A medical device for removing or manipulating tissue of a subject is provided with a distal housing having an end effector, and an elongate member configured to introduce the distal housing to a target tissue site of the subject. The elongate member may have proximal and distal portions interconnected by a joint mechanism that is configured to allow the two portions to articulate relative to one another. In some embodiments, the joint mechanism includes one or more nested crown gear(s) configured to drive associated spur gear(s) to accomplish the articulation. In some embodiments, the end effector is a powered scissors device.
