PMMA bone paste mixing apparatus and method

Patent metadata

Field	Value
Publication number	US-8960991-B2
Application number	US-201113012349-A
Country	US
Kind code	B2
Filing date	Jan 24, 2011
Priority date	Jan 26, 2010
Publication date	Feb 24, 2015
Grant date	Feb 24, 2015

Abstract

A device is provided with which it is possible to produce poly(methyl methacrylate) bone-cement paste, which is degassed to the greatest extent possible, while avoiding large-volume mixing containers and large cement volumes contained therein. The device includes a tubular hollow body ( 10 ) having a first opening ( 30 ) on the input side and a second opening ( 20 ) on the output side, at least one rotatably-mounted shaft ( 40 ) arranged in the axial direction in the tubular hollow body ( 10 ), thread turns ( 50 ) arranged axially along the outer side of the shaft ( 40 ), wherein the shaft ( 40 ) has at least one section with thread turns ( 50 ) whose pitch decreases in the direction of the second opening ( 20 ), at least one stirring blade ( 60 ) arranged on the shaft ( 40 ), and rigid mixing elements ( 70 ) arranged on the inner side of the tubular hollow body ( 10 ).

First claim

We claim:

1. A device for production of poly(methyl methacrylate) bone-cement pastes from a powder-like cement component A and a liquid monomer component B, the device comprising:
a tubular hollow body ( 10 ) having a first opening ( 30 ) on an input side and a second opening ( 20 ) on an output side,
at least one rotatably-mounted shaft ( 40 ) arranged in an axial direction in the tubular hollow body ( 10 ),
thread turns ( 50 ) arranged axially along an outer side of the at least one shaft ( 40 ), wherein the shaft ( 40 ) has at least one section having thread turns ( 50 ) whose pitch decreases in a direction of the second opening ( 20 ), and wherein an outer diameter of the thread turns ( 50 ) is equal at a maximum to an inner diameter of the tubular hollow body ( 10 ),
at least one stirring blade ( 60 ) arranged on the at least one shaft ( 40 ), and
rigid mixing elements ( 70 ) arranged on an inner side of the tubular hollow body ( 10 ).

2. The device according to claim 1 , wherein the tubular hollow body ( 10 ) is arranged vertically, the first opening ( 30 ) bounds the tubular hollow body ( 10 ) at a top, and the second opening ( 20 ) bounds the tubular hollow body ( 10 ) at a bottom.

3. The device according to claim 1 , wherein the tubular hollow body is constructed at the second opening ( 20 ) as a nozzle tube ( 80 ).

4. The device according to claim 1 , wherein the opening ( 30 ) is closed with a cap ( 90 ) having at least one bushing ( 91 ) for the at least one shaft ( 40 ), a first supply opening ( 100 ) for the powder-like cement component A, and a second supply opening ( 110 ) for the liquid monomer component B.

5. The device according to claim 1 , wherein the at least one stirring blade ( 60 ) is oriented such that, through rotational movements of the at least one shaft ( 40 ), a cement mixture C to be mixed is moved in the direction of the second opening ( 20 ).

6. The device according to claim 1 , wherein the thread turns ( 50 ) are arranged such that a cement mixture C to be mixed is moved by rotational movements of the at least one shaft ( 40 ) in the direction of the second opening ( 20 ).

7. A method for production of poly(methyl methacrylate) bone-cement pastes from a powder-like cement component A and a liquid monomer component B using a device comprising:
a tubular hollow body ( 10 ) having a first opening ( 30 ) on an input side and a second opening ( 20 ) on an output side, a first supply opening ( 100 ) for the powder-like cement component A, and a second supply opening ( 110 ) for the liquid monomer component B,
at least one rotatably-mounted shaft ( 40 ) arranged in an axial direction in the tubular hollow body ( 10 ),
wherein the first opening ( 30 ) is closed with a cap ( 90 ) having at least one bushing ( 91 ) for the at least one shaft ( 40 ),
thread turns ( 50 ) arranged axially along an outer side of the at least one shaft ( 40 ), wherein the shaft ( 40 ) has at least one section having thread turns ( 50 ) whose pitch decreases in a direction of the second opening ( 20 ),
at least one stirring blade ( 60 ) arranged on the at least one shaft ( 40 ), and
rigid mixing elements ( 70 ) arranged on an inner side of the tubular hollow body ( 10 ),
the method comprising:
continuously introducing the powder-like cement component A through the first supply opening ( 100 ) and the liquid monomer component B through the second supply opening ( 110 ) into the tubular hollow body ( 10 ),
mixing the powder-like cement component A and the liquid monomer component B such that a paste-like cement mixture C is formed by swelling,
causing axial rotational movements of the shaft ( 40 ), such that a mass flow of the paste-like cement mixture C is generated from the first opening ( 30 ) in the direction of the second opening ( 20 ), and
pressing the cement mixture C out from the second opening ( 20 ).

