Redefining the coccygeal plexus

Neuromodulation Techniques in Chronic Refractory Coccydynia: A Narrative Review

Refractory coccydynia is a condition characterized by severe coccygeal pain and poses a challenging management dilemma for clinicians. Advancements in neuromodulation (NM) technology have provided benefits to people experiencing chronic pain that is resistant to standard treatments. This review aims to summarize the spectrum of current NM techniques employed in the treatment of refractory coccydynia along with their effectiveness. A review of studies in the scientific literature from 2012 to 2023 was conducted, revealing a limited number of case reports. Although the available evidence at this time suggests significant pain relief with the utilization of NM techniques, the limited scope and nature of the studies reviewed emphasize the need for large-scale, rigorous, high-level research in this domain in order to establish a comprehensive understanding of the role of NM and its effectiveness in the management of intractable coccydynia.

Novel approach for pericapsular radiofrequency ablation of sacrococcygeal junction for patients with coccydynia

Introduction

Coccydynia is a multifactorial complex clinical challenge. A multimodal approach with both conservative measures and procedural interventions is often recommended. We described a novel approach of radiofrequency (RF) ablation for the management of coccydynia.

Methods

Three patients with known history of coccydynia refractory to conservative therapy were referred to our clinic. All received different types of RF ablation before: one with anterior bipolar lesion with no analgesia benefit, one with posterior stripped lesion with good benefit but only after 8 weeks of pain flare and one received anterior monopolar lesion with 50% pain reduction for 2–3 months. All subjects underwent a novel RF ablation to the anterior surface of the sacrococcygeal and intercoccygeal joints with two bipolar lesions using multi-tined needles under fluoroscopy guidance. One bipolar lesion was between two needles: one in the sacrococcygeal and another in the intercoccygeal (between first and second coccyx) joints. Another bipolar lesion was between needles on both side of the sacrococcygeal joint.

Results

All experienced at least 65% pain relief for 6 months. The sitting endurance increased from less than 5 min to an average of 70 min. No adverse effect was observed in two and in the patient who used to have pain flare after lesioning, the pain flare lasted only for 2 weeks.

Discussion

The configuration of the two bipolar lesions with multi-tined needles in this case series stimulates the thinking of new approach for the ablation technique for pain from coccyx. Further prospective large case cohort study is needed.

Influence of psychiatric disorders and chronic pain on the surgical outcome in the patient with chronic coccydynia: a single institution's experience

OBJECTIVE

Performing coccygectomy procedures on patients with psychiatric disorders and/or chronic low back pain have been previously thought of as contributing factors leading to inconsistent and often poor results. To determine if these two variables affect the post-operative pain relief obtained after coccygectomy, an analysis of the opioid requirements and pain descriptions before and after surgery was undertaken in each patient studied.

METHODS

The hospital electronic medical records were searched, and only patients undergoing coccygectomy for chronic coccydynia were selected. A total of 8 patients were found. Each patient underwent a trial of conservative therapy prior to surgical evaluation.

RESULTS

The average duration of symptoms prior to surgery was 41.3 months. In 7 out of 8 patients, at least one psychiatric disorder was present. In 6 out of 8 patients, chronic low back pain was present. Pain control with opioid-based medicines was required in 5 out of 8 patients prior to surgery. Of those, 4 were able to discontinue or reduce the amount of opioid-based medicines consumed after surgery. The average follow-up was 9 months.

DISCUSSION

The results of this study indicate that patients with preexisting psychiatric disorders and/or chronic low back pain suffering from debilitating coccyx pain can obtain pain relief after coccygectomy as seen from a reduction in opioid requirements and pain burden. It should be noted that the obtained benefits from coccygectomy usually occur in a delayed fashion.

The Efficacy of Extracorporeal Shock Wave Therapy for Chronic Coccydynia

OBJECTIVE

Coccydynia is a disorder that decreases quality of life with significant functional failure. Extra-corporeal shock wave therapy (ESWT) is used to treat several painful musculoskeletal disorders.

SUBJECTS AND METHODS

The medical records of 34 patients (29 females, 5 males) who had been treated with ESWT between 2017 and 2018 for chronic coccydynia were evaluated. Visual analog scale (VAS) scores were noted at the initial consultation, at each session, and during the initial and follow-up (at 6 months) examinations after the treatment. The 36-item short form (SF-36) quality of life scale survey was conducted at the beginning and end of the treatment. MRI was performed before the start of the procedure and 1 month after the end of the treatment.

