Reinforcement element for a knee prosthesis

Abstract

A reinforcing element for a knee prosthesis comprises a generally frustoconical metal body configured to be inserted into a bone end and having an outer surface comprising a trabecular metal surface. The metal body is hollow with an axial through cavity defining a plurality of generally annular cross sections. The metal body is tilted in a tilted direction such that at least one eccentricity is defined between a first cross section at a first end of the axial through cavity and a second cross section at a second end of the axial through cavity. The reinforcing element further comprises a plurality of through slits in the metal body, opening from the first end to an intermediate portion of the metal body, the plurality of through slits being configured for radial compression of the metal body, locally reducing the circumference of the generally annular cross sections and increasing the press fit towards the bone portion during insertion of the reinforcing element.

Description

[0001] This application is a divisional application of Chinese Patent Application No. 202180040299.1, filed on July 5, 2021, entitled "Reinforcing Element for Prostheses, Particularly for Knee Prostheses," which is based on International Application PCT / EP2021 / 068511 and claims priority to Italian Patent Application No. 102020000016288, filed on July 6, 2020, which is incorporated herein by reference in its entirety. Technical Field

[0002] The present invention relates to a reinforcing element for a prosthesis, comprising a generally truncated cone-shaped metal body configured to be inserted into the end of a bone.

[0003] This invention is particularly useful in surgical interventions involving knee prosthesis implantation, and is described below with reference to this particular field of application to simplify its description.

[0004] Generally speaking, it is not excluded that the present invention can be applied to other types of surgical interventions involving the implantation of prostheses at the ends of bones. Background Technology

[0005] In orthopedic surgery for implanting prostheses, the bone seat is sometimes subjected to the application of reinforcing elements, which are typically applied to a shell milled into the bone to the desired contour.

[0006] In the context of this specification, the term "reinforcing element" refers to a prosthetic element capable of filling or replacing bone portions that have been cut or degenerated due to pre-existing lesions or implants, and also capable of connecting to further prosthetic joint elements to provide stable implantation.

[0007] When the spongy parts of the bone cannot support the prosthesis on their own, especially in the case of knee or hip prostheses, the use of reinforcing elements is particularly common.

[0008] Typically, reinforcing elements are roughly conical or truncated conical components made of metal.

[0009] For example, knee prostheses typically include a femoral component fixed to the distal femur and a tibial component fixed to the proximal tibia. In this case, either a reinforcing element for the distal femur or a reinforcing element for the distal tibia can be provided.

[0010] Document WO2015 / 145348(A1) relates to a multilayer reinforcement element for a prosthesis, comprising an axial cavity with openings at both ends and a truncated conical body with an annular cross-section. The body includes an outer portion of a metal beam material.

[0011] Document US2019 / 070008(A1) relates to a reinforcing element for a prosthesis, comprising a hollow sleeve having an internal channel passing through it. The hollow sleeve includes one or more bent joints configured to compress the channel and reduce the circumference and width of the hollow sleeve. The body is made of metallic material and has no beam section.

[0012] One difficulty in the prior art is that known reinforcing elements do not correspond precisely to bone anatomy, resulting in unsatisfactory performance of implanted prostheses.

[0013] In particular, because both the tibia and femur have asymmetrical, elongated structures, known reinforcing elements cannot be matched to the specific tibial or femoral anatomy of a patient.

[0014] Furthermore, in the existing technology, there are issues regarding the insertion or removal of reinforcing elements in the corresponding bone support, which involves surgical complexity or difficulty.

[0015] The general objective of this invention is to provide surgeons with an enhancement element that addresses some of the shortcomings of the prior art.

[0016] Another objective of this invention is to allow reinforcing elements to better adapt to specific bone anatomy.

[0017] Another object of the present invention is to provide a reinforcing element that is particularly suitable for a patient’s specific tibial or femoral anatomy.

[0018] Another object of the present invention is to provide a reinforcing element that can be inserted into or removed from a corresponding bone support more efficiently. Summary of the Invention

[0019] The present invention provides a reinforcing element for a prosthesis configured for insertion into the distal end of a bone, having a generally truncated metal body with an axial cavity. The metal body has a plurality of annular cross-sections defined along the axial cavity, these annular cross-sections being eccentrically stacked to define the overall tilt of the metal body. The construction of the metal body allows for better adaptation to specific bone anatomy, particularly for femoral or tibial applications. Furthermore, a trabecular metal surface, preferably integrally formed and seamlessly integrated with the metal body, can be provided to further improve implantation and attachment at the bone seat.

