Coccygodynia in a Long-Term Cancer Survivor Diagnosed with Metastatic Cancer: A Case Report.

Background and Objectives: Rectal cancer is considered cured if no recurrence is found during the 5-year follow-up period after treatment. After this period, patients often believe that the cancer is completely eradicated. However, in modern society, where lifespans have become longer, it is important to recognize that metastatic cancer may occur long after the initial treatment has concluded. This highlights the necessity of continued vigilance and the long-term follow-up of cancer survivors. Case report: We present a case of metastatic cancer of the coccyx in an 87-year-old female patient. This patient had undergone successful surgery and treatment for rectal cancer 10 years prior. She was considered cured after the standard 5-year follow-up period as she showed no signs of recurrence. The patient presented with simple coccygeal pain as the main complaint, without any other accompanying symptoms such as weight loss, fever, or changes in bowel habits, typically associated with cancer recurrence. During the clinical evaluation, irregularities in the bone cortex were detected while performing a nerve block using ultrasound. Given these findings, further diagnostic evaluations were performed. Advanced imaging techniques including MRI and CT scans led to a diagnosis of coccygeal metastasis. Conclusions: While the 5-year mark post-treatment is a significant milestone for rectal cancer patients, it does not guarantee the absolute eradication of the disease. Long-term monitoring and a thorough evaluation of new symptoms are essential for the early detection and management of late metastatic recurrences. This approach ensures that patients receive timely and appropriate care, potentially improving outcomes and quality of life.

Coccygeal tumours unveiled: a retrospective cohort analysis from a tertiary referral centre.

BACKGROUND: Isolated tumours affecting the coccyx are infrequent, with only a handful of documented cases in the literature. Herein, we highlight the most extensive consecutive case series involving various isolated coccyx tumours with varied clinical presentations and imaging features. METHODS: A retrospective search of our tertiary Orthopaedic oncology institute's oncology and Radiology database [Radiology Information System, Picture Archiving and Communication System, and Computerised Radiology Information System] for the keyword "Coccyx" and "Tumour" was performed over 15 years (between December 2007 and August 2022). Data collected was correlated with local histopathology and laboratory records. Patient demographics, clinical characteristics, and complementary imaging findings were recorded for analysis. RESULTS: One hundred and three lesions originating in the coccyx with a mean age of 62 years (range 25-90 years) were identified. There was a male preponderance with 59 male and 44 female patients (1.3:1.0). The most typical tumour noted was chordoma. Other lesions included a dermoid cyst, a myxopapillary ependymoma, a notochordal remnant, an osteochondroma, an Ewing sarcoma, and a teratoma. CONCLUSION: Our analysis suggests that most of the tumours involving coccyx are chordomas with a few rarely encountered benign and malignant tumours. Radiological imaging plays a vital role in characterising isolated tumours affecting the coccyx and guiding appropriate patient management. ADVANCES IN KNOWLEDGE: This is the largest reported series of coccygeal tumours. Chordoma is the commonest coccygeal tumour. Patients with unexplained coccydynia should undergo detailed investigations, preferably with cross-sectional imaging.

Iatrogenic rectal perforation after coccygeal radiofrequency ablation.

Coccygodynia (pain of the coccygeal bone) can be treated locally with anti-inflammatory drugs, local steroid injections, surgical removal of the coccyx and, more recently, with radiofrequency thermal ablation. Complications, such as perforation of the colon, can occur as a consequence of the close relationship between the rectum and the sacrococcyx and with the heat from the thermal ablation expanding to the surrounding tissue causing delayed damage with severe consequences. The treatment of this complication requires the combined effort of the gastrointestinal surgeon as well as a gastroenterologist. In this case report, we describe the treatment of this complication and the clinical course after a perforation of the rectum due to thermal ablation of the coccyx to treat long-standing coccygodynia.

Surgical management of a rare giant sacral meningocele in a child.

INTRODUCTION: Anterior sacral meningocele is a rare congenital disorder, occurring isolated or in syndromic disease. CASE REPORT: A 15-year-old patient who complained of abdominal pain and urinary dysfunction was managed surgically. Imaging diagnosed a giant presacral meningocele and agenesis of the coccyx. DISCUSSION: The presentation of sacral meningocele can be poorly symptomatic, which is why some patients are diagnosed late. Sometimes, diagnosis is suggested by non-specific abdominal symptoms or complications. Abdominal-pelvic radiological examination and lumbar spine MRI are essential, and treatment must be surgical. There are several surgical approaches, but currently no consensus. CONCLUSION: An unusual huge presacral cystic mass in a young patient may be isolated or part of a syndrome, and can be asymptomatic for a long time, leading to late diagnosis. The surgical approach should be based on multidisciplinary discussion. We operated on a giant anterior sacral meningocele in a child using a posterior approach, with a satisfactory result.

