Joint device and method
11957588 ยท 2024-04-16
Inventors
Cpc classification
A61L31/148
HUMAN NECESSITIES
A61F2002/30563
HUMAN NECESSITIES
A61B17/74
HUMAN NECESSITIES
A61F2002/30757
HUMAN NECESSITIES
A61F2002/30754
HUMAN NECESSITIES
A61F2002/4631
HUMAN NECESSITIES
A61F2002/4628
HUMAN NECESSITIES
A61F2002/30583
HUMAN NECESSITIES
A61B17/562
HUMAN NECESSITIES
A61F2002/3241
HUMAN NECESSITIES
A61F2002/30878
HUMAN NECESSITIES
C08L5/08
CHEMISTRY; METALLURGY
A61F2/30942
HUMAN NECESSITIES
A61B17/1637
HUMAN NECESSITIES
A61L27/58
HUMAN NECESSITIES
A61F2002/30668
HUMAN NECESSITIES
A61F2002/30065
HUMAN NECESSITIES
A61F2002/30507
HUMAN NECESSITIES
A61F2002/3483
HUMAN NECESSITIES
A61F2002/30759
HUMAN NECESSITIES
A61B17/8811
HUMAN NECESSITIES
A61F2002/3631
HUMAN NECESSITIES
A61B17/8805
HUMAN NECESSITIES
A61F2/3603
HUMAN NECESSITIES
A61F2002/30032
HUMAN NECESSITIES
A61F2002/30675
HUMAN NECESSITIES
A61L27/16
HUMAN NECESSITIES
A61F2/30723
HUMAN NECESSITIES
A61F2002/3615
HUMAN NECESSITIES
A61F2002/30471
HUMAN NECESSITIES
A61B17/86
HUMAN NECESSITIES
A61F2250/00
HUMAN NECESSITIES
A61B17/8802
HUMAN NECESSITIES
A61F2002/4627
HUMAN NECESSITIES
A61F2002/30579
HUMAN NECESSITIES
C08L5/08
CHEMISTRY; METALLURGY
A61F2/3601
HUMAN NECESSITIES
International classification
A61B17/16
HUMAN NECESSITIES
A61B17/56
HUMAN NECESSITIES
A61B17/88
HUMAN NECESSITIES
A61L27/22
HUMAN NECESSITIES
Abstract
A mould adapted to be introduced into a joint of a human patient for resurfacing at least one carrying contacting surface of said joint is provided. The mould is adapted to receive material for resurfacing at least one carrying contacting surface of said joint. The mould is further adapted to be resorbed by the human body or melt after having served its purpose.
Claims
1. A mould adapted to be introduced into a joint of a human patient for resurfacing at least one carrying contacting surface of the joint, wherein said mould is adapted to receive material for resurfacing said at least one carrying contacting surface of the joint, and wherein said mould comprises a mould material adapted to chemically react with a fluid injected into said mould such that said mould melts or is resorbed by the human patient after having served the mould's purpose.
2. The mould according to claim 1, wherein said mould comprises a collagen-based material.
3. The mould according to claim 2, wherein said mould is adapted to receive collagenase, and wherein the material of said mould is affected by the injection of the collagenase such that the mould melts or is resorbed faster than without the injection of the collagenase.
4. The mould according to claim 1, wherein said mould comprises a chitosan-based material.
5. The mould according to claim 4, wherein said mould is adapted to receive lysozyme, and wherein the material of said mould is affected by the injection of the lysozyme such that the mould melts or is resorbed faster than without the injection of the lysozyme.
6. The mould according to claim 1, wherein said mould material is adapted to be melted by a temperature of the received material.
7. The mould according to claim 1, wherein said received material comprises at least one material selected from the group consisting of: a. polytetrafluoroethylene, b. perfluoroalkoxy c. fluorinated ethylene propylene, d. polyethylene, and e. acrylic polymer mixed with alumina trihydrate.
8. The mould according to claim 1, wherein said mould is adapted to be melted by the received material having a temperature in the interval 40-60 degrees Celsius, or in the interval 60-90 degrees Celsius, or in the interval 90-200 degrees Celsius, or in the interval 200-400 degrees Celsius or more than 400 degrees Celsius.
