US20190142597A1 - Attachments for orthopedic implants - Google Patents

Abstract

Apparatuses, kits, and methods for cementing an orthopedic implant to a bone, post attachment, are disclosed in some aspects of the present disclosure. A kit can include a prosthetic component and a cement applicator. The prosthetic component can include an attachment profile that corresponds to a mating profile formed on or in a bone. The cement applicator can be configured to apply a bone cement between the bone and the prosthetic component following alignment between the prosthetic component and the bone or another prosthetic component. The kit can also include a bone cement. A method can include positioning the prosthetic component adjacent to the bone, aligning the prosthetic component relative to the bone or another prosthetic component, and applying a bone cement between the bone and the aligned prosthetic component.

Description

CLAIM OF PRIORITY
• This patent application is a divisional Ser. No. 15/041,706, filed on Feb. 11, 2016, which is a continuation of U.S. patent application Ser. No. 13/774,629, filed on Feb. 22, 2013, now issued as U.S. Pat. No. 9,295,554, which is a continuation-in-part of U.S. patent application Ser. No. 13/545,119, filed on Jul. 10, 2012, each of which are hereby incorporated by reference herein in its entirety, and the benefit of priority of each of which are hereby claimed.
BACKGROUND
• Prosthetic components are available, for example, to replace bodily components or portions of bodily components that cannot be regenerated or are no longer functioning properly. Examples of prosthetic components include heart valves, pacemakers, collagen for soft tissue augmentation, and orthopedic components, such as fracture plates and artificial knee, hip, and ankle joints.
SUMMARY
• One aspect of the present disclosure provides a method for attaching a prosthetic component to a bone. This particular method includes a step in which a prosthetic component with an attachment profile is provided. In another step, a mating profile is formed in a bone of a patient. Thereafter, the prosthetic component is positioned adjacent the bone with the attachment profile associating with the mating profile in a male-female mating relationship that leaves at least one open space between the prosthetic component and the bone. In another step, a biocompatible adhesive material is delivered into the at least one open space.
• In another aspect, the present disclosure provides a prosthesis that is positionable between a first bone surface and a second bone surface in a patient. The prosthesis includes a first prosthetic component and stackable, second prosthetic component that is stackable onto the first prosthetic component. The first prosthetic component includes a first attachment profile that is associable with a mating profile of the first bone surface in a male-female mating relationship and a second attachment profile that is associable with a mating profile of the second bone surface in a male-female mating relationship. The second prosthetic component includes an attachment profile that replicates the first attachment profile of the first prosthetic component to allow association with the mating profile of the first bone surface in a male-female mating relationship and a mating profile that replicates the mating profile of the first bone surface to allow association with the first attachment profile of the first prosthetic component in a male-female mating relationship.
• The present disclosure, in certain other aspects, is directed to apparatus, kits, and methods for the implantation and stabilization of an orthopedic implant to a bone using a filler material such as bone cement. The apparatus, kits, and methods of certain embodiments of the present disclosure can include the use of a cement applicator, such as a syringe, to deliver the bone cement or a cement precursor to one or more desired locations between a prosthetic component of an orthopedic implant and a bone to which the prosthetic component is attached. Use of the cement applicator in such instances allows a surgeon or other medical practitioner to insert, position, align, and attach the prosthetic component prior to the application of bone cement, allowing for appropriate component positioning or alignment and cleaner application of the bone cement, e.g., a bioabsorbable bone cement.
• A kit can include a prosthetic component including an attachment profile corresponding to a mating profile formed on or in a bone, and a cement applicator configured to apply a bone cement between the bone and the prosthetic component, following alignment between the prosthetic component and the bone or a second prosthetic component.
• A method of implantation can include positioning a prosthetic component adjacent to a bone, aligning the prosthetic component with respect to the bone or with respect to another prosthetic component, or both, and applying a bone cement between the bone and the aligned prosthetic component.
• A kit can include a disclosed prosthetic device for positioning adjacent to a bone, aligning with respect to the bone or with respect to another prosthetic device, or both, and attaching to the bone, and cement for applying between the bone and the aligned and attached prosthetic device.
BRIEF DESCRIPTION OF THE DRAWINGS
• In the drawings, like numerals can be used to describe similar elements throughout the several views. Like numerals having different letter suffixes can be used to represent different views or instances of similar elements. The drawings illustrate generally, by way of example, but not by way of limitation, various embodiments discussed in the present document.
• FIG. 1 is a schematic view of an example orthopedic ankle implant positioned in a patient.
• FIG. 2 is a close-up schematic view of an example orthopedic ankle implant having bone cement applied between a bone and a prosthetic component of the orthopedic ankle implant.
• FIG. 3 is an isometric view of an example orthopedic ankle implant.
• FIG. 4 is a schematic view of an example orthopedic ankle implant having bone cement being applied between a bone and a prosthetic component of the orthopedic ankle implant using a cement applicator.
• FIG. 5 is a flow chart of an example method of implanting an example prosthetic component.
• FIG. 6 is a flow chart of an example method of implanting an orthopedic ankle implant including two or more prosthetic components.
• FIG. 7 is a close-up schematic view of another example orthopedic ankle implant.
• FIG. 8 is a close-up schematic view of an example ankle fusion device.
DETAILED DESCRIPTION
• The present disclosure, in certain aspects, includes apparatuses, kits, and methods for the implantation and affixing of a prosthetic component of an orthopedic implant to a bone using bone cement. These particular apparatuses, kits, and methods can include the use of a cement applicator, such as a syringe, to deliver a bone cement or a cement precursor to one or more desired locations between a prosthetic component of an orthopedic implant and a bone to which the prosthetic component is attached. Use of the cement applicator can allow a surgeon or other medical practitioner to insert, position, and align the prosthetic component to a bone prior to the application of bone cement. In contrast, existing implantation methods include the application of bone cement, if at all, either to the prosthetic component or to the bone prior to inserting the prosthetic component into the patient, often leading to bone cement being inadvertently spread to unintended or undesirable locations or hardening (e.g., setting) prior to proper component positioning and alignment, all while operating under the timing duress imparted by a limited working time of the cement.
• The present apparatus, kits, and methods can provide for the use of less cement and can provide for less cement clean-up compared to existing methods of bone cement application. Additionally, the present apparatus, kits and methods can allow for alignment of the prosthetic component prior to application of the bone cement, thereby allowing for more precise placement and alignment of the prosthetic component. Moreover, because bone cement can be precisely applied using the present cement applicator, the bone cement can be applied to locations that will increase the chances of fixation of the prosthetic component to the bone.
• In various examples, the present apparatus, kits, and methods can be used with orthopedic implant systems (e.g., ankle joints, wrist joints, elbow joints, knee joints, hip joints, shoulder joints, finger joints, toe joints, and in a variety of fusion and fusion-type devices including ones utilized in and around the above joints and elsewhere in the skeletal system including in the spine) where bone cement is desirable for fixation and stabilization of a prosthetic component to a bone, particularly when precise application of bone cement is difficult due to space constraints. An example of an orthopedic implant system in which the present apparatus, kits, and methods can be used is an orthopedic ankle implant, such as an implant that may be used for total ankle arthroplasty (“TAA”) surgery, also known as total ankle replacement. An ankle implant used for TAA surgery is often inserted through an anterior or lateral ankle arthrotomy. A small portion of bone, such as a small portion of a tibia and/or a talus, can be removed to make room for one or more components of the ankle implant. The portion of bone that is removed from the tibia and/or talus is often only a centimeter or less in thickness, and the implant components to be inserted can be only slightly smaller, if at all, than the vacated space.
