Material as a starting material for the preparation of bone cement, process for its preparation and process for the preparation of bone cement

• US 5,574,075 A
• Filed: 06/08/1993
• Issued: 11/12/1996
• Est. Priority Date: 10/19/1990
• Status: Expired due to Fees

• Current Assignee: Klaus Draenert
• Original Assignee: Klaus Draenert
• Inventors: Draenert, Klaus
• Primary Examiner(s): Michl, Paul R.
• Assistant Examiner(s): MERRIAM, ANDREW EDWIN
• Application Number:
  US08/039,359
• Time in Patent Office: 1,253 Days
• Field of Search: 523/116, 523/117, 523/118, 604/56, 604/82, 606/92
• US Class Current: 523/116
• CPC Class Codes: A61B 17/8833 Osteosynthesis tools specially adapted for handling bone cement or fluid fillers; Means for supplying bone cement or fluid fillers to introducing tools, e.g. cartridge handling means
• CPC Class Codes: A61F 2/28 Bones joints A61F2/30
• CPC Class Codes: A61L 24/06 obtained by reactions only involving carbon-to-carbon unsaturated bonds A61L24/043, A61L24/046 take precedence
• CPC Class Codes: A61L 2430/02 for reconstruction of bones; weight-bearing implants
• CPC Class Codes: C08L 33/06 of esters containing only carbon, hydrogen and oxygen, which oxygen atoms are present only as part of the carboxyl radical

Abstract

The invention relates to a material in the form of a three-dimensional conglomerate of polymer particles which is used as a starting material for the preparation of bone cement. The conglomerate is a solid with a uniform pore system and is prepared by bonding the polymer particles to one another at their points of contact or connecting them at their surfaces. After addition of the monomer the material is prepared to a self-curing bone cement and mixed.

Claims

1. A bone cement polymer component as a starting material for preparing bone cement, wherein the polymer component comprises a three-dimensional conglomerate of polymer particles and wherein the polymer component is a solid and contains a pore system.

2. The bone cement polymer component according to claim 1, wherein the pore system is uniform.

3. The bone cement polymer component according to claim 1, wherein the polymer particles are selected from the group consisting of prepolymers of polyacrylates or polymethacrylates, a copolymer of an acrylate and a methacrylate and mixtures thereof.

4. The bone cement polymer component according to claim 1, wherein the conglomerate is packed or welded in evacuated state.

5. The bone cement polymer component according to claim 4, wherein the conglomerate is evacuated in a vessel.

6. The bone cement polymer component according to claim 1, wherein the conglomerate additionally contains filler particles in a form selected from the group consisting of spheres, granules and threads.

7. The bone cement polymer component according to claim 6, wherein the filler particles are radiographic contrast agents or bone-inducing particles.

8. The bone cement polymer component according to claim 6, wherein the filler particles are between 50 and 300 μ

m in size.

9. The bone cement polymer component according to claim 1, wherein the polymer particles are pressed into a conglomerate in tablet form.

10. The bone cement polymer component according to claim 1, wherein cavities in the form of a canal system are provided in the conglomerate.

11. The bone cement polymer component according to claim 1, wherein the polymer particles in the conglomerate are bonded to one another at their points of contact.

20. The bone cement polymer component according to claim 1, wherein the polymer component is prepared and mixed into a self-curing bone cement by adding a monomer.

22. The bone cement polymer component according to claim 4, wherein the conglomerate is welded under vacuum pressure.

23. The bone cement polymer component according to claim 4, wherein the conglomerate is welded under vacuum pressure within a packing material, said, packing material being made of an airtight PMMA film.

24. The bone cement polymer component according to claim 6, wherein the filler particles have a thread length between 0.5 and 5 mm.

25. The bone cement polymer component according to claim 6, wherein the filler particles have a thread length up to 3.5 mm.

26. The bone cement polymer component according to claim 1, wherein the polymer particles in the conglomerate are connected to one another at their surfaces.

12. A process for preparing a bone cement polymer component comprising:

providing powdered polymer particles; and

heating the powdered polymer particles at temperatures between 70° and

120°

C. such the polymer particles are bonded to one another at their points of contact and converted into a three-dimensional conglomerate of polymer particles wherein the conglomerate is a solid and contains a pore system.

13. A process for preparing a bone cement polymer component comprising:

providing powdered polymer particles; and

pressurizing the polymer particles such that the polymer particles are connected to one another at their surfaces and converted into a three-dimensional conglomerate of polymer particles wherein the conglomerate is a solid and contains a pore system.

18. The process according to claim 13, wherein a press mold is used for pressurization which is designed such that a canal system is provided in the formed conglomerate.

19. The process according to claim 18, wherein the press mold is cylindrical and comprises several means in its interior which serve as space retainers for the canal system.

30. The process according to claim 18, wherein the means which serve as spore retainers for the canal system includes pins.

14. A process for preparing a bone cement polymer component comprising:

providing powdered polymer particles; and

applying heat between 50° and

150°

C.;

applying simultaneously with the heat pressurization between 1 and 10 bar, such that the powdered polymer particles are solidified into a three-dimensional solid conglomerate having a pore system.

27. The process according to claim 14, wherein the heat is applied between 70°

and 100°

C.

28. The process according to claim 14, wherein the pressure is applied at between 3 to 5 bar.

29. The process according to claim 14, wherein the pressure is applied at approximately 5 bar.

15. A process for preparing a bone cement polymer component comprising:

providing powdered polymer particles; and

chemically treating the polymer particles to form a solid in the form of a three-dimensional, solid conglomerate of polymer particles containing a pore system.

16. The process according to claim 15, wherein a solvent is passed through the powder of the polymer particles under vacuum, whereby the polymer particles adhere to one another and form the conglomerate.

17. The process according to claim 16, wherein acetone vapors are used as the solvent.

21. A process for preparing bone cement comprising:

converting polymer particles into a conglomerate in the form of a solid comprising a pore system; and

adding a monomer to the conglomerate.

31. The process of claim 21 further comprising the step of mixing the monomer with the conglomerate.

32. Bone cement made according to the process of claim 21.