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WO1999056800A1 - Systeme de biomateriau composite poreux et de biopolymere - Google Patents

Systeme de biomateriau composite poreux et de biopolymere Download PDF

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Publication number
WO1999056800A1
WO1999056800A1 PCT/US1999/010004 US9910004W WO9956800A1 WO 1999056800 A1 WO1999056800 A1 WO 1999056800A1 US 9910004 W US9910004 W US 9910004W WO 9956800 A1 WO9956800 A1 WO 9956800A1
Authority
WO
WIPO (PCT)
Prior art keywords
biopolymer
biomaterial
bone
composite material
flowable
Prior art date
Application number
PCT/US1999/010004
Other languages
English (en)
Inventor
Jeffrey C. Felt
Original Assignee
Advanced Bio Surfaces, Inc.
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 Advanced Bio Surfaces, Inc. filed Critical Advanced Bio Surfaces, Inc.
Priority to AU40715/99A priority Critical patent/AU4071599A/en
Publication of WO1999056800A1 publication Critical patent/WO1999056800A1/fr

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Classifications

    • 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
    • A61F2/28—Bones
    • 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
    • A61F2/30721—Accessories
    • 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
    • A61F2/30721—Accessories
    • A61F2/30749—Fixation appliances for connecting prostheses to the body
    • 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
    • A61L27/40—Composite materials, i.e. containing one material dispersed in a matrix of the same or different material
    • A61L27/42—Composite materials, i.e. containing one material dispersed in a matrix of the same or different material having an inorganic matrix
    • A61L27/422—Composite materials, i.e. containing one material dispersed in a matrix of the same or different material having an inorganic matrix of carbon
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B17/00—Surgical instruments, devices or methods
    • A61B17/56—Surgical instruments or methods for treatment of bones or joints; Devices specially adapted therefor
    • A61B17/58—Surgical instruments or methods for treatment of bones or joints; Devices specially adapted therefor for osteosynthesis, e.g. bone plates, screws or setting implements
    • A61B17/68—Internal fixation devices, including fasteners and spinal fixators, even if a part thereof projects from the skin
    • A61B17/84—Fasteners therefor or fasteners being internal fixation devices
    • A61B17/86—Pins or screws or threaded wires; nuts therefor
    • A61B17/8645—Headless screws, e.g. ligament interference screws
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61C—DENTISTRY; APPARATUS OR METHODS FOR ORAL OR DENTAL HYGIENE
    • A61C8/00—Means to be fixed to the jaw-bone for consolidating natural teeth or for fixing dental prostheses thereon; Dental implants; Implanting tools
    • A61C8/0012—Means to be fixed to the jaw-bone for consolidating natural teeth or for fixing dental prostheses thereon; Dental implants; Implanting tools characterised by the material or composition, e.g. ceramics, surface layer, metal alloy
    • 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
    • A61F2/38—Joints for elbows or knees
    • A61F2/389—Tibial components
    • 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
    • A61F2002/30001—Additional features of subject-matter classified in A61F2/28, A61F2/30 and subgroups thereof
    • A61F2002/30316—The prosthesis having different structural features at different locations within the same prosthesis; Connections between prosthetic parts; Special structural features of bone or joint prostheses not otherwise provided for
    • A61F2002/30535—Special structural features of bone or joint prostheses not otherwise provided for
    • A61F2002/30581—Special structural features of bone or joint prostheses not otherwise provided for having a pocket filled with fluid, e.g. liquid
    • A61F2002/30583—Special structural features of bone or joint prostheses not otherwise provided for having a pocket filled with fluid, e.g. liquid filled with hardenable fluid, e.g. curable in-situ
    • 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
    • A61F2/30771—Special external or bone-contacting surface, e.g. coating for improving bone ingrowth applied in original prostheses, e.g. holes or grooves
    • A61F2002/3085—Special external or bone-contacting surface, e.g. coating for improving bone ingrowth applied in original prostheses, e.g. holes or grooves with a threaded, e.g. self-tapping, bone-engaging surface, e.g. external surface
    • A61F2002/30868—Square, rectangular or rhomboidal threads
    • 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
    • A61F2210/00—Particular material properties of prostheses classified in groups A61F2/00 - A61F2/26 or A61F2/82 or A61F9/00 or A61F11/00 or subgroups thereof
    • A61F2210/0085—Particular material properties of prostheses classified in groups A61F2/00 - A61F2/26 or A61F2/82 or A61F9/00 or A61F11/00 or subgroups thereof hardenable in situ, e.g. epoxy resins
    • 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

Definitions

  • the present invention relates to methods and apparatuses for resurfacing or repairing orthopedic joints. In another aspect the invention relates to cancellous bone substitutes.
  • such a system can be used to resurface the knee, e.g., by a method that involves the use of minimally invasive means to form one or more anchor points within the subchondral bone of the tibial surface, and thereafter delivering a flowable, curable biopolymer, adapted to be cured in situ in order to fill the anchor points and resurface the joint.
  • the anchor points can be of any suitable configuration, and can be prepared using a variety of techniques, e.g., by the use of arthroscopic drill bits.
  • pore sizes less than 10 microns prevent ingrowth of cells; pore sizes of 15-50 microns encourage fibrovascular ingrowth; pore sizes to 50-150 microns result in osteoid formation; and pore sizes of greater than 150 microns facilitate the ingrowth of mineralized bone.
  • Bone ingrowth into the voids of a porous material provides ideal skeletal fixation for the permanent implants used for the replacement of bone segments lost due to any number of reasons, or in total joint prostheses.
  • Biological compatibility, intimate contact with the surrounding bone, and adequate stability during the early period of bone ingrowth have been identified as important requirements, along with proper porosity.
  • the optimal porous material should have good crack resistance, particularly under impact, and a compliance comparable to that of bone.
  • the material should also make the manufacture of implants of precise dimensions easy, and permit the fabrication of either thick or thin coatings on load-bearing cores.
  • the implant be placed next to viable bone.
  • the presence of bone within the implant has become presumptive evidence of osteoconductive properties: that is, the ability of bone to grow into a porous structure when the structure is placed next to bone. Initially, the cells that interface the implant convert to bone, then the front of regenerated bone progresses into the implant. This process is known as osseointegration, meaning the achievement of direct contact between living bone and implant.
