CA2011724C - Orthopaedic implant - Google Patents
Orthopaedic implant Download PDFInfo
- Publication number
- CA2011724C CA2011724C CA002011724A CA2011724A CA2011724C CA 2011724 C CA2011724 C CA 2011724C CA 002011724 A CA002011724 A CA 002011724A CA 2011724 A CA2011724 A CA 2011724A CA 2011724 C CA2011724 C CA 2011724C
- Authority
- CA
- Canada
- Prior art keywords
- fibres
- polymer
- bearing surface
- component
- layers
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
- 239000007943 implant Substances 0.000 title claims description 8
- 239000000835 fiber Substances 0.000 claims abstract description 35
- 229920000642 polymer Polymers 0.000 claims abstract description 33
- 210000002303 tibia Anatomy 0.000 claims description 11
- 239000004698 Polyethylene Substances 0.000 claims description 5
- 238000000034 method Methods 0.000 claims description 5
- -1 polyethylene Polymers 0.000 claims description 5
- 229920000573 polyethylene Polymers 0.000 claims description 5
- 238000011882 arthroplasty Methods 0.000 claims description 2
- 210000003127 knee Anatomy 0.000 claims description 2
- 238000007596 consolidation process Methods 0.000 abstract description 6
- 229920005594 polymer fiber Polymers 0.000 abstract description 5
- 210000000629 knee joint Anatomy 0.000 description 6
- 239000004744 fabric Substances 0.000 description 5
- 239000002184 metal Substances 0.000 description 4
- 238000001228 spectrum Methods 0.000 description 4
- 230000006835 compression Effects 0.000 description 3
- 238000007906 compression Methods 0.000 description 3
- 238000000748 compression moulding Methods 0.000 description 3
- 210000000988 bone and bone Anatomy 0.000 description 2
- 210000001624 hip Anatomy 0.000 description 2
- 210000000689 upper leg Anatomy 0.000 description 2
- 208000032538 Depersonalisation Diseases 0.000 description 1
- 229920010741 Ultra High Molecular Weight Polyethylene (UHMWPE) Polymers 0.000 description 1
- 239000004699 Ultra-high molecular weight polyethylene Substances 0.000 description 1
- 238000002441 X-ray diffraction Methods 0.000 description 1
- 210000000588 acetabulum Anatomy 0.000 description 1
- 238000000149 argon plasma sintering Methods 0.000 description 1
- 239000002639 bone cement Substances 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 238000001125 extrusion Methods 0.000 description 1
- 230000004927 fusion Effects 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 238000003754 machining Methods 0.000 description 1
- 239000007769 metal material Substances 0.000 description 1
- 238000001907 polarising light microscopy Methods 0.000 description 1
- 239000002861 polymer material Substances 0.000 description 1
- 239000000843 powder Substances 0.000 description 1
- 230000000717 retained effect Effects 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
- 210000001519 tissue Anatomy 0.000 description 1
- 238000011883 total knee arthroplasty Methods 0.000 description 1
- 229920000785 ultra high molecular weight polyethylene Polymers 0.000 description 1
- 230000000007 visual effect Effects 0.000 description 1
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
- A61F2/38—Joints for elbows or knees
- A61F2/389—Tibial components
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61F—FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
- A61F2/00—Filters implantable into blood vessels; Prostheses, i.e. artificial substitutes or replacements for parts of the body; Appliances for connecting them with the body; Devices providing patency to, or preventing collapsing of, tubular structures of the body, e.g. stents
- A61F2/02—Prostheses implantable into the body
- A61F2/30—Joints
- A61F2/3094—Designing or manufacturing processes
- A61F2/30965—Reinforcing the prosthesis by embedding particles or fibres during moulding or dipping
Landscapes
- Health & Medical Sciences (AREA)
- Engineering & Computer Science (AREA)
- Orthopedic Medicine & Surgery (AREA)
- Heart & Thoracic Surgery (AREA)
- Life Sciences & Earth Sciences (AREA)
- Transplantation (AREA)
- Cardiology (AREA)
- Biomedical Technology (AREA)
- Veterinary Medicine (AREA)
- Vascular Medicine (AREA)
- Oral & Maxillofacial Surgery (AREA)
- Animal Behavior & Ethology (AREA)
- General Health & Medical Sciences (AREA)
- Public Health (AREA)
- Physical Education & Sports Medicine (AREA)
- Manufacturing & Machinery (AREA)
- Prostheses (AREA)
Abstract
A plurality of polymer layers are stacked together and subjected to a consolidation operation to generate an orthopaedic bearing component. Each layer is formed by longitudinally extending polymer fibers that are placed or woven together to define a predetermined orientation of the fibers.
