Predictors of Long-Term Response to Ganglion Impar Block With or Without Caudal Epidural Steroid Injection in Chronic Coccydynia: A Retrospective Study.

BACKGROUND

Ganglion impar block (GIB) is a commonly used interventional option for refractory chronic coccydynia. Caudal epidural steroid injection (CESI) targets the sacral and coccygeal roots and may theoretically augment the analgesic efficacy of GIB. Evidence comparing GIB alone with a combined GIB and CESI approach, however, remains limited. This study compared long-term pain outcomes after GIB monotherapy versus GIB combined with CESI.

METHODS

In this retrospective single-center study (Jan 2020-May 2025), we evaluated 56 adults with chronic coccydynia who underwent GIB alone (Group A) or in combination with CESI (Group B). Pain intensity was assessed using the 11-point numeric rating scale (NRS-11) at baseline and at 1 h, 1 month, and 6 months after the procedure. Multivariable logistic regression was used to explore predictors of 6-month response, including early postprocedural pain change and sex.

RESULTS

Significant improvements in pain intensity were observed in both groups and sustained over 6 months. Responder rates at 6 months were comparable between the GIB-only (41.7%) and GIB with CESI (45.0%) groups (p > 0.05). Multivariable analysis revealed that greater early pain relief (baseline to 1 h) significantly predicted 6-month favorable outcomes (OR: 2.08; 95% CI: 1.26-3.42; p = 0.004), whereas male sex was associated with significantly reduced odds of response (OR: 0.11; 95% CI: 0.02-0.72; p = 0.022).

CONCLUSIONS

In this single-center retrospective cohort, GIB was associated with sustained pain relief in a substantial proportion of patients with chronic coccydynia, while the addition of CESI did not confer a clear incremental benefit. Importantly, immediate postprocedural pain relief served as a robust predictor of long-term success, whereas male sex was identified as a negative prognostic factor. Prospective, adequately powered randomized trials are needed to confirm these exploratory findings and to refine patient selection for GIB-based interventions. Trial Registration: ClinicalTrials.gov Identifier: NCT07200765.