Implant to be implanted in bone tissue or in bone tissue supplemented with bone substitute material

• US 6,921,264 B2
• Filed: 09/12/2003
• Issued: 07/26/2005
• Est. Priority Date: 08/23/2002
• Status: Active Grant

• Current Assignee: Woodwelding AG
• Original Assignee: Woodwelding AG
• Inventors: Torriani, Laurent, Aeschlimann, Marcel, Mayer, Jorg
• Primary Examiner(s): O'Connor, Cary E.
• Assistant Examiner(s): STOKES, CANDICE CAPRI
• Application Number:
  US10/661,692
• Publication Number:
  US 20040053196A1
• Time in Patent Office: 683 Days
• Field of Search: 433/172, 433/173, 433/174, 433/175, 433/176
• US Class Current: 433/173
• CPC Class Codes: A61B 17/68 Internal fixation devices , including fasteners and spinal fixators, even if a part thereof projects from the skin bone staples A61B17/0642
• CPC Class Codes: A61B 17/70 Spinal positioners or stabilisers ; Bone stabilisers comprising fluid filler in an implant
• CPC Class Codes: A61B 2017/00955 thermoplastic
• CPC Class Codes: A61C 8/0012 characterised by the material or composition, e.g. ceramics, surface layer, metal alloy use of specific materials A61K6/00
• CPC Class Codes: A61C 8/0016 polymeric material
• CPC Class Codes: A61C 8/0018 characterised by the shape
• CPC Class Codes: A61C 8/0019 Blade implants
• CPC Class Codes: A61F 2/0077 Special surfaces of prostheses, e.g. for improving ingrowth A61F2/30767 takes precedence
• CPC Class Codes: A61F 2/30767 Special external or bone-contacting surface, e.g. coating for improving bone ingrowth
• CPC Class Codes: A61F 2/447 substantially parallelepipedal, e.g. having a rectangular or trapezoidal cross-section
• CPC Class Codes: A61F 2/4611 of spinal prostheses
• CPC Class Codes: A61F 2002/30032 differing in absorbability or resorbability, i.e. in absorption or resorption time
• CPC Class Codes: A61F 2002/30062 (bio)absorbable, biodegradable, bioerodable, (bio)resorbable, resorptive
• CPC Class Codes: A61F 2002/30064 Coating or prosthesis-covering structure made of biodegradable material
• CPC Class Codes: A61F 2002/30065 thermoplastic, i.e. softening or fusing when heated, and hardening and becoming rigid again when cooled
• CPC Class Codes: A61F 2002/30067 Coating or prosthesis-covering structure made of thermoplastic material
• CPC Class Codes: A61F 2002/30088 Phase change materials [PCM], e.g. for storing latent heat
• CPC Class Codes: A61F 2002/30593 hollow
• CPC Class Codes: A61F 2002/30784 Plurality of holes
• CPC Class Codes: A61F 2002/30878 with non-sharp protrusions, for instance contacting the bone for anchoring, e.g. keels, pegs, pins, posts, shanks, stems, struts
• CPC Class Codes: A61F 2002/30884 : Fins or wings, e.g. longitudinal wings for preventing rotation within the bone cavity
• CPC Class Codes: A61F 2002/30892 : parallel
• CPC Class Codes: A61F 2002/30899 : Protrusions pierced with apertures
• CPC Class Codes: A61F 2002/4627 : with linear motion along or rotating motion about the instrument axis or the implantation direction, e.g. telescopic, along a guiding rod, screwing inside the instrument
• CPC Class Codes: A61F 2002/4683 : by applying ultrasonic vibrations
• CPC Class Codes: A61F 2210/0004 : bioabsorbable
• CPC Class Codes: A61F 2210/0071 : thermoplastic
• CPC Class Codes: A61F 2210/008 : Phase change materials [PCM], e.g. for storing latent heat
• CPC Class Codes: A61F 2250/003 : differing in adsorbability or resorbability, i.e. in adsorption or resorption time
• CPC Class Codes: A61L 2430/02 : for reconstruction of bones; weight-bearing implants