• FIG. 1 is a schematic view of an exampleorthopedic ankle implant10 positioned within apatient1. Bones located within the leg, foot, and ankle of thepatient1 include thetibia2, the talus4, and the fibula6. Theankle implant10 can comprise atibial component12 and atalar component14. Thetibial component12 can be affixed to a distal portion of thetibia2 and thetalar component14 can be affixed to a proximal portion of the talus4. Theankle implant10 can further comprise a bearing component, such as apolymeric bearing component16, positioned between thetibial component12 and thetalar component14 and providing an articulating surface. An example of a material that can be used to form thebearing component16 is ultra-high molecular weight polyethylene (UHMPWPE). For example, thebearing component16 can be coupled to thetibial component12 on a first surface and can articulate against thetalar component14 on a second surface.
• An exemplary ankle implant for use with the present apparatuses, kits and methods is shown and described in U.S. Pat. Nos. 7,625,409; 7,963,996; 7,025,790; and 7,238,190, all of which are hereby incorporated by reference in their entirety.
• Each of thetibial component12 and thetalar component14 can comprise an attachment profile or feature(s) corresponding to a mating profile or feature(s) formed in thetibia2 and the talus4, respectively. InFIG. 1, for example, the attachment profile of thetibial component12 is substantially analogous to the mating profile of thetibia2 allowing thetibial component12 to fit with thetibia2 in a keyed arrangement. Similarly, the attachment profile of thetalar component14 can be substantially analogous to the mating profile of the talus4 allowing thetalar component14 to fit with the talus4 in a keyed arrangement. The mating profiles of thetibia2 and the talus4 can also each include one or more cavities, void spaces, or other female-type mating features in addition to its other mating surfaces. A bone cement can be precisely applied in and/or on the cavities, void spaces, or other features of the mating profile after thecomponents12,14 have been inserted into thepatient1 or attached to thetibia2 or talus4, respectively, for added stability.
• FIG. 2 is a close-up schematic view of the example implant10 ofFIG. 1. Prior to insertion of theankle implant10, a space can be formed between thetibia2 and the talus4 through the manipulation of a tibial distal surface3 or a talarproximal surface5, or both. The space can be formed by removing a portion of thetibia2 to form the distal surface3 and expose a proximal end of the talus4, or it can be formed by removing a portion of the talus4 to form theproximal surface5 and to expose a distal end of thetibia2, or both. Thetibial component12 can he inserted into the vacated space so that aproximal surface18 can be positioned adjacent to the tibial distal surface3, and thetalar component14 can be inserted into the vacated space so that adistal surface20 is positioned adjacent to the talarproximal surface5.
• Thetibial component12 can comprise an attachment profile on itsproximal surface18 that can correspond to a mating profile of the tibial distal surface3. One of the profiles of thetibial component12 and the tibial distal surface3 can comprise a male feature and the other can comprise a mating female feature. The attachment profile of thetibial component12 can include at least one male feature. The male feature can comprise arail22 protruding from theproximal surface18 of thetibial component12. The mating profile of the tibial distal surface3 can comprise at least one mating female feature, including arecess24 sized to receive the projectingrail22.
• Similarly, thetalar component14 can comprise an attachment profile at itsdistal surface20 that can correspond to a mating profile of the talarproximal surface5. One of the profiles of thetalar component14 and the talarproximal surface5 can comprise a male feature and the other can comprise a mating female feature. The attachment profile of thetalar component14 can include at least one male feature. The male feature can comprise arail26 protruding from thedistal surface20 of thetalar component14. The mating profile of the talarproximal surface5 can comprise at least one mating female feature, including arecess28 sized to receive the projectingrail26. Male features other than rails, such as ribs, fins, or keels, can also be used for thetibial component12, thetalar component14, or both.
• The bearingcomponent16 can be coupled or attached to thetibial component12 or to thetalar component14. The bearingcomponent16 can be attached to eithercomponent12,14 with a mechanical attachment device, such a snap fit between the bearingcomponent16 and thetibial component12 or thetalar component14,
• Bone cement can be applied between a prosthetic component of an implant and a corresponding bone to which the component is attached. For example, as illustrated inFIG. 2, abone cement30 can be applied between thetibial component12 and thetibia2, or between thetalar component14 and the talus4, or both. Using the present teachings, thebone cement30 can advantageously be applied only to localized, desired locations between eachcomponent12,14 and thecorresponding bone2,4. For example, thebone cement30 can be applied in an interface between male features and female features of theprosthetic components12,14 andbones2,4. Therecesses24,28 can be prepared and sized so that they provide space for therails22,26, with additional space to form a cavity for thebone cement30. Such additional spaces can be shaped and sized in any suitable manner to suit a particular orthopedic application. For example, the female-like void space21 shown in FIG.2 substantially mimics the shape of the rail so as to provide a substantially uniform thickness to the void space surrounding the rail. Thebone cement30 can be applied only or substantially only withinrecesses24,28 respectively existing between a projectingrail22 of thetibial component12 and the tibial distal surface3 and between a projectingrail26 of thetalar component14 and the talarproximal surface5. This sort of limited and targeted application of bone cement and/or other void-filling biocompatible material at the implantation site can be particularly useful in situations as described herein below where a highly porous, bone ingrowth-receptive material provides bone-contactingsurfaces18,20 and rails22,26. In this regard, the cement or other void-filling material can help to facilitate attachment of the implant to the surrounding bone while also leaving substantial portions of the highly porous, bone-contacting surfaces free of cement or filler and directly open to bone ingrowth.
• FIG. 3 is an isometric view of a plurality of components of anankle implant10. As illustrated, one or more projectingrails22 can extend laterally across aproximal surface18 of atibial component12. At least one projectingrail22 can extend substantially entirely across a lateral width of thetibial component12. Similarly, one or more projectingrails26 can extend laterally across adistal surface20 of thetalar component14. Al least one projectingrail26 can extend substantially entirely across a lateral width of thetalar component14. Theankle implant10 can further comprise abearing component16 positioned between thetibial component12 and thetalar component14. The bearingcomponent16 can provide an articulating surface to theankle implant10. Other configurations of male features and female features can be used. For example, rather than laterally projectingrails22,26, thecomponents12,14 can include rails, ribs, fins, or keels that extend from the anterior to the posterior and the corresponding recesses formed in thetibia12 and thetalus14 can be formed to extend from the anterior to the posterior.
• FIG. 4 is a schematic view of atibial component12, atalar component14, and abearing component16 of anankle implant10 inserted into apatient1, such as through anincision32 in a leg of thepatient1.Bone cement30 can be locally applied using acement applicator34, such as a syringe or a dispenser comprising an applicator nozzle36, on or in a feature of a prosthetic component or a bone to which the prosthetic component is to be attached. The space between thetibial component12 and thetibia2, or between thetalar component14 and the talus4, or both, can be small, e.g., as small as from1 millimeter to2 millimeters. Thecement applicator34 allows a surgeon or other medical practitioner to precisely and locally applybone cement30 within the small space, such as inrecesses24,28 and/or onrails22,26. In the example of theankle implant10 illustrated inFIG. 4, thecement applicator34 can be used to apply thebone cement30 into therecesses24 to affix thetibial component12 to thetibia2 and into therecesses28 to affix thetalar component14 to the talus4.
