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US 5,328,262 AGranted
Method for producing reduced porosity bone cement
AssigneeMit
InventorsLars A. A. Lidgren, Lars G. Dahl
Life of this patent
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AssigneeMit
InventorsLars A. A. Lidgren, Lars G. Dahl
Estimating the term…
A method for producing bone cement by mixing components forming part thereof, whereby mixing occurs in vacuum in a mixing device (1) and whereby ready-mixed bone cement (2) is collected in the mixing device (1) before it is ejected or discharged therefrom. For reducing the volume of porosity of the pores formed in the bone cement (2) during collection, the bone cement (2) is collected in vacuum to provide vacuum in those pores in the bone cement (2) which are formed during collection, whereby the volume of porosity in the bone cement (2) is reduced when the bone cement is subjected to atmospheric pressure after collection. A device for carrying out this method comprises a movable member (6), preferably a movable piston, which is adapted for pressing out or discharging bone cement (2) from the mixing device (1), which is fixedly mounted for maintaining its position when bone cement (2) is mixed in vacuum and which is releasable such that it can be sucked into the mixing device (1) towards a discharge opening (13 ) when vacuum prevails in said mixing device (1) for collecting or gathering bone cement (2) in said mixing device (1) closest to the discharge opening (13).
A method for producing bone cement by mixing components forming a part thereof, said method comprising the steps of (1) mixing said components under vacuum in a mixing space of a mixing device, whereby clumps of bone cement adhere to an inner wall surface of said mixing space, and (2) collecting said clumps of bone cement in said mixing space close to a discharge opening which is adapted to discharge bone cement from said mixing space, wherein said collecting step includes the steps of (a) exposing said bone cement in said mixing space to vacuum, and (b) moving a piston through said mixing space towards said discharge opening to collect said bone cement near said discharge opening, thereby providing vacuum in those pores in said bone cement which are formed during collection of the bone cement clumps, whereby said pores formed in said bone cement are reduced in size when said bone cement is ultimately subjected to atmospheric pressure after collection.
Dependencies are inferred from the claim text.