An apparatus includes a handle, an elongate shaft assembly, an adjustment feature, and a position sensor. The shaft assembly includes an outer tube and an inner shaft. The outer tube is slidably disposed within an elongate body of the handle. The outer tube extends distally from the elongate body to an outer tube distal end. The inner shaft is coaxially disposed within the outer tube and extends distally through the outer tube end to an inner shaft distal tip. The inner shaft is sized and configured to pass through passageways within an ear, nose, or throat of a patient. The adjustment feature is slidably disposed relative to the body of the handle and is configured to translate at least the outer tube relative to the handle. The position sensor is configured to generate signals indicating a real-time position of the distal tip of the inner shaft.