Technical Efficacy of a Direction Specific Radiofrequency Device in the Performance of Lumbar Medial Branch Neurotomies

Patients will be placed in a prone position and prepped. The C-arm will be adjusted to establish a true anteroposterior image of the target vertebra. The C-arm will then be rotated until the target point at the base of the SAP is clearly visualized. The Nimbus probe, with the tines (filaments) in the retracted position, will be inserted and advanced to the bony target site using a down the beam approach. The probe hub will be rotated to accomplish a full deployment of the tines with a medial or lateral angular bias, as dictated by the SAP anatomy and angle of entry of the NMEE probe. Motor stimulation at 2 Hz up to 2 volts will be administered (safety check). The lesion site will be anesthetized before the radiofrequency (RF) generator is set to achieve a temperature of 80°C for 80 seconds, following 30 second temperature ramp up. Impedance and power will be recorded.