Source: https://patents.google.com/patent/WO2005112833A1/en
Timestamp: 2019-06-17 22:54:15
Document Index: 623660139

Matched Legal Cases: ['arts 4', 'arts 2', 'art 6', 'arts 8', 'arts 8', 'art 12', 'art 18', 'art 22', 'arts 24', 'arts 28', 'art.\n16', 'art.\n17', 'art.\n18', 'art.\n19', 'art.\n22']

WO2005112833A1 - Improvements in and relating to surgical implants - Google Patents
Improvements in and relating to surgical implants Download PDF
WO2005112833A1
WO2005112833A1 PCT/GB2005/001967 GB2005001967W WO2005112833A1 WO 2005112833 A1 WO2005112833 A1 WO 2005112833A1 GB 2005001967 W GB2005001967 W GB 2005001967W WO 2005112833 A1 WO2005112833 A1 WO 2005112833A1
PCT/GB2005/001967
Christopehr Reah
2004-05-20 Priority to GB0411249.6 priority Critical
2004-05-20 Priority to GB0411249A priority patent/GB0411249D0/en
2004-09-30 Priority to GB0421635A priority patent/GB0421635D0/en
2004-09-30 Priority to GB0421635.4 priority
2005-05-20 Application filed by Pearsalls Limited filed Critical Pearsalls Limited
2005-12-01 Publication of WO2005112833A1 publication Critical patent/WO2005112833A1/en
IMPROVEMENTS IN AND RELATING TO SURGICAL IMPLANTS
Increasingly there is a desire to address problems with intervertebral discs by replacing all or part of the disc with a prosthetic disc, rather than fusing the adjacent vertebrae. A wide variety of designs of disc prostheses exist, including: articulated metal plates with a spring or like between them; metal end plates with a polyethylene spacer; and a spacer of elastomeric or visco-elastic material in a retaining fabric, US- 6093205. In the later two cases, the same material for the spacer is used in all examples of that type of prosthesis, irrespective ofthe prosthesis's size.
According to a first aspect of the present invention we provide a series of disc prostheses, the series including at least a first prosthesis and a second prosthesis, the first prosthesis differing in size and differing in one or more materials from which it is formed compared with the second prosthesis, the first and second prostheses being ofthe same type.
One type of disc prosthesis may be provided as a pair of, preferably rigid or semirigid, end plates with a core between them. The core may be bonded to the end plates. The core may be unbonded to the end plates. The core may be partially bonded to the end plates. The end plates may be metallic.
The prostheses may differ in size from one another so as to approximate to, and ideally match, the size of the natural intervertebral disc they are intended to replace. The prostheses may differ in one or more structural properties relative to one another so as to approximate to, and ideally match, one or more ofthe structural properties of the natural intervertebral disc they are intended to replace. Preferably the prostheses approximate to, and ideally match a plurality, and ideally all, of the structural properties ofthe natural intervertebral disc they are intended to replace.
The material of the end plates may differ between the first prosthesis and the second prosthesis. The material of the encapsulation may differ between the first prosthesis and the second prosthesis. Preferably the material of the core may differ between the first and the second prosthesis. The material, particularly the material of the core, may differ due to the material used to form it and/or the grade of material used to form it and/or due to one or more additives and/or the level thereof. The material, particularly the material of the core may differ due to the treatment of the material before and/or during and/or after production. In particular, the material may differ due to the curing conditions to which it is subjected. The core may be caused to differ by varying a component thereof, for instance a filler.
According to a second aspect of the present invention we provide a method for producing disc prostheses, the method including forming disc prostheses of a first kind and forming disc prostheses of a second kind, the first prosthesis kind differing in size and differing in one or more materials from which it is formed compared with the second prosthesis kind, the first and second prostheses being ofthe same type.
According to a third aspect of the present invention we provide a surgical method for provide a disc prosthesis, the method including removing at least a part of the natural disc in a spine and inserting a disc prosthesis in the spine, the disc prosthesis being selected from a series of disc prostheses, the series including at least a first prosthesis and a second prosthesis, the first prosthesis differing in size and differing in one or more materials from which it is formed compared with the second prosthesis, the first and second prostheses being ofthe same type.