[0020] Based on this solution concept, a reinforcing element for prostheses, particularly for knee joint prostheses, is provided. This reinforcing element comprises a generally truncated cone-shaped metal body configured for insertion into the bone end. The metal body has an outer surface, which preferably includes a trabecular metal surface. The metal body is hollow, having axial cavities defining a plurality of generally annular cross-sections. Furthermore, the metal body is inclined in an inclined direction to define at least one eccentricity between a first cross-section at a first end of the axial cavity and a second cross-section at a second end of the axial cavity.

[0021] Therefore, a reinforcing element is provided that is particularly suitable for specific asymmetrical bone anatomy structures, with particular advantages when the reinforcing element is applied to the distal tibia or femur.

[0022] A reinforcing element for the prosthesis is also provided, comprising a generally frustoconical metal body having an axial cavity and including a metal beam surface. Preferably, the reinforcing element further comprises a plurality of through slits opening from a first end of the metal body to a middle portion; such slits are configured to provide radial compression of the metal body, thereby locally reducing the perimeter of the generally annular cross-section of the metal body.

[0023] Therefore, it advantageously provides a more effective reinforcing element during insertion and implantation, allowing radial compression of the metal body, which increases the compressive fit towards the bone; as the compressive fit to the bone increases, the pressure of the trabecular surface on the bone also increases, thereby stimulating bone growth to ensure stable and long-term connection.

[0024] The reinforcing element according to the invention advantageously improves both primary and secondary stability of the implant. Primary stability is the stability that can be immediately observed during intervention, which is essentially mechanical wedging. Conversely, secondary stability is achieved due to osseointegration, which is improved by the presence of primary stability, the presence of trabecular structure or sufficient porosity, and the presence of compressive forces or pressure fitting that stimulate bone growth.

[0025] In addition, specific features of the reinforcing element are provided, which makes it particularly effective when applied to the distal tibia or femur, as will be described in detail below.

[0026] Further features and advantages of the invention will become apparent from the following detailed description, provided for illustrative and non-limiting purposes, and from the claims that form an integral part of this specification. Attached Figure Description

[0027] - Figure 1 A perspective view of a first embodiment of a reinforcing element for a prosthesis according to the present invention is shown.

[0028] - Figure 2A front view of a first embodiment of a reinforcing element for a prosthesis is shown.

[0029] - Figure 3 A side sectional view of a first embodiment of a reinforcing element for a prosthesis is shown.

[0030] - Figure 4 A side view of a first embodiment of a reinforcing element for a prosthesis is shown.

[0031] - Figure 5 A front sectional view of a first embodiment of a reinforcing element for a prosthesis is shown.

[0032] - Figure 6 A bottom view of a first embodiment of a reinforcing element for a prosthesis is shown.

[0033] - Figure 7 A front view of a first embodiment of a reinforcing element for a prosthesis with further geometric indications is shown.

[0034] - Figure 8 A side view of a first embodiment of a reinforcing element for a prosthesis with further geometric indications is shown.

[0035] - Figure 9 A perspective view of a second embodiment of a reinforcing element for a prosthesis according to the present invention is shown.

[0036] - Figure 10 A front view of a second embodiment of the reinforcing element for a prosthesis is shown.

[0037] - Figure 11 A side sectional view of the reinforcing element used in the prosthesis is shown.

[0038] - Figure 12 A side view of a second embodiment of the reinforcing element for a prosthesis is shown.

[0039] - Figure 13 A front sectional view of a second embodiment of the reinforcing element for the prosthesis is shown.

[0040] - Figure 14 A front view of a second embodiment of a reinforcing element for a prosthesis with further geometric indications is shown.

[0041] - Figure 15 A side view of a second embodiment of a reinforcing element for a prosthesis with further geometric indications is shown.

[0042] - Figure 16 A perspective view of a third embodiment of a reinforcing element for a prosthesis according to the present invention is shown.

[0043] - Figure 17A front view of a third embodiment of the reinforcing element for a prosthesis is shown.

[0044] - Figure 18 A side sectional view of a third embodiment of the reinforcing element for the prosthesis is shown.

[0045] - Figure 19 A side view of a third embodiment of the reinforcing element for the prosthesis is shown.

[0046] - Figure 20 A front sectional view of a third embodiment of the reinforcing element for the prosthesis is shown.

[0047] - Figure 21 A front view of a third embodiment of a reinforcing element for a prosthesis, with further geometric indications, is shown.

[0048] - Figure 22 A side view of a third embodiment of a reinforcing element for a prosthesis with further geometric indications is shown.

[0049] - Figure 23 A top view of a third embodiment of the reinforcing element for the prosthesis is shown.

[0050] - Figure 24 A perspective view of a fourth embodiment of a reinforcing element for a prosthesis according to the present invention is shown.

[0051] - Figure 25 A front view of a fourth embodiment of the reinforcing element for a prosthesis is shown.

