HK1082396B - Supporting element for attachment to bone - Google Patents

Description

Support element for attachment to bone

Technical Field

The present invention relates to a support element for attachment to bone.

Background

Elements which are screwed onto or into bone, such as plates for bridging fractures, are known. These plates are usually made of a biocompatible material, such as titanium, and are fixed to the bone with fixation screws. It is not possible for the plate to be tightened firmly onto the bone without impairing the growth of the underlying bone. Tightening the plate firmly onto the bone will cut or at least restrict blood vessels in the bone below the plate. Osteolysis may occur. This means that the mechanical properties of the plate/bone combination are not optimal, since the fixation part of the plate is relatively loose. Furthermore, the use of these elements will be limited. For example, controlled vibrations that may cause and promote bone growth have to be limited or even avoided, and mechanical loads, such as those used for micro-motion control, have to be minimized.

Disclosure of Invention

The present invention is directed to a support element that provides better attachment to bone and better mechanical properties. Previous inventions have attempted to avoid the aforementioned problems using a dimpled pattern on the underside.

It is an object of the present invention to provide a support element for attachment to bone that can be attached relatively firmly without cutting or constricting blood vessels, nerves or the like.

It is a further object of the present invention to provide a support element which can be attached to bone and which in use can induce and/or promote bone growth.

It is a further object of the invention to provide a support element that can be mechanically loaded almost directly after the element is attached to bone.

These and further objects of the invention are achieved by a support element having the following features.

In particular, a support element for attachment to bone, comprising means for positioning attachment means, and a surface for positioning against the bone, wherein the surface is provided, at least in use, with a spongy biocompatible material enclosed between the bone and the surface; characterised in that the spongy biocompatible material is provided in the form of granules having internal pores, said granules having at least micro-spaces therebetween, and in use bone ingrowth into and/or out of said micro-spaces and ingrowth into said granules.

In the support element, the connecting means may be a screw or a tape.

In the support element, the spongy biocompatible material may include titanium made by reacting titanium tetrachloride.

In the support element, the surface may be provided with at least one recess, the material being provided in the recess.

In the support element, the material may adhere to the surface.

In the support element, the support element may be or have at least one partially plate-shaped element comprising the surface provided with the spongy biocompatible material.

In the support element, the surface may be curved in at least one direction.

In the support element, a bone growth promoter may be provided on and/or in the spongy biocompatible material and/or on the surface.

In the support element, the surface may be formed by a strip of material, which strip is relatively flexible.

In the support element, the tape may be at least partially adhesive, so that the tape may be adhered to an element to be fixed to bone and/or to itself.

In the support element, the strip of material may be sufficiently flexible to be folded or bent into any shape that can be used as a filling.

In the support element, the strip of material may be arranged on a surface of the support element.

In the support element, the bone growth promoter may be a bone growth inducing or promoting chemical agent.

By providing a spongy biocompatible material on one surface of the elements, which provides space in which bone may grow, the elements can be attached relatively firmly, the elements resting on the bone to which they are attached. In addition, the sponge-like biocompatible material may prevent cutting or restricting the blood vessels underneath the element. Thereby, osteolysis may be at least substantially prevented.

Since the element according to the invention can be attached relatively firmly to the bone, it can be mechanically loaded, even directly after fixation. For example, the element may be vibrated to facilitate and promote bone growth, or a known mechanical device may be coupled to the element to facilitate or control micro-motion of the element.

Preferably, the spongy biocompatible material is provided at least in part as particles having internal pores. These particles are preferably made using a material produced by the reaction of titanium tetrachloride, which is crushed to maintain internal microporosity. The particles can easily be placed onto the surface of the element and provide a desired pressure distribution, while they simultaneously provide space into and/or out of which bone can grow. If desired, the granules may be mixed with, for example, bone meal or other bone production inducing and/or promoting substances such as chemicals, blood, etc.

At least one surface of the element, which has been or will be provided with said spongy biocompatible material, may have at least one recess, for example by providing an upstanding peripheral wall. When the member is threadably secured, the upstanding wall at least substantially engages the bone such that at least a portion of the surface is maintained at a distance from the bone with the spongy biocompatible material disposed therebetween. This results in an easy enclosure of the material. The surface may be curved in at least one direction for a better fit to bone, for example a so-called long bone. It will be apparent, however, that any shape, size or form is suitable for use.

