阅读说明：本技术 柔性多孔植入物固定系统 (Flexible porous implant fixation system ) 是由 J·亚当姆 B·戈贝伦 于 2018-12-18 设计创作，主要内容包括：本公开涉及柔性多孔植入物固定系统。某些方面提供了柔性多孔结构,其包括螺旋结构、以及被耦合到螺旋结构的多个互锁元件,螺旋结构被配置成连接多个互锁元件。某些方面提供了包括多孔结构的主体,主体被配置成垂直于骨的轴线地与骨接合；以及包括头部的螺钉,其中头部被配置成位于主体的容积内,而螺钉的一部分延伸远离主体,其中主体被配置成限制头部在主体内沿骨的轴线的移动。(The present disclosure relates to flexible porous implant fixation systems. Certain aspects provide a flexible porous structure comprising a helical structure, and a plurality of interlocking elements coupled to the helical structure, the helical structure configured to connect the plurality of interlocking elements. Certain aspects provide a body comprising a porous structure, the body configured to engage a bone perpendicular to an axis of the bone; and a screw comprising a head, wherein the head is configured to be located within the volume of the body and a portion of the screw extends away from the body, wherein the body is configured to limit movement of the head within the body along an axis of the bone.)

1. A flexible porous structure for implantation in bone, the structure comprising:

a helical structure; and

a plurality of interlocking elements coupled to the helical structure, the helical structure configured to connect the plurality of interlocking elements, wherein:

each interlocking element of the plurality of interlocking elements is configured to: when in the neutral position, there is a space between the interlocking element and the helical structure and there is a space between the interlocking element and an adjacent interlocking element, and

the plurality of interlocking elements are configured to: contacting the helical structure when a compressive force is applied to the flexible porous structure, thereby limiting compression of the helical structure, an

The plurality of interlocking elements are configured to: when an extension force is applied to the flexible porous structure, adjacent interlocking elements are contacted, thereby limiting extension of the helical structure.

2. The flexible porous structure of claim 1, wherein the helical structure and the plurality of interlocking elements form a surface of a hollow cylinder.

3. The flexible porous structure of claim 2, wherein each of the plurality of interlocking elements comprises a T-shaped structure, and wherein adjacent interlocking elements are oriented in mirror image of each other.

4. The flexible porous structure of claim 1, wherein the helical structure forms a surface of a cylinder, and wherein the plurality of interlocking elements are positioned inside the cylinder.

5. The flexible porous structure of any one of claims 2 to 4, wherein the flexible porous structure comprises a screw, wherein the helical structure comprises a housing of the screw.

6. The flexible porous structure of claim 5, further comprising threads formed on the housing.

7. The flexible porous structure of claim 6, wherein the thread is aligned with the helical structure.

8. The flexible porous structure of claim 6, wherein the threads form a cross-helical design with the helical structure.

9. The flexible porous structure of any one of claims 5 to 8, wherein the screw comprises an inner core comprising a plurality of sliding elements including a first sliding element coupled to the head of the screw and a second sliding element coupled to the tip of the screw, wherein:

the first and second sliding elements are configured to slide relative to each other along a longitudinal axis of the screw.

10. The flexible porous structure of any one of claims 5 to 8, wherein the helical structure comprises at least one strut comprising a sharp edge.

11. An implant fixation system comprising:

a body comprising a porous structure, the body configured to engage a bone perpendicular to an axis of the bone; and

a screw comprising a head, wherein the head is configured to be positioned within a volume of the body and a portion of the screw extends away from the body, wherein the body is configured to limit movement of the head within the body along the axis of the bone.

12. The implant fixation system of claim 11, further comprising a plug configured to receive the portion of the screw, wherein the plug is configured to be inserted in a hole formed in a bone.

13. The implant fixation system of claim 12, wherein the plug comprises an external feature configured to limit rotation of the plug in the bore.

14. The implant fixation system of any one of claims 11 to 13, wherein the head comprises a second porous structure.

Technical Field

The present disclosure relates to medical implants. More particularly, the present disclosure relates to flexible porous implant fixation systems.

Background

Porous or partially porous bone implants may be used in some instances. They may be made porous for various reasons, such as to reduce weight, reduce thermal conductivity, achieve mechanical properties closer to those of the surrounding bone, and/or allow bone ingrowth (ingrowth) for better fixation.

In designing bone implants to allow bone ingrowth for better fixation, implant designers are faced with conflicting requirements: on the one hand, the stiffness of the implant should be lower than that of the surrounding bone, on the other hand, the implant should be strong enough to resist accidental impacts.

In particular, implants that are harder than the surrounding bone may cause stress shielding. Stress shielding is a phenomenon in which the implant bears the majority of the load, so that a smaller portion of the load is borne by the bone. This may lead to bone resorption. In other words, the opposite of bone ingrowth may occur. To reduce the stiffness of porous implants, one strategy is to reduce the density of the porous structure.

However, porous structures with lower densities also typically have reduced strength. This is detrimental as it increases the risk of the implant breaking under accidental loading. To increase the strength of a porous implant, one strategy is to increase the density of its porous structure.

International patent application WO/2017/042366, incorporated herein in its entirety by reference, discloses (such as in the abstract of WO/2017/042366 and fig. 8b) a porous structure that allows to compromise two requirements: low stiffness under normal load and high stiffness under accidental load. In some embodiments, such as described in fig. 13C and in the specification of WO2017/042366, page 20, lines 15-21, the porous structure comprises cells connected by means of connecting elements. Such as described in the summary of the description of WO/2017/042366, each pair of adjacent elements has two surfaces which are in contact at greater than normal deformation. In this way, the connecting element may be dimensioned to provide the low stiffness required to promote bone ingrowth when the surfaces are not in contact, and the cells may be designed to provide the strength required to withstand accidental loading when the surfaces are in contact, such as described in the summary of the description of WO/2017/042366.