9. The mould according to claim 1, wherein the joint is a hip joint and said mould is collapsible such that said mould can be introduced into the hip joint through a hole in any of: a pelvic bone, a femoral bone and a hip joint capsule.
10. The mould according to claim 1, wherein the joint is a knee joint and said mould is collapsible such that said mould can be introduced into the knee joint through a hole in any of: a femoral bone, a tibia bone and a knee joint capsule.
11. The mould according to claim 1, further comprising an injecting entrance in said mould adapted to receive the fluid injected into said mould.
12. A mould adapted to be introduced into a joint of a human patient for resurfacing at least one carrying contacting surface of the joint, wherein said mould is adapted to receive material for resurfacing said at least one carrying contacting surface of the joint, and wherein said mould comprises a mould material adapted to chemically react with a fluid injected into said mould such that said mould melts or is resorbed by the human patient after having served the mould's purpose wherein said mould comprises a hyaluronan-based material.
13. The mould according to claim 12, wherein said mould is adapted to receive hyaluronidase, and wherein the material of said mould is affected by the injection of the hyaluronidase such that the mould melts or is resorbed faster than without the injection of the hyaluronidase.
14. A mould adapted to be introduced into a joint of a human patient for resurfacing at least one carrying contacting surface of the joint, wherein said mould is adapted to receive material for resurfacing said at least one carrying contacting surface of the joint, and wherein said mould comprises a mould material adapted to chemically react with a fluid injected into said mould such that said mould melts or is resorbed by the human patient after having served the mould's purpose, wherein said mould comprises a fibrin-based material.
15. The mould according to claim 14, wherein said mould is adapted to receive plasmin, and wherein the material of said mould is affected by the injection of the plasmin such that the mould melts or is resorbed faster than without the injection of the plasmin.
Description
BRIEF DESCRIPTION OF DRAWINGS
(1) The embodiments are now described, by way of example, with reference to the accompanying drawings, in which:
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DETAILED DESCRIPTION
(45) Before the present invention is described, it is to be understood that the terminology employed herein is used for the purpose of describing particular embodiments only and is not intended to be limiting, since the scope of the present invention will be limited only by the appended claims and equivalents thereof.
(46) It must be noted that, as used in this specification and the appended claims, the singular forms a, an, and the include plural referents unless the context clearly dictates otherwise.
(47) Also, the term about is used to indicate a deviation of +/?2% of the given value, preferably +/?5%, and most preferably +/?10% of the numeric values, where applicable.
(48) In addition to the above, the following terms will be used:
(49) Biocompatible material is to be understood as being a material with low level of immune response. Biocompatible materials are sometimes also referred to as biomaterials. Analogous is biocompatible metals a metal with low immune response such as titanium or tantalum. The biocompatible metal could also be a biocompatible alloy comprising at least one biocompatible metal.
(50) Form fitting is to be understood as an element having a part or section which is adapted to enable a mechanical connection of said element to at least one other element using said part or section. Form fitted structure is a structure of an element which enables form fitting.
(51) Elasticity is to be understood as a materials ability to deform in an elastic way.
(52) Elastic deformation is when a material deforms under stress (e.g. external forces), but returns to its original shape when the stress is removed. A more elastic material is to be understood as a material having a lower modulus of elasticity. The elastic modulus of an object is defined as the slope of its stress-strain curve in the elastic deformation region. The elastic modulus is calculated as stress/strain, where stress is the force causing the deformation, divided by the area to which the force is applied; and strain is the ratio of the change caused by the stress.
(53) Stiffness is to be understood as the resistance of an elastic body to deformation by an applied force.
(54) Functional hip movements are to be understood as movements of the hip that at least partly correspond to the natural movements of the hip. On some occasions the natural movements of the hip joint might be somewhat limited or altered after hip joint surgery, which makes the functional hip movements of a hip joint with artificial surfaces somewhat different than the functional hip movements of a natural hip joint.
(55) The functional position of an implantable medical device or prosthesis is the position in which the hip joint can perform functional hip movements.
(56) Functional hip joint is a hip joint that can perform functional hip movements either with or without an implanted medical device or prosthesis.
