A tissue-removing catheter includes a sensor configured to detect a parameter of the catheter during the cutting operation of the catheter when a tissue-removing element is in a tissue-removing position. A locking control circuit is in electrical communication with the sensor and a locking device. During an operational control function, the locking control circuit receives a signal from the sensor based at least in part on the parameter of the catheter detected during the cutting operation of the catheter. The locking control circuit determines whether the received signal is indicative of a tissue-removing element engaging a non-tissue obstruction. The locking control circuit configures the locking device in its locked configuration to inhibit movement of the tissue-removing element from its tissue-removing position to its neutral position if the received signal is indicative of the tissue-removing element engaging a non-tissue obstruction.