WO2007144000A2

WO2007144000A2 - Medical device comprising a metal fabric for insertion into a joint

Info

Publication number: WO2007144000A2
Application number: PCT/DK2007/000290
Authority: WO
Inventors: Sune Lund Sporring; Ole Olsen; Tom Løgstrup ANDERSEN; Povl BRØNSTED
Original assignee: Cartificial A/S
Priority date: 2006-06-14
Filing date: 2007-06-14
Publication date: 2007-12-21
Also published as: WO2007144000A3

Abstract

The present invention relates to implants used for alleviating and/or preventing conditions relating to damaged joints involving articulating surfaces. The implants comprise fibre of polymer and/or metal that is preferably in a fabric. The implant can be used as an artificial joint, as part of an artificial joint or as an artificial joint spacer made to replace the missing cartilage or to improve the slidability between two natural and/or artificial components of the body, or between a natural and artificial component. The product of the invention can be used to partly or entirely coat medical products or to make up implants partly or entirely.

Description

Title

Medical device comprising a metal fabric for insertion into a joint

Field of invention

The present invention relates to a method and a medical device for alleviating and/or preventing conditions relating to damaged joints involving articulating surfaces. Especially the present invention relates to medical products which are made of metal fibre arranged in a fabric or in a 3D network. The product of the present invention can be used as an artificial joint, as part of an artificial joint or as an artificial joint spacer made to replace the missing cartilage or to improve the slidability between two natural and/or artificial components of the body, or between a natural and artificial component of the body. All patent and non-patent references cited in the application, are also hereby incorporated by reference in their entirety.

Background of invention

At present, joint damage, such as cartilage damage, is treated by replacing the joint with an artificial joint. However, serious complications are caused by the replacement of artificial joints, in particular a high occurrence rate of loosening problems resulting in breakage of the bones around the artificial joint. In the case of cartilage damage a repair with cartilage substitution placed into intact bones is to be preferred instead of replacing the entire joint.

A conventional prosthetic joint implant may include single or multiple components. For example, a joint implant often referred to as a mobile bearing implant may include a bearing component that is interposed between first and second components. The bearing component extends the range of movements that can be accommodated, such as sliding and rotational movement.

Implantation of these prosthetic devices is usually associated with loss of underlying tissue and bone and, with some devices, serious long-term complications associated with the loss of significant amount of tissue and bone can include infection, osteolysis and also loosening of the implant. Such joint arthroplasties can be highly invasive and require surgical resection of the entire, or a majority of the articular surface of one or more bones involved in the repair. Typically with these procedures, the marrow space is fairly extensively reamed in order to fit the stem of the prosthesis within the bone. Reaming results in a loss of the patient's bone stock and over time subsequent osteolysis will frequently lead to loosening of the prosthesis. Further, the area where the implant and the bone mate degrades over time requiring the prosthesis to eventually be replaced. Since the patient's bone stock is limited, the number of possible replacement surgeries is also limited for joint arthroplasty. In short, over the course of 15 to 20 years, and in some cases even shorter time periods, the patient can run out of therapeutic options ultimately resulting in a painful, non-functional joint.

Another concern with prosthetic joint implants, such as a mobile bearing implant, is to ensure full range of appropriate motion. This must be balanced with the risk of dislocation of the device.

US 2004/0225371 describes a liner of titanium to be located between a prosthetic acetabular cup and a prosthetic femoral head. The liner has a lip member to hold the liner in a position between the acetabular cup and the femoral head.

US 2006/0052873 describes an implant for replacement or partial replacement of a joint, where the implant comprising a knitted fabric should have comparable physical properties to the surrounding tissue of the joint where it is to be inserted.

US 2006/0149389 describes a corrective element for the articulation between the femur and the pelvis. The implant is a shell-like implant with a recess for the ligament of the hip joint. The implant only fills out a part of the area between the femur and the pelvis and is described to self-center in the joint. The implant has an insertion edge in which the thickness decreases to zero, this edge is to be located be- tween the femoral head and the pelvis when in use. With such an implant there is a risk of luxation or destabilisation of the device leading to undesired implant location in the joint possibly leading to increased pain and reduced mobility. This is especially so since the arthritic joint will be expected, with respect to a healthy joint, to be deformed and the bone severely roughened with cyst formation. In particular, the invasive character of the fixation of the prostheses such as anchoring of the prosthesis with screws and pins may result in numerous side-effects such as risk of infection, loosening as mentioned above, damage on excising bone due to interruption of blood supply and necrosis.

A device for replacement within a joint should preferably enable the normal function and movements of the joint. Weight-bearing joints, in which movement in more than one direction takes place, are normally rather difficult to replace.

A prosthetic device should enable the normal movement of the joint. During walking, the normal movement of for example the hip joint corresponds to about 37°-41° flexion/extension, 2°-14° adduction/abduction and a rotation of about 2°-16°. During movement from standing to sitting position a flexion of hip joint corresponds to a movement from 0 to 90 degrees. When studying the movement of femoral caput to the acetabulum the latter movement includes a rotation of 90 degrees.

Many medical devices are implanted into load-bearing joints such as knees, hips, etc, or utilised in the human body where mechanical function provide high strength or shape stability such as heart valves, breast prosthesis, stent, catheter, etc. As such, these medical devices must be very strong and possess a high degree of wear resistance. Prosthetic medical devices manufacturers constantly work toward developing better products by improving their physical properties. Improved wear resistance, for example, is a desirable quality to impart to a prosthetic medical device. Improving wear resistance without losing strength or causing oxidative degra- dation is a difficult balance to obtain.

A need for improved prosthetic medical devices with improved wear resistance exists.

Summary of invention

The present invention relates to medical devices which may be used in damaged joints involving articulating surfaces.

The medical device according to the invention may comprise • at least one fabric of one or more metal fibre optionally further including one or more polymeric material and/or

• a 3D network of polymer fibre and/or metal fibre and/or

• at least one aperture which is at least 2 cm in diameter.

The at least one fabric may also be at least one 2D network. Fabrics, 2D networks and 3D networks of polymer and/or metal may be used together in one medical device or in different units of a medical device.

In a preferred embodiment the medical device comprises a cup-shaped device made from at least one fabric and/or 3D network of metal fibre. Optionally the device further comprises polymeric material as described elsewhere herein.

The device may also comprises one or more metal components which are selected from the group of powder, granulate, chopped fibres, long fibres, 2D structural components like plates, 3D structural components like shaped plates or hemicircles with holes. These types of material may or may not be combined with the fiber types of metal and/or polymer as describes elsewhere herein.

Biocompatible polymers and/or biocompatible metals can be used to make up the device. Polymers and metals are described elsewhere herein.

A device or part of a device made up according to the present invention may be used for any implant which can be positioned into an individual. Especially implants to be positioned into joints can be made of the material described herein, such as an acetabular cup, a spacer to be located between an acetabular cup and a head of a hip stem, or an implant to be used for interpositional arthroplasty. The head of the hip stem can be made of metal or a ceramic material. The device may also be a cup shaped spacer which is positioned between the natural femoral stem or a metal femoral stem and a natural acetabular cup or a prosthetic acetabular cup.

In a preferred embodiment the medical device is a spacer or cartilage implant as described above, where the implant is not locked or physically attached to an acetabular cup or to a femoral stem, although being in contact with the natural and/or prosthetic cup and stem. The implant may hereby move freely within the joint independently of the movement of the acetabular cup and femoral stem. The implant remains free and is not fixed by primary or secondary fixation. Its shape utilizes the formation of the joint to remain within the joint and the shape also secure self- centering of the device or at least the device will not slip out of the joint or be inap- propriately located within the joint. Hereby the implant achieves the possibility to restore the correct articulation of the joint without having to dislocate the head of the femur.

A hip joint in function is subjected to fluctuating forces due to the load of the moving individual. The forces vary between 1 to at least 15 times the body weight of the individual. Thus an implant to be positioned between to natural parts of a joint need to be able to withstand these huge forces which is subjected to the implant in the form of pressing and drawing. The actual influence on the implant is depending on the actual position of the joint together with the actual load. If the implant material is too soft it will be torn up at least partly resulting in pain when the individual uses the joint. The ends of natural bones in a joint are often deform and filled at least partly with small edges and rough spots. This also imposes specific demand of the implant material.

A medical device produced from the materials described herein as well as devices produced by other methods may be coated or covered partly or entirely with a metal material of the present invention, the metal material optionally comprises one or more polymeric component in the form of fibre and/or non-fibrous material.

The medical device according to the invention may have an upper surface, a lower surface and at least one edge and wherein at least the one edge may be sealed by a collar. The collar can be made of a material according to the present invention, e.g. it can be made with fabrics, 2D networks and/or 3D networks of polymer fibre and/or metal fibre where the fibre are connected to each other or with another poly- mer and/or metal material as described herein.

Also the collar may be made of a polymeric component and/or of one or more metal components. The surface or a part of the surface of a medical device can be made smooth by using the material according to the present invention. The device may comprise at least a first and a second side, wherein the at least first side is made of a first polymeric component optionally further comprising one or more metal components and wherein the part of or the entire of the first and/or second side has a frictional resistance of less than 0.5 Newton.

The smooth surface can be made by using a material according to the present invention, e.g. it can be made with fabrics, 2D networks and/or 3D networks of poly- mer fibre and/or metal fibre where the fibre are connected to each other or with another polymer and/or metal material as described herein.

The surface of the device according to the invention optionally being a smooth surface may further include one or more cavities.

Also the device may have at least one through-going perforation which is not for ligaments. The perforation may have a diameter of at least 0.01 mm and can conduct liquid from one first side of the device to another second side of the device. Larger perforation or apertures may also have a diameter of at least 1 cm and fit to the protrusion of a bone of an individual such that the protrusion partly or substantially fully fill the perforation of the device.

The medical device according to the present invention may be two parts or units which fit into each other, the device comprise at least a first unit with at least a con- vex surface and a second unit with at least a concave surface, where the convex and concave surface is congruent with each other and the first unit fit partially or entirely into the second unit, and the first and/or second unit comprises at least one of the polymeric and/or metal component/materials described elsewhere herein.

Each unit of the device can be made by using a material according to the present invention, e.g. it can be made with fabrics, 2D networks and/or 3D networks of polymer fibre and/or metal fibre where the fibre are connected to each other or with another polymer and/or metal material as described herein. The first and second unit can have substantially similar sizes, or be of different sizes. The units may be movable when compared to each other, and the units can continue to be in contact during a movement of the body and/or return to be in contact when a movement is finished by an individual.

The medical device according to the present invention may also be thicker at the periphery of the device. The device may comprise one or more metal components, wherein the device has a middle area which at least in one dimension is surrounded by an outer area, and wherein the thickness of the outer area at least partly is larger than the thickness of the middle area, and the outer area ends in at least one edge of said device.

The device may have any suitable shapes, e.g. cup-shaped or approximately cup- shaped, and wherein the middle area is the top i.e. the rounded part of the device and the outer area is a skirt. The skirt may be thicker that the middle of the top.

The device may also be a layered device. The device in a layered structure may comprise

• at least one upper layer of a first polymeric and/or metal component, • a middle layer of a second polymeric and/or metal component, and

• at least one lower layer of a third polymeric and/or metal component.

In the layered device, the chain length of the first polymeric and/or metal component and the third and/or metal polymeric component is longer than the chain length of the second polymeric and/or metal component. Only one of the components of the first or third polymeric and/or metal component need be longer that one of the components of the second polymeric and/or metal component.

In a layered device as described above, each layer may itself be composed of at least two sub-layers of polymeric/metal fabric and/or a 2D network and/or a 3D network.

The metal used in the device may be one or more metals selected from the group of metal and metal alloys of titanium, tantalum, gold, silver, chromium-cobaltum, zirconia, cobalt-chromium-molobdenum alloy and Stainless Steel alloys and/or a ceramic of one or more of these metals and alloys. Other metals may also be included e.g. in the alloys.

The polymers and metals including alloys used may be in the form of e.g. a powder, granulate, chopped fibres, long fibres, 2D structural components like plates, 3D structural components like shaped plates or hemicircles with holes. Also a combination of these forms may be used.

Instead of using fabrics, 2D networks and/or 3D networks of polymer fibre and/or metal fibre to produce the devices as described above, it may also be possible to use polymers and/or metals which are suitable for injection moulding, these materials may further include components of polymer and/or metal, as described herein.

Description of drawings

Fig. 1 illustrates a longitudinal section of a cup-shaped medical device. The device may also be oval cup-shaped where the device is longer in one direction than in another direction. The material of the device illustrated in all the figures may be any metal and/or polymeric material as described elsewhere herein.

Fig. 2 illustrates a cross-section of a cup-shaped medical device.

Fig. 3 illustrates a longitudinal section of a cup-shaped medical device taken along section A-A in Fig. 2. The device has a rounded top section at the left and at the right a skirt in which the material may be thicker than the material at the top of the device.

Fig. 4 illustrates a cup-shaped medical device. The line denoted "E" illustrates equator, which is the border between the rounded top "T" and the skirt "S".

Fig. 5 illustrates a cup-shaped medical device (2) with a collar (1 ) located at the edge of the device. The device may further have an aperture (A). The aperture may be located as indicated in the figure or be located in another place e.g. in the centre of the rounded top. The size and shape of the aperture can be different that indicated in the figure. The medical device may also have an aperture but no collar. The medical device may be of any material described herein the material may be of metal and/or polymer and may or may not include fibre e.g. as in a fabric or as a reinforcement.

Fig. 6 illustrates a longitudinal section of a cup-shaped medical device. The device has a skirt in which the material is thicker than the material at the top of the device. Furthermore the device has a collar here illustrated with a marker.

Fig. 7 illustrates the edge of the medical device in Fig. 6. The edge is enclosed by a collar, and this collar supports a marker (3).

Fig. 8 illustrates an embodiment of the invention, a cup-shaped device located in the hip joint between a natural femoral head and a natural acetabulum of the pelvis. The femoral head and/or acetabulum may be natural or a prosthesis. Although the device is illustrated to have a similar thickness all over the device, it may be thicker in e.g. the skirt. The device may be self-adapted as described elsewhere i.e. deformed by the bone of the joint. The skirt may be shorter or longer than illustrated in relation to the size of the femoral head.

