A tissue-removing catheter for removing tissue from a body lumen includes a tissue-removing element. The tissue-removing element may be coupled to a first longitudinal portion of the catheter body. An angular-displacement sensor may be coupled to the catheter body for detecting an angular displacement of at least the first longitudinal portion of the catheter body relative to the rotational axis when the first longitudinal body portion is rotated about the rotational axis. The tissue-removing element may be rotatable about a rotational axis to adjust an angular tissue-removing position of the tissue-removing element relative to the body lumen when the catheter body is inserted in the body lumen. An angular-displacement sensor may be generally adjacent the tissue-removing element for detecting an angular displacement of the tissue-removing element relative to the body lumen when the tissue-removing element is rotated about the rotational axis.