Cervical radiofrequency neurotomy (aka ablation, lesioning or denervation) (RFN) is typically performed after significant pain relief is documented with diagnostic medial branch blocks (MBB). The approach to cervical RFN is posterior. The electrode tip is placed so that the neurotomy occurs parallel to the nerve. Because there is anatomic variation with regard to the course of the medial branch (MB) nerve, many practitioners perform two to four denervations at each level. The practitioner must assess the size of the articular pillar (ArP) of the target zone and according to the size of the electrode utilized, calculate the amount of lesions required to fill the target zone with lesions.

In this chapter, we describe a pragmatic trajectory. Some (i.e., Spine Intervention Society ² ) recommend that both sagittal and oblique passes be performed at each segment, with the exception of the C7 MB, which requires only a sagittal pass. Electrode depths for sagittal and oblique passes differ, and tilt varies per segment targeted.

The third occipital nerve courses transversely across the lateral margin of the C2-C3 joint. The C8 MB location is similar to the T1-T3 MB nerves over the superolateral transverse process of the inferior level. (Frank Willard, PhD, Anatomist, personal communication) (see Thoracic Zygapophysial Joint [Facet] Procedures Chapter 22B , Chapter 22C ).

This chapter focuses mostly on RFN; however, the same posterior approach, although less commonly used, is also suited for MBB. The final electrode-tip position differs for RFN versus MBB posterior approach. With RFN, the goal is to make lesions parallel to the entire accessible length of the MB as it winds its way around the curved ArP. The 30-degree oblique pass targets the MB associated with the anterior third of the pillar, and the parasagittal pass targets the MB associated with the mid third of the pillar. Thus, a more ventral electrode placement is utilized for the 30-degree oblique pass, and a more dorsal placement is utilized for the parasagittal pass.

This differs from a cervical MBB, where the needle tip should overlie the midpoint (centroid) of the pillar. With MB neurolysis, multiple lesions are created in a zone, whereas the target for cervical MBB is a single point where the injectate volume is placed. In both procedures, the lesion zones or injectate volumes, respectively, encompass the known variable locations of the targeted nerves.

When cervical RFN is performed, the electrode is placed using a trajectory view and advanced using multiplanar imaging, with an emphasis on safely using the lateral and contralateral (foraminal) oblique (see Chapter 3 ) views to confirm the depth. After electrode depth location is confirmed and just prior to denervation, 0.5 to 1 cc of anesthetic is injected through the electrode to anesthetize the MB, periosteum, and soft tissues. The time and duration of the denervation vary with different practitioners (e.g., two to four 90-second cycles at 80°C to 85°C).

Special attention should be paid to Chapter 30H , which illustrates the variability of the cervical MB nerves’ anatomic courses and demonstrates recommended RF electrode positions and lesion “zones.”