Fig. 9 illustrates different orientation of the fibre within woven fabrics. 2, 3 and 4 orientations of the fibre are shown. The fibre may be in one or more layers as described elsewhere herein. The thickness of the fibre may be equal when measuring the average thickness, also the thickness may be different with respect of the fibre in different orientation and/or with respect of fibre in one orientation.

Detailed description of the invention

In an aspect of the invention a medical device comprises • at least one fabric of one or more metal fibre and/or

• at least one wire of one or more metal fibre and/or

• at least one 3D network of one or more metal fibre.

In another aspect the device comprises one or more metal components which are selected from the group of powder, granulate, chopped fibres, long fibres, 2D struc- tural components like plates, 3D structural components like shaped plates or hemi- circles with holes. These types of material may or may not be combined with the fiber types of metal and/or polymer as describes elsewhere herein.

Optionally the medical device may also be further combined with any polymeric materials as described elsewhere herein.

The present invention provides a desirable balance of improved wear resistance and high tensile strength and toughness in the material used for medical devices. The implant according to the invention may be of metal and optionally further include another material such as a polymeric material e.g. as a composite with one or more polymeric materials. The products of the invention has a high tensile strength and improved wear resistance as well as the capability to absorb shocks, impacts and pressure load, also it reduces the amount of tearing off.

The medical device may be designed to occupy the pelvis cup; to occupy at least part of the intra-articular cavity to partly or completely fill the role of natural cartilage within a joint; and/or to be an interpositional arthroplasty. The devices or their units may be designed to occupy the whole of the cavity or merely a portion of the intra- articular cavity, such as the portion of the cavity where cartilage is worn or where much of the pressure is exerted.

In a preferred embodiment the medical device is to function as artificial cartilage within a joint with a natural femoral head and a natural acetabulum cup.

In a preferred embodiment of a method for insertion of the medical device into an individual, before positioning the medical device between a femoral head and an acetabulum cup the femoral head may not be reamed or may be minimal reamed e.g. by only removing osteophytes and/or cysts if present.

The medical device could also be described as an acetabular component prosthesis adapted for positioning in a natural pelvis, the prosthesis comprising: a cup shell as described herein having a generally convex outer surface adapted to be in contact with the socket or acetabulum of the pelvis when in use, and a generally concave inner surface adapted to be in contact with the femoral head. Preferably the acetabulum and the femur are the natural bone of the individual. The medical devices may also be designed to replace at least part of a bone within a joint together with the intra-articular cavity to partly or completely fill the role of the bone which is replaced and to partly or completely fill the role of natural cartilage within a joint.

In a preferred embodiment the medical device as described herein is not locked or physically attached to an acetabular cup or to a femoral stem, although being in contact with the natural and/or prosthetic cup and stem. The device may hereby move freely within the joint independently of the movement of the acetabular cup and femoral stem. By "locked" can also be understood specific formations of the acetabular cup and the device with congruent angles as described in e.g. US 2006/0167556.

The material for the medical devices is primary at least one metal or metal alloy although other materials such as polymers as described elsewhere herein can be used. The polymeric materials may be used together with the metal.

In an embodiment of the invention a medical device comprises at least one fabric of one or more metal fibre and/or of one or more polymer fibre and/or a 3D network of polymer fibre and/or metal fibre. The polymer fibre and metal fibre which may be used are described elsewhere herein.

In an embodiment the device comprises an area at least defined by the outermost fibres of the network, this area is filled up with one or more polymer optionally further comprising one or more metal components or said area is filled with a metal or metal alloy. The polymer and metal components used may be anyone described elsewhere herein. The fibres of the network may during the production process of the device be located substantially in the position where the fibres will be located in the final device.

Also the fibres making up the network (fabric, 2D or 3D) may during the production process be located in different positions when compared to the location of these fibres in the final device. Hereby a volume which can be filled up by another type of material or by a similar material in another configuration such as shorter fibre, may be defined by the outermost fibres of the network and is a volume defined by the corresponding volume of the network in the final device, hereby the volume defined by the network of fibres is larger in the production process than the volume defined by the final device.

In the production process heat and/or pressure may be used to connect polymers and/or metals in different forms to each other.

Also the metal fibre and the metal components can be different types of metal or similar metals although in different configurations e.g. in different fibre length and/or different fibre thickness.

In an embodiment the device comprises a number of layers of e.g. fabrics of one or more metallic components e.g. 2, 3, 4 or more layers, optionally one or more of these layers further comprises one or more polymeric components. The device may include more than one layer of a metallic component, these layers may optionally comprising one or more polymeric components. Preferred number of layers is described elsewhere herein.

In another embodiment the device comprises a number of layers of a polymeric component e.g. 2, 3, 4 or more layers, optionally one or more of these layers further comprises one or more metal components. The device may includes more than one layer of one polymeric components, these layers may optionally comprising one or more metal components. Preferred number of layers is described elsewhere herein.

In an embodiment the device comprises a part of or the entire of a traditional total hip joint prosthesis with a natural or metal and/or ceramic femoral stem articulating against an acetabular cup to be placed in the pelvis. The acetabular cup may be a PE acetabular cup, a UHMWPE acetabular cup or a metal acetabular cup, and the metal or ceramic femoral stem and/or the acetabular cup may be covered with a material according to the possibilities described elsewhere herein.

In an embodiment an acetabular cup as described above may be used together with a cup-shaped spacer made of a material in accordance with the description else- where herein. In an embodiment of the invention the device is part of a hip joint prosthesis or another prosthesis, and the device comprises a spacer between two parts of a prosthesis or between a part of a prosthesis and a natural bone of an individual. In a preferred embodiment a cup-shaped spacer is positioned between the natural femoral stem or a metal femoral stem of a hip joint prosthesis and a natural acetabular cup or a prosthetic acetabular cup.

In another embodiment the device is a spacer to be positioned between two natural bone parts of an individual e.g. as for interpositional arthroplasty.

In another embodiment the device is homogenous in dimensions around an axis (e.g. section A-A in Fig. 2), and the axis is a central axis according to one dimension of the middle area. The axis indicates a line separating the device into two substan- tially equally sized units.

In an embodiment, the device is heterogeneous in dimensions around an axis, and the axis is an approximately central axis according to one dimension of the middle area. The axis indicates a line separating the middle area of the device into two sub- stantially equally sized units. The outer area is larger on one side of the device than on other sides of the device.

In an embodiment the middle area of the device (e.g. section T in Fig. 4) and the at least one edge are in different planes (e.g. section S in Fig. 4).

The device may thus be homogeneous or non-homogeneous in shape and/or homogeneous or non-homogenous with respect to the planes of the edges.

In an embodiment at least one edge of the device is in a different plane than the middle area of the device. Also one edge can be in one plane and at least another edge in another plane, and when these planes are projected to a similar plane, this similar plane constitutes an outline of the edge or edges of the device, where this outline has a shape that is selected from a shape from triangular to circular including oblong designs. The shape of the device may be any possible figure in each dimension where the shape may constitute a surface being flat, curved, waved, undulated, bent, bowed, crooked, while the overall shape of the device may be but is not limited to circular, oval, triangle, squared, rectangle, cubed, bowl, cup, crown, cap, basin, heart, egg, kidney, figure of eight. A preferred shape is cup or hemispherical. The thickness of the device may also vary, as described elsewhere herein.

In an embodiment the device is cup-shaped or approximately cup-shaped, and the middle area is a top and the outer area is a skirt.

In the embodiment where the device is a cup-shaped device with a rounded top, a line separating the top and the skirt can be denoted "equator", where the outmost part of the skirt is the edge of the device (Fig. 4). Equator may be located around the cup-shaped device where the curvature of the cup changes to follow the tangent to the cup.

The cup-shaped or approximately cup-shaped device may have a substantially uniform thickness all over the device or the device may have various thicknesses. Preferred is a top of a first thickness and a skirt with a second thickness. The second thickness can be at least 25% larger that the first thickness, such as at least 50%, such as at least 75%, such as at least 100%, such as at least 125%, such as at least 150%, such as at least 175%, such as at least 200%, such as at least 225%, such as at least 250%, such as at least 300%, such as at least 350%, such as at least 400%, such as at least 500% where the second thickness may increase gradually from the first thickness to the thickness mentioned above.

Preferred is a cup-shaped device with a second thickness that is about 200% of the first thickness.

In another embodiment the thickness of the outer area is at least 5% larger than the thickness of the middle area. The thickness of the middle area is measured at the location where the middle area is thinnest and the thickness of the outer area is measured at the location where the outer area is thickest. The thicker outer area compared to the middle area provide the device with an increased stability in the outer area, especially when compared to a device with a uniform or substantially thickness as of the middle area. The stability of the device implies that the device to a lesser degree bent or flex in the outer area when located in the joint of an individual. Especially a cup-shaped or substantially cup-shaped device has the advantages as mentioned.

A thin device increases the flexibility of the device, hereby the mammal such as a human is subjected to lesser degree of inconveniences when the device is located in a joint of this mammal. A thick outer area thus increases the stability of the device without decreasing the stability of the device.

In an embodiment the device further comprises one or more reinforcing fibre elements which may be formed of one or more materials selected from the group con- sisting of: graphite fibre, polyaramid, polyamid, polyesters, polyamides, nylon fibre, carbon fibre, glass fibre, collagen fibre, ceramic fibre, polyethylene fibre, poly(ethylene terephthalate), polyglycolides, polylactides, stainless steel fibre, cobalt-chrome alloy, titanium, titanium alloy, or nickel-titanium shape memory alloys, biocompatible polymeric materials, biocompatible metallic materials e.g. fibre as described herein and other natural and synthetic materials compatible with the matrix of the device.

In an embodiment a medical device made of one or more metal components which are selected from the group of powder, granulate, chopped fibres, long fibres, 2D structural components like plates, 3D structural components like shaped plates or hemicircles with holes includes one or more of the reinforcing fibre elerments.

The reinforcing material may be in the form of a network of fibre formed of one or more materials as mentioned above, where the network is embedded in one or more polymers and/or in one or more metals. The network or the fibres are embedded in a polymeric/metallic material, where the polymers/metals are described elsewhere herein.

The fibre of the device either being the fibre making up the main part of the device and/or being reinforcing fibre may further be treated, for example, chemically or me- chanically etched and/or silanized, to enhance the bond between the fibre itself and/or between the fibre and the matrix e.g. a polymeric matrix. The fibre preferably takes the form of long, continuous filaments, although the filaments may be as short as 0.1 to 4 millimeters. Shorter fibre of uniform or random length might also be em- ployed. The fibrous element may take the form of a fabric. Fabric may be of the woven or non-woven type and may be preembedded with a polymeric material as set forth herein. The fibrous component may be present in the fiber reinforced composite material in the range from about 20% to about 85%, and more preferably between about 30% to about 65% by weight, e.g. about 40%, 50%, 60%.

The device and units hereof may be designed not to interfere and to be non-invasive with regards to intra-articular components when the device is in the joint cavity by means such as a slit in the body of the device.

Moreover, non-interference of the intra-articular components may be achieved by a hole which runs through the body of the device; that is to say the device may comprise a hole through which intra-articular components may pass. When loading the device, the slits may serve to pass intra-articular components through the body of the device. The slits in this embodiment run from the periphery of the body of the device to the hole through which the intra-articular components pass after the device is implanted or loaded.

Typically, and to at least some extent, the device is adapted in its structure and/or material composition to alleviate conditions associated with worn cartilage by provid- ing a spacer function and/or to exert pressure distribution in the joint when the joint is loaded and/or to provide at least part of the sliding/rotating movement of the joint by internal movement of at least part of the device.

It is also an object of the present invention to provide a method for non-invasive locking of a device within a joint. In addition, the method may be independent of use of cement or bony ingrowth of the device. When the device comprises units e.g. units for a total hip prothesis or parts thereof, at least one unit may be secured to the bone when inserted into the individual and/or provided with means for bony ingrowth. A still further object of the present invention is to provide a kit being a part of a hip prosthesis; a kit being all the parts of a hip prosthesis; or a kit for use in a method for non-invasive locking of a device within a joint.

It is also an object of the present invention to provide a method for preventing damage between mating surfaces or articulating surfaces within a joint such as between the femoral head and the acetabulum of a hip joint.

A more specific object of the present invention relates to a prosthetic device for in- sertion into a joint cavity of a joint of a vertebrate such as a human, the device is being adapted to provide a spacer function and/or to exert stress distribution in the joint when the joint is loaded and/or to provide at least part of the sliding/rotating movement of the joint by internal movement in the material of at least part of the device, the device being capable of being fixed or retained in the joint cavity in a manner which is substantially non-invasive with respect to cartilage and bone natively present in the joint cavity.

When inserted into the joint cavity the device can be constructed to locking itself to an intra-articular component and thereby being fixed or retained in the joint cavity.

The physical-structural features of the device relate to the size, form or shape of the device as well as the structural components and design components of the device.

Size and Shape

The overall shape of the device is such that it substantially fits into the excising anatomical dimensions of the joint of an individual. In general, the size and shape of the device may be such that the device fits into the intra-articular cavity in that it may partially or fully occupy the space defined by the cavity, this depends on the type of device. For some of the joints it is preferred that the extent of the device, when positioned in the joint cavity, is larger than the normal extent of cartilage on the bone end in that joint. The size and shape of the device may also be determined according to the size and shape of the femoral head. Hereby the device may be shaped with the ridges of the natural femoral head.

In an embodiment, a hole runs through the body of the device to allow intra-articular components to traverse the body of the device and thus be surrounded by the device.

In an embodiment, the device may be construed in a liberal sense as essentially torus-shaped in that the device can be of a plurality of geometrical shapes, symmetrical and asymmetrical, optionally comprising a hole which runs through the body to create an internal tubular passage through which intra-articular components may pass.

