A smart screw according to an embodiment may comprise: a screw main body which penetrates an artificial joint including a shell disposed on a hip joint of an object and a liner disposed on the inner surface of the shell and is then inserted into the hip joint; a transducer including a coupling layer that senses a sound wave signal reflected from the liner, a piezo-electric layer formed to determine a frequency of the sound wave signal, and a sound absorbing layer for absorbing the sound wave signal; and a processing module for generating a sound wave signal toward the liner and receiving the sound wave signal sensed by the coupling layer, measuring the thickness of the liner on the basis of the received sound wave signal, and transferring data about the measured thickness of the liner to the outside.