A manual mixer serves to facilitate mixing and agitating materials for use during surgery. For example, the manual mixer includes a body portion defining an interior area, a mixing assembly provided in the interior area of the body portion, a crank assembly for actuating the mixing assembly, and a valve assembly. The mixing assembly serves to mix and agitate the materials provided in the interior through rotation of a plunger portion and a spring attached thereto, and through upwards and downwards movement of the plunger portion in the interior area. Rotation of the crank assembly serves to rotate the plunger portion and the spring attached thereto, and effectuate upwards and downwards movement of the plunger portion. The valve assembly can be opened to facilitate dispensing of the materials from the interior area.