  • Figure 1 shows a biomaterial of the present invention in the form of a generally cylindrical dowel-pin device, having a slot adapted to be filled with biomaterial;
  • Figure 2 shows an alternative structure in which a dowel-pin device is provided with a circumferential groove and threads.
  • the present invention provides a surgical system for preparing a composite material in situ, the system comprising a unique combination of a flowable, curable biopolymer and a porous, implantable biomaterial.
  • the biomaterial is preferably fabricated to form an anchor material that is adapted (e.g., in terms of structure, porosity and chemical compatabihty) to permit it to be positioned within bone and to permit at least a portion of it to be filled and/or infiltrated with flowable biopolymer in order to provide a mechanical lock between the two.
  • the resulting cured composite is initially retained in position within the bone, largely by virtue of its mechanical properties, where the porosity of its biomaterial component serves to encourages new bone ingrowth over time.
  • Bone ingrowth serves to further stabilize the retention of the implant over extended use, and thereby improve its performance.
  • the mechanical lock between biopolymer and biomaterial can be formed in any suitable manner, e.g., by the infiltration of curing biopolymer into pores of the biomaterial itself, and/or by filling the biopolymer into grooves or other structures within the biomaterial.
  • the biopolymer Once in place within the biomaterial, the biopolymer is able to fully cure in order to retain and anchor the resultant composite material.
  • the composite material (and preferably the anchor component thereof) is adapted to encourage new bone ingrowth, in order to stabilize the retention of the implant over extended use and improve its performance.
  • the biopolymer comprises the components of a polyurethane and the porous anchor material comprises a reticulated open cell carbon foam infiltrated with tantalum by a process of chemical vapor deposition (CVD).
  • the composite is preferably positioned in temporary or permanent touching, or bonded, contact with bone.
  • the invention provides a method of preparing and using such a system, as well as kits and/or components adapted to perform such a method.
  • the invention provides a composite material comprising a biomaterial filled and/or infiltrated, at least in part, with a cured biopolymer and having bone ingrown into at least some of its pores, the composite being positioned within an orthopedic site, e.g., within or in apposition to a bone surface.
  • suitable anchor materials include calcium hydroxyapatite (HA), as well as nonmetallic materials adapted for use in porous form for implants, including the ceramics tricalcium phosphate (TCP), calcium aluminate, and alumina, carbon; various polymers, including polypropylene, polyethylene, and polyoxymethylene (delrin); and ceramic-reinforced or -coated polymers. Ceramics, while strong, are less preferred since they tend to be brittle and often fracture readily under loading. Polymers, in turn, while possessing good ductility, are also less preferred since they tend to be weak.
  • Metals, and metal-containing materials are particularly preferred since they tend to combine high strength and good ductility, making them attractive candidate materials for implants (and effectively the most suitable for load-bearing applications).
  • Many dental and orthopedic implants contain metal, and are useful in the present system, most often titanium or various alloys such as stainless steel or vitallium (cobalt-chromium-molybdenum). Ceramic-coated metals are also useful, e.g., HA or TCP on titanium. While conventional metallic biomaterials can be used (e.g. stainless steel, cobalt-based alloys), they are less preferred in that they do not easily lend themselves to fabrication into porous structures. Examples of other suitable materials are described, for instance, in Higgins et al., US Patent No.
  • the '932 patent describes a surgical technique for the delivery of bone graft material to a medullary canal and implantation of a prosthetic device includes placing bone graft material into an elongate hollow tube and arranging a plunger having an elongate rod portion into the hollow tube.
  • a carbon foam is infiltrated as a vapor in the process of chemical vapor deposition (CVD).
  • CVD chemical vapor deposition
  • the resulting lightweight, strong, porous structure mimicking the microstructure of natural cancellous bone, acts as a matrix for the incorporation of bone or reception of cells and tissue.
  • the pores of the matrix are preferably connected to one another to form continuous, uniform channels with no dead ends. This intricate network of interconnected pores provides optimal permeability and a high surface area to encourage cell and tissue ingrowth, vascularization, and deposition of new bone.
  • the result is a biomaterial composite that, when placed next to bone or tissue and infiltrated in part with flowable biopolmer, initially serves as a prosthesis and anchor, and then functions, at least in part, as a scaffold for regeneration of normal tissues.
  • the new biomaterial composite fulfills the need for an implant modality that has a precisely controllable shape and at the same time provides an optimal matrix for cell and bone ingrowth as well as biopolymer infiltration.
  • the physical and mechanical properties of the porous metal structure can be specifically tailored to the particular application at hand. While certain preferred porous materials are strong, and have an elasticity close to trabeculated bone, it is particular preferred that once placed within the bone, and following bone ingrowth, the resultant material have a modulus that approximates that of surrounding bone.
  • Presently preferred materials therefor exhibit a porosity (or portions that provide a plurality or continuum of porosities) in order to provide an optimal combination of such properties as polymer permeation and final modulus.
  • a particularly preferred porous biomaterial includes a plurality of portions of varying porosities, including for instance, an outermost portion adapted to positioned within or adjacent to corresponding cartilage) a pore size particularly conducive to polymer permeation, followed by a portion having a pore size adapted to enhance cortical bone (and to be positioned within or adjacent to subchondral bone); and finally, one or more pore sizes adapted to match the modulus of surrounding trabeculated bone, and to be positioned therein.
  • a porous structure that minimizes the presence of material (e.g., metal); a modulus transition between the material and bone that substantially covers the entire surface below the polymer in order to minimize side loading modulus mismatch; the ability to be permeated by a polymeric substance having any desired viscosity (e.g., between about 10,000 and about 200,000 poise); and the ability to create creates a continuous modulus transition between the polymer and the core material, by varying the pore size accordingly.
  • material e.g., metal
  • a modulus transition between the material and bone that substantially covers the entire surface below the polymer in order to minimize side loading modulus mismatch
  • the ability to be permeated by a polymeric substance having any desired viscosity e.g., between about 10,000 and about 200,000 poise
  • the ability to create creates a continuous modulus transition between the polymer and the core material by varying the pore size accordingly.
