Prophylactic implant against fracture of osteoporosis-affected bone segments

• US 6,319,255 B1
• Filed: 06/18/1999
• Issued: 11/20/2001
• Est. Priority Date: 12/18/1996
• Status: Expired due to Fees

• Current Assignee: Eska Implants GmbH & Co. KG.
• Original Assignee: Eska Implants GmbH & Co. KG.
• Inventors: Grundei, Hans, Thomas, Wolfram
• Primary Examiner(s): REIP, DAVID OWEN
• Application Number:
  US09/336,023
• Time in Patent Office: 886 Days
• Field of Search: 606/62, 606/60, 606/61, 606/65, 606/66, 606/67, 606/68, 606/72, 606/76, 606/77, 606/63, 623/16.11, 623/17.11, 623/17.16, 623/20.36
• US Class Current: 606/76
• CPC Class Codes: A61B 17/70 Spinal positioners or stabilisers ; Bone stabilisers comprising fluid filler in an implant
• CPC Class Codes: A61B 17/72 Intramedullary pins, nails or other devices A61B17/744 takes precedence
• CPC Class Codes: A61B 17/7233 with special means of locking the nail to the bone
• CPC Class Codes: A61B 17/7258 with laterally expanding parts, e.g. for gripping the bone
• CPC Class Codes: A61B 17/742 having one or more longitudinal elements oriented along or parallel to the axis of the neck
• CPC Class Codes: A61F 2/2846 Support means for bone substitute or for bone graft implants, e.g. membranes or plates for covering bone defects nets or sleeves applied to surface of endoprostheses A61F2/30907; bone plates A61B17/80; bone regeneration in dental surgery A61C8/0006
• CPC Class Codes: A61F 2/30744 End caps, e.g. for closing an endoprosthetic cavity
• CPC Class Codes: A61F 2/3601 for replacing only the epiphyseal or metaphyseal parts of the femur, e.g. endoprosthetic femoral heads or necks directly fixed to the natural femur by internal fixation devices non-prosthetic internal fixation devices for the femoral head or neck A61B17/74
• CPC Class Codes: A61F 2/44 for the spine, e.g. vertebrae, spinal discs
• CPC Class Codes: A61F 2002/2821 Bone stimulation by electromagnetic fields or electric current for enhancing ossification
• CPC Class Codes: A61F 2002/2832 Femoral neck
• CPC Class Codes: A61F 2002/2835 Bone graft implants for filling a bony defect or an endoprosthesis cavity, e.g. by synthetic material or biological material
• CPC Class Codes: A61F 2002/30064 Coating or prosthesis-covering structure made of biodegradable material
• CPC Class Codes: A61F 2002/30235 tubular, e.g. sleeves
• CPC Class Codes: A61F 2002/30579 with mechanically expandable devices, e.g. fixation devices
• CPC Class Codes: A61F 2002/30593 hollow
• CPC Class Codes: A61F 2002/30668 Means for transferring electromagnetic energy to implants
• CPC Class Codes: A61F 2002/30785 parallel
• CPC Class Codes: A61F 2002/30787 inclined obliquely with respect to each other
• CPC Class Codes: A61F 2002/30912 made of expanded metal, e.g. diamond mesh or metal nets having lozenge-shaped apertures
• CPC Class Codes: A61F 2002/3092 : having an open-celled or open-pored structure
• CPC Class Codes: A61F 2002/3625 : Necks
• CPC Class Codes: A61F 2230/0069 : cylindrical
• CPC Class Codes: A61F 2250/0001 : Means for transferring electromagnetic energy to implants
• CPC Class Codes: A61F 2310/00011 : Metals or alloys
• CPC Class Codes: A61F 2310/00293 : containing a phosphorus-containing compound, e.g. apatite
• CPC Class Codes: A61F 2310/00796 : Coating or prosthesis-covering structure made of a phosphorus-containing compound, e.g. hydroxy(l)apatite
• CPC Class Codes: Y10S 606/908 : Bioabsorbable material

Abstract

A prophylactic implant is provided for protecting osteoporosis-affected bone segments against fractures, in particular the neck of the femur, the vertebral column and the wrist. According to a proposed solution, the implant comprises a thin-walled hollow reinforcing body (1) having such a large number of passages (2) in its outer wall (3) that the ratio of the total area of the passages (2) to the total surface area is at least 1:2.

