Method of bone cement preparation

• US 6,709,149 B1
• Filed: 06/14/2001
• Issued: 03/23/2004
• Est. Priority Date: 12/14/1998
• Status: Expired due to Term

• Current Assignee: AO Research Institute Davos
• Original Assignee: AO Research Institute Davos
• Inventors: Tepic, Slobodan
• Primary Examiner(s): Cooley, Charles E.
• Assistant Examiner(s): SORKIN, DAVID L
• Application Number:
  US09/868,116
• Time in Patent Office: 1,013 Days
• Field of Search: 366/139, 366/163.1, 366/348, 523/116, 606/92-94
• US Class Current: 366/139
• CPC Class Codes: A61B 17/8827 with filtering, degassing, venting or pressure relief means
• CPC Class Codes: A61F 2/468 Testing instruments for artificial joints for testing non-implantable prostheses A61F2/76
• CPC Class Codes: A61F 2002/4685 by means of vacuum
• CPC Class Codes: A61L 24/00 Surgical adhesives or cements; Adhesives for colostomy devices
• 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: B01F 2101/20 Mixing of ingredients for bone cement
• CPC Class Codes: B01F 23/565 by introducing liquids in solid material, e.g. to obtain slurries
• CPC Class Codes: B01F 33/5011 portable during use, e.g. hand-held
• CPC Class Codes: B01F 35/71 Feed mechanisms with proportioning B01F35/80
• CPC Class Codes: B01F 35/7164 the containers being placed in parallel before contacting the contents
• CPC Class Codes: B01F 35/718 using vacuum, under pressure in a closed receptacle or circuit system
• CPC Class Codes: C08L 33/12 Homopolymers or copolymers of methyl methacrylate

Abstract

A method of bone cement preparation from a polymeric powder and a liquid component including a polymerisable monomer or comonomer by the action of a catalytic system. Particles of the powder are packed in a powder container having an inlet and an outlet port, while the liquid component is held in a liquid container. The liquid container is connected to te inlet port and a vacuum source is connected to the outlet port. A voided space between the powder particles is flooded by the liquid component that flows form the inlet port toward the outlet port under the influence of the vacuum source.

Claims

1. A method of bone cement preparation from a polymeric powder and a liquid component, comprising a polymerisable monomer or comonomer, by action of a catalytic system, whereby particles of said powder component are packed in a powder container (7;

35) with an inlet port (8) and an outlet port (9) and the liquid component is held in a liquid container (11), comprising the steps of;

A) completely filling said powder container (7;

35) with said polymeric powder;

B) connecting said liquid container (11) to said inlet port (8);

C) connecting a vacuum source (10) to said outlet port (9); and

,

D) completely flooding a void space between said particles of said powder component with said liquid component, said liquid component flowing from said inlet port (8) toward said outlet port (9) by the action of the vacuum source (10).

2. The method according to claim 1, wherein the catalytic system comprises benzoyl peroxide.

3. The method according to claim 1, wherein said upstream inlet port (8) and said downstream outlet port (9) of said container (7) allow air and liquid to pass therethrough, but not powder.

4. The method according to claim 1, wherein said powder container (7;

35) is inflexible and in the form of a syringe (13).

5. The method according to claim 1, wherein said powder in said powder containing compartment (35) is packed to a fractional porosity of 0.34 to 0.38.

6. The method according to claim 5, wherein said powder in said powder containing compartment (35) is packed to a fractional porosity of 0.35 to 0.37.

7. The method according to claim 1, wherein said powder component is flooded by said liquid component in 15 to 60 seconds.

8. The method according to claim 7, wherein said powder component is flooded by said liquid component in 25 to 35 seconds.

9. The method according to claim 1, wherein the flow of said liquid component is controlled by a valve (12) interposed between said liquid container (11) and said inlet port (8).

10. The method according to claim 1, wherein flooding of said powder component by said liquid component is followed by swelling, draining of excess liquid component and extrusion of the mixed components.

11. The method according to claim 10, wherein said draining of excess liquid is effected by a piston (39) contained in a vacuum pump (37).

12. The method according to claim 1, wherein said inlet port (8) comprises a mesh (19) which prevents passage of said powder particles, but allows passage of said liquid.

13. The method according to claim 1, wherein said outlet port (9) comprises a narrow gap (25) that subsequently blocks passage of said powder particles, but allows for passage of air and said liquid.

14. The method according to claim 13, wherein the narrow gap (25) is smaller than 50 μ

.

15. The method according to claim 13, wherein the narrow gap (25) is smaller than 3 times an average diameter of said particles of said powder component.

16. The method according to claim 1, wherein said polymerisable monomer or comonomer comprises methyl-methacrylate, ethyl-methacrylate or butyl-methacrylate or mixtures thereof.

17. The method according to claim 1, wherein said vacuum source (10) generates a vacuum in the range of 10 to 200 mbar.

18. The method according to claim 17, wherein the vacuum source (10) generates a vacuum in the range of 50 to 100 mbar.

19. A method of bone cement preparation from a polymeric powder and a liquid component, comprising a polymerisable monomer or comonomer, by action of a catalytic system, whereby particles of said powder component are packed in a powder container (7;

35) with an inlet port (8) and an outlet port (9) and the liquid component is held in a liquid container (11), comprising the steps of;

A) packing said powder in said powder container (7;

35) to a fractional porosity of 0.30 to 0.43;

B) connecting the liquid container (11) to said inlet port (8);

C) connecting a vacuum source (10) to said outlet port (9); and

,

D) flooding the void space between said particles of said powder component by said liquid component, said liquid component flowing from said inlet port (8) toward said outlet port (9) by the action of the vacuum source (10).