  • Tantalum is preferred as the material of choice based on its good mechanical properties, excellent corrosion resistance, and demonstrated biocompatibility.
  • Tantalum (atomic number 73, atomic weight 180.95, density 16.68 g/cm ⁇ ) is a transition element (periodic group VB), a highly refractory (melting point 2996° C), strong, ductile metal with excellent oxidation and corrosion resistance.
  • niobium which has similar chemical and mechanical properties to tantalum, may also be used as well as appropriate alloys of tantalum and niobium.
  • other metals such as niobium, hafnium and/or tungsten could be alloyed with the tantalum or hafnium and/or tungsten with niobium to change modulus and/or strength. Therefore, any reference to tantalum is not meant to be an exclusion of other metals.
  • tantalum pacemaker electrodes have exhibited excellent corrosion resistance both in vitro and in vivo. This inertness likely accounts for the good tissue compatibility of the base metal as well, whereas a noble metal such as gold, though considered corrosion-resistant, is not sufficiently biocompatible due to its catalytic surface.
  • Tantalum does not inhibit cell growth and indeed becomes tightly enveloped by new osseous tissue soon after implantation, whereas dental gold and cobalt-based alloys can inhibit cell growth and cause bone resorption.
  • tantalum osseous ingrowth has been demonstrated by others right up to and into implants.
  • Complete, strong, long-term osseointegration has been demonstrated with tantalum implants in both dental and orthopedic applications, under both unloaded and heavily loaded conditions, for implantation periods as long as eight to twelve years.
  • tantalum has an elastic modulus close to that of bone, much closer than any of the other high- strength metals and alloys commonly used for implants; this too may well contribute to the favorable reaction with bone. With its greater ductility, excellent corrosion resistance, good workability, and demonstrated biocompatibility, tantalum is a preferred material for use in a system of the present invention, combined with one or more biopolymers as described herein.
  • a system of the present invention is particularly well suited for use in delivering an anchor material and a curable biomaterial (i.e., biopolymer) composition by minimally invasive techniques to a tissue site within the body.
  • a curable biomaterial i.e., biopolymer
  • repair will refer to the use of a composition to augment, replace or provide some or all of the structure or function of natural tissue in vivo, for instance, to provide an implant such as a catheter, or to repair (e.g., reconstruct or replace) natural tissue such as cartilage, e.g., fibrocartilage or hyaline cartilage present in a diarthroidal or amphiarthroidal joint. Repair can take any suitable form, e.g., from patching the tissue to replacing it in its entirety, preferably in a manner that reconstructs its natural or other desired dimensions;
  • curable and inflections thereof will refer to any chemical, physical, and/or mechanical transformation that allows a composition to progress from a form (e.g., flowable form) that allows it to be delivered to the joint site, into a more permanent (e.g., cured) form for final use in vivo.
  • curable can refer to uncured composition, having the potential to be cured in vivo (as by catalysis or the application of a suitable energy source), as well as to a composition in the process of curing (e.g., a composition formed at the time of delivery by the concurrent mixing of a plurality of composition components).
  • the cure of a composition can generally be considered to include three stages, including (a) the onset of gelation, (b) a period in which gelation occurs and the composition becomes sufficiently tack- free to permit shaping, and (c) complete cure to the point where the composition has been finally shaped for its intended use; and
  • minimally invasive refers to surgical techniques, such as microsurgical or endoscopic or arthroscopic surgical techniques, that can be accomplished with minimal disruption of the pertinent musculature, for instance, without the need for open access to the tissue injury site or through minimal incisions (e.g., incisions of less than about 4 cm and preferably less than about 2 cm). Such techniques are typically accomplished by the use of visualization such as fiberoptic or microscopic visualization, and provide a post-operative recovery time that is substantially less than the recovery time that accompanies the corresponding open surgical approach.
  • Biopolymer Biopolymers suitable for use in the present invention can be provided in any suitable form, e.g., as two or more individual components.
  • Some or all of these components can be provided either within or upon the body portion itself (e.g., in attachable syringe cartridges) or remote therefrom (e.g., as canisters attached or attachable by tubing to the body portion itself).
  • the onset of flow of the components, and in turn their mixing, is preferably controlled by the user, e.g., by actuating a mechanical delivery means or by making electrical contact.
  • the invention provides for a plurality of different biopolymers, the delivery of any or all being connectable and controllable by the user.
  • the user can control the types or relative amounts of various components being delivered, e.g., to provide for mixed biopolymer compositions having different desired (cured or curing) properties.
  • the components for a two-component biopolymer source can be predetermined to be mixed in any suitable order and ratio, e.g., in a 1 : 1 (volume to volume) ratio, or between about 1 : 10 or 10: 1.
  • biopolymer source will refer to the actual component containment vessels (e.g., canisters or syringes) themselves, as well as associated supports, tubing, controls and the like, for use in attaching the containment vessels to the body portion and delivering their contents to the inlet end of the mixing path.
  • a device of this invention can be manufactured, used and sold either with the biopolymer source in attached or attachable form (e.g., in the form of the syringes described herein), or without the biopolymer source (e.g., in the form of the gun assembly described herein).
  • the user will typically provide a separate single-use or stock supply of the biopolymer, which will be attached to the device at or near the time of use.
  • the biopolymer source can be flowably attached to the device at the time of use and in a sterile manner.
  • a system of the invention preferably includes a biopolymer composition having two or more parts, where the parts can be combined at the time of use in order to initiate cure.
  • a preferred biopolymer composition for use in a device of this invention is a curable polyurethane composition comprising a plurality of parts capable of being sterilized, stably stored, and mixed at the time of use in order to provide a flowable composition and initiate cure.
  • the parts include: (1) a quasi-prepolymer component comprising the reaction product of one or more polyether polyols, one or more isocyanates, and one or more reactive hydrophobic additives, and (2) a curative component comprising one or more polyether polyols, one or more chain extenders, one or more catalysts, and optionally, other ingredients such as an antioxidant and dye.
  • the composition is sufficiently flowable to permit it to be delivered to the body using a device as described herein, and fully cured within the body under physiologically acceptable conditions.