The device may also be ball-shaped, disc-shaped, spherical, globular-shaped, cup- shaped, cone-shaped, ring-shaped, cylindrical and have convex, concave, or flat surfaces. Accordingly, the body of the device can e.g. be in the form of a horseshoe, a curl, ring-shaped, circular or semicircular so as to be suitable for fitting into the anatomical dimensions of the particular joint. Furthermore, the device may be asymmetrical.

The body of the device may be of a geometrical shape comprising a surface having the form of body shaped by rotating a circle about a coplanar axis which does not intersect the circle. It may be ball-shaped, disc-shaped, globular-shaped, cup- shaped, cone-shaped, ring-shaped, cylindrical and may comprise convex, concave, or flat surfaces. In some aspects it is characterised in that it comprises a hole extending from one surface of the body of the device to the same or another surface, creating an internal tubular cylinder. This internal tubular cylinder may be straight if the hole extended to two parallel surfaces, curved if the hole extends to perpendicu- lar surface, U-shaped if the hole extends to two parts of the same surface or a combination of one or more of these internal shapes and thus tortuous.

Certainly, given that the overall shape of the device is such that it substantially fits into the excising anatomical dimensions of the joint, it is anticipated that the body of the device may be asymmetrical or of no definable shape so as e.g. to the fill the intra-articular cavity, to allow for the movement of the intra-articular components during the flexing of the joint, to support intra-articular components or to support matter which form the walls of the cavity.

It is preferable that the shape of the device is such that it does not impede the normal functioning of the joint and its components. The device may have a different shape than the component of the individual which the device is to replace, e.g. the cartilage of a hip joint may be replaced by a cup-shaped device located on the femoral head.

It is particularly anticipated that the body of the device may be asymmetrical or of no definable or uniform shape when the device is for use in a hip joint. Alternatively, the shape of the device may be such that it resembles the native cartilage, or part thereof, naturally present in the joint cavity.

Accordingly, in the case of a hip joint, the shape of the device may be such that it fits into the existing space of the joint cavity comprising ligamentum capitis femoris, the "walls" of the space being defined by the concave shape of the acetabulum and by the convex shape of the femoral head.

Moreover, the overall shape of the device may be a result of an assembly of more than one units of the device, such as the assembly of two or more rings of different sizes stacked upon each other so as to form a cone-shaped device. The assembly of units may be done in vivo or ex-vivo.

Furthermore, in an embodiment, the overall shape may be such that the device is capable of locking itself to an intra-articular component if present in the joint and thereby being fixed or retained in the joint cavity. When the intra-articular component is a ligament, the shape may be such that the ligament is surrounded or substan- tially surrounded by the device.

However, the overall shape of the device may have any other form as long as the material is of such a character that the device when present in situ fits into the joint cavity, for example due to elastical deformation of the device. The elastical deformation of the device may be such that the presence of ligamen- tum capitis femoris results in a shape leaving room for the ligamentum. Otherwise, the surface of the upper part of the device facing the acetabular cavity may comprise a groove embedding the ligament.

The shape of the device may be formed from a moulding of its materials or from a casting process. It may alternatively be the result of a framed structural construction or skeletal assembly. It may be solid in that the body of the device is not hollow but rather such that the material of the device comprises all or essentially all of the space between two surfaces. The moulding, casting, construction or assembly may form a device into a uniform or non-uniform shape.

The device may be uniform in its stiffness or compressibility. However, when loaded, the material may have a tendency to deform in such a way that the locking mecha- nism is altered. This may occur if the element adapted to surround the ligament, when present in situ, has a slit which expands or gapes upon loading when the device is pressed together. This gaping may be further pronounced when the patient is e.g. walking whereby the ceiling of the acetabulum is pressed down on the upper surface of the device and the lower surface of the device is pressed down on the spherical surface of the femoral head.

Due to the rolling movement (rotation within the joint) of the femoral head, the possibility exists that the femoral head may press itself up into the slit of the device during the movement. In such cases, the press distribution and/or internal movement of the device may be limited to a minor part of the device that may result in an undesirable increased pressure on that portion of the device. Finally, contact between the femoral head and the acetabulum may occur in case the femoral head penetrates through the device. However, a device comprising parts overlapping each other can prevent this possible undesirable effect.

Accordingly, as mentioned above, the device may be curl-shaped whereby the device with respect to the slit or opening has overlapping parts which do not represent a complete opening in the loading direction.

In a preferred embodiment the device does not include a slit for a ligamentum. The size of the prosthetic device according to the invention may be of any size corresponding to the dimensions of the joint. In a hip joint, a suitable size is normally one that allows the diameter of the device to be about the same, or less than the diameter of the femoral head. However, on some occasions the diameter may exceed that of the femoral head. The size may also depend on the degree of damage of the native cartilage of the joint. Moreover, the space available within the joint in the individual may have an effect on the preferred diameter. Also the compressibility of the material should be taken into account. In the case in which the material is highly compressible, the device may increase in diameter upon loading of the joint; when loaded, the device should generally cover the surface area which is covered with cartilage in the normal joint, e.g., in the hip joint, the surface of caput femoris should preferably be substantially covered when the joint is loaded to avoid contact of the surface of the femoral head with the acetabulum.

When the device is a cup-shaped device to be used in a joint as a spacer, the cup- shaped device may have an inner diameter that is slightly larger than the diameter of the bone or implant which the cup is to be located on. A cup for a hip joint may have a diameter that is slightly larger than the diameter of the femoral head, this femoral head being the natural femoral head of an individual or an artificial femoral head. "Slightly larger" means that the cup can have an inner diameter that is about 0.1 mm larger that the diameter of the bone to be put on, such as about 0.2 mm larger, e.g. about 0.3 mm larger, such as about 0.4 mm larger, e.g. about 0.5 mm larger, such as about 0.6 mm larger, e.g. about 0.7 mm larger, such as about 0.8 mm larger, e.g. about 0.9 mm larger, such as about 1 mm larger, e.g. about 1.1 mm larger, such as about 1.2 mm larger, e.g. about 1.3 mm larger, such as about 1.4 mm larger, e.g. about 1.5 mm larger, such as about 1.6 mm larger, e.g. about 1.7 mm larger, such as about 1.8 mm larger, e.g. about 2 mm larger, such as about 2.5 mm larger, e.g. about 3 mm larger, such as about 3.5 mm larger, e.g. about 4 mm larger, such as about 4.5 mm larger, e.g. about 5 mm larger.

The length of the diameter of the device is designed to fit into the particular joint, such as between 1-80 mm, preferable between 10-70 mm, more preferable between 30-65 mm, most preferred about 50 mm, when the joint is loaded. The diameter of the actual device depends on the size of the femoral head of the individual to operate.

The prosthetic device according to the invention may vary in thickness depending on the load of the joint, and the thickness of the device may also vary within the device.

The thickness of the device in the middle area and outer area is at least 0.1 mm, preferably between 0.2-60 mm, such as between 0.3-40 mm, preferably 0.4-30 mm, more preferably about 0.5-10 mm, most preferably about 0,6-3 mm in the unloaded stage. Depending on the material, the device may be highly compressible, whereby the initial thickness may exceed the above-mentioned upper limit. If only a limited rotation takes place in the joint, the thickness of the device may be decreased.

In one embodiment of the invention, the device is capable of locking itself to the in- tra-articular component by at least one element of the device surrounding the component in such a manner that displacement of the element, and thereby the device, is limited by interlocking with the component. The intra-articular component which is surrounded is preferably a ligament, such as a ligament natively existing in the joint cavity.

In one embodiment of the device according to the invention, the element completely or substantially completely surrounds the ligament.

Thus, one embodiment relates to a prosthetic device according to the invention re- lates to a device wherein the element interlocking with a ligament, when present in situ, permits the ligament to extend through the element and substantially exert its natural function on the joint.

In one aspect of the invention, the prosthetic device is intended for the articulation of a hip of a human, the device being adapted such that when present in situ in the human hip joint cavity, it comprises at least one element surrounding ligamentum capitis femoris. Accordingly, ligamentum capitis femoris represents the surrounded intra-articular element mentioned above. It is contemplated that the surrounding of the intra-articular component by the element may be a completely or substantially completely encircling of the ligament.

It is also preferred that the prosthetic device, when present in situ, comprises at least one ring-shaped or substantially ring-shaped element.

According to another embodiment of the invention, the element of the prosthetic device which is adapted to surround the ligament when present in situ has such a shape and such properties that it can be placed around the ligament and stay inter- locked with the ligament.

In a preferred embodiment the device according to the present invention comprises a shape without a slit etc. for one or more ligaments. Hereby ligaments may be removed from the joint of the individual before the device is arranged into the joint.

Structural Components

The device may comprise structural components which permit arrangement of the body of the device around native intra-articular components, or the structure of the device allows no arrangement of the body of the device around native intra-articular components.

When the prosthetic device according to the invention is a hip endoprothesis, the device may have a shape and structural components permitting arrangement of the body of the device around ligamentum capitis femoris.

When the prosthetic device according to the invention is a cup-shaped spacer and/or a cup-shaped acetabular cup to be used in a hip joint, the device may have a shape and structural components allowing removal of ligaments of the hip joint.

In an embodiment a prosthetic device according to the invention comprises a device wherein the element of the device interlocking with the device with an intra-articular component has such a shape and/or properties that it is capable of replacing or supplementing worn or damaged cartilage in the joint and/or is capable of prevent- ing wear of the native cartilage of the joint or of the bone tissue of the joint. The structure of the material of the device or of a part of the device may be in the form of fibres and filaments of polymers and/or metal which can be incorporated into the matrix in a braided, woven, spongy or spiral pattern, the fibres and filaments may have reinforcing properties. The polymer fibres may be inorganic fibres such as carbide, nitride, boride, carbon and oxide fibres, or the polymeric reinforcement may be of organic origin such as Dacron™. In a preferred embodiment the fibres are selected from polyethylene fibres, polypropylene fibres or a combination thereof.

The metal may be any suitable metal e.g. titanium, tantalym, gold, silver, steel e.g. stainless steel and/or chromium-cobaltum, and may be of any structure as described elsewhere herein.

The structure of the material of the device may comprise a layered or laminated structure, a core of one material or one or more interposed layers with different properties enabling an overall function of the devise suitable for providing a spacer function and/or to exert pressure distribution in the joint when the joint is loaded and/or to provide at least part of the sliding/rotating movement of the joint by internal movement of the device, or relevant part of the device. However, it is preferred that the material itself does not comprise interposed layers resulting in sliding between the layers and thereby tear on the mating surfaces within the device. Accordingly, the body of the device when ready to implant into an individual should be one continuous solid or semi-solid material.

In one embodiment of the invention, the device comprises a tubular passage through which the ligament can pass and be surrounded by the body of the device. Circular movement around the substantially central ligament is possible but replacement of the device is prevented. A further feature of the structure of the device may be that of a slit extending from the outer surface of the device and through the body of the device into the central tubular passage. The slit may be curl-shaped in the radial direction with the axis of the tubular passage being the centre.

The slit may curl or curve into the body of the device so as to form an S-, or C- shaped slit, or zigzag or spiral slit. The curl of the slit may be in the two dimensions of a disc shaped device, or may curl in all three dimensions in the case of a globular, spherical, cone-shaped or cup-shaped device.

Furthermore, in embodiments where the device comprises more than one unit, the curvature of the slit may be such as to form a zigzag, spiral or S- or C-shaped multi- unit slit.

In multi-unit devices, the outer surfaces of the parts of the unit which are in contact with each other may have a surface pattern preventing the units from sliding apart such as grooves or etching or jagged surface pattern.

Moreover, the overall shape of the device may be from an assembly of two or more elements of one device, such as two semi-circular elements assembled to form a ring or from the assembly of two elements obtainable from the cross-sectioning of a ring or globular device along their longest axis. As was the case for the surface of two units, two elements may have a surface pattern preventing the elements from sliding apart such as grooves or etching or jagged surface pattern. Thus, a device and its shape may be the result of an assembly of two or more elements and/or two or more units, each comprising surfaces designed to preventing slippage of units and/or elements.

If suitable, the device may comprise a material which functions as a frame for the shape or secures the device from opening when placed in situ, for example in the form of a shaped component having the properties of a spring or the like.

In one embodiment, the ring-shaped body of the device has a slit or other suitable means which enables the device to be placed in the position encircling ligamentum capitis femoris.

Upon loading the device into the joint, the element of the device surrounding the component, e.g. a ligament, and thereby interlocking with the component, may tend to open up due to deformation of the device in the form of flattening resulting in an increased diameter. When the diameter of the device increases, e.g. the diameter of a ring-shaped device comprising a slit, the adjoining surfaces of the slit may gape. As stated, during the compression, extension or rotation of the device when the device is present in a joint, the slit may have a tendency to gape and thus result in reduced weight-bearing effectiveness and/or result in trapping of intra-articular components within the seam of the slit. Preferably, the seam cannot be pulled apart in the direction of the plane of the seam by the mechanical pressure exerted by the body of the device conferred by the elastic properties of the material.

To prevent undesired slippage of the seam perpendicular to the plane of the seam, a variety of means may be incorporated into the design of the device so as to lock or adhere the two sides of the seam. Preferably, the locking or adherence means are reversible so as to allow removal or manipulation of the device after initial loading and use.

The seam is preferably characterised in that a smooth surface is formed in the plane of the seam.

To prevent the device from opening, the device preferably comprises overlapping or intersecting parts, such as lips or dovetails as is known by the person skilled in the art of mechanics or moulding. The two sides of the seam may be adjoined by means of an interlocking device such as a protrusion-hole device on sides of the seam. Alternatively, to prevent slippage in perpendicular to the plane of the seam, each side of the seam may be such that each side of the seam comprises an alternating sequence of angled grooves and corresponding extrusions. Moreover, the top and bottom portion of each side of the seam may comprise alternating teeth and sockets to prevent slippage. To prevent gaping such overlapping parts and their mating surfaces of the sides of the seam may have an interlocking surface structure. The pattern of such a structure may include depressions on the mating surface of one part and corresponding elevations on the other mating part of the device.

