WO2023064330A1 - Surfaces d'implant poreuses - Google Patents

Surfaces d'implant poreuses Download PDF

Info

Publication number
WO2023064330A1
WO2023064330A1 PCT/US2022/046372 US2022046372W WO2023064330A1 WO 2023064330 A1 WO2023064330 A1 WO 2023064330A1 US 2022046372 W US2022046372 W US 2022046372W WO 2023064330 A1 WO2023064330 A1 WO 2023064330A1
Authority
WO
WIPO (PCT)
Prior art keywords
implants
zirconium
porous
oxidation process
regions
Prior art date
Application number
PCT/US2022/046372
Other languages
English (en)
Inventor
Ruxandra Cristiana Marinescu TANASOCA
Darren J. Wilson
John Rose
Original Assignee
Smith & Nephew, Inc.
Smith & Nephew Orthopaedics Ag
Smith & Nephew Asia Pacific Pte. Limited
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Smith & Nephew, Inc., Smith & Nephew Orthopaedics Ag, Smith & Nephew Asia Pacific Pte. Limited filed Critical Smith & Nephew, Inc.
Publication of WO2023064330A1 publication Critical patent/WO2023064330A1/fr

Links

Classifications

    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61F—FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
    • A61F2/00—Filters implantable into blood vessels; Prostheses, i.e. artificial substitutes or replacements for parts of the body; Appliances for connecting them with the body; Devices providing patency to, or preventing collapsing of, tubular structures of the body, e.g. stents
    • A61F2/02—Prostheses implantable into the body
    • A61F2/30—Joints
    • A61F2/3094—Designing or manufacturing processes
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61F—FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
    • A61F2/00—Filters implantable into blood vessels; Prostheses, i.e. artificial substitutes or replacements for parts of the body; Appliances for connecting them with the body; Devices providing patency to, or preventing collapsing of, tubular structures of the body, e.g. stents
    • A61F2/02—Prostheses implantable into the body
    • A61F2/30—Joints
    • A61F2/30767—Special external or bone-contacting surface, e.g. coating for improving bone ingrowth
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61L—METHODS OR APPARATUS FOR STERILISING MATERIALS OR OBJECTS IN GENERAL; DISINFECTION, STERILISATION OR DEODORISATION OF AIR; CHEMICAL ASPECTS OF BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES; MATERIALS FOR BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES
    • A61L27/00—Materials for grafts or prostheses or for coating grafts or prostheses
    • A61L27/02—Inorganic materials
    • A61L27/04—Metals or alloys
    • A61L27/047—Other specific metals or alloys not covered by A61L27/042 - A61L27/045 or A61L27/06
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61L—METHODS OR APPARATUS FOR STERILISING MATERIALS OR OBJECTS IN GENERAL; DISINFECTION, STERILISATION OR DEODORISATION OF AIR; CHEMICAL ASPECTS OF BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES; MATERIALS FOR BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES
    • A61L27/00—Materials for grafts or prostheses or for coating grafts or prostheses
    • A61L27/50—Materials characterised by their function or physical properties, e.g. injectable or lubricating compositions, shape-memory materials, surface modified materials
    • A61L27/56—Porous materials, e.g. foams or sponges
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61F—FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
    • A61F2/00—Filters implantable into blood vessels; Prostheses, i.e. artificial substitutes or replacements for parts of the body; Appliances for connecting them with the body; Devices providing patency to, or preventing collapsing of, tubular structures of the body, e.g. stents
    • A61F2/02—Prostheses implantable into the body
    • A61F2/30—Joints
    • A61F2/30767—Special external or bone-contacting surface, e.g. coating for improving bone ingrowth
    • A61F2002/3092—Special external or bone-contacting surface, e.g. coating for improving bone ingrowth having an open-celled or open-pored structure
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61F—FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
    • A61F2/00—Filters implantable into blood vessels; Prostheses, i.e. artificial substitutes or replacements for parts of the body; Appliances for connecting them with the body; Devices providing patency to, or preventing collapsing of, tubular structures of the body, e.g. stents
    • A61F2/02—Prostheses implantable into the body
    • A61F2/30—Joints
    • A61F2/3094—Designing or manufacturing processes
    • A61F2002/3097—Designing or manufacturing processes using laser
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61F—FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
    • A61F2310/00—Prostheses classified in A61F2/28 or A61F2/30 - A61F2/44 being constructed from or coated with a particular material
    • A61F2310/00005—The prosthesis being constructed from a particular material
    • A61F2310/00011—Metals or alloys
    • A61F2310/00035—Other metals or alloys
    • A61F2310/00089—Zirconium or Zr-based alloys
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61F—FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
    • A61F2310/00—Prostheses classified in A61F2/28 or A61F2/30 - A61F2/44 being constructed from or coated with a particular material
    • A61F2310/00005—The prosthesis being constructed from a particular material
    • A61F2310/00011—Metals or alloys
    • A61F2310/00035—Other metals or alloys
    • A61F2310/00131—Tantalum or Ta-based alloys
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61F—FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
    • A61F2310/00—Prostheses classified in A61F2/28 or A61F2/30 - A61F2/44 being constructed from or coated with a particular material
    • A61F2310/00005—The prosthesis being constructed from a particular material
    • A61F2310/00179—Ceramics or ceramic-like structures
    • A61F2310/00185—Ceramics or ceramic-like structures based on metal oxides
    • A61F2310/00239—Ceramics or ceramic-like structures based on metal oxides containing zirconia or zirconium oxide ZrO2
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61L—METHODS OR APPARATUS FOR STERILISING MATERIALS OR OBJECTS IN GENERAL; DISINFECTION, STERILISATION OR DEODORISATION OF AIR; CHEMICAL ASPECTS OF BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES; MATERIALS FOR BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES
    • A61L2430/00—Materials or treatment for tissue regeneration
    • A61L2430/02—Materials or treatment for tissue regeneration for reconstruction of bones; weight-bearing implants