  • the component parts are themselves flowable, or can be rendered flowable (e.g., by heating), in order to facilitate their mixing and use.
  • the polyether component is present at a concentration of between about 2% and about 10 %, and preferably between about 4% and about 8% by weight, based on the weight of the composition, and is selected from the group consisting of linear or branched polyols with polyether backbones of polyoxyethylene, polyoxypropylene, and polytetramethylene oxide (polyoxytetramethylene), and copolymers thereof.
  • a particularly preferred polyol is polytetramethylene oxide, preferably of relatively low molecular weights in the range of 250 daltons to 2900 daltons, and combinations thereof.
  • the isocyanate is present in excess in the prepolymer component, e.g., at a concentration of between about 30% and about 50%, and preferably between about 35% and about 45%, by weight.
  • the isocyanate is preferably an aromatic (poly)isocyanate selected from the group consisting of 2,2'- , 2,4'- , and 4,4'-diphenylmethanediisocyanate (MDI), and combinations thereof.
  • the reactive polymer additive itself is present at a concentration of between about 1% and about 50% by weight, and is selected from the group consisting of hydroxyl- or amine-terminated compounds selected from the group consisting of poybutadiene, polyisoprene, polyisobutylene, silicones, polyethylenepropylenediene, copolymers of butadiene with acryolnitrile, copolymers of butadiene with styrene, copolymers of isoprene with acrylonitrile, copolymers of isoprene with styrene, and mixtures of the above.
  • the additive comprises hydroxyl-terminated polybutadiene, present at a concentration of between about 5% and about 30%, by weight, and preferably between about 5% and about 20% by weight.
  • the polyether polyol of the curative component is as described above with regard to the prepolymer and is present at a final concentration of between about 20% and 60%, and preferably between about 30%) and about 45%, by weight.
  • the chain extender comprises a combination of linear (e.g., cyclohexane dimethanol (“CHDM”)) and branched (e.g, trimethyloyl propane (“TMP”) chain extenders, with the former being present at a final concentration of between about 1% and 20 % (and preferably between about 5% and about 15%), and the latter being present at a final concentration of between about 1% and about 20%, and preferably between about 1% and about 10%, by weight of the final composition.
  • CHDM cyclohexane dimethanol
  • TMP trimethyloyl propane
  • a polymer system of this invention is provided as a plurality of component parts and employs one or more catalysts.
  • the component parts, including catalyst can be mixed to initiate cure, and then delivered, set and fully cured under conditions (e.g., time and exotherm) sufficient for its desired purpose.
  • the resultant composition Upon the completion of cure, the resultant composition provides an optimal combination of properties for use in repairing or replacing injured or damaged tissue.
  • a suitable composition provides a bulk exotherm (within samples sizes suitable for in vivo use) of between about 100 degrees C and about 140 degrees C, and preferably between about 110 degrees C and about 130 degrees C, and a surface exotherm of between about 50 degrees C and about 80 degrees C, and preferably between about 60 degrees C and about 70 degrees C.
  • a polymer system of the present invention preferably contains one or more, and more preferably two or more, biocompatible catalysts that can assist in controlling the curing process, including the following periods: (1) the induction period, (2) the setting period, and finally, (3) the final cure of the biopolymer. Together these three periods, including their absolute and relative lengths, and the rate of acceleration or cure within each period, determine the cure kinetics or profile.
  • the word "induction”, and inflections thereof, when used in this respect refers to the time period between mixing or activation of one or more polymer components (under conditions suitable to begin the curing process), and the onset of gelation. In a method of the present invention, this period generally corresponds with the delivery of the biopolymer to the site of ultimate use.
  • the induction period is characterized by infinitesimal or limited increase in viscosity of reacting mixture and relatively flat exotherm profile.
  • a biopolymer of this invention is simultaneously mixed just prior to actual delivery into the joint site, providing the surgeon with sufficient time to add and position material (e.g., into anchor points) before gelation causes the material to become less easily workable. Thereafter, the surgeon can leave the material in place as it sets, e.g., for on the order of three to twenty minutes, before placing instruments back into the site to finish sculpting the implant, or performing other desired steps such as positioning the femoral condyles to shape the implant.
  • set time (or gel time), as used herein, is determined from the initial mixing of components, and refers to the time needed for a mixed and delivered system to set to the point where it can be shaped. This period is characterized by a rapid rise in the slope of the reaction exotherm at the end of the period. By the end of this period, the surface of the gelled biopolymer is preferably tack free and will allow shaping, e.g., by positioning of the condyles.
  • cure time is determined from the initial mixing, and refers to the total time needed to mix, shape and fully cure the biopolymer to the desired extent under the conditions used.
  • Preferred polymer systems of this invention preferably provide an induction period that ends within about thirty seconds to two minutes following mixing of the components, followed by a set time of about 3 to about 15 minutes following mixing.
  • the polymer system preferably exhibits an exotherm compatible for its intended use, e.g., preferably an exotherm of less than about 70 degrees C to about 90 degrees C, and more preferably less than about 80 degrees C.
  • an exotherm compatible for its intended use e.g., preferably an exotherm of less than about 70 degrees C to about 90 degrees C, and more preferably less than about 80 degrees C.
  • Catalysts suitable for use in compositions of the present invention provide an optimal combination of such properties as set time, cure time, and in turn, viscosity (and flowability) of the curing polymer system.
  • the selection of catalyst and other ingredients provides a cure profile that exhibits both synergistic and "delayed action” kinetics, in which induction of cure begins immediately upon mixing the polymer components, and is relatively “flat” during the induction period, without significant increase of viscosity of reaction mixture.
  • This period permits delivery of the "flowable" polymer to the tissue injury site, and is followed by a setting period characterized by variable increase in slope (in a plot of temperature vs. time) that is designed to quickly drive the curing process to completion, and in turn, to quickly provide a set polymer that is sufficiently strong and tack-free to permit final shaping.
  • the composition of the present invention can be delivered to a site within the body, and there fill or infiltrate at least a portion (e.g, groove or surface) of a porous biomaterial, e.g., one delivered prior to, with, after the delivery of the polymeric composition itself.
