A medical instrument for delivering electrotherapy to tissue that includes an outer support member having a ground plate at a distal end of the outer support member, and a protrusive element having a tip that extends beyond the ground plate. A portion of the protrusive element proximate the ground plate can act as an electrical insulator and a portion of the protrusive element proximate the distal end of the protrusive element can include a first electrode. The protrusive element can be designed to penetrate into tissue below a tissue surface while a tissue contacting surface of the ground plate rests against the tissue surface. Also disclosed are systems incorporating the medical instrument and methods of electrotherapy to subsurface tissue using the medical instrument.