Mind the gap: paramedian approach for coccygectomy.

BACKGROUND CONTEXT: Coccydynia is pain in the coccyx that typically occurs idiopathically or from trauma. Most forms are self-limiting. However, if symptoms persist, nonsurgical treatment options can include offloading, NSAIDs, physical therapy, and steroid injections. If all treatment options fail, a growing body of evidence supports a coccygectomy for symptomatic relief. The standard approach for a coccygectomy involves a midline incision cephalad to the anus along the gluteal cleft. Historically, this method has had high rates of infection. PURPOSE: To improve healing and decrease infection rate, we propose the paramedian approach to a coccygectomy. This approach has the benefit of distancing the surgical site from the anus, diminishing the crevice effect of the incision, and increasing the dermal and subdermal thickness for improved surgical closure. STUDY DESIGN/SETTING: We present a case series study of 41 patients who underwent the paramedian approach coccygectomy using a 4 to 6 cm incision, approximately 0.5 to 1.5 cm lateral to the midline, for coccyx removal. These patients were evaluated postoperatively to determine infection rate and various outcome measures. PATIENT SAMPLE: Forty-one patients suffering from refractory coccydynia had a coccygectomy via the paramedian approach between 2011 and 2022 by the senior author. OUTCOME MEASURES: Outcome measures included self-reported measures (Oswestry Disability Index (ODI), Visual Analogue Scale (VAS) pain scale and satisfaction with procedure), physiologic measures (presence of infection and treatment provided) and functional measures (return to vocation/avocation). METHODS: Data was compiled and transferred to Microsoft Excel and analyzed. Two-tailed T-tests were used to compare the patient improvement in VAS and ODI as appropriate for statistical analysis. RESULTS: The patients' average age was 45.8 years. Patients' average body mass index was 27.9, with 71% of patients overweight or obese. A total of 68% of patients were female. Trauma was the most common precipitating factor (75.6%). Five patients presented with postoperative complications (12.1%), one requiring an incision and drainage, and four others were treated with antibiotics for wound erythema. Postoperative evaluations showed continual improvement, with the most significant improvement reported greater than 1-year postoperatively. The Visual Analogue Scale for pain dropped from 7.5 to 2.3 (p<.001), and the Oswestry Disability Index improved from 30.1 to 9.6 (p<.001). A total of 86.7% of patients reported either a good or excellent result. CONCLUSION: Coccygectomies via the midline approach have a variable infection rate, likely due to proximity of the incision to the anus and due to the crevice effect of the gluteal cleft in terms of aeration. These contributing factors are overcome in the paramedian approach, making it an effective option for treating refractory coccydynia that is nonresponsive to conservative management.

[Treatment options for coccygodynia]. / Therapieoptionen bei der Coccygodynie.

BACKGROUND: To this day, patients with coccyx problems are the most frequently underestimated patient population in orthopedic practices. The clinical picture of coccygodynia was first described in 1859. Nevertheless, discussions about the importance of coccyx problems remain a tiresome topic. All patients have in common that they have gone through a long ordeal with many therapists, examinations and therapeutic approaches without having received a real diagnosis. DIAGNOSTIC: The main symptom of coccygodynia is the pain directly on the lowest segment of the coccyx, which often only occurs when sitting and is intensified by the change in position, usually from a sitting to a standing position. Trauma can only be described as the trigger in 50% of cases. Women are four times more likely to be affected than men. The gold standard for imaging should be viewed from standing and seated dynamic lateral radiographs of the coccyx. TREATMENT: After the diagnosis has been made, conservative treatment should first be started with oral NSAIDs, relief with a coccyx cushion with a recess and, if necessary, physiotherapy to strengthen or loosen the pelvic floor. Local infiltrations with a glucocorticoid and local anesthetic directly in the painful area are also often promising. If the symptoms persist for more than 6 months, surgical treatment in the sense of removing the coccyx can be discussed with the patient. The literature shows a success rate of 80-90% if the indication was correct.

Minimally Invasive Open Reduction and Maintenance Technique for Anterior Sacrococcygeal Dislocation: A Case Report.

