Background: S1 nerve roots are difficult to approach during percutaneous procedures for the diagnostic and treatment procedures of low back pain with radicular symptoms. This is harder in older patients with obscure anatomies, due to the low bone density with overimposing degenerative changes in the facets and deformations. The otherwise straightforward procedure for the lumbar nerve roots, placing the needle in the proximity of the S1 under fluoroscopic guidance, becomes quite a challenge. Case presentation: In the proposed technique, the initial target for the needle is the lower part of the S1 facet in the convergent trajectory of the needle. After achieving contact with the bone the tip of the needle is moved caudally as, in proximity, it reaches the dorsal foramina of the S1/S2 segment-this is named "wandering to the hole". The convergent trajectory of the needle ensures the success of the procedure with a minimal risk of intravenous drug administration, which is characteristic for the suprapedicular technique. Conclusions: The proposed technique is straightforward and reproducible due to the combination of the understanding of the surgical and radiological anatomy of this region, in spite of degenerative changes in the spine.
Keywords: S1 nerve; fluoroscopic-guided localization; lower back pain; lumbar nerve root.