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
  • A61L24/00—Surgical adhesives or cements; Adhesives for colostomy devices
  • A61L24/04—Surgical adhesives or cements; Adhesives for colostomy devices containing macromolecular materials
  • A61L24/06—Surgical adhesives or cements; Adhesives for colostomy devices containing macromolecular materials obtained by reactions only involving carbon-to-carbon unsaturated bonds
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61L—METHODS OR APPARATUS FOR STERILISING MATERIALS OR OBJECTS IN GENERAL; DISINFECTION, STERILISATION OR DEODORISATION OF AIR; CHEMICAL ASPECTS OF BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES; MATERIALS FOR BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES
  • A61L2430/00—Materials or treatment for tissue regeneration
  • A61L2430/02—Materials or treatment for tissue regeneration for reconstruction of bones; weight-bearing implants

Definitions

• the present invention relates to cements and, in particular surgical cements such as bone cements and dental cements.
• Bone cements are frequently used in the fixation of prostheses to living bone. Such cements are typically polymeric materials. It is known to use acrylic monomers in the preparation of such polymeric cements, however, they suffer from the disadvantage that residual low molecular weight acrylates may be present in the cements and the cements may suffer from fatigue fractures. In addition, excessive heat may be generated on curing known cements.
• Bone cements described therein comprise a solid powder phase, eg. a bulking agent, comprising n-butyl methacrylate.
• a surgical cement comprising a bulking agent, a polymerisable monomer and an activator characterised in that the polymerisable monomer is an acrylate.
• the acrylate according to the invention may be a methacrylate and especially a compound of formula I,
• X is halogen, alkoxy C1 to 6, or (tr ialkylsiloxy) silyl.
• X When X is halogen it may be bromo, fluoro, iodo but preferably chloro.
• X (trialkylsiloxy)silyl
• the alkyl group defined therein may be alkyl C1 to 6, preferably alkyl C1 to 4 and especially methyl. It is not essential, but preferable, that the three alkyl groups in the trialkylsiloxy moiety are the same.
• n is preferably from 1 to 4.
• n is preferably 1 to 3 and especially 2.
• X is (trialkylsiloxy)silyl
• n is preferably 2 to 4 and especially 3.
• silyl methacrylate is tris (trimethylsiloxy)-3-silylpropyl methacrylate (TRIS) which is available from Fluorochem in the UK.
• haloalkyl methacrylate is 2-chloroethyl methacrylate (CEMA) which is available from Lancaster Synthesis in the UK.
• the surgical cement according to the invention may comprise a solid and a liquid component system.
• the solid component may comprise a bulking agent whilst the liquid component comprises a polymerisable monomer as hereinbefore defined and an activator.
• the bulking agent usually comprises a powdered methacrylate polymer, eg. a methacrylate such as polymethyl methacrylate (PMMA).
• a methacrylate such as polymethyl methacrylate (PMMA).
• the bulking agent may contain a compound or a mixture of compounds of formula I in polymerised form.
• activators Any conventionally known activators may be used, but preferred activators are toluidines and especially N-alkyl C1 to 6 toluidines, eg. N,N -dialkyl toluidines such as N,N-dimethyl toluidine.
• a polymerisation initiator will be required for the cement to cure.
• the initiator may be included in the solid component.
• Such initiators include radical initiators, such as peroxides, eg. benzoyl peroxide, thus polymerisation of the monomer, leading to cement setting or curing may start spontaneously when the solid and liquid components are mixed.
• redox initiators may be used.
• a redox initiator may be included in the solid or liquid component. Curing can be initiated in the presence of a redox initiator by the addition of water.
• Preferred oxidising or reducing agents of redox catalysts are those described in European Patent No.94222.
• One such preferred initiator may be sodium metabisulphite/Cu (II).
• the solid and liquid components may be supplied as a premixed cement.
• Polymerisation of the premixed cement may be initiated either by the addition of a radical initiator, or alternatively a redox initiator may be included in the premixed cement such that the initiation may be commenced by the addition of water.
• the initiator and the activator be in separate components of the system.
• the activator is preferably in the liquid component and thus the initiator is preferably in the solid component, or alternatively the initiator may be added separately, eg. to the premixed cement. It is a particular advantage of the redox catalysed system that the initiation reaction is catalysed by the addition of water which may be added separately.