The invention also relates to the tape itself, which is provided with a sponge-like biocompatible material, for example a titanium-based material, on at least one side. The tape is particularly suitable when the titanium-based material is made by reacting titanium tetrachloride, which tape is relatively flexible. Such a tape, which is likewise inventive per se, is particularly suitable for use in combination with, for example, a screw-fastening element according to the invention. A strip of tape may be provided on the element and/or on the surface of the element before the element is positioned. The number of strips and possibly the kind of choice may then be chosen depending on, for example, the patient and the type of component. The amount and type of material on the tape surface and, for example, the distribution can then be varied. The tape may also be used alone, separate from the element, for example for wrapping around bone; or can be wound up to be used as a filler.

The invention also relates to an assembly of a support element, for example of the screw-on type, and granules of a biocompatible material in the form of a sponge having internal pores, in which means are provided for enclosing the granular material between the element and the bone. For this purpose, the granular material may be provided with or mixed with an adhesive substance, such as blood, a biocompatible adhesive, etc., or may be provided on said tape or similar substance. Alternatively, a mechanical device may be used, which is preferably (semi-) permeable with respect to bone growth agents, blood, etc.

In a preferred embodiment, the assembly according to the invention is characterized in that the tape according to the invention is arranged on at least one surface of the support element or at least connected thereto for providing at least a partial connection of said element to bone.

An advantage of such an assembly is that the tape can be used to at least temporarily attach an element to bone if the tape and/or the granules are provided with adhesive substance on both sides. In this way, the support element can be easily positioned and screwed, if necessary. The element (plate) may also be attached to the bone by wrapping the tape around the element and the bone. Obviously, the element (plate) itself can also be provided with adhesive means (substance).

In another aspect, the invention also relates to the preparation of a support element as described above, wherein a spongy biocompatible material having an internal pore structure is arranged on a surface to be placed against said bone, such that the particles are enclosed between said surface and said bone.

According to the invention, an element is easily attached to bone, for example, in particular on its relatively smooth, flat or curved outer surface, preventing cutting or restriction of blood vessels, nerves or the like within said bone. The granules also have the advantage of promoting bone growth, or at least preventing osteolysis.

Drawings

In order that the invention may be better understood, embodiments of the support element, assembly, tape, application, preparation and method according to the invention will be shown and described below with reference to the accompanying drawings.

Fig. 1 is a schematic perspective view of a support element according to the invention from the front side without particles.

Fig. 2 is a view from the rear side of the element according to fig. 1;

FIG. 3 is a view from the front side of the element of FIGS. 1 and 2 partially filled with particles;

FIGS. 4 and 4A are cross-sectional views of a member according to the present invention threaded onto bone;

fig. 5 is a view of an element according to the invention screwed onto a fractured bone in a first alternative embodiment;

FIG. 6 is a side view of a roll of tape according to the present invention;

fig. 7 is a partially cut-away front view of the strip of material of fig. 6;

fig. 8 is a perspective view of the strip of material according to fig. 6 and 7 partially twisted; and

figure 9 shows a support element according to the invention being placed on a bone by means of a tying device.

Detailed Description

In the present application, the same or corresponding portions have the same or corresponding reference numerals. These embodiments are shown by way of example only and should not be construed to limit the invention in any way. In the present description, the term "particles" is used to indicate relatively small granules of biocompatible material, such as metal, preferably in the form of a sponge having at least micropores, these particles being obtained by breaking up or grinding large granules, and they being preferably obtained by reacting titanium tetrachloride. These particles are preferably crushed in a manner that maintains their internal microporosity. Particles of different sizes and different materials may be used alone or in combination.

Fig. 1-3 show a support element in a first preferred embodiment, which may be referred to as a screw-on type plate 1. The plate 1 is made of a biocompatible material (such as, but not limited to, titanium alloy) or a biocompatible or biodegradable plastic. The plate 1 has a curved configuration such that it is substantially straight in the longitudinal direction L and it is curved in the transverse direction W, substantially forming a ring segment. The plate 1 is substantially smooth on its convex outer side 2 and is provided with two through holes 3 extending through the plate. On the opposite bottom side 4, a straight wall 5 extends around the outer edge of the plate and encloses a concave lower surface 6, which bottom side 4 in use faces the bone to which the plate 1 is screwed. The through-hole 3 is also surrounded by a wall 7 on the bottom side 4 of the plate 1. The plate 1 is thus formed with at least one recess or groove 8, which is constituted by the lower surface 6, the inner edge 9 of the wall 5 and the wall 7.