Anterior dislocation of the coccyx is rare, but it can occur due to trauma. Conservative treatment is usually performed. However, dislocation reduction may be required to control severe pain in the acute phase or to prevent chronic complications. If manual reduction fails, open reduction is required. The extent of the incision and the method used to maintain the reduction should be considered during open reduction. A 56-year-old male patient experienced a dislocation of the sacrococcygeal joint after falling backwards. Despite conservative treatment, the patient complained of persistent pain during sitting and when using the bathroom. A manual reduction was attempted but failed. We performed joystick reduction via minimal incision and maintained the reduction using a one-strand trans-osseous suture passing through the skin. The patient was advised to use a soft cushion when sitting or lying down for four weeks after surgery. The supine position was not restricted. The patient's symptoms significantly improved after surgery. At the 6-month follow-up, the sacrococcygeal joint showed good alignment and no surgical complications occurred. During the treatment of sacrococcygeal dislocation, the rapid alleviation of acute pain and minimizing potential complications are key points. If open reduction is needed, the minimally invasive reduction technique with a one-strand trans-osseous suture may offer patient satisfaction and a good surgical outcome.

Does primary tumor resection improve survival for patients with sarcomas of pelvic bones, sacrum, and coccyx who have metastasis at diagnosis ?

BACKGROUND: Recent studies demonstrated that primary tumor resection (PTR) improves survival of patients with metastatic bone sarcomas. However, it remains quite unclear regarding the role of PTR in the treatment of sarcomas of pelvic bones with synchronous metastasis at diagnosis. METHODS: Using the Surveillance, Epidemiology, and End Results Program, we enrolled a total of 385 patients with sarcomas of pelvic bones, sacrum, and coccyx who have metastasis at initial diagnosis, including 139 patients with osteosarcoma, 176 with Ewing sarcoma, and 70 with chondrosarcoma. Association between PTR and disease-specific survival (DSS) were investigated using the univariable and multivariable Cox regression models. Hazard ratio (HR) and 95% confidence interval (CI) were reported. Representative institutional PTR strategies and clinical outcomes for patients with metastatic pelvic sarcomas from our cancer center were displayed. RESULTS: The usage rate of PTR was 28.1% (39/139) in osteosarcoma, 13.6% (24/176) in Ewing sarcoma, and 41.4% (29/70) in chondrosarcoma with synchronous metastatic lesions. PTR was not associated with an improved DSS for metastatic pelvic osteosarcoma (HR = 0.686, 95% CI = 0.430 ~ 1.094, P = 0.113) and Ewing sarcoma (HR = 0.580, 95% CI = 0.291 ~ 1.154, P = 0.121). The use of PTR was associated with an improved DSS for metastatic pelvic chondrosarcoma (HR = 0.464, 95% CI = 0.225 ~ 0.954, P = 0.037). CONCLUSION: Primary lesion resection may provide a survival benefit for metastatic chondrosarcoma, but not for osteosarcoma and Ewing sarcoma of pelvic bones, sacrum, and coccyx. This population-based study recommends an active surgical intervention for metastatic chondrosarcoma while non-surgical treatment for metastatic osteosarcoma and Ewing sarcoma of the pelvis in terms of survival improvement.

Coccygeoplasty: preliminary experience with this new alternative treatment of refractory coccydynia in patients with coccyx hypermobility.

BACKGROUND: Coccydynia has many causes, including fracture, subluxation, and hypermobility of sacrococcygeal segments. Existing treatments are limited in their effectiveness. Coccygeoplasty (CP) is a relatively new, minimally invasive treatment that appears to address this difficult clinical challenge. OBJECTIVE: To describe clinical results at the time of the procedure and at 3- and 12-months' follow-up of patients with coccydynia related to subluxation and coccyx hypermobility treated with the CP technique. Additionally, to determine if there is any correlation between the final imaging and clinical results at 3- and 12-months' follow-up. METHODS: A prospectively maintained database was used, and all patients who underwent CP for chronic coccydynia between January 2005 and October 2018 were retrospectively reviewed. All the patients had painful hypermobility (greater than 25°) with anterior flexion confirmed on radiological imaging. Alternative causes of coccydynia were excluded using CT and MRI. Procedures were performed under local anesthesia with combined fluoroscopic and CT guidance. Clinical follow-up was performed at two time points: 3 and 12 months after treatment using the Visual Analogue Scale (VAS). RESULTS: Twelve patients were treated in a single center. No procedural complications occurred. At 3- and 12-months' follow-up, the majority (75%) of patients had significantly lower VAS scores than at baseline, with mean changes of 3.5 and 4.9, respectively. There was no pain recurrence at 12 months and just one patient had no improvement of the pain. Follow-up CT images confirmed fixation of the sacrococcygeal bone segments in nine patients; however, no correlation was found between final imaging results and clinical outcome (p=0.1). CONCLUSIONS: Patients with refractory painful coccyx subluxation and hypermobility undergoing CP have a favorable clinical response at 3- and 12-months' follow-up. Further studies are required to validate this technique and to identify predictors of treatment response. Coccygeoplasty may be considered a reasonable alternative to coccygectomy.