Accordingly, in one embodiment, the overlapping parts are such that the interlocking surface structures constitute grooves. These grooves may extend radially, primarily resulting in a decreased tendency of the device to "open up" at the area corresponding to the slit or the gap. The grooves may also be orientated in a circulatory structure preventing the mating surfaces from gliding or sliding apart from each other. Additionally, the structure may comprise a combination of both elements reducing undesired movement in both of the two directions, when the device is deformed during loading of the joint.

The terms "radially" and "circular" should be understood as relative to the centre of the device or relative to the part of the device where the ligament extends through the device. "Radially" meaning e.g. grooves being located along radii from the centre, and the term "circular" meaning that e.g. the grooves are located along the periphery of a circle around the centre.

In another embodiment, the pattern includes other prominences or knobs, including pointed elevations. Thus, any structure comprising an elevation on one mating surface and a corresponding depression on the other mating surface may result in a decreased movement between the mating surfaces. Accordingly, any structure of the mating surfaces which thereby functions as an interlocking "hook" is within the scope of the invention. The mating surfaces of the curls may have an interacting profile in the form of a shape or pattern such as grooved surfaces which prevent the surfaces from sliding apart by reducing sliding movements between the mating surfaces upon loading of the device.

Another preferred embodiment of the invention relates to the seam created by the slit in the body of the device, accounts for preventing of slippage or gaping of the seam by means of a chemically treated surface of the sides of the slit. One embodiment of this aspect of the invention anticipates adherence of the two sides of the seam by means of photolytically or thermally activating a reaction between the chemically treated surfaces of the sides of the seam once the device has been loaded into the joint. Preferably, this adherence is reversible.

In another embodiment, the device may also comprise two or more separate rings each having a slit which are arranged so that the slits are orientated in such a way that no direct opening exists in the loading direction, accordingly, the slits are displaced in the direction parallel with the axis of the device. Mating surfaces of such rings may also have an interlocking structure as explained above.

In a still further embodiment, the device is in the form of a curl, wherein the ring- shaped elements together have the overall shape of a cup. Also in this embodiment, the mating surfaces may comprise grooves preventing sliding movements of the mating surfaces upon loading.

In a still further embodiment, the device may comprise minor vertical slits on the outer periphery of the device, these minor slits, e.g., having a depth of 1-5 mm may

"absorb" the increasing diameter of the device upon loading. Preferably, the part of the device comprising the slits (the outer periphery) is not subject to heavy loading which could result in particulation of the edges of the device corresponding to the slits. These minor vertical slits on the outer periphery of the device may alternatively serve so as to not interfere with movable or immobile components of the joint within the cavity.

The device according to the invention may e.g. be processed by moulding of the material including extrusion and injection moulding. The device may also be proc- essed by pressure into shape e.g. combined with heating the material. However, any other means for preparing the device of the desired shape could be utilised.

In addition, the device may comprise a dye, a marker or other material enabling visualisation of the device such as by X-ray.

Material Features

The material features of the device related to features conferred by the chemical composition of the device.

It is well known in the orthopaedic field to use different types of materials for prostheses that are suitable for implantation in the body. The device may be produced from any material or combination of materials suited for implants.

The combination of materials can be varied according to the properties preferred for each device. However, for some implant types, the body of the device is constituted of metal components.

Preferably, the material of which the device is made is biocompatible, e.g. hemo- compatible, thromboresistant, non-toxic, and/or non-carcinogenic. In addition, the material should be resistant to pandiculation, and the solid surface of the material should be so that the surface tension is suitable for the interaction between the material and the biological surfaces.

Biocompatibility may be assayed through in vitro tests as well as animal tests. Enzymatic biodegradation may be used as indicative of biocompatibility. Furthermore, chondrocytes and fibreblasts may be grown on the material to evaluate the compatibility.

Finally, biocompatibility may be evaluated by implanting devices of the material in animals and examining the animal and/or device after a period of time.

Furthermore, the surface material could be a material or a combination of materials having self-repairing properties so that fissures, cracks or other ruptures on the sur- face do not exceed uncontrollable levels. However, the surface material is preferably continuous with the material of the rest of the device, e.g. the material may gradually merge into the material of the inner core or matrix of the device.

The surface of the material may be chemically treated so as to soften, rigidify or lubricate the surface of the device or parts thereof. The surface of the material may be coated so that the coating confers these properties, or may be treated so as to chemically alter the surface of the device so as to confer any of these properties. Alternatively, certain polymer surfaces may be modified by means of thermal or photolytic energy.

Also the surface treatment may be provided by incorporating surface treatment polymer, such as polyethylene and/or polyvinyl pyrrolidone, into the matrix to maintain the good surface properties.

Independent of whether the body of the device comprises one or two components, the body of the device may be treated resulting in a functional surface of the device being wettable by the joint fluid normally present in the joint cavity, in order to decrease any friction between the device and joint parts, such as bone, cartilage, ligaments and mucosa. Without being bound by theory it is also believed that a wetted surface reduces the risk of having the immune system recognising the device when implanted, which would otherwise lead to adverse effects of the device.

By the term "functional surface" is meant the external surface of the device, ie. the surface contacting joint cavity parts. Since the body of the device is often produced as one, two or even three dimensional networks, internal surface may be present in the body, the internal surfaces often corresponding with the external surfaces.

Preferred devices are composed of any metal, preferred is Stainless steel alloys, Titanium alloys or Cobalt/chromium alloys or any combination thereof.

Insertion

It is also an object of the present invention to provide a method for introducing a device according to the present invention into a joint of an individual. The method comprises:

a) locking the device to an intra-articular component and thereby fixing or retaining the device in the joint cavity in a manner which is substantially non-invasive with respect to cartilage and bone natively present in the joint cavity.

The method may further comprise any of the following steps before locking the device to the intra-articular component in the joint:

i) exposing the joint capsule by conventional surgery procedures,

ii) penetrating the joint capsule into the joint space leaving a passage for

iii) introducing the prosthesis into the joint capsule via the passage, the prosthesis having a shape suitable for being introduced through this passage.

Locking the device to the intra-articular component and thereby fixing or retaining the device in the joint cavity in a manner which is substantially non-invasive with respect to cartilage and bone natively present in the joint cavity may include encir- cling a ligament present in the joint with a ring-shaped element of the device such as a ring-shaped device having a slit extending from the periphery of the device to the central opening of the "ring".

The method may further comprise the steps of deforming the prosthetic device into a reduced volume or a slender shape before locking the device to the intra-articular component.

In the case of insertion into a hip joint, the insertion of the device is preferably per- formed after penetration through the head of the rectus femoris muscle leaving a passage having a substantial width for introducing means into the joint capsule without alteration of the function of the capsule after the surgery.

Means or instruments for inserting the device into the joint space can be in the form of forceps comprising means for deforming the device into a minor volume or a more slender shape and may comprise means for grasping around the intra-articular component to which the device is capable of interlocking.

The forceps may further comprise means for locking the device around or substan- tially around the intra-articular component and optionally means enabling the forceps to be withdrawn without withdrawing the device.

Thus, a further object of the invention relates to a kit comprising:

a) an intra-articular prosthetic device for a joint having

a.1 ) a spacer function and/or capability to exert pressure distribution and/or sliding/rotating movement of the joint by an internal movement of the device by means of a resilient member, and

a.2) a locking mechanism adapted to fix the device to an intra-articular component by means of an element of the device surrounding the component in such a manner that displacement of the device is limited by interlocking with the component; and b) an instrument for inserting the prosthetic device into a joint cavity.

Preferably, the elements of the kit should be sterile.

The instrument b) may further comprise one or more of the following means b.1 to b.4:

b.1 ) means for deforming the prosthetic device into a reduced volume or to a slender shape and keeping this volume or shape upon intro- duction of the device to the joint;

b.2.) means for grasping or encircling the intra-articular component to which the element of the prosthetic device is capable of inter-locking;

b.3.) means for leaving the prosthetic device in the joint with the element of the prosthetic device surrounding an intra-articular component; and

b.4.) means for retracting the instrument from the joint.

It is contemplated that each of the means of b.1.), b.2.), b.3.) and b.4.) may be connected to or form part of a handle. Moreover, the resilient member of a.1 ) and the element surrounding the intra-articular component of a.2) may constitute the prosthetic device.

The means of b.2.) for grasping or encircling the intra-articular component may comprise an incision of the instrument which, in situ, is able to substantially retain the element within the "legs" of the incision.

Biological activity of the device

When inserted in the joint cavity the device is capable of alleviating the pain and other symptoms related to damaged cartilage, such as improving movements. Furthermore, the device may be capable of healing the sick bone's structure and/or cartilage structure- in hole of partly. For example the device may facilitate creation of new cartilage and/or minimise destruction, such as fibrillation and/or fragmentation, of cartilage by relieving the pressure on the residual cartilage/bone in the joint

Furthermore, the device may comprise biological active additives. Medication or biological active substances can be used as additive to the device to facilitate healing, minimise destruction or with other therapeutic goals, such as pain relieve, anti- inflammation, oncology treatments, stimulation of bone growth, and/or anti-infectious agents. Also, biological osteogenic or chondrogenic, chondral inductive, and/or chondral conductive materials may be added to the device. In particular patients suffering from osteoporosis or other bone degenerating conditions may benefit from having devices comprising osteogenic inductive materials implanted.

The device itself can be used as a growth medium and/or network for the natural or artificial cells, such as chondrocytes.

The device is capable of being formed in the production process to suit any joint cavity of animals or human beings, therefore the device may for example be formed to fit into any one of the following joints: Hip joint, knee joint, ankle joints, shoulder joint, elbow joints, wrist, fingers, spinal column joints, such as for substituting intervertebral discs, and the jaw joint.

The important material of the device according to the invention is metal in a form described elsewhere herein. The material for the medical devices may further be polymers, with at least one layer of a first polymeric component with high molecular weight, and at least a layer of a second polymeric component with low molecular weight. This combination of longer and shorter polymers provides the feature of the device comprising strength as measured by tear, tension and compression. These polymers itself may optionally comprise one or more metal components which are described elsewhere herein.

In one embodiment of the invention a medical device comprises a bio-compatible device with a layered structure comprising at least one upper layer of a first polymeric component, a middle layer of a second polymeric component, and at least one lower layer of a third polymeric component, wherein the chain length of the first polymeric component and the third polymeric component is longer than the chain length of the second polymeric component. These polymers may optionally comprise one or more metal components which are described elsewhere.

Another embodiment of the present invention provides for layers of polyolefinic polymers and resins. Within the context of the present invention, a polymer is defined as an organic compound having repeating units of similar or different monomers. A resin is defined herein as a partially cured polymer having utility as a mouldable material suitable for curing into a solid article.

Metal

The metal or metal components e.g. as fibre used in the devices may be any suitable metal which is biocompatible.

In a preferred embodiment the metal component is selected from one or more of the metals steel e.g. stainless steel, titanium, tantalum, gold, silver, chromium-cobaltum, zirconia, cobalt-chromium-molobdenum alloy and/or a ceramic of one or more of these metals and alloys and may be of any structure as described elsewhere herein.

Preferred metals are stainless steel, titanium, gold, silver and/or chromium- cobaltum.

The metal components of the device may be in the form of fibre or filaments, although in this text "fibre" means both fibre and filaments. The metal components may also be in the form of powder, which in this text means powder, pellets, chopped fibres etc.

The Cobalt-Chrome alloys may be with the base metals cobalt and chrome mixed with smaller quantities of other metals.

The amount of cobalt in a cobalt-chrome alloy may be at least 25%, such as at least 30%, such as at least 35%, such as at least 40%, such as at least 45%, such as at least 50%, such as at least 55%, such as at least 60%, such as at least 65%. The amount of chrome in a cobalt-chrome alloy may be at least 10%, such as at least 15%, such as at least 20%, such as at least 25%, such as at least 30%, such as at least 35%, such as at least 40%, such as at least 45%, such as at least 50%, such as at least 55%, such as at least 60%, such as at least 65%.

Any combination of the amounts mentioned above of cobalt and chrome which in total do not exceed 100% may be used as a metal in a device according to the present invention.

Preferred is an alloy with at least 34% cobalt, at least 29% chrome mixed with smaller quantities of other metals. Optionally nickel may be one of the other metals.

Preferred is the alloy named Vitallium e.g. in the combination of 60% cobalt, 20% chromium, 5% molybdenum, and traces of other substances.

Titanium alloys may be used as part of a device, in such alloys the base metal is titanium.

Preferred is a titanium alloy with aluminium. The aluminium amount may be 1-20%, e.g. 1-10 %, such as about 4%.

Stainless Steel alloys may be used as part of a device, in such alloys the base metal is iron, mixed with larger quantities of chrome and nickel and some other metals

Preferred is a stainless steel alloy with iron in an amount of at least 40%, such as at least 50%, such as at least 60%, such as at least 70%.

Preferred is a stainless steel alloy with at least 58% iron, mixed with larger quantities of chrome and nickel and some other metals.

Preferred is the stainless steel of grade 316 e.g. 316L, 316H and/or 316Ti. More preferred is the stainless steel denoted 316L (low carbon). The metal can be used in any form, like powder, granulate, chopped fibres, long fibres, 2D structural components like plates, 3D structural components like shaped plates or hemicircles with holes. Also a combination of these forms may be used.

In different areas of a device different metals and/or different alloys may be used, e.g. in a layered structure comprising three polymer layers each further comprising one or more metal component, each polymer layer may comprise e.g. fibers etc. of different or similar metal or alloys.

Fabric

In a preferred embodiment of the invention the device comprises a fabric, which may be produced from fibres described elsewhere herein e.g. purely of metal fibre, or of metal fibre and polymer fibre, especially UHMWPE fibre.

The device may hereby include fabrics made of metals and/or of polymers or of fabrics made of a combination of fibre of these materials.

One fabric as described herein may constitute the upper and lower layers of a medical device or the entire implant thickness. Thus two or more fabric may be combined to produce a device, although also a single layer of fabric may constitute the medical device.

