Patent Application
20220072205
The present invention generally relates to an orthopedic implant. Specifically, the present invention relates to an implant that incorporates a purposefully designed material that optimizes bony ingrowth combined with a support material configured to provide structural integrity.
Orthopedic implants are commonly used in a variety of orthopedic applications. While the structure of an implant is primarily based on application, a primary consideration for any implant is achieving a design the maximizes strength, while also promoting bone growth to achieve proper fusion between the implant and adjacent bone(s). Accordingly, implant designs have incorporated both nonporous and porous structures, with the goal of having the nonporous areas providing strength and structural support to the implant and the porous areas promoting bone growth and fusion.
Traditionally, a single material is used to form an orthopedic implant which includes a porous section and a solid section. For example, titanium metal has been used to form implants to provide both a porous section for bony ingrowth and a solid section for structural strength. However, titanium implants and implants formed from similar metal materials have a number of drawbacks including, that they have a high modulus of elasticity which inhibits bone growth, and that they are typically highly radio-opaque, preventing post-operative examination of bone growth with imaging technology.
Therefore, there is a need in the art for an implant and related manufacturing method that can, within a single implant, incorporate both solid nonporous and porous sections to provide both adequate structural support and promote optimal bone growth and fusion. The present invention is provided to solve the problems discussed above and other problems, and to provide advantages and features not provided by currently available implants. These and other features and advantages of the present invention will be explained and will become obvious to one skilled in the art through the summary of the invention that follows.
Accordingly, embodiments of the present invention are directed to an orthopedic implant with a first implant material optimized for bony ingrowth combined with a second implant material that provides structural support.
Embodiments of the present invention contemplate a first implant material comprising a bony ingrowth material engineered as a tubular network that forms one or more three-dimensional (“3D”) matrixes, which provide a porous region at any desired location within an implant and with any desirable pore structure, size, or porosity. The contemplated 3D matrix or matrixes may be formed of an osteo-conductive material or coated or infused with an osteo-conductive substance. The second implant material comprising a radio-lucent support material may be formed with or added to the first implant material to provide structural support to the implant while permitting radio-lucency.
The foregoing summary of the present invention with the preferred embodiments should not be construed to limit the scope of the invention. It should be understood and obvious to one skilled in the art that the embodiments of the invention thus described may be further modified without departing from the spirit and scope of the invention. Other features and advantages of the invention will be apparent from the following specification taken in conjunction with the following drawings. While many materials and methods of design have been attempted, a number of drawback and limitations prevent an optimal design.
Accompanying this written specification is a collection of drawings of exemplary embodiments of the present invention. One of ordinary skill in the art would appreciate that these are merely exemplary embodiments, and additional and alternative embodiments may exist and still be within the spirit of the invention as described herein.
The present invention generally relates to an orthopedic implant. Specifically, the present invention relates to an implant that incorporates a purposefully designed material that optimizes bony ingrowth combined with a support material configured to provide structural integrity.
According to an embodiment of the present invention, an orthopedic implant may comprise a first implant material comprising a bony ingrowth section engineered as a 3D matrix configured with a network of interconnected hollow tubes formed of ⊖-tricalcium phosphate (“β-TCP”), hydroxyl apatite (“HA”), or other natural bone ingrowth materials or a combination thereof, that provide a porous region within the implant for bony ingrowth, and a second implant material comprising a support material formed of polyether ether ketone (“PEEK”) or polyether ether ketone-hydroxyl apatite (“PEEK-HA”) that is formed with, added to, combined with, or otherwise coupled to the first implant material to provide structural support for the implant.
