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
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B17/00—Surgical instruments, devices or methods, e.g. tourniquets
  • 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, setting implements or the like
  • A61B17/68—Internal fixation devices, including fasteners and spinal fixators, even if a part thereof projects from the skin
  • A61B17/80—Cortical plates, i.e. bone plates; Instruments for holding or positioning cortical plates, or for compressing bones attached to cortical plates
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B17/00—Surgical instruments, devices or methods, e.g. tourniquets
  • 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, setting implements or the like
  • 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
  • A61B17/866—Material or manufacture
• • 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
  • A61F2/3804—Joints for elbows or knees for elbows
• • 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
  • A61L27/54—Biologically active materials, e.g. therapeutic substances
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61N—ELECTROTHERAPY; MAGNETOTHERAPY; RADIATION THERAPY; ULTRASOUND THERAPY
  • A61N1/00—Electrotherapy; Circuits therefor
  • A61N1/18—Applying electric currents by contact electrodes
  • A61N1/20—Applying electric currents by contact electrodes continuous direct currents
• • 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
  • A61F2002/2817—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]
• • 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
  • A61F2002/2821—Bone stimulation by electromagnetic fields or electric current for enhancing ossification
• • 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
  • A61F2002/30003—Material related properties of the prosthesis or of a coating on the prosthesis
  • A61F2002/3006—Properties of materials and coating materials
  • A61F2002/30062—(bio)absorbable, biodegradable, bioerodable, (bio)resorbable, resorptive
• • 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
  • A61F2002/30329—Connections or couplings between prosthetic parts, e.g. between modular parts; Connecting elements
  • A61F2002/30451—Connections or couplings between prosthetic parts, e.g. between modular parts; Connecting elements soldered or brazed or welded
• • 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
  • A61F2/46—Special tools or methods for implanting or extracting artificial joints, accessories, bone grafts or substitutes, or particular adaptations therefor
  • A61F2002/4631—Special tools or methods for implanting or extracting artificial joints, accessories, bone grafts or substitutes, or particular adaptations therefor the prosthesis being specially adapted for being cemented
• • 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
  • A61F2210/0004—Particular material properties of prostheses classified in groups A61F2/00 - A61F2/26 or A61F2/82 or A61F9/00 or A61F11/00 or subgroups thereof bioabsorbable
• • 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
  • A61F2220/00—Fixations or connections for prostheses classified in groups A61F2/00 - A61F2/26 or A61F2/82 or A61F9/00 or A61F11/00 or subgroups thereof
  • A61F2220/0025—Connections or couplings between prosthetic parts, e.g. between modular parts; Connecting elements
  • A61F2220/0058—Connections or couplings between prosthetic parts, e.g. between modular parts; Connecting elements soldered or brazed or welded
• • 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
  • A61F2310/00017—Iron- or Fe-based alloys, e.g. stainless steel
• • 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
  • A61F2310/00023—Titanium or titanium-based alloys, e.g. Ti-Ni 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
  • A61F2310/00029—Cobalt-based alloys, e.g. Co-Cr alloys or Vitallium
• • 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
  • A61L2300/00—Biologically active materials used in bandages, wound dressings, absorbent pads or medical devices
  • A61L2300/10—Biologically active materials used in bandages, wound dressings, absorbent pads or medical devices containing or releasing inorganic materials
  • A61L2300/102—Metals or metal compounds, e.g. salts such as bicarbonates, carbonates, oxides, zeolites, silicates
• • 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
  • A61L2300/00—Biologically active materials used in bandages, wound dressings, absorbent pads or medical devices
  • A61L2300/10—Biologically active materials used in bandages, wound dressings, absorbent pads or medical devices containing or releasing inorganic materials
  • A61L2300/102—Metals or metal compounds, e.g. salts such as bicarbonates, carbonates, oxides, zeolites, silicates
  • A61L2300/104—Silver, e.g. silver sulfadiazine
• • 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
  • A61L2300/00—Biologically active materials used in bandages, wound dressings, absorbent pads or medical devices
  • A61L2300/60—Biologically active materials used in bandages, wound dressings, absorbent pads or medical devices characterised by a special physical form
  • A61L2300/602—Type of release, e.g. controlled, sustained, slow
  • A61L2300/604—Biodegradation

Definitions

• the present invention relates to orthopaedic implants for the human and animal body and provides such implants which affect hone growth.