Methods of construction of polymer and metal fibres are known to persons skilled in the art. The polymers and/or metals may be aligned and/or spun into fibre by gel spinning or filaments, which again may be spun into strands. From the fibres and/or filaments and/or strands the layers of polymeric and/or metallic materials may be manufactured.

Metal fibre may also be treated to produce filaments and/or strands. The methods are known to persons skilled in the art.

Preferred is metal fibre with an average thickness of 0.05 to 0.8 mm, more preferred is a thickness of 0.1 to 0.5 mm, even more preferred is a thickness of about 0.2 to 0.3 mm. When making a fabric with at least one metal fibre of an average as mentioned above, the actual thickness may vary outside of these intervals, e.g. an average thickness of a fibre of 0.2-0.3 mm may actually vary within 0.01 to e.g. 0.6 mm.

The fabric of the invention may be produced into a suitable shape, the shape is preferably constructed by weave, knit, crochet, stitch, plait, interlace, intertwine, interlock, link or unite the fibre and/or filaments and/or strands of polymeric and/or metal fibre in other ways such as non-woven techniques. Preferable the fabric is woven or knitted. A woven fabric compared to some of the other types of fabric has the advantage that the single fibre within the fabric is not bent as much as in e.g. a knitted fabric. Thus the risk that the fibre is broken in the manufacture of the fabric or when the implant is subjected to load in the joint of an individual is reduced when the fabric is woven.

In an embodiment the polymer and/or metal fabric can be woven using one or a combination of different techniques, the techniques include but are not limited to cord woven, linen woven, mat woven, Celtic woven and twill woven. Other possibilities of woven fabrics used for the medical device according to the invention are the weaves denoted plain, rib, twill, panorama, atlas weave, basket weave, double weave, even weave, pile weave, pique weave, plain weave, satin/sateen weave or the like. Persons skilled in the art know variations of these techniques, the variations is hereby incorporated.

Different numbers and orientations of the fibre of the fabric are shown in Fig. 9. In this respect the numbers of fibre is equivalent to the numbers of different orientations although a multiplicity of fibre may be included in each orientation. As shown in Fig. 9, the numbers of orientations may be 2, 3, 4, but may also be higher e.g. 5, 6, 7, 8. Each of the drawings in Fig. 9 is illustrating the texture of a single fabric. One or more of these fabrics can be used for a medical device according to the invention. In Fig. 9 the fibre is illustrated as being of a similar thickness, this is one possibility, although fibre of different material and/or different thickness as described elsewhere herein may be use.

In another preferred embodiment the fibres, filaments or strands of the constitution described above are woven into the fabric in a shape suitable for the shape of the device. The shape of the fabric can be any possible shape including but not limited to round, oval, triangle, quadrangle, square, rectangular, pentagon, hexagonal etc. and may be symmetrical or asymmetrical in any direction. Preferred shapes of the fabric are squared, quadrangle and round.

In an embodiment the polymer and/or metal fabric or fabrics are produced directly into the shape which is to constitute the final device to be inserted into an individual. The size of the fabric may be different than the size of the final device, and the final size may be reached through e.g. a heating process. When more than one layer of a polymer and/or metal fabric are used for a device, these fabrics may each be produced directly into the shape and size which is to constitute the final device although the sizes are different to make it possible to combine the pre-formed fabrics into a layered structure.

In one embodiment the polymer and/or metal fibres in each layer of the fabric are positioned over each other making a structure wherein the angles of the intersect are of 1 to 179 degree, such as in angles of 40 to 150 degree, for example such as in angles of 60 to 130 degree, such as in angles of 70 to 110 degree, for example such as in angles of 80 to 100 degree, such as in angles of about 90 degree with fibre in two orientation. Most preferred is intersects of fibre and strands in angles of about 90 degree with fibre in two orientation, about 60 degree with fibre in three orientations and 45 degree with fibre in four orientations.

The thickness of the fabric is preferably determined by thickness as well as the number of fibres and/or filaments and/or strands and the distance between these fibres, filaments and strands in the fabric. The overall thickness of the fabric is preferably between 0.001 mm and 5 mm, preferred is between 0.01 mm and 4 mm, more preferred is between 0.02 mm and 2.5 mm, further preferred is between 0.03 mm and 1.0 mm, yet further preferred is between 0.04 mm and 0.08 mm, most preferred is between 0.05 mm and 0.06 mm.

In an embodiment the area weight of the fabric is preferred between about 10 g/M² and 500 g/M² preferred is an area weight of between about 50 g/M² and 300 g/M², more preferred is an area weight of between about 75 g/M² and 250 g/M², further preferred is an area weight of between about 100 g/M² and 200 g/M², yet more preferred is an area weight of between about 125 g/M² and 175 g/M², even more preferred is an area weight of between about 140 g/M² and 160 g/M², most preferred is an area weight of about 150 g/M².

In an embodiment the thickness and/or area weight of the fabric varies across a single sheet of fabric. Hereby the area weight of the fabric also varies in the device. The area weight of a single fabric vary at least 5% across the fabric sheet, such as 10%, such as 20%, such as 30%, such as 40%, such as 50%, such as 60%, such as 70%, such as 80%, such as 90%, such as 100%, such as 120%, such as 140%, such as 160%, such as 180%, such as 200%, such as 250%, such as 300%, such as 350%, such as 400%, such as 450%, such as 500% according to the area weight of the thinnest 1 cm² of the fabric.

In an embodiment the thickness of the fabric has a first thickness in the middle area of the device and a second thickness in at least a part of the outer area of the device. The first thickness of the device may be smaller than the second thickness, and can vary as described elsewhere herein. The first thickness may be in the rounded area of a cup-shaped device, whereas the second thickness may be in the skirt i.e. the area close to the edge of a cup-shaped device.

The fibres, filaments and strands from which the fabric is produced according to the description herein, may have a fibre diameter preferably between 100 and 650 dtex. The fibre diameter of the warp yarn is preferably about 300-650 dtex, more preferably about 350-550 dtex, further preferably about 400-500 dtex, most preferably about 430-460 dtex. The weft yarn is preferably about 100-350 dtex, more preferably about 150-300 dtex, further preferably about 175-250 dtex, most preferably about 210-230 dtex.

The fabric need not be constructed of fibre or filaments or strands with equal thickness. A woven fabric where some of the strands have a larger thickness than the rest may be used. In this way e.g. every second, every third or more strands in between may have a larger thickness than the rest of the strands of the fabric.

The fabric described herein may also be constructed by strands of different polymers and/or of different metals or a combination hereof. The different polymers and/or of different metals may be selected among the polymers and metals listed elsewhere herein. Two or more polymers and/or metals may be used in the construction of the fabric.

In an embodiment the thickness of the fabric may vary according to different thickness of the polymer and/or metals strands as described above or different polymers and/or metals may be utilised to construct the fabric. Also different numbers of strands pr cm may be used.

In an embodiment the woven fabric comprises at least one orientation of warp yarn and at least one orientation of weft yarn, each of the weft yarn being passed over and under the at least one warp yarn and/or the others weft yarn in a technique selected from 1 :1 , 1 :2, 1 :3, 1 :4, 1 :5, 2:2, 2:3, 2:4, 2:5, 3:3, 3:4, 3:5, 4:4, 5:5 or the opposite in respect of passing the weft yarn over and under the other yarns. Preferred is a twill weave with fibre in 2 or 3 orientations and with a weaving technique of 1 : 1 , 2:2, 3:3, 4:4, 5:5, 6:6, 7:7 and any possible combination thereoff like 1:5, 4:7, 2:4 etc.

In a preferred embodiment the warp yarn may have an average thickness which is larger than the average thickness of the weft yarn. The warp yarn being at least 5% thicker, such as at least 10%, 15%, 20%, 25%, 30%, 40%, 50%.

According to an embodiment of the invention the polymer and/or metal fibres are woven into a squared fabric comprising intercepts with angles of about 90 degree. The dimension and weaving style of the fabric is optional, preferred is a binding style of 3:1 (twill). The fabric can if the thickness and material allows it be rolled into a roll, from which suitable pieces are detached before a product is constructed. Polymeric products which can be used comprises but is not limited to fabric of Dyneema® from DSM, Spectra® from Allied Signal Inc. Preferably the fabric is workable in the process of construction of the medical device as described elsewhere herein.

In a preferred embodiment 3 orientations of fibres may exist in the fabric used for the device. The angle between two fibre of different orientation is about 60° although this may vary e.g. between 50-70°. The fibre may be of similar thickness or fibre in one orientation is thicker that the fibre in the two other orientations, which again may be of similar thickness or of different thickness. The thickness is an average thickness and may vary as described elsewhere. When weaving the one direction of fibre is the warp yarn/thread, the other two directions are weft yarn. The weft yarn is passed over two or three warp thread and then under one warp threads, over two or three and under one, and so on. There may be a "step" or offset between rows which creates a characteristic diagonal pattern of the fabric.

Fabrics may be produced as Square Mesh, Plain Dutch Weave, Reverse Plain Dutch Weave, PZ-Microdur, KPZ-Microdur, Multiplex Meshes with 2, 3, 4 or more fibre in a bundle, TELA Mesh. Any material mentioned herein may be used for the weaving types mentioned. A preferred fabric for the implant is a Twilled Dutch Weave (In German: "Kδpertressengewebe") and is a twill weave with fibre in three orientations. Even though only one layer of fibers are used for each orientation, the weaving structure makes the fabric looks as if more than one layer of fibre is used.

The woven fabric of the present invention may be woven such that the fibre in one predetermined orientation is located only in one layer. Also the number of fiber layers having the same orientation in one fabric may be above 1 , e.g. 2, 3, 4, 5. The number of fiber layers can be different within the different orientations of fibre, one orientation may include 1 layer of fibre, another orientation 2 layers etc. Preferred number of fiber layers within a woven fabric are (the number of values indicate the number of orientations): 1-1 ; 1-1-1 , 1-1-1-1 , 1-1-1-1-1 , 1-2, 2-2, 1-1-2, 1-2-2, 2-2-2, 1-1-1-2, 1-1-2-2, 1-2-2-2, 2-2-2-2, 1-3, 2-3, 3-3, 1-1-3, 1-3-3, 3-3-3, 1-2-3, 2-2-3, 2-3- 3, 3-3-3, 1-1-1-3, 1-1-3-3, 1-3-3-3, 3-3-3-3, 1-1-2-3, 1-2-2-3, 2-2-2-3, 1-2-3-3, 2-2-3- 3, 2-3-3-3, 3-3-3-3.

In an embodiment the surface dimension of one or more inner layers of fabric may be smaller than the total surface dimension of a medical device. Smaller layers of fabric may enclose inlays of polymer and/or metal.

In another preferred embodiment the fabric has a high tensile strength and a high wear resistance. The degree of tensile strength is determined by the polymer utilised to produce the fibre and the thickness of the fibre. The tensile strength of the strand or fibre in a fabric is preferably above 1.0 GPa, such as above 1.2 GPa, preferable above 1.4 GPa, more preferable above 1.6 GPa, further preferable above 1.8 GPa, yet further preferable above 1.9 GPa, most preferable above 2.0 GPa.

In another embodiment the tensile strength of the strand or fibre in a fabric is preferably above 0.05 GPa, such as above 0.1 GPa, preferable above 0.3 GPa, more preferable above 0.5 GPa, further preferable above 0.7 GPa, yet further preferable above 0.8 GPa, most preferable above 0.9 GPa.

Although the term 'fibre' is used in the description of fabric, filaments and/or strands and/or other components comprising long chains of polymer units or of metal may be used instead of fibres.

One or more fabrics may constitutes a reinforcement fabric or tissue of the device.

Features of the product

The thickness of the product may be determined by the number of fabrics and the dimension of these fabrics in accordance to the requirements of the medical device. The total thickness of the device is preferably between 0.001 and 40 cm, such as between 0.005 and 30 cm, preferable between 0.01 and 20 cm, more preferable between 0.02 and 10 cm, further preferable between 0.03 and 8 cm, yet further preferable between 0.04 and 5 cm, most preferable between 0.05 and 2 cm.

In another embodiment the preferred thickness of a device is about 3 mm, such as about 2.5 mm, e.g. about 2 mm, such as about 1.5 mm, e.g. about 1 mm, such as about 0.5 mm, e.g. about 0.4 mm, e.g. about 0.3 mm, e.g. about 0.2 mm. This may be an average thickness of the device.

In a preferred embodiment the thickness described above is the preferred thickness of the device in the area where the device is located between two bones of a joint. In the other area the device may be thicker, such as at least 10% thicker, at least 20%, at least 30%, at least 40%, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, at least 100%, at least 150%, at least 200%, at least 250%. The device may have any suitable shapes, e.g. cup-shaped or approximately cup- shaped, and wherein a middle area is the top and an outer area is a skirt. The skirt may be thicker that the middle of the top. In a preferred embodiment the thickness of the cup-shaped device is about 0.5 mm in the middle area at the top and about 1 mm in the skirt e.g. in the outer edge of the skirt.

The surface area of a medical device may be between 1 cm² and 200 cm².

The surface dimension of a medical device comprising the fabric as described herein may be between 0.01 to 40 cm according to length and width, such as between 0.05 to 35 cm, for example between 0.09 to 30 cm, preferable between 0.1 to 25 cm, more preferable between 0.2 to 23 cm, further preferable between 0.3 to 19 cm, yet further preferable between 0.4 to 17 cm, most preferable between 0.5 to 15 cm. Other preferred sizes of the surface dimension of a medical device may be between 0.5 to 8 cm according to length and width, such as between 0.5 to 7 cm, for example between 0.5 to 6 cm, preferable between 0.5 to 5 cm, more preferable between 0.5 to 4 cm, further preferable between 0.5 to 3 cm, yet further preferable between 0.5 to 2 cm, most preferable between 0.5 to 1 cm.

The surface dimension according to length and width of layers of fabric in a medical device as described herein may be substantially equal, equal or different from the surface dimension of the medical device. Preferred is a size where any surplus of fabric is removed following or during manufacture of the medical device.

In an embodiment the medical device is a flexible device comprising metal. In this context flexible means that the device ready for implantation can be resilent when performing a pressure by human hands, but the medical device can not be reshaped or deformed when performed to the normal pressure of human hands.