The top surface and/or bottom surface and/or sides of a medical device or component thereof may be provided by the first part(s). The top and bottom layers ofthe medical device or component thereof may be provided by the first part(s). An intermediate layer ofthe medical device or component thereof may be provided by the first part(s). One or two side portions ofthe medical device or component thereof may be provided by the first part(s). The majority of the medical device or component thereof may be provided by the first part(s). A plug and/or insert of the medical device or component thereof may be provided by the first part(s). One or more flexible members of the medical device or component thereof may be provided by the first part(s). The flexible members may be elongate and/or longitudinally aligned with one another and/or surrounded by an at least partial enclosure.
The top surface and/or bottom surface and/or sides of a medical device or component thereof may be provided by the second part(s). The top and bottom layers of the medical device or component thereof may be provided by the second part(s). An intermediate layer of the medical device or component thereof may be provided by the second part(s). One or two side portions of the medical device or component thereof may be provided by the second part(s). The majority of the medical device or component thereof may be provided by the second part(s). A plug and/or insert ofthe medical device or component thereof may be provided by the second part(s). One or more flexible members of the medical device or component thereof may be provided by the second part(s). The flexible members may be elongate and/or longitudinally aligned with one another and/or surrounded by an at least partial enclosure.
The first part may include an element embedded therein. The element may be wire and/or band and/or strip. Preferably the element provides the difference in one or more properties. The second part may include an element embedded therein. The element may be wire and/or band and/or strip. Preferably the element provides the difference in one or more properties.
The one or more first parts and one or more second parts are preferably joined together. Preferably an integral unit is formed ofthe first and second parts.
The first part may be substantially opaque to one or more emission types. The first part may be opaque to one or more emission types. The first part may be opaque to x- rays. The second part may be substantially opaque to one or more emission types. The second part may be opaque to one or more emission types. The second part may be opaque to x-rays.
The first part may be different to the second part due to one or more additional materials being present. The additional materials may be present in the first and/or second part. The additional material may be present in one part and absent from the other part. The additional material may be present in one part at one level and present in the other part at a different level. The additional material may be one or more barium containing compounds and/or one or more metals and/or one or more x-ray opaque materials. The additional material may be or include barium sulphate. The additional material may be between lwt% and 50wt% of the part. The additional material may more preferably be between 8wt% and 20wt% ofthe part.
The first part may be different to the second part in terms of its wear resistance and/or stiffness and/or Shore hardness due to one or more additional materials being present. The additional materials may be present in the first and/or second part. The additional material may be present in one part and absent from the other part. The additional material may be present in one part at one level and present in the other part at a different level. The additional material may be one or more barium containing compounds and/or one or more metals and/or one or more x-ray opaque materials. The additional material may be or include barium sulphate. The additional material may be between lwt% and 50wt% of the part. The additional material may more preferably be between 8wt% and 20wt% ofthe part.
Preferably the first part may be different to the second part, in respect of its ability for an emission to pass through and one or more of wear resistance and/or stiffness and/or Shore hardness, due to the same one or more additional materials being present. The same additional material may be present in the first and/or second part. The same additional material may be present in one part and absent from the other part. The same additional material may be present in one part at one level and present in the other part at a different level. The same additional material may be one or more barium containing compounds and/or one or more metals and/or one or more x- ray opaque materials. The same additional material may be or include barium sulphate. The same additional material may be between 1 wt% and 50wt% of the part. The same additional material may more preferably be between 8wt% and 20wt% of the part.
The eighth aspect of the invention may include any of the features, options or possibilities set out elsewhere in this application and in particular in the ninth and/or tenth and/or eleventh aspects ofthe invention. According to a ninth aspect of the invention we provide the use of an additive decrease the ability of emissions to pass through a material and to increase the wear resistance and/or stiffness and/or Shore hardness of a material.
Preferably the ability of emissions to pass through the material refers to the ability of x-rays to pass through the material. Preferably the wear resistance of the material is increased. Preferably the additive is x-ray opaque. Preferably the additive is a barium compound. More preferably the additive includes barium sulphate. Ideally the barium compound is provided at between 8wt% and 20wt% ofthe material.
The ninth aspect of the invention may include any of the features, options or possibilities set out elsewhere in this application and in particular in the eighth and/or tenth and/or eleventh aspects ofthe invention.
The first and second parts are preferably joined together. The first and second parts may be joined together as part ofthe production process, for instance in a mould. The first and second parts may be separate and then joined together. The first and second parts may be formed at the same time, for instance by introducing them at the same time, for instance into the same mould. The first and second parts may be formed by calanderising. One or more first parts may be cut from a large piece. One of more second parts may be cut from a large piece. The pieces may be sheets. The parts may be put together as a series of layers. The first and second parts may alternate in terms of the layers. The first and/or second parts may be uncured. Preferably the first and/or second parts are cured after assembly. The first and second parts may be joined to one another by bonding and/or gluing.