The consolidation operation fuses the layers together while at the same time retaining the predetermined orientation of the fibers.
The consolidation operation fuses the layers together while at the same time retaining the predetermined orientation of the fibers.
Description
ORTHOPAEDIC IMPLANT
The present invention relates to an orthopaedic implant to be used in surgical repair and/or reconstruction of human joints. In particular the invention is concerned with a unique construction for a tibia bearing plate for use in total knee arthroplasty, and, in the alternative, other bearing components in orthopaedic implants.
It has been the practice for many years in knee arthroplasty to reconstruct knee joints by attaching a femoral component to the distal end of a femur and attaching a tibial component to the proximal end of a tibia. The tibia component retains a bearing plate with an articulating surface forming a sliding engagement with the femoral component. Heretofore, the bearing plate was constructed from polymer flakes or polymer powder that were compression molded to the desired geometry of the bearing plate. In addition, it was possible to machine a block of molded or extruded polymer to the desired geometry. With polymer flakes, the polymer molecules are orientated in a random fashion such that some molecules extend in the direction of sliding motion between the femoral component and the bearing plate while other molecules intersect the articulating surface in a direction normal to the sliding direction. It is believed that the orientation of the molecules in a direction normal to the sliding direction creates resistance to sliding movement and such resistance results in wear debris in response to sliding movement of the femoral component relative to the bearing plate.
The invention in one aspect includes an orthopaedic bearing component uniformly composed of a single polymer and defining an articular bearing surface wherein the polymer comprises consolidated fibres, the molecules of which are oriented in the lengthwise direction of said fibres, the majority of S fibres at said bearing surface of the bearing component being oriented substantially parallel to one another so that intersecting fibres are substantially eliminated at said bearing surface, said majority of the fibres also being orientated substantially parallel to the intended direction of articulation.
An embodiment of the present invention provides for a predetermined orientation of polymer fibers in a tibial bearing plate such that the predetermined orientation substantially parallels sliding movement direction in a knee joint. The predetermined - la-~t~~tl~~, orientation is controlled by using longitudinally extending polymer fibers that are woven or arranged into layers and each fiber is formed with molecules extending in the longitudinal direction. In a preferred embodiment, a multiplicity of the layers are stacked on top of each other in a laminated manner with the fibers of each woven layer orientated in a predetermined direction. Thereafter, consolidation tightly binds the layers together and a die utilized during or after consolidation imparts a contoured outer surface to the final structure. In particular a tibial bearing plate is formed by stacking together a plurality of layered ultra high molecular weight polyethylene (UHMWPE) ~ fibers. In the preferred embodiment, each layer is formed with a fine weave and the UHMWPE is preferably Spectra 900 as marketed by the Allied Signal Corporation. The consolidation process preferably includes compression molding but it is also possible to utilize pultrusion, isostatic compression or extrusion to consolidate the fibers.
In an alternative embodiment of the present invention the tibial bearing plate is formed from a combination of polymer flake, and/or chopped polymer fibers with layers of woven longitudinally extending fibers. The layers are compression molded to the chopped fibers and/or polymer flake such that the articulating surface of the tibial bearing plate is formed by the layers of longitudinally extending fibers and the chopped fibers and/or polymer flake are provided to "back-up'~ the layered longitudinally extending fibers and remain spaced from the articulating surface.