• the invention is concerned in particular, hut not exclusively, with an endoprosthetic orthopaedic device having means for promoting or inhibiting bone growth in a selected region proximate to the device.
• orthopaedic implant means any inanimate article (including a device) which is to be implanted for orthopaedic purposes in the human or animal body for a prolonged period.
• the term includes, for example, orthopaedic pins, plates and screws and artificial joints.
• References to "endoprosthetic implants” include the entire implant, parts thereof and fixing means therefor. Thus, in this Specification (including t.he Claims thereof) fixing pins and screws for use with endoprosthetic devices are included with the term “endoprosthetic implant”.
• Such direct contact betweeen bone and an implant member may occur where the plate is bolted to strengthen or join a broken bone, or where a component of a prosthetic joint is secured to a neighbouring bone.
• the reamed cavity is filled with a gap filling medium such as a cement, for example polymethylmethacrylate cement.
• a cement for example polymethylmethacrylate cement.
• the member is then pushed into the cement which sets quickly to secure the prosthesis in place.
• the materials used are selected to be as inert as possible and to try to reduce bone reabsorption around the insert.
• the source of power for the electrical activity has been a man-made pov/er source, and cessation of the electrical activity has been caused by an operator's decision to switch off the power source or by battery failure.
• these treatments have been essentially externally controlled medical treatments and have had as their object the healing of fractures in natural bone material.
• the present invention has a number of objects, and wide applications in different areas concerned with medical activities on and relating to bone. The objects are differently attained in different aspects of the invention, and in some senses relate to different preferred arrangements of the present invention.
• an orthopaedic implant (as hereinbefore defined) comprising a biologically inactive bio-acceptable structural component for implanting in, on or near bone material in the body, and a bioactive control component for implanting in, on or near said bone material, said control component interacting in situ in the bodily material to give an electrical and/or chemical effect for promoting or inhibiting bone growth in the region of said structural component and being bio-degradable by action non-harmful to the body in such a manner as to place a limit on the duration of the said promotion or inhibition of bone growth.
• the control component can be discrete from, attached to or integral with the structural component.
• the structural component can serve merely as a substrate for the control component but preferably constitutes an endoprosthetic implant.
• an endoprosthetic orthopaedic device including an endoprosthetic component of biologically inactive, bio- acceptable material for insertion in or otherwise attaching to bone material in the body, and a control component for implanting in or in the region of the said bone material in co-operation with the said endoprosthetic component, the control component consisting of or including bio-active material such as will interact with bodily material to give an electrical and/or chemical effect for promoting or inhibiting bone growth in the region of the endoprosthetic component, and the bio-active material being bio-degradable by action non-harmful to the body in such a manner as to place a limit on the duration of the said promotion or inhibition of bone growth.
• bio-active material and the manner by which it promotes or inhibits bone growth may vary widely, and there will be set out hereinafter a number of particularly preferred forms of the bio-active material, and of the nature of the activity intended to take place in the body to promote or inhibit bone growth.
• bio-activity which may be carried cut in connection with the invention.
• the materials of the endoprosthetic component and the control component are such as to produce by interaction with each other and with bodily materials an electrical activity such as to promote or inhibit bone growth, for example the bio-active material being chosen to act as a sacrificial cathode for producing an area of electrical negativity which promotes bone growth.
• the bio-active material being chosen to act as a sacrificial cathode for producing an area of electrical negativity which promotes bone growth.
• the endoprosthetic component is an elongate member for insertion in a cavity in a bone
• the control component is in the form of a hollow cap or ring adapted to receive the end of the elongate member.
• the endoprosthetic component is made of titanium and/or titanium alloy and the control component is made of surgical steel carrying a layer of brazing or silver solder.
• the quantity of bio-active material provided in the implant device may be chosen so as to predetermine the duration of the promotion or inhibition of bone growth, until the bio-degradation of the bio-active material brings about substantial cessation of the bone growth or inhibition.
• the endoprosthetic component and the control component may be assembled either before, during or after the insertion of the components in the"body.
• the assembly may be put together by firstly inserting in a cavity in bone material the control component, followed by insertion of the endoprosthetic component into the cavity.
• a component for an endoprosthetic orthopaedic device the endoprosthetic component being adapted for insertion in or otherwise attaching to bone material in the body and having a composite form comprising biologically inactive bio-acceptable material and bio-active material such as will interact v/ith bodily material to give an electrical and/or chemical effect for promoting or inhibiting bone growth in the region of the endoprosthetic component, the bio-active material being bio-degradable by action non-harmful to the body in such a manner as to place a limit on the duration of the said promotion or inhibition of bone growth.