A retrospective study on the pathologies in patients with coccydynia-lumbosacralgia and their treatment.

BACKGROUND: The aim of this study was to arrange the treatment according to the etiology following the differential diagnosis in patients who had presented to the Orthopedics and Traumatology and General Surgery outpatient departments, and to emphasize the post-treatment success. METHOD: The charts of 156 patients who had presented to the Orthopedics and Traumatology, General Surgery Departments of the Kafkas University Faculty of Medicine between July 2012 and June 2021 were retrospectively reviewed after permission was obtained from the ethics committee in this study. The demographic findings and Visual Analogue Scale (VAS) results for those with a symptom of pain as detected during the physical examination were recorded from the patient charts. RESULTS: A total of 156 patients who had presented with traumatic and non-traumatic conditions to the Orthopedics Clinic complaining of pain, burning, sensitivity, discharge and hyperemia at the coccyx region were included in the study. The reason for the lumbosacralgia was found to be traumatic as in heavy lifting or working physically difficult jobs in 62 of the 95 patients (65.26%) who presented with lumbosacralgia and pain referred to the coccyx. The mean VAS was 7.37 before treatment and 2.32 following conservative treatment. There was a history of falling on the coccyx region in 8 of the 14 patients with traumatic isolated coccydynia. The pre-treatment mean VAS was 8.64 in the patients with a diagnosis of coccydynia while the post-treatment mean VAS was 0 in 8 patients with full recovery, 4.33 in 3 patients with partial recovery, and 9.66 in 3 patients with no recovery. The pre-treatment mean VAS was 7.58 in the 29 patients with thrombosed hemorrhoids, decreasing to 0 after treatment. The pre-treatment mean VAS was 4.16 in the 18 patients with a pilonidal sinus, again decreasing to 0 after treatment. CONCLUSION: Possible underlying etiological factors should be taken into account when making a diagnosis in patients with coccydynia and the treatment should be determined in a multidisciplinary manner.

Angiolipoma sacro. Reporte de un caso / Sacral angiolipoma. A case report

Fundamento: Los angiolipomas son tumores benignos que se presentan en adultos con una localización, preferentemente, en el espacio epidural posterior torácico. Objetivo: Presentar un caso que debutó con un traumatismo axial lumbosacro donde se evidenció una localización poco común de la lesión y sin relación con las estructuras del canal raquídeo. Presentación del caso: Hombre de 25 años que se cayó y debido a ello se le hizo un traumatismo directo en la región sacrococcígea con dolor y aumento de volumen regional, asociado a parestesias glúteas. Los estudios radiológicos evidenciaron una fractura del cóccix y la presencia de una lesión ubicada en las partes blandas, de aspecto redondeado, homogéneo, sólido, de poco más de 50 mm de diámetro. Se le realizó tratamiento quirúrgico que consistió en coccigectomía subperióstica y exéresis macroscópica de la masa. El estudio histológico concluyó el diagnóstico de un angiolipoma. Conclusiones: Los angiolipomas son tumores raros que tienen características radiológicas peculiares, requieren de alta sospecha clínico-imagenológica para indicar los estudios y el tratamiento. La exéresis total es recomendada para evitar la recurrencia y mejorar el pronóstico.

Background: Angiolipomas are benign tumors that appear in adults with special location in the posterior thoracic epidural position. Objective: To present a case that appeared with a lumbosacral axial trauma where a non-common lesion location was evidenced with no relation among the structures of the spinal canal. Case presentation: 25-year-old man who fell down, consequently suffered a painful direct trauma to the sacrococcygeal region and increased regional volume, associated with gluteal paresthesias. Radiological studies showed a fracture of the coccyx and presence of a lesion located in the soft tissues, with a rounded, homogeneous, solid aspect, a little more than 50 mm in diameter. Surgical treatment consisted of subperiosteal coccygectomy and macroscopic excision of the mass. Histological study concluded the diagnosis of an angiolipoma. Conclusions: Angiolipomas are rare tumors with peculiar radiological features, they require high clinical-imaging suspicion for studies and treatment. Total excision is recommended to avoid recurrence and improve prognosis.