Abstract

An implant (1) to be implanted in bone tissue, e.g. a dental implant or an implant for an orthopedic application, comprises surface regions (4) of a first type which have e.g. osseo-integrative, inflammation-inhibiting, infection-combating and/or growth-promoting properties, and surface regions (8) of a second type which consist of a material being liquefiable by mechanical oscillation. The implant is positioned in an opening of e.g. a jawbone and then mechanical oscillations, e.g. ultrasound is applied to it while it is pressed against the bone. The liquefiable material is such liquefied at least partly and is pressed into unevennesses and pores of the surrounding bone tissue where after resolidification it forms a positive-fit connection between the implant and the bone tissue. The surface regions of the two types are arranged and dimensioned such that, during implantation, the liquefied material does not flow or flows only to a clinically irrelevant degree over the surface regions of the first type such enabling the biologically integrative properties of these surface regions to start acting directly after implantation. The implant achieves with the help of the named positive fit a very good (primary) stability, i.e. it can be loaded immediately after implantation. By this, negative effects of non-loading are prevented and relative movements between implant and bone tissue are reduced to physiological measures and therefore have an osseo-integration promoting effect.

Claims

1. An implant for implantation in human or animal bone tissue or in bone tissue supplemented with bone substitute material, wherein at least a part of the implant surface is adapted to comes into contact with the bone tissue, wherein said part of the implant surface comprises surface regions (4) of a first type and surface regions (8) of a second type being different from the surface regions (4) of the first type, wherein the surface regions (8) of the second type comprise a material which is liquefiable by mechanical oscillation and with the aid of which on implantation by mechanical oscillation the implant is stabilized at least primarily in the bone tissue, wherein the surface regions (8) of the first type are equipped for a further clinical function being different from the function of primary stabilization and wherein the surface regions (4, 8) of the first type and of the second type are dimensioned and arranged in a manner such that the surface regions of the first type remain at least partly free from liquefied material on implantation by mechanical oscillation.

2. The implant according to claim 1, wherein the clinical function of the surface regions (4) of the first type, which function is different from primary stabilization, comprises osseointegration, permeation of particles or molecules out of the implant into bone tissue surrounding the implant or out of bone tissue surrounding the implant into the implant or electric or chemical stimulation.

3. The implant according to claim 1, wherein the liquefiable material is a material with thermoplastic properties or with thixotropic properties.

4. The implant according to claim 3, wherein the liquefiable material is a polymer based on lactic acid and/or glycolic acid, a polyhydroxy alkanoate, a polycaprolactone, a polysacharide, a polypeptide, a polydioxanone, a polyanhydride, a polyolefin, a polyacrylate, a polymetacrylate, a polycarbonate, a polyamide, a polyester, a polyurethane, a polysulphone, a polyarylketone, a polyimide, a polyphenyl sulphide, a liquid crystal polymer, a polyacetal, a halogenated polmer, in particular a halogenated polyolefin, a polyphenylene sulphide, a polysulphone, or a polyether or a copolymer or blended polymer of the said polymers or a composite material containing one of said polymers, or a polymeric, ceramic or hydraulic cement.

5. The implant according to claim 1, wherein the surface regions (4) of the first type comprise structures suitable for being ingrown or grown through by vital bone tissue.

6. The implant according to claim 5, wherein the surface regions (4) of the first type further have inflammation-inhibiting, infection-combating and/or growth-promoting properties.

7. The implant according to claim 1, wherein the surface regions (4, 8) of the first and of the second type are arranged beside each other and in parallel to an implantation direction (A).

8. The implant according to claim 1, comprising a central implant part (1) constituting the surface regions (4) of the first type and a peripheral implant part (2) being arranged on the outside of the central implant part, consisting at least partly of the liquefiable material and constituting the surface regions (8) of the second type.