(57) The medical device according to any of the embodiments could comprise at least one material selected from a group consisting of: polytetrafluoroethylene (PTFE), perfluoroalkoxy (PFA) and fluorinated ethylene propylene (FEP). It is furthermore conceivable that the material comprises a metal alloy, such as cobalt-chromium-molybdenum or titanium or stainless steel, or polyethylene, such as cross-linked polyethylene or gas sterilized polyethylene. The use of ceramic material is also conceivable, in the contacting surfaces or the entire medical device such as zirconium ceramics or alumina ceramics. The part of the medical device in contact with human bone for fixation of the medical device to human bone could comprise a poorhouse structure which could be a porous micro or nano-structure adapted to promote the growth-in of human bone in the medical device for fixating the medical device. The porous structure could be achieved by applying a hydroxy-apatite (HA) coating, or a rough open-pored titanium coating, which could be produced by air plasma spraying, a combination comprising a rough open-pored titanium coating and a HA top layer is also conceivable. The contacting parts could be made of a self lubricated material such as a waxy polymer, such as PTFE, PFA, FEP, PE and UHMWPE, or a powder metallurgy material which could be infused with a lubricant, which preferably is a biocompatible lubricant such as a Hyaluronic acid derivate. It is also conceivable that the material of contacting parts or surfaces of the medical device herein is adapted to be constantly or intermittently lubricated. According to some embodiments the parts or portions of the medical device could comprise a combination of metal materials and/or carbon fibers and/or boron, a combination of metal and plastic materials, a combination of metal and carbon based material, a combination of carbon and plastic based material, a combination of flexible and stiff materials, a combination of elastic and less elastic materials, Corian or acrylic polymers.
(58) In the following a detailed description of embodiments will be given. In the drawing figures, like reference numerals designate identical or corresponding elements throughout the several figures. It will be appreciated that these figures are for illustration only and are not in any way restricting the scope. Thus, any references to direction, such as up or down, are only referring to the directions shown in the figures. Also, any dimensions etc. shown in the figures are for illustration purposes.
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(63) 4b shows the knee joint in section from the side. The condyles 105 is the lower extremity of the femoral bone 210 and makes up the sides of the upper part of the knee joint. Tibia 510 or the shinbone constitutes the lower part of the knee joint, tibia is in connection with fibula 511 or the calf bone, tibia and fibula constitutes the bones of the lower part of the leg.
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(68) Before the introduction of a mould or material into the hip joint the hip joint surfaces could need to be prepared. This preparation could be performed by reaming the acetabulum and/or the caput femur surface.
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(73) To get a view inside the hip joint it is conceivable that the surgeon can make a second hole in the pelvic bone, the femoral bone or the hip joint capsule to insert a camera.
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(77) After the preparation of the surfaces the mould needs to be inserted into either the hip joint or the knee joint.
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(85) The sterile mould is inserted in a hip joint, and a liquid polymer mixture is injected into said mould, filling said mould, whereby said mold in its filled state takes the shape of an acetabular cup. The polymer mixture is cured in said mould, and retains the shape defined by said mould, whereupon said polymer film forming the mould is resorbed, leaving a cured polymer solid in the shape of an acetabular cup.
(86) The biologically resorbable film is chosen from films and membranes made of polylactide polymers, polyglycolide polymers, polycaprolactone polymers, or lactide/glycolide copolymers, or lactide/caprolactone cellulose-based film; a hyaluronan-based film, a fibrin-based film, a collagen-based film, a chitosan-based film or combinations thereof.
(87) A non-limiting example of a bioabsorbable membrane is the Cytoskin? membrane (Biogeneral Inc., San Diego, CA, USA) available in a thickness of 12 ?m to 150 ?m. Other bioabsorbable materials are exemplified by the Purasorb? product line (Purac Biomaterials, Gorinchem, The Netherlands). The Purasorb? materials can be processed by conventional processing techniques, such as extrusion, compression molding and injection molding, and can be subjected to different sterilization techniques. These materials are commercially available in the form of various resorbable orthopedic implant devices. With the advantages of excellent biocompatibility and biodegradability they serve as the matrix in a wide variety of applications to treat injuries of the muscoskeletal system in areas such as sports medicine, trauma and spinal surgery. Further, the properties of the Purasorb? polymers can be tailored to the application to meet all the design criteria.
