Ganglion impar block in patients with chronic coccydynia

Abstract

Introduction: Coccydynia refers to pain in the terminal segment of the spinecaused by abnormal sitting and standing posture. Coccydynia is usually managed conservatively, however in nonresponsive patients, ganglion impar block is used as a good alternate modality for pain relief. This article studies the effect of ganglion impar block in coccydynia patients who were not relieved by conservative management.

Materials and methods: The study was carried out at the pain clinic in the departments of Physical Medicine and Rehabilitation and Radiology in a tertiary centre in India. It was a prospective hospital-based study, in which 35 patients with coccydynia were considered for fluoroscopy-guided trans-sacro-coccygeal ganglion impar block. The outcome assessment was done using Numerical Rating Scale (NRS) and Oswestry Disability Index (ODI) scores for a follow-up period of 6 months. Of the 35 patients, 4 were lost to follow-up. Analysis was done usingthe data from the remaining 31 patients.

Results: The mean age of the patients suffering from chronic coccydynia was 42.9 ± 8.39 years, and patients' age range was 28-57 years. The mean score of NRS and ODI before the procedure was 7.90 ± 0.16 and 48.97 ± 1.05, respectively. The interquartile range (IQR) of NRS score remained almost unchanged during pre and postprocedure, however, IQR of ODI varied during the pre and post procedural events. The NRS and ODI scores immediately after the procedure decreased drastically showing significant pain relief in patients, and the difference of scores till the end of study was statistically significant.

Conclusion: This study recommends the trans-sacro-coccygeal "needle inside needle" technique for local anesthetic block of the ganglion impar for pain relief in patients with coccydynia. This should be integrated with rehabilitative measures including ergonomical modification for prolonging pain free period.

Keywords: Coccydynia; NRS score; ODI score; ganglion impar block.

Figure 1

Lateral fluoroscopic view with a pointer placed on the skin surface (black arrow) to mark the sacro-coccygeal joint (white arrow)

Figure 2

Needle position (black arrow) for injection of the local anaesthetic steroid mixture into the ganglion impar. Before injection of the mixture, a small amount of contrast is injected which forms a ‘comma’ like appearance (white arrow) in front of the sacro-coccygeal joint indicating the location of the ganglion impar