Further described herein are implants and porous structures that provide further novel and unobvious improvements to the implants and porous structures described in WO/2017/042366, such as described in the summary of the invention section of the specification of WO/2017/042366.

Drawings

Fig. 1 is an example of a porous structure having a body that is a helical rod (bar) with integrated interlocking elements, according to certain aspects.

Fig. 2 is an illustration of a porous structure having a body that is a zig-zag (zig-zag) shape with integrated interlocking elements, according to certain aspects.

Fig. 3 is an example of a porous structure having a body that is a perforated (perforated) plate with integrated interlocking elements, according to certain aspects.

Fig. 4 is an example of a porous structure having a body that is a perforated tube with integrated interlocking elements, according to certain aspects. In certain aspects, the body of fig. 4 may be an outer layer (skin) for an internal porous structure.

Fig. 5A is an example of five bodies of cells of a porous structure (e.g., porous cell bodies), according to certain aspects.

Fig. 5B is an example of an interlocking element of a porous structure according to certain aspects.

Fig. 5C is an illustration of a porous structured connecting element according to certain aspects.

Fig. 5D is an illustration of a complete porous structure formed by the elements of fig. 5A-5C, according to certain aspects.

Fig. 5E is an exploded view of an example of two units of a porous structure, each unit having a body and an interlocking element, according to certain aspects.

Fig. 6 is an exploded view of a hexagonal porous structure including two cells and flexible connecting elements according to certain aspects. In certain aspects, the porous structured flexible connecting element of fig. 6 can constitute an outer layer.

Fig. 7 is an illustration of two cells of a porous structure connected by a flexible connecting element, according to certain aspects.

Fig. 8 is an example of cells of a porous structure stacked to form a linear structure and connected by flexible connecting elements, according to certain aspects.

FIG. 9 is an example of porous units coupled to form a planar structure connected by flexible connecting elements, according to certain aspects.

FIG. 10 is an example of porous units stacked and coupled to form a 3D structure connected by flexible connecting elements, according to certain aspects.

Fig. 10A is an example of a spinal spacer formed from porous units stacked, coupled, and connected by a flexible connecting element, according to certain aspects.

Fig. 11 is an illustration of a screw having a helical porous structure, in accordance with certain aspects.

Fig. 12 is a cross-sectional view of an example of the screw of fig. 11. In certain aspects, the screw includes a screw head, a screw tip, a shell, and a central core.

Fig. 12A-12C illustrate an example screw including a flexible porous structure, and a strut configured to cut off ingrown bone.

Fig. 13 is an example of a rod (craft) having a screw formed as a cross-helical porous structure according to certain aspects.

Fig. 14A and 14B are examples of a porous structured separation unit for a rod of a screw or bolt according to certain aspects.

Fig. 14C is an example of the separation unit of fig. 14A and 14B in an interlocked position according to certain aspects.

Fig. 14D is an example of a helical connecting element having threads for the shank of a screw or bolt, according to certain aspects.

Fig. 14E is an example of a second helical connecting element for a rod of a screw or bolt according to certain aspects.

Fig. 14F is an example of a shank of a screw or bolt formed from the elements of fig. 14C-14E, according to certain aspects.

Fig. 15 is an illustration of a screw having two parallel helices as a porous structure, according to certain aspects.

Fig. 16 is an example of a glenoid implant including a porous structure according to certain aspects.

Fig. 17 is an example of a glenoid implant (e.g., for a large bone defect) including a porous structure according to certain aspects.

Fig. 18 is an example of a femoral implant including a porous structure according to certain aspects.

Fig. 19 is an illustration of a knee implant including a porous structure, according to some aspects.

Fig. 20 is an illustration of a dental implant including a porous structure according to certain aspects.

Fig. 21A is an illustration of a body of an implant for an implant fixation system for a bone including a porous structure (e.g., having a small cross-section), according to certain aspects.

Fig. 21B is an illustration of a bolt for an implant of an implant fixation system for a bone including a porous structure (e.g., having a small cross-section), according to certain aspects.

Fig. 21C is an illustration of a plug for an implant fixation system for a bone including a porous structure (e.g., having a small cross-section), according to certain aspects.

Fig. 21D is an illustration of an implant fixation system for a bone (e.g., having a small cross-section) including a porous structure formed by the elements of fig. 21A-21C, according to certain aspects.

Fig. 22 is a schematic view of a medical device of the prior art.

FIG. 23 is an example of a system for designing and manufacturing 3D objects.

FIG. 24 illustrates a functional block diagram of one example of the computer shown in FIG. 23.

Fig. 25 illustrates a high-level process for manufacturing a 3D object using an additive manufacturing system.

Detailed Description

The following description and the annexed drawings set forth in detail certain illustrative embodiments. The embodiments described in any particular context are not intended to limit the disclosure to the specific embodiments or to any particular use. One skilled in the art will recognize that the disclosed embodiments, aspects, and/or features are not limited to any particular embodiment. For example, in certain aspects, reference to "a" layer, component, portion, etc. may refer to "one or more.

Certain embodiments herein relate to implants having a reduced size compared to some other porous structures, having separate cell bodies, connecting elements, elements that come into contact upon large deformation (e.g., interlocking elements or deformation limiting elements), and an outer layer.

For example, certain embodiments herein provide a porous structure design that further improves the design in WO/2017/042366, such as the design described in fig. 13c of WO/2017/042366 and at page 20, lines 15-21 of the specification, or such as the design shown in any of fig. 1 a-7, fig. 10 a-17 b, or fig. 19 a-19 d, and described at page 9, line 31-page 15, line 18, page 17, line 14-page 23, line 16, or page 25, lines 4-28 of the specification). In particular, in certain embodiments, instead of a structure comprising individual units (such as described in fig. 13c of WO/2017/042366 and at page 20, lines 15-21 of the specification), which are connected by means of connecting elements and have interlocking or restraining elements that only come into contact upon large deformations, embodiments of the porous structures described herein combine elements of two or more of these elements to achieve a more compact design. One exemplary embodiment comprises one or more cells which themselves provide the flexible behavior of the connecting element in WO/2017/042366 (such as described in fig. 13c of WO/2017/042366 and at page 20, lines 15-21 of the specification), and which internally comprise two or more elements which limit the deformation and contribute to the mechanical strength. In other words, the body of the unit serves simultaneously as a connecting element and optionally even as an outer layer. The restraining element may be a decoupling element that contacts upon a degree of deformation, such as an opposing element for limiting compression and an interlocking element for limiting extension. The combination of limits on compression and extension may be achieved by designing the interlocking elements to contact each other when over extended and to contact the body of the unit when over compressed. Other embodiments are possible.