Claims

1. A method for prophylaxis against fractures of osteoporosis-affected bone segments, comprising the steps of creating a bore in the osteoporosis-affected bone segment, and inserting into the created bore a thin-walled hollow reinforcing body having such a large number of passages in its outer wall that the ratio of the total area of the passages to the total surface area is at least 1:

2, such that bone material of the bone segment can grow through the passages into an interior of the reinforcing body.

2. The method of claim 1, wherein the reinforcing body comprises a biocompatible metal, and wherein an open-mesh, three-dimensional spatial network structure is provided at least in sections on its surface.

3. The method of claim 1, wherein the reinforcing body comprises a biocompatible plastic, and wherein the reinforcing body is deformable by a built-in mechanism for application of a pulling force.

4. The method of claim 1, wherein the bore is made in a femur bone neck, and wherein the reinforcing body comprises a substantially cylindrical sleeve, which is distally closed with a convex head member and is proximally closable with a closing piece.

5. The method of claim 4, wherein the convex head member is provided at least partially with a spatial network structure.

6. The method of claim 4, wherein the proximal closing piece is provided at least partially with a spatial network structure.

7. The method of claim 4, wherein a threaded shaft runs in the interior of the sleeve between the head member and the closing piece and is connected to these, the threaded shaft being capable of generating a pulling force upon its rotation.

8. The method of claim 4, wherein a pulling cord is tensioned in the interior of the sleeve between the head member and the closing piece, the pulling cord being further tensionable from outside the sleeve in order to be able to generate a pulling force for deformation of the sleeve.

9. The method of claim 1, wherein the outer wall is coated with an agent resorbable by the patient'"'"'s body.

10. The method of claim 9, wherein the agent is hydroxylapatite.

11. The method of claim 9, wherein the agent comprises an alpha-tricalcium phosphate ceramic.

12. The method according to claim 1, wherein the bore is made in bone selected from the group consisting of a femur bone neck, a vertebral column and a wrist joint bone.

13. The method of claim 1, wherein an electrical coil is arranged on a magnetic core centrally arranged in the reinforcing body, the electrical coil being activatable from outside the body.

14. The method of claim 13, wherein the magnetic core is constructed as a threaded shaft.

15. The method of claim 13, wherein a head member of the reinforcing body has an extension protruding into the interior of the reinforcing body and has a recess for securing the centered position of the magnetic core.

16. A method for prophylaxis against fractures of osteoporosis-affected bone segments, comprising the steps of creating a bore in the osteoporosis-affected bone segment, and inserting into the created bore a solid implant core forming a reinforcing core for the bone segment, the surface of the solid implant core being provided at least partially with an open-mesh, three-dimensional spatial network structure.

17. The method according to claim 16, wherein the bore is made in bone selected from the group consisting of a femur bone neck, a vertebral column and a wrist joint bone.

18. A method for prophylaxis against fractures of osteoporosis-affected bone segments, comprising the steps of creating a bore in the osteoporosis-affected bone segment, and inserting into the created bore a hollow tube whose outer wall comprises an open-mesh, three-dimensional spatial network structure.

19. The method according to claim 18, wherein the bore is made in bone selected from the group consisting of a femur bone neck, a vertebral column and a wrist joint bone.

20. The method of claim 18, wherein the hollow tube forms a sleeve which is closable with a closing piece on its proximal end, wherein the closing piece also comprises an open-mesh, three-dimensional spatial network structure.