It is an advantage of the present invention that the tibial bearing plate is formed from longitudinal fibers that retain molecular orientation in the longitudinal direction following 20~~. r ~;<~
compression molding. Therefore, the fiber molecules are orientated in a plane substantially parallel to the interface between the femoral component and the bearing plate and resistance to movement at the interface is reduced. With less resistance it is believed that wear debris will also be reduced to minimize the release of debris into the tissue surrounding the reconstructed knee joint.
In the drawings Fig. 1 shows a frontal cross sectional view of a knee joint schematically illustrating the tibial bearing plate of the present invention. Fig. 2 is a top view of the tibial bearing plate and tibial tray shown in Fig. 1. Fig. 3 is a cross sectional view taken along line 3-3 of Fig. 1. Fig. 4 is a schematic illustration of the process utilized to construct the tibial bearing plate of the present invention. Fig. 5 is a view- similar to Fig. 3 showing an alternative embodiment of the present invention.
A knee joint prosthesis 10 in Fig. 1 includes a femoral component 12 made from metallic material and a tibial component 14 comprising a metal tray 16 and a tibial bearing plate 18.
The femoral component 12 is secured to the distal femur of a patient receiving the knee joint prosthesis by any suitable means such as bone cement or bone ingrowth via a porous surface on the side of the component in intimate contact with the bone.
In a similar fashion the tibial component 14 is secured to the proximal tibia by any suitable means so that the tibial tray 16 is secured to the tibia. Optional pegs 20 can be provided to enhance fixation to the tibia.
The tibial tray 16 includes a circumferential rim 22 cooperating with a bottom surface 24 to form a recess 26. The tibial bearing plate 18 fits within the recess 26 and is secured to the tibia tray via suitable means to prevent separation therebetween. If a modular tibial component is desired it is also possible to modify the tibial tray 16 so that different sizes of tibial bearing plates may be secured to the tibial tray in response to different sizes of femoral components 12. The superior contour of the tibial bearing plate includes arcuate depressions 28 and 30 which slidingly engage the arcuate condylar portions 32 and 34, respectively, of the femoral component 12.
In order to form the tibial bearing plate 18, a plurality of longitudinally extending fibers are woven into a cloth layer 40 (Fig. 4) such that the fiber orientation is maintained by the weave pattern and each individual fiber 36 extends across the width or length of the layer 40. As shown in Fig. 2, the fibers 36 extend in a lateral=medial direction and in an anterior-posterior direction. The length and width dimension for each layer is approximately equal to the maximum length and width dimension for the tibial bearing plate 18. A plurality of layers 40 are stacked on top of each other as shown in Fig. 4 between a die 42 and a jig 44. The die 42 includes an outer surface 46 identical in contour to the contour of the arcuate depressions 28 and 30 so that when the die 42 is forced against the plurality of layers 40 the arcuate depressions 28 and 30 will be imparted to, the piece removed from the jig. When the die 42 is impacted against the layers 40 in a compression molding operation, the jig 44 and die 42 are suitably equipped with heating elements to heat the fibers to a temperature that permits fusion and consolidation of all the fibers without a loss of identity for most of the discrete fibers. After the die imparts a contour to the plurality of heated layers 40, the tibial plate 18 is formed as a rigid structure from the plurality of layers 40. The tibial bearing plate 18 is then ~~U~.17~L:~
removed from the jig 44 for final cutting and machining to remove burrs and/or impart the final geometry to the tibial bearing plate 18 before utilization with the tibial tray 14.