Definitions

  • the present disclosure is directed to methods of forming porous regions on surfaces of implantable devices and to implantable devices that are formed using such methods.
  • the wrought forged components typically used in current generation total joint arthroplasty are fabricated from an alloy of 97.5% zirconium and 2.5% niobium (Zr-2.5Nb). They are oxidized in air at temperatures above 500°C. Thermal diffusion in an oxygen-rich environment, referred to hereafter as thermal graded oxidation (TGO), creates a hard implantable oxidized surface with a thickness of approximately 5 pm.
  • TGO thermal graded oxidation
  • An example of such a material is OXINIUMTM Oxidized Zirconium, OxZr (Smith and Nephew Inc., Memphis TN, USA).
  • the thermal diffusion process forms a uniform oxide even on complex-shaped components such as a femoral component of a total knee replacement, with a gradual transition from the surface ceramic oxide to substrate Zr-2.5Nb.
  • the resulting black ceramic oxide surface is an integral part of the material, as opposed to a surface coating, which is characterized by a weak coating-substrate interface, especially under mechanical strain and bending deformation.
  • the ceramic surface of OxZr caused by its chemical bond to the underlying substrate is also less susceptible to debonding or chipping than nitrogen- ion-implanted Ti-6A1-4V surfaces.
  • OxZr is used in the femoral component of the prosthesis due to its unique properties of having a ceramic surface with the ductility of a metallic component. Consequently, OxZr reduces the incidence of abrasive and adhesive wear mechanisms and the accompanying release of debris.
  • OxZr femoral components rely on cemented fixation whereby horizontal splines located on the inside bone contacting surface are able to trap bone cement such as poly methyl methacrylate (PMMA), to facilitate mechanical fixation of the femoral component with bone.
  • PMMA poly methyl methacrylate
  • Cementless fixation in TKA has gained more and more popularity as a better alternative to cemented fixation.
  • the inner side of the femoral component i.e., the surface that is in contact with the bone, has a porous surface with porous characteristics as per Food and Drug Administration (FDA) requirements (see, e.g., FDA Guidance Document 1418, “Class II Special Controls Guidance Document: Knee Joint Patellofemorotibial and Femorotibial Metal/Polymer Porous-Coated Uncemented Prostheses; Guidance for Industry and FDA”, issued Jan 16, 2003).
  • FDA Guidance Document 1418 “Class II Special Controls Guidance Document: Knee Joint Patellofemorotibial and Femorotibial Metal/Polymer Porous-Coated Uncemented Prostheses; Guidance for Industry and FDA”, issued Jan 16, 2003).
  • Thermal porous plasma spraying is a low-temperature coating process used to create in-growth surfaces for cementless fixation. Plasma spray coatings applied to joint replacement prostheses are designed to encourage new bone formation around an implant, thereby improving fixation and long-term survivorship of the artificial joint.
  • the thermal porous plasma spray process utilizes melted (or heated) materials, i.e., "feedstocks" (coating precursors), which are sprayed directly onto a surface using a plasma jet as the energy carrier, which is produced by establishing a DC (direct current) arc between the electrode (cathode) and the nozzle (anode) with partial or total ionization of the plasma gas occurring.
  • the plasma gases commonly used are argon, hydrogen, helium, nitrogen, or mixtures thereof. By controlling the plasma gas composition, its thermal conductivity and viscosity can be adjusted.
  • the plasma jet heats the spray material, which may be injected into the plasma jet inside or outside the nozzle. The high velocity of the jet emerging from the nozzle and acceleration of the particles is generated by the thermal expansion of the plasma.
  • thermal porous plasma spraying for creating porous ingrowth surfaces.
  • it requires a line of sight to the surface being coated, similar to all other thermal spraying processes making it challenging to coat inner surfaces of small diameter bores and other restricted access surfaces.
  • the process is particularly challenging for parts with complex geometry, such as femoral components, which have special features that would block the line of sight, such as femoral pegs.
  • femoral components may have 4 or 5 faces that need coating with a uniform thickness. Most of the faces are inclined at different angles, which makes spraying inside a femoral component and maintaining uniform coating thickness difficult.
  • the size of the femoral components to be coated is another challenge, with smaller size of the femoral components preventing the spray gun from spraying all the inner surfaces.
  • the porosity of the coatings is also difficult to control due to the chaotic process associated with the buildup of the thermal spray coating. Particles overheated in the spray jet can become oxidized, and non-melted particles may simply be embedded in the accumulating deposit, which can lead to particle shedding.
  • the methods herein provide a transformative process (re-melting and casting) to form integral porous regions having many structural patterns on ceramic oxide surfaces of zirconium-containing components of medical devices.
  • the present disclosure pertains to methods of forming porous regions on ceramic oxide surfaces of zirconium-containing components of medical devices.
  • the porous regions are formed by a process that comprises (a) using laser beam surface texturing or electron beam surface texturing to create one or more beam-textured regions in one more ceramic oxide surfaces of a zirconium-containing component of a medical device and, optionally, (b) subjecting the one or more beam-textured regions to a secondary oxidation process.