9. The implant according to claim 8, wherein the surface regions (8) of the second type protrude at least locally over the surface regions (4) of the first type.

10. The implant according claim 1, comprising a central implant part (1) constituting the surface regions (4) of the first type and comprising an inner space (2′

) in which the liquefiable material is arranged or arrangeable, wherein the inner space (2′

) is connected to the outside of the central implant part (1) by openings (20) which are dimensioned for pressing the liquefiable material when liquid through and which are arranged in an area in which the surface regions (8) of the second type are to be produced.

11. The implant according to claim 7, wherein the implant has a load bearing function and the central implant part (1) constitutes the load bearing element of the implant.

12. The implant according to claim 11, wherein the central implant part (1) consists at least partly of a metal, a metal alloy, a ceramic material, a polymer or a composite material.

13. The implant according to claim 11, wherein the central implant part (1) comprises selfcutting or grooving elements.

14. The implant according to claim 11, wherein the central implant part (1) comprises a load bearing part (1.1) and a body part (1.2) having a variable shape.

15. The implant according to claim 11, wherein the central implant part (1) comprises a load bearing support (1.3) and a body (1.4).

16. The implant according to claim 15, wherein body (1.4) comprises a bone substitute material, bone chips or a gel.

17. The implant according to claim 8, wherein the peripheral implant part (2) is equipped for being a load bearing implant part.

18. The implant according to claim 17, wherein the central implant part (1) is a container having permeable walls or consists of a bone substitute material, of bone chips or of a gel.

19. The implant according to claim 1, being a dental implant and comprising at least one fixing location (3) or at least one crown part.

20. The implant according to claim 1, being equipped for an orthopedic application.

21. The implant according to claim 19, being pin-shaped, plate-shaped, disk-shaped or blade-shaped or having a shape being adapted or adaptable to the shape of a predetermined cavity in a bone.

22. The implant according to claim 20, being equipped for connecting two bone parts or for fixing a support plate or for serving as a shaft of a prosthesis for a hip joint, finger joint, knee joint, or shoulder joint.

23. The implant according to claim 1, having the shape of a spinal disk and comprising on its lower and upper side at least one ridge (40), wherein the surface regions (8) of the second type are arranged in the area of the ridges (40).

24. The implant according to claim 20, being pin-shaped, plate-shaped, disk-shaped or blade-shaped or having a shape being adapted or adaptable to the shape of a predetermined cavity in a bone.

25. A method for implanting an implant in bone tissue or in bone tissue supplemented with bone substitute material, the method comprising the steps of:

providing an implant having an implant surface of which at least a contact part is adapted to come into contact with the bone tissue, wherein said contact part of the implant surface comprises surface regions of a first type and surface regions of a second type that are different from the surface regions of the first type, wherein the surface regions of the second type comprise a material that is liquefiable by mechanical oscillation, and wherein the surface regions of the first type are equipped for a further clinical function that is different from the function of primary stabilization;

positioning the implant on or in the bone tissue;

applying mechanical oscillation to the implant and at the same time pressing the implant against the bone tissue, thereby liquefying at least part of the liquefiable material and pressing the liquefied material into unevenesses and pores of the bone tissue;

re-solidifying the liquefied material to form a connection with the bone tissue for primarily stabilizing the implant in the bone tissue;

wherein the surface regions of the first and second type are dimensioned and arranged in a manner such that the surface regions of the first type remain at least partly free from liquefied material when mechanical oscillation is applied to the implant and the implant is pressed against the bone tissue; and

wherein the surface regions of the second type are equipped and arranged for the further clinical function taking effect on the bone tissue immediately after the step of re-solidifying.

26. The method according to claim 25, wherein the implant is loaded immediately after the step of re-solidifying.

27. The method according to claim 25, wherein before the step of positioning, an opening suitable for positioning the implant is produced in the bone tissue.