Example embodiments of such cells may have a spiral shape such as cell 100 (fig. 1), a zigzag shape such as cell 200 (fig. 2), a perforated structure such as cell 300 (fig. 3, e.g., honeycomb), a plate shape such as cell 200 or 300 (fig. 2 or 3), or a tube shape such as cell 100 or 400 (fig. 1 or 4). Other shapes such as three-dimensional structures, layered structures, auxetic structures, prismatic structures, wave-like designs, crimp designs, stepped designs, corrugated designs, etc. are also possible embodiments. Examples of the restriction elements 104, 204, 304, 404 are also shown in fig. 1-4.

Another exemplary embodiment combines the functionality of the outer skin and connecting element while maintaining an identifiable unit body. Examples of such embodiments can be seen in fig. 5 to 10.

Fig. 5A to 5E show an example in which the unit body 502 takes the shape of a perforated disc 502 (fig. 5A). Between the discs 502 are interlocking elements 504 (fig. 5B), the interlocking elements 504 being configured to interlock with each other and thereby removably couple the unit bodies 502. In each pair of interlocking elements 504, one interlocking element is attached to one unit body 502 of a pair of adjacent unit bodies 502 and the other interlocking element is attached to the other unit body 502 of the pair of adjacent unit bodies 502. Fig. 5E shows an exploded view with two unit bodies 502 and their interlocking elements 504. In this case, the interlocking elements 504 have a layered design with two layers 508, but other designs or designs with a single layer or more than two layers are possible. The layers 508 of adjacent interlocking elements 504 may be interleaved between each other to removably couple adjacent cell bodies 502. Under normal load, these interlocking elements 504 of adjacent unit bodies 502 do not become in contact with each other. Under accidental loading, greater than normal deformation brings the interlocking elements 504 into contact so that they contribute to the strength of the porous structure 500. The connecting element 506 connecting the unit bodies 502 also serves as an outer layer 506 (fig. 5C). The outer layer 506 is designed to provide flexibility within a desired range. In the example shown in fig. 5C, the desired flexibility is achieved by slit-shaped perforations in a staggered (stabgered) configuration. Other designs of the connecting element 506 are possible, such as a spring-like design, or the designs of fig. 1 and 4 with or without additional interlocking elements (e.g., interlocking elements 104, 204, 304, 404, etc.). Fig. 5D shows the assembly of the elements of fig. 5A-5C. The example of fig. 5A-5E has a circular cross-section and a cylindrical shape, but both the cross-section and the longitudinal shape may be adapted to the purpose of the medical device. This example is particularly suitable for the design of bone defect filler implants, in particular for bone defect filler implants for long and thin bones such as the radius, ulna, humerus, femur, tibia, fibula, rib, clavicle, mandible, phalanges, metacarpal and metatarsals.

Examples of similar structures 600 having different cross-sections are shown in fig. 6-8. For example, the structure 600 includes a cell body 602, an interlocking element 604, a layer 608, and a connecting element 606. The different elements of this example follow the same principles as the example of fig. 5A to 5E. However, this example has a polygonal cross-section, in particular a hexagonal cross-section. A cross-section having a more regular shape (such as triangular, rectangular, square, hexagonal, etc.) allows the repeating units of the porous structure to form a plate-like structure (such as plate-like structure 900, which can be seen in fig. 9) or to form a volume of the porous structure (such as volume 1000 of the porous structure, which can be seen in fig. 10). Such a plate-like structure may be shaped to cover the bone contacting surface of the implant. Alternatively, such a plate-like structure may be shaped to form the body of a plate-like implant such as a skull plate. The volume of the porous structure may be shaped or trimmed to form the body or a portion of the body of an implant, such as spinal spacer 1005 of fig. 10A, glenoid implant 1700 of fig. 17, or other implant (such as a bone defect filling implant).

The prior art implant 9 shown in fig. 22 is connected to the bone by end portions 10 and 11. These end portions, although also porous, require so much reinforcement around many set screw holes 12 that they may not achieve low stiffness at normal loads targeted for other portions of the implant 9. This can be problematic because the bone-implant interface, i.e., the osteotomy plane where the bone has been cut, is not loaded and all of the load is redirected to the side of the bone via the harder end and the harder set screw. In other words, less bone ingrowth is expected at the bone-implant interface.

Certain embodiments herein provide a fixation system having similar mechanical properties to the porous structure of WO/2017/042366 (such as shown in any of figures 1 a-7, 10 a-17 b, or 19 a-19 d, and described in the specification at page 9, line 31-page 15, line 18, page 17, line 14-page 23, line 16, or page 25, lines 4-28): the stiffness is lower under normal load and the strength is higher under higher (i.e. accidental) load. To achieve this behavior, in certain embodiments, the fixation system uses an internal structure according to WO/2017/042366 (such as shown in any of fig. 1 a-7, 10 a-17 b, or 19 a-19 d, and described at page 9, line 31-page 15, line 18, page 17, line 14-page 23, line 16, or page 25, lines 4-28 in the specification), an internal structure according to embodiments described herein, or a combination of both. In certain embodiments, the fixation system comprises one or more stems (stem), nails, screws, and/or bolts, and optionally one or more plugs (plugs).