  • the present disclosure pertains to methods of forming one or more porous regions on ceramic oxide surfaces of zirconium-containing components of medical devices by masking one or more regions of the medical device and treating the device by an oxidation process to selectively create one or more porous regions in one more ceramic oxide surfaces of a zirconium-containing component of the medical device.
  • one or more porous regions are formed on one more ceramic oxide surfaces of a pure zirconium component.
  • one or more porous regions are formed on one more ceramic oxide surfaces of a zirconium alloy component.
  • zirconium alloys include those that comprise zirconium and one or more biocompatible elements such as niobium, titanium, molybdenum, silver, manganese or tantalum, among others.
  • one or more porous bone ingrowth regions may be formed on one more bone-interfacing ceramic oxide surfaces of a zirconium-containing component of an implantable device.
  • implantable devices that can be treated using such methods include knee implants, hip implants, shoulder implants, ankle implants, spinal implants, trauma implants, mid-shaft implants, arthrodesis implants, UniSpacers, and cartilage replacements, among others.
  • one or more porous bone ingrowth regions are formed on bone-interfacing ceramic oxide surfaces of a zirconium-containing femoral implant body (e.g., a femoral implant body configured for use in a total knee arthroplasty).
  • the ceramic oxide surface may be formed on the zirconium-containing component by thermal diffusion at elevated temperature in an oxy genrich environment.
  • laser beam texturing and/or electron beam texturing is performed such that an initial porous region is formed on the surface of the zirconium- containing component, wherein one or more of the following types of features are formed: bladelike protrusions, columnar protrusions, blind hole-type intrusions, blind slot-type intrusions, penetrating hole-type intrusions, penetrating slot-type intrusions, shaped protrusions of high aspect ratio in one elevation, curved blade-like protrusions, multi-faceted protrusions, angled protrusions, multi-faceted (i.e., intersecting) slot-type intrusions, curved intrusions, slot-type intrusions, and angled intrusions.
  • a porous region may be formed which has a 30-60% volume fraction of porosity, beneficially, a 50-60% volume fraction of porosity, a mean pore diameter ranging from 20 to 800 microns, and a coating thickness ranging from 20 to 2000 microns, among other values.
  • the porous regions are formed to meet FDA requirements for porous structures, including, for example, a porosity greater than 30% volume fraction, a mean pore size ranging from 100 to 100 microns and a coating thickness ranging from 500 to 1500 microns.
  • the secondary oxidation process is an electrolytic oxidation process, for example, a plasma electrolytic oxidation (PEO) process.
  • electrolytic oxidation process for example, a plasma electrolytic oxidation (PEO) process.
  • an existing porosity of the beam-textured surface is increased by the secondary oxidation process.
  • the secondary oxidation process may be used to form a porous region which has an average porosity ranging from a 30- 80% volume fraction of porosity, beneficially, a 70 to 80% volume fraction of porosity, a mean pore diameter ranging from 600 to 900 microns, and a thickness ranging from 1000 to 2000 microns, among other values.
  • the secondary oxidation process may be used to form a porous region having an oxide surface layer that ranges from 1000 to 2000 microns in thickness.
  • the secondary oxidation process may be used to incorporate an additional substance into the porous region.
  • the additional substance is a compound comprising calcium and phosphorous, for example, a calcium phosphate compound such as hydroxyapatite, among others.
  • the additional substance enhances the bioactivity of the porous region.
  • one or more surface areas of the zirconium- containing component are masked during the secondary oxidation process to preserve the characteristics of the ceramic oxide layer (e.g., bearing surfaces of an implant body may be masked). After the secondary oxidation process is completed, the masking material is removed.
  • one non-limiting technological advantage may include the ability to provide porous regions on zirconium-containing components, without the need for heating to high temperatures that degrade the properties of the zirconium-containing component.
  • Another non-limiting technological advantage may include the ability to provide porous regions on zirconium-containing components, without the need for thermal spraying processes, which can lead to a low tensile adhesion strength, poor porosity control and/or a non-uniform coating thickness .
  • Another non-limiting technological advantage may include the ability to provide bioactive porous regions on zirconium-containing components promoting durable long-term biologic fixation.
  • the methods herein produce an implantable medical device with one or more porous regions in one or more ceramic oxide surfaces of a zirconium-containing component surface of said implantable device.
  • the implantable medical device is selected from femoral implants, knee implants, hip implants, shoulder implants, ankle implants, spinal implants, trauma implants, mid-shaft implants, arthrodesis implants, UniSpacers, or cartilage replacements, among others.
  • FIG. 1 depicts a femoral component , in accordance with an example of the present disclosure.
  • FIG. 2 depicts a process of laser surface texturing, in accordance with an example of the present disclosure.
  • FIG. 3A schematically depicts how a laser beam can enable protrusions to be built and shaped in separate operations.
  • FIG. 3B is an electron micrograph showing a protrusion formed by laser texturing.
  • FIG. 4 illustrates various patterns that can be created using laser assisted texturing.