[Coccygodynia: Case Reports and Literature]. / Coccygodynie: vlastní kazuistiky a prehled literatury.

Coccygodynia, or tailbone pain, is the most common in women after trauma (complicated childbirth, fall). This pain can be treated conservatively (by using analgesics, local injections, physiotherapy) or by surgical coccygectomy. In the presented article, a set of five female patients is evaluated, in whom, after the failing conservative therapy, coccygectomy was indicated for persistent coccygodynia. In all female patients, improvement of their clinical condition and alleviation of pain were reported. Coccygectomy has its place in the management of coccygodynia and in correctly chosen patients significant pain reduction can be expected. Key words: coccygodynia, coccyx, coccygectomy, trauma.

Plasma profile of follicle-stimulating hormone and sex steroid hormones after a single epidural administration of follicle-stimulating hormone via caudal vertebrae in Holstein dry cows.

The conventional follicle-stimulating hormone (FSH) treatment for bovine superstimulation involves multiple intramuscular injections, which is stressful for animals and onerous. We herein investigated whether a single epidural injection of porcine FSH (pFSH) can induce superovulation and peripheral concentrations of pFSH and steroid hormones after the treatment in Holstein dry cows. We intramuscularly administered pFSH twice daily to three cows for 3 days (control) or a single epidural pFSH administration (epidural). Numbers of follicles (≥10 mm in diameter) at estrus and corpora lutea at luteal phase were counted by ultrasonography. Blood was sampled from 0 to 104 h after the first pFSH administration and plasma pFSH, progesterone, androstenedione, testosterone, and estradiol-17ß concentrations were measured. Numbers of follicles (control: 18.3 ± 7.5, epidural: 15.7 ± 4.0; mean ± SD) and corpora lutea (control: 7.3 ± 4.2, epidural: 8.0 ± 2.6) were similar between both treatments. Plasma pFSH concentrations were higher in epidural than in control (p < 0.01). Although no significant differences were observed in progesterone, androstenedione, or estradiol-17ß concentrations between the groups, testosterone concentrations were slightly lower with the epidural treatment than with the control treatment (p = 0.08). In conclusion, superovulation was induced by a single epidural injection of pFSH, which achieved higher pFSH level than the multiple injections in Holstein dry cows.

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.

Coccygectomy in the Treatment of Chronic Coccydynia.

STUDY DESIGN: This is a retrospective cohort study. OBJECTIVE: The aim of this article was to evaluate the results of patients operated for chronic coccydynia, and determine any factors that could affect outcomes. SUMMARY OF BACKGROUND DATA: Patients with coccydynia who do not respond to conservative treatment will often profit from coccygectomy. Studies of results and complications vary considerably and often report on a limited number of patients. Methods. A total of 184 patients were operated with coccygectomy in our department and followed-up with questionnaires after a minimum of 1 year post-operatively. Treatment results were compared to their preoperative state, and any complications or reoperations were recorded and analyzed. Results. A total of 171 patients (93%) responded to final follow-up. The overall success rate was 71%, defined by patients being either completely well or much better at final follow-up. Furthermore, 89% off all patients would have consented to the operation if they had known the outcome in advance. The rate of post-operative infections was reduced from 10% to 2% by increasing the duration of prophylactic postoperative antibiotics from 24 to 48 hours (P = 0.018). CONCLUSION: Coccygectomy, for patients where conservative measures have failed, seems to give acceptable levels of success and high levels of patient satisfaction. The main complication after this procedure is infection, and the risk can be somewhat reduced by using antibiotic prophylaxis for 48 hours after surgery. LEVEL OF EVIDENCE: 4.

A novel radiological classification for displaced os coccyx: the Benditz-König classification.

