Patent ID: 7645066

Claim:
A method of mixing bone cement, said method including the steps of: placing components forming the bone cement in a housing, the housing being part of a mixer that includes first and second paddles disposed in the housing that are spaced apart from each other, the first paddle having a shaft from which first and second vanes extend, the first vane shaped to have an outer edge in close proximity with an interior wall of the housing and the second vane shaped to have an outer edge spaced from the housing interior wall, the second paddle having a shaft and a vane positioned between the second paddle shaft and the first paddle vanes and positioned to rotate towards and away from the first paddle shaft; simultaneously rotating both the first and second paddles so that, simultaneously: the rotation of the first paddle first vane scrapes the bone cement under formation from the housing interior wall; the rotation of the first paddle second vane smears the bone cement under formation around the housing interior wall; and the rotation of the second paddle vane towards and away from the first paddle shaft pushes the bone cement under formation towards and then away from the first paddle shaft.