Abstract: An extrudable allograft bone tissue material for filling surgical sites can be made from mineralized or demineralized cortical, cancellous, or cortical/cancellous bone powder. A method is disclosed for reconstituting the bone powder in a syringe which includes the steps of placing lyophilized bone material of predetermined mixed size in a syringe barrel having a distal circular opening that ranges in diameter from about 8 mm to about 15 mm and adding a volume of sterile fluid to wet the bone powders. The excess sterile fluid is drained through the bone allowing the fluid to remain in constant engagement with the bone for a period of time until the mass is fully reconstituted from its initial lyophilized state and attains self-adherence so that the mass conforms to the shape of the barrel of the syringe and retains the barrel shape and integrity after extrusion from the syringe into the surgical site in a semisolid mass.