• Thetibial component12, thetalar component14, and abearing component16, if included, can be inserted into a vacated space between thetibia2 and the talus4. Eachcomponent12,14 can be positioned or aligned with respect to thebone2,4 to which it is to be affixed (e.g., so that a position or alignment of theprosthetic component12,14 with respect to thebone2,4 is substantially similar to a desired final position or alignment) before applying thebone cement30. For example, after being inserted into thepatient1, thetibial component12 can be positioned and aligned with respect to thetibia2 or with respect to thetalar component14. A frame, jig, or other support means can be used to maintain the relative position of thetibial component12 with respect to thetibia2 or thetalar component14. Thecement applicator34 can be used to dispense thebone cement30 into the cavity or space formed between therecesses24 and the projecting rails22. Similarly, after being inserted into thepatient1, thetalar component14 can be positioned and aligned with respect to the talus4 or with respect to thetibial component12. A frame, jig, or other support means can be used to maintain the relative position of thetalar component14 with respect to the talus4 or thetibial component12. The frame, jig, or other support means that is used with thetalar component14 can be the same or different frame, jig, or other support means that is used with thetibial component12. Thecement applicator34 can be used to dispense thebone cement30 into the space between therecesses28 and the projecting rails26.
• In an example, the mating profiles in thetibia2 and the talus4 can be formed so that an interference fit can be formed between the attachment profile of thetibial component12 and the mating profile of thetibia2, or between the attachment profile of thetalar component14 and the mating profile of the talus4. An interference fit can allow thecomponents12,14 to remain in a desired alignment relative to acorresponding bone2,4 without the need of a frame, jig, or other support means. A user can place thecomponent12,14 in position and align thecomponent12,14 relative to thebone2,4, and then engage thecomponent12,14 with the bone so that the interference fit can form. The interference fit can then hold thecomponent12,14 in place and maintain the alignment until thebone cement30 can be applied.
• For example, an interference fit can be created by forming therecesses24 and28 in thetibia2 and talus4, respectively, to have a width at one or more positions that is slightly larger than a corresponding width of the corresponding projectingrail22 or26. In an example, an interference fit can be formed between a male feature and a female feature if a width at one or more positions of the female feature, such as therecesses24,28, is within0.5 millimeters (mm) (about 0.0197 inches) of a width at a corresponding one or more positions of the male feature, such as therails22,26. The interference fit can also be formed if a width at one or more positions of the female feature is within 0.45 mm (about 0.018 inches), within 0.4 mm (about 0.0157 inches), within 0.35 mm (about 0.014 inches), within 0.34 mm (0.0134 inches), within 0.33 mm (about 0.13 inches), within 0.32 mm (about 0.0126 inches), within 0.31 mm (about 0.0122 inches), or within 0.3 mm (about 0.0118 inches), such as about 0.28 mm (about 0.011 inches).
• The attachment profile or a portion of the attachment profile of thecomponents12,14 can also be formed from a material or have a structure that provides for an interference-type of attachment to bone, such as a porous scaffold, for example a porous metal such as porous tantalum. One or more of therails22,26, or at least a portion of thesurfaces18,20, or both, can be formed from a porous scaffold (e.g., a highly porous scaffold) to facilitate attachment of thecomponents12,14 to thetibia2 and the talus4, respectively. In an example, substantially all ofsurfaces18,20 and rails22,26 can be formed of a porous metal material. The porous metal material can be bonded (e.g., diffusion bonded) or otherwise attached to a metal substrate that forms the remainder of eachcomponent12,14. For example, as probably best shown inFIG. 3,tibial component12 in this particular illustrative embodiment, can include a base tibial-side substrate23 that is fused (e.g., welded) or otherwise coupled to a highly porous, bone ingrowth-receptive structure25 which in this instance provides bone-contactingsurfaces18 and rails22. Likewise,talar component14 can include a base talar-side substrate27 that is bonded to a highly porous, bone ingrowth-receptive structure29 which in this particular instance provides bone-contactingsurfaces20 and rails26. Examples of materials that can be used to make a substrate (e.g.,substrates23 and27) to which a porous metal scaffold, such as a porous tantalum scaffold, is coupled include, but are not limited to, titanium (Ti), cobalt-chrome (CoCr), tantalum and alloys thereof such as cobalt chromium molybdenum. According to an exemplary embodiment of the present disclosure, the substrate may be a Ti-6Al-4V alloy, such as Tivanium® which is available from Zimmer, Inc., of Warsaw, Ind. Tivanium® is a registered trademark of Zimmer, Inc.
• Highly porous metal structures such asstructures25 and29 can incorporate one or more of a variety of biocompatible metals. Such structures are particularly suited for contacting bone and soft tissue, and in this regard, can be useful as a bone substitute and as cell and tissue receptive material, for example, by allowing cells and tissue to grow into the porous structure over time to enhance fixation (i.e., osseointegration) between the structure and surrounding bodily structures. Bone cements and other biocompatible void-filling materials disclosed herein can also interdigitate into the pores of these highly porous structures to facilitate attachment of these structures to surrounding bone and/or other implant components. According to certain embodiments of the present disclosure, an open porous metal structure may have a porosity as low as 55%, 65%, or 75% or as high as 80%, 85%, or 90%, or within any range defined between any pair of the foregoing values. An example of an open porous metal structure is produced using Trabecular Metal™ Technology available from Zimmer, Inc., of Warsaw, Ind. Trabecular Metal™ is a trademark of Zimmer, Inc. Such a material may be formed from a reticulated vitreous carbon foam substrate which is infiltrated and coated with a biocompatible metal, such as tantalum, by a chemical vapor deposition (“CVD”) process in the manner disclosed in detail in U.S. Pat. No. 5,282,861 and in Levine, B. R., et al., “Experimental and Clinical Performance of Porous Tantalum in Orthopedic Surgery”, Biomaterials 27 (2006) 4671-4681, the disclosures of which are expressly incorporated herein by reference. In addition to tantalum, other biocompatible metals may also be used in the formation of a highly porous metal structure such as titanium, a titanium alloy, cobalt chromium, cobalt chromium molybdenum, tantalum, a tantalum alloy, niobium, or alloys of tantalum and niobium with one another or with other metals. It is also within the scope of the present disclosure for a porous metal structure to be in the form of a fiber metal pad or a sintered metal layer, such as a Cancellous-Structured Titanium™ (CSTi™) layer. CSTi™ porous layers are manufactured by Zimmer, Inc., of Warsaw, Ind. Cancellous-Structured Titanium™ and CSTi™ are trademarks of Zimmer, Inc.
• Generally, a highly porous metal structure will include a large plurality of metallic ligaments defining open voids (i.e., pores) or channels therebetween. The open spaces between the ligaments form a matrix of continuous channels having few or no dead ends, such that growth of soft tissue and / or bone through open porous metal is substantially uninhibited. Thus, the open porous metal may provide a lightweight, strong porous structure which is substantially uniform and consistent in composition, and provides a matrix (e.g., closely resembling the structure of natural cancellous bone) into which soft tissue and bone may grow to provide fixation of the implant to surrounding bodily structures. According to some aspects of the present disclosure, exterior surfaces of an open porous metal structure can feature terminating ends of the above-described ligaments. Such terminating ends can be referred to as struts, and they can generate a high coefficient of friction along an exposed porous metal surface. Such features can impart an enhanced affixation ability to an exposed porous metal surface for adhering to bone and soft tissue. Also, when such highly porous metal structures are coupled to an underlying substrate, a small percentage of the substrate may be in direct contact with the ligaments of the highly porous structure, for example, approximately 15%, 20%, or 25%, of the surface area of the substrate may be in direct contact with the ligaments of the highly porous structure.
• An open porous metal structure may also be fabricated such that it comprises a variety of densities in order to selectively tailor the structure for particular orthopedic applications. In particular, as discussed in the above-incorporated U.S. Pat. No. 5,282,861, an open porous metal structure may be fabricated to virtually any desired density, porosity, and pore size (e.g., pore diameter), and can thus be matched with the surrounding natural tissue in order to provide an improved matrix for tissue ingrowth and mineralization. According to certain embodiments, an open porous metal structure may be fabricated to have a substantially uniform porosity, density, and/or void (pore) size throughout, or to comprise at least one of pore size, porosity, and/or density being varied within the structure. For example, an open porous metal structure may have a different pore size and/or porosity at different regions, layers, and surfaces of the structure. The ability to selectively tailor the structural properties of the open porous metal, for example, enables tailoring of the structure for distributing stress loads throughout the surrounding tissue and promoting specific tissue ingrown within the open porous metal.
