An interventional study of Pulsed Radiofrequency and Conventional Radiofrequency in Back Pain, sponsored by Adana City Training and Research Hospital. Not yet recruiting at 2 sites in Turkey (Türkiye). Open to participants aged 18 Years to 80 Years. Per ClinicalTrials.gov, last updated 2026-03-27.
Sponsored by Adana City Training and Research Hospital · Not applicable, Interventional, and Treatment
The aim of this study is to prospectively evaluate the effects of pulsed and conventional radiofrequency ablation of the ganglion impar on pain, quality of life, and sleep quality in patients with refractory coccydynia, and to determine whether one treatment is superior to the other.
Coccydynia, commonly referred to as tailbone pain, is a persistent pain condition targeting the coccyx, a small triangular bone located at the lower end of the spine. The main cause of this pain is usually abnormal movement in the coccygeal region, which leads to continuous inflammation. Coccydynia more commonly affects women than men and is often associated with obesity. Although it most frequently occurs around the age of 40, it can be seen in individuals of all ages. The origins of coccydynia are varied, including both physical and psychological factors. The main physical causes are trauma from falling onto the buttocks, repetitive minor injuries, or childbirth, which are the most common triggers. Non-traumatic causes of coccydynia include degenerative diseases of the joints or discs, abnormal movements in the sacrococcygeal joint, obesity, infections, changes in the shape of the coccyx, or cancers in the pelvic or anorectal regions. The effectiveness of treatments for coccydynia varies considerably.
Several conservative treatment options exist for coccydynia, such as nonsteroidal anti-inflammatory drugs (NSAIDs), local analgesics, hot or cold applications, transcutaneous electrical nerve stimulation (TENS), specially designed wedge-shaped cushions (coccygeal cushions), and exercises aimed at relaxing the levator ani muscle. These methods aim to reduce pain and inflammation and improve the functionality of the coccyx and surrounding muscles. When these conservative approaches fail to provide relief, more invasive procedures may be considered. Techniques such as direct local anesthetic injections to the coccyx, coccygeal nerve blocks, caudal epidural injections, and ganglion impar blocks offer minimally invasive alternatives for coccydynia treatment. Among the methods for impar ganglion blocks, pulsed RF, thermocoagulation ablation techniques, and neurolytic techniques are considered treatments that provide long-term pain palliation. The transacrococcygeal technique for impar ganglion block is an easy and safe method. This technique allows neurolysis or radiofrequency thermocoagulation ablation of the impar ganglion and can be used for diagnostic blocks depending on the response to initial diagnostic injections.
The ganglion impar (Walther ganglion) is a single sympathetic ganglion formed by the convergence of the distal ends of the lumbosacral sympathetic chains. It is the lowest ganglion of the sympathetic nervous system. Being single and medial (unlike the paired paravertebral sympathetic ganglia), it is the only solitary sympathetic ganglion. It is located retroperitoneally, anterior to the sacrum, at the level of the sacrococcygeal symphysis, and posterior to the rectum. It provides sympathetic efferent fibers and receives afferent sensory information from many pelvic structures, supplying sympathetic and nociceptive innervation to the perineum, coccyx, anus, distal rectum, vulva, urethra, and vagina. Interventions on the ganglion impar disrupt afferent sympathetic and nociceptive pathways from the pelvis, perineum, and anal region. Interventions on the ganglion impar can be performed using various agents and techniques, including local anesthetics, corticosteroids, ethanol, phenol, botulinum toxin, radiofrequency ablation (RFA) or modulation (RFM), and cryoablation. The transsacrococcygeal technique is more commonly used. Numerous technique variations exist, but the goal is to successfully direct the needle to the anterior surface of the coccyx or sacrococcygeal symphysis to deliver local anesthetics, steroids, or neurolytic agents without damaging pelvic bones or organs. Radiopaque contrast is injected to visualize proper retroperitoneal distribution of the agent along the anterior surface of the coccyx.
Visceral pain mediated by sympathetic fibers in the perineal region can be effectively treated by neurolysis of the impar ganglion. Theoretically, this procedure can also be applied for pain due to malignancy, endometriosis, complex regional pain syndrome, prostate pain, radiation-induced enteritis, postherpetic neuralgia, and refractory coccydynia. The use of sympathetic chain ablation for persistent pain in the sacral-pelvic region differs from other targets, because the anatomical variation of the impar ganglion requires careful combination of radiofrequency thermocoagulation and neurolytic agents (alcohol or phenol) to maximize pain control. When using the thermocoagulation radiofrequency ablation technique, special equipment such as electrostimulation devices and minute controllers are required. Therefore, selective destruction of nerve fibers is possible, and the size and location of the lesion can be controlled, resulting in a lower risk of complications.
The effects of conventional radiofrequency (CRF) thermocoagulation for chronic coccydynia were retrospectively analyzed (patients unresponsive to conservative treatment and local injections for 6 months. Ten patients who responded to diagnostic block with 10 mL of 0.25% bupivacaine underwent CRF treatment. Approximately 90% of patients achieved successful results at 6 months, defined as a 50% reduction in VAS scores. Transcoccygeal/intercoccygeal CRF of the ganglion impar is simple, relatively safe, and should be considered for chronic coccydynia unresponsive to conservative therapy for 6 months. Similar findings were observed by another study in a retrospective analysis of CRF in 20 patients with chronic refractory coccydynia.