• the bio- active material may conveniently be provided for example by a layer of bio-active material formed directly on part of the said member of biologically inactive material.
• the inactive member may comprise an elongate member of a prosthesis intended to be secured in a cavity reamed in a bone, and the bio-active material may take the form of a layer of brasing formed on the end of the elongate member.
• bio-active material may be deposited by plating, or by ion deposition, or by impaction (for example D gun coating).
• an endoprosthetic orthopaedic device when the endoprosthetic orthopaedic device is inserted in situ in the body.
• an endoprosthetic orthopaedic device when inserted in the body, the device including an elongate member of biologically inactive, bio-acceptable material inserted in bone material in the body, and bio-active material in the region of the inserted end of the elongate member, the bio-active material being such as will interact with bodily material- to give an electrical and/or chemical effect for promoting bone growth in the region of the inserted end of the endoprosthetic member and being bio-degradable by action non-harmful to the body in such a manner as to limit the duration of the said promotion of bone growth.
• the invention provides particular advantage in that the siting of the material in the region of the inserted end of the elongate member can be arranged to produce bone growth at a region of the bone which is particularly susceptible to breakage after the insertion of the distal end of an endoprosthetic component.
• the endoprosthetic orthopaedic device may conveniently be made of titanium, or titanium alloy, or cobalt chrome molybdenum alloy, or ceramic material, or synthetic plastics material, or any combination of these materials.
• an implant structure for assisting or replacing mechanical bone function in the body comprising a functional structural member of biologically inactive bio-acceptable material for insertion in or otherwise attaching to bone material in the body, and a bio-active material such as will interact with bodily material to give an electrical and/or chemical effect for promoting or inhibiting bone growth in the region of the inactive member, the bio-active material being bio-degradable by action non-harmful to the body in such a manner as to place a limit on the said promotion or inhibition of bone growth, and the said structural member being such as to retain its mechanical integrity and to be bio-acceptable in the body after the bio-degrading of the active material.
• the said functional structural member may for example consistof a plate fastened to a bone across a fracture and intended to strengthen the bones after healing has taken place.
• the biologically inactive component is a functional structural member, e.g. having a purpose in the body after the bio-degrading of the bio-active material, and it is a feature that the structural member retains its mechanical integrity after the bio-degrading of the active material.
• a control device for control of bone growth the control device being adapted for implanting in the body in or in the region of bone material, and having a composite form comprising biologically inactive bio-acceptable material, and bio-active material such as will interact with bodily material to give an electrical and/or chemical effect for promoting or inhibiting bone growth, the bio-active material being bio-degradable by action non-harmful to the body in such a manner as to place a limit on the duration of the said promotion or inhibition of bone growth and in such a manner as to leave the control device in a bio-acceptable condition to remain in the body after the bio-degrading of the active material.
• an endoprosthetic orthopaedic device a component of an endoprosthetic orthopaedic device, an endoprosthetic orthopaedic device when inserted in the body, an implant structure and a control device.
• these items will be referred to by the general term apparatus when considering further features of the invention.
• biologically inactive, bio-acceptable material means a material which is normally acceptable to the body as an implant material and does not of itself interact with normal bodily materials.
• bio-active material a material which either by itself, or when in combination with the said biologically inactive material, will normally interact electrically and/or chemically with bodily materials when implanted in the body.
• bio-degrading a change in the chemical structure of a material by interaction with bodily material when the material is implanted in the body.
• the bio-degrading may take the form of dissolving the bio-active material to limit the bone promotion or inhibition, or alternatively the bio- degrading may take the form of a build-up of corrosion products on the surface at which the said electrical and/or chemical effect takes place.
• the said bio-active material may conveniently be such as to promote or inhibit bone growth as a result of a combined inter- action between the bio-active material and the said inactive material v/hen in contact with bodily materials when implanted in the body.
• the said inactive material and the said bio-active material are such as to produce by interaction with bodily materials a region of electrical polarity and/or a flow of electrical current such as to promote or inhibit bone growth.
• the said two materials are selected to be such that in use when implanted in the body the bio-active material acts as a sacrificial cathode producing an area of electrical negativity to promote bone growth.
• the said non-harmful bio-degradation of the bio-active material may take a number of forms.
