Sacrococcygeal Joint Research Articles

Authors’ reply to the letter to the editor of P.M. Foye et al. concerning “CT Morphology and Morphometry of the normal adult coccyx” by Woon JT et al. (2013); Eur Spine J 22(4):863–870

We thank the correspondents for their kind comments about our recently published study [1]. We agree with their statement that certain bony features present in normal adults could nevertheless be a potential source of pain in some patients with coccydynia. Indeed, this prompted us to complete a further study comparing the bony morphology of the coccyx in normal adults with that in patients with coccydynia, which we have recently published [2]. In this study, women with coccydynia were found to have a significantly higher frequency of bony spicule formation than normal women (44 vs. 19 %; P < 0.01). Affected women also had a significantly more ventrally curved coccyx and a lower prevalence of sacrococcygeal joint fusion. These data will hopefully provide a better understanding of the static bony changes present on cross-sectional imaging in patients with coccydynia.

Magnetic Resonance Imaging Morphology and Morphometry of the Coccyx in Coccydynia

Retrospective case-control study. To determine if differences exists between the bony anatomy of the coccyx in patients with coccydynia and that in subjects with no known coccygeal pathology. Numerous bony characteristics of the coccyx have been described in patients with coccydynia but their significance is uncertain. This study aimed to evaluate these in patients with coccydynia and compare them with normal coccyges. Magnetic resonance scans of the coccyx from 107 adults (mean age, 43 ± 12 yr; 84 females) with clinically diagnosed coccydynia were retrospectively analyzed and compared with 112 computed tomographic scans from sex-matched adults with normal coccyges. The following were assessed: coccygeal segmentation; sacrococcygeal and intercoccygeal joint fusion, angles, and curvature; bony spicule formation; and subluxation. Compared with normal, females with coccydynia had a more ventrally curved coccyx (curvature index, 85 ± 7 vs. 90 ± 5; P< 0.01), a lower prevalence of sacrococcygeal joint fusion (27% vs. 58%, P< 0.01), and a higher frequency of bony spicule formation (44% vs. 19%, P< 0.01). Males with coccydynia showed a trend toward a more ventrally curved coccyx (curvature index: 86 ± 6 vs. 89 ± 5, P< 0.08), and a lower prevalence of sacrococcygeal (27% vs. 60%, P< 0.02) and intercoccygeal (0% vs. 22%, P< 0.02) joint fusion. Combining statistically significant coccygeal parameters in a logistic regression model yielded sensitivity, specificity, and positive predictive values of 72%, 71%, and 73%, respectively in females and 52%, 92%, and 73%, respectively in males. This is the most detailed comparison of coccygeal morphology and morphometry in adults with and without coccydynia investigated using cross-sectional imaging. Anatomical differences in joint fusion and coccygeal curvature may either predispose to the development of coccydynia or arise as a result of this condition.

Developmental mechanism of juvenile coccygeal fibrosis (so‐called coccygeal pad)

Coccygeal pad is a nodular lesion in the sacrococcygeal area, typically involving a proliferation of collagen bundles. The etiology and optimal treatment remain unclear. We investigated the etiology using a systematic review of the available published work, two cases that we examined and treated, and measurements of body pressure in a sitting position in seven healthy volunteers. Forty-two cases (34 male, eight female) from the published work were analyzed in terms of age at presentation and onset, clinical appearance, radiological findings, histopathological findings, treatment and etiology. Mean age at presentation was 18.6 years. The suspected age at onset in 30 cases (75%) ranged from elementary school to high school age. In terms of radiological findings, anterior dislocation of the coccyx was found in 79.5%. In terms of histopathological findings, marked thickening of the dermis due to the proliferation of collagen bundles was observed in all examined cases. No nodule recurrence was found after resection, even without surgical treatment of coccygeal bone prominence. Chronic stimulation on a sharply angulated sacrococcygeal joint was considered an etiologic factor in 79.4%. High pressure in the sacrococcygeal region in a relaxed sitting position on a hard school chair was shown in one of our cases and healthy children. This nodular lesion appears to represent a fibrous lesion related to chronic stimulation at school age. We propose a new name for this nodule, "juvenile coccygeal fibrosis", based on the pathological presentation and age predilection.

