# US 12,005,616 B2 · Implantable medical device with varied composition and porosity, and method for forming same > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,005,616 B2 - Document ID: US12005616B2 - Status: Granted - Kind: B2 - Application number: 17/870,911 - Filed: 2022-07-22 - Published: 2023-03-23 - Granted: 2024-06-11 - Earliest claimed: 2020-09-11 - Assignees: Happe Spine LLC - Applicants: Happe Spine LLC - Inventors: Jeffery A. Farris; Kevin Lee Brown; Douglas B. Snell; Ryan K. Roeder; Mark G. Messman - Web page: https://patentgrep.com/patent/US12005616B2 ## CPC - B29C 43/006: {Pressing and sintering powders, granules or fibres} - A61F 2/28: Bones - A61F 2/3094: {Designing or manufacturing processes} - A61F 2/30942: {for designing or making customized prostheses, e.g. using templates, CT or NMR scans, finite-element analysis or CAD-CAM techniques} - A61F 2/30965: {Reinforcing the prosthesis by embedding particles or fibres during moulding or dipping} - A61L 27/46: with phosphorus-containing inorganic fillers - A61L 27/56: Porous materials, {e.g. foams or sponges} - B29C 43/003: {characterised by the choice of material} - B29C 67/202: {comprising elimination of a solid or a liquid ingredient} - C08J 9/0061: {characterized by the use of several polymeric components} - C08J 9/26: by elimination of a solid phase from a macromolecular composition or article, e.g. leaching out - A61F 2002/2817: {Bone stimulation by chemical reactions or by osteogenic or biological products for enhancing ossification, e.g. by bone morphogenetic or morphogenic proteins [BMP] or by transforming growth factors [TGF]} - A61F 2002/2835: {Bone graft implants for filling a bony defect or an endoprosthesis cavity, e.g. by synthetic material or biological material} - A61F 2002/30957: {using a positive or a negative model, e.g. moulds} - B29C 43/14: in several steps - B29C 2791/001: Shaping in several steps - B29C 2791/002: Making articles of definite length, i.e. discrete articles (B29C53/40 takes precedence) - B29C 2793/0072: combined with rearranging and joining the cut parts - B29C 2793/0081: before shaping - B29C 2793/009: after shaping - B29K 2071/00: Use of polyethers {, e.g. PEEK, i.e. polyether-etherketone or PEK, i.e. polyetherketone or derivatives thereof}, as moulding material - B29K 2101/12: Thermoplastic materials - B29K 2105/04: cellular or porous - B29K 2105/045: {with open cells} - B29K 2105/251: {Particles, powder or granules (expandable particles B29K2105/046)} - B29K 2995/0056: Biocompatible, e.g. biopolymers or bioelastomers - B29L 2031/7532: {Artificial members, protheses} - C08J 2201/0444: Salts - C08J 2201/0446: Elimination of NaCl only - C08J 2371/10: from phenols - C08J 2471/10: from phenols - B29C: SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING (making preforms B29B11/00; making laminated products by combining previously unconnected layers which become one product whose layers will remain together B32B37/00 - B32B41/00) - 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 (dental prosthetics A61C) - 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 (preservation of bodies or disinfecting characterised by the agents employed A01N; preserving, e.g. sterilising, food or foodstuffs A23; preparations for medical, dental or toiletry purposes A61K) - C08J: WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H (working, e.g. shaping, of plastics B29) - B29K: INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR {MOULDS, } REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS - B29L: INDEXING SCHEME ASSOCIATED WITH SUBCLASS B29C, RELATING TO PARTICULAR ARTICLES ## Abstract A method for forming a thermoplastic body having regions with varied material composition and/or porosity. Powder blends comprising a thermoplastic polymer, a sacrificial porogen and an inorganic reinforcement or filler are molded to form complementary parts with closely toleranced mating surfaces. The parts are formed discretely, assembled and compression molded to provide a unitary article that is free from discernible boundaries between the assembled parts. Each part in the assembly has differences in composition and/or porosity, and the assembly has accurate physical features throughout the sections of the formed article, without distortion and nonuniformities caused by variable compaction and densification rates in methods that involve compression molding powder blends in a single step. ## Claims ### Claim 1 A method for forming a unitary article, comprising the following steps: i. provide at least two powder blends, each of the at least two powder blends being selected from the group consisting of at least one polymer powder, at least one polymer powder with at least one porogen powder, at least one polymer powder with at least one inorganic particle powder, and at least one polymer powder with at least one porogen powder and at least one inorganic particle powder, such that the at least two powder blends differ from one another in terms of content of the polymer powder, content of the porogen powder, content of the inorganic particle powder, or a combination thereof; ii. dispense each of the at least two powder blends into at least one mold; iii. compact each of the at least two powder blends into two or more preforms; iv. machine each of the two or more preforms into two or more parts with complementary mating surfaces; v. assemble the two or more parts with complementary mating surfaces to form an article assembly; vi. compression mold the article assembly to form a unitary article; vii. optionally form additional features in the unitary article; and viii. leach porogen from the unitary article. ### Claim 2 (depends on 1) The method according to claim 1, wherein the unitary article is a biomedical implant. ### Claim 3 (depends on 1) The method according to claim 1, wherein the unitary article is free from discernible boundaries between portions of the unitary article derived from the two or more parts with complementary mating surfaces. ### Claim 4 (depends on 1) The method according to claim 1, wherein the unitary article is free of metals other than bioactive reinforcement particles. ### Claim 5 (depends on 1) The method according to claim 1, wherein step ii. includes dispensing the at least two powder blends into separate molds. ### Claim 6 (depends on 1) The method according