The tenth aspect of the invention may include any of the features, options or possibilities set out elsewhere in this application and in particular in the eighth and/or ninth and/or eleventh aspects ofthe invention.
The eleventh aspect of the invention may include any of the features, options or possibilities set out elsewhere in this application and in particular in the eighth and/or ninth and/or tenth aspects ofthe invention.
Various embodiments of the invention will now be described, by way of example only, and with reference to the accompanying drawings in which:- Figure 1 is an illustration of a first type of prosthesis which can be provided according to the present invention; Figure 2 is an illustration of a second type of prosthesis which can be provided according to the present invention; Figure 3 is an illustration of a set of cores for use in prostheses and provided according to one embodiment ofthe present invention; Figure 4 is an illustration of a set of cores for use in prostheses and provided according to a second embodiment ofthe present invention; Figures 5a to 5f are illustrations of embodiments of the invention which make use of localised variations in properties.
Developments in intervertebral disc replacements include new designs of disc based upon using the deformation of an elastomer to allow motion of the intervertebral joint. Elastomer designs include: Bonded elastomers, see Figure 1, where the elastomer 2 is bonded between rigid or very stiff end-plates 4, 6 that are usually metallic in nature. Encapsulated elastomers, see Figure 2, where the elastomer 8 is surrounded by another material 10, such as a fabric.
This variation in properties is not a true reflection of the variation in properties for natural intervertebral discs with size. As a result, the replacements are not totally accurate mimics ofthe natural discs.
Another embodiment of the approach taken in the present invention is illustrated in Figure 3. A series of different disc sizes are provided, with the surgeon potentially selecting the appropriate size so as to mimic the size of natural disc being replaced. As well as mimicking size, however, the invention also provides that the elastomer used in each different size has a different Shore hardness. This allows the intended stiffness and/or shock absorbing properties to be provided in each disc size and so provides for full mimicking of the natural disc in each size. Rather than taking the prior art approach of scaling the size and living with the consequences in terms of the structural properties which result, the present invention also provides for careful selection ofthe material so as to provide the desired properties too.
In the series shown in Figure 3, there are four different sizes, A, B, C and D, each larger than the last in cross-sectional area (shown) and depth (not shown). Of course, the variation between discs may be in respect of one or more size factors. Four different Shore hardness elastomers are used, a for A, b for B, c for C and d for D. The elastomer is basically the same general type of elastomer in each case.
In the embodiment of the invention illustrated in Figure 4, the concept is expanded further. Here the series includes a first set of four different sizes Al, Bl, CI and Dl and a second set of four sizes, each matching to one size in the first set, the sizes being A2, B2, C2 and D2. The first set is intended for a first type of situation requiring disc replacement and the second set is intended for a second type of situation requiring disc replacement. The different situation may be a different medical condition and/or different type of patient and/or, as in this embodiment, a different build of patient. Thus for the first set, intended perhaps for patients of larger build, the Shore hardness is greater for the same size of disc than the Shore harness of the second set. Disc Al is harder than disc A2, disc Bl is harder than disc B2 and so on to reflect the greater loads to be accommodated. Within the sets the Shore hardness varies between the different sizes too. Thus Dl is softer than CI, is softer in turn than Bl, is softer in turn than Al . The second set is intended for a lighter build of patient.
A further difference in the Figure 4 embodiment is the manner in which the elastomer is formed. In this case, the elastomer provides an outer X which contains a filler Y. Embodiments in which the filler Y is distributed, preferably as evenly "as possible, throughout the elastomer may be provided. Different filler types and/or concentrations of filler are used in this embodiment to vary the Shore hardness.
As well enabling the correct size and properties for a medical implant so as to suit a wide variety of people, the present invention also achieves other benefits through the use of carefully selected additives and structures for implants. After, and even potentially during surgery, it is helpful to be able to establish the position of an implant accurately. The applicant has added material to the elastomer which forms an implant, during its production, to make it visible to x-ray inspection. One way to do so is mix in barium compounds, such as barium sulphate. A loading of 13% by weight represents an example of this approach. The barium sulphate is thus distributed throughout the elastomer and does make the implant visible on x-ray images.