  • the biopolymer can then be cured, preferably using minimally invasive means, in order to repair (e.g., reconstruct or resurface) tissue such as cartilage, and particularly cartilage associated with diarthroidal and amphiarthroidal joints.
  • the composition can be delivered and cured within an implanted mold device.
  • a device as described herein can also be used to deliver biopolymer to a site within the body, e.g., to a mold or a site of damaged or diseased cartilage, to be cured in situ in order to provide an implant or repair the cartilage without undue surgical trauma.
  • the invention also provides a kit comprising both a porous biomaterial as described herein in combination with a plurality of sterile, flowable parts capable of being mixed at the time of use in order to provide a flowable composition and to initiate cure, the parts including: (1) a quasi-prepolymer component comprising the reaction product of one or more polyether polyols, one or more isocyanates, and one or more reactive hydrophobic additives, and (2) a curative component comprising one or more polyether polyols, one or more chain extenders, and one or more catalysts.
  • the device can be used to mixed the quasi-prepolymer component and curative component, in order to deliver the mixture to a tissue site using minimally invasive means.
  • two or more biopolymer compositions can be delivered, e.g., sequentially, for instance to provide a biphasic or a heterogeneous cured material having varying properties, or to facilitate the ability of the biopolymer to infiltrate the pores of the biomaterial.
  • porous biomaterial and biopolymer source can be manufactured, sterilized, and sold alone, or sold together in a kit, e.g., with the biomaterial being provided in the form of a screw or pin, and the biopolymer source adapted to be mixed at the time of use in order to initiate infiltration into the biomaterial and cure.
  • a kit e.g., with the biomaterial being provided in the form of a screw or pin, and the biopolymer source adapted to be mixed at the time of use in order to initiate infiltration into the biomaterial and cure.
  • Cancellous, or spongy, bone is composed of a porous space-frame structure formed of open spaces defined by interconnected trabeculae, oriented along lines of principal stresses. At the microstructural level, the trabeculae are composed of layers of lamellar bone. Cancellous bone has anisotropic mechanical properties, i.e. different structural behavior along different orientations. Along the axis of the major channels, cancellous bone exhibits elastic behavior with sudden brittle failure at ultimate load in tension. When loaded with a tensile force whose line of action is skewed with respect to the channel axis of the bone, the stress-strain curve is parabolic with plastic deformation and greater energy absorption.
  • the porous material can be provided in any suitable form and having any suitable dimensions, e.g., in the form of beads, sheets, mesh, or formed objects such as a tapered or straight (and solid or hollow), shank, screw, bolt, nail, peg or dowel- pin that is delivered and secured earlier, and in the course of the same surgical procedure.
  • the material is preferably adapted to be delivered to the site of repair and there positioned or anchored in permanent or temporary contact with bone or other appropriate bodily tissues, in a manner that permits the material to be permeated by polymer and, over time permit the ingrowth of tissue (e.g., bone).
  • the biomaterial in which the biomaterial is intended to fill one or more portions of the biomaterial, can be provided with one or more grooves, slits, or apertures of a suitable number, orientation and dimensions for their intended use.
  • one or more of the same feature(s) that facilitate the initial placement of the porous biomaterial e.g., screw slots
  • An anchor material of the present invention can include portions or parts that vary considerably in terms of porosity, including some portions (e.g., non-bone contacting portions) that are not porous at all, particularly when grooves or other means are used to provide an initial mechanical or chemical lock between biopolymer and biomaterial.
  • the word "porous”, and inflections thereof, as used to describe the biomaterial of the present invention will generally refer to an anchor material having at least one surface adapted to be positioned within bone in order to encourage bone ingrowth.
  • FIG. 1 shows a generally cylindrical, flat-headed biomaterial (10) having a slot (12) positioned centrally and perpendicular to the axis of the biomaterial, along the exposed head surface.
  • the biomaterial is shown positioned within an anchor point drilled into the subchondral bone of the tibial surface of the knee joint.
  • the biopolymer Upon filling the area with biopolymer (not shown) the biopolymer is able to fill the anchor point, as well as the groove, and including the tibial surface itself, in order to provide a permanent replacement articulating surface. Over time, bone is encouraged to grow into the portion of the biomaterial, thereby improving and ensuring the stability of the overall implant.
  • Figure 2 shows a related embodiment, also within an anchor point in the knee, in which the biomaterial (20) provides a circumferential groove (22) adapted to positioned within the and filled by biopolymer.
  • the lower portion of the biomaterial provides screw threads (24) that facilitate and secure its placement within the bone.
  • an optimal balance is preferably achieved between the properties of the biopolymer itself (e.g., cure rate, viscosity) and those of the biomaterial (e.g., pore size, distribution and type (e.g., open, closed, interconnected)) and their interaction (e.g., relative hydrophobility/hydrophilicity, heat exchange conditions, hydraulic resistance, contact angle, capillary effects).
  • properties of the biopolymer itself e.g., cure rate, viscosity
  • those of the biomaterial e.g., pore size, distribution and type (e.g., open, closed, interconnected)
  • their interaction e.g., relative hydrophobility/hydrophilicity, heat exchange conditions, hydraulic resistance, contact angle, capillary effects.
  • While the process itself can be complex, it may include an initial, and temporary, drop in viscosity due to the temperature increase (exotherm), followed by an increase in viscosity associated with the polymerization process itself.
  • the cure kinetics can be affected by the catalyst level and type, temperature, conditions of heat exchange (e.g., size and shape of the biomaterial and/or its pores).
  • Other means can be employed to facilitate infiltration, for instance, the use of coatings on the biomaterial to enhance its wettability to biopolymer, or the use of temporary extra pressure in the course of biopolymer delivery.
  • the presence of body fluids in the surgical area, including in the pores themselves, can affect infiltration and cure characteristics and final properties of the cured composite material.
  • the pores can be formed at the time of forming the support material itself, or thereafter, for instance by the use of laser technology to create micro-pores in a preformed material.
  • One company for instance (Surface Technologies, Israel), has developed a laser surface texturing system to improve the performance of lubricated mechanical components. The system creates evenly distributed micro-pores on the mating surface. The micro-pores generate a hydrodynamic effect which significantly improves performance and durability.