In another embodiment the medical device can be flexible such that it can be deformed by the bone of a joint when located within an individual. By this deformation in situ the device becomes shaped according to the requirement of the bone shape of the individual i.e. a self-adaptation occurs.. When the device is produced from at least two fabrics, it may further comprises at least one inlay, core or film as described below to be positioned between two of the at least two fabrics. Film, core or inlay may be of any metal and/or polymeric material described herein.

The differences of film, core and inlay may be the dimensions of the metal and/or polymer layers. The dimensions are determined according to the function of the layers. The film, core and inlay may differ in thickness from each other, but may also have similar thickness, whereby film and core sometimes can substitute each other in the composition of the medical device.

The visual difference of film and core is preferably based on the thickness, where the film in general is thinner than the core. The main purpose of a film layer is to attach two layers of fabric to each other, and simultaneously provide the device with characteristics such as capability of absorbing shocks, impacts and pressure load.

The core may also attach fabrics to each other, and provide the same characteristics to the device as the film, but the core may be utilised in devises subjected to higher degree of impacts and pressure load than to devises comprising no core layer.

The difference of core and inlay may be based on the length and width of the layers, the inlay may be smaller than a core. The function of an inlay is to absorb shocks and pressure in specific areas of a medical device. An inlay of one device may be larger than a core of another device.

To enclose one or more inlays with fabrics, the size of fabric according to the surface dimensions length and width may be the same as for the inlay, substantially the same as for the inlay or somewhat larger than the inlay. One or more inlays may be enclosed by two or more layers of fabric. The layers of fabric may have surface dimensions adjusted to cover all the inlays, although the inlays may have distance between each other. Two or more inlays of a device may or may not be positioned in between the same two layers of fabric. The surface dimension according to length and width of layers of film in a medical device as described herein may be substantially equal, equal or different from the surface dimension of the medical device. Preferred is a size where any surplus of fabric is removed followed manufacture of the medical device.

The surface dimension according to length and width of layers of core in a medical device as described herein may be substantially equal, equal or different from the surface dimension of the medical device. Preferred is a size substantially equal to the surface dimension of the medical device.

The surface dimension according to length and width of layers of inlay in a medical device as described herein may be substantially equal, equal or different from the surface dimension of the medical device. Preferred is a size where the inlay is smaller than the surface dimension of the manufactured medical device.

To increase the strength of the device, the layers of fabric may be turned according to each other, hereby the fibres of the different layers of fabric are positioned into different directions. The fabric may be turned between about 0 to about 90 degree, such as between 10 and 80 degree, preferred is between 20 and 70 degree, more preferred is between 30 and 60 degree, further preferred is between 38 and 52 degree, yet further preferred is between 42 and 48 degree, most preferred is about 45 degree in relation to the former and/or next layer of fabric.

In an embodiment at least part of the polymeric component or polymeric compo- nents optionally comprising one or more metal components, of the device, is suitable for cells to grow into it. Preferred is when the surface of the device is in a condition suitable for cells to enter and grow into this surface. This in-growth of cells secure the device within the joint of the mammal. Medical devices made partly or entirely of metal may also comprise a material suitable for cell in-growth or the device may be itself be suitable for cell in-growth.

The medical device may be secured with a collar and can be of any design and construction as mentioned elsewhere herein. The medical device of the present invention is preferably a cartilage implant, but may also be an implant used as in a femoral head implant and/or an acetabular cup implant. When used as an acetabular cup implant the device may have securing means to secure the acetabular cup in the pelvis. Securing means are known in the art.

It is preferred that the when the device is a cartilage implant or a spacer/liner of a partial or total joint implant e.g. at hip joint implant, the device does not have any securing means. Hereby the device can rotate freely within the joint.

Shaping the medical device

The material making up an implant may be subjected to pressure and may be pushed or pressed into a mould to form the device. Optionally the pressing process is combined with a heating or cooling process.

To secure the desired shape of a device, the pressure of the device in the shaping process may be maintained until the metal and/or polymer product is cooled preferable to room temperature. This cooling under pressure secures consolidation of the product.

The pressure in the process described above is a pressure high enough to press the product into a mould, the pressure may be a low pressure performed for a long period or a high pressure performed for a short period, or a pressure in between. Low pressure in this context is the pressure just enough to press the product into a mould.

The temperature when subjecting the material to heating when pressing the device, should be below the melting temperature of at least one of the material making up the device. Thus the temperature is determined according to the type of the material and of the intended structure of the formed product.

In a medical device comprising different polymers and/or metal, the temperature may be chosen to melt the material(s) with the lowest melting temperature hereby this material(s) may adhere to the other material and be positioned within the structures of the other types of material.

When the medical device is constructed of only metal, the device can be produced due to a method comprising pressing the material into a suitable shape optionally by using vacuum and/or increased temperature, the shaped device is subjected to a soaking process comprising heating the device to a temperature just below the melting temperature of the metal or of one of the metal used for the device hereby making the device red heated, and cooling down the device again. By this process the original crystal structure of the material before subjecting the device to pressing is partly or totally reconstructed.

The medical device made of the material described elsewhere herein can be pressed into any shape as described elsewhere herein, preferred is a cup- or cap- shaped device. In the Figures presented herein the cup-shaped device is indicated to be circular when looking into the device. The device may also be of other shapes e.g. oval, saddle shaped or any form in between. When the term "cup-shaped" is used herein this is not restricted to a circular form, but also includes the other forms between circular and squared.

In a preferred embodiment the medical device according to the present invention is individually adjusted to the individual to undergo surgery i.e. the medical device is customized or custom-made. The individual adjustment may be based on a measurement with or without performing any surgical procedure to the individual. Preferred is when the customization is performed without a surgical intervention. Any non-surgical method resulting in obtaining data of the shape in 2 or 3 dimensions (2D or 3D) of the femoral head and/or of the acetabular cup of the pelvis can be used. Such method may include a photographic and/or scanning procedure e.g. traditional imaging/scanning, CT-imaging/scanning, X-ray imaging/scanning, ultrasound imaging/scanning, MRI imaging/scanning.

A customized implant comprising fibre or not comprising fibre may be shaped with or without the ridges of the natural femoral head. A customized implant comprising fibre in a fabric may be shaped without the ridges of the natural femoral head, although the implant may have a flexibility which allow the implant to be deformed by the hip joint to adapt the implant to the shape of the femoral head..

The invention is also directed to a method of customization of the medical device described herein, the method comprises an individually imaging/scanning of the joint to be subjected to surgery before performing this surgery, manufacture of the medical device according to the present invention, and optionally insertion the medical device into the joint of the individual.

The metal and/or polymer product pressed into a shape as described above, may be stored at room temperature for long periods of time, such as several years.

In an embodiment the device made of a polymeric and/or metal material may be produced with one or more apertures, holes, gaps, perforations or hollows. The apertures etc. may constitute an improved attachment and/or optimise the function of the device. The improved attachment may be obtained without further processing as the apertures may constitute a shape of the device in a way that the device better fits into the location of the body. The apertures can also be utilised to fasten the device within the body.

In an embodiment a medical device comprises one or more apertures, these apertures are each of an overall size (diameter) of at least 1 cm, although the apertures need not be circular, but may have other dimensions such as oval. The overall size of an aperture, calculated as an average diameter, may be of about 1 cm, such as about 1.5 cm, e.g. about 2 cm, such as about 2.5 cm, e.g. about 3 cm, such as about 3.5 cm, e.g. about 4 cm, such as about 4.5 cm, e.g. about 5 cm. The apertures may fit to the protrusion of a bone of an individual such that the protrusion partly or substantially fully fill the aperture of the device.

In a preferred embodiment the medical device is a cup-shaped device with one or more apertures, this device is not locked or physically attached to an acetabular cup or to a femoral stem, although being in contact with the natural and/or prosthetic cup and stem. The cup-shaped device may hereby move freely within the joint independently of the movement of the acetabular cup and femoral stem. The cup- shaped device may be of at least one fabric as described herein or may be manufactured by a moulding process with a material described elsewhere herein, also a reinforced material may constitute the device. Preferably the medical device of this type has one or two apertures, preferably one, with a diameter of about 3 cm. The device may be customized as described elsewhere herein.

Fastening methods are known to persons skilled in the art, and are hereby incorporated.

The apertures etc. may be created simultaneously with the shaping of the device, hereby the mould has points, tips, peaks or other means, which create the apertures in the device. Another method of producing apertures etc. is to make a hole by a drill or another boring, cutting or pressing apparatus. Following the formation of apertures etc. by drilling, cutting or pressing holes, the edge of the apertures on the device may be closed e.g. by a heating process or by positioning a collar on the edge. Collars are described elsewhere herein.

To the metallic and/or polymeric material making up a device, may be attached a component, the component being polymeric and/or non-polymeric e.g of metal. The attachment may constitute part of a prosthesis or provide an anchorage point.

The medical device with the shape described elsewhere herein can have of any design and construction and be of any material as mentioned elsewhere herein.

In an embodiment the metallic material of the medical device does not have an overall shape including a waveform, such that e.g. the metal fibre at least in one direction forms ridges and grooves.

Composition of devices

The device according to the invention may be layered only with polymer layers optionally comprising one or more metal components, or a combination of metal layers together with polymer layers optionally comprising one or more metal components, or with layers/fabrics entirely made of metal. In an embodiment the number of layers of polymer optionally comprising one or more metal components may be similar to or lower than the number of layers of metal. The composition of a device may be according to the following list, where polymer means a polymer layer optionally comprising one or more metal compo- nents. The list is not exhaustive:

• metal - polymer

• metal - polymer - metal

• metal - polymer - polymer - metal

• metal - polymer - metal - polymer - metal • metal - polymer - metal - polymer - polymer - metal

• metal - metal

• metal

• metal - metal - polymer

• metal - metal - polymer - polymer • metal - metal - polymer - metal

• metal - metal - polymer - polymer - metal

• metal - metal - polymer - metal - metal

• metal - metal - metal

The list does not indicate the orientation in respect of outer and inner or upper and lower layer of the device. In a device with two or more polymer layers, these layers can be of a similar composition or be different in composition. In a device with two or more metal layers, these layers can be of a similar composition or be different in composition.

In a device which comprises one or more layers of metal located next to each other the metal layers may be only soft metals, only hard metals or a combination of soft and hard metals.

In an embodiment the number of layers/fabrics of polymer optionally comprising one or more metal components may be similar to or higher than the number of layers/fabrics of metal. The composition may be according to the following list, where polymer means a polymer layer optionally comprising one or more metal components. The list is not exhaustive:

• polymer - polymer • polymer - metal • polymer - metal - polymer

• polymer - metal - metal - polymer

• polymer - polymer - metal - polymer

• polymer - polymer - metal - polymer - polymer • polymer - metal - polymer - metal - polymer

• polymer - polymer - polymer

Devices produced from layered structures may be any devices as mentioned elsewhere herein.

In an aspect of the invention the prosthetic device is not a layered product, or not produced from layers and/or fabrics of polymer and/or metal. The device may be produced from on single polymer product optionally further comprising one or more metal components or may be produced entirely or substantially entirely from one type of metal or metal alloy.

In a device with a non-layered structure different areas of the device may be made from two or more polymer.

In an embodiment the device is made of a polymer and/or metal which is suitable of injection moulding, to the polymer may be added one or more types of metal fibre and/or metal powder. Optionally also polymer fibre can be added. Preferably the polymer which is suitable of injection moulding is one or more polyolefin. More preferred the polymer is polyethylene and/or polypropylene. Preferably the metal is se- lected from titanium, gold, silver and/or chromium/cobaltum.

In an embodiment the device is produced by shaping a polymeric and/or metallic material comprising fibre and/or powder of metal, optionally polymer fibre may also be added to the polymer. The shaping may be performed by injection moulding.

In an embodiment, a device, e.g. an acetabular cup or an interpositional arthroplasty can be made of polymer and/or metal which is suitable of injection moulding, to the polymer may be added one or more types of metal fibre and/or metal powder. Optionally also polymer fibre can be added. Preferably the polymer which is suitable of injection moulding is one or more polyolefin. More preferred the polymer is polyeth- ylene and/or polypropylene. Preferably the metal is selected from titanium, gold, silver and/or chromium/cobaltum.

In another embodiment, a device, e.g. an acetabular cup or an interpositional ar- throplasty can be made of a 3D network or a mat of metal fibre and/or polymer fibre. The mat can be filled with a polymer with a lower melting point than the polymer fibre and the device can be subjected to heat and pressure to produce a device comprising fibre of metal and/or polymer fibre in a matrix of polymer.

The 3D-network may have a knitted, crochet and/or weaved structure, or a structure described elsewhere herein.

The metal to be used in the 3D-network may be any suitable metal. Preferred is a metal selected from titanium, gold, silver and/or chromium/cobaltum.

The polymer fibre to be used in the 3D-network may be fibre of any polymer described elsewhere herein. Preferred is a polymer fibre of polyethylene or polypropylene. More preferred is UHMWPE.

Devices produced without a layered internal structure or without laying layers towards each other in the production process may be any devices as mentioned elsewhere herein.

Collar

Following or during the shaping of the device as described elsewhere herein, any surplus of polymeric and/or metallic material can be removed e.g. by cutting off. Cutting off the surplus of polymeric and/or metallic material leaves a device with right angle edges. These edges have to be rounded to secure no damage is performed by the product within the animal or human body when positioned within the body of an individual.

In an embodiment the rim of the device and/or of apertures may be treated to fix loose ends of fibre or strands. The rim may be closed by sewing or by fastening a polymer ring or a metal ring or a ring of polymer and metal. When using a ring to close the rim of the device, the ring may be 0.5-5 mm thick, preferred is about 3 mm.

In another embodiment a collar is placed on the medical device when surplus of material is removed. The collar can be moulded directly on the device e.g. by injection moulding. The collar may be of any polymeric and/or metallic material described elsewhere herein.

In another embodiment a collar is moulded before positioned onto the edge or edges of the device. Preferred is when the collar is injection moulded. The collar can be secured to the device by heating, ultrasound welding, gluing, sewing and/or laser welding.