• In other embodiments, an open porous metal structure may comprise an open cell polyurethane foam substrate coated with Ti-6Al-4V alloy using a low temperature arc vapor deposition process. Ti-6Al-4V beads may then be sintered to the surface of the Ti-6Al-4V-coated polyurethane foam substrate. Additionally, another embodiment of an open porous metal structure may comprise a metal substrate combined with a Ti-6Al-4V powder and a ceramic material, which is sintered under heat and pressure. The ceramic particles may thereafter be removed leaving voids, or pores, in the substrate. An open porous metal structure may also comprise a Ti-6Al-4V powder which has been suspended in a liquid and infiltrated, and coated on the surface of a polyurethane substrate. The Ti-6Al-4V coating may then be sintered to form a porous metal structure mimicking the polyurethane foam substrate. Further, another embodiment of an open porous metal structure may comprise a porous metal substrate having particles, comprising altered geometries, which are sintered to a plurality of outer layers of the metal substrate. Additionally, an open porous metal structure may be fabricated according to electron beam melting (EBM) and/or laser engineered net shaping (LENS). For example, with EBM, metallic layers (comprising one or more of the biomaterials, alloys, and substrates disclosed herein) may be coated (layer by layer) on an open cell substrate using an electron beam in a vacuum. Similarly, with LENS, metallic powder (such as a titanium powder, for example) may be deposited and coated on an open cell substrate by creating a molten pool (from a metallic powder) using a focused, high-powered laser beam.
• Examples of porous scaffolds for prosthetic implants, such as orthopedic bone restoration or joint repair implants, are described in the aforementioned U.S. Pat. No. 5,282,861 to Kaplan, entitled “Open Cell Tantalum Structures For Cancellous Bone Implants and Cell and. Tissue Receptors,” and U.S. Provisional Patent Application Ser. No. 61/653,510, entitled “ANISOTROPIC POROUS SCAFFOLDS,” filed on May 31, 2012, which are incorporated herein by reference in their entireties. A porous scaffold is available under the aforementioned trade name TRABECULAR METAL™ from Zimmer, Inc., Warsaw, Ind., USA, such as for orthopedic implants. The porous structure of a porous scaffold can also provide for cement adhesion to thecomponents12,14.
• Thecement applicator34 can comprise a needle or nozzle36 having a small cross-sectional width at a tip38, thereby allowing the tip38 and a portion of the needle or nozzle36 to fit within a profile feature of either a prosthetic component, such as thetibial component12 or thetalar component14, or a bone to which the prosthetic component is to be attached, such as thetibia2 or the talus4. In an example, the needle or nozzle36 is sized and shaped to fit into a recess formed between male and female features, such as between one of therails22 of thetibial component12 and acorresponding recess24 within thetibia2. The needle or nozzle36 can also be sized and shaped for insertion into a first lateral end of arecess24,28 and across the desired width to a medial end of therecess24,28.
• In addition to, or as an alternative tobone cement30, a variety of bioabsorbable and non-bioabsorbable void-filling materials can he delivered to recesses and other open spaces or voids that are provided adjacent a prosthetic component as disclosed herein such asrecesses24,28. Illustratively, thebone cement30 can be any adhesive material configured for adequately stabilizing a prosthetic component to a bone. An example bone cement is a polymeric bone cement, such as a polymethyl methacrylate (“PMMA”) cement. Thebone cement30 can be formed from acement precursor40 comprising one or more materials that undergo polymerization or cross-linking to form a solid or substantiallysolid bone cement30, when cured. Thecement precursor40 can be formed by mixing a liquid monomer with a particulate or powdered copolymer, After the liquid monomer and the copolymer are mixed and applied, the liquid monomer can undergo a polymerization reaction, such as a free-radical polymerization, to form the solid or substantiallysolid cement30.
• A liquid monomer that can be used is, but is not limited to, methyl methacrylate monomer. Examples of a particulate or powdered copolymer can include, but are not limited to, polymethyl methacrylate and methyl methacrylate-styrene. Other compounds, such as a polymerization initiator or a polymerization accelerator, can be mixed with the liquid monomer and the particulate or powdered copolymer when forming thecement precursor40,
• After being formed, thebone cement30 orcement precursor40 can be loaded into thecement applicator34 and dispensed between a prosthetic component and a bone. In an example, thecement precursor40 begins polymerizing, or setting, soon after the liquid polymer and the particulate or powdered copolymer are mixed. Alternatively, thecement precursor40 can remain substantially in liquid form for a period of time sufficient to apply it in desired void locations using thecement applicator34. In various examples, the materials forming thecement precursor40 are selected so that thebone cement30 will not set (e.g., will not be fully polymerized) for from about 3 minutes to about 5 minutes after mixing. Thebone cement30 orcement precursor40 can have a viscosity conducive to its application from a needle or nozzle36 having a profile or cross section that is sized and shaped to fit into a recess formed between male and female features, such as between one of therails22 of thetibial component12 and acorresponding recess24 within thetibia2. In an example, thecement precursor40 is configured so that the viscosity of thecement precursor40 remains below a threshold viscosity for at least a period of time that is sufficient to apply thecement precursor40 through thecement applicator34 into one or more desired locations, such as within arecess24,28. In an example, thecement precursor40 has a viscosity below the threshold viscosity for from about 3 minutes to about 5 minutes after thecement precursor40 is formed.
• The threshold viscosity that is acceptable can depend on several factors, including the geometry of thecement applicator34, the geometry of the needle or nozzle36 and the tip38, the geometry of the space into which thebone cement30 orcement precursor40 is to be applied, and the physical makeup of thebone cement30 or cement precursor40 (e.g., the particle size of the copolymer, the weight percent of the copolymer in the cement precursor mixture, or the composition and weight percent of additives in the cement precursor mixture).
• An example of asuitable bone cement30 that can be used is OSTEOBOND® copolymer bone cement, manufactured by Zimmer, Inc., of Warsaw, Ind., USA.
• The prosthetic component or components described herein, such as thetibial component12 and thetalar component14, can be combined in a kit with a cement applicator configured to apply a bone cement between the bone and the prosthetic component, following alignment of the prosthetic component with the bone, or engagement between the attachment profile of the prosthetic component and the mating profile of the bone, or both. The kit can also include a separate or integral sterile package for one or more of the kit components, such as the prosthetic component or components and the cement applicator. The kit can also comprise a bone cement or a cement precursor to be applied between the bone and the prosthetic component. The kit can also comprise a frame configured to maintain a position or an alignment of the prosthetic component with respect to the bone or with respect to a second prosthetic component. The kit can also include instructions for a user, such as to perform some or all of the steps of the method or methods described below.
• FIG. 5 is a flow chart of anexample method50 of affixing a prosthetic component, such as a tibial or talar component of an orthopedic ankle implant, to a bone, such as a tibia or a talus. Themethod50 can comprise, at52, exposing a portion of one or more bones to be modified (e.g., the tibia and the adjacent talus) by one or more prosthetic components, such as by cutting through the skin, muscle, and other tissue of a patient. At54, a profile in the bone can be formed to mate with an attachment profile of the prosthetic component. The profile in the bone can be a reverse or mirror image of the attachment profile of the prosthetic component. Forming the profile can comprise forming a feature in the bone that corresponds to a feature of the attachment profile of the prosthetic component, such as forming a female feature in the bone, such as a recess, configured to receive or mate with a male feature of the prosthetic component, such as a projecting rail, a fin, a rib, or a keel.
• At56, the prosthetic component can be positioned adjacent to the bone, and, at58, the prosthetic component can be aligned with respect to the bone or with respect to another prosthetic component. Positioning or aligning the prosthetic component allows a user to assure that an alignment or position of the prosthetic component with respect to the bone or with respect to the other prosthetic component is substantially the same as a desired final position or alignment of the prosthetic component, such as the desired position or alignment of the tibial component with respect to the tibia or the talar component after affixing the tibial component to the tibia. Positioning the prosthetic component can comprise inserting the prosthetic component into the patient, for example through an incision. Positioning the prosthetic component can also comprise engaging an attachment profile of the prosthetic component with the corresponding mating profile of the bone. The term “engaging,” as used herein with respect to a prosthetic component and a corresponding bone, can refer to positioning one or more features of the attachment profile of the prosthetic component so that they are in substantially the same position as a corresponding mating feature or features of the profile of the bone. For example, the prosthetic component can be positioned so that the attachment profile fits with the bone in a keyed relationship. As shown in the ankle implant ofFIGS. 1-4, the attachment profile of the tibial component can comprise one or more male features in the form of projecting rails, and the mating profile of the tibia can comprise a corresponding recess for each projecting rail.
