Background: The sacroiliac (SI) joint is a common cause of low back pain, for which
radiofrequency (RF) denervation has been shown to provide long-term relief. However,
controversy exists surrounding the innervation, which treatment paradigm to utilize, and how
best to select patients who might benefit.
Objective: To describe a patient with terminal breast cancer and tumor infiltration of the
sacroiliac joint who was treated with cooled RF of the sacral lateral branches as an end-oflife palliative measure. The objectives of this review are to provide insight into the innervation
of the SI joint; address controversial issues surrounding the targeted nerves in a patient with
transitional anatomy; outline risk-mitigation strategies; and highlight the need for individually
tailored treatment plans.
Methods: Case-based focused literature review in a patient treated with cooled RF ablation of
the L4-S3 primary dorsal rami and lateral branches.
Results: Treatment was tailored to facilitate the rapid treatment of this terminal patient by
performing the prognostic blocks and RF ablation at the same visit. Until her death 5 days
post-procedure, the patient reported significant pain relief and began to ambulate and use the
bathroom on her own, activities she could not do before treatment. In addition to functional
improvement, she was also able to significantly reduce her opioid intake.
Conclusion: This is the first report of cooled SI joint RF ablation to treat cancer pain. Our patient’s
positive response to the procedure suggests the possibility that the lateral branches innervate
not only the posterior ligaments, but also the bony articulation. The decision to proceed with RF
ablation on the same day as a prognostic lateral branch block was based on our patient’s terminal
condition, and the fact that cooled RF does not require sensory stimulation to ensure proximity to
the target nerves. Because of her transitional anatomy, we elected to target L4.
Key words: Cancer, denervation, innervation, radiofrequency, sacroiliac joint, transitional
anatomy