• the bio-degraded material may be secreted by the body as a waste product, or may be distributed around the body and stored in a non-harmful form.
• the said bio-active material may be such that the said promotion or inhibition of bone grov/th and the said bio-degradation of the active material takes place by electro-chemical activity in v/hich the active material is dissipated as ions which are stored or secreted by the body without harm to the body.
• the said biologically inactive material consists of titanium and/or titanium alloy and/or cobalt chromium molybdenum alloy.
• the titanium alloy may comprise titanium alloy Type 318, v/hich is an alloy of 6% aluminium and 4% vanadium.
• the said bio-active material may conveniently include or consist of one or more of the elements comprising iron, copper, tin, zinc or silver, and may conveniently consist of a layer of brazing or silver solder, for example on surgical stainless steel.
• the bio-active material is located in a position such as to inhibit bone growth in the region of a joint in an endoprosthetic orthopaedic device. It is often found that when an endoprosthetic orthopaedic device is inserted, unwanted bone growth occurs in the region of the joint during an initial period when the device is being accepted by the body.
• apparatus may be implanted having means for inhibiting this unwanted bone growth for a limited time interval determined by the bio-degradation of the said bio-active material. After the acceptance of the device by the body, no further inhibition of bone growth is required.
• the bio-active material may be located in a position such as to promote bone growth in the region of the inserted end of an elongate member of an endo- prosthetic orthopaedic device where said end is inserted in bone material.
• this region at the end of an inserted endoprosthetic component is particularly vulnerable to breakage, and a thickening of bone at this region is particularly advantageous.
• the invention may be used to promote bone growth around an endoprosthetic component so as to secure the component more safely in the bone material. It will be appreciated that the present invention differs in a number of respects from the previously known art in relation to bone treatment.
• the present invention differs from present practice in the choice of materials for endoprosthetic devices in that a deliberate choice is made of a bio-active material to be included in the endoprosthetic device, whereas present practice tends to the selection of materials which are to the greatest extent possible bio-passive and bio-acceptable.
• the invention rests upon the realisati on that inclusion of a limited quantity of bio-active material in an endoprosthetic device can produce a beneficial result when carrie d out over a limited time interval .
• the present invention is distinguished by virtue of the fact that the power source for the electrical activity (in the particular, appropriate aspect of the inventi on) is provided by the bio-active material itself si tuated in the body.
• the prior art is also distinguished in this aspect in that the terminati on of the electrical activity is not required to be triggered by an external switching-off of the power source , but arises naturally by the bio-degradati on of the bio- active material .
• biologically inactive material v/hich is intended to remain, in the body (eg as a permanent implant) after cessati on of the bio-activity and bio- degradati on.
• biologically inactive material v/hich is intended to remain, in the body (eg as a permanent implant) after cessati on of the bio-activity and bio- degradati on.
• the end result uas an ineffective faulty endoprosthetic device uhich deteriorated by massive corrosion until it could no longer perform its required function.
• a member of biologically inactive mateiral uhich retains its mechanical integrity after the cessation of bio-acti ⁇ ity.
• connection uith these general statements of the present in ⁇ ention, there uill be set out a number of features in connection uith a method according to the present invention.
• the method of the present invention is applicable to the bodies of animals in addition to the human body.
• a method of implanting an endoprosthetic orthopaedic device in the body including the steps of implanting in the body in the region of an endoprosthetic orthopaedic device an amount ⁇ f bio-actiue material to produce bone grouth or inhibition of bone grouth by an electrical and/or chemical effect resulting from interaction of tne active material uith bodily material, and to produce non-harmful bio-degrariat i on of the active material uith bodily material so as to place a limit on the duration of the bone growth or inhibition.
• a method of assisting or replacing mechanical bone function in the body comprising inserting in or otherwise attaching to bone material in the body a member of biologically inactive, bio-acceptable material, implanting in the bone material or in the region thereof an amount of bio-active material to produce bone growth or inhibition of bone growth by an electrical and/or chemical effect resulting from interaction of the active material with bodily material and to produce non- harmful bio-degradation of the active material by interaction of the active material with bodily materials so as to place a limit on the duration of the bone growth or inhibition, and maintaining the said inactive member as an implant in the body after the bio-degrading of the active material and substantial cessation of bio-activity, v/ith the mechanical integrity of the inactive member substantially unaffected by the bio-activity of the active material.