  • FIG. 5 A is a cross-sectional view of a laser-textured Zr-2Nb alloy surface, in accordance with an example of the present disclosure.
  • FIGS. 5B and 5C are images of electron beam-textured Oxinium coupons illustrating different density porous structures.
  • FIGS. 6 A and 6B depict porous network structures that are produced by additive manufacturing processes.
  • FIG. 7 schematically illustrates a metal implant body immersed in an electrolyte, in accordance with an example of the present disclosure.
  • FIGS. 8A-8C are images of a titanium surface in which surface topography is created by a secondary PEG process.
  • FIG. 9 schematically illustrates a process of forming a femoral implant in which a laser texturing process is used to create a porous surface, in accordance with an example of the present disclosure.
  • FIGS. 10A and 10B are schematic illustrations of a cross-section of a laser textured surface after PEG treatment, in accordance with an example of the present disclosure.
  • implantable devices and methods of forming the implantable devices will now be described more fully hereinafter with reference to the accompanying drawings, in which one or more features of the implantable devices and methods will be shown and described. It should be appreciated that the various features may be used independently of, or in combination, with each other. It will be appreciated that implantable devices and methods as disclosed herein may be embodied in many different forms and should not be construed as being limited to the examples set forth herein. Rather, these examples are provided so that this disclosure will convey certain features of the implantable devices and methods to those skilled in the art.
  • the present disclosure pertains to methods for forming porous regions on ceramic oxide surfaces of zirconium-containing components of implantable devices.
  • one or more porous bone ingrowth regions may be formed on one more bone-interfacing ceramic oxide surfaces of a zirconium-containing component of an implantable device.
  • implantable devices that can be made using such methods include knee implants, hip implants, shoulder implants, ankle implants, spinal implants, trauma implants, midshaft implants, arthrodesis implants, UniSpacers, and cartilage replacements, among others.
  • one or more porous regions are formed on one more ceramic oxide surfaces of a pure zirconium component of a medical device. In some examples, one or more porous regions are formed on one more ceramic oxide surfaces of a zirconium alloy component of a medical device.
  • zirconium alloys include those that comprise zirconium and one or more biocompatible elements such as niobium, titanium, molybdenum, silver, manganese or tantalum, among others (e.g., Zr-Nb, Zr-Ti, Zr-Mo, Zr-Ta, Zr-Zr-Nb-Zn, Zr-Mo-Zn, Zr-Nb-Ti, and Zr-Al-Fe-Nb alloys), with an alloy of 97.5% zirconium and 2.5% niobium (Zr-2.5Nb) being a particular example.
  • biocompatible elements such as niobium, titanium, molybdenum, silver, manganese or tantalum, among others (e.g., Zr-Nb, Zr-Ti, Zr-Mo, Zr-Ta, Zr-Zr-Nb-Zn, Zr-Mo-Zn, Zr-Nb-Ti, and Zr
  • the ceramic oxide surface may be formed on the zirconium-containing component, for example, by thermal diffusion at elevated temperature in an oxygen-rich environment.
  • the zirconium-containing component is fabricated from an alloy of 97.5% zirconium and 2.5% niobium (Zr-2.5Nb alloy) having a ceramic oxide surface, such as an OXINIUMTM Oxidized Zirconium implant body, in which the ceramic oxide surface is formed in air at temperatures above 500°C.
  • the zirconium-containing component corresponds to an implant body and the one or more porous regions correspond to one or more porous bone ingrowth regions of the implant body.
  • a zirconium-containing implant body is femoral implant body 5, like that shown in FIG. 1.
  • the bone-interfacing ceramic oxide surfaces of the femoral implant body 5, in which porous regions can be formed include two posterior flat surfaces (25) (one shown), two posterior chamfer surfaces (26) (one shown), one or two distal flat surfaces (27) (one shown), an anterior chamfer surface (28), an anterior flange surface (29), and two pegs (30) (one shown).
  • porous regions are formed on ceramic oxide surfaces of zirconium-containing components by a process that comprises (a) using laser or electron beam surface texturing to create one or more beam-textured regions in the one more ceramic oxide surfaces and (b) subjecting the one or more beam-textured regions to a post oxidation process, for example, an electrolytic oxidation process to increase surface bioactivity.
  • a wide variety of lasers are available including solid state lasers (e.g., ruby laser, neodymium-YAG (yttrium aluminum garnet) lasers, etc.), gas lasers (e.g., helium lasers, heliumneon lasers, CO2 lasers, etc.), excimer lasers, and dye lasers, among others.
  • solid state lasers e.g., ruby laser, neodymium-YAG (yttrium aluminum garnet) lasers, etc.
  • gas lasers e.g., helium lasers, heliumneon lasers, CO2 lasers, etc.
  • excimer lasers e.g., helium lasers, heliumneon lasers, CO2 lasers, etc.
  • dye lasers e.g., shifted laser surface texturing (sLST) in combination with hybrid polygonal laser beam scanning systems are particularly beneficial due to increased process speed and the ability to produce surfaces with precise periodical shapes and structures
  • sLST is a newly developed method, which has a potential to be at least 100 times more productive than traditional laser texturing with no heat accumulation effect and a virtually unlimited number of complex shape objects being producible with high precision on surfaces.
  • laser pulses are typically rapidly distributed across an entire surface by applying only one laser spot to one object at one repetition, with each repetition being slightly shifted on the surface and a sequence of shifts forming shapes of objects. Scanning is typically done along straight lines and laser pulsing is switched on continuously during processing of whole lines.