The stem, nail, screw and/or bolt may have an internal structure according to the porous structure of WO/2017/042366 (such as shown in any of figures 1a to 7, 10a to 17b or 19a to 19d and described at page 9, line 31 to page 15, line 18, page 17, line 14 to page 23, line 16 or page 25, lines 4-28 in the description) or according to embodiments described herein.

In some embodiments, the shaft of the primary shaft, nail, screw, and/or bolt has an outer shell and an inner core. In some embodiments, the housing may have a spiral design according to fig. 1. In the case of a screw or bolt, the thread may follow a helix. An example of such a screw 1100 is shown in fig. 11-12. As shown, the housing includes a helical body 1102 having threads 1104 and an interlocking element 1106. Unfortunately, because the housing is helical, the housing provides little torsional resistance until the interlocking elements 1106 contact. However, in some embodiments, torsional stiffness may be increased by having an inner core as shown in fig. 12 that includes longitudinal sliding elements 1108, some of which are connected to the screw head 1110 and some to the screw tip 1112, which prevents torsion between the head 1110 and the tip 1112.

In certain embodiments, the shank of the nail, screw, and/or bolt has a housing with a structure according to the cross-spiral design of fig. 4 (e.g., two or more spirals are possible, such as screw 1300 with spirals 1302 and 1304 as shown in fig. 13). The thread may then follow a helix. In this embodiment, the presence of the intersecting helix provides torsional stiffness. The central core may remain open, may be filled with the sliding element 1108 of fig. 12, or may be filled in another manner (e.g., with a porous structure). In certain embodiments, the central core does not prevent compression and extension of the helical body under normal load. One example is a porous structure comprising a plurality of interconnected elements extending inwardly from a housing.

As illustrated in fig. 14A-14F, another embodiment may have a single helical body (e.g., helical body 1402 or 1404 as shown in fig. 14D or 14E) or a cross-helical body (e.g., helical bodies 1402 and 1404 as shown in fig. 14F) occupying the outer shell, and have interlocking elements 1406 occupying the inner core.

Another embodiment may have two parallel helices (e.g., helices 1502 and 1504), which are connected in a staggered configuration at a spacing 1506 as in screw 1500 shown in fig. 15. This design limits compression, rather than extension, under accidental loading.

A particular example of a screw according to one embodiment is a dental implant 2000 as can be seen in fig. 20. The stem of the dental implant may have any of the configurations of the previous embodiments. In dental implants, infections due to bacteria present in the oral cavity are considered to be the cause of bone loss. It may therefore be suitable to provide the implant with an antimicrobial coating and/or to provide a strong, smooth portion of the stem where the implant protrudes from the bone.

For some implants, the load between the implant and the bone is transmitted by shear stress, which is not natural to the bone. Bone is primarily capable of withstanding compressive loads. Localized shear stresses around the fixation screw may cause damage to the bone.

As discussed, in certain embodiments, such as shown in fig. 11-12, the screws include a flexible porous structure (e.g., the spiral design of fig. 1) that promotes bone ingrowth into the screw, which can aid in fixation. However, in certain situations (such as revision surgery), it may be desirable to remove/extract the screws from the bone after insertion into the bone. It may also be desirable to reduce the damage to the bone when removing the screw. Accordingly, certain embodiments herein provide one or more struts (strut) along a flexible porous structure configured with sharp edges. The sharp edge is positioned such that as the screw is rotated (e.g., counterclockwise) to remove the screw from the bone, the sharp edge cuts or severs the bone in-growth into the screw, thereby allowing the screw to be removed more cleanly and with less chance of additional injury to the bone. In certain aspects, the severed ingrowth bone may fall into the screw and thus be removed along with the screw.

Fig. 12A-12C illustrate an example screw including a flexible porous structure, and a strut configured to cut off ingrown bone. As shown, the screw includes a first helical structure 1202 surrounding the screw (e.g., on a cover of the screw), which includes threads. The screw further includes a second helical structure 1204, the second helical structure 1204 including a plurality of struts 1206. As shown, struts 1206 are formed along the length of the screw (e.g., corresponding to the longitudinal struts). The edges of the posts 1206 may be formed as sharp edges (e.g., as shown more clearly in fig. 12B and 12C), according to any number of suitable designs. Thus, as the screw is rotated and removed from the bone, the helical structures 1202 and 1204 slide through the bone in a cavity where the screw initially occupies and the post 1206 further collides with the bone already growing into the open hole of the porous structure of the screw. During this removal, the sharp edges of the strut 1206 cut the bone, allowing the strut 1206 to move through the bone.

In certain aspects, as shown in various embodiments in fig. 12, the cross-section of the strut may have an angle of 70 degrees, a lower angle, a higher angle, and the like. In certain aspects, some or all of the posts 1206 and/or additional posts for different screw designs (e.g., such as the designs in fig. 11-15) include such sharp edges.

In some embodiments, a fixation system is used to attach an implant to an anatomical portion (e.g., bone) of a patient. To overcome the above disadvantages, the fixation system may be designed according to the main loads expected at the implant/anatomical interface. Bone, for example, is molded (model) to itself bear the primary stress. In some embodiments, the implant may be designed to have an interface with the bone that is substantially perpendicular to the direction of these primary stresses in order to effectively transfer the load from the bone to the implant. In certain embodiments, the fixation system is also designed to maintain the transfer of loads at the interface and not transfer the loads to another location or convert the loads to other types of loads (e.g., from compression/tension to shear). Thus, nails, screws and/or bolts may be applied perpendicularly to the implant/anatomical interface.

One embodiment of an implant fixation system is a peg or rod attached to the implant, such as can be seen in fig. 16 for glenoid implant 1600. In one embodiment, the implant 1600 has a solid metal core 1610, perforations 1602 for screw insertion, a porous layer 1604 for bone ingrowth, and porous pins 1608 for stabilization and fixation. To avoid stress shielding and to promote bone ingrowth, one of the porous structures described herein or WO/2017/042366 (such as shown in any of fig. 1 a-7, 10 a-17 b, or 19 a-19 d, and described at page 9, line 31-page 15, line 18, page 17, line 14-page 23, line 16, or page 25, lines 4-28 in the specification) may be used for the nail 1608, the porous layer 1604 (described herein as a regular porous structure), and/or the set screw (not shown in the figures).