• After positioning or aligning the prosthetic component, or both, themethod50 can include, at60, a bone cement can be applied between a portion of the positioned or aligned prosthetic component and the bone. Application of the bone cement can comprise dispensing a cement precursor into a void between the attachment profile of the prosthetic component and the mating profile of the bone. The cement precursor can be applied in or on a feature of the bone, or in or on a feature of the prosthetic component, or both. At62, the prosthetic component can be affixed to the bone with the bone cement. The bone cement can be passively allowed to set or harden in order to affix the prosthetic component to the bone, or the bone cement can be actively set, such as with an activatable initiator, such as a photoinitiator.
• Application of the bone cement can comprise injecting or dispensing the cement precursor with a cement applicator, such as the example applicator illustrated inFIG. 4. The cement applicator can be configured to dispense the cement precursor to a localized and desired location, such as between a rail of the tibial component and a recess in the tibia through a nozzle or a needle conduit and with little to no cement leakage. The cement applicator can allow for the application of the cement precursor after the tibial component, for example, has been inserted into the patient, positioned with respect to the tibia or the talar component, aligned with respect to the tibia or the talar component, yet still ensure that the cement precursor and the resulting bone cement is adequately applied at desired locations.
• Application of the cement precursor between the prosthetic component and the bone to which the prosthetic component is to be attached can comprise substantially filling a female feature of the prosthetic component and/or the hone with the cement precursor. In an example where a female feature comprises a recess, the method can comprise filling the recess substantially across an entire medial length of the recess with the cement precursor. Each female feature can be filled using a retrograde fill method. “Retrograde filling” can refer to a method where the bone cement or cement precursor is dispensed as the applicator is withdrawn from the female feature, such as by inserting the nozzle of the applicator into a first lateral end of the recess and across the lateral width of the recess to a second lateral end of the recess, followed by withdrawing the nozzle from the recess while concurrently dispensing the cement precursor through the nozzle. In an example, the cement precursor can be dispensed or prepared so that the female feature is substantially free of entrapped air.
• Themethod50 can further comprise forming the cement precursor prior to dispensing. Forming the cement precursor can comprise mixing a liquid monomer, such as methyl methacrylate, with a particulate or powdered copolymer, such as a powdered polymethyl methacrylate or a powdered methyl methacrylate-styrene. Other additives can he mixed with the monomer and the copolymer, such as a polymerization initiator or a polymerization accelerator. Mixing the liquid monomer and the particulate or powdered copolymer can result in a polymerization reaction, such as free-radical polymerization, to form a solid or substantially solid bone cement.
• Themethod50 can comprise loading the cement precursor into the cement applicator. In an example, loading the cement precursor into the cement applicator can include removing or evacuating any air from the cement applicator, such as by inverting the cement applicator and then dispensing the air and a small amount of the cement precursor from the cement applicator prior to applying the cement precursor between the prosthetic component and the bone.
• After applying the cement precursor between the prosthetic component and the bone, themethod50 can further comprise removing excess cement precursor or bone cement so that the excess bone cement does not interfere with operation of the implant or contaminate the surgical site. After the bone cement has set, stability, strength, or both, of the bone cement and the prosthetic component can be tested,
• FIG. 6 is a flow chart of anexample method70 of positioning an orthopedic ankle implant, for example, into a patient, to replace a joint. At72, a joint that is to be modified by one or more prosthetic components can be exposed.
• Exposing the ankle joint can comprise cutting through the patient's skin, muscle, and other tissue, and resecting and pulling back bodily tissue.
• At74 the joint can be prepared for modification, such as by cleaning out extraneous material or tissue. Preparing the joint can also include removing a portion of one or more bones, such as the tibia and the talus, in order to make room for one or more prosthetic components of the implant. Removing portions of the one or more bones can include stabilizing a patient's extremity of interest using a frame, jig, or other support apparatus, followed by cutting or resecting a portion of one or more of the bones.
• At76, at least one feature can be formed in a first bone of the joint. At78, at least one feature can be formed in a second bone of the joint. Each feature that is formed can correspond to an attachment feature of a corresponding prosthetic component.
• At80, a trial reduction of the prosthetic components can be performed, such as by inserting a temporary or trial version of each component of the final prosthetic implant into the patient to test for an acceptable size and geometry. In the case of an ankle implant, for example, a trial tibial component with a geometry similar to that of a final tibial component, a trial talar component with a geometry similar to that of a final talar component, and a trial bearing component with a geometry similar to that of a final bearing component can be inserted into the patient, positioned, and aligned in much the same way that final components can be aligned. A surgeon or other medical practitioner can then inspect the trial components and the corresponding bones to determine if the fit and alignment of the trial components is acceptable (e.g., ensuring that there is no lateral overhang of the trials beyond the tibia or the talus, ensuring that there is no bony impingement by the fibula., ensuring that the trial tibial component is substantially flush with the tibia, or ensuring that the trial talar component is substantially flush with the talus). If the fit or alignment of the trial components is not acceptable, the trial components can be removed, and one or more trial components of a different size or shape can be inserted or the bones can be further manipulated,
• At82, a first prosthetic component can be positioned in the patient so that each attachment profile feature of the first prosthetic component is adjacent to, or engaged with, a corresponding formed mating profile feature in the first bone. Similarly, at84, a second prosthetic component can be positioned in the patient so that each attachment profile feature of the second prosthetic component is adjacent to, or engaged with, a corresponding formed mating profile feature in the second bone. The first and second final prosthetic components that are selected and positioned within the patient can each have a geometry that is identical or substantially identical to a geometry of the corresponding trial component that was found to provide for an acceptable fit during the trial reduction, at80.
• At86, the first prosthetic component can be aligned with respect to a bone, such as the first bone, or with respect to another prosthetic component, such as the second prosthetic component. Similarly, at88, the second prosthetic component can be aligned with respect to a bone, such as the second bone, or with respect to another prosthetic component, such as the first prosthetic component. In the case of the ankle implant, for example, the tibial component can be aligned with respect to the tibia, with respect to the talar component, or with respect to the bearing component. Similarly, the talar component can be aligned with respect to the talus, with respect to the tibial component, or with respect to the bearing component. Aligning each component can comprise securing each component with one or more frames, jigs, or other securing apparatus to adjust and maintain the alignment of each component.
• At90, a bone cement or a cement precursor can be applied between the first prosthetic component and the first bone and. Similarly, at92, the bone cement or the cement precursor can be applied between the second prosthetic component and the second bone. In the case of the ankle implant, for example, the bone cement or the cement precursor can be applied between the tibial component and the tibia or between the talar component and the talus.