• the cement according to the invention may optionally comprise a radio-opaque material.
• a radio-opaque material are preferably incorporated into the solid component phase. Any conventional radio-opaque materials may be used, but preferred materials include salts, such as zirconium and/or barium salts, eg. zirconium dioxide and/or barium sulphate.
• an improved surgical cement can be formulated which benefits from having one or more of the following properties: (i) a lower glass transition temperature material such as
• TRIS which has a crack blunting function and as such improves the fatigue properties of the surgical cement
• a readily activatable cement can be produced which, eg. on exposure to a water-activated polymerisation catalyst, produces a cement of good strength.
• the present invention in a still further aspect provides the use of a compound of formula I in the manufacture of a surgical cement or a component of a surgical cement as hereinbefore described.
• the compound of formula I accounts for 0.5 to 50% w/w of the solid and liquid component system or of the premixed cement.
• the present invention is a still further aspect provides the use of a compound of formula I in the manufacture of a surgical cement or a component of a surgical cement as hereinbefore described.
• a water curable composition according to the invention may include those water-activatable vinyl polymerisation catalysts described in European Patent No.94222.
• Suitable vinyl polymerisation catalysts of this type are well known in the literature. Where the catalyst is a redox catalyst, the premixed cement may be in association with the oxidising agent or reducing agent or, preferably, both.
• the amount of catalyst used in the polymerisation process is suitably OJ to 10% by weight and preferably 0.2 approximately 3%, eg. 0.2 to 2% by weight of the prepolymer.
• those components containing polymerisable material may be in association with a polymerisation inhibitor to prevent premature polymerisation during its preparation and storage.
• Suitable polymerisation inhibitors include polymerisation inhibitors of the art.
• a favoured inhibitor for preventing premature polymerisation of such polymerisable materials, during storage is p-methoxyphenol.
• curing of the cements may be brought about by either mixing of the solid and liquid components or adding a suitable initiator or water to the premixed cement.
• surgical cement we mean bone cements and/or dental cements, although bone cements are preferred.
• a method of fixing a prosthesis into a patient which comprises the application of a surgical cement according to the invention to an implantable prosthesis prior or during implant.
• prosthesis we include surgical, ie. orthopaedic, or dental, ie. orthodontic prostheses.
• the liquid component for a 4 bone cement formulations are shown in Table I.
• Formulation 1 was the control.
• For each formulation each of the ingredients was measured into a small beaker and mixed thoroughly.
• dumbells were tested for ultimate tensile strength.
• the liquid component for 3 bone cement formulations are shown in Table I.
• Formulation 2 was the negative control and 3 the positive control.
• For each formulation each of the ingredients was measured into a small beaker and mixed thoroughly.
• each of the powder components were made up by mixing the dry ingredients in a 4oz bottle. To each the required liquid component was added and stirred in for 1 minute, evacuated for 1.5 minutes and then poured into dumbell moulds. After 30 minutes curing was complete and the dumbells were removed from their moulds.
• dumbells were x-rayed to determine relative film exposures.

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• Health & Medical Sciences (AREA)
• Animal Behavior & Ethology (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Surgery (AREA)
• Epidemiology (AREA)
• Life Sciences & Earth Sciences (AREA)
• Chemical & Material Sciences (AREA)
• General Health & Medical Sciences (AREA)
• Public Health (AREA)
• Veterinary Medicine (AREA)
• Materials For Medical Uses (AREA)
• Acyclic And Carbocyclic Compounds In Medicinal Compositions (AREA)
• Dental Preparations (AREA)

Applications Claiming Priority (5)

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• 1994
  • 1994-09-09 CA CA 2171429 patent/CA2171429A1/en not_active Abandoned
  • 1994-09-09 AU AU76185/94A patent/AU7618594A/en not_active Abandoned
  • 1994-09-09 WO PCT/GB1994/001970 patent/WO1995007107A1/en not_active Application Discontinuation
  • 1994-09-09 JP JP7508557A patent/JPH09502117A/ja active Pending
  • 1994-09-09 EP EP94926290A patent/EP0722346A1/en not_active Withdrawn

Non-Patent Citations (1)

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