According to an embodiment of the present invention, an orthopedic implant includes a first implant material and a second implant material combined to form a substantially stable and structurally sound implant which in configured to promote bony ingrowth. In an exemplary embodiment, β-TCP, HA, or other natural bone growth material, or a combination of any of the foregoing may be used to form the first implant material which may include one or more hollow 3D matrixes having a network of continuously interconnected tubes to provide a porous region in the implant into which bone can grow. The first implant material may be combined or added to a second implant material that provides structural support to the implant such as PEEK, PEEK-HA, or titanium. In some embodiments, the first implant material and/or the 3D matrixes disposed therein may be made from or coated with hydroxyl apatite (“HA”) due to its osteo-conductive properties. However, any variety of osteo-conductive materials could be used for the first implant material, including, but not limited to, various bioactive glasses. The material used to provide structural support to the implant is preferably PEEK, but could formed of other biocompatible or radiolucent materials, or a combination of PEEK and any such biocompatible or radiolucent materials. The use of PEEK for structural support section of the implant is advantageous because PEEK has an elastic modulus that is similar to bone and is radiolucent, making it easier to observe bone growth and fusion within and around the implant. Other materials may be incorporated into the support structure material, including, but not limited to, HA, bioactive glasses, and any combination thereof, to further enhance the stimulation of bony ingrowth while permitting radio-lucency. One of ordinary skill in the art would appreciate that there are many other materials or combination of materials from which an orthopedic implant could be fabricated, and embodiments of the present invention are contemplated for use with any such material or combinations of materials.
According to an embodiment of the present invention, the 3D matrixes may be 3D printed, thereby allowing the creation of a precise structure. In some examples, 3D printing is capable of repeatedly creating 3D matrixes with identical specifications, including, but not limited to 3D matrixes with the same dimensions, pore structure, porosity, and pore size, with the only limitation on the implant design and size being the size of the machinery producing it. Additionally, each of these methods is capable of creating the porous structure within any section of the implant and at any depth. One of ordinary skill in the art would appreciate there are a variety of methods for implementing the 3D printing technique, and embodiments of the present invention are contemplated for use with any such methods.
According to an embodiment of the present invention, a 3D matrix may be a network of continuously connected tubes. Each of the hollow tubes may have a diameter between 0.5 mm and 1.0 mm. In some embodiments, however, the tubes may be smaller than 0.5 mm or larger than 1.0 mm. In an exemplary embodiment, each tube of the 3D matrix may intersect with another tube of the 3D matrix every 3.0 mm to 4.0 mm. Each tube may proceed uninterrupted for a length of approximately 3.0 mm to 4.0 mm before intersecting with another tube, however the interval may be longer or shorter depending upon the intended application of the implant. In some scenarios, the tubes of the 3D matrix are not in straight lines, but have curves, twists, angles, and other changes of direction, as this has been shown to improve bone growth and fusion. However, the 3D matrix could be configured with straight line tube structures if beneficial for a particular application. Additionally, the internal surface of the tubes of the 3D matrix may be roughened, to improve the growth and fusion of the bone tissue. One of ordinary skill in the art would appreciate that 3D matrix could be precisely designed with a tubular structure based upon the intended application or purpose of the implant, and embodiments of the present invention are contemplated for use with any such design.
According to an embodiment of the present invention, the first implant material may include a 3D matrix having a varying tubular structure thereby creating a variable porosity, or amount of hollow space, within the implant. Generally, the overall porosity of a given implant will be determined by the amount of hollow space in the first or second implant material. In some scenarios, the porosity of the first or second implant material may be specifically tailored based upon the application and purpose of the implant. Furthermore, the first or second implant materials or both may have multiple individual hollow 3D matrixes positioned in different portions of the respective implant materials. In this way, a given implant need not have a consistent porosity throughout, but instead could have a varying porosity in different sections of the implant to promote bone growth, or otherwise as necessary for a particular application of the implant. The customizable nature of the first and second implant materials, along with the variable design and placement of a 3D matrix within an implant, allows for an implant to configured in accordance with the intended application for the implant. Notably, the overall porosity of two different implants could be the same despite having vastly different design objectives. In some examples, the porosity of the implant may be approximately 50%, but may vary within an ideal range of between 20 to 80%.
In some embodiments, the support section 108 of the implant 100 includes one or more inserter apertures 115. In some embodiments, the inserter apertures 115 are configured to engage with an inserter (not shown). In some embodiments, an inserter (not shown) is used to connect to and hold the implant 100 while the implant 100 is inserted into a patient body during a given procedure.
