2. Intervention

Ganglion impar blockade was conducted with the aid of a fluoroscope by a pain medicine expert with at least 10 years of experience in this field. The patients were made to lie down in a prone position and their intergluteal regions were made aseptic. After the sacrococcygeal joint was visualized with the fluoroscope, local anaesthesia was applied at the sacrococcygeal junction via 3 mL 2% prilocaine, and the infiltration was applied to both cutaneous and subcutaneous tissues. The sacrococcygeal joint was pierced with a 22-gauge spinal needle and the ganglion impar was reached. After a 1 mL injection of non-ionic contrast medium, there was dye dispersion, and an image of an “inverse comma” was detected in the lateral visualization; 3 mL 0.5% bupivacaine, 2 mL of saline, and 40 mg of methylprednisolone were injected into the patients in group SL. Only 3 mL 0.5% of bupivacaine and 2 mL of saline were injected to the patients in group L.