A tibial bearing plate 18 constructed in accordance with the aforegoing procedure retains evidence of a substantial number of individual fibers within the rigid structure so that it is possible to identify a weave or orientation pattern in the tibial bearing plate 18. It is contemplated that such identification may include visual examination, light scattering techniques, x-ray diffraction or polarized light microscopy. A
suitable fiber for constructing the tibial bearing plate 18 is Spectra 900 polyethylene (Allied Signal Corporation) with a density of .97 grams per cubic centimeter and a fiber diameter equal to 38 microns. As an alternative, it is possible to construct the tibial bearing plate 18 from Spectra 1000 polyethylene (Allied Signal Corporation) with a density of .97 grams per cubic centimeter and a fiber diameter of 20-25 microns. Each layer of fiber cloth 40 is also available from Allied Signal Corporation in cloth form as Spectra 900 Plain Weave S902 Scoured cloth.
In the alternative embodiment of Fig. 5, the tibial bearing plate 118 includes a plurality of woven layers 140 of longitudinally extending fibers at the articulating surface 128. A first region 102 is made from the longitudinally extending fibers and a second region 104 is made from chopped polymer fibers and/or polymer flake 106. The depth of the first region 102 is less than the depth of the second region so that only the region of the tibial bearing plate immediately adjacent the articulating surface 128 is provided with the woven layers of longitudinally extending fibers.
I~ ~ .~ A'~~~~.r S
Although the aforegoing description proceeds with reference to a tibial bearing plate, it is within the scope of the appended claims to construct other polymer bearing components in accordance with the present invention. For example, an acetabular cup prosthesis includes a metal shell for attachment to an acetabulum and a polymer bearing retained within the metal shell for articulating engagement with the head of a hip prosthesis. This polymer bearing can be formed from a plurality of polymer longitudinally extending fibers in cloth layer form with a corresponding jig and die to generate the appropriate contour for cooperation with the metal shell and hip prosthesis.
In addition, other polymers may be used in place of polyethylene so long as the polymer material is available in fiber form.
The present invention relates to an orthopaedic implant to be used in surgical repair and/or reconstruction of human joints. In particular the invention is concerned with a unique construction for a tibia bearing plate for use in total knee arthroplasty, and, in the alternative, other bearing components in orthopaedic implants.
It has been the practice for many years in knee arthroplasty to reconstruct knee joints by attaching a femoral component to the distal end of a femur and attaching a tibial component to the proximal end of a tibia. The tibia component retains a bearing plate with an articulating surface forming a sliding engagement with the femoral component. Heretofore, the bearing plate was constructed from polymer flakes or polymer powder that were compression molded to the desired geometry of the bearing plate. In addition, it was possible to machine a block of molded or extruded polymer to the desired geometry. With polymer flakes, the polymer molecules are orientated in a random fashion such that some molecules extend in the direction of sliding motion between the femoral component and the bearing plate while other molecules intersect the articulating surface in a direction normal to the sliding direction. It is believed that the orientation of the molecules in a direction normal to the sliding direction creates resistance to sliding movement and such resistance results in wear debris in response to sliding movement of the femoral component relative to the bearing plate.
The invention in one aspect includes an orthopaedic bearing component uniformly composed of a single polymer and defining an articular bearing surface wherein the polymer comprises consolidated fibres, the molecules of which are oriented in the lengthwise direction of said fibres, the majority of S fibres at said bearing surface of the bearing component being oriented substantially parallel to one another so that intersecting fibres are substantially eliminated at said bearing surface, said majority of the fibres also being orientated substantially parallel to the intended direction of articulation.
An embodiment of the present invention provides for a predetermined orientation of polymer fibers in a tibial bearing plate such that the predetermined orientation substantially parallels sliding movement direction in a knee joint. The predetermined - la-~t~~tl~~, orientation is controlled by using longitudinally extending polymer fibers that are woven or arranged into layers and each fiber is formed with molecules extending in the longitudinal direction. In a preferred embodiment, a multiplicity of the layers are stacked on top of each other in a laminated manner with the fibers of each woven layer orientated in a predetermined direction. Thereafter, consolidation tightly binds the layers together and a die utilized during or after consolidation imparts a contoured outer surface to the final structure. In particular a tibial bearing plate is formed by stacking together a plurality of layered ultra high molecular weight polyethylene (UHMWPE) ~ fibers. In the preferred embodiment, each layer is formed with a fine weave and the UHMWPE is preferably Spectra 900 as marketed by the Allied Signal Corporation. The consolidation process preferably includes compression molding but it is also possible to utilize pultrusion, isostatic compression or extrusion to consolidate the fibers.