[0052] - Figure 26 A side sectional view of a fourth embodiment of the reinforcing element for the prosthesis is shown.

[0053] - Figure 27 A side view of a fourth embodiment of the reinforcing element for a prosthesis is shown.

[0054] - Figure 28 A front sectional view of a fourth embodiment of the reinforcing element for a prosthesis is shown.

[0055] - Figure 29 A top view of a fourth embodiment of the reinforcing element for a prosthesis is shown.

[0056] - Figure 30 A front view of a fourth embodiment of a reinforcing element for a prosthesis with further geometric indications is shown.

[0057] - Figure 31 A side view of a fourth embodiment of a reinforcing element for a prosthesis with further geometric indications is shown.

[0058] - Figure 32A perspective view showing a variant of a fourth embodiment of the reinforcing element for a prosthesis.

[0059] - Figure 33 A further perspective view of a variant of a fourth embodiment of the reinforcing element for a prosthesis is shown.

[0060] - Figure 34 An example of the application of a second embodiment of the reinforcing element for a prosthesis in the distal femur is shown.

[0061] - Figure 35 An example of the application of a third embodiment of the reinforcing element for a prosthesis in the distal tibia is shown.

[0062] In different accompanying drawings, similar elements will be indicated by similar reference numerals.

[0063] The technical drawings shown in the figure should be understood as purely illustrative drawings, and are not necessarily drawn to scale or have the same scale as each other. Detailed Implementation

[0064] Figure 1 A perspective view of a first embodiment of a reinforcing element 100 for a prosthesis according to the present invention is shown. The reinforcing element 100 in this example is an element for femoral application in combination with a knee prosthesis.

[0065] The reinforcing element 100 includes a generally truncated cone-shaped metal body 101 configured to insert into the distal femur. Preferably, the metal body 101 is made of titanium or an alloy thereof for biomedical applications.

[0066] Typically, a metallic body includes walls, which will be further described as having a substantially constant thickness.

[0067] The metal body 101 has an outer surface including a metal beam surface 102; preferably, the metal beam surface 102 is obtained seamlessly and integrally with the metal body 101 through a co-manufacturing process, such as EBM (electron beam processing) technology. In fact, the co-manufacturing process allows for the provision of an interface-free metal beam surface, thereby avoiding the risk of beam separation from the metal body.

[0068] The metal body 101 preferably includes a smooth edge 103 on the outer surface of the metal beam surface 102 on one or more sides, preferably on all sides.

[0069] The metal body 101 is hollow and has an axial cavity 104 that defines a plurality of generally annular cross sections, the construction of which will be described further.

[0070] Figure 2A front view of the reinforcing element 100 for the prosthesis is shown, in which the two symmetrical sidewalls of the reinforcing element have the same inclination.

[0071] Figure 3 The reinforcing element 100 for the prosthesis is shown relative to Figure 2 Side sectional view of section III-III.

[0072] The metal body 101 is inclined in the tilting direction, in this case facing to the right of the figure, so as to define the eccentricity between the first cross section at the first end 105 of the axial cavity 104 and the second cross section at the second end 106 of the axial cavity 104.

[0073] Specifically, the axial cavity 104 has a longitudinal axis 107 that is inclined in an inclined direction relative to the vertical axis of the metal body 101. For simplicity, the vertical axis, not shown in the figure, is perpendicular to one of the first or second cross-sections at the respective ends 105 or 106.

[0074] The metal body 101 includes a front wall 108 extending toward an inclined direction and a rear wall 109 opposite to the front wall 108 and extending away from the inclined direction.

[0075] The inclination of the front wall 108 relative to the vertical axis is less than that of the rear wall 109.

[0076] In other words, the outline of the metal body 101 gradually tapers towards the first end 105, and the front asymmetry can be seen in the side sectional view.

[0077] Figure 4 A side view of the reinforcing element 100 for the prosthesis is shown, indicating the details regarding... Figure 3 Some features that have already been discussed.

[0078] Figure 5 The reinforcing element 100 for the prosthesis is shown relative to Figure 4 The front sectional view of section VV.

[0079] In this embodiment, considering Figure 3 The direction shown is transverse to the tilt direction, which can be understood as how the longitudinal axis 107 of the cavity 104 is not tilted relative to the vertical axis of the metal body 101.

[0080] The reinforcing element 100 also includes a plurality of through slits 110 in the metal body 101, which open from the first end 105 to the middle portion of the metal body 101.

[0081] These slits 110 are configured for radial compression of the metal body 101, particularly facilitating insertion into the femoral head cavity, locally reducing the perimeter of the generally annular cross-section constituting the metal body 101 during insertion of the reinforcing element 100, and increasing the compression fit toward the bone portion.