EOS Imaging of the Human Pelvis: Reliability, Validity, and Controlled Comparison with Radiography

The EOS technique represents a unique imaging modality combining low radiation exposure with high image quality. As its applications for pelvic imaging may increase with time, we performed a pilot study to evaluate the validity and reliability of this technique for the assessment of gross pelvic and acetabular morphology. Consecutive conventional and EOS radiographs of a human cadaveric pelvis were made in 5° intervals of sagittal tilt and axial rotation (range, -15° to 15° for each). Six measurements were made on each image: (1) the vertical distance between the sacrococcygeal joint and the upper border of the pubic symphysis, (2) the horizontal distance between the midpoints of these structures, (3) the distance between the anterior superior iliac spines, (4) the distance between the facets of S1, (5) the Sharp angle, and (6) the Tönnis angle. Coxa profunda and crossover signs were also evaluated. The findings of the two imaging techniques were correlated with each other and with true linear measurements made on the cadaveric pelvis. All measurements were performed by two independent observers, and one observer repeated all measurements to assess reproducibility. Both observers were blinded to the true linear measurements made on the pelvis. There was a strong correlation between the results of the conventional and EOS radiography (Pearson correlation coefficient, 0.644 to 0.998), and both modalities had high intraobserver and interobserver reproducibility (intraclass correlation coefficient, 0.795 to 1.000). Intraobserver and interobserver agreement on the presence of coxa profunda were both 100%. Intraobserver agreement (96.2%) and interobserver agreement (92.3%) on the presence of the crossover sign were marginally lower. Linear measurements differed significantly between the two modalities because of distortion caused by magnification effects in the conventional radiographic imaging (p &lt; 0.05). The EOS imaging technique proved reliable for the assessment of gross pelvic and acetabular morphology, and it may be an alternative to current radiography for primary imaging in the pediatric population and potentially in adults as well. This study did not evaluate the ability of EOS imaging to detect subtle radiographic anatomic abnormalities.

Chronic female pelvic pain

Chronic pelvic pain (CPP) is defined as nonmalignant pain perceived in the structures related to the pelvis that has been present for more than 6 months or a non acute pain mechanism of shorter duration. Pain in the pelvic region can arise from musculoskeletal, gynaecological, urologic, gastrointestinal and or neurologic conditions. Key gynaecological conditions that contribute to CPP include pelvic inflammatory disease (PID), endometriosis, adnexa pathologies (ovarian cysts, ovarian remnant syndrome), uterine pathologies (leiomyoma, adenomyosis) and pelvic girdle pain associated with pregnancy. Several major and minor sexually transmitted diseases (STD) can cause pelvic and vulvar pain. A common painful condition of the urinary system is Interstitial cystitis(IC. A second urologic condition that can lead to development of CPP is urethral syndrome. Irritable bowel syndrome (IBS) is associated with dysmenorrhoea in 60% of cases. Other bowel conditions contributing to pelvic pain include diverticular disease,Crohn's disease ulcerative colitis and chronic appendicitis. Musculoskeletal pathologies that can cause pelvic pain include sacroiliac joint (SIJ) dysfunction, symphysis pubis and sacro-coccygeal joint dysfunction, coccyx injury or malposition and neuropathic structures in the lower thoracic, lumbar and sacral plexus. Prolonged pelvic girdle pain, lasting more than 6 months postpartum is estimated in 3% to 30% of women. Nerve irritation or entrapment as a cause of pelvic pain can be related to injury of the upper lumbar segments giving rise to irritation of the sensory nerves to the ventral trunk or from direct trauma from abdominal incisions or retractors used during abdominal surgical procedures. Afflictions of the iliohypogastric, ilioinguinal, genitofemoral, pudendal and obturator nerves are of greatest concern in patients with pelvic pain. Patient education about the disease and treatment involved is paramount. A knowledge of the differential diagnosis of the pain generators leads to a diagnosis specific management of the pain condition. Using a multidisciplinary approach can improve outcomes for patients suffering from the condition and minimize the associated disability.