Another example embodiment of an implant fixation system is a combination of a glenoid implant 1700 such as can be seen in fig. 17 and one or more screws as can be seen in fig. 11-15. In one embodiment, glenoid implant 1700 has a porous structure 1704 that is a solid metal substrate 1710, in accordance with other aspects of the present invention, and that can accommodate large bone defects. The porous structure 1704 is oriented to accommodate the primary load at the glenoid. At side 1712, implant 1700 has smooth walls to avoid injury or irritation to muscles, tendons, nerves, and blood vessels as they move over the surface.

Another example embodiment is a femoral implant 1800 as can be seen in fig. 18. In one embodiment, the structure 506 of fig. 5 is applied to a portion of the main shaft of the implant 1800. In this way, the main shaft can be designed to be flexible enough to avoid stress shielding and promote bone ingrowth, while being strong enough to withstand accidental loading.

Another example embodiment is a knee implant 1900 as can be seen in fig. 19. In one embodiment, as shown, the knee implant 1900 includes a metal femoral component 1902, a metal tibial component 1904, and a polymer spacer (not shown). Each metal component has a solid metal core 1906/1908, one or more bone facing surfaces 1910/1912, and one or more spikes 1914/1916. The spikes 1914/1916 may be cylindrical, conical, finned, or any other suitable shape. To promote ingrowth, the bone facing surface 1910/1912 may be covered in a porous structure. The porous structure may be a regular structure (e.g. a repeating unit cell as known in the art), a structure according to WO/2017/042366 (such as shown in any of figures 1a to 7, 10a to 17b or 19a to 19d and described at page 9, line 31 to page 15, line 18, page 17, line 14 to page 23, line 16 or page 25, lines 4-28 in the description) or a structure according to embodiments discussed herein. The structure may be oriented to accommodate the prevailing load direction. To promote bone ingrowth and prevent stress shielding, the nail may be designed to include one of the following porous structures: such as the porous structures shown in any of figures 1a to 7, 10a to 17b or 19a to 19d of WO/2017/042366 and described at page 9, line 31 to page 15, line 18, page 17, line 14 to page 23, line 16 or page 25, lines 4-28 of the specification, or in the examples discussed herein.

One embodiment (such as shown in fig. 21D) provides a fixation system 2100 for an elongated bone, such as a mandible, a diaphysis of a femur, a tibia, a fibula, a humerus, a radius, an ulna, a rib, a clavicle, a metacarpal, a metatarsal, a phalanx. In particular, in bones with a small cross section, fixing an implant replacing the bone with the following fixation system can be a challenge: the fixation system has an interface perpendicular to the axis of the bone, and a set screw substantially parallel to the axis of the bone. According to this embodiment, the implant fixation system 2100 includes the following elements:

a main body 2102, as shown in fig. 21A. The main body 2102 replaces a portion of bone. In one embodiment, the main body 2102 has a porous structure according to WO/2017/042366 (such as shown in any of fig. 1 a-7, 10 a-17 b, or 19 a-19 d, and described at page 9, line 31-page 15, line 18, page 17, line 14-page 23, line 16, or page 25, lines 4-28 in the specification) or according to embodiments disclosed herein. The main body 2102 has an interface 2104 with the bone, the interface 2104 being substantially perpendicular to an axis of the bone. The main body 2102 includes a connection element 2103, the connection element 2103 connecting the interface 2104 to a bolt or screw receiving element 2105. The space between the interface 2104 and the receiving element 2105 forms a volume for a bolt or screw to be located inside.

A bolt or screw 2106, as shown in fig. 21B. To overcome the limited size challenges and still enable the bolt or screw 2106 to be aligned within the bone/implant interface and substantially parallel to the axis of the bone, the head 2110 of the bolt or screw 2106 may be located within the volume of the main body 2102. The interface 2104 and the receiving element 2105 limit movement in a direction perpendicular to the axis of the bone of the bolt or screw 2106. The main body 2102 may have an aperture 2108, the aperture 2108 further extending along the axis of the bolt or screw 2106 to allow insertion of a screwdriver. Alternatively, the head 2110 of the bolt or screw 2106 may be made accessible from that side, such that the bolt or screw 2106 may be secured with a wrench or with a pin that may grasp the head 2110 of a series of holes 2112 of the head 2110 of the bolt or screw 2106. In one embodiment, the bolt or screw 2106 has a porous structure as shown above for the stem, nail and screw.

A plug 2120, optionally as shown in fig. 21C. In particular, when there is no room to provide the screwdriver with the aperture 2108 and the bolt or screw 2106 needs to be tightened from the side, it is difficult for the surgeon to exert sufficient pressure on the bolt or screw 2106 to drive it into the bone. Accordingly, in one embodiment, the implant fixation system further comprises a plug 2120. The hole for the plug 2120 may be pre-drilled, such as using a (patient-specific) drill guide. The plug 2120 may then be inserted into the hole, for example manually or using a hammer. The plug 2120 includes an external feature 2122 to limit rotation (e.g., a fin parallel to the axis of the plug). The plug 2120 also includes at least one element to prevent withdrawal when the implant is secured to bone. This may be one or more of the following: as the bolt 2106 is driven into the plug 2120, the one or more elements are pushed outward. Alternatively, at least one element may be one or more anchor screws or nails (as known from intramedullary nails) inserted at a 90 degree angle to the axis of plug 2120. In one embodiment, the plug 2120 has a porous structure as shown above for the main rod, the nail and the screw.

One advantage of using bolt 2106 and plug 2120 is that plug 2120 can be designed to fit the shape of a bone. For example, the plug 2120 may be given a diameter that is best suited for the cross-section of bone. For example, the plug 2120 may be sized (dimensioned) to fit between the walls of the cortex of the bone.