(88) Clinical experience in a large number of cases shows that a lactic acidglycolic acid copolymer is resorbed in 12-15 months in craniosynostosis surgery. It is very likely that the resorption time in a joint would be shorter, as the film will be subject to mechanical wear.
(89) The liquid polymer mixture is chosen from polytetrafluoroethylene, perfluoroalkoxy propylene, fluorinated ethylene propylene, polyethylene, and highly crosslinked polyethylene.
(90) Another example of embodiment is a resorbable mould with accelerated resporption. The biological resorption of the mould is accelerated by the introduction of an agent taking part in, or accelerating, the resorption. When the film for example comprises a hyaluronan-based material, hyaluronidase can be added in a suitable amount, when the film comprises a fibrin-based material, plasmin is added in a suitable amount, when the film comprises a collagen-based material, collagenase is added in a suitable amount, and when the film comprises a chitosan-based material, lysozyme is added in a suitable amount.
(91) Another example of embodiment is a resorbable mould with inner coating. As in the previous embodiments the mould is produced from a biologically resorbable polymer film, for example but not limited to the Cytoskin? membrane (Biogeneral Inc.). The inside of the mould is coated with a biocompatible compound which improves the properties of the acetabular cup, for example reduced friction, increases surface strength, reduces wear etc. A non-limiting example of such coating is a biocompatible phospholipid polymer, 2-methacryloyloxyethyl phosphorylcholine (MPC) shown to form a hydrated lubricating layer, significantly decreasing friction and wear, reducing the amount of wear particles compared to uncoated joint surfaces.
(92) When the mould is filled with the polymer mixture intended to form the acetabular cup, the MPC-coating will be grafted into the outer surface of the solid polymer, significantly reducing friction and wear. The mould itself will be resorbed through the action of natural resorption mechanisms, or resorption mechanisms augmented through the addition of suitable agents, as described above, exposing the coated surface.
(93) Another example of embodiment is a mould that melts and integrates with core. In order to form an acetabular cup inside a hip joint, using a polymer mixture, e.g. a polymer having a melting point in the interval 40-60? C., or 40-90? C., or 40-200? C., or 40 to 400? C., a mould is produced from a polymer film, said polymer chosen from polymers having the same or lower melting point as said polymer.
(94) Said mould is shaped to fit into the acetabular fossa and to define the shape and volume of an acetabular cup. The mould is sterilized and evacuated.
(95) The mould is inserted in a hip joint, and a heated liquid polymer mixture is introduced e.g. injected into said mould, the temperature of the liquid polymer mixture being above both the melting point of the polymer mixture, and above the melting point of the polymer forming the mould. When filling said mould, the heated polymer contacts and melts the film forming the mould, and seamlessly integrates with said film.
(96) Another example of embodiment is a mould that melts and is absorbed by core. An alternative to the examples described above is that the biocompatible material forming the mould, and the polymer material forming the core of the artificial acetabular cup, are chosen so that the material forming the mould will be resorbed by the material forming the core. In order to achieve this, a skilled person will need to study the melting temperature of the materials, the surface properties, charge and other properties of the materials. The material forming the mould and the material forming the core are chosen so that the material forming the mould will be absorbed by the core material.
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(103) After the mould has been placed in the hip or knee joint it is filled with a fluid adapted to harden to a medical device adapted to serve as at least one artificial joint surface.
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(119) According to another embodiment (not shown) the fluid is adapted to harden through the mixing with a gas. In which case one of the two compartments is adapted to hold a pressurized gas (such as nitrogen gas) adapted to act as catalyzing agent for the fluid adapted to harden. According to that embodiment the mixing unit 109 is adapted to mix one liquid and one gas fluid. Said first, second or mixed fluid could also be adapted to harden by means of UV-light, thermal change or contact with a body fluid.
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(121) Please note that any embodiment or part of embodiment as well as any method or part of method could be combined in any way. All examples herein should be seen as part of the general description and therefore possible to combine in any way in general terms.