RESULTS

The mean VAS score was 9.6 (9-10) before the treatment and 3.4 (0-2) after the treatment (p < 0.05). The VAS score decreased to ≤3 in 79.4% of patients. Bone marrow edema regressed in 6% of patients. Significant improvement was observed in all of the SF-36 parameters, except for two.

CONCLUSION

In our patient group, ESWT provided effective pain control. In order to evaluate the efficacy of ESWT more accurately and sensitively, prospective randomized studies with longer follow-up periods, in which ESWT is compared with different energy doses and different treatment methods, are needed.

Radiofrequency Ablation in Coccydynia: A Case Series and Comprehensive, Evidence-Based Review

Objectives

Coccydynia is a condition with a multitude of different causes, characterized by ill-defined management. There are multiple prospective studies, including several controlled trials, that have evaluated conservative therapies. Additionally, a plethora of observational studies have assessed coccygectomy, but few studies have reported results for nonsurgical interventional procedures. In this report, we describe the treatment results of 12 patients who received conventional or pulsed radiofrequency for coccydynia and systematically review the literature on management.

Methods

We performed a retrospective data analysis evaluating patients who underwent pulsed or conventional radiofrequency treatment at Johns Hopkins Hospital and Walter Reed National Military Medical Center. A comprehensive literature review was also performed to contextualize these results.

Results

The mean age of patients treated was 50.25 years (SD = 11.20 years, range = 32-72 years), with the mean duration of symptoms being 3.6 years (SD = 3.36 years, range 1-10 years). There were 10 males and two females in this cohort. Among patients who received radiofrequency treatment, the average benefit was 55.5% pain relief (SD = 30.33%, range = 0-100%). Those who underwent conventional (vs pulsed radiofrequency) and who received prognostic blocks were more likely to experience a positive outcome. There were two cases of neuritis, which resolved spontaneously after several weeks.

Conclusions

Radiofrequency ablation of the sacrococcygeal nerves may serve as a useful treatment option for patients with coccydynia who have failed more conservative measures. Further research into this therapeutic approach and its benefit for coccydynia should incorporate a control group for comparison.

Comprehensive anatomical and immunohistochemical review of the innervation of the human spine and joints with application to an improved understanding of back pain

BACKGROUND

Pain of spinal origin contributes significantly to cervical, thoracic, and lower back pain presentations. Such pain originates in the nerve fibers supplying the joints or the surrounding ligaments and intervertebral discs. Although there has been little detailed discussion of spinal bony innervation patterns in the literature, the clinical implications of these patterns are anatomically and medically significant.

METHODS

The present review provides a detailed analysis of the innervation of the spine, identifying the unique features of each part via online search engines.

CONCLUSIONS

The clinical implications of these various studies lie in the importance of the innervation patterns for the mechanism of spinal pain. Immunohistochemical studies have provided further evidence regarding the nature of the innervation of the spine.

The anatomy of the sacrococcygeal cornual region and its clinical relevance

There has been no systematic study of the anatomy of the region between the sacral and coccygeal cornua. Reference texts describe an intercornual ligament connecting these structures. The aim of this study was to investigate the anatomy of this region, which may be relevant to unexplained cases of coccygeal pain (coccydynia) and local nerve blocks. The bony anatomy of the sacrococcygeal (SC) cornual region was analyzed in 33 CT scans obtained from supine adults of mostly European origin with no known SC pathology, 7 μCT scans of cadaver SC specimens, and 105 Asian Indian adult skeletons. A further five cadaver SC specimens were examined histologically. SC cornual fusion was seen in 45% of CT/μCT scans (mean age 67 years, 20 males) and in 20% of adult skeletons (78 males); there was no association with age or sex. In the absence of SC fusion, the mean intersacrococcygeal cornual gap was 7.1 ± 2.4 mm; this was bridged by an intercornual ligament composed of parallel vertical collagen fibers reinforced by elastin fibers on its anterior surface. Small nerve branches were observed adjacent to the ventral aspect of the intercornual ligament and, in one case, traversing the ligament. Ipsilateral sacral and coccygeal cornua are therefore normally bridged by an intercornual ligament that is probably innervated. The cornua are fused on one or both sides in 20-45% of adults. These findings may have implications for some cases of coccydynia and for anesthetists performing local nerve blocks.