The collar as described above can be of any material mentioned in the description of the a metallic and/or polymeric component. The collar material of the medical device can be the same material or a different material as actually used for the rest of the device or for a part of the rest of the device. Preferred is when the collar includes fibre e.g. of UHWMPE or LDPE. More preferred is collar of LDPE. Preferred is also when the collar includes nano-structured composite of polymer and/or metal. Further preferred is when the collar includes short and long composite of polymer and/or metal. Most preferred is when the collar is produced of the same polymeric component optionally comprising one or more metal components as actually used for the core or film, due to compatibility between the materials. Within the production process the polymeric and/or metallic component of the collar may melt together with the polymeric and/or metallic component of the film and/or core. Also preferred is when the collar material includes nano-fibre or short fibre of polymers and/or metals.

In an embodiment a cup shaped medical device is produced, where a hat brim of surplus of material is removed and a pre-moulded collar of LDPE optionally comprising one or more metal components is attached on the cut edges.

The collar closes the edge, gives the cup strength, and may include or support one or more markers e.g. in the form of a gold thread. Furthermore the collar modifies the friction. Instead of mounting a collar on the edge of the device, it is possible to bead or flange the edge or edges. This treatment can be performed under heat.

A collar that is pre-moulded before mounted to the edges of a medical device is easier to handle, and has economical benefits compared to injection moulding a collar onto the edges.

It can be difficult to mould a collar directly on the medical device, as the device may become soft at the temperature and pressure at which the collar is injection moulded onto the edge of the device. Hereby there is a risk of deformation of the outer area of the device. With a pre-moulded collar , the collar can be attached to the edge by ultrasound welding, gluing, sewing and/or laser welding the edge and the outer area of the device is not at risk of the mentioned deformation.

The methods of fastening the pre-moulded collar to the medical device secure a safer attachment between the collar and the edge and the outermost part of the outer area of the device. The material of the collar may adhere to the polymeric and/or metallic material of the device, the polymeric materials optionally further comprise one or more metal components. Preferred is ultrasound welding to attaching the pre-moulded collar to the medical device.

The pre-moulded collar has a dimension that secure that the collar when attached to the medical device covers at least 0.5 mm of the outer area of the upper surface when measured from the edge. A similar dimension may be covered at the lower surface of the device. The collar need not cover equal dimensions of the upper and lower surface.

In an embodiment the pre-moulded collar has a groove wherein the marker can be placed. Preferred is an inner groove. Hereby the marker may be located at the edge of the device and the collar encloses or support the marker Preferred is a marker in the form of a thread or wire of metal.

The marker can be in the form of one single unit or in the form of at least two units, and where the at least two units are placed non-homogeneous within the device. Hereby the rotation of the device within the joint can be detected as described elsewhere herein.

In an embodiment the collar includes and/or supports at least one marker. These markers are described herein below. By including these markers in the collar there is no need of placing marking particles in holes of the device. Thus the incorporating of a marker in or supported by the collar eliminates the step of drilling in the device.

In a preferred embodiment a cup-shaped or approximately cup-shaped medical device has a top and a skirt with a thickness larger than the thickness of the top, and where the edge of the skirt is enclosed by a pre-moulded collar. The collar can include a marker as described elsewhere herein.

Collars as described herein may be use for a medical device of any design and con- struction as mentioned elsewhere herein.

Smoothness of the surface

The smoothness of the surface of the device is important as this has a connection with the level of pain as well as a connection with pain relief of the mammal in whom a medical device is located within a joint.

In an aspect of the invention the medical device comprising at least a first and a second side, wherein the at least first side is made of a metal and/or first polymeric component, and wherein the first and/or second side has a frictional resistance of less than 10 Newton. Preferred is less than 1 ,0 Newton, e.g. less than 0.5 Newton, such as less than 0.3 Newton. More preferred is less than 0.2 Newton, e.g. less than 0.1 Newton, such as about 0.

The roughness of the fiber material of the medical implant or of the implant ready to be positioned in an individual is preferably less than 1 μm. Preferred is less than 0.5 μm, e.g. less than 0.4 μm, such as less than 0.3 μm. More preferred is less than 0.2 μm, e.g. less than 0.1 μm, such as about 0. The values given above in respect of friction resistance and roughness of single fibre or the entire medical implant can be combined in any combination.

The device becomes more smooth when located in a joint and this joint is in func- tion. The surface of the device will be exposed to some wear, hereby the surface becomes more smooth. By producing a device which when implanted is more smooth than normal, pain relief of the individual wherein the device is implanted is obtained faster.

In an embodiment the polymeric component optionally comprising metal has a fric- tional resistance of less than 0.5 Newton and the polymeric component is located in at least a first area where the device is subjected to wear when the device has been implanted into an individual.

In an embodiment the wear in the at least first area is due to friction made by a bone and/or a medical device.

In a joint in movement, the areas of the device which is always subjected to contact with a bone or another part of an implant is subjected to most wear.

In an embodiment the second side is made of a polymeric component similar to or different from the material making up the first side. The polymeric material may include metal. The polymeric component of this second side may have a similar or another smoothness as the component of the first side.

The surface of the device can be made more smooth by moulding pressing the device an extra time in succession to the preparation of the device. Another method to improve the smoothness is to rub the device for a duration which is suitable to obtain a desired smoothness.

In an embodiment the first and/or second side further includes at least one cavity. The at least one cavity may have a diameter of at least 0.05 mm when measured at the outside of the first side. The cavities of the device provide more space for liquids such as synovial fluid, physiological salt solution or another biocompatible liquid. Hereby is the friction coefficient lowered, the wear is lowered, a lesser degree of pain is obtained by the mammal wearing the device and the durability of the device is increased.

In an embodiment the at least one cavity has a depth of at least 0.01 mm.

The cavities may be in the form of grooves. These grooves may be in straight lines or in patterns e.g. waving lines or zigzag lines.

In one embodiment a device has a smooth surface together with cavities. Especially the surface is smooth between the cavities in the areas which is subjected to wear in the joint. Preferred is a cup-shaped device with a smooth surface and cavities.

The medical device with the smoothness and cavities as described can have any design and construction and be of any material as mentioned elsewhere herein.

Perforations

Medical devices with perforations or apertures provokes an increased flow of liquids such as synovial fluid within the joint.

In an aspect of the invention a medical device comprising at least a first polymeric and/or metallic component, wherein the device has at least one through-going perfo- ration which is not for ligaments.

In an embodiment the at least one perforation has a diameter of at least 0.01 mm.

In an embodiment the at least one perforation is located in at least one area where the device is subjected to wear.

In an embodiment the perforations are located homogeneous over substantially the entire device. In an embodiment the perforations can conduct liquid from a first side of the device to a second side of the device and/or from the second side to the first side. Hereby the liquid can be displaced within the joint in respect of the movement of the joint.

The liquid may be synovial fluid or physiological salt solution or another biocompatible liquid.

In an embodiment the device further comprises an inner volume between the first and second side and inside this inner volume the liquid can be within.

This inner volume may be an empty volume when the device is inserted into the joint. Liquid within the joint can enter this volume. The volume can also include liquid when inserted into the joint or be filled after it is inserted. Hereby the inner volume comprises a storage of liquid.

The inner volume can comprise a network of at least one polymeric and/or metallic component. The polymeric component can be polymeric fibres and the metal components can be metal fibre, where the empty space constitute space for liquid as described above.

The medical device with the perforation and/or inner volume as described can have any design and construction and be of any material as mentioned elsewhere herein.

Two congruent cups

In another aspect of the invention a medical device comprises at least a first unit with at least a convex surface and a second unit with at least a concave surface, where the convex and concave surface is congruent with each other and the first unit fit partially or entirely into the second unit, and wherein the first and/or second unit comprises at least one polymeric and/or metallic component.

In an embodiment the first and second units have substantially similar size.

In an embodiment the first and second units have different sizes. In an embodiment the first and second units are connected or substantially connected by the convex and concave surface. Hereby the one unit fits into the other unit. The concave surface can be at least 0.01 mm smaller than the convex surface.

In an embodiment the units are movable compared to each other, and the units continue to be in contact during a movement and/or return to be in contact when a movement is finished. The first unit and/or the second unit may be attached to an implant and/or a bone.

In an embodiment the first unit and/or the second unit can function without being attached to an implant and/or a bone.

In one embodiment the two units are two cup-shaped units, which are secured or attached to a bone or implant or located at a bone or implant or within a cavity. Be- tween these cups may be located gas in the form of air, liquid such as synovial fluid or a physiological salt solution or another biocompatible liquid.

The medical device with the two units, one with a convex surface and the other with a concave surface as described can have any design and construction and be of any material as mentioned elsewhere herein.

Strengthening implants with fabric

In an aspect of the invention a medical device comprises at least a first surface area, wherein at least a first polymeric and/or metallic component is attached to the first surface area. The device may at least in the first area be subjected to wear when the device is located in a mammal individual.

In an embodiment the device is made of polymer and/or bone and/or metal. The first polymeric and/or metallic component may constitute at least 1 % of the surface of the device.

In an embodiment the first polymeric and/or metallic component may be located at the outside of the device in areas that is subjected to wear. The first polymeric and/or metallic component can be in the form of a fabric. The fabric can be made by weaving, knitting and/or crocheting. Fabrics as described elsewhere herein may be used.

One or more layers of fabric can be attached to the first surface area. These layers of fabric can be connected by a second polymeric and/or metallic material which is similar to or different from the layer or fabric, the second polymeric and/or metallic material can be in the form of a film or core as described elsewhere herein. The fabric may be suitable for in-growth of cells

In an embodiment the at least first polymeric and/or metallic component further is placed onto the device in areas that is subjected to a less amount of wear and/or is not subjected to wear.

Preferred is a hip-joint prosthetic device in which the acetabular cup and/or a spacer to be located between the acetabular cup and the femoral head is fabricated from a multiplicity of layers of fabric according to the present invention. The number of layers can be between 2 and 100, preferred is between 3 and 50, also preferred is between 4 and 25, more preferred is between 5 and 15. The layers of fabric may be connected by film or core as mentioned elsewhere herein. The layers of fabric may be of different structure in respect of fibre thickness and e.g. weaving-method, and may also be made of different polymeric and/or metallic materials. The cup may be manufactured in a composite structure, or individually layers of fabric may have a composite structure.

The medical device which is strengthened with a fabric and the fabric used to strengthened the device can have any design and construction and be of any material as mentioned elsewhere herein.

Surface coating

The surface of the device can subsequently be treated to modify surface properties such as wetting ability and/or biocompatibility. This surface treatment can be performed by plasma treatment, chemical grafting or by a combination of plasma polymerisation and chemical grafting. The material contacting with the biological sur- faces may be smooth, biocompatible, preferably self-lubricating, and it should be wear-resistant so that particles generated due to wear are avoided in that this could otherwise result in foreign body reactions and cause further trouble to the function of the part of organism where the medical device is located.

Furthermore, the surface material should preferably be a material or a combination of materials having self-repairing properties so that fissures, cracks or other ruptures on the surface do not exceed uncontrollable levels. However, the surface material is preferably continuous with the material of the rest of the device, e.g. the material may gradually merge into the material of the fabric, film or core of the device. In this context continuous means that the surface material cannot be pulled away from the material beneath.

Without being bound by theory it is also believed that a wetted surface reduces the risk of having the immune system recognising the device when implanted, which would otherwise lead to adverse effects of the device.

In one embodiment the surface of the device may be coated by a plasma polymeri- sation, using low-power plasma equipment. The monomers used for the plasma polymerisation are any monomer forming a hydrophilic polymer by plasma polymerisation. Preferred are monomers forming polyvinylpyrrolidone and poly-ethylene- glycol like polymers, most preferred is 1-vinyl-2-pyrrolidinone.

The surface coating performed as described above has a thickness of 1 to 700 nm, such as between 10 and 500 nm, preferable between 20 and 400 nm, more preferable between 30 and 300 nm, further preferable between 40 and 200 nm, yet further preferable between 50 and 100 nm, most preferable between 60 and 90 nm. In another embodiment the surface coating performed as described above has a thickness of 1 nm to 5,000 nm, such as between 5 and 2,500 nm, preferable between 10 and 1000 nm, more preferable between 30 and 500 nm, further preferable between 40 and 400 nm, yet further preferable between 45 and 300 nm, most pref- erable between 50 and 250 nm.

Plasma is ionised gas. In an artificial plasma to be used for plasma treatment and plasma polymerisation, the concentration of ionised species is preferably 0.1-10 ppm. Two phases exists in artificial plasma: A gas-phase comprising an energi cor- responding to the surrounding temperature, usually room temperature. In a plasma- phase ions and electrons have an energi at approximately 2-10 eV.

The artificial plasma may be established by exposing a gas with electric field. The pressure of the gas is preferably 0.01-1 mbar. The electric voltage utilised is de- pendent of different features such as the pressure, the composition of the gas, electrode configuration, the size of the polymerisation chamber, and frequencies of the electricity. The voltage is typically 200-10,00OV.

In a preferred embodiment of the plasma polymerisation 1-vinyl-2-pyrrolidinone (VP) may be polymerised to polyvinylpyrrolidone (PVP) in a plasma with low energi. The plasma functions as an initiator for the polymerisation by formation of radicals in the surface of the element to be coated. From the radicals the polymerisation process takes place where monomers of VP polymerise to PVP. A low energy is necessary not to destroy the monomer VP in the gas-phase as well as the polymerised PVP. In a preferred embodiment the energy is 0.1-1 W/L.

In the plasma polymerisation treatment a carrier gas is used, preferred is an inert gas, such as argon or helium.

The chamber for performing the plasma treatment is constructed to perform a homogeneous surface coating of the device by the plasma polymerisation process.

The surface coated device is preferably sterilised by radiation or by heating. The radiation can be but is not limited to high-energy electrons, gamma rays, photons, microwaves. The device may by cross-linked and sterilised simultaneously by treating with ionizing radiation or by heating. Preferred is cross-linking by radiation.