8. The method according to claim 7 , wherein the powder-like cement component A is mixed with the liquid monomer component B at a temperature in a range of −30° C. to +60° C. within 5 to 20 minutes, such that the paste-like cement mixture C is produced continuously.

9. The method according to claim 7 , wherein the mixing is carried out such that, during the mixing, dissolving processes and swelling processes take place in the paste-like cement mixture C.

10. The method according to claim 7 , wherein, during the mixing, no radical polymerization is started in the paste-like cement mixture C.

11. The method according to claim 7 , wherein no partial melting or fusion of components of the paste-like cement mixture C takes place.

12. A device for production of poly(methyl methacrylate) bone-cement pastes from a powder-like cement component A and a liquid monomer component B, the device comprising:
a tubular hollow body ( 10 ) having a first opening ( 30 ) on an input side and a second opening ( 20 ) on an output side, wherein the tubular hollow body is constructed at the second opening ( 20 ) as a nozzle tube ( 80 ),
at least one rotatably-mounted shaft ( 40 ) arranged in an axial direction in the tubular hollow body ( 10 ),
thread turns ( 50 ) arranged axially along an outer side of the at least one shaft ( 40 ), wherein the shaft ( 40 ) has at least one section having thread turns ( 50 ) whose pitch decreases in a direction of the second opening ( 20 ),
at least one stirring blade ( 60 ) arranged on the at least one shaft ( 40 ),
rigid mixing elements ( 70 ) arranged on an inner side of the tubular hollow body ( 10 ), and
a slide ( 95 ) arranged in the nozzle tube ( 80 ) perpendicular to a longitudinal axis of the nozzle tube ( 80 ).

13. A device for production of poly(methyl methacrylate) bone-cement pastes from a powder-like cement component A and a liquid monomer component B, the device comprising:
a tubular hollow body ( 10 ) having a first opening ( 30 ) on an input side and a second opening ( 20 ) on an output side, wherein the opening ( 30 ) is closed with a cap ( 90 ) having at least one bushing ( 91 ) for the at least one shaft ( 40 ), a first supply opening ( 100 ) for the powder-like cement component A, and a second supply opening ( 110 ) for the liquid monomer component B, and wherein the cap ( 90 ) has an exhaust-air opening ( 120 ),
at least one rotatably-mounted shaft ( 40 ) arranged in an axial direction in the tubular hollow body ( 10 ),
thread turns ( 50 ) arranged axially along an outer side of the at least one shaft ( 40 ), wherein the shaft ( 40 ) has at least one section having thread turns ( 50 ) whose pitch decreases in a direction of the second opening ( 20 ),
at least one stirring blade ( 60 ) arranged on the at least one shaft ( 40 ), and
rigid mixing elements ( 70 ) arranged on an inner side of the tubular hollow body ( 10 ).

14. A device for production of poly(methyl methacrylate) bone-cement pastes from a powder-like cement component A and a liquid monomer component B, the device comprising:
a tubular hollow body ( 10 ) having a first opening ( 30 ) on an input side and a second opening ( 20 ) on an output side, wherein the opening ( 30 ) is closed with a cap ( 90 ) having at least one bushing ( 91 ) for the at least one shaft ( 40 ), a first supply opening ( 100 ) for the powder-like cement component A, and a second supply opening ( 110 ) for the liquid monomer component B, and wherein the cap ( 90 ) has a gassing opening ( 130 ),
at least one rotatably-mounted shaft ( 40 ) arranged in an axial direction in the tubular hollow body ( 10 ),
thread turns ( 50 ) arranged axially along an outer side of the at least one shaft ( 40 ), wherein the shaft ( 40 ) has at least one secti

Assignees

• Vogt Sebastian
• Büchner Hubert
• Heraeus Medical Gmbh

Inventors

• Vogt Sebastian
• Büchner Hubert

Classifications

• B01F15/0289

  Operations & Transport · mapped topic

• B01F7/00291 Primary

  Operations & Transport · mapped topic

• B01F2215/0029

  Operations & Transport · mapped topic

• B01F7/00391

  Operations & Transport · mapped topic

• B01F27/114

  Helically shaped stirrers, i.e. stirrers comprising a helically shaped band or helically shaped band sections · CPC title