• a method of controlling bone grov/th in a selected region of bone material in the body comprising the steps of implanting in the body in or in the region of bone material a control device ha ⁇ ing a composite form comprising biologically inactive, bio-acceptable material, and bio-acti ⁇ e material, said bio-active material producing bone grouth or inhibition of bone grouth by an electrical and/or chemical effect resulting from interaction of the active material with bodily material ⁇ and the duration of the bone growth or inhibition being limited by non-harmful bio-degradation of the active material by interaction of the active material uith bodily material.
• Figure 1 is a diagrammatic representation of a section through the distal end of an endoprosthetic component
• Figure la is a diagrammatic cross-section through the end of an endoprosthetic component shouing an optional feature for securing the component;
• Figure 2 is a drawing taken from an X-ray of an endoprosthetic orthopaedic device comprising an elbow joint in situ at the time of implanting; and Figure 3 is a drawing taken from an X-ray of the same endoprosthetic device at a time approximately five years after the implantation.
• a member 11 comprises an elongate member of an endoprosthetic device 13 consisting of an elbow joint.
• the member 11 is situated in a reamed out cavity 14 in the medulary canal 15 of a forearm bone 16.
• a control component comprising an implanted element 17 in the form of a cap.
• the element 17 comprises a main body 18 having on its interior surface a layer 19 of bio-active material such as will interact with bodily material to give an effect as will be described hereinafter to promote bone growth.
• the main body 18 is in the shape of a cap co-operating with the end of the member 11, and has a threaded extension 20 which protrudes into the unreamed medulary canal 15.
• the space between the member 11 and the reamed cavity 14 is filled by a gap filling medium 26 such as bone cement.
• the endoprosthetic member 11 may conveniently be made of titanium alloy type 318, and the bone cement 26 may be conventional poly methyl methacrylate.
• the main body 18 of the cap element 17 may be formed of the same titanium alloy 318, or may be formed of surgical stainless steel, or cobalt chromium molybdenum alloy.
• the layer 19 of bio-active material may comprise a layer of brazing having a composition of, for example, 60% copper, 35% tin, with trace elements of manganese silicon and nickel, and the remainder of the composition zinc.
• the layer 19 may- comprise silver solder of a commonly available commercial .composition having a basic formula of 50% silver with the remainder composed of copper and zinc.
• the element may be for example 2i centimetres long and 4 millimetres in diameter at its upper open end.
• the layer 19 of bio-active material may extend around the entire interior surface of the element 17 as shown, or alternatively the layer may comprise a layer of brazing or silver solder which extends for only one- half centimetre down the main body 18 from the open end thereof (see Figure lb) .
• perforations 25 in the hollow cap part of the main body 18 extending through to the interior of the cap.
• the extension 20 is conveniently either a force fit in the medulary canal 15, or is threaded so as to be secured to the interior surface of the canal.
• the medulary canal 15 is reamed out in conventional manner by a surgical reamer to a depth sufficient to accept the member 11, and slightly oversize of the member 11, terminating in a step 22.
• the element 17 is lodged on the end of an inserting rod (not shown) and is pushed down the reamed cavity 14 until the extension 20 lodges in the medulary canal 15.
• the inserting rod co-operates with flanges on the interior of the element 17 so that the inserting rod can be rotated and threads on the extension 20 can be engaged with the interior of the medulary canal 15.
• the inserting rod is so arranged that a slight reverse turn releases the inserting rod from the element 17 and the inserting rod can be withdrawn leaving the element 17 in place.
• the reamed cavity 14 is filled by conventional means with a bone cement 21 and finally the member 11 is pushed through the bone cement down into the cavity 14 so as to lodge in the element 17.
• the member 11 it is thought to be advantageous for the member 11 to have a number of points of contact, if not a complete area of contact, with the interior of the element 17, and to this effect the exterior of the end of the member 11 may be formed with outwardly- extending peaks or serrations indicated at in Figure la. These protrusions nsure good contact with the element 17.
• the interior of the element 17 may have internally-projecting ribs or protrusions which effect the same connection v/ith a smooth ended member 11. It will be appreciated that some bone cement 21 will be carried into the interior of the element 17 by the member 11, but it is generally found that sufficient contact is made between the member 11 and the .element 17 by the member 11 being forced into the element 17.
• the member 11 is substantially straight, it is possible to affix the cap element 17 directly onto the member 11 before insertion in the bone, and the securing of the element 17 can be effected by rotating the entire member 11 so as to screw the extension 20 into the medulary canal 15.
