Treatment of chronic refractory coccydynia with peripheral nerve field stimulation: a novel case

Coccydynia or coccyx pain is a rare form of low back pain located below the sacrum and above the anus. The causes of this condition vary, including previous trauma, underlying conditions (such as infection or neoplasm), and idiopathic causes. Our purpose was to describe the successful treatment of chronic refractory coccydynia with the application of sacral area neuromodulation. A 54-year-old female patient had a 9-year history of chronic drug-resistant coccydynia associated with low back pain and right-sided sciatica. Her clinical examination revealed bilateral pain on palpation of the sacroiliac joint areas. Following a successful trial, the patient underwent implantation of a peripheral nerve field stimulation (PNFS) system under local anesthesia. The electrodes were placed bilaterally at the sacroiliac joint area (S1-S2 level), which was the optimal position at the site of maximal pain, and the implantable pulse generator was placed in a subcutaneous pocket at the right gluteal area. She showed significant pain relief immediately postoperatively, became pain-free a few days later, and remained pain-free at 6-month follow-up. Data regarding neuromodulation, and particularly PNFS, as a treatment for coccydynia and other non-specified kinds of low back pain are still limited. Our case is therefore useful to depict this minimally invasive technique as a modern option in the armamentarium of specialists who treat patients suffering from chronic refractory pain syndromes. PNFS seems to be a promising therapeutic option for chronic refractory coccydynia and larger studies are necessary to confirm the value of this finding.