  • Laser beam texturing can generally operate under an ambient atmosphere, an inert atmosphere, a reducing atmosphere, an oxidizing atmosphere, or a vacuum, with an argon atmosphere being preferred in some examples to avoid surface oxidation.
  • Electron beam texturing is generally operated under vacuum.
  • Laser beam texturing can be operated in the following regimes, among others: continuous wave (CW) mode, quasi-continuous wave (QCW) stage, single pulsed (normal mode), single pulsed Q-switched mode, repetitively pulsed mode, nanosecond (NS) pulsed mode, picosecond (PS) pulsed mode, femtosecond (FS) pulsed mode, and mode locked.
  • CW continuous wave
  • QCW quasi-continuous wave
  • NS nanosecond
  • PS picosecond
  • FS femtosecond
  • Different laser beam pulse regimes nanosecond, picosecond and femtosecond
  • Different laser beam pulse regimes can be used to control the size and shape of the laser-ablated structures.
  • FIG. 2 schematically depicts a process in which a laser or electron beam 220 is focused through a lens 225 onto a surface at an interaction region 230, which is used to produce a series of beam-textured areas 240.
  • FIG. 3A schematically depicts how melting and moving material using a laser or electron beam can enable protrusions to be built and shaped in separate operations.
  • An energy beam (laser or electron beam) is used to locally melt the surface of the substrate and then to translate the molten material laterally. Multiple passes of the energy beam allow complex surface textures to be created. First an intense energy beam interacts with the surface, to distort the flat surface and create an intrusion. The energy beam is translated, and the molten material is translated laterally to form a protrusion. With several passes of the energy beam a sculpted surface is generated, with higher, taller features. In this way uniform and repeatable structure can be manufactured, with no adhesion issues of the features.
  • FIG. 3B is an electron micrograph showing how an overall structure 340 can be built and shaped into a structure having various nodules and grooves 340g.
  • FIG. 4 illustrates various regular or irregular patterns of bumps, dimples, and linear or non-linear grooves that can be created by beam texturing of a either titanium 6AL-4V alloy, cobalt chrome alloy or stainless-steel hip prostheses. Porous regions 400a, 400b of a hip prosthesis 400 are schematically illustrated at the center of FIG. 4.
  • FIG. 5A is a cross-sectional view of a laser-textured Zr-2Nb alloy surface, highlighting a porous structure that can be created by a beam texturing process. Different porous characteristics can be generated by varying key energy beam parameters: accelerating voltage (range: 60-100 kV), beam current (range: 5 - 15 mA), beam deflection parameters i.e., pattern, amplitude gain and frequency (Hz); etc.
  • FIG. 5B shows an Oxinium coupon with a surface texture created by electron-beam texturing to generate features (structures) with heights above 1 mm. However, the feature density was low.
  • FIG. 5A is a cross-sectional view of a laser-textured Zr-2Nb alloy surface, highlighting a porous structure that can be created by a beam texturing process. Different porous characteristics can be generated by varying key energy beam parameters: accelerating voltage (range: 60-100 kV), beam current (range: 5 - 15 mA), beam deflection parameters i.
  • 5C illustrates an improved surface texture created by slightly modifying the beam deflection parameters, amplitude (mA) and frequency (Hz).
  • Beam texturing can produce a surface texture with an average porosity of 55% ⁇ 3%, pore size of 551 ⁇ 31 microns, and a thickness of 1150 to 1300 microns, among other values.
  • the beam texturing process is capable of creating the following structures, which may positively influence bone on-growth: (a) high aspect ratio blade-like protrusions (typically -15:1, height: width), (b) high aspect ratio columnar protrusions (typically -10: 1, height: width), (c) blind hole-type intrusions, (d) blind slot-type intrusions, (e) penetrating hole-type intrusions, with burr- free edges on the penetrating side, (1) penetrating slot-type intrusions, with burr-free edges on the penetrating side, (g) shaped protrusions of high aspect ratio (e.g., -10-20:1, heightwidth) in one elevation, (h) curved blade-like protrusions, (i) multi-faceted protrusions, (j) angled protrusions, (k) multi-faceted (intersecting) slot-type intrusions, (k) curved, slot-type intrusions and (1) angled intrusions.
  • Electron beam processing can also create features approximately 500 pm in height using a laboratory 60kV, 4kW EB (electron beam) machine.
  • Beam texturing has the advantage of creating uniform and repeatable structures, and superior adhesion (>20MPa per ASTM Fl 044 and ASTM Fl 147) without requiring a third material, which could potentially adversely affect biocompatibility.
  • Beam surface texturing cannot currently achieve the size and shape of porous network structures that are produced by additive manufacturing processes, such as those shown FIGS. 6A and 6B (CONCELOCTM, Smith & Nephew Inc. TN, US). However, such structures must be bonded onto the implant body using traditional high-temperature process, which makes this very challenging for oxidized zirconium alloy materials.
  • the porosity of the beam textured surface is increased by subjecting the beam textured surface to a secondary oxidation process.
  • the oxidation process is an electrolytic oxidation process, such as a plasma electrolytic oxidation (PEO) process.
  • PEO is an electrochemical process of oxidation that is performed by creating microdischarges on the surface of components immersed in an electrolyte.