In an alternative embodiment of the present invention the tibial bearing plate is formed from a combination of polymer flake, and/or chopped polymer fibers with layers of woven longitudinally extending fibers. The layers are compression molded to the chopped fibers and/or polymer flake such that the articulating surface of the tibial bearing plate is formed by the layers of longitudinally extending fibers and the chopped fibers and/or polymer flake are provided to "back-up'~ the layered longitudinally extending fibers and remain spaced from the articulating surface.
It is an advantage of the present invention that the tibial bearing plate is formed from longitudinal fibers that retain molecular orientation in the longitudinal direction following 20~~. r ~;<~
compression molding. Therefore, the fiber molecules are orientated in a plane substantially parallel to the interface between the femoral component and the bearing plate and resistance to movement at the interface is reduced. With less resistance it is believed that wear debris will also be reduced to minimize the release of debris into the tissue surrounding the reconstructed knee joint.
In the drawings Fig. 1 shows a frontal cross sectional view of a knee joint schematically illustrating the tibial bearing plate of the present invention. Fig. 2 is a top view of the tibial bearing plate and tibial tray shown in Fig. 1. Fig. 3 is a cross sectional view taken along line 3-3 of Fig. 1. Fig. 4 is a schematic illustration of the process utilized to construct the tibial bearing plate of the present invention. Fig. 5 is a view- similar to Fig. 3 showing an alternative embodiment of the present invention.
A knee joint prosthesis 10 in Fig. 1 includes a femoral component 12 made from metallic material and a tibial component 14 comprising a metal tray 16 and a tibial bearing plate 18.
The femoral component 12 is secured to the distal femur of a patient receiving the knee joint prosthesis by any suitable means such as bone cement or bone ingrowth via a porous surface on the side of the component in intimate contact with the bone.
In a similar fashion the tibial component 14 is secured to the proximal tibia by any suitable means so that the tibial tray 16 is secured to the tibia. Optional pegs 20 can be provided to enhance fixation to the tibia.
The tibial tray 16 includes a circumferential rim 22 cooperating with a bottom surface 24 to form a recess 26. The tibial bearing plate 18 fits within the recess 26 and is secured to the tibia tray via suitable means to prevent separation therebetween. If a modular tibial component is desired it is also possible to modify the tibial tray 16 so that different sizes of tibial bearing plates may be secured to the tibial tray in response to different sizes of femoral components 12. The superior contour of the tibial bearing plate includes arcuate depressions 28 and 30 which slidingly engage the arcuate condylar portions 32 and 34, respectively, of the femoral component 12.
In order to form the tibial bearing plate 18, a plurality of longitudinally extending fibers are woven into a cloth layer 40 (Fig. 4) such that the fiber orientation is maintained by the weave pattern and each individual fiber 36 extends across the width or length of the layer 40. As shown in Fig. 2, the fibers 36 extend in a lateral=medial direction and in an anterior-posterior direction. The length and width dimension for each layer is approximately equal to the maximum length and width dimension for the tibial bearing plate 18. A plurality of layers 40 are stacked on top of each other as shown in Fig. 4 between a die 42 and a jig 44. The die 42 includes an outer surface 46 identical in contour to the contour of the arcuate depressions 28 and 30 so that when the die 42 is forced against the plurality of layers 40 the arcuate depressions 28 and 30 will be imparted to, the piece removed from the jig. When the die 42 is impacted against the layers 40 in a compression molding operation, the jig 44 and die 42 are suitably equipped with heating elements to heat the fibers to a temperature that permits fusion and consolidation of all the fibers without a loss of identity for most of the discrete fibers. After the die imparts a contour to the plurality of heated layers 40, the tibial plate 18 is formed as a rigid structure from the plurality of layers 40. The tibial bearing plate 18 is then ~~U~.17~L:~
removed from the jig 44 for final cutting and machining to remove burrs and/or impart the final geometry to the tibial bearing plate 18 before utilization with the tibial tray 14.