[0082] Specifically, for the femoral application, the first cross-section at end 105 is smaller than the second cross-section at end 106 to facilitate the insertion of the metal body 101 into the femoral end.

[0083] Preferably, each slit 110 opens toward the first end 105 and terminates in a corresponding enlarged circular hole 111 adjacent to the middle portion of the metal body 101. Thus, the enlarged circular hole 111 is configured to increase the local mechanical resistance of the metal body.

[0084] Figure 6 A bottom view of the reinforcing element 100 for the prosthesis is shown. In this view, the eccentricity 112 generated between the first cross-section (in this case, annular) at the first end 105 and the second cross-section (in this case, annular) at the second end 106 of the axial cavity 104 can be understood.

[0085] Figure 7 A front view of a reinforcing element 100 for a prosthesis, with geometric indications relating to a metal body 101, is shown.

[0086] Specifically, the taper 113 of the symmetrical sidewalls is generally 6° to 10°, more preferably equal to 8.5°.

[0087] Figure 8 A side view of a reinforcing element 100 for a prosthesis, with geometric indications relating to a metal body 101, is shown.

[0088] In the example of reinforcing element 100, the front wall 108 is vertical and tilted at 0° relative to the vertical direction. Typically, the tilt of the front wall 108 relative to the vertical axis is 0° to 5°, more preferably 0° to 2°.

[0089] In the example of reinforcing element 100, the rear wall 108 has an inclination 114 of 8.5° relative to the vertical direction. Typically, the inclination of the rear wall 108 relative to the vertical axis is 6° to 10°.

[0090] Figure 9 A perspective view of a second embodiment of a reinforcing element 200 for a prosthesis according to the present invention is shown. The reinforcing element 200 in this example is an element used in combination with a knee prosthesis for femoral applications.

[0091] The reinforcing element 200 includes a generally truncated cone-shaped metal body 201 configured for insertion into the distal femur. Preferably, the metal body 201 is made of titanium or an alloy thereof for biomedical applications.

[0092] The metal body 201 has an outer surface including a metal beam surface 202; preferably, the metal beam surface 202 is directly applied to the metal body 201 in an integrated, seamless co-manufacturing process, for example, EBM (electron beam processing) technology.

[0093] The metal body 201 preferably includes a smooth edge 203 on one or more sides, preferably on all sides, surrounding the outer surface of the metal beam surface 202.

[0094] The metal body 201 is hollow and has an axial cavity 204 that defines multiple generally annular cross sections, the structure of which will be described further.

[0095] Figure 10 A front view of the reinforcing element 200 for the prosthesis is shown, in which a pair of bicondylar supports 220a and 220b arranged laterally in the metal body 201 are clearly visible.

[0096] The bicondylar supports 220a and 220b protrude from the end cross section of the metal body 201, and each support includes a tapered body that widens away from the metal body 201.

[0097] Preferably, the bicondylar supports 220a and 220b also have an outer surface including a metal beam surface, which is integrally and seamlessly formed with the bicondylar supports 220a and 220b.

[0098] In the reinforcing element 200, if the bone defect also extends to the femoral condyle, the bicondylar supports 220a and 220b also perform a supporting function for the femoral condyle. The choice between embodiment 100 without bicondylar supports and embodiment 200 with a bicondylar support including reinforcing elements can depend, for example, on the location and extension of the bone defect. For example, in the case of removal of a stemmed implant, a femoral defect is typically created along the channel, for which the reinforcing element 100 according to the first embodiment is preferred; in contrast, in the case of late bone degeneration, where the femoral condyle may not be able to provide sufficient support for the prosthesis, the reinforcing element 200 according to the second embodiment is preferred to obtain greater reinforcement in that area.

[0099] Preferably, the metal body includes a smooth edge 203 on its outer surface that at least partially surrounds the surface 202 of the metal beam, and preferably also surrounds the surface of the metal beam of the bicondylar supports 220a and 220b.

[0100] Figure 11 The reinforcing element 200 for the prosthesis is shown relative to Figure 10 The side sectional view of section XI-XI.

[0101] The metal body 201 is inclined in the tilting direction, in this case facing to the right of the figure, so as to define the eccentricity between the first cross section at the first end 205 of the axial cavity 204 and the second cross section at the second end 206 of the axial cavity 206.

[0102] Specifically, the axial cavity 204 has a longitudinal axis 207 that is inclined in an inclined direction relative to the vertical axis of the metal body 201. For simplicity, the vertical axis, not shown in the figure, is perpendicular to one of the first or second cross-sections at the respective ends 205 or 206.

[0103] The metal body 201 includes a front wall 208 extending toward an inclined direction and a rear wall 209 that is opposite to the front wall 208 and extends away from the inclined direction.

[0104] The inclination of the front wall 208 relative to the vertical axis is less than that of the rear wall 209.

