The Transverse Process Cluneal Approach (TPCA): First-in-Human Proximal Radiofrequency Ablation of the Superior Cluneal Nerve in a Patient With Clinical Features Consistent With Maigne's Syndrome - A Novel Anatomy-Based Clinical Case.

Background: Superior cluneal nerve (SCN) entrapment is an underrecognized cause of chronic low back and gluteal pain and is frequently misdiagnosed as lumbar radiculopathy or sacroiliac joint dysfunction. Radiofrequency ablation (RFA) of the SCN has been previously described only at the level of the iliac crest. No reports exist on proximal SCN ablation at the level of the lumbar transverse processes. Objective: To describe a novel anatomy-based proximal technique for radiofrequency ablation of the superior cluneal nerve at the level of the L1-L3 transverse processes using the Transverse Process Cluneal Approach (TPCA), and to report the first-in-human clinical outcome. Case Presentation: A 68-year-old female with chronic unilateral lumbogluteal pain refractory to conservative treatment presented with clinical features consistent with thoracolumbar junction syndrome (Maigne's syndrome). Imaging studies showed no structural pathology correlating with symptom severity. A targeted diagnostic block at the lateral border of the L1-L3 transverse processes produced >60% temporary pain relief, supporting the superior cluneal nerve as the primary pain generator (superior cluneal neuralgia). Subsequently, radiofrequency ablation was performed at the same anatomical level under fluoroscopic guidance. Results: The procedure was well tolerated without complications. One month after RFA, pain intensity decreased from 8/10 to 0-1/10 on the visual analog scale, and the Oswestry Disability Index improved from 48% to 10%. At 3-month follow-up, sustained pain relief (VAS ≤2/10), functional improvement, and marked enhancement in quality of life (EQ-5D increase from 0.54 to 0.88) were observed. Conclusion: Proximal radiofrequency ablation of the superior cluneal nerve at the level of the lumbar transverse processes using the TPCA technique appears to be a safe and effective minimally invasive treatment for superior cluneal neuralgia in a patient with clinical features consistent with Maigne's syndrome. This approach enables anatomically precise denervation prior to fascial penetration and may offer an alternative to distal cluneal nerve interventions. Further studies with longer follow-up are warranted to evaluate durability and reproducibility.