In accordance with embodiments of the present invention, a porous implant section 106 including one or more 3D hollow matrixes 120 may be substantially comprised of a first implant material 102 for the promotion of bony ingrowth while an implant support section 108 may be substantially comprised of a radiolucent second implant material 104 configured to provide structural integrity and support to permit post-operative examination of bone growth with imaging technology. In some instances, the combination of a porous first implant material 102 and a substantially sturdy and generally nonporous second implant material 104 provides an implant having a solid, weight-bearing support section 108 adjacent to a substantially porous section 106 that supports bone growth and fusion which may allow for optimal imaging radio-lucency, a higher modulus of elasticity for the porous section 106 to promote the bone ingrowth capabilities of the implant 100. One of ordinary skill in the art would appreciate the implant of the present invention could be configured with any suitable porosity percentage, and embodiments of the present invention are contemplated for use with any such porosity percentage.
According to embodiments of the present invention, the implant 100 may be configured with a first implant material 102 adapted for optimal bony ingrowth combined with a second implant material 104 adapted to provide structural support to the otherwise weaker or more fragile first implant material. For example, the first implant material 102 may be HA or natural bone configured to promote bone ingrowth, and the second implant material 104 may be PEEK, PEEK-HA, or titanium, configured to provide structural support to the first implant material which typically lacks strength, for instance, during implantation of the implant 100. Moreover, once the implant is implanted into a body, the first implant material alone generally would not be able to withstand some of the natural forces expected to act on the implant, such as, for example, flexion and torsion.
In accordance with embodiments of the present invention, the size, weight, and porosity ratio of the first implant material 102 to the second implant material 104, as well as the arrangement of the first implant material 102 and the second implant material 104, are determined by the intended application for the implant 100. For example, an implant for use in the spine may have a different design than one intended for use in the hip. Additionally, the second implant material 104 of the implant 100 may be designed and arranged to provide structure and load bearing support, while the first implant material 102, formed in some instances with a substantially hollow 3D matrix 120, may provide bone growth and fusion functionalities. One of ordinary skill in the art would appreciate that there are many suitable designs and arrangements for the first and second implant materials of the proposed implant, and embodiments of the present invention are contemplated for use with any such design or arrangement.
As shown in
According to an embodiment of the present invention, the implant 100 may be configured with one or more cavities 122 in one or more walls of the first or second implant materials 102 and 104. In some embodiments, a cavity 122 may be a channel that goes entirely through a wall of the implant 100. A cavity 122 may be added to the implant 100 to adapt the implant 100 to a certain application or to improve the performance of the implant 100. One of ordinary skill in the art would appreciate that there are many suitable designs and layouts for incorporating cavities into the walls of the implant, and embodiments of the present invention are contemplated for use with any such cavity design and layout.
As shown in
According to an embodiment of the present invention, the implant may be designed with a precise hollow tubular structure based on the implant's intended application. In some embodiments, the 3D matrix of the implant may be designed using computer-aided design (“CAD”) techniques. In some embodiments, the tubular structure may be configured in a CAD model that can then be used to control 3D printing manufacturing process. Furthermore, the 3D matrix created by 3D printing methods can be tailored to create specific tube sizes and structures. Finally, the use of CAD models in conjunction with 3D printing, allows for the precise reproduction of identical implants. This was not possible with previous methods, such as the gas-evaporative method, which could not replicate implants with identical structures.
While multiple embodiments are disclosed, still other embodiments of the present invention will become apparent to those skilled in the art from this detailed description. There may be aspects of this invention that may be practiced without the implementation of some features as they are described. It should be understood that some details have not been described in detail in order to not unnecessarily obscure focus of the invention. The invention is capable of myriad modifications in various obvious aspects, all without departing from the spirit and scope of the present invention. It should be noted that the features illustrated in the drawings are not necessarily drawn to scale, and features of one embodiment may be employed with other embodiments as the skilled artisan would recognize, even if not explicitly stated herein. Accordingly, the drawings and descriptions are to be regarded as illustrative in nature and not restrictive.