When forming the implant in a mould, it is also possible to provide two separate injection nozzles with one introducing the material to form one part of the implant and the other introducing material to form another part of the implant. One of the nozzles provides the material with the x-ray opaque material in it. The materials may only differ from one another in terms of the x-ray opaque material or may have other differences. Calanderising is another possible production technique. Different parts of the eventual implant are cut out of blocks or sheets of different materials. The materials differ from one another at least in terms of one possessing the x-ray opaque material. The different parts are put together as a series of layers of uncured elastomer and then joined together, for instance in a mould. Thus opaque and non-opaque layers could be alternated, for instance.
The provision of implants and the like which have limited and/or localised radioopacity and/or radiolucency and/or limited and/or localised strength and/or limited or localised stiffness offers many advantages and possibilities. It should also be noted, that the material added to localities within the implant or other item could be used to modify the appearance of the implant/item to other imaging approaches. Alterations to render localities on the implant highly visible to MRI and other imaging approaches are possible.
By way of example, some possible structures with localised x-ray opaque material are shown in Figure 5 a through Figure 5f. In Figure 5a, a part with x-ray opaque material 2 is sandwiched between two parts 4 which are free of x-ray opaque material. The parts 2, 4 are joined to one another to form an integral implant. In Figure 5b, a part 6 which includes x-ray opaque material is shown between parts 8 which are x-ray opaque material free. The non-parallel faces of the parts 8 reflect overall configurations encountered in spinal implants. In Figure 5c, the x-ray opaque material is restricted to one face 10 of the implant, with the other part 12 being x-ray opaque material free. Such a set up is particularly useful for clearly indicating the posterior and/or anterior edge of the implant when inserted. In Figure 5d, both the posterior edge 14 and anterior edge 16 are shown with x-ray opaque material, whilst the middle of the implant, part 18, is x-ray opaque material free. This approach allows good judgement of the position of the implant, when viewed from the side of the patient. The side view is the most readily used view in an x-ray. This approach also means that the amount of the image rendered opaque by the x-ray opaque material is minimised; the image will show two lines, with transparent material between. In Figure 5e, a small plug 20 of x-ray opaque material is provided in a larger part 22 which is x-ray opaque material free. Many possibilities are present for the localised x-ray opaque material. Finally in Figure 5f, some of the many parts 24 aligned with one another within a sleeve 26 are provided with x-ray opaque material and other parts 28 are not.
1. A series of disc prostheses, the series including at least a first prosthesis and a second prosthesis, the first prosthesis differing in size and differing in one or more materials from which it is formed compared with the second prosthesis, the first and second prostheses being ofthe same type.
2. A series according to claim 1 in which the prostheses differ in size from one another so as to approximate to the size ofthe natural intervertebral disc they are intended to replace.
3. A series according to claim 1 or claim 2 in which the first prosthesis and second prosthesis differ in material so as to control one or more structural properties ofthe prosthesis.
4. A series according to claim 3 in which the one or more structural properties are controlled so as to approximate to the properties ofthe particular disc being replaced.
5. A series according to claim 3 or claim 4 in which the one or more structural properties include the compressional and/or axial stiffness.
6. A series according to any of claims 3 to 5 in which the one or more structural properties include the flexion extension stiffness.
7. A series according to any preceding claim in which the series is divided into two or more sets of prostheses, each of which includes a first prosthesis and a second prosthesis, at least the first prostheses ofthe two or more sets being the same size but differing in terms of one or more of their structural properties.
8. A series according to claim 7 in which the different sets of prostheses are intended for different uses, for instance to address different medical conditions and/or medical procedures and/or different patients.
9. A series according to any preceding claim in which the material differs due to the material used to form it and/or the grade of material used to form it and/or due to one or more additives and/or the level thereof.
10. A series according to any preceding claim in which the material differs due to the treatment ofthe material before and/or during and/or after production.
11. A method for producing disc prostheses, the method including forming disc prostheses of a first kind and forming disc prostheses of a second kind, the first prosthesis kind differing in size and differing in one or more materials from which it is formed compared with the second prosthesis kind, the first and second prostheses being ofthe same type.
12. A method according to claim 11 in which the material ofthe first prosthesis and/or second prosthesis is chosen to provide one or more structural properties matched to a particular disc in a human spine and/or of a particular person.
13. A surgical method for provide a disc prosthesis, the method including removing at least a part ofthe natural disc in a spine and inserting a disc prosthesis in the spine, the disc prosthesis being selected from a series of disc prostheses, the series including at least a first prosthesis and a second prosthesis, the first prosthesis differing in size and differing in one or more materials from which it is formed compared with the second prosthesis, the first and second prostheses being ofthe same type.