A tibial bearing plate 18 constructed in accordance with the aforegoing procedure retains evidence of a substantial number of individual fibers within the rigid structure so that it is possible to identify a weave or orientation pattern in the tibial bearing plate 18. It is contemplated that such identification may include visual examination, light scattering techniques, x-ray diffraction or polarized light microscopy. A
suitable fiber for constructing the tibial bearing plate 18 is Spectra 900 polyethylene (Allied Signal Corporation) with a density of .97 grams per cubic centimeter and a fiber diameter equal to 38 microns. As an alternative, it is possible to construct the tibial bearing plate 18 from Spectra 1000 polyethylene (Allied Signal Corporation) with a density of .97 grams per cubic centimeter and a fiber diameter of 20-25 microns. Each layer of fiber cloth 40 is also available from Allied Signal Corporation in cloth form as Spectra 900 Plain Weave S902 Scoured cloth.
In the alternative embodiment of Fig. 5, the tibial bearing plate 118 includes a plurality of woven layers 140 of longitudinally extending fibers at the articulating surface 128. A first region 102 is made from the longitudinally extending fibers and a second region 104 is made from chopped polymer fibers and/or polymer flake 106. The depth of the first region 102 is less than the depth of the second region so that only the region of the tibial bearing plate immediately adjacent the articulating surface 128 is provided with the woven layers of longitudinally extending fibers.
I~ ~ .~ A'~~~~.r S
Although the aforegoing description proceeds with reference to a tibial bearing plate, it is within the scope of the appended claims to construct other polymer bearing components in accordance with the present invention. For example, an acetabular cup prosthesis includes a metal shell for attachment to an acetabulum and a polymer bearing retained within the metal shell for articulating engagement with the head of a hip prosthesis. This polymer bearing can be formed from a plurality of polymer longitudinally extending fibers in cloth layer form with a corresponding jig and die to generate the appropriate contour for cooperation with the metal shell and hip prosthesis.
In addition, other polymers may be used in place of polyethylene so long as the polymer material is available in fiber form.
Claims (14)
1. An orthopaedic bearing component uniformly composed of a single polymer and defining an articular bearing surface wherein the polymer comprises consolidated fibres, the molecules of which are oriented in the lengthwise direction of said fibres, the majority of fibres at said bearing surface of the bearing component being oriented substantially parallel to one another so that intersecting fibres are substantially eliminated at said bearing surface, said majority of the fibres also being orientated substantially parallel to the intended direction of articulation.
2. The component of claim 1 in which the fibres include a plurality of layers stacked on top of each other to form the bearing surface.
3. The component of claim 1 or 2 in which the polymer comprises polyethylene fibres.
4. The component of any one of claims 1-3 in which individual discrete fibres are arranged together to form a tibial component for knee arthroplasty.
5. The component of claim 1 in which the fibre arrangement is a weave pattern.
6. A method for constructing a tibial component defining an articular bearing surface comprising the steps of arranging a plurality of fibres composed of a single polymer to form a multiplicity of fibre layers, the molecules of said fibres being oriented in the lengthwise direction thereof; and consolidating the multiplicity of fibre layers together sufficiently to fuse the fibres together while retaining the molecular orientation thereof, the fibres further being arranged such that the fibres at said bearing surface are oriented substantially parallel to one another and to the intended direction of articulation and so that intersecting fibres are substantially eliminated at the bearing surface.
7. The method of claim 6 in which the multiplicity of fibre layers is at least equal to twenty or more layers before said consolidating step.
