Abstract: A transducer assembly (10, 20, 80, 90) is used with an apparatus (100, 200) for detecting the stability of a bone implant (30). The transducer assembly uses one or more transducers to excite vibrations in said bone implant and to detect a response to the vibrations. A coupling (80) is used to detachably connect the one or more transducers to circuitry for driving the vibrations and detecting the response. A memory device (90) is provided within the transducer assembly. The memory device (90) can store one or more parameters read from outside of the transducer assembly via the coupling for controlling the use of the transducer.