No previous study has compared the superiority of these two routinely applied long-term coccyx pain treatments.
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This study's planned enrollment of 90 is above the median of 60 across 1,941 interventional studies indexed under Back Pain.
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Radiofrequency ablation is performed on the ganglion impar using a 22G needle with a 10 mm active tip. Tissue impedance and motor/sensory responses are checked before ablation. Pulsed RFA is applied at 42 °C for 4 minutes. Pulsed RF treatments will be applied to patients only once, and pain, disability, sleep quality, and patient satisfaction will be assessed before treatment and at 1, 3, 6, and 12 months after the procedure
Procedure: Pulsed Radiofrequency
Conventional RF treatments will be applied to patients only once, and pain, disability, sleep quality, and patient satisfaction will be assessed before treatment and at 1, 3, 6, and 12 months after the procedure Radiofrequency ablation is performed on the ganglion impar using a 22G needle with a 10 mm active tip. Tissue impedance and motor/sensory responses are checked before ablation. Conventional RFA is applied for two cycles of 90 seconds at 80 °C.
Procedure: Conventional Radiofrequency
Once the needle is properly positioned along the sacrococcygeal disc line, 1 mL of radiopaque contrast is injected. The needle placement is confirmed in the lateral fluoroscopic view as a comma-shaped spread in the retroperitoneal space. Radiofrequency interventions on the ganglion impar are performed using a radiofrequency generator. A 22G radiofrequency needle (0.7×98.6 mm) with a 10 mm exposed active tip is used. Before performing the ablation, tissue impedance and motor and sensory responses (motor and sensory stimulation) are checked. The expected tissue impedance is \<500 ohms. Sensory paresthesia at \<1 V and 50 Hz is observed around the sacrococcygeal region. Pulsed RFA is applied at 42 °C for 4 minutes after stimulation.
Once the needle is properly positioned along the sacrococcygeal disc line, 1 mL of radiopaque contrast is injected. The needle placement is confirmed in the lateral fluoroscopic view as a comma-shaped spread in the retroperitoneal space. Radiofrequency interventions on the ganglion impar are performed using a radiofrequency generator. A 22G radiofrequency needle (0.7×98.6 mm) with a 10 mm exposed active tip is used. Before performing the ablation, tissue impedance and motor and sensory responses (motor and sensory stimulation) are checked. The expected tissue impedance is \<500 ohms. Sensory paresthesia at \<1 V and 50 Hz is observed around the sacrococcygeal region. Neuroablation is applied for 2 cycles of 90 seconds at 80 °C.
The Numeric Rating Scale (NRS)
Pain intensity was assessed using the Numeric Rating Scale (NRS), a linear pain scale ranging from 0 (no pain) to 10 (the worst imaginable pain)."
Time frame: From enrollment to the end of treatment at 12th months
Oswestry Disability Index (ODI)
Oswestry Disability Index (ODI): The ODI is a self-reported measure used to assess the extent to which a patient's daily activities are limited. It is one of the most commonly used tools in clinical research and routine patient follow-up to determine the level of functional disability. General Characteristics: The index consists of 10 sections, each scored from 0 to 5 (0: no difficulty, 5: maximum difficulty). The maximum raw score is 50, and the total score is multiplied by 2 to convert it to a percentage (0-100%). Assessment Categories (approximate): 0-20%: Minimal disability (the patient can continue daily activities and perform most tasks). 21-40%: Moderate disability. 41-60%: Severe disability (pain significantly affects daily life). 61-80%: Crippling disability (the patient is unable to perform many activities). 81-100%: Bed-bound or completely dependent, unable to maintain an active lifestyle.
Time frame: From enrollment to the end of treatment at 12th months
Pittsburgh Sleep Quality Index (PSQI)
Pittsburgh Sleep Quality Index (PSQI): The PSQI includes 18 items that contribute to its scoring. It assesses seven components: subjective sleep quality, sleep latency, sleep duration, habitual sleep efficiency, sleep disturbances, use of sleep medication, and daytime dysfunction. Some components are represented by a single item, while others are calculated by grouping several items. Each item is scored from 0 to 3, and the sum of the seven component scores forms the total PSQI score. The total score ranges from 0 to 21, with higher scores indicating poorer sleep quality. A total PSQI score of ≤5 indicates "good sleep quality," whereas a score \>5 indicates "poor sleep quality."
Time frame: From enrollment to the end of treatment at 12 months
Global Perceived Effect (GPE)
Global Perceived Effect (GPE): The GPE measures the patient's perception of their condition compared to a previous period. It reflects the response to the question: "How do you feel now compared to before treatment?" At 1, 3, 6, and 12 months after treatment, the patient's overall perceived effect will be assessed using a 7-point Likert scale: 1. \- Much worse 2. \- Worse 3. \- Slightly worse 4. \- No change 5. \- Slightly better 6. \- Better 7. \- Much better Patients reporting "much better" (score = 7) or "better" (score = 6) will be considered satisfied with the procedure.
Time frame: From enrollment to the end of treatment at 12th months
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Plan to share: No — Individual participant data will not be shared to ensure the confidentiality and privacy of the patients, in accordance with ethical approval and local regulations
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Adana City Training and Research Hospital