Resection of large sacral tumors: a report of 4 cases.

Tumors of the sacrum and related neurological and pelvic structures are rare pathologic conditions.Sacral tumors are a diagnostic challenge because patients often present with nonspecific complaints such as low back pain, sacrococcygeal joint pain, referred lag and buttock pain. Because of diagnostic and radiographic challenges, the detection of sacral mass can be delayed which complicates any prospect surgical intervention as tumors can be quite large at the time of treatment. Furthermore, the complex local anatomy of the sacrum and presence of numerous other structures make the resection procedure even more sophisticated and necessitate adoption of a multidisciplinary approach towards the treatment. The present study discuses the diagnosis, treatment and complication of 4 cases with large sacral mass.

Atlas of Ultrasound-guided Procedures in Interventional Pain Management

Atlas of Ultrasound-guided Procedures in Interventional Pain Management

Blockade of the Ganglion Impar (Walther), Using Ultrasound and a Loss of Resistance Technique

The ganglion impar is an unpaired sympathetic structure located at the level of the sacrococcygeal joint. Blockade of this structure has been utilised to treat chronic perineal pain. Methods to achieve this block often involve the use of fluoroscopy which is associated with radiation exposure of staff involved in providing these procedures. We report a combined loss of resistance injection technique in association with ultrasound guidance to achieve the block. Ultrasound was used to identify the sacrococcygeal joint and a needle was shown to enter this region. Loss of resistance was then used to demonstrate that the needle tip lies in a presacral space. The implication being that any injectate would be located in an adequate position. The potential exception would be a neurodestructive procedure as radiographic control of needle tip in relation to the rectum should be performed and recorded. However when aiming for a diagnostic or local anaesthetic based treatment option we feel that this may become an accepted method.

Perineal and Pelvic Anatomy of Extralevator Abdominoperineal Excision for Rectal Cancer: Cadaveric Dissection

Circumferential margin positivity and tumor perforations are the main reasons for the poor oncological outcome following standard abdominoperineal excision for low rectal cancer. The extralevator abdominoperineal excision approach has been developed to avoid "coning down" or "surgical waisting"; however, surgical education in this area has been neglected. This study aims to define correct surgical anatomical planes for extralevator abdominoperineal excision and show the differences in excision planes between standard and extralevator abdominoperineal excision. Macroscopic surgical dissections were performed in a clinical anatomy laboratory. The dissections were recorded as video clips. In accordance with the surgical technique of extralevator abdominoperineal excision, abdominal and then perineal dissections were performed on 1 female and 5 male cadavers. Neurovascular, muscular, and fascial structures located in or near the excision field were carefully revealed. The surgical planes of extralevator abdominoperineal excision, which widen the tumor-free margins and prevent inadvertent bowel perforation, are described in this step-by-step anatomical dissection study. Within the surgical excision planes, sacral vessels and sympathetic chains form a neurovascular network at the level of the sacrococcygeal joint. Although pelvic autonomic plexuses were away from the lateral incision line, their branches extending to urogenital organs were very close to the anterolateral dissection line. Perineal dissection showed that the internal pudendal vessels and pudendal nerve were close to the lateral excision plane. The superficial transverse perineal muscle and perineal body were the most important landmarks to determine the anterior boundary of dissection. The study focused on the perineal dissection of extralevator abdominoperineal excision. Successful extralevator abdominoperineal excision crucially depends on an accurate knowledge of surgical anatomical planes.

