ONE-COMPONENT BONE CEMENT PASTES AND METHODS FOR CURING THEM

• US 20090105144A1
• Filed: 10/21/2008
• Published: 04/23/2009
• Est. Priority Date: 10/22/2007
• Status: Active Grant

• Current Assignee: Heraeus Medical GmbH (Heraeus Holding GMBH)
• Original Assignee: Heraeus Medical GmbH (Heraeus Holding GMBH)
• Inventors: VOGT, SEBASTIAN, BUCHNER, HUBERT
• Granted Patent: US 9,387,275 B2
• Time in Patent Office: Days
• US Class Current: 514/1.100
• CPC Class Codes: A61L 24/0089 containing inorganic fillers not covered by groups A61L24/0078 or A61L24/0084
• CPC Class Codes: A61L 24/0094 containing macromolecular fillers
• CPC Class Codes: A61L 2430/02 for reconstruction of bones; weight-bearing implants
• CPC Class Codes: C08L 33/10 Homopolymers or copolymers of methacrylic acid esters

Abstract

One-component bone cement pastes, containing:

• • AI at least one methacrylate monomer that is suited for radical polymerisation;
  • AII at least one polymer that is soluble in AI;
  • AIII at least one particulate polymer that is insoluble in AI and has a particle size of less than 500 μm;
  • optionally AIV at least one initiator that can be activated, in particular at least one radical-forming initiator or at least one radical initiator that is soluble in AI and subject to thermal decomposition;
  • optionally AV at least one electrically conductive radio-opaquer, in particular in the form of ferromagnetic particles;
    are well-suited, e.g., for producing paste-like two-component bone cements, for producing means for the fixation of total endoprostheses and revision endoprostheses, for producing selfcuring filling materials for vertebroplasty, kyphoplasty or femoral neck augmentation, or for producing local agent release systems, and, in the presence of component AV, can be heated through alternating magnetic fields of 500 Hz to 50 kHz or through induction until the decomposition of an initiator AIV commences.

From this also results a method for the curing of pastes containing

• at least one initiator that can be activated, in particular at least one radical-forming initiator or at least one radical initiator that is subject to thermal decomposition; and
• at least electrically conductive particles, in particular ferromagnetic particles;
• whereby the paste is exposed to an alternating magnetic field with a frequency in the range of 500 Hz to 50 kHz, or
• whereby the paste is heated by induction until the decomposition of the initiator commences.

Claims

1. One-component PMMA bone cement paste comprising

(i) at least one methacrylate monomer that is suited for radical polymerisation;

(ii) at least one polymer that is soluble in the methacrylate monomer; and

(iii) at least one particulate polymer that is insoluble in the methacrylate monomer and has a particle size of less than 500 μ

m.

2. Bone cement paste according to claim 1, further comprising

at least one initiator that can be activated.

3. Bone cement paste according to claim 1, further comprising

at least one radical initiator that is soluble in the methacrylate monomer and subject to thermal decomposition;

and

at least one electrically conductive radio-opaquer.

4. Bone cement paste according to claim 3, wherein the radio-opaquer are particles having a particle size of 0.5 to 500 μ

m of cobalt, iron, NdFeB, SmCo, cobalt-chromium steel, zirconium, hafnium, titanium, titanium-aluminium-silicon alloys, or titanium-niobium alloys.

5. Bone cement paste according to claim 3, wherein the radio-opaquer are ferromagnetic particles.

6. Bone cement paste according to claim 1, wherein the mathacrylate monomer is suited for distillation.

7. Bone cement paste according to claim 1, wherein the methacrylate monomer has a boiling point higher than 110°

C.

8. Bone cement paste according to claim 1, comprising 25-50 parts by weight methacrylate monomer/methacrylate monomers to 2-35 parts by weight soluble polymers to 40-70 parts by weight polymer that is insoluble in the methylmethacrylate monomer/methylmethacrylate monomers such that the paste is tack-free and can be stored without changing its volume.

9. Bone cement paste according to claim 1, wherein the soluble polymer is a poly-methylmethacrylate-co-polymer.

10. Bone cement paste according to claim 9, wherein soluble polymer is poly-methylmethacrylate-co-methylacrylate or poly-methylmethacrylate-co-styrene.

11. Bone cement paste according to claim 1, wherein the insoluble polymer is cross-linked poly-methylmethacrylate or cross-linked poly-methylmethacrylate-co-methylacrylate.

12. Bone cement paste according to claim 1, wherein the methacrylate monomer is a bifunctional methacrylate.

13. Bone cement paste according to claim 12, wherein the bifunctional methacrylate is selected from the group consisting of ethylene glycol dimethacrylate, butan-1,3-diol-dimethacrylate, butan-1,4-diol-dimethacrylate, and hexan-1,6-diol-dimethacrylate.

14. Bone cement paste according to claim 1, further comprising at least one barbituric acid derivative as radical-forming initiator.

15. Bone cement paste according to claim 14, further comprising at least one accelerator.

16. Bone cement paste according to claim 15, wherein the accelerator is an organic copper(II) salt.

17. Bone cement paste according to claim 1, further comprising at least one additional radio-opaquer.

18. Bone cement paste according to claim 17, wherein the additional radio-opaquer is selected from the group consisting of zirconium dioxide, barium sulfate, tantalum, and biocompatible calcium salts.

19. Bone cement paste according to claim 1, further comprising at least one pharmaceutical agent from the groups of antibiotics, hormones, growth factors, and antiphlogistics.

20. Bone cement paste according to claim 1, further comprising up to 20 parts by weight of at least one biocompatible elastomer that is particulate or soluble in the methacrylate monomer/methacrylate monomers.

21. Bone cement paste according to claim 20, wherein the biocompatible elastomer is polybutadiene or poly-butadiene-co-styrene.

25. Method for curing a bone cement paste comprising exposing a bone cement paste according to claim 1 to an alternating magnetic field with a frequency in the range of 500 Hz to 50 kHz.

26. Method for curing a bone cement paste comprising heating a bone cement paste according to claim 2 by induction until the decomposition of the initiator commences.

22. (canceled)

23. (canceled)

24. (canceled)

27. (canceled)