Non-neurodestructive ganglion impar blocks for coccydynia and related disorders: a systematic review and meta-analysis

Background/Importance Chronic coccydynia is a challenging condition to manage. Conflicting evidence exists regarding the role of the ganglion impar in coccygeal nociception. When conservative treatments fail, minimally invasive interventions at the ganglion impar may be effective in providing relief. Objectives To evaluate the effectiveness and safety of ganglion impar blocks (GIBs) for the management of chronic coccydynia. Evidence review A systematic review and meta-analysis was conducted following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Relevant studies were identified through a comprehensive literature search of PubMed, Embase Classic+ Embase, CINAHL and the Web of Science in February 2024. Data on patient characteristics, intervention details, pain outcomes (measured by Visual Analog Scale and Numerical Pain Rating Scale) and adverse events were extracted. Meta-analysis was performed using standardized mean differences (SMDs) on scale of 0 to 10. Findings Seventeen studies described 625 coccydynia patients treated with GIB. All studies reported some level of improvement of pain after GIB. The meta-analysis included 11 studies totaling 391 patients with a baseline pain score of 7.93 (7.81 to 8.04 95% CI). GIBs were effective in reducing coccygeal pain at short-term (up to 3 months), intermediate-term (3–6 months) and long-term (greater than 6 months) follow-up. SMDs were −2.73 (95% CI −3.45 to −2.01), −3.22 (95% CI −2.82 to −1.45), −1.86 (95% CI −2.58 to −1.15) at 3 months, 3–6 months and >6 months, respectively. No serious adverse events were noted. Grading of Recommendations Assessment, Development and Evaluation assessment indicated ‘very low’ certainty of evidence across all outcomes. Conclusions Non-neurodestructive GIB may be a safe and potentially effective treatment option for patients with chronic, refractory coccydynia. PROSPERO registration number CRD42024506056.