Comparison of two methods for measuring the pubococcygeal line from sagittal-plane magnetic resonance imaging

The pubococcygeal line (PCL) is an important reference line for determining measures of pelvic organ support on sagittal-plane magnetic resonance imaging (MRI); however, there is no consensus on where to place the posterior point of the PCL. As coccyx movement produced during pelvic floor muscle (PFM) contractions may affect other measures, optimal placement of the posterior point is important. This study compared two methods for measuring the PCL, with different posterior points, on T2-weighted sagittal MRI to determine the effect of coccygeal movement on measures of pelvic organ support in older women. MRI of the pelvis was performed in the midsagittal plane, at rest and during PFM contractions, on 47 community-dwelling women 60 and over. The first PCL was measured to the tip of the coccyx (PCLtip) and the second to the sacrococcygeal joint (PCLjnt). Four measures of pelvic organ support were made using each PCL as the reference line: urethrovesical junction height, uterovaginal junction height, M-line and levator plate angle. During the PFM contraction the PCLtip shortened and lifted (P < 0.001); the PCLjnt did not change (P > 0.05). The changes in the four measures of pelvic organ support were smaller when measured relative to the PCLtip as compared to those to the PCLjnt (P < 0.001). Coccyx movement affected the length and position of the PCLtip, which resulted in underestimates of the pelvic-organ lift produced by the PFM contraction. Therefore, we recommend that the PCL be measured to the sacrococcygeal joint and not to the tip of the coccyx.

Application of ganglion impar block in patient with coccyx dislocation

Sacrococcygeal dislocation is a rare injury. The ganglion impar (also called the ganglion of Walther) is a single, small solitary, sympathetic ganglion located in the retrorectal space, anterior to the sacrococcygeal joint or coccyx. It provides the nociceptive and sympathetic supply to the perineal structure. Ganglion impar blockade is not a routinely used anesthetic and analgesic procedure in clinical practice. An elective intrarectal manuel treatment was planned for a woman patient with coccyx dislocation due to falling down from a chair 5 days ago. Ganglion impar block was performed with saccrococcygeal approach using 22 gauge spinal needle along with fluoroscopy following routine monitorization. Blood pressure, heart rate, peripheral oxygen saturation and visual analog scale (VAS) were recorded before and, after block with three minute intervals. VAS value of the patient, 8 before the procedure, decreased 50% 6 minutes after block. Intrarectal manuel treatment was applied to the patient with VAS of 0 at 9th minute. Hemodynamic values were within normal limits during and after the procedure and no motor block was observed. The patient with VAS of 0 at 2nd and 6th hour after block was discharged. VAS of 0 was determined at 24th and 48th hour by phone call. In conclusion, ganglion impar block provided adequate analgesia without causing any complications during and after the intrarectal manuel treatment for the patient with coccyx dislocation. However, we believe that further clinical studies are required to establish the safety and efficiency of this technique for other procedures at perianal region.

Ultrasound-Guided Ganglion Impar Block: A Technical Report

Ganglion impar block is an uncommon procedure that has been performed traditional with fluoroscopy. One approach is the trans-sacrococcygeal approach. Sometimes this can be difficult because the sacrococcygeal joint (SCJ) cannot be readily seen on anteroposterior (AP) and lateral fluoroscopy. This technical report describes the feasibility of ultrasound in assisting ganglion impar blocks. We performed ganglion impar block using ultrasound as the primary imaging tool, with fluoroscopic confirmation in 15 patients. We used a linear array transducer (5-12 MHz) to obtain sonographic transverse and longitudinal views at the sacral cornua; we identified the first cleft below the sacral hiatus as the SCJ. Then we inserted a 23-gauge (7 cm in length) needle into the SCJ under sonographic guidance. Then we confirmed proper needle depth by lateral fluoroscopy and injection of contrast agent. In all 15 procedures, we accurately located and passed the needle into the patients' SCJs under real time sonographic guidance. In cases where the cleft cannot be readily seen on AP and lateral fluoroscopy, we have found ultrasound to be of assistance. Ultrasound does not replace fluoroscopy, because lateral fluoroscopy is still required to establish safe depth, and correct site of injection. However, ultrasound can be helpful when fluoroscopy alone is insufficient.