As can be seen from fig. 3, the recess or hollow 8 can be completely or partially filled with a biocompatible granular material, which is referred to below as the granules 10 described above. The granules 10 are positioned in said hollows or grooves 8 by using, for example, an adhesive substance 11, such as blood, a biocompatible adhesive, gelatin, etc., so that the granules 10 are at least temporarily adhered to each other and/or to the plate 1, in particular to said lower surface 6. It is clear that the granules 10 can also be arranged in different ways, for example by enclosing the granules in bags, nets or the like, so that the granules can be arranged on at least a part of at least one surface of the plate, in particular on the lower surface 6. In particular, in such an embodiment, the lower surface 6 may also be completely or substantially flat without the upstanding wall 5.

In fig. 4, in a sectional view along the line IV-IV in fig. 3, the element 1 is shown screwed to the bone 12 by means of screws 13 extending through said through holes 3 and screwed into the bone 12. The particles 12 are thus enclosed between the outer surface 14 of the bone 12 and the inner surface 6 of the element 1. Since the element 1 is tightened by the screw 13 and is supported on the surface 14 mainly by the particles 10, the screw 13 can be tightened relatively firmly to squeeze the particles 10 between the two surfaces 6, 14 without the risk of cutting nerves, blood vessels, etc. in the bone 12.

In fig. 4A, an alternative embodiment of the element is shown in the same sectional view as in fig. 4, wherein the particles are adhered to the element 1, in particular to said inner surface 6, by means of a layer 15 of adhesive material, such as a double-sided adhesive tape or a layer 15 of biocompatible glue. Obviously, this layer 15 can be made of any material having adhesive properties, including a gum-like material. In this embodiment, the element 1 is also screwed to the bone 12 by means of screws 13.

In fig. 5, an element 1 according to a further alternative embodiment of the invention is screwed to a bone 12 with a screw 13, enclosing a particle 10 between an inner surface 6 and an outer surface 14 of the bone 12. In this embodiment, the element 1 extends across a fracture 16 in the bone 12 and a connecting element 17, for example a button element, is provided on the outer surface 2. As an example, a connection device can be connected to the button element, so that it can be connected to an external wiring harness, a vibration device or the like in order to mechanically load the element 1, for example to cause or control a micro-movement of the element 1. Such devices are known in the art.

Fig. 6-8 show a strip of material 18 according to the invention provided with particulate material 10 on at least one outer surface 19 as described above. Such particulate material 10 may be disposed on, completely filling, the outer surface 19, as shown in fig. 8, wherein the particles 10 are of substantially similar size and are disposed densely on the surface. The particles 10 may also be arranged on the surface in a specific pattern, as shown in fig. 7, wherein two areas 20 of relatively dense particles are arranged along an outer edge 21 of the strip of material 18, and one area 22 of less dense particles is arranged along the middle of the outer surface 19. The zones 20, 22 may be separated by a zone 23 without any particles. Fig. 7 shows only one example of such a pattern. Any pattern of distribution of the particles is obviously possible. The tape may be formed by providing an adhesive on the outer surface 19 to which the particles adhere. The granules themselves may also be provided with a cohesive material, such as blood, gelatin, biocompatible glue, etc. In such an embodiment, the tape 18 may be adhered to any surface, for example bone or a surface of the element 1 according to the invention, by means of said adhesive substance.

The tape 18 according to fig. 6-8 can be used as a layer in combination with the layer 15 and the granules 10 shown in fig. 4A and enclosed between the element 1 according to the invention and the bone 12. However, the strip of material 18 may be folded, kneaded, twisted, etc. to be suitable for use as a bone filler or the like. In an alternative embodiment, the tape 18 may be wrapped around the outer surface 2 of the element 1 and the bone 12, wherein the tape 18 may be adhered to said element 1, said bone 12 and/or itself.

