Vacuum mixing system and method for the mixing of polymethylmethacrylate bone cement

Patent metadata

Field	Value
Publication number	US-2016015854-A1
Application number	US-201514755137-A
Country	US
Kind code	A1
Filing date	Jun 30, 2015
Priority date	Jul 15, 2014
Publication date	Jan 21, 2016
Grant date	—

Abstract

A vacuum mixing system for the mixing of polymethylmethacrylate bone cement comprising at least one cartridge ( 4 ) having an evacuatable internal space ( 5 ) for the mixing of the bone cement, the internal space ( 5 ) of which comprises a cylindrical swept volume, a mixing element ( 12 ) that is arranged in the internal space ( 5 ) of the cartridge ( 4 ) such as to be mobile and can be operated from outside the vacuum mixing system in order to mix the content in the internal space ( 5 ) of the cartridge ( 4 ), and a dispensing plunger ( 2 ) having a cylindrical external circumference whose first base surface borders a base surface of the internal space ( 5 ) of the cartridge ( 4 ) and which can be or is locked to the cartridge ( 4 ) in detachable manner and which, in the detached state, is mobile in the cylindrical region of the internal space ( 5 ) of the cartridge ( 4 ).

First claim

1 . Vacuum mixing system for the mixing of polymethylmethacrylate bone cement, comprising
at least one cartridge ( 4 , 104 ) having an evacuatable internal space ( 5 , 105 ) for the mixing of the bone cement, whereby the internal space ( 5 , 105 ) comprises a cylindrical swept volume, a mixing element ( 12 , 112 ) that is arranged in the internal space ( 5 , 105 ) of the cartridge ( 4 , 104 ) such as to be mobile and can be operated from outside the vacuum mixing system in order to mix the content in the internal space ( 5 , 105 ) of the cartridge ( 4 , 104 ), and a dispensing plunger ( 2 , 102 ) having a cylindrical external circumference whose first base surface borders a base surface of the internal space ( 5 , 105 ) of the cartridge ( 4 , 104 ) and which can be or is locked to the cartridge ( 4 , 104 ) in detachable manner and which, in the detached state, is mobile in the cylindrical region of the internal space ( 5 , 105 ) of the cartridge ( 4 , 104 ), whereby a gas-permeable and particle-impermeable feedthrough ( 1 , 101 ) is arranged in the dispensing plunger ( 2 , 102 ) or a feedthrough ( 1 , 101 ) is formed between the dispensing plunger ( 2 , 102 ) and the internal wall of the internal space ( 5 , 105 ), whereby the feedthrough ( 1 , 101 ) extends from an opening in the jacket surface of the dispensing plunger ( 2 , 102 ) to an opening in the first base surface of the dispensing plunger ( 2 , 102 ).

2 . Vacuum mixing system according to claim 1 , wherein
the dispensing plunger ( 2 , 102 ) comprises at least one circumferential seal ( 20 , 120 ) that seals the internal space ( 5 , 105 ) of the cartridge ( 4 , 104 ) with respect to the outside, optionally having at least one circumferential seal ( 20 , 120 ) arranged between a second base surface of the dispensing plunger ( 2 , 102 ), which is situated opposite from the first base surface of dispensing plunger ( 2 , 102 ), and the opening in the jacket surface of the dispensing plunger ( 2 , 102 ).

3 . Vacuum mixing system according to claim 1 , wherein
one of the jacket surfaces of the cartridge wall of the cartridge ( 4 , 104 ) comprises an opening ( 143 ), which overlaps with the opening in the jacket surface of the dispensing plunger ( 2 , 102 ) while the dispensing plunger ( 2 , 102 ) is in an opened position, and by means of which the internal space ( 5 , 105 ) is or can be connected in gas-permeable manner to the surroundings of the vacuum mixing system.

4 . Vacuum mixing system according to claim 3 , wherein
a closure element ( 144 ) is arranged on the external wall of the cartridge ( 4 , 104 ) by means of which the opening ( 143 ) in the wall of the cartridge ( 4 , 104 ) can be closed, optionally a closure element ( 144 ) arranged on the external wall of the cartridge ( 4 , 104 ) that can be shifted in axial direction of the cartridge ( 4 , 104 ).

5 . Vacuum mixing system according to claim 4 , wherein
the closure element ( 144 ) is a circumferential cuff ( 144 ) that touches, to fit, against the external wall of the cartridge ( 4 , 104 ) and can be shifted in axial direction of the cartridge ( 4 , 104 ) in order to cover and thus close the opening ( 143 ) in the wall of the cartridge ( 4 , 104 ), whereby, optionally, at least one handle part ( 146 ) is fastened on the cuff ( 144 ) and is provided for manual shifting of the cuff ( 144 ) on the external wall of the cartridge ( 4 , 104 ).