An important advantage of using an implant fixation system in which (e.g., all) elements have a porous structure as described herein is that not only the design of the implant promotes bone ingrowth, but the fixation system also promotes bone ingrowth.

Certain embodiments provide a flexible porous structure for implantation into bone. In certain embodiments, the structure comprises a helical structure, such as shown in any of fig. 1, 4, 5C, 5D, 6-13, 14D-16, 19, or 20. Further, the structure includes a plurality of interlocking elements coupled to a helical structure, the helical structure configured to connect the plurality of interlocking elements, such as shown in any of fig. 1, 4, 5A, 5B, 5D-16, 19, or 20. Each interlocking element of the plurality of interlocking elements is configured to: when in the neutral position (neutral), there is a space between the interlocking element and the helical structure, and a space between the interlocking element and an adjacent interlocking element. The plurality of interlocking elements are configured to: when a compressive force is applied to the flexible porous structure, the helical structure is contacted, thereby limiting compression of the helical structure. The plurality of interlocking elements are configured to: when an extension force is applied to the flexible porous structure, adjacent interlocking elements are contacted, thereby limiting extension of the helical structure.

In certain embodiments, such as shown in fig. 1, 4, 11-13, or 15, the helical structure and the plurality of interlocking elements form a surface of a hollow cylinder. In certain embodiments, such as shown in fig. 1, 11, or 12, each of the plurality of interlocking elements comprises a T-shaped structure, and adjacent interlocking elements are oriented in mirror image of each other.

In certain embodiments, such as shown in fig. 5A-10 or 14F, the helical structure forms a surface of a cylinder and the plurality of interlocking elements are positioned inside the cylinder.

In certain embodiments, such as shown in fig. 11-15 or 20, the flexible porous structure comprises a screw, wherein the helical structure comprises a housing of the screw. In certain embodiments, such as shown in fig. 11-15 or 20, the screw includes threads formed on the housing. In certain embodiments, such as shown in fig. 11-12C, 15, or 20, the threads are aligned with the helical structure. In certain embodiments, such as shown in fig. 13, the threads form a cross-helical design with the helical structure.

In some embodiments, the screw comprises an inner core comprising a plurality of sliding elements, the plurality of sliding elements comprising: a first sliding element and a second sliding element, the first sliding element being coupled to the head of the screw and the second sliding element being coupled to the tip of the screw, wherein: the plurality of sliding elements are configured to: when in the neutral position, there is a space between the first and second slide elements, and the first slide element is configured to: when a force (e.g., a compressive force, a torsional force, etc.) is applied to the flexible porous structure, the second sliding element is contacted, thereby limiting compression and/or torsion of the helical structure, such as shown in fig. 12. In some such aspects, the first and second slide elements are configured to resist twisting of the screw about a longitudinal axis of the screw.

In some embodiments, the screw comprises an inner core comprising a plurality of sliding elements including a first sliding element coupled to the head of the screw and a second sliding element coupled to the tip of the screw, wherein: the first and second slide elements are configured to slide relative to each other along a longitudinal axis of the screw, such as shown in fig. 12. In some such aspects, the first and second slide elements are configured to resist twisting of the screw about the longitudinal axis.

In certain embodiments, a helical structure such as that shown in fig. 12A-12C includes at least one strut (e.g., formed along the length of the screw) that includes a sharp edge.

Certain embodiments provide an implant fixation system that includes a body comprising a porous structure, the body configured to engage a bone perpendicular to an axis of the bone, such as shown in fig. 21A. The implant fixation system also includes a screw including a head, such as that shown in fig. 21B. Such as shown in fig. 21D, the head is configured to be located within the volume of the body, while a portion of the screw extends away from the body. The body is configured to limit movement of the head within the body along an axis of the bone.

In some embodiments, the implant fixation system further comprises a plug configured to receive a portion of the screw, wherein the plug is configured to be inserted into a hole formed in the bone, such as shown in fig. 21C. In some embodiments, such as shown in fig. 21C, the plug includes an external feature configured to limit rotation of the plug in the bore. In certain embodiments, such as shown in fig. 21D, the head includes a second porous structure.

In certain aspects, embodiments described herein, such as implants, porous structures, flexible porous implant fixation systems, and the like, may be fabricated using an additive manufacturing AM process.

The AM process is a material addition atlas used to build parts, usually starting from a base material in liquid, solid sheet or powder form, and locally consolidating the added material in a layer-by-layer manner. Since the first AM process emerged in the early 1990 s, the AM process has been used as an alternative to traditional material removal techniques, such as milling, cutting or drilling or molding techniques (such as injection molding or extrusion), and has been shown to be particularly effective in: complex parts are produced in a relatively short time without the need for special tools such as molds (mold) or dies (die).

The most well-known AM techniques include Stereolithography (SLA), 3D printing (3D-P), Selective Laser Sintering (SLS), Selective Heat Sintering (SHS), Selective Laser Melting (SLM), Direct Metal Laser Sintering (DMLS), Laser Beam Melting (LBM), and Electron Beam Melting (EBM). These techniques vary depending on the tool used to secure the various layers of the component, and depending on the materials that may be used in the technique.

The systems and methods described herein may be performed using various additive manufacturing and/or three-dimensional (3D) printing systems and techniques. Typically, additive manufacturing techniques begin with a digital representation of the 3D object to be formed (e.g., a CAD file (such as STL, DWG, DXF, etc.), a mesh-based model, a voxel-based model, etc.). Typically, the digital representation is divided into a series of cross-sectional layers (e.g., perpendicular to the Z-direction, meaning parallel to the build platform) or "slices" that are overlapped to form the object as a whole. The layers represent 3D objects and may be generated using additive manufacturing modeling software executed by a computing device. For example, the software may include computer aided design and manufacturing (CAD/CAM) software. Information about the cross-sectional layer of the 3D object may be stored as cross-sectional data. An additive manufacturing (e.g., 3D printing) machine or system utilizes the cross-sectional data for purposes of building a 3D object layer-by-layer. Thus, additive manufacturing allows 3D objects to be prepared directly from computer generated data of the object, such as a Computer Aided Design (CAD) file or STL file. Additive manufacturing provides the ability to quickly manufacture simple and complex parts without the use of tools and without the need for assembly of different parts.