  • the system software includes a simulation model that enables the user to rapidly and accurately determine the optimal texturing settings for a given application, including the optimum pore diameter, depth, and distribution for any application.
  • biomaterials for use as substitutes for cancellous bone provide an optimal combination os such properties as elastic deformation and load distribution.
  • the biomaterial will preferably not not produce load concentrations, particularly if placed close to the underlying surface of articular cartilage, which might increase the local stresses on the articular surface and lead to wear and damage of the surface.
  • Cancellous bone demonstrates remodeling behavior according to Wolffs Law: that is, with the form being given, bone adapts to the loads applied to it. The converse is also true, and equally important: where loads are not applied, bone tends to resorb. An implant, then, must distribute stresses throughout its structure, the ingrowing bone, and the surrounding bone in order to avoid bone resorption and weakening caused by stress shielding.
  • cancellous bone The density of cancellous bone is 0.7 g/cm ⁇ ; its tensile modulus 0.2-0.5 GPa; tensile strength 10-12 MPa; and strain to failure 5-7%.
  • cancellous bone is -A as dense (indicating its porous nature); 1/10-1/20 as stiff; and five times as ductile.
  • the mechanical properties of the two types though, actually represent a continuum, reflecting the behavior of a relatively uniform material (bone) modified by differences in density and structure.
  • osseous implants should ideally reside in the bone without interfering with bone remineralization, the natural process by which the body replenishes bone.
  • the implant should be able to be precisely shaped and placed for optimal interface and performance.
  • non-resorption would be a beneficial quality for implants used in load-bearing applications, and/or those in which complete bone ingrowth is not possible.
  • the porous biomaterial is complete with respect to its interconnectivity, because constrictions between pores and isolated, deadend pockets can limit vascular support to ingrowing tissues; ischemia of the ingrowing bone cells results in failure of the implant. Incomplete vascularization or a reduction in the neovascularity also makes an implant vulnerable to bacterial colonization. Implants lacking completely interconnected porosity can also result in aberrant mineralization, stress shielding, low fatigue strength, and/or bulk displacement.
  • a preferred, open cell metal, structure of the present invention offers highly interconnected, three-dimensional porosity that is uniform and consistent, a structure exceptionally similar to that of natural cancellous bone.
  • porous metallic implant materials whose "porosity" is artificially produced via some form of surface treatment that does not result in a truly complete, open porosity.
  • these methods include macroscopic porous coatings (e.g. metal microspheres or wires sintered or otherwise attached to a bulk surface); microscopic surface porosity (e.g. metal powder particles flame- or plasma-sprayed onto a bulk surface); and controlled surface undulations machined into a bulk surface.
  • porous ceramic materials do offer full porosity (e.g. the replamineform process for hydroxyapatite), they are presently less preferred than the metals as discussed previously.
  • the open cell metal structure is osteoconductive, like other porous implants. Also, it is entirely biocompatible, based on the demonstrated biocompatibility of tantalum.
  • Allowing full mineralization is another preferred property of the present biomaterial.
  • the highly organized process of bone formation is a complex process and is not fully understood. There are, however, certain prerequisites for mineralization such as adequate pore size, presumably larger than 150 microns with interconnect size in the range of 75 microns.
  • a pore diameter of 200 microns corresponds to the average diameter of an osteon in human bone, while a pore diameter of 500 microns corresponds to remodeled cancellous bone.
  • the open cell metal structures of the present invention can be fabricated to virtually any desired porosity and pore size, and can thus be matched perfectly with the surrounding natural bone in order to provide an optimal matrix for ingrowth and mineralization. Such close matching and flexibility are generally not available with other porous implant materials.
  • An implant then, must distribute stresses throughout its structure, the ingrowing bone, and the surrounding bone in order to avoid bone resorption and weakening caused by stress shielding. Because metals are stronger than natural bone, this would seem to be a concern with a metallic implant in that the implant would itself focus and bear directly the majority of local loads and stresses that would ordinarily be placed on the bone, thus depriving both the existing and new bone of those forces which, in effect, help keep it at optimal strength.
  • the unique structure and properties of the open cell metal structures of the present invention avoid this drawback altogether.
  • the deposited thin films operate as an array within the porous metal body, contributing their exceptional mechanical properties to the structure at large.
  • One result of this effect is that imposed loads are distributed throughout the body.
  • stresses are distributed into both the ingrowing new bone and the surrounding existing bone as well, thereby providing both the old and new bone with the normal, healthy forces they require.
  • an implant can be designed to distribute stresses in a given direction(s), depending on the needs of the specific application at hand.
  • the bonding of regenerated bone to the implant also helps to transfer stresses directly to the bone in and around the implant; this sharing of biofunction is a consequence of the composite nature of the implant/bone structure.
  • the advantage of these metal structures over other porous implant materials is especially strong in this area. Ceramics lack sufficient mechanical properties to begin with, and no current implant material, either ceramic or metallic, possesses the unique properties of the metal structure as described here.
  • useful lightweight refractory structures are made by the chemical vapor deposition (CVD) of a small amount of metallic material such as tantalum or niobium (or combination of these materials with other materials to form alloys) into a reticulated (porous) vitreous carbon foam.
  • the density of the resultant body is purposely maintained at substantially below full density, resulting in a structure with extremely favorable properties.
  • the basic approach involves the use of a low-density carbon foam, which is infiltrated with the desired material by CVD to provide uniform thin films on all ligaments. These thin films provide exceptional strength and stiffness to the ligaments, with the expenditure of very little weight. Thin CVD films can provide much higher mechanical properties than can bulk materials.
  • the open cell metal biomaterial structures within a system of the present invention are preferably fabricated using the tantalum metal film and carbon substrate combination, with the film deposited by CVD, to form a structure which mimics bone closely in having open spaces interconnected by ligaments.
  • CVD chemical vapor deposition
  • open cell metal structure when employed in a system of the present invention, is that it is readily shapeable to nearly any configuration, simple or complex, simply by shaping the raw carbon substrate prior to metal infiltration. This facilitates exact contouring of the implant for the specific application and location; precise placement is enhanced and bulk displacement is prevented. Additionally, it appears that any final shaping/trimming needed at surgery can be accomplished on the final device using conventional dental or orthopedic equipment available at the time of surgery.