6 . Vacuum mixing system according to claim 1 , wherein
the dispensing plunger ( 2 , 102 ), in a first lockable position, projects from the cartridge ( 4 , 104 ) such that the opening in the jacket surface of the dispensing plunger ( 2 , 102 ) is open, and in that the dispensing plunger ( 2 , 102 ), in a second lockable position, is arranged deeper in the internal space ( 5 , 105 ) of the cartridge ( 4 , 104 ) such that the opening in the jacket surface of the dispensing plunger ( 2 , 102 ) is closed by the internal wall of the cartridge ( 4 , 104 ).

7 . Vacuum mixing system according to claim 6 , wherein
a circumferential sealing element ( 20 , 120 ) is arranged between the opening in the jacket surface of the dispensing plunger ( 2 , 102 ) and the second base surface of the dispensing plunger ( 2 , 102 ), which is situated opposite from the first base surface of the dispensing plunger ( 2 , 102 ).

8 . Vacuum mixing system according to claim 1 , wherein
a gas-permeable particle filter ( 22 , 122 ), in particular a pore filter ( 22 , 122 ), is arranged in the feedthrough ( 1 , 101 ) and/or at the opening to the feedthrough ( 1 , 101 ) in the jacket surface of the dispensing plunger ( 2 , 102 ) and/or at the opening to the feedthrough ( 1 , 101 ) in the first base surface of the dispensing plunger ( 2 , 102 ), whereby the gas-permeable particle filter ( 22 , 122 ) is preferred to be impermeable for particles having a diameter of more than 1 μm, particularly preferably for particles having a diameter of more than 5 μm.

9 . Vacuum mixing system according to claim 1 , wherein
the dispensing plunger ( 2 , 102 ) is gas-tight on its side that points from the interior of the cartridge ( 4 , 104 ), except for a vacuum feedthrough ( 36 , 136 ).

10 . Vacuum mixing system according to claim 1 , wherein
the dispensing plunger ( 2 , 102 ) comprises, on the first base surface, a gas-permeable pore disk ( 22 , 122 ) that is supported by ribbing.

11 . Vacuum mixing system according to claim 1 , wherein
the dispensing plunger ( 2 , 102 ) can be pushed axially into the cartridge ( 4 , 104 ) in order to dispense a bone cement dough, that has been mixed from a bone cement powder and a monomer liquid, through a dispensing opening on an end of the cartridge ( 4 , 104 ) opposite from the dispensing plunger ( 2 , 102 ), whereby the dispensing plunger ( 2 , 102 ) optionally can be pushed axially into the cartridge ( 4 , 104 ) after detaching a locking mechanism.

12 . Vacuum mixing system according to claim 1 , wherein
a dispensing opening of the cartridge ( 4 , 104 ) comprises a connecting thread ( 8 , 108 ).

13 . Vacuum mixing system according to claim 1 , wherein
the mixing element ( 12 , 112 ) is arranged on a rod ( 10 , 110 ) that is guided through a gas-tight passage into the interior of the cartridge ( 4 , 104 ), and the mixing element ( 12 , 112 ) is mobile by pushing it in and out of the cartridge ( 4 , 104 ) and by rotating it in the cartridge ( 4 , 104 ), whereby the rod ( 10 , 110 ) optionally comprises a predetermined breakage site at which the rod ( 10 , 110 ) can be broken off near the passage once it has been pulled out of the cartridge ( 4 , 104 ).

14 . Vacuum mixing system according to claim 1 , wherein
the vacuum mixing system comprises a glass container for monomer liquid, and the cartridge ( 4 , 104 ) contains a cement powder, whereby an opening element for opening of the reservoir container is provided, and the cartridge ( 4 , 104 ) is or can be connected via a conduit to the opened reservoir container.

15 . Vacuum mixing system according to claim 14 , wherein
the vacuum mixing system comprises a base element, whereby the base element stores the cartridge ( 4 , 104 ), the reservoir container, and the opening element.

16 . Vacuum mixing system according to claim 15 , wherein
the base element comprises a coupling means for a non-positive fit- and/or positive fit-like connection to the connecting means ( 8 , 108 ) on the dispensing opening of the cartridge ( 4 , 104 ).

17 . Vacuum mixing system according t

Assignees

• Heraeus Medical Gmbh

Inventors

• Vogt Sebastian

Classifications

• A61B2017/8838

  for mixing bone cement or fluid fillers · CPC title

• A61L24/06 Primary

  obtained by reactions only involving carbon-to-carbon unsaturated bonds {(A61L24/043, A61L24/046 take precedence)} · CPC title

• A61B17/8827

  with filtering, degassing, venting or pressure relief means · CPC title

• B29K2033/12

  Polymers of methacrylic acid esters, e.g. PMMA, i.e. polymethylmethacrylate · CPC title

• B29B7/24

  for feeding · CPC title