In fig. 9, another embodiment of an assembly according to the invention is shown, wherein an element 1 (such as shown in fig. 3) with granules 10 is attached to the outer surface 14 of a bone 12 by means of a fastening device 25, such as a biocompatible plastic tie, an elastic band or the like. The strip of material 18 may also serve as a fastening device 25.

By using an assembly according to the invention, for example an assembly consisting of a support element 1, a tape 18 and/or attachment means such as screws, said tape and/or ties or the like, a support element 1 according to the invention can be arranged on a surface 14 of a bone, such as a skeletal part of a human body such as a bone end, and can thus be fixed relatively firmly to said bone, preventing cutting of blood circulation, nerves or the like, and preventing osteolysis. Such a support element can be loaded with external forces almost immediately after attachment to the bone. The granule 10 will allow and possibly even promote bone growth into the granule in order to obtain a better connection. The particles 10 may be mixed with, for example, bone material, in particular bone material of a patient, which may lead to bone ingrowth into and out of the particle material, thereby further enhancing the connection of the element 1.

The invention is not limited in any way to the embodiments described and shown in the drawings. Many modifications and embodiments of the invention are possible within the scope of the invention as defined in the claims or the description.

For example, the strip of material 18 according to the invention may be provided, for example, with particulate material on both sides, which may be of similar material or of completely different material. The support element 1 according to the invention may have any shape, size or configuration, which may be adapted to a specific bone structure, such as a long bone, a short bone, a pelvis, a shoulder bone, etc. The strip of material 18 according to the invention is particularly suitable for use with the element 1 according to the invention, but may also be used separately. The particles may be at least partially replaced with other biocompatible materials that distribute the coupling force in a similar manner, such as a mat with a roughened surface, etc. Other attachment means may be used in place of the screw 13, such as a nut and bolt extending through the bone, nail, etc.

Claims (18)

1. A support element for attachment to bone, comprising means for seating an attachment means, and a surface for seating against the bone, wherein the surface is provided, at least in use, with a spongy biocompatible material enclosed between the bone and the surface; characterised in that the spongy biocompatible material is provided in the form of granules having internal pores, said granules having at least micro-spaces therebetween, and in use bone ingrowth into and/or out of said micro-spaces and ingrowth into said granules.

2. Support element according to claim 1, wherein the connection means are screws or tape.

3. The support element of claim 1, wherein the spongy biocompatible material comprises titanium made by reacting titanium tetrachloride.

4. A support element as claimed in any one of claims 1 to 3, characterized in that the surface is provided with at least one recess in which the material is arranged.

5. A support element as claimed in any one of claims 1 to 3, characterized in that said material adheres to said surface.

6. A support element as claimed in any one of claims 1 to 3, characterized in that the support element is or has at least one partially plate-shaped element comprising the surface provided with the sponge-like biocompatible material.

7. A support element as claimed in any one of claims 1 to 3, characterized in that the surface is curved in at least one direction.

8. A support element as claimed in any one of claims 1 to 3 wherein a bone growth promoter is provided on and/or in the spongy biocompatible material and/or on the surface.

9. A support element as claimed in any one of claims 1 to 3, characterized in that said surface is formed by a strip of material, said strip of material having a relative flexibility.

10. Support element according to claim 9, wherein the tape is at least partially adhesive, so that the tape can be adhered to an element to be fixed to bone and/or to itself.

11. A support element as claimed in claim 9, wherein the strip of material is sufficiently flexible to be folded or bent into any shape which can be used as a filler.

12. A support element as claimed in claim 1, wherein the support element is provided with a tape on a surface thereof.

13. The support element of claim 8, wherein the bone growth promoter is a bone growth inducing or promoting chemical.

14. Assembly of a support element according to any one of claims 1 to 3, one surface of which can be attached to bone, and granules of spongy biocompatible material having internal porosity, said assembly being provided with means for positioning said granules between said bone and said surface.

15. The assembly of claim 14, wherein the surface is threadably secured to the bone.

16. The assembly of claim 14, wherein the particles are made of titanium.

17. The assembly of claim 16, wherein the titanium is made by reacting titanium tetrachloride.

18. Preparation of a support element according to claim 1, wherein a biocompatible material having an internal pore structure is placed on a surface to be placed against the bone, so that the particles are enclosed between the surface and the bone.