The additive manufacturing process typically comprises: energy is provided from an energy source (e.g., laser, electron beam, etc.) to cure (e.g., polymerize) a layer of build material (e.g., plastic, metal, etc.). For example, an additive manufacturing machine may selectively apply (e.g., scan) energy from an energy source to a build material based on a job file. The job file may include information about: a slice of a digital representation of one or more objects to be built using an additive manufacturing process. For example, a 3D object represented by a CAD file may be arranged in a virtual build volume corresponding to a build volume of an additive manufacturing device. Optionally, support structures may be added to the 3D object in the virtual build volume (e.g., to improve build quality, dissipate heat, reduce distortion, etc.). As discussed, the resulting 3D object may be divided into layers or slices. Thus, the job file may include slices (e.g., stacks of slices) of the 3D object, as well as parameters of the additive manufacturing machine used to build the 3D object.

For example, for each slice, the job file may include information about a scan pattern for causing an energy source to apply energy (e.g., apply a laser scan, apply an electron beam scan, etc.) to a physical layer of build material corresponding to the slice. It should be noted that the terms slice and layer may be used interchangeably as discussed herein. The scan pattern may include one or more vectors, each vector indicating a spatial location to apply energy to a layer of build material and a direction to apply energy to the build material (e.g., a direction to move a laser beam, electron beam, or other energy source over the build material while scanning).

An additive manufacturing machine builds an object layer by applying energy (e.g., scanning) to layers of build material according to a scan pattern for each individual layer as indicated in a job file. For example, an additive manufacturing machine may scan a first layer of physical build material corresponding to a first slice of a digital representation of an object according to a scan pattern for the first slice. The additive manufacturing machine may then scan a second layer of build material corresponding to a second slice adjacent to the first slice according to the scan pattern for the second slice. The additive manufacturing machine continues to scan the layers of build material corresponding to all slices in the job file until the layer corresponding to the last slice is scanned.

Embodiments of the invention may be practiced within a system for designing and manufacturing 3D objects. Turning to FIG. 23, an example of a computer environment suitable for implementing 3D object design and fabrication is shown. The environment includes a system 2300. The system 2300 includes one or more computers 2302a-2302d, which may be, for example, any workstation, server, or other computing device capable of processing information. In some aspects, each of the computers 2302a-2302d may be connected to the network 2305 (e.g., the internet) by any suitable communication technology (e.g., internet protocol). Accordingly, the computers 2302a-2302D may transmit and receive information (e.g., digital representations of software for 3-D objects, commands or instructions to operate an additive manufacturing device, etc.) between each other via the network 2305.

The system 2300 also includes one or more additive manufacturing devices (e.g., 3-D printers) 23025a-23025 b. As shown, additive manufacturing device 23025a is connected directly to computer 2302d (and through computer 2302d, to computers 2302a-2302c via network 2305), and additive manufacturing device 23025b is connected to computers 2302a-2302d via network 2305. Thus, those skilled in the art will appreciate that the additive manufacturing apparatus 23025 can be directly connected to the computer 2302, connected to the computer 2302 via the network 2305, and/or connected to the computer 2302 via another computer 2302 and the network 2305.

It should be noted that although the system 2300 is described with respect to a network and one or more computers, the techniques described herein are also applicable to a single computer 2302, which may be directly connected to the additive manufacturing apparatus 23025. Any of the computers 2302a-2302d may be configured to function as the computing devices described with respect to fig. 1-21. Further, any of the computers 2302a-2302d may be configured to perform the operations described herein.

FIG. 24 illustrates a functional block diagram of one example of the computer of FIG. 23. The computer 2302a includes a processor 2410 in data communication with a memory 2420, an input device 2430, and an output device 2440. In some embodiments, the processor is also in data communication with an optional network interface card 2490. Although described separately, it is to be understood that the functional blocks described with respect to the computer 2302a need not be separate structural elements. For example, the processor 2410 and the memory 2420 can be implemented in a single chip.

The processor 2410 can be a general purpose processor, a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any suitable combination thereof designed to perform the functions described herein. A processor may also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration.

The processor 2410 can be coupled via one or more buses to read information from, and write information to, the memory 2420. The processor may additionally or alternatively contain memory, such as processor registers. The memory 2420 may include a processor cache including a multi-level hierarchical cache, where different levels have different capacities and access speeds. Memory 2420 may also include Random Access Memory (RAM), other volatile or nonvolatile storage. Storage devices may include hard disk drives, optical disks such as Compact Disks (CDs) or Digital Video Disks (DVDs), flash memory, floppy disks, tapes, and Zip drives.

The processor 2410 can also be coupled to an input device 2430 and an output device 2440 for receiving input from and providing output to, respectively, a user of the computer 2302 a. Suitable input devices include, but are not limited to: a keyboard, buttons, keys, switches, pointing device, mouse, joystick, remote control, infrared detector, bar code reader, scanner, camera (possibly coupled with video processing software to detect gestures or facial gestures, for example), movement detector, or microphone (possibly coupled to audio processing software to detect voice commands, for example). Suitable output devices include, but are not limited to, visual output devices (including displays and printers), audio output devices (including speakers, headphones, earphones, and alarms), additive manufacturing devices, and tactile output devices.

Processor 2410 can also be coupled to a network interface card 2490. Network interface card 2490 prepares data generated by processor 2410 for transmission over a network according to one or more data transmission protocols. Network interface card 2490 also decodes data received via the network according to one or more data transmission protocols. Network interface card 2490 may include a transmitter, a receiver, or both. In other embodiments, the transmitter and receiver may be two separate components. The network interface card 2490 may be implemented as a general purpose processor, a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any suitable combination thereof designed to perform the functions described herein.

