is a tibial insert having a lower surface containing at least one fixing element for attachment to the tibial support.

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