8. A polymer tibia bearing plate having an articular bearing surface adapted for sliding engagement with a femoral component, the polymer tibia bearing plate comprising a laminated structure with a multiplicity of single-polymer fibre layers joined together wherein the polymer comprises consolidated fibres, the molecules of which are linearly oriented, the majority of fibres at said bearing surface being oriented substantially parallel to one another and to the intended direction of articulation so that intersecting fibres are substantially eliminated at said bearing surface.
9. The polymer tibia bearing plate of claim 8 in which the majority of the fibres at said bearing surface are substantially parallel to the bearing surface.
10. The polymer tibia bearing plate of claim 9 in which the polymer comprises polyethylene fibres substantially parallel to the bearing surface.
11. An orthopaedic implant component defining a rigid bearing surface comprising a plurality of longitudinally extending single-polymer fibres, the molecules of which are linearly oriented, said fibres also being oriented substantially parallel to one another so that intersecting fibres are substantially absent from the rigid bearing surface and so that a majaority of the fibres at the bearing surface extend parallel to the intended direction of articulation with other forms of the polymer being remote from the rigid bearing surface, and the other forms of the polymer being fused together with the longitudinally extending fibres to form a rigid structure for the component.
12. The orthopaedic implant of claim 11 in which the plurality of longitudinally extending fibres occupy less volume of the component than the other forms.
13. The orthopaedic implant of claim 11 in which the plurality of longitudinally extending fibres are arranged together to form individual layers of longitudinally extending fibres and the layers are fused together.
14. The orthopaedic implant of claim 11 in which one of the other forms of the polymer is polymer flake.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US32104989A | 1989-03-09 | 1989-03-09 | |
| US321,049 | 1989-03-09 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CA2011724A1 CA2011724A1 (en) | 1990-09-09 |
| CA2011724C true CA2011724C (en) | 2000-05-30 |
Family
ID=23248964
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002011724A Expired - Lifetime CA2011724C (en) | 1989-03-09 | 1990-03-08 | Orthopaedic implant |
Country Status (9)
| Country | Link |
|---|---|
| JP (1) | JP3103088B2 (en) |
| AU (1) | AU632095B2 (en) |
| CA (1) | CA2011724C (en) |
| CH (1) | CH686341A5 (en) |
| DE (1) | DE4006714B4 (en) |
| ES (1) | ES2021966A6 (en) |
| FR (1) | FR2644057A1 (en) |
| GB (1) | GB2231800B (en) |
| IT (1) | IT1241681B (en) |
Families Citing this family (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5609638A (en) * | 1994-11-29 | 1997-03-11 | Zimmer, Inc. | Reinforced polyethylene for articular surfaces |
| GB9522478D0 (en) * | 1995-11-02 | 1996-01-03 | Howmedica | Prosthetic bearing element and implant incorporating such an element |
| DE29615920U1 (en) * | 1996-09-12 | 1998-01-15 | Waldemar Link GmbH & Co, 22339 Hamburg | Joint endoprosthesis |
| US6258126B1 (en) * | 1997-09-09 | 2001-07-10 | Depuy Orthopaedics, Inc. | Cushioned joint prosthesis |
| CA2366822C (en) * | 1999-04-02 | 2008-01-29 | Barry M. Fell | Surgically implantable knee prosthesis |
| DE10021697A1 (en) * | 2000-05-04 | 2001-12-06 | Plus Endoprothetik Ag Rotkreuz | Endoprosthesis socket and method for its production |