  • FIG. 7 schematically illustrates an implant body comprising a metal substrate 710 and having a porous ceramic oxide surface 715 immersed in an electrolyte 720 that is used in conjunction with the PEO process.
  • plasma discharge occurs at the metal/electrolyte interface when an applied voltage exceeds a certain critical breakdown value and appears as a number of discrete short-lived micro discharges moving across the surface.
  • This plasma discharge oxidizes the surface of the part and grows a nano-structured ceramic oxide layer from the metal substrate material.
  • the oxide film is produced by subsurface oxidation.
  • the oxidation may be performed at progressively higher voltages.
  • Advanced pulsed-current techniques are available which offer the potential for further dramatic improvements in process control and flexibility.
  • the PEO process can produce thick oxide coatings of varying porosity.
  • the PEO treatment has the advantage of being low cost while creating a uniform coating thickness.
  • advantages include; (a) minimal surface preparation, (b) application to substrates, including titanium, stainless steel, cobalt-chrome and zirconium alloys, which are shot-peened, grit-blasted, (c) formation of a hard, wear resistant surface, (d) enhanced corrosion resistance, (e) minimal impact on mechanical strength i.e., elastic modulus, of substrates, (f) flexibility in terms of strain tolerance, (g) good adhesion of the ceramic oxide layer to the underlying substrate, (h) the ability to coat inside cavities and complex shapes and (i) stable m-ZrCh and t-ZrCh phases can be formed on Zr-containing substrates.
  • the properties of the beam-textured surface may be enhanced by the PEO process in two ways.
  • surface macropores created by the beam texturing process may be etched by the PEO process creating more asperities for bone to interdigitate within the porous surface.
  • FIGS. 8A-8C are images highlighting the surface topographies that can be created in a standard, non- laser-ablated titanium surface using a PEO process by controlling the process parameters, with FIG. 8A showing a dense surface, FIG. 8B showing a more porous surface and FIG. 8C showing an etched surface.
  • Microparticles of magnesium or silica can also be incorporated in PEO electrolytic solution in order to enhance the porosity of the component in order to meet the FDA requirements for a bone-ingrowth surface.
  • Porosity percentages in PEO-processed, beam-textured surfaces may be in a range of 25-35% with a mean pore diameter ranging between 60-100 pm, which can be improved further by adjusting electrical and electrolyte parameters and repeating the PEO process (duplex).
  • the coating generated in the PEO process is principally the oxide of the underlying metal substrate
  • the coating can further include other species incorporated from the electrolyte.
  • the PEO process can be designed to introduce species such as Ca 2+ , Zn 2+ , P 3+ , and phosphate (PO4 3 ) into standard electrolytes to create a bioactive surface.
  • the electrolyte solution can be prepared using a calcium salt (e.g., calcium acetate or another calcium salt) and a phosphate salt (e.g., glycerophosphate disodium or another phosphate salt) in water (e.g., deionized water) (Type I or Type II).
  • HAP hydroxyapatite
  • Caio(P04)e(OH)2 is one example of a compound of calcium and phosphorus that may be formed. It is postulated that the biomimetic porous surface may dispense with the need for an additively manufactured 3D porous network, like that discussed above.
  • an additional substance such as those described above, is incorporated into the porous region or as a surface coating before (or instead of) the PEO processing. Methods for incorporating these additional substances are known in the art, and include for example, coating methods disclosed in U.S Pat. No. 8,821,911 and the like.
  • An increase in the PEO processing voltage increases the thickness of oxide coatings that are produced and the size of the pores in the coatings.
  • An increase in the PEO processing voltage also increases the amount of material that is introduced into the coatings from the electrolyte.
  • An increase in the voltage frequency of the PEO processing results in a reduced coating thickness and a reduced size of the largest pores, while increasing the amount of material that is introduced into the coatings from the electrolyte.
  • Increasing the overall time of PEO treatment results in an increase in coating thickness, an increase in coating porosity, an increase in the size of the pores in the coating, and an increase in the amount of material that is introduced into the coatings from the electrolyte.
  • Areas of the zirconium-containing component where it is desirable retain the original thermally grown oxide layer can be protected by either using a soft insulating mask (e.g., a mask of lacquer or wax material) or a hard insulating mask (e.g., a mask of stop-off tape, aluminium foil, glass or plastic tape or permanent masks molded from polyethylene, polypropylene, rubber or polyvinyl chloride (PVC)) to prevent plasma discharge from occurring in the masked areas during the PEO process.
  • the PEO process parameters e.g., the electrical regimes, electrolyte composition, processing tank geometry, etc.
  • the masking material is removed.
  • the present disclosure provides porous regions on ceramic oxide surfaces of zirconium-containing components of implantable devices, which have properties tailored for cementless fixation.
  • the porous regions are created by first subjecting the ceramic oxide surface of the zirconium-containing component to a laser or electron beam texturing process to create a textured surface that can support bone in-growth. Subsequently, the beam-textured surface is subjected to a secondary oxidation process, such as a PEO process, to enhance osseointegration by increasing the degree of interconnected porosity.