[0105] In other words, the outline of the metal body 201 gradually tapers towards the first end 205, and the front asymmetry can be seen in the side sectional view.

[0106] In fact, the eccentricity between the first cross-section at the first end 205 and the second cross-section at the second end 206 of the axial cavity 204 can be guessed.

[0107] Figure 12 A side view of the reinforcing element 200 for the prosthesis is shown, indicating the details regarding... Figure 11 Some features that have already been discussed.

[0108] Figure 13 The prosthesis reinforcement element 200 is shown relative to Figure 12 Front sectional view of section XIII-XIII.

[0109] The reinforcing element 200 also includes a plurality of through slits 210 in the metal body 201, which open from the first end 205 to the middle portion of the metal body 201.

[0110] These slits 210 are configured for radial compression of the metal body 201, particularly facilitating insertion into the femoral head cavity, locally reducing the perimeter of the generally annular cross-section constituting the metal body 201 during insertion of the reinforcing element 200, and increasing the compression fit toward the bone portion.

[0111] Specifically, for the femoral application, the first cross-section at end 205 is smaller than the second cross-section at end 206 to facilitate the insertion of the metal body 201 into the femoral end.

[0112] Preferably, each slit 210 opens toward the first end 205 and terminates in a corresponding enlarged circular hole 211 adjacent to the middle portion of the metal body 201. Thus, the enlarged circular hole 211 is configured to increase the local mechanical resistance of the metal body.

[0113] In the reinforcing element 200 for use in the femur, the first cross-section at end 205 is smaller than the second cross-section at end 206, and a pair of laterally arranged bicondylar supports 220a and 220b protrude precisely from the second cross-section, so that when the reinforcing element is implanted into the corresponding femoral cavity, it is in a distal position.

[0114] Figure 14 A front view of the reinforcing element 200 for the prosthesis is shown, with geometric indications in relation to the metal body 201.

[0115] Specifically, the taper 213 of the sidewall is generally 6° to 10°, more preferably equal to 8.5°, as in the example of the reinforcing element 200.

[0116] As shown in the figure, the second cross-section at end 206 is further inclined along a second inclined direction, which lies in a plane transverse to the inclined direction of the longitudinal axis 207. In this sense, the metal body 201 has an inclined plane at end 206 that differs from the inclined plane at end 205, thus creating an overall asymmetry of the reinforcing element 201 not only in the already considered frontal inclined direction but also in the transverse inclined direction of the entire metal body 201, such as... Figure 14 As shown.

[0117] Furthermore, the pair of bicondylar supports 220a and 220b extend from the second end 206 to the same height 221, thereby defining a pair of asymmetrical bicondylar supports 220a, 220b.

[0118] Given the overall asymmetry of the reinforcing element 200, it is clear that different solutions must be provided for the left or right femur.

[0119] Figure 15 A side view of the reinforcing element 200 for the prosthesis is shown, with geometric indications in relation to the metal body 201.

[0120] In the example of reinforcing element 200, the front wall 208 is vertical and inclined at 0° relative to the vertical direction. Typically, the inclination of the front wall 208 relative to the vertical axis is 0° to 5°, more preferably 0° to 2°.

[0121] In the example of reinforcing element 200, the rear wall 209 has an inclination 214 of 8.5° relative to the vertical axis. Typically, the inclination of the rear wall 209 relative to the vertical axis is 6° to 10°.

[0122] Figure 16 A perspective view of a third embodiment of a reinforcing element 300 for a prosthesis according to the present invention is shown. This example of a reinforcing element 300 is an element used in combination with a knee prosthesis for tibial applications.

[0123] The reinforcing element 300 includes a generally truncated cone-shaped metal body 301 configured to insert into the distal end of the tibia. Preferably, the metal body 301 is made of titanium or an alloy thereof for biomedical applications.

[0124] The metal body 301 has an outer surface including a metal beam surface 302; preferably, the metal beam surface 302 is directly applied to the metal body 301 in an integrated, seamless co-manufacturing process, for example, EBM (electron beam processing) technology.

[0125] The metal body 301 preferably includes a smooth edge 303 on the outer surface of the metal beam surface 302 on one or more sides, preferably on all sides.

[0126] The metal body 301 is hollow and has an axial cavity 304 that defines a plurality of generally annular cross sections, the construction of which will be described further.

[0127] In a natural analogy, the metal body 301 resembles a corolla shape, in which two opposing petals have been removed.

[0128] Figure 17 A front view of the reinforcing element 300 for the prosthesis is shown, illustrating that the two symmetrical sidewalls of the reinforcing element have the same inclination and construction.

[0129] Figure 18 The reinforcing element 300 for the prosthesis is shown relative to Figure 17 The side sectional view of section XVIII-XVIII.