  • an implant can be designed allowing for motionlessness along all the interfaces necessary for a stable anchorage, thereby excluding (to the greatest extent possible) all outside influences on the remodeling process and allowing the local stress/strain field to control.
  • the metal foam device stays where it is placed without retention aids, and in turn serves to anchor and/or support the cured biopolymer, a reflection of precise contouring and the rapid ingrowth of fibrovascular tissue to prevent dislodgement.
  • the binding between bone and implant, and in turn between implant and biopolymer stabilizes the implant and prevents loosening.
  • These implants thus will not need to be held in place by other means (e.g. sutures or cement); rather, the growth of a natural bone-to-bone seal is encouraged by the nature of the implant itself. Tissue ingrowth would not be a contributing factor to device retention for a period following implantation, however, until a substantial amount of ingrowth had occurred.
  • An open cell metal structure for bone implants for use within a system of this invention, provides an optimal combination of such properties as compatabihty with the biopolymer, weight, density, strength, biocompatibility, porosity (e.g., high interconnected, uniform, three-dimensional porosity with high void fraction), structure (e.g., similar to natural cancellous bone), osteoconductivity, resorbability, the ability to be fabricated to virtually any desired porosity/pore size, mechanical properties, the ability of imposed loads to be distributed throughout the structure and into both the ingrowing new bone and the surrounding existing bone as well, the ability to avoid stress shielding; and the ability to be shaped to most desired configurations.
  • porosity e.g., high interconnected, uniform, three-dimensional porosity with high void fraction
  • structure e.g., similar to natural cancellous bone
  • osteoconductivity e.g., similar to natural cancellous bone
  • resorbability e.g., osteoconductivity, resorb
  • a system of the present invention will be described with reference to a preferred procedure for resurfacing the tibial plateau of the knee, in a manner that provides improved anchoring of the resultant implant by virtue of the use and presence of biomaterial anchor screws as described herein.
  • a trocar create two arthroscopic portals antermedial and anterolateral.
  • a third optional portal for irrigation of the joint supe ⁇ atellar may be created.
  • proximal medial tibia Place one pin just proximal to the origin area of the medial collateral ligament at distal femur and the other pin the area of the distal insertion site of the ligament (proximal medial tibia). If needed a small outside- in capsulotomy/MCL release may be carried out through a small stab wound medially. With the scope in the joint, the surgeon should be able to reach all areas of the medial tibial plateau, including the posterior medial meniscus when the external distractor is deployed and the plateau can be placed horizontal to the floor. The medial tibial plateau is arthroscopically accessed and prepared so as to remove all of the damaged cartilage on the weight-bearing surface of the medial tibial plateau.
  • the anterior edge of the cavity should be located at the level of the initial upslope of the tibial spine, extend mesial to the base of the tibial spine, lateral and posterior to the edge of the tibial plateau. If necessary, the medial meniscus may be debrided back to a stable rim. No lateral meniscal debridement or chondroplasty in the lateral or patellofemoral compartment should be done. Limited synovectomy in the medial compartment should only be done to improve visualization. Remove any fibrillated cartilage and smooth or feather cobblestone and ridged areas on the medial femoral condyle. Drill at least three (3) anchoring holes to a depth of 5 mm in the subchondral bone.
  • the anchor holes can be created in an inverted cone or gourd-shaped geometry to allow for a mechanical lock of the polymer with the subchondral bone once the polymer solidifies. Flex and extend the knee to flush particles from the posterior pouch, superpatellar fossa and posterior fossa. Suction out all areas of the joint with the arthroscope and dry the implant site.
  • the components of the biopolymer delivery apparatus including the delivery unit (including the delivery conduit, disc-like mixing path, and shunt tube or reservoir with valve control), body portion, and pre-heated dual barrel biopolymer cartridge from their packaging and place on the sterile field.
  • a conventional straight static mixer can be included and used as well, in a preliminary fashion, to facilitate the removal of any air bubbles that may exist in the biopolymer components.
  • the patient can be discharged the same day, non weight-bearing locked in extension in brace, and can resume full weight-bearing in 24 hours with brace removed.
  • the patient is recommended to be treated by a physical therapist with range of motion and strengthening exercises for approximately 8 weeks.
  • the present invention has been described with respect various preferred embodiments, which, together with other conditions and details should not be construed to unduly limit this invention.

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Abstract

L'invention concerne un système chirurgical qui comprend un biopolymère durcissable fluide et un biomatériau d'ancrage implantable poreux. Le matériau d'ancrage est conçu (p. ex. du point de vue de la porosité et de la compatibilité chimique) pour permettre au biopolymère fluide d'infiltrer une partie ou la totalité des pores du matériau et d'y durcir afin de retenir et ancrer le matériau composite obtenu. Le matériau composite peut être conçu pour activer une interposition d'os nouveau, afin de stabiliser la rétention de l'implant sur une longue période d'utilisation. Dans un mode de réalisation préféré, le biopolymère renferme les constituants d'un polyuréthanne et le matériau d'ancrage poreux renferme une mousse de carbone réticulée à alvéoles ouverts infiltrée par du tantale au moyen d'un procédé de dépôt chimique en phase vapeur (CVD).