Paracoccygeal Corkscrew Approach to Ganglion Impar Injections for Tailbone Pain

A new technique for performing nerve blocks of the ganglion impar (ganglion Walther) is presented. These injections have been reported to relieve coccydynia (tailbone pain), as well as other malignant and nonmalignant pelvic pain syndromes. A variety of techniques have been previously described for blocking this sympathetic nerve ganglion, which is located in the retrorectal space just anterior to the upper coccygeal segments. Prior techniques have included approaches through the anococcygeal ligament, through the sacrococcygeal joint, and through intracoccygeal joint spaces. This article presents a new, paracoccygeal approach whereby the needle is inserted alongside the coccyx and the needle is guided through three discrete steps with a rotating or corkscrew trajectory. Compared with some of the previously published techniques, this paracoccygeal corkscrew approach has multiple potential benefits, including ease of fluoroscopic guidance using the lateral view, ability to easily use a stylet for the spinal needle, and use of a shorter, thinner needle. While no single technique works best for all patients and each technique has potential advantages and disadvantages, this new technique adds to the available options.

Coccygectomy For Coccydynia: Case Series and Review of Literature

This is a case series in which case notes review and telephone interview update were used to assess the outcome following coccygectomy. To correlate the clinical results of coccygectomy with histology and discography of the sacrococcygeal and intercoccygeal segments. Clinicians regard chronic disabling pain in the sacrococcygeal region with much dismay because of the reputed unpredictability of the treatment outcome. A total of 38 patients had coccygectomy for intractable coccydynia, and 31 were available for follow-up. The excised specimen with intact sacrococcygeal joint was sent for histologic examination in 22 patients. There were 6 patients investigated using sacrococcygeal and intercoccygeal discography. Mean postoperative follow-up was 6.75 years (range 2-16). There were 16 patients who benefited highly from the surgery, and 6 benefited to some extent, giving an overall beneficial result of 71%. Of all specimens, 86.3% had histologic changes of degeneration. Moderate-to-severe degenerate changes in sacrococcygeal and intercoccygeal joints on histology were found in 54.5% of patients. Of these patients, 83.3% did well with surgery. Only 57.1% of those patients with mild changes did well. There were 2 patients who had positive discography, and both did well with surgery. Three patients had negative diskographies, and 2 of them had a poor result, and 1 had only some relief. It is possible that degenerate changes in sacrococcygeal discs and/or intercoccygeal discs are associated with pain. Surgical results are better in those with a severe degree of degenerative change. Coccygectomy remains a successful treatment for a majority of severely disabled patients with coccydynia.

Noninvasive sacral chordoma presenting as a benign soft tissue mass

In this case report, we describe a sacral chordoma, which had an atypical presentation as a mobile, encapsulated, benign soft tissue mass. The patient was asymptomatic, except for the slight enlargement of this lesion. Biopsy of this mass showed a lobulated tumor with bland neoplastic cells in a rich myxoid matrix with the classical immunohistochemical profile of chordoma. Opposite to this classical histological picture of chordoma, the imaging studies (computed tomography and magnetic resonance imaging) could not find any sacral involvement or lytic destruction. Surgical excision of this chordoma confirmed all preoperative findings and diagnoses, showing an encapsulated mass in the sacral soft tissue that has not invaded into the sacrum. This chordoma originated from the sacrococcygeal joint and grew parallel to the sacrum and below the skin. At the same time, histological sections and immunostains reconfirmed diagnosis of chordoma.

Estimation of pelvic tilt on anteroposterior X-rays—a comparison of six parameters

To compare six different parameters described in literature for estimation of pelvic tilt on an anteroposterior pelvic radiograph and to create a simple nomogram for tilt correction of prosthetic cup version in total hip arthroplasty. Simultaneous anteroposterior and lateral pelvic radiographs are taken routinely in our institution and were analyzed prospectively. The different parameters (including three distances and three ratios) were measured and compared to the actual pelvic tilt on the lateral radiograph using simple linear regression analysis. One hundred and four consecutive patients (41 men, 63 women with a mean age of 31.7 years, SD 9.2 years, range 15.7-59.1 years) were studied. The strongest correlation between pelvic tilt and one of the six parameters for both men and women was the distance between the upper border of the symphysis and the sacrococcygeal joint. The correlation coefficient was 0.68 for men (P<0.001) and 0.61 for women (P<0.001). Based on this linear correlation, a nomogram was created that enables fast, tilt-corrected cup version measurements in clinical routine use. This simple method for correcting variations in pelvic tilt on plain radiographs can potentially improve the radiologist's ability to diagnose and interpret malformations of the acetabulum (particularly acetabular retroversion and excessive acetabular overcoverage) and post-operative orientation of the prosthetic acetabulum.

