Abstract: A mixing device for producing reduced porosity bone cement. The device having a movable member (6), preferably a movable piston, which is adapted to press out or discharge bone cement (2) from the mixing device (1). The piston is fixedly mounted in the mixing device. The piston maintains its position when bone cement (2) is mixed in a mixing space in the mixing device. The mixing device is under a vacuum during mixing. After mixing, the piston is released such that it can be drawn into the mixing device (1) toward a discharge opening (13) by a vacuum prevailing in the mixing device (1). The moving piston is used for collecting clumps of bone cement (2) in the mixing device (1) adjacent to the discharge opening (13). By collecting the clumps of bone cement by the moving piston (6) under a vacuum, the porosity of the bone cement (2) is reduced.

Abstract: 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.