• At94, the bone cement between the first prosthetic component and the first bone can be set in order to affix the first prosthetic components to the first bone. Similarly, at96, the bone cement between the second prosthetic component and the second bone can be set in order to affix the second prosthetic component to the second bone. Setting the bone cement can comprise allowing the bone cement to set without active steps (e.g., allowing a cement precursor to polymerize and set as a solid or substantially solid bone cement to set). Alternatively, setting the bone cement can comprise actively causing or initiating setting via the use of a heat-activated cement precursor that begins setting upon the application of heat above an activation temperature or an ultraviolet-activated cement precursor that begins setting upon exposure to ultraviolet light of specified wavelength. While the cement precursor is setting to form the bone cement, the position and alignment of the prosthetic components with respect to the bones can be maintained, such as through continued use of a frame, jig, or other securing apparatus that holds one or more prosthetic components in position or alignment with respect to one or more bones or one or more other prosthetic components.
• The steps of themethod70 can generally be performed in any order, except where the ordering of steps is necessitated. For example, although the flow diagram ofFIG. 6 illustrates, at76, forming at least one feature in the first bone before forming at least one feature in the second bone, at78, these steps can be performed in a reverse order. Moreover, each step involving the first prosthetic component and the first bone can be performed in their entirety without performing the steps involving the second prosthetic component and the second bone, and vice versa. For example, a method can comprise, at76, forming at least one feature in the first bone, e.g., the tibia, corresponding to at least one mating feature in the first prosthetic component, e.g., the tibial component, then, at82, positioning the tibial component, e.g., adjacent to or engaged with the tibia, then, at86, aligning the tibial component with respect to the tibia or with respect to another prosthetic component, then, at90, applying a bone cement or cement precursor between the tibial component and the tibia, then, at94, setting the bone cement between the tibial component and the tibia. After completing these method steps with respect to the first prosthetic component, the method can then include performing the steps with respect to the second prosthetic component, e.g., at78, forming at least one feature in the second bone, e.g., the talus, corresponding to at least one mating feature of the second prosthetic component, e.g., the talar component, then, at84, positioning the talar component, e.g., adjacent to or engaged with the talus, then, at88, aligning the talar component with respect to the talus or with respect to another prosthetic component, then, at92, applying a bone cement or cement precursor between the talar component and the talus, then, at96, setting the bone cement between the talar component and the talus.
• With reference now toFIG. 7, shown is an example ankle implant similar to that shown inFIG. 2 except additionally incorporating astackable member100 stacked atoptibial component12.Stackable member100 can be formed with a variety of biocompatible implant materials, and in this particular illustrative embodiment is formed with a highly porous metallic material that is particularly adapted to receive bony ingrowth. Illustratively, at this particular treatment site, thetibial component12 includes an attachment profile on itsproximal surface18 that corresponds to a mating profile of adistal surface102 of thestackable member100, whereas thestackable member100 includes an attachment profile on itsproximal surface104 that corresponds to a mating profile of the tibial distal surface3. As discussed herein above, such profiles can incorporate cooperating male and female features. Male or male-type elements can include rails, ribs, fins, keels, and other projections. In this instance, male-type rails similar torails22 shown inFIG. 2 protrude from tibial componentproximal surface18 and from stackable memberproximal surface104. Female-type recesses are located in stackable member distal surface X and in tibial distal surface3 for accommodating the rails while leaving additional space to form a cavity for bone cement and/or another biocompatible filler material as similarly discussed elsewhere herein.
• Thetalar component14 is similar to that shown inFIG. 2, and includes an attachment profile with projecting rails at itsdistal surface20. These rails can be received in recesses in the talarproximal surface5 where the recesses can provide space for the rails with additional space for filler material(s). In an alternative embodiment, a second stackable member (not shown) can be stacked belowtalar component14. Such a member can be similar tomember100 except being ratable with the distal surface of thetalar component14 including its rails and with the talarproximal surface5 including its recesses. This second stackable member can be incorporated into the overall implant in addition to or instead ofstackable member100, and in this regard, it will be understood that, to suit a particular orthopedic application, any suitable number of successive stackable members can be stackedadjacent tibial component12 and/ortalar component14. Also, any two such stackable members in an implant arrangement can be the same or different in terms of physical characteristics such as but not limited to shape, size, thickness, and material(s) of construction.
• With reference now toFIG. 8, shown is an example of anankle fusion device110 according to one embodiment of the present disclosure. This and other fusion devices disclosed herein could be similar adapted for use elsewhere in the skeletal system including but not limited to in the foot, hand, and spine. This particular fusion device is formed with a highly porous metallic material that is particularly adapted to receive bony ingrowth although it can be formed with any number of suitable fusion-facilitating materials. Illustratively, at this particular treatment site, thefusion device110 includes an attachment profile on itsproximal surface112 that corresponds to a mating profile of the tibial distal surface3 and an attachment profile on itsdistal surface114 that corresponds to a mating profile of the talarproximal surface5. As discussed herein above, such profiles can incorporate cooperating male and female features. Male or male-type elements can include rails, ribs, fins, keels, and other projections. In this instance, male-type rails similar torails22 shown inFIG. 2 protrude from fusion deviceproximal surface112 and fromdistal surface114. Female-type recesses are located in tibial distal surface3 and talarproximal surface5 for accommodating the rails while leaving additional space to form a cavity for bone cement and/or another biocompatible filler material as similarly discussed elsewhere herein.
• In an alternative embodiment, one or more stackable members (not shown) similar to the stackable members discussed above in relation toFIG. 7 can be stacked atop fusion deviceproximal surface112 and/or one or more stackable members can be stacked below fusion devicedistal surface114 to provide a stacked, multi-part fusion device. Any suitable number of stackable fusion members can be employed in this regard to suit a particular orthopedic application. Illustratively, a first stackable member can be stacked atop fusion deviceproximal surface112 with the attachment profile of this proximal surface corresponding to a mating profile of a distal surface of the first stackable member. The first stackable member can then include an attachment profile on its proximal surface that corresponds to a mating profile of the tibial distal surface3. As discussed herein above, such profiles can incorporate a variety of cooperating male and female features including but not limited to rails and rail-accommodating recesses as shown inFIG. 8, Any two such stackable members in a stacked, multi-part fusion arrangement can be the same or different in terms of physical characteristics such as but not limited to shape, size, thickness, and material(s) of construction.
• To better illustrate the apparatus, kits, and methods and disclosed herein, a non-limiting list of examples is provided here:
• Example 1 can include subject matter (such as an apparatus, a device, a method, or one or more means for performing acts), such as can include a kit. The subject matter can comprise a prosthetic component including an attachment profile corresponding to a mating profile formed on or in a bone, and a cement applicator configured to apply a bone cement between the bone and the prosthetic component, following alignment between the prosthetic component and the bone or another prosthetic component.
• Example 2 can include, or can optionally be combined with the subject matter of Example 1, to optionally include the prosthetic component being a first prosthetic component and the bone being a first bone.
• Example 3 can include, or can optionally be combined with the subject matter of one or any combination of Examples 1 or 2, to optionally include a second prosthetic component including an attachment profile corresponding to a mating profile formed in a second bone.
• Example 4 can include, or can optionally be combined with the subject matter of one or any combination of Examples 1-3, to optionally include the first prosthetic component and the second prosthetic component forming at least a portion of a prosthetic joint.
