Efficacy of Combining Caudal Epidural Steroid With Ganglion Impar Block in Chronic Coccydynia

NCT07200765 | Active Not Recruiting

• 1 other identifier: MERSINALG-COCCYDYNIA-2025
• Study Type: observational
• Target: 56
• Locations: 1 country
• Sites: 1

Brief Summary

Coccydynia refers to pain localized to the tailbone (coccygeal) region. Initial management is conservative-nonsteroidal anti-inflammatory drugs (NSAIDs), use of a seat cushion, and physical therapy-yet a proportion of patients remain symptomatic and subsequently pursue interventional options. The ganglion impar block (GIB), originally used to treat perineal cancer pain, is now recognized as an effective approach for perineal and coccygeal pain of both malignant and benign etiologies. Caudal epidural steroid injection (CESI) is also employed, either as monotherapy or in conjunction with other treatments; however, its precise role in coccydynia has not been clearly defined. Evidence directly comparing these injections is limited, and whether the combination confers superiority over GIB alone remains unresolved. In this retrospective study, we will compare GIB alone versus GIB combined with CESI in adults treated for chronic coccydynia refractory to noninterventional management and evaluate any incremental benefit of the combination.

Conditions

Caudal Epidural Block; Coccygodynia; Coccydynia

Keywords

Chronic Coccydynia, Ganglion impar block

Outcome Measures

Primary Outcomes (1)

• Change in NRS-11 pain score from baseline to 6 months

  Within-participant change in pain intensity (ΔNRS = 6-month NRS-11 minus baseline NRS-11); negative values indicate improvement. NRS-11: 0=no pain, 10=worst pain.

  Baseline and 6 months post-procedure

Secondary Outcomes (2)

• Treatment success rate at 6 months (IMMPACT)

  Baseline and 6 months post-procedure

• Change in NRS-11 pain score from baseline to 1 hour

  Baseline and 1 hour post-procedure.

Study Arms (2)

Group A: Ganglion Impar Block

This group includes adults with a diagnosis of chronic coccydynia who underwent a ganglion impar block as part of routine clinical care.The ganglion impar block was performed under fluoroscopic guidance using a transsacrococcygeal approach, with lateral and anteroposterior (AP) views obtained. With the loss-of-resistance technique, the needle was advanced along the intervertebral disc and the ventral tip was positioned anterior to the sacrococcygeal ligament. Needle placement was confirmed by injecting 1 mL of iohexol 350 mg/mL contrast (Omnipaque 350, GE Healthcare, Ireland) into the retroperitoneal space. A total of 5 mL was then administered, consisting of 1 mL methylprednisolone acetate (40 mg/mL), 2 mL normal saline, and 2 mL 0.5% bupivacaine hydrochloride. Outcomes were abstracted from records at baseline, 1 hour, 1 month and 6 month after the procedure.

Group B: Ganglion Impar Block Combined with Caudal Epidural Steroid Injection

This group includes adults with chronic coccydynia who, as part of routine clinical care, received a combined caudal epidural steroid injection and ganglion impar block. The Caudal Epidural Steroid Injection procedure was performed under fluoroscopic guidance with both lateral and anteroposterior (AP) views. After subcutaneous infiltration of 1 mL of 2% lidocaine, a 22-gauge spinal needle was advanced into the caudal epidural space, and correct placement was confirmed by injection of 1 mL of iohexol 350 mg/mL contrast (Omnipaque 350; GE Healthcare, Ireland). A total of 5 mL was then administered, consisting of 40 mg methylprednisolone acetate diluted in 4 mL of normal saline. Following the caudal epidural steroid injection, the ganglion impar block was performed as described for Group A. Outcomes were abstracted from records at baseline, 1 hour, 1 month and 6 month after the procedure.

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)
• Sampling Method: Non-Probability Sample

Study Population

The study population consisted of adults with chronic coccydynia who received either a ganglion impar block (GIB) alone or a combined with caudal epidural steroid injection as part of routine clinical care at the Algology Clinic of Mersin University Hospital between January 1, 2020, and May 20, 2025. Patients were not assigned to treatments by protocol; intervention choice reflected clinician judgment and patient characteristics. Outcomes (e.g., NRS-11 pain scores) were abstracted from medical records at baseline and follow-up.

You may qualify if:

• Age ≥18 years
• Chronic coccydynia \>3 months
• Inadequate response to conservative treatments
• Written informed consent documented for the procedure (per records)

You may not qualify if:

• Active infection on the injection date.
• History of lumbar or coccygeal surgery
• Allergy to local anesthetics or contrast media
• Coagulopathy / anticoagulant therapy contraindicating the procedure
• Inadequate follow-up documentation
• Injection performed to a different region during the indexed procedure

Sponsors & Collaborators

• Mersin University: lead

Study Sites (1)

Mersin University Faculty of Medicine, Department of Algology

Mersin, Mersin, 33110, Turkey (Türkiye)

Location

Study Design

• Study Type: observational
• Observational Model: COHORT
• Time Perspective: RETROSPECTIVE
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Associate Professor

Study Record Dates

• First Submitted: September 23, 2025
• First Posted: October 1, 2025
• Study Start: January 1, 2020
• Primary Completion: October 1, 2025
• Study Completion: November 1, 2025
• Last Updated: October 1, 2025

Record last verified: 2025-09

Data Sharing

• IPD Sharing: Will share
• Shared Documents: STUDY PROTOCOL, SAP
• Time Frame: De-identified individual participant data and selected supporting documents will be available upon request beginning 6 months after publication. Data will remain available for 5 years.
• Access Criteria: Researchers affiliated with academic institutions may request access to anonymized individual participant data and related documents for non-commercial research. Requests must include a brief study proposal and will be reviewed by the principal investigator. Data will be shared via institutional email upon approval.

Locations

TU (1)