  • the secondary PEO process may also be used to create a biomimetic surface, which may have a calcium phosphate composition similar to the major inorganic component of natural bone.
  • aqueous electrolyte containing CsFENaOeP SFEO and (CHsCOCfhCa H2O during the PEO process e.g., pulse voltage 250-450 V, frequency 1000 Hz, duty cycle 60%, 1-3 min
  • the presence of calcium and phosphorous in the oxide layer may improve cell adhesion and proliferation and also stimulate the production of key marker proteins such as Runx2 (RUNX Family Transcription Factor 2) indicating differentiation of cells.
  • a wrought or forged Zr-2.5Nb alloy implant is heated in air above 500°C allowing oxygen to diffuse into the surface, transforming the metal surface into ceramic oxide. This creates oxy gen-enriched metal under ceramic oxide, which provides gradient properties.
  • the ceramic oxide surface is complemented with a tough, ductile metal interior.
  • One or more surfaces of the implant are then subjected to a laser- or electron-beam texturing process to create one or more porous regions.
  • bone-interfacing ceramic oxide surfaces of a femoral implant 905 can be subjected to a laser- or electron-beam texturing process to create the porous regions.
  • the bone-interfacing ceramic oxide surfaces in which porous regions can be formed include, one or two distal flat surfaces (927), an anterior chamfer surface (928), an anterior flange surface (929), two posterior chamfer surfaces (926) (a portion of one posterior chamfer surface is shown), two posterior flat surfaces (not shown), and two pegs (930).
  • portions of the posterior articular surface (931) and the anterior articular surface (933) which is illustrated as a glossy black ceramic oxide surface that has not been laser textured.
  • Critical areas of the resulting textured component e.g., articulating surfaces, such as the posterior articular surface, the distal articular surface, and the anterior articular surface, are then masked to protect them from plasma oxidation.
  • the unmasked portions of the component are then subjected to a PEO treatment using either a standard PEO electrolyte to provide interconnected pores 1042, as shown in FIG. 10A, or an electrolyte containing materials such as calcium- and phosphorous-containing compounds, to create interconnected pores that are doped with biomimetic materials 1044, 1046, as shown in FIG. 10B.
  • Standard electrolytes include Na2SiC>3 orNaOH electrolyte.
  • the functional properties of the resulting oxide coating depend on the synthesis conditions, including the electrolyte composition, the cathode and anode current densities, and the treatment time, among other factors.
  • stress caused by the formation and growth of the oxide film can arise because an oxide usually has a larger volume than that of the metal from which it is formed. If the oxide maintains crystallographic coherency with the underlying metal, then the oxide is in compression, while the metal is placed in tension. It is generally recognized that compressive stresses in coatings are more favorable than tensile stresses because they increase resistance to fatigue failure.
  • porous regions may be formed on ceramic oxide surfaces of zirconium-containing components by cold gas spraying.
  • Cold gas spraying is a solid-state process, which is able to provide a porous zirconium oxide coating on an underlying zirconium-containing component with minimal damage to the zirconium-containing component and minimal metallurgical changes at the interface between the two dissimilar materials.
  • cold gas spraying may be combined with PEO to meet the pore size and shape requirements per ASTM Fl 854.
  • distal may refer to the end farthest away from the medical professional/operator when introducing a device into a patient
  • proximal may refer to the end closest to the medical professional when introducing a device into a patient.
  • directional references do not necessarily create limitations, particularly as to the position, orientation, or use of this disclosure. As such, directional references should not be limited to specific coordinate orientations, distances, or sizes, but are used to describe relative positions referencing particular examples. Such terms are not generally limiting to the scope of the claims made herein. Any example or feature of any section, portion, or any other component shown or particularly described in relation to various examples of similar sections, portions, or components herein may be interchangeably applied to any other similar example or feature shown or described herein.
  • an "embodiment” or an “example” may refer to an illustrative representation of an environment or article or component in which a disclosed concept or feature may be provided or embodied, or to the representation of a manner in which just the concept or feature may be provided or embodied.
  • Such illustrated embodiments or examples are to be understood as examples (unless otherwise stated), and other manners of embodying the described concepts or features, such as may be understood by one of ordinary skill in the art upon learning the concepts or features from the present disclosure, are within the scope of the disclosure.
  • references to “one embodiment” or “one example” of the present disclosure are not intended to be interpreted as excluding the existence of additional embodiments or examples that also incorporate the recited features.
  • connection references e.g., engaged, atached, coupled, connected, and joined are to be construed broadly and may include intermediate members between a collection of elements and relative to movement between elements unless otherwise indicated. As such, connection references do not necessarily infer that two elements are directly connected and in fixed relation to each other.