• Example 5 can include, or can optionally be combined with the subject matter of one or any combination of Examples 1-4, to optionally include the prosthetic joint includes at least one of a prosthetic ankle joint, a prosthetic wrist joint, a prosthetic elbow joint, a prosthetic knee joint, a prosthetic hip joint, a prosthetic shoulder joint, a prosthetic finger joint, and a prosthetic toe joint.
• Example 6 can include, or can optionally be combined with the subject matter of one or any combination of Examples 1-5, to optionally include the cement applicator including a conduit sized and shaped to apply the bone cement into a void between the bone and the prosthetic component.
• Example 7 can include, or can optionally be combined with the subject matter of one or any combination of Examples 1-6, to optionally include a frame configured to maintain a position or an alignment of the prosthetic component with respect to the bone or with respect to a second prosthetic component.
• Example 8 can include, or can optionally be combined with the subject matter of one or any combination of Examples 1-7, to optionally include one or more components of the bone cement to be loaded into the cement applicator.
• Example 9 can include, or can optionally be combined with the subject matter of one or any combination of Examples 1-8, to optionally include a precursor of the bone cement including a liquid monomer and a particulate copolymer.
• Example 10 can include, or can optionally be combined with the subject matter of one or any combination of Examples 1-9, to optionally include instructions for using the prosthetic component and the cement applicator.
• Example 11 can include, or can optionally be combined with the subject matter of one or any combination of Examples 1-10, to optionally include the instructions reciting the steps of positioning the prosthetic component adjacent to the bone, aligning the prosthetic component with respect to the bone or with respect to another prosthetic component, and applying the bone cement between the bone and the aligned prosthetic component.
• Example 12 can include, or can optionally be combined with the subject matter of one or any combination of Examples 1-11, to optionally include the instructions further reciting forming the mating profile in the bone by forming a male projecting feature or a female receiving feature.
• Example 13 can include, or can optionally be combined with the subject matter of one or any combination of Examples 1-12, to optionally include the instructions for applying the bone cement reciting applying the bone cement onto the male projecting feature or into the female receiving feature after aligning the prosthetic component with respect to the bone or with respect to the other prosthetic component.
• Example 14 can include, or can optionally be combined with the subject matter of one or any combination of Examples 1-13, to optionally include the instructions further reciting a step of maintaining the alignment of the prosthetic component with respect to the bone or with respect to the other prosthetic component while applying the bone cement between the prosthetic component and the bone.
• Example 15 can include, or can optionally be combined with the subject matter of one or any combination of Examples 1-14, to include subject matter (such as an apparatus, a device, a method, or one or more means for performing acts), such as can include a method of implant. The subject matter can include positioning a prosthetic component adjacent to a bone, aligning the prosthetic component with respect to the bone or with respect to another prosthetic component, and applying a bone cement between the bone and the aligned prosthetic component.
• Example 16 can include, or can optionally be combined with the subject matter of one or any combination of Examples 1-15, to optionally include forming a bone feature on or in the bone, wherein the bone feature corresponds to an attachment profile of the prosthetic component.
• Example 17 can include, or can optionally be combined with the subject matter of one or any combination of Examples 1-16, to optionally include the forming the bone feature including forming a male projecting feature or a female receiving feature.
• Example 18 can include, or can optionally be combined with the subject matter of one or any combination of Examples 1-17, to optionally include the applying the bone cement including applying the bone cement onto the male projecting feature or into the female receiving feature after aligning the prosthetic component with respect to the bone or with respect to the other prosthetic component.
• Example 19 can include, or can optionally be combined with the subject matter of one or any combination of Examples 1-18, to optionally include the applying the bone cement including injecting the bone cement through a conduit of a cement applicator and into or around a void between the bone and the aligned and attached prosthetic component.
• Example 20 can include, or can optionally be combined with the subject matter of one or any combination of Examples 1-19, to optionally include the applying the bone cement including applying the bone cement in a retrograde direction.
• Example 21 can include, or can optionally be combined with the subject matter of one or any combination of Examples to optionally include the attaching the prosthetic component to the bone including forming at least a portion of a prosthetic joint selected from a prosthetic ankle joint, a prosthetic mist joint, a prosthetic elbow joint, a prosthetic knee joint, a prosthetic hip joint, a prosthetic shoulder joint, a prosthetic finger joint, and a prosthetic toe joint.
• Example 22 can include, or can optionally be combined with the subject matter of one or any combination of Examples 1-21, to optionally include forming the bone cement, including mixing a monomer and a particulate copolymer or a cement powder.
• Example 23 can include, or can optionally be combined with the subject matter of one or any combination of Examples 1-22, to optionally include maintaining the alignment of the prosthetic component with respect to the bone or with respect to the other prosthetic component while applying the bone cement between the bone and the prosthetic component.
• Example 24 can include, or can optionally be combined with the subject matter of one or any combination of Examples 1-23, to include subject matter (such as an apparatus, a device, a method, or one or more means for performing acts), such as can include a kit. The subject matter can include a prosthetic device for positioning adjacent to a bone and aligning with respect to the bone or with respect to another prosthetic device, and cement for applying between the bone and the aligned prosthetic device.
• The above detailed description includes references to the accompanying drawings, which form a part of the detailed description. The drawings show, by way of illustration, specific embodiments in which the invention can be practiced. These embodiments are also referred to herein as “examples.” Such examples can include elements in addition to those shown or described. However, the present inventors also contemplate examples in which only those elements shown or described are provided. Moreover, the present inventors contemplate examples using any combination or permutation of those elements shown or described (or one or more aspects thereof), either with respect to a particular example (or one or more aspects thereof), or with respect to other examples (or one or more aspects thereof) shown or described herein.
• In this document, the terms “a” or “an” are used, as is common in patent documents, to include one or more than one, independent of any other instances or usages of “at least one” or “one or more.” In this document, the term “or” is used to refer to a nonexclusive or, such that “A or B” includes “A but not B,” “B but not A,” and “A and B,” unless otherwise indicated. In this document, the terms “including” and “in which” are used as the plain-English equivalents of the respective terms “comprising” and “wherein.” Also, in the following claims, the terms “including” and “comprising” are open-ended, that is, a system, device, article, kit, composition, formulation, or process that includes elements in addition to those listed after such a term in a claim are still deemed to fall within the scope of that claim. Moreover, in the following claims, the terms “first,” “second,” and “third,” etc. are used merely as labels, and are not intended to impose numerical requirements on their objects.
• The above description is intended to be illustrative, and not restrictive. For example, the above-described examples (or one or more aspects thereof) may be used in combination with each other. Other embodiments can be used, such as by one of ordinary skill in the art upon reviewing the above description. Also, various features or elements can be grouped together to streamline the disclosure. This should not be interpreted as intending that an unclaimed disclosed feature is essential to any claim. Rather, inventive subject matter can lie in less than all features of a particular disclosed embodiment. Thus, the following claims are hereby incorporated into the detailed description, with each claim standing on its own as a separate embodiment. The scope of the invention should be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled.
• The Abstract is provided to comply with 37 C.F.R. §1.72(b), to allow the reader to quickly ascertain the nature of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims.

