An apparatus for operating a
syringe piston is developed, which is comprised of: a
syringe mounting section for fixedly holding a
syringe, a thread hole formed at an upper head part of the syringe mounting section, and a
piston press unit having a
threaded rod, which is inserted into the thread hole so that the syringe
piston press unit can move up and down along the thread hole, a locking slot for fixedly inserting and retaining the
medicine filled syringe, a semi-
cylindrical tube to assemble with the syringe mounting section. The syringe filled with medical
cement is attached to the syringe mounting section and the syringe piston is moved downward with no reverse movement when the piston press unit is rotated, so the medical
cement contained in the syringe is injected with a
constant pressure, so that a predetermined amount of medical
cement is precisely injected into a patient's body.