Devices

One preferred device produced of the product described herein may be a substitution for cartilage. The cartilage substitution may replace damaged cartilage between intact bones, or it may be part of a medical prosthesis comprising cartilage substitu- tion.

In a preferred embodiment the device according to the present invention has physical properties making the device more rigid and hard than the surrounding components of the joint where the medical device is to be implanted.

A device produced of the product itself can be used as a growth medium and/or network for the natural or artificial cells, such as chondrocytes.

In a preferred embodiment the medical device according to the present invention is a loose device i.e. not attached to any components in the joint. As a loose device, the device is allowed to rotate within the joint of an individual.

A device made from the product optionally comprising one or more metal components as described above is capable of being formed to suit into parts of the organ- ism as described elsewhere herein. Especially the device is suitable to be used in animals, such as mammals and human beings, preferred is human beings. The animals, to which the medical device may be utilised, may be selected from the group of mammals, such as but not limited to horses, dogs, cats, cows and monkeys.

In one embodiment the device is especially constructed to be utilised to support, hold, sustain, bear, carry, replace or displace any constitution within the mammalian body, which comprises high shape stability and good wear resistance. The product optionally comprising one or more metal components is adapted not to interfere with intra-articular or other components when the device is in the body of a human.

The device as medical device may be but is not limited to be used as joint spacer implant in joints of knees, hip, shoulders, fingers, wrist, elbow, spine, neck, loin, toes and ankles. Especially the devices may be used in diseased patients with os- teoarthritic degeneration of joints. The implants with a smooth articulating surface oppose the diseased and degenerated cartilage joint facet, which is expected to lead to reduced force and stresses and improved mobility in the joint with consequent reduced pain and improved functional capacity of that joint.

The medical device as described herein may be produced in a number of sizes corresponding to the natural variety of the bones within the joint where it is intended to be used as well as to the differences in bone size due to the age or size of individuals.

Moreover, non-interference of the intra-articular components may be achieved by a hole which runs through the body of the device; that is to say the device may com- prise a hole through which intra-articular components may pass. When loading the device, the slits may serve to pass intra-articular components through the body of the device. The slits in this embodiment run from the periphery of the body of the device to the hole through which the intra-articular components pass after the device is implanted or loaded.

Typically, and to at least some extent, the device is adapted in its structure and/or material composition to alleviate conditions associated with worn cartilage by providing a spacer function and/or to exert pressure distribution in the joint when the joint is loaded and/or to provide at least part of the sliding/rotating movement of the joint by internal movement of at least part of the device.

It is also an object of the present invention to provide a method for non-invasive locking of a device within a joint. In addition, the method is independent of use of cement or bony ingrowth of the device. The device may completely or substantially completely surround an intra-articular component or other components of the organism.

A device made from the material described above is capable of being formed to suit any joint cavity of animals or human beings, therefore the device may for example be formed to fit into any one of the following joints: Hip joint, knee joint, ankle joints, shoulder joint, elbow joints, wrist, fingers, spinal column joints, such as for substituting intervertebral discs, and the jaw joint.

The medical device may constitute the surface of a prosthetic device. It may be the entire surface or part of the surface of a prosthetic device. Also the device may constitute a complete or part of a hip endo-prosthesis, or it may be a breast prosthesis, a stent, a catheter, a heart valve or cartilage substitution.

Generally, the invention comprises the metallic and/or polymeric material as described above from which different medical devices may be manufactured, also the method of producing the device and medical devices is enclosed within the invention. Enclosed are methods of producing a device and medical devices as described above, as well as any combination of the features described for the device and the medical devices.

In another aspect the invention relates to a method for producing a polymeric and/or metallic device, the method comprising obtaining a number of at least one, two or three layers/fabrics of a material described herein, and positioning these layers/fabrics optionally further comprising one or more core, inlay and/or film in a sandwich composition, forming the sandwich composition of layers/fabrics by heating the composition followed by pressing it into a mould, where the heating and pressing processes optionally are conducted in vacuum, and providing the device in a desired shape.

In the method for producing a device wherein the device is as described above, at least three metal and/or polymer layers/fabrics may be utilised, these metal and/or polymer layers may further comprise a core with at least one layer of fabric on each side, where the core differs in constitution from the fabrics, preferred is the method for producing a device where the fabrics at the different sides of the core have equal constitutions.

The method for producing a device comprises two or more layers of fabrics, where the two or more layers of fabrics have a film of a metal and/or polymer layer in between each fabric.

In the method for producing a device the core and the film have similar composition except for the thickness of the metal and/or polymer layer. The thickness of the metal and/or polymer layers is as described above, in a preferred embodiment the film is between 0.01 and 2 mm thick, and the core is between 0.1 and 10 mm thick.

In an embodiment the method for producing a device comprises fabric, film and core where the structure of the fabric are composed of long polymer and/or metal fibre, and the core and film are composed of short chain polymers and/or metals. The polymer fibres can be selected among polyethylene (PE), polypropylene (PP) and polyvinylpyrrolidone (PVP). Most preferable is polyethylene (PE). The long polymer fibres are ultra high molecule weight polyethylene (UHMWPE) fibre and the short chain polymers may be branched.

In an embodiment the method for producing a device comprises fabric which is manufactured, e.g., woven, into a shape or form suitable for the shape of the device. The fabric consist of UHMWPE fibres in which the intersects are positioned as formerly described, preferably in angles of about 90 degree.

In an embodiment the method for producing a device comprises fabric which has high tensile strength and high wear resistance, and a core which absorbs shocks, pushes and strokes.

In an embodiment the method for producing a device comprises surface coating of the annealed device and further the device is sterilised by ionising radiation or by heating.

In another embodiment the method for producing a device comprises annealing the device before it is subjected to surface coating. In an embodiment the method for producing a device comprises surface coating of the device, as formerly described.

In a preferred embodiment the method for producing a device comprises production of the device where the shape and size of the device can be any possible to produce by pressing into to a mould, the mould forming a device which can be flat or round or in between and where the three-dimensional shape can be any possible forming by pressing into a mould.

The device can be utilised to produce a prosthetic device comprising metal and/or polymer layers, the order of the metal and/or polymer layers, and the method of production of the device as described above.

Preferred is a method of producing a prosthetic device of three metal and/or polymer layers, which constitute a core with at least one layer of fabric on each side. Another preferred constitution is a core which at each side has two layers of fabric with a film in between. A further preferred constitution is a film between two layers of fabric.

A further preferred device is a single fabric of metal. This fabric may be produced by metal fibre in a 2D (e.g. woven etc) or 3D network. Optionally the fabric of metal may further include a polymeric material according to the invention.

In a preferable embodiment of the method the prosthetic device are produced from- polymer layers optionally comprising one or more metal components composed of a polymer selected among polyethylene (PE), polypropylene (PP) and polyvinylpyrrolidone (PVP). Most preferable is a prosthetic device wherein the polymer layers are composed of polyethylene (PE).

In a further preferable embodiment of the method the prosthetic device are composed of fabrics of long metal and/or polymer fibre, preferable polymer fibre are ultra high molecule weight polyethylene (UHMWPE) fibre or other polyethylene fibre as previously described, whereas a core and film may be composed of short chain polymers, the short chain polymers may be branched. The fabric is of medical grade and can be woven into a shape suitable for the shape of the device. The shaping and physical characteristics is determined by the arrangement of the metal and/or polymeric e.g. UHMWPE fibres, the fibres can have intersects in angles as described formerly.

In a preferred embodiment the prosthetic device has a high tensile strength and a high wear resistance due to the properties of the fabrics, whereas the core absorbs shocks, pushes and strokes.

The metallic and polymeric constitution of the prosthetic device is obtained in accordance with the details given above where the metallic and/or polymer layers are heated, subjected to vacuum and pressed into shape in a mould, and further treated as described above.

Example

An implant is prepared with a shape as indicated in the figures i.e. cup-shaped. The implant is fabricated from 316L steel fibres fabric e.g. woven in a "Kόpertressenge- webe" (i.e. a Twill Dutch Weave) 20x250 mesh style with fibre diametres d=0.25 mm (warp yarn) and 0.20 mm (weft yarn).

The fabric is pressed into a mould to form the shape of the implant. This is performed at room temperature with sufficient pressure to deform the top fibres (i.e. the fibres in the circular surface of the implant) so that the implant is smoothed on the surface.

The surplus of material at the edges are cut off and the implant edges are partly melted (sintered) and rounded or a collar is added. The implant is now about 0.75 mm on the apex (top) and about 1.0 mm at the end of the skirts.

The implant is heat treated to remove inner tension and subsequently ethyleneoxide sterilised.

Claims

1. A medical device comprising

• at least one fabric of one or more metal fibre and/or • at least one wire of one or more metal fibre and/or

• at least one 3D network of one or more metal fibre and/or

• at least one aperture which is at least 1.5 cm in diameter.

2. The device according to claim 1 , further comprising • at least one fabric of one or more polymer fibre and/or

• at least one wire of one or more polymer fibre and/or

• at least one 3D network of one or more polymer fibre and/or

• at least one core, inlay and/or polymeric film and/or

• polymeric material intervened into said at least one fabric, wire and/or 3D network of one or more metal fibre.

3. The device according to any of the preceding claims further comprising one or more metal components which are selected from the group of powder, granulate, chopped fibres, long fibres, 2D structural components like plates, 3D structural components like shaped plates or hemicircles with holes.

4. The device according to any of the preceding claims, wherein said metal is selected from the group of pure metal and/or a metal alloy such as titanium, tantalum, gold, silver, chromium-cobaltum, zirconia, cobalt-chromium- molobdenum alloy and Stainless Steel alloys and/or a ceramic of one or more of these metals and alloys

5. The device according to any of the preceding claims, wherein said fabric is made by weaving, knitting and/or crocheting.

6. The device according to claim 5, wherein said fabric is made by a weaving technique selected from the group of cord woven, linen woven, mat woven, Celtic woven, twill woven, plain, rib, twill, panorama, atlas weave, basket weave, double weave, even weave, pile weave, pique weave, plain weave, satin/sateen weave or a combination hereof.

7. The device according to claim 5 or 6, wherein the number of orientations of fibre within the fabric is selected from 2, 3, 4, 5, 6, 7, 8, 9.

8. The device according to any of claim 5 to 7, wherein the fibre has an average thickness of 0.05 to 0.8 mm.

9. The device according to any of claim 5 to 8, wherein the fibre of the fabric is of similar average thickness.

10. The device according to any of claim 5 to 8, wherein the woven fabric comprises at least one orientation of warp yarn and at least one orientation of weft yarn, each of the weft yarn being passed over and under the at least one warp yarn and/or the others weft yam in a technique selected from 1 :1 , 1 :2, 1 :3, 1 :4, 1 :5, 2:2, 2:3, 2:4, 2:5, 3:3, 3:4, 3:5, 4:4, 5:5 the opposite in respect of overunder the yarn.

11. The device according to claim 10, wherein the warp yarn is at least 5% thicker than the weft yarn.

12. The device according to any of the preceding claims, wherein the aperture is a through-going aperture.

13. The device according to any of the preceding claims, wherein the aperture is not for ligaments.

14. The device according to any of the preceding claims, wherein the aperture is located in the area of the device which is subjected to load when the implant is positioned in a joint of an individual.

15. The device according to any of the preceding claims, wherein said implant is custom-made according to the dimension of the bone of the individual into which the implant is to be located.

16. The device according to claim 15, wherein said implant is custom-made by obtaining information of the bone size by photograph or by scanning.

17. The device according to any of the preceding claims, wherein said device has an upper surface, a lower surface and at least one edge and wherein at least said one edge is sealed by a collar.

18. The device according to any of the preceding claims, wherein said collar is of at least one polymeric component, optionally further comprising one or more metal components, or said collar is of a metal or metal alloy.

19. The device according to any of the preceding claims, wherein said device further comprises at least one marker.

20. The device according to any of the preceding claims, wherein said at least one marker is at least a thread and/or sphere of metal.

21. The device according to any of the preceding claims, wherein said at least one marker is supported by and/or incorporated into said collar.

22. The device according to any of the preceding claims, wherein said at least one marker is in the form of at least two units, and said two units is placed non-homogeneous within said device.

23. The device according to any of the preceding claims, wherein said device has a first and/or second side and wherein at least one of said first and second side further includes at least one cavity.

24. The device according to any of the preceding claims, wherein said device has at least one through-going perforation or aperture which is not for ligaments.

25. The device according to any of the preceding claims, wherein said at least one perforation or aperture is located in at least one area where said device is subjected to wear.

26. The device according to any of the preceding claims, wherein said medical device comprises at least a first unit with at least a convex surface and a second unit with at least a concave surface, where said convex and concave surface is congruent with each other and said first unit fit partially or entirely into said second unit.

27. The device according to any of the preceding claims, wherein said first and second unit have substantially similar shape and/or size.

28. The device according to any of the preceding claims, wherein said concave surface is at least 0.01 mm smaller than said convex surface.

29. The device according to any of the preceding claims, wherein said units are movable compared to each other, and said units continue to be in contact during a movement and/or return to be in contact when a movement is finished.

30. The device according to any of the preceding claims, wherein said first unit and/or said second unit is attached to an implant and/or a bone.

31. The device according to any of the preceding claims, wherein said first unit and/or said second unit can function without being attached to an implant and/or a bone.

32. The device according to any of the preceding claims, wherein said device is cup-shaped or approximately cup-shaped.

33. The device according to any of the preceding claims, wherein the device is a cup-shaped device with a rounded top and a skirt and wherein the thickness of said skirt is at least 5% larger than the thickness of a middle area of said rounded top.

34. The device according to any of the preceding claims, wherein said device is an acetabular cup, a spacer to be located between an acetabular cup and a head of a hip stem, or said device is an implant for interpositional arthroplasty

35. The device according to any of the preceding claims, wherein said device is part of a hip joint prosthesis, and where said device comprises a spacer e.g. a cup shaped spacer which is positioned between the natural femoral stem or a metal femoral stem and a natural acetabular cup or a prosthetic acetabular cup.