BACKGROUND: Treatment of coccygodynia is still a challenging entity. Clear surgical selection criteria are still lacking. The aim of the investigation was to establish a novel radiological classification for surgical decision-making in coccygodynia cases. MATERIAL AND METHODS: Retrospective analysis of standing and sitting X-rays of coccygodynia patients referred to a single centre from 2018 to 2020. The sacro-coccygeal angle (SCA), the intra-coccygeal angle (ICA) and the difference of the intervertebral disc height (∆IDH) were measured. All coccyges were distributed in subtypes and correlated with the patients' treatment. RESULTS: In total, 138 patients (female/male: 103/35) with a mean age of 45.6 ± 15.4 years were included in the study. In total, 49 patients underwent coccygectomy. Four different subtypes of displaced coccyges were identified: Type I with a non-segmented coccyx, anterior pivot, increased SCA and ICA from standing to sitting, ∆IDH = 1.0 ± 1.5 mm. Type II with a multisegmented coccyx, anterior pivot, increased SCA and ICA standing/sitting, ∆IDH = 1.1 ± 1.6 mm. Type III showed a posterior pivoted coccyx, negative SCA and ICA, ∆IDH = 0.6 ± 1.6 mm. Type IV is characterized by an anterior-posterior dissociation of the tail bone with a positive SCA, and the ICA shifted from a posterior to an anterior orientation. ∆IDH was - 0.6 ± 1.8 mm. CONCLUSION: The presented radiological classification could help to facilitate the surgical decision-making for patients with displaced os coccyx. In addition, lateral and sitting X-rays were easy to perform and did not need unnecessary ionizing radiation like in CT scans and were more cost-effective than MRI investigations. The subtypes III and especially IV were more likely leading to surgery.

The interdisciplinary management of coccydynia: A narrative review.

Pain that develops in the coccyx or surrounding tissues is known as coccydynia, which occurs as a result of many etiologies both traumatic and nontraumatic. Although coccydynia most commonly affects middle-aged women, it may be found in both sexes and in all age groups. The aim of this article is to provide an overview of the presentation, diagnostic imaging, and pathophysiology of coccydynia, and to comprehensively review the current treatment options. A review of publications from 1990 to 2020 using search words related to the treatment of coccydynia in PubMed and Google Scholar was completed. Level II evidence was found supporting stretching, manipulation, and extracorporeal shock wave therapy. There are no data from high-quality studies to support injection-based therapy including corticosteroids, prolotherapy, nerve blocks, and radiofrequency ablation, although there are small retrospective and prospective observational studies suggesting benefit. Level III evidence was found supporting coccygectomy for chronic/refractory coccydynia. There are no data from randomized controlled trials to support the use of neuromodulation (sacral burst and dorsal root ganglion stimulation), although there are case reports suggesting benefit. High-level, comparative studies are lacking to guide the treatment of coccydynia and should be a focus for future research studies.

Anococcygeal Nerve and Sitting Pain: Differential Diagnosis and Treatment Results.

BACKGROUND: The plastic surgeon is often asked to reconstruct the sacral area related to pilonidal cysts or a tumor, or after other surgery, such as coccygectomy. When sitting pain is not due to the pudendal or posterior femoral cutaneous nerve injury, the anococcygeal nerve (ACN) must be considered. Clinically, its anatomy is not well known. Rather than consider coccygectomy when the traditional nonoperative treatment of coccydynia fails, resection of the ACN might be considered. METHODS: A review of traditional anatomy textbooks was used to establish classical thoughts about the ACN. A retrospective cohort of patients with sitting pain related to the coccyx was examined, and those operated on, by resecting the ACN, were examined for clinicopathologic correlations. RESULTS: When the ACN is described in anatomy textbooks, it is with varying distributions of innervated skin territory and nerve root composition. Most include an origin from sacral 5 and coccygeal 1 ventral roots. Most agree that the ACN forms on the ventral side of the sacrum/coccyx, alongside the coccygeus muscle, to emerge laterally and travel dorsally to innervate skin over the coccyx and lower sacrum. A review of 13 patients with sitting pain due to the ACN, from 2015 to 2019, demonstrated a mean age of 54.6 years. Eleven were female. The etiologies of ACN injury were falls (9), exercise (3), and complication from surgery (1). Six of the 9 patients who had surgery were able to be followed up with a mean length of 36.3 months (range, 11-63 months). Overall, 3 had an excellent result, 2 had a good result, and 1 was not improved. The one with a failed result showed improvement with coccygectomy. CONCLUSIONS: The ACN must be included in the differential diagnosis of sitting pain. It is most often injured by a fall. The ACN can be evaluated with a diagnostic nerve block, can be identified at surgery, and can be resected, and its proximal end can be implanted into the coccygeus muscle. This surgery may prove an alternative to coccygectomy.