A disc surgical system is provided having an elongated tubular member housing and an electrosurgical electrode for excising of or shrinking tissue. The instrument includes at least one cannula having an operative end for entering an operative field of a patient, at least one guide wire having a pointed end for piercing tissue, a tapered dilator configured to slide over a guide wire； and a trephine configured to slide over a guide wire. The operative end has threads on an exterior surface of the cannula for engagement with the tissue of the patient.