15. A device according to claim 14 in which the second part differs from the first part in terms of a lower wear resistance and/or stiffness and/or Shore hardness compared with the first part.
16. A device according to claim 14 in which the second part differs from the first part in terms of a higher wear resistance and/or stiffness and/or Shore hardness compared with the first part.
17. A device according to any of claims 14 to 16 in which the first part includes an element embedded therein, with the element providing the difference in one or more properties compared with the second part.
18. A device according to any of claims 14 to 17 in which the second part includes an element embedded therein, with the element providing the difference in one or more properties compared with the first part.
19. A device according to any of claims 14 to 18 in which the second part differs from the first part in terms of a lower ability of an emission to pass through the second part compared with the first part or the second part differs from the first part in terms of a higher ability of an emission to pass through the second part compared with the first.
20. A device according to claim 19 in which the emission are radiowaves and/or x- rays and/or gamma rays and/or the emissions arise as a result of magnetic resonance imaging and/or the emissions arise as a result ofthe application of a magnetic field and/or radiowaves to the body.
21. A device according to any of claims 14 to 20 in which the first part is different to the second part due to one or more additional materials being present in the first and/or second part.
22. A device according to claim 21 in which the additional material is one or more barium containing compounds and/or one or more metals and/or one or more x-ray opaque materials.
23. A device according to any of claims 14 to 22 in which the top surface and/or bottom surface of a medical device or a component thereof are provided by the first part(s).
24. A device according to any of claims 14 to 23 in which an intermediate layer of the medical device or component thereof is provided by the first part(s).
25. A device according to any of claims 14 to 24 in which one or two side portions of the medical device or component thereof are provided by the first part(s).
26. The use of an additive to decrease the ability of emissions to pass through a material and to increase the wear resistance and/or stiffness and/or Shore hardness of the material.
27. The use of claim 26 in which the ability of emissions to pass through the material refers to the ability of x-rays to pass through the material.
28. The use of claim 26 or claim 27 in which the wear resistance ofthe material is increased.
29. The use of any of claims 26 to 28 in which the additive is a barium compound.
31. A method in which a medical device is provided in a body, the device including a first part and a second part, the first part having a first set of properties, the second part differing from the first part with respect to one or more of those properties and one or more ofthe properties are investigated.
PCT/GB2005/001967 2004-05-20 2005-05-20 Improvements in and relating to surgical implants WO2005112833A1 (en)
US11/597,161 US20080269900A1 (en) 2004-05-20 2005-05-20 Surgical Implants
US13/107,557 US20110218632A1 (en) 2004-05-20 2011-05-13 Surgical implants
US13/107,557 Continuation US20110218632A1 (en) 2004-05-20 2011-05-13 Surgical implants
WO2005112833A1 true WO2005112833A1 (en) 2005-12-01
WO2007089960A2 (en) * 2006-01-31 2007-08-09 Warsaw Orthopedic, Inc. Intervertebral spinal implant devices and methods of use
US20110004313A1 (en) * 2007-08-09 2011-01-06 Spinalmotion, Inc. Customized Intervertebral Prosthetic Disc With Shock Absorption
EP1318167A2 (en) * 2001-12-07 2003-06-11 MERCK PATENT GmbH Polymer based material containing silica particles
WO2003068111A1 (en) * 2002-02-13 2003-08-21 Danfoss A/S Implant for spine and method for manufacturing same
WO2003077806A1 (en) * 2002-03-15 2003-09-25 Fixano Dynamic intervertebral implant
DE3931772A1 (en) * 1989-09-23 1991-04-04 Bayer Ag Thermoplastic molding compositions consisting of polyalkylene terephthalate, special barium sulfate, particulate graft polymers and optionally verstaerkungsmitteln
2005-05-20 WO PCT/GB2005/001967 patent/WO2005112833A1/en active Application Filing
2005-05-20 US US11/597,161 patent/US20080269900A1/en not_active Abandoned
2011-05-13 US US13/107,557 patent/US20110218632A1/en not_active Abandoned
WO2007089960A3 (en) * 2006-01-31 2007-09-20 Eric S Heinz Intervertebral spinal implant devices and methods of use
US8506631B2 (en) * 2007-08-09 2013-08-13 Spinalmotion, Inc. Customized intervertebral prosthetic disc with shock absorption
US20080269900A1 (en) 2008-10-30
US20110218632A1 (en) 2011-09-08
JP5215999B2 (en) 2013-06-19 Surgical spacer having a shape control function
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