to claim 1, wherein step ii. includes dispensing the at least the powder blends as dry powder layers into a single mold. ### Claim 7 (depends on 1) The method according to claim 1, wherein step iii. further includes compacting the at least two powder blends at a selected pressure. ### Claim 8 (depends on 1) The method according to claim 1, wherein step iii. includes compacting the at least two powder blends by compression molding at elevated temperature. ### Claim 9 (depends on 1) The method according to claim 1, wherein step iii. includes compacting the at least two powder blends by cold pressing. ### Claim 10 (depends on 1) The method according to claim 1, wherein the complementary mating surfaces of the two or more parts exhibit close tolerances for assembly. ### Claim 11 (depends on 1) The method according to claim 1, wherein the at least one polymer powder of each of the at least two powder blends is the same. ### Claim 12 (depends on 1) The method according to claim 1, wherein the at least one inorganic particle powder, when present in a powder blend of the at least two powder blends, is present in the range from about 1 to about 99 percent based on the total volume of the portion of the powder blend comprising the at least one polymer powder and the at least one inorganic particle powder, and wherein the at least one porogen powder, when present in a powder blend of the at least two powder blends, is present in the range from about 1 to about 99 percent based on the total volume of the powder blend comprising the at least one polymer powder and the at least one porogen powder. ### Claim 13 (depends on 1) The method according to claim 1, wherein compression molding in one or more of the steps v. and vii. includes applying compression at a specified pressure to prevent volumetric expansion during heating. ### Claim 14 (depends on 1) The method according to claim 1, wherein compression molding in one or more of the steps v. and vii. includes heating to the melting point of the at least one polymer powder and then cooling to a temperature just below the melting point of the at least one polymer powder, and applying pressure that is elevated over atmospheric to mold a preform of the two or more preforms or the article assembly into a monolithic body, the step of applying pressure occurring at any point in time after heating above the melting temperature of the at least one polymer powder and up to and through cooling to a temperature below the melting temperature but above the glass transition temperature of the at least one polymer powder. ### Claim 15 A method for forming a unitary article, comprising the following steps: i. assembling two or more parts with complementary mating surfaces to form an article assembly, at least one of the two or more parts with complementary mating surfaces including at least one porogen; ii. compression molding the article assembly to form a unitary article free from discernible boundaries between portions of the unitary article derived from the two or more parts with complementary mating surfaces; iii. optionally forming additional features in the unitary article; and iv. leaching the at least one porogen from the unitary article, wherein at least one of the two or more parts with complementary mating surfaces is formed by: dispensing a powder blend into at least one mold, the powder blend including: at least one polymer powder; the at least one porogen in powder form; and optionally, at least one inorganic particle powder; compacting the powder blend in the at least one mold to form at least one preform; and machining the at least one preform. ### Claim 16 (depends on 15) The method according to claim 15, wherein the unitary article is a biomedical implant. ### Claim 17 (depends on 15) The method according to claim 15, wherein the unitary article is free of metals other than bioactive reinforcement particles. ### Claim 18 A method for forming a unitary article, the method comprising: i. discretely forming at least two parts by either compression molding or cold pressing, each of the at least two parts being formed from at least two powder blends selected from the group consisting of at least one polymer powder, at least one polymer powder with at least one porogen powder, at least one polymer powder with at least one inorganic particle powder, and at least one polymer powder with at least one porogen powder and at least one inorganic particle powder; ii. machining each of the at least two parts to provide at least two interfitting machined parts, the at least two interfitting machined parts each comprising complementary mating surfaces; iii. assembling the at least two interfitting machined parts to form an assembly; and iv. compression molding the assembly to provide a unitary article that is free from discernible boundaries between portions of the unitary article derived from the at least two interfitting machined parts. ### Claim 19 (depends on 18) The method according to claim 18, wherein each of the at least two parts is formed either in separate molds, or each as a discrete layer in a single mold, and wherein when the at least two of the at least two parts are formed as discrete layers in the single mold, the step of machining to provide the at least two interfitting machined parts includes separating the discrete layers. ### Claim 20 (depends on 18) The method according to claim 18, wherein step i. includes: preparing at least three parts as the at least two parts from at least two different of the at least two powder blends; preparing the at least two parts from at least two different of the at least two powder blends wherein at least one of the at least two different of the at least two powder blends includes the at least one polymer powder and the at least one inorganic particle powder and does not include any of the at least one porogen powder, and another of the at least two different of the at least two powder blends includes the at least one polymer powder, the at least one porogen powder and the at least one inorganic particle powder; or preparing the at least two parts from at least two different of the at least two powder blends, wherein the at least two different of the at least two powder blends each includes the at least one polymer powder, the at least one porogen powder, and the at least one inorganic particle powder.