Selection criteria include radicular pain for more than 6 months with no response to conservative treatment, with no indication for surgical intervention.
Technique:
The patient is placed supine, with the RF probe is placed in the dorsal quadrant of the cervical foramen under fluoroscopy. Electrical stimulation that ensures the probe is not close to other nearby neurologic structures. Sensory and motor stimulation is performed as a safety precaution and to improve the success rate of the procedure.
The voltage at which the patient first perceives the stimulation in the appropriate dermatome is the sensory threshold. This threshold is usually around 0.4–0.7 V when the tip of the needle is next to the medial branch nerve using a frequency of 50 Hz. The frequency is changed to 2 Hz for motor stimulation, and the voltage intensity has to increase to at least twice the sensory threshold before motor activity in the myotomal distribution is typically seen.
Lesions are created from 2 to 4 min at 42°C.