Claims (21)

1.-20. (canceled)

21. A prosthesis positionable between a first bone surface and a second bone surface in a patient, comprising:

a prosthetic tibial component comprising:

a first attachment feature having a first attachment profile that is associable with a mating profile of the first bone surface in a male-female mating relationship; and

a first articular surface;

a prosthetic talus component comprising:

a second attachment feature having a second attachment profile that is associable with a mating profile of the second bone surface in a male-female mating relationship; and

a second articular surface; and

a bearing component positionable between the first articular surface of the prosthetic tibial component and the second articular surface of the prosthetic talus component.

22. The prosthesis ofclaim 21, wherein the first attachment feature and the second attachment feature each extends uninterruptedly from a first end to a second end.

23. The prosthesis ofclaim 22, wherein the first attachment feature and the second attachment feature each comprises an elongated rail having a solid cross-section entirely formed of highly porous metal.

24. The prosthesis ofclaim 22, wherein the first attachment feature and the second attachment feature extend across an entirety of the prosthetic tibial component and the prosthetic talus component, respectively.

25. The prosthesis ofclaim 21, wherein the attachment profile comprises a mushroom-shaped cross-sectional profile.

26. The prosthesis ofclaim 21, wherein the first articular surface is concave and the second articular surface is convex.

27. The prosthesis ofclaim 26, wherein the second articular surface subtends an arc segment greater than the first articular surface.

28. The prosthesis ofclaim 21, wherein:

the prosthetic tibial component and the prosthetic talus component each comprises:

a bearing-side substrate formed of a non-porous material; and

a bone-engaging structure attached to the bearing-side substrate and including the first or second attachment feature, the bone-engaging structure comprising a porous material; and

the bearing component comprises a polymeric material.

29. The prosthesis ofclaim 21, wherein the bearing component is couplable to either the prosthetic tibial component or the prosthetic talus component.

30. The prosthesis ofclaim 29, wherein the bearing component is snap-fit to the prosthetic tibial component.

31. A prosthetic ankle implant comprising:

a bone-engaging component comprising:

a bone-engaging structure;

a first attachment feature projecting from the bone-engaging structure; and

a bearing-side substrate attached to the bone-engaging structure opposite the first attachment feature; and

a bearing component positionable against the bearing-side substrate.

32. The prosthetic ankle implant ofclaim 31, wherein:

the bone-engaging structure comprises a porous metallic material; and

the bearing component comprises a non-porous polymeric material.

33. The prosthetic ankle implant ofclaim 31, wherein the bone-engaging component is arcuate such that the bearing-side substrate is concave.

34. The prosthetic ankle implant ofclaim 33, wherein the bone-engaging component and the bearing component subtend arc segments of equal length.

35. The prosthetic ankle implant ofclaim 34, wherein the bone-engaging component is configured to join to a tibia.

36. The prosthetic ankle implant ofclaim 31, wherein the bone-engaging component is arcuate such that the bearing-side substrate is convex.

37. The prosthetic ankle implant ofclaim 36, wherein the bone-engaging component subtends an arc segment greater than an arc segment subtended by the bearing component.

38. The prosthetic ankle implant ofclaim 37, wherein the bone-engaging component is configured to join to a talus.

39. The prosthetic ankle implant ofclaim 31, wherein the first attachment feature comprises an elongated rail having a solid mushroom-like cross-sectional profile

40. The prosthetic ankle implant ofclaim 39, wherein the first attachment feature extends uninterruptedly from a first end to a second end across an entirety of the bone-engaging structure and is formed entirely of highly porous material.

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