Abstract

Dans divers exemples, la présente invention concerne des procédés de formation de régions poreuses sur des surfaces d'oxyde de céramique de composants de dispositif médical contenant du zirconium. Dans ces procédés, les régions poreuses sont formées par un procédé qui comprend (a) l'utilisation d'une texturation de surface par faisceau laser (220) ou d'une texturation de surface par faisceau d'électrons pour créer une ou plusieurs régions texturées par faisceau (240) dans une ou plusieurs surfaces d'oxyde céramique d'un composant contenant du zirconium d'un dispositif médical et, éventuellement, (b) la soumission de la ou des régions texturées par faisceau à un procédé d'oxydation secondaire. Dans certains exemples, de telles régions poreuses sont produites par un procédé d'oxydation électrolytique seul.
PCT/US2022/046372 2021-10-14 2022-10-12 Surfaces d'implant poreuses WO2023064330A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US202163255498P 2021-10-14 2021-10-14
US63/255,498 2021-10-14

Publications (1)

Publication Number Publication Date
WO2023064330A1 true WO2023064330A1 (fr) 2023-04-20

Family

ID=84359788

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/US2022/046372 WO2023064330A1 (fr) 2021-10-14 2022-10-12 Surfaces d'implant poreuses

Country Status (1)

Country Link
WO (1) WO2023064330A1 (fr)

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2003049781A1 (fr) * 2001-12-06 2003-06-19 Smith & Nephew, Inc. Surfaces structurees oxydees in situ pour protheses et procede de fabrication
US20050100578A1 (en) * 2003-11-06 2005-05-12 Schmid Steven R. Bone and tissue scaffolding and method for producing same
US20050171615A1 (en) * 2004-01-30 2005-08-04 Georgette Frederick S. Metallic bone implant having improved implantability and method of making the same
US8821911B2 (en) 2008-02-29 2014-09-02 Smith & Nephew, Inc. Coating and coating method
WO2021216336A1 (fr) * 2020-04-24 2021-10-28 Smith & Nephew, Inc. Implants médicaux fabriqués de manière additive, leurs procédés de formation et poudre d'alliage de zirconium utilisée pour les former

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2003049781A1 (fr) * 2001-12-06 2003-06-19 Smith & Nephew, Inc. Surfaces structurees oxydees in situ pour protheses et procede de fabrication
US20050100578A1 (en) * 2003-11-06 2005-05-12 Schmid Steven R. Bone and tissue scaffolding and method for producing same
US20050171615A1 (en) * 2004-01-30 2005-08-04 Georgette Frederick S. Metallic bone implant having improved implantability and method of making the same
US8821911B2 (en) 2008-02-29 2014-09-02 Smith & Nephew, Inc. Coating and coating method
WO2021216336A1 (fr) * 2020-04-24 2021-10-28 Smith & Nephew, Inc. Implants médicaux fabriqués de manière additive, leurs procédés de formation et poudre d'alliage de zirconium utilisée pour les former

Similar Documents

Publication Publication Date Title
de Viteri et al. Titanium and titanium alloys as biomaterials
US8337936B2 (en) Implant and method for manufacturing same
Shahali et al. Recent advances in manufacturing and surface modification of titanium orthopaedic applications
Narayanan et al. Strategies to improve the corrosion resistance of microarc oxidation (MAO) coated magnesium alloys for degradable implants: Prospects and challenges
EP1093384B1 (fr) Prothese orthopedique a revetement composite
US8268383B2 (en) Medical implant and production thereof
EP1453554B1 (fr) Surfaces structurees oxydees in situ pour protheses et procede de fabrication
EP1923079B1 (fr) Prothèse articulaire comprenant une partie métallique recouverte d'une céramique résistante à l'usure
US20040153154A1 (en) Bone implant and method for manufacturing same
US20050221259A1 (en) Dental or orthopaedic implant
US20070282432A1 (en) Implantable medical endoprostheses
US9259516B2 (en) Implant and method for manufacturing
EP1942961B1 (fr) Procédé de fabrication d'une couche de surface biocompatible à pores ouverts destinée à un implant.
JP2003260075A (ja) 多孔性金属足場
WO2009022911A2 (fr) Prothèse comprenant une surface d'interface osseuse anti-micromouvement, et son procédé de fabrication
CN101249279A (zh) 采用激光快速成形制备HA/Ti梯度生物活性材料的方法
Laketić et al. Surface modifications of biometallic commercially pure Ti and Ti-13Nb-13Zr alloy by picosecond Nd: YAG laser
CN106676605A (zh) 具有点阵结构多孔的纯钛或钛合金表面多孔生物活性陶瓷膜的制备方法及其应用
US11434570B2 (en) Coating method of apatite using laser
WO2023064330A1 (fr) Surfaces d'implant poreuses
Singh et al. Electrochemical and mechanical behavior of laser processed Ti–6Al–4V surface in Ringer’s physiological solution
Voinarovych et al. Fabrication and characterization of Zr microplasma sprayed coatings for medical applications
Brunette et al. Thermal spray coatings on titanium
DE10022162B4 (de) Zementfreies Implantat und Verfahren zur Herstellung eines zementfreien Implantats
Alontseva et al. Manufacturing and Characterization of Tantalum Microplasma Coatings for Biomedical Application

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 22806037

Country of ref document: EP

Kind code of ref document: A1