FIG. 25 illustrates a process 2500 for manufacturing a 3-D object or device. As shown, at step 2505, a digital representation of the object is designed using a computer, such as computer 2302 a. For example, 2-D or 3-D data may be input to computer 2302a for use in assisting in designing a digital representation of a 3-D object. Continuing at step 2510, information is sent from computer 2302a to an additive manufacturing device, such as additive manufacturing device 23025, and device 23025 begins the manufacturing process according to the received information. At step 2515, additive manufacturing device 25025 continues to manufacture the 3-D object using a suitable material, such as a liquid resin. At step 2520, the object is finally constructed.

Such suitable materials may include, but are not limited to: photopolymer resins, polyurethanes, methylmethacrylate-acrylonitrile-butadiene-styrene copolymers, resorbable materials (such as polymer-ceramic composites), metals, metal alloys, and the like. Examples of commercially available materials are: from DSMSomos

Series of materials 7100, 8100, 9100, 9420, 10100, 11100, 12110, 14120, and 15100; ABSplus-P430, ABSi, ABS-ESD7, ABS-M30, ABS from Stratasys-M30i, PC-ABS, PC ISO, PC, ULTEM 9085, PPSF and PPSU materials; accura Plastic, DuraForm, CastForm, Laserform and Visijet materials series from 3D-Systems; PA material series, PrimeCast and PrimePart materials and Alumide and CarbonMide from EOS GmbH; aluminum, cobalt chromium alloys and stainless steel materials, maraging (Maranging) steel, nickel alloys, titanium and titanium alloys. The family of Visijet materials from 3-Systems may include Visijet Flex, Visijet Tough, Visijet Clear, Visijet HiTemp, Visijet e-Stone, Visijet Black, Visijet Jewel, Visijet FTI, and the like. Examples of other materials may include Objet materials such as Objet fulrcure, Objet Veroclear, Objet digital materials, Objet durushite, Objet Tangoblack, Objet tangopolus, Objet tangoblacklac, and the like. Another example of material may include material from Renshape 5000 and 7800 sequences. Additionally, at step 2520, a 3-D object is generated.

Various embodiments disclosed herein provide for the use of computer software executing on a computing device. Those skilled in the art will readily appreciate that the embodiments may be implemented with many different types of computing devices, including both general purpose and/or special purpose computing system environments or configurations. Examples of well known computing systems, environments, and/or configurations that may be suitable for use with the embodiments set forth above may include, but are not limited to, personal computers, server computers, hand-held or laptop devices, multiprocessor systems, microprocessor-based systems, programmable consumer electronics, network PCs, minicomputers, mainframe computers, distributed computing environments that include any of the above systems or devices, and the like. These devices may include stored instructions that, when executed by a microprocessor in a computing device, cause the computing device to perform specified actions to implement the instructions. As used herein, instructions refer to computer-implemented steps for processing information in a system. The instructions may be implemented in software, firmware, or hardware, and may include any type of programming steps undertaken by the components of the system.

The microprocessor may be any conventional general purpose single or multi-chip microprocessor, such as

A processor,

A processor, an 8051 processor,A processor,

Processor or

A processor. In addition, the microprocessor may be any conventional special purpose microprocessor, such as a digital signal processor or a graphics processor. Microprocessors typically have conventional address lines, conventional data lines, and one or more conventional control lines.

The aspects and embodiments of the invention disclosed herein may be implemented as a method, an apparatus, or an article of manufacture using standard programming or engineering techniques to produce software, firmware, hardware, or any combination thereof. The term "article of manufacture" as used herein refers to code or logic implemented in hardware or a non-volatile computer readable medium, such as an optical storage device, and in a volatile or non-volatile memory device or a transitory computer readable medium, such as a signal, carrier wave. Such hardware may include, but is not limited to, Field Programmable Gate Arrays (FPGAs), Application Specific Integrated Circuits (ASICs), Complex Programmable Logic Devices (CPLDs), Programmable Logic Arrays (PLAs), microprocessors, or other similar processing devices.

The various embodiments disclosed herein may be implemented using a computer or computer control system. Those skilled in the art will readily appreciate that the embodiments may be implemented with many different types of computing devices, including both general purpose and special purpose computing system environments or configurations. Examples of well known computing systems, environments, and/or configurations that may be suitable for use with the embodiments set forth above may include, but are not limited to, personal computers, server computers, hand-held or laptop devices, multiprocessor systems, microprocessor-based systems, programmable consumer electronics, network PCs, minicomputers, mainframe computers, distributed computing environments that include any of the above systems or devices, and the like. These devices may include stored instructions that, when executed by a microprocessor in a computing device, cause the computing device to perform specified actions to implement the instructions. As used herein, instructions refer to computer-implemented steps for processing information in a system. The instructions may be implemented in software, firmware, or hardware, and may include any type of programming steps undertaken by the components of the system.

The microprocessor may be any conventional general purpose single or multi-chip microprocessor, such asA processor,

A processor, an 8051 processor,A processor,Processor orA processor. In addition, the microprocessor may be any conventional special purpose microprocessor, such as a digital signal processor or a graphics processor. Microprocessors typically have conventional address lines, conventional data lines, and one or more conventional control lines.

Aspects and embodiments of the invention disclosed herein may be implemented as a method, apparatus or article of manufacture using standard programming or engineering techniques to produce software, firmware, hardware, or any combination thereof. The term "article of manufacture" as used herein refers to code or logic implemented in hardware or a non-volatile computer readable medium, such as an optical storage device, and in a volatile or non-volatile memory device or a transitory computer readable medium, such as a signal, carrier wave. Such hardware may include, but is not limited to, Field Programmable Gate Arrays (FPGAs), Application Specific Integrated Circuits (ASICs), Complex Programmable Logic Devices (CPLDs), Programmable Logic Arrays (PLAs), microprocessors, or other similar processing devices.