[0130] The metal body 301 is inclined in the tilting direction, in this case facing to the right of the figure, so as to define the eccentricity between the first cross section at the first end 305 of the axial cavity 304 and the second cross section at the second end 306 of the axial cavity 302.

[0131] Specifically, the axial cavity 304 has a longitudinal axis 307 that is inclined in an inclined direction relative to the vertical axis of the metal body 301. For simplicity, the vertical axis, not shown in the figure, is perpendicular to one of the first or second cross-sections at the respective ends 305 or 306.

[0132] The metal body 301 includes a front wall 308 extending toward an inclined direction and a rear wall 309 that is opposite to the front wall 308 and extends away from the inclined direction.

[0133] The inclination of the front wall 308 relative to the vertical axis is less than that of the rear wall 309.

[0134] In other words, the outline of the metal body 301 gradually tapers towards the second end 306, and the front asymmetry can be seen in the side sectional view.

[0135] Figure 19 A side view of the reinforcing element 300 for the prosthesis is shown, indicating the details regarding... Figure 18 Some features that have already been discussed.

[0136] For the tibia application, it can be seen that the first cross-section at end 305 is larger than the second cross-section at end 306, in order to facilitate the insertion of the metal body into the end of the tibia.

[0137] The reinforcing element 300 also includes a pair of cutouts 320 arranged laterally in the metal body 301 and opening from the first end 305 to the middle portion of the metal body 301.

[0138] Figure 20 The reinforcing element 300 for the prosthesis is shown relative to Figure 19 Front sectional view of section XX-XX.

[0139] In this embodiment, considering Figure 18 The direction shown is transverse to the tilt direction, which can be understood as how the longitudinal axis 307 of the cavity 304 is not tilted relative to the vertical axis of the metal body 301.

[0140] Figure 21 A front view of the reinforcing element 300 for the prosthesis is shown, with geometric indications in relation to the metal body 301.

[0141] Preferably, the metal body 301 includes a sidewall 321 at the incision 320; such a sidewall 321 has a corresponding curvature and concavity relative to the outer side of the metal body 301 to replicate the medial / lateral and posterior bone anatomy.

[0142] Specifically, the overall taper 313 of the symmetrical sidewall 321 (measured relative to an imaginary straight line passing through the two edges of the metal body 301 at the first end 305 and the second end 306, respectively) is generally 12° to 20°, more preferably equal to 18°.

[0143] Figure 22 A side view of the reinforcing element 300 for the prosthesis is shown, with geometric indications in relation to the metal body 301.

[0144] In the example of reinforcing element 300, the front wall 308 is close to the vertical axis, and its inclination 315 relative to the vertical axis is equal to 2°. Typically, the inclination of the front wall 308 relative to the vertical axis can be from 0° to 5°, more preferably from 0° to 2°.

[0145] In the example of reinforcing element 300, the rear wall 309 is tilted at 16° relative to the vertical axis. Typically, the tilt of the rear wall 309 relative to the vertical axis is between 15° and 20°.

[0146] Preferably, the posterior wall 309 has a further curved and concave shape relative to the outer side of the metal body 301 to replicate the posterior tibial anatomy.

[0147] Figure 23 A top view of the reinforcing element 300 used in the prosthesis is shown.

[0148] In this view, the eccentricity 312 generated between the first cross-section (in this case, annular) at the first end 305 and the second cross-section (in this case, annular) at the second end 306 of the axial cavity 304 can be understood.

[0149] Figure 24 A perspective view of a fourth embodiment of a prosthesis reinforcement element 400 according to the present invention is shown. This example reinforcement element 400 is an element used in conjunction with a knee prosthesis for tibial applications.

[0150] The reinforcing element 400 includes a generally truncated cone-shaped metal body 401 configured to insert into the distal end of the tibia. Preferably, the metal body 401 is made of titanium or an alloy thereof for biomedical applications.

[0151] The metal body 401 has an outer surface including a metal beam surface 402; preferably, the metal beam surface 402 is applied directly to the metal body 401 by, for example, an integral and seamless co-manufacturing process using EBM (electron beam processing) technology.

[0152] The metal body 401 preferably includes a smooth edge 403 on one or more sides, preferably on all sides, surrounding the metal beam surface 402 on the outer surface.

[0153] The metal body 401 is hollow and has an axial cavity 404 that defines a plurality of generally annular cross sections, the structure of which will be described further.

[0154] Figure 25 A front view of a reinforcing element 400 for a prosthesis is shown, wherein the two symmetrical sidewalls 421 of the reinforcing element have the same inclination and construction.

[0155] Figure 26 The reinforcing element 400 for the prosthesis is shown relative to Figure 25 The side sectional view of section XVI-XVI.