• the layer of brazing or silver solder 19 may be applied directly to the end of the member 11, and the element 17 may be a plain titanium alloy.
• the element 17 consists of a main body 18 of surgical cutting steel to British Standard EN 56D having a layer of silver solder or brazing to a depth of one-half centimetre along a 2 centimetre long implant (as shown in Figure lb), and having a diameter of 4 millimetres.
• the member 11 was Inserted as a force fit in the interior of the element 17, and in this example no perforations were provided through the element 17.
• the element 17 was threaded as shown In Figure lb and had been firmly screwed into the medulary canal 15.
• Figure 2 is a drawing taken from an X-ray taken at the time of implant in the patient
• Figure 3 is a drawing taken from an X-ray taken of the same insert approximately five years later.
• the thickening of bone in this region at the distal end of a prosthetic component is particularly advantageous since it is at this region that the bone is particularly susceptible to breakage due to the stiffening effect of the endoprosthetic member in. the bone.
• the bone is particularly susceptible to breaking where this stiffening effect terminates, and the bone thickening shown in Figure 3 occurs at this region which is normally a region of weakness.
• the layer 19 consistitutes bio-active material which bio- degrades by electro-chemical action and dissolves into ions which are non-harmful to the body and which are distributed by bodily fluids av/ay from the implant, either to be stored by the body in non-harmful manner, or to be secreted from the body, or to be dissipated by a combination of these effects. It is believed that the effect is dependent upon, or enhanced by contact between the element 17 and the bone structure, and by contact betv/een the member 11 and the element 17. It is also believed that in other arrangements, the effect may be enhanced by perforations through the element 17 allowing a greater area of contact of bodily materials with both the main body 18 and the layer 19 of bio-active material.
• the separate implant elements may consist of one or more bands or rings of metal such as plain iron, inserted into the bone at a distance spaced from the main structural member.
• bio-active material which reacts in only a chemical reaction with the bodily fluids, so as to lay down material suitable for promoting bone growth, such as calcium.
• the bio-active material is chosen to be bio-degradable, so as to provide the same limit on the duration of the chemical activity which promotes the bone growth.
• the bone growth may be achieved by producing bone salt, by laying down calcium apertite.
• the activity produced by the bio-active material is electrical or electro-chemical in nature, and is such as to produce a flow of current, it Is believed that the current required is in the range of 20 to 120 microamps.
• the invention will be referred to in its general terms as involving the use of an implant element of biologically inactive bio-accept- able material, and bio-active material such as will interact with bodily material to give an electrical and/or chemical effect to promote or inhibit bone growth.
• an implant element of biologically inactive bio-accept- able material and bio-active material such as will interact with bodily material to give an electrical and/or chemical effect to promote or inhibit bone growth.
• bio-active material such as will interact with bodily material to give an electrical and/or chemical effect to promote or inhibit bone growth.
• Clearly one primary application of the invention is in the production of bone grov/th at the distal end of an endoprosthetic orthopaedic component, as has been described.
• another application of the invention lies in controlled promotion of bone growth in the region of a repair plate screwed or otherwise secured to a fractured bone across the fracture to strengthen the bone during healing.
• the bio-active material may be arranged to be such as to inhibit bone growth.
• the bone is inhibited from grov/th, or may reabsorb. Difficulty is often found in implanting endoprosthetic devices including joints, that during the initial period of acceptance of the joint in the body, unwanted growth of bone occurs around the joint.
• bio-active material may be provided in association with the endoprosthetic insert such that an area of positive electrical polarity is provided in the region of the joint to inhibit bone growth during the initial period of acceptance of the insert.
• the bio-active material is again made bio-degradable, so that the duration of the activity is terminated after degradation of the bio-active material.
• This duration of activity is arranged to coincide with the normal period in which there is a danger of excess bone grov/th around the joint.

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• 1981
  • 1981-03-26 JP JP56500927A patent/JPS57500589A/ja active Pending
  • 1981-03-26 WO PCT/GB1981/000059 patent/WO1981002668A1/en active IP Right Grant
  • 1981-03-26 IE IE677/81A patent/IE52687B1/en unknown
  • 1981-03-26 EP EP81900651A patent/EP0048247B1/en not_active Expired
  • 1981-03-26 DE DE8181900651T patent/DE3164658D1/de not_active Expired

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