28. The method according to claim 27, wherein the bone comprises a cortical part and a cancellous part underneath the cortical part, wherein the opening is produced in the cortical part and wherein the step of applying and pressing comprises advancing the implant into the cancellous part.

29. The method according to claim 25, wherein the implant is positioned on the bone tissue and the step of pressing comprises pressing the implant in a self cutting manner into the bone tissue.

30. The method according to claim 25, wherein before the step of positioning, unevenesses of a suitable geometry are produced in the bone tissue, into which unevenesses the liquefied material is to be pressed.

31. The method according to claim 25, wherein the step of applying and pressing comprises positioning a sonotrode of an ultrasound device on a proximal face of the implant.

32. The method according to claim 25, wherein the implant has the form of a cavity in the bone tissue and is implanted in this cavity.

33. The method according to claim 32, wherein the cavity is created by extracting a natural tooth root from a jaw bone.

34. The method according to claim 25, wherein the step of providing comprises combining two implant parts of two different materials to form the implant.

35. The method according to claim 25, wherein after the step of re-solidifying a further implant part is fixed on a proximal end of the implant.

36. The method according to claim 25, wherein the implant is designed for connecting two vertebrae and the step of applying and pressing comprises pushing the implant between the two vertebrae.

37. A method for implanting an implant in bone tissue or in bone tissue supplemented with bone substitute material, the method comprising the steps of:

providing an implant having an implant surface of which at least a contact part is adapted to come into contact with the bone tissue, wherein said contact part of the implant surface comprises surface regions of a first type and surface regions of a second type that are different from the surface regions of the first type, wherein the surface regions of the second type comprise openings to an inside cavity of the implant, the inside cavity containing a material which is liquefiable by mechanical oscillation, and wherein the surface regions of the first type are equipped for a further clinical function that is different from the function of primary stabilization;

positioning the implant on or in the bone tissue;

applying mechanical oscillation to the implant and at the same time applying a force to the liquefiable material in the cavity, thereby liquefying at least part of the liquefiable material and pressing the liquefied material through the openings in the surface regions of the second type and into unevenesses and pores of the bone tissue;

re-solidifying the liquefied material to form a connection with the bone tissue for primarily stabilizing the implant in the bone tissue,

wherein the surface regions of the first and second type are dimensioned and arranged in a manner such that the surface regions of the first type remain at least partly free from liquefied material when the mechanical oscillation is applied to the implant and the liquefied material is pressed through the openings; and

wherein the surface regions of the second type are equipped and arranged for the further clinical function taking effect on the bone tissue immediately after the step of re-solidifying.

38. The method according to claim 37 wherein the implant is loaded immediately after the step of re-solidifying.

39. The method according to claim 37, wherein before the step of positioning, an opening suitable for positioning the implant is produced in the bone tissue.

40. The method according to claim 39, wherein the bone comprises a cortical part and a cancellous part underneath the cortical part, wherein the opening is produced in the cortical part and wherein the step of applying and pressing comprises advancing the implant into the cancellous part.

41. The method according to claim 37, wherein the implant is positioned on the bone tissue and the step of pressing comprises pressing the implant in a self cutting manner into the bone tissue.

42. The method according to claim 37, wherein before the step of positioning, unevenesses of a suitable geometry are produced in the bone tissue, into which unevenesses the liquefied material is to be pressed.

43. The method according to claim 37, wherein the step of applying and pressing comprises positioning a sonotrode of an ultrasound device on a proximal face of the implant.

44. The method according to claim 37, wherein the implant has the form of a cavity in the bone tissue and is implanted in this cavity.

45. The method according to claim 44, wherein the cavity is created by extracting a natural tooth root from a jawbone.

46. The method according to claim 37, wherein the step of providing comprises combining two implant parts of two different materials to form the implant.

47. The method according to claim 37, wherein after the step of re-solidifying a further implant part is fixed on a proximal end of the implant.

48. The method according to claim 37, wherein the implant is designed for connecting two vertebrae and the step of applying and pressing comprises pushing the implant between the two vertebrae.