[0156] The metal body 401 is inclined in the tilting direction, in this case facing to the right of the figure, so as to define at least one eccentricity between the first cross-section at the first end 405 of the axial cavity 404 and the second cross-section at the second end 406 of the axial cavity 404.

[0157] Specifically, the axial cavity 404 has a longitudinal axis 407 that is inclined in an inclined direction relative to the vertical axis of the metal body 401. For simplicity, the vertical axis, not shown in the figure, is perpendicular to one of the first or second cross-sections at the respective ends 405 or 406.

[0158] The metal body 401 includes a front wall 408 extending toward an inclined direction and a rear wall 409 that is opposite to the front wall 402 and extends away from the inclined direction.

[0159] The inclination of the front wall 408 relative to the vertical axis is less than that of the rear wall 409.

[0160] In other words, the outline of the metal body 401 gradually tapers towards the second end 406, and the front asymmetry can be seen in the side sectional view.

[0161] Figure 27 A side view of the reinforcing element 400 for the prosthesis is shown, indicating the details regarding... Figure 26 Some features that have already been discussed.

[0162] For the tibia application, it can be seen that the first cross-section at end 405 is larger than the second cross-section at end 406, in order to facilitate the insertion of the metal body into the end of the tibia.

[0163] The reinforcing element 400 also includes a pair of cutouts 420 arranged laterally in the metal body 401 and opening from the first end 405 to the middle portion of the metal body 401.

[0164] Figure 28 The reinforcing element 400 for the prosthesis is shown relative to Figure 27 Front sectional view of section XXVIII-XXVIII.

[0165] In this embodiment, considering the relationship with Figure 26 The direction shown is transverse to the tilt direction, which can be understood as how the longitudinal axis 407 of the cavity 404 is not tilted relative to the vertical axis of the metal body 401.

[0166] Figure 29A top view of the reinforcing element 400 for the prosthesis is shown, wherein it can be understood that the first cross-section at end 405 is a double-lobed annular shape, such that the outer surface of the metal body 401 is tapered between the first and second cross-sections, as... Figure 24 As shown.

[0167] Analogous to nature, the metal body 401 resembles a corolla shape, in which two opposing petals have been removed.

[0168] In this view, the double eccentricity 412 generated between the first cross section at the first end 405 of the axial cavity 404 (in this case, the double leaf therefore has two circumferential centers describing it) and the second cross section at the second end 406 (in this case, an annulus with only one circumferential center) can also be understood.

[0169] Figure 30 A front view of the reinforcing element 400 for the prosthesis is shown, with geometric indications of the metal body 401.

[0170] Preferably, the metal body 401 includes a sidewall 421 at the incision 420; such a sidewall 421 has a corresponding curvature and concavity relative to the outer side of the metal body 401 to replicate the medial / lateral and posterior bone anatomy.

[0171] Specifically, the overall taper 413 of the lateral symmetry wall 421 is generally 45° to 55°, more preferably equal to 50°.

[0172] Figure 31 A side view of the reinforcing element 400 for the prosthesis is shown, with geometric indications of the metal body 401.

[0173] In the example of reinforcing element 400, the front wall 408 is close to the vertical axis and has an inclination of 2° relative to the vertical axis. Typically, the inclination of the front wall 408 relative to the vertical axis can be from 0° to 5°, more preferably from 0° to 2°.

[0174] In the example of reinforcing element 400, the rear wall 409 is tilted at an angle of 19.4° relative to the vertical axis. Typically, the tilt of the rear wall 409 relative to the vertical axis is between 15° and 20°.

[0175] Preferably, the posterior wall 409 has a further curved and concave shape relative to the outer side of the metal body 401 to replicate the posterior tibial anatomy.

[0176] Figure 32 and 33 Perspective views of variant 400' of the reinforcing element used in the prosthesis are shown.

[0177] In this variant, the reinforcing element 400' includes a plurality of through slits 410 in the metal body, opening from a first end to a middle portion of the metal body. These slits are configured for radial compression of the metal body, locally reducing the circumference during insertion of the reinforcing element 400', and increasing the press fit toward the bone portion. Preferably, each slit 410 terminates in a corresponding enlarged circular hole 411.

[0178] Figure 34 An example of applying the reinforcing element 200 for the prosthesis to the distal femur is shown.

[0179] Figure 35 An example of applying the reinforcing element 300 of the prosthesis to the distal tibia is shown.

[0180] Obviously, those skilled in the art can further implement and modify this invention to meet occasional needs.

[0181] In particular, if there is no technical bias in this regard, the specific features described with reference to the embodiments can also be applied to variations of other embodiments described herein.

[0182] Therefore, the above embodiments should be understood as being provided for illustrative and non-limiting purposes.