| DE10051438B4 (en) * | 2000-10-17 | 2006-11-09 | Tutech Innovation Gmbh | Tibial component of a knee endoprosthesis with a three-dimensional fiber-reinforced structure and method of manufacture |
| GB2408938B (en) * | 2003-12-12 | 2006-05-10 | Roozbeh Shirandami | Improved bearing component of sandwich construction with layered stiffness for use in joint prosthesis |
| DE202004003133U1 (en) | 2004-02-26 | 2004-07-29 | Aap Implantate Ag | Joint replacement tibial plateau |
| WO2010019807A1 (en) * | 2008-08-13 | 2010-02-18 | Smed-Ta/Td, Llc | Orthopaedic implant with spatially varying porosity |
| WO2010043620A1 (en) * | 2008-10-17 | 2010-04-22 | Dsm Ip Assets B.V. | Medical product comprising ultrahigh molecular weight polyethylene |
Family Cites Families (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4209480A (en) * | 1972-10-24 | 1980-06-24 | Homsy Charles A | Implantable material and method of preparing same |
| US4055862A (en) * | 1976-01-23 | 1977-11-01 | Zimmer Usa, Inc. | Human body implant of graphitic carbon fiber reinforced ultra-high molecular weight polyethylene |
| DE2603456C2 (en) * | 1976-01-30 | 1984-04-05 | Robert Bosch Gmbh, 7000 Stuttgart | Process for the production of a bone implant |
| US4195368A (en) * | 1978-01-09 | 1980-04-01 | Networks Electronic Corp. | Surgical repair pad for disease-damaged joints and method of implanting the same |
| SE7810977L (en) * | 1978-10-20 | 1980-04-21 | Kubat Josef | FORM EXPRESSION PROCEDURE USING POLYMER MIXTURES INCLUDING HIGH MOLECULES HIGH DENSITY POLYETTE |
| US4205400A (en) * | 1978-12-04 | 1980-06-03 | Zimmer Usa, Inc. | Metallo-polymeric prosthesis with cavitied interconnection |
| FR2578780B1 (en) * | 1985-03-12 | 1987-08-14 | Commissariat Energie Atomique | HIGH MOLECULAR WEIGHT POLYOLEFIN PART, PARTICULARLY FOR JOINT PROSTHESIS, AND ITS MANUFACTURING METHOD BY CLOSED MATRIX FORGING |
| US4750905A (en) * | 1985-07-10 | 1988-06-14 | Harrington Arthritis Research Center | Beam construction and method |
| US5064439A (en) * | 1987-01-20 | 1991-11-12 | Richards Medical Company | Orthopedic device of biocompatible polymer with oriented fiber reinforcement |
-
1990
- 1990-03-02 FR FR9002636A patent/FR2644057A1/en active Granted
- 1990-03-03 DE DE4006714A patent/DE4006714B4/en not_active Expired - Lifetime
- 1990-03-06 AU AU50762/90A patent/AU632095B2/en not_active Expired
- 1990-03-07 IT IT19594A patent/IT1241681B/en active IP Right Grant
- 1990-03-07 CH CH72390A patent/CH686341A5/en not_active IP Right Cessation
- 1990-03-08 GB GB9005261A patent/GB2231800B/en not_active Expired - Lifetime
- 1990-03-08 JP JP02055157A patent/JP3103088B2/en not_active Expired - Lifetime
- 1990-03-08 ES ES9000689A patent/ES2021966A6/en not_active Expired - Lifetime
- 1990-03-08 CA CA002011724A patent/CA2011724C/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| GB9005261D0 (en) | 1990-05-02 |
| GB2231800B (en) | 1992-08-19 |
| GB2231800A (en) | 1990-11-28 |
| JPH02297360A (en) | 1990-12-07 |
| DE4006714A1 (en) | 1990-09-13 |
| ES2021966A6 (en) | 1991-11-16 |
| IT9019594A0 (en) | 1990-03-07 |
| CH686341A5 (en) | 1996-03-15 |
| DE4006714B4 (en) | 2006-01-26 |
| AU5076290A (en) | 1990-09-20 |
| AU632095B2 (en) | 1992-12-17 |
| IT1241681B (en) | 1994-01-31 |
| IT9019594A1 (en) | 1991-09-07 |
| CA2011724A1 (en) | 1990-09-09 |
| FR2644057A1 (en) | 1990-09-14 |
| FR2644057B1 (en) | 1995-04-21 |
| JP3103088B2 (en) | 2000-10-23 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| EEER | Examination request | ||
| MKEX | Expiry |