PCT/US1999/010004 1998-05-07 1999-05-07 Systeme de biomateriau composite poreux et de biopolymere WO1999056800A1 (fr)

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Cited By (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6626945B2 (en) 2000-03-14 2003-09-30 Chondrosite, Llc Cartilage repair plug
EP1474071A2 (fr) * 2002-01-22 2004-11-10 Advanced Bio Surfaces, Inc. Systeme et procede d'arthroplastie avec interposition
WO2005009499A1 (fr) * 2003-07-15 2005-02-03 Kensey Nash Corporation Plaque de fixation souple pour osteosynthese
US7001431B2 (en) 1994-05-06 2006-02-21 Disc Dynamics, Inc. Intervertebral disc prosthesis
WO2007003513A1 (fr) * 2005-07-01 2007-01-11 Cinvention Ag Procede de fabrication de materiaux composites poreux reticules
WO2008122594A2 (fr) * 2007-04-05 2008-10-16 Cinvention Ag Implant thérapeutique partiellement biodégradable pour la réparation de l'os et du cartilage
WO2009152433A1 (fr) * 2008-06-13 2009-12-17 Zimmer, Inc. Élément de remplissage de cavité osseuse
US7906132B2 (en) 2002-09-17 2011-03-15 Biocer-Entwickslung GmbH Anti-infectious, biocompatible titanium coating for implants, and method for the production thereof
US8734514B2 (en) 2011-06-16 2014-05-27 Zimmer, Inc. Micro-alloyed porous metal having optimized chemical composition and method of manufacturing the same
US8956683B2 (en) 2011-06-16 2015-02-17 Zimmer, Inc. Chemical vapor infiltration apparatus and process
US9492291B2 (en) 2005-08-15 2016-11-15 Kunovus Pty Ltd. Systems, methods and apparatuses for formation and insertion of tissue prosthesis
US9510953B2 (en) 2012-03-16 2016-12-06 Vertebral Technologies, Inc. Modular segmented disc nucleus implant
US9737414B2 (en) 2006-11-21 2017-08-22 Vertebral Technologies, Inc. Methods and apparatus for minimally invasive modular interbody fusion devices
DE102018113809A1 (de) * 2018-06-11 2019-12-12 Christoph Karl Gelenkimplantat zur Gewebeneubildung am Gelenk

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US11331191B2 (en) 2015-08-12 2022-05-17 Howmedica Osteonics Corp. Bioactive soft tissue implant and methods of manufacture and use thereof

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5282861A (en) * 1992-03-11 1994-02-01 Ultramet Open cell tantalum structures for cancellous bone implants and cell and tissue receptors
US5556429A (en) * 1994-05-06 1996-09-17 Advanced Bio Surfaces, Inc. Joint resurfacing system

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5282861A (en) * 1992-03-11 1994-02-01 Ultramet Open cell tantalum structures for cancellous bone implants and cell and tissue receptors
US5556429A (en) * 1994-05-06 1996-09-17 Advanced Bio Surfaces, Inc. Joint resurfacing system

Cited By (26)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7001431B2 (en) 1994-05-06 2006-02-21 Disc Dynamics, Inc. Intervertebral disc prosthesis
US7077865B2 (en) 1994-05-06 2006-07-18 Disc Dynamics, Inc. Method of making an intervertebral disc prosthesis
US6852125B2 (en) 2000-03-14 2005-02-08 Chondrosite, Inc. Cartilage repair plug
US6626945B2 (en) 2000-03-14 2003-09-30 Chondrosite, Llc Cartilage repair plug
EP1474071A2 (fr) * 2002-01-22 2004-11-10 Advanced Bio Surfaces, Inc. Systeme et procede d'arthroplastie avec interposition
EP1474071A4 (fr) * 2002-01-22 2007-08-22 Advanced Bio Surfaces Inc Systeme et procede d'arthroplastie avec interposition
US7906132B2 (en) 2002-09-17 2011-03-15 Biocer-Entwickslung GmbH Anti-infectious, biocompatible titanium coating for implants, and method for the production thereof
WO2005009499A1 (fr) * 2003-07-15 2005-02-03 Kensey Nash Corporation Plaque de fixation souple pour osteosynthese
US8679163B2 (en) 2003-07-15 2014-03-25 Kensey Nash Corporation Compliant osteosynthesis fixation plate
US8679164B2 (en) 2003-07-15 2014-03-25 Kensey Nash Corporation Compliant osteosynthesis fixation plate
US7931695B2 (en) 2003-07-15 2011-04-26 Kensey Nash Corporation Compliant osteosynthesis fixation plate
WO2007003513A1 (fr) * 2005-07-01 2007-01-11 Cinvention Ag Procede de fabrication de materiaux composites poreux reticules
US9492291B2 (en) 2005-08-15 2016-11-15 Kunovus Pty Ltd. Systems, methods and apparatuses for formation and insertion of tissue prosthesis
US11491023B2 (en) 2006-11-21 2022-11-08 Next Orthosurgical, Inc. Methods and apparatus for minimally invasive modular interbody fusion devices
US10195048B2 (en) 2006-11-21 2019-02-05 Vertebral Technologies, Inc. Methods and apparatus for minimally invasive modular interbody fusion devices
US9737414B2 (en) 2006-11-21 2017-08-22 Vertebral Technologies, Inc. Methods and apparatus for minimally invasive modular interbody fusion devices
WO2008122594A3 (fr) * 2007-04-05 2009-07-30 Cinv Ag Implant thérapeutique partiellement biodégradable pour la réparation de l'os et du cartilage
WO2008122594A2 (fr) * 2007-04-05 2008-10-16 Cinvention Ag Implant thérapeutique partiellement biodégradable pour la réparation de l'os et du cartilage
WO2009152433A1 (fr) * 2008-06-13 2009-12-17 Zimmer, Inc. Élément de remplissage de cavité osseuse
US8734514B2 (en) 2011-06-16 2014-05-27 Zimmer, Inc. Micro-alloyed porous metal having optimized chemical composition and method of manufacturing the same
US9398953B2 (en) 2011-06-16 2016-07-26 Zimmer, Inc. Micro-alloyed porous metal having optimized chemical composition and method of manufacturing the same
US9277998B2 (en) 2011-06-16 2016-03-08 Zimmer, Inc. Chemical vapor infiltration apparatus and process
US8956683B2 (en) 2011-06-16 2015-02-17 Zimmer, Inc. Chemical vapor infiltration apparatus and process
US9510953B2 (en) 2012-03-16 2016-12-06 Vertebral Technologies, Inc. Modular segmented disc nucleus implant
US11246714B2 (en) 2012-03-16 2022-02-15 Sag, Llc Surgical instrument for implanting a semi-rigid medical implant
DE102018113809A1 (de) * 2018-06-11 2019-12-12 Christoph Karl Gelenkimplantat zur Gewebeneubildung am Gelenk

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