Claims

1. A reinforcing element (100, 200, 400) for a knee joint prosthesis, comprising a generally truncated cone-shaped metal body (101, 201, 401), said metal body being configured to insert into a bone end and having an outer surface including a trabecular metal surface (102, 202, 402). The metal bodies (101, 201, 401) are hollow and have axial cavities (104, 204, 404) defining multiple generally annular cross-sections. in, The metal bodies (101, 201, 401) are inclined in an inclined direction such that at least one eccentricity (112, 412) is defined between a first cross-section at a first end (105, 205, 405) of the axial cavity (104, 204, 404) and a second cross-section at a second end (106, 206, 406) of the axial cavity (104, 204, 404), wherein the eccentricity between the first cross-section and the second cross-section is a lateral offset between the first cross-section and the second cross-section; The invention is characterized by further comprising a plurality of through slits (110, 210, 410) in the metal body (101, 201, 401), the through slits opening from the first end (105, 205, 405) to a middle portion on the metal body (101, 202, 401), wherein the plurality of through slits (110, 210, 410) are configured for radial compression of the metal body (101, 203, 401), locally reducing the circumference of the generally annular cross-section during insertion of the reinforcing element (100, 200, 400), and increasing the press fit toward the bone portion.

2. The reinforcing element according to claim 1, wherein the axial cavity (104, 204, 404) has a longitudinal axis (107, 207, 407) inclined in the inclined direction relative to the vertical axis of the metal body (101, 201, 401), the vertical axis being perpendicular to the first cross section or the second cross section.

3. The reinforcing element according to claim 2, wherein the metal body (101, 201, 401) includes a front wall (108, 208, 408) extending toward the inclined direction, and further includes a rear wall (109, 209, 409) opposite to and away from the front wall (108, 208, 408) extending away from the inclined direction, wherein the inclination of the front wall (108, 208, 408) with respect to the vertical axis is less than the inclination of the rear wall (109, 209, 409).

4. The reinforcing element of claim 1, wherein, for a femoral application, the first cross-section is smaller than the second cross-section to facilitate insertion of the metal body (101, 201) into the distal end of the femur.

5. The reinforcing element according to claim 1, wherein for tibial application, the first cross-section is larger than the second cross-section to facilitate insertion of the metal body (401) into the distal end of the tibia.

6. The reinforcing element according to claim 1, wherein each of the plurality of through slits (110, 210, 410) terminates in a corresponding enlarged circular hole (111, 211, 411) on the intermediate portion wall, the enlarged circular hole (111, 211, 411) being configured to improve the local mechanical resistance of the metal body (101, 201, 401).

7. The reinforcing element according to any one of claims 1 to 6, for use in the femur, wherein the first cross-section is smaller than the second cross-section, and further comprising laterally arranged bicondylar supports (220a, 220b) in the metal body (201), each of the bicondylar supports (220a, 220b) protruding from the second cross-section and comprising a tapered shape that widens away from the metal body (201).

8. The reinforcing element according to claim 7, wherein the bicondylar support (220a, 220b) has an outer surface including a metal beam surface, the metal beam surface of the bicondylar support being integrally seamless with the bicondylar support (220a, 220b).

9. The reinforcing element according to claim 7, wherein, The second cross section (206) is inclined in a second inclination direction transverse to the inclination direction, and the bicondylar supports (220a, 220b) extend from the second cross section (206) at the same height (221), thereby defining the bicondylar supports (220a, 220b) as asymmetrical.

10. The reinforcing element according to any one of claims 1 to 6, for tibial application, wherein the first cross-section is larger than the second cross-section, and wherein the metal body (401) includes a sidewall (421) having a correspondingly curved and concave shape relative to the tibia outside the metal body (401) to replicate the medial and posterior bone anatomy.

11. The reinforcing element according to claim 10, further comprising a pair of cutouts (420) disposed on the sidewall (421) and opening from the first end to the middle portion of the metal body (401).

12. The reinforcing element according to claim 10, wherein the first cross-section is bilobed and the second cross-section is annular, and the outer surface of the metal body (401) is tapered between the first cross-section and the second cross-section.

13. The reinforcing element according to any one of claims 1 to 6, wherein the metal body (101, 201, 401) includes a smooth edge (103, 203, 403) on the outer surface surrounding the surface of the metal beam (102, 202, 402).

14. The reinforcing element according to any one of claims 1 to 6, wherein the surface of the metal beam (102, 202, 402) is integrally and seamlessly formed with the metal body (101, 201, 401).

15. The reinforcing element according to any one of claims 1 to 6, wherein the metal body (101, 201, 401) comprises a wall (108, 208, 408; 109, 209, 409; 421) having a substantially constant thickness.

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