Tilt and Rotation Correction of Acetabular Version on Pelvic Radiographs

Anteroposterior pelvic radiographs are the gold standard of imaging for mechanical hip problems. However, correct interpretation is difficult because the projected morphologic features of the acetabulum and nearly all routinely used hip parameters depend on individual pelvic position, which can vary considerably during acquisition. We developed software that recreates the projected acetabular rim and the measured hip parameters as if obtained in a standardized orientation. The vertical and horizontal distances between two easy identifiable points were used as indicators of tilt and rotation. These points were the middle of the sacrococcygeal joint and the middle of the upper border of the symphyseal gap. Calibration of the indicators was achieved by means of serial pelvic radiographs of 20 cadaver pelves. Validation of tilt indicator in 100 patients and a theoretical error analysis revealed that for accurate tilt prediction an additional one-time lateral radiograph of the pelvis is mandatory. The computer-assisted method allows standardized evaluation of anatomic morphologic differences of femoral coverage (dysplasia, retroversion), making their clinical relevance for development of early osteoarthritis more valuable.

Dorsal Transsacrococcygeal Rectal Approach

A modification of the dorsal rectal approach is described as an alternative to consider in selected low and middle rectal lesions unsuitable for the transanal approach. The dorsal rectal approach is performed through the sacrococcygeal joint and below the gluteus maximus muscle resulting in an easier, safe, and well-tolerated procedure.

Thermocoagulation of the Ganglion Impar or Ganglion of Walther: Description of a Modified Approach. Preliminary Results in Chronic, Nononcological Pain

The ganglion impar, a single structure usually found at the anterior aspect of the sacrococcygeal joint, is the lowest ganglion of the paravertebral sympathetic chain. Its blockade is indicated in visceral pain syndromes and/or sympathetic pain syndromes of the perineal region. Several approaches to this block have been described, mainly through the anococcygeal or sacrococcygeal ligaments. We propose a modified approach to thermocoagulation of the ganglion impar, using a two-needle technique, the first one, placed through the sacrococcygeal ligament, the transsacrococcygeal needle, and the second one through a coccygeal disc, the transdiscal needle. The thermocoagulation technique that we employ uses a conventional radiofrequency application of 80 degrees C for 80 seconds through each needle. In this prospective study, 13 patients with chronic perineal, noncancer-related pain were followed for a maximum of 6 months. All of these patients underwent diagnostic ganglion impar block with local anesthetic prior to inducing neurodestruction with conventional radiofrequency application, as a positive result to the diagnostic local anesthetic block was a requisite for radiofrequency neurodestruction. We measured pain using a visual analog scale (VAS) before and after treatment. Statistical significance was assessed using the Mann-Whitney U-test and Wilcoxon range summation test. Initially the VAS was equal to or greater than 7. After therapy the VAS decreased by an average of 50% in the whole group. There were no adverse events. Our result show that this proposed modified approach to the block and use of radiofrequency for the ganglion impar is useful for the treatment of perineal noncancer-related pain.

Other: Coccygodynia secondary to hypermobile coccyx in a 67 year old female: a case report

In this case report, the patient was a 67 year old female with a five year history of rectal and sacral pain. This is a patient with chronic, progressive rectal and sacral pain which began after a fall. Previous work-up had included an MRI of the lumbar spine and pelvis and were unrevealing. The patient was admitted to an inpatient Rehabilitation unit due to failure of pain control as an outpatient. Initial evaluation revealed significant pain with rectal exam as well as a hypermobile coccyx. The patient was sent for stress views of the coccyx using the Maigne protocol which demonstrated hypermobility on flexion views. A few days later, the patient had a diagnostic injection to the sacrococcygeal disc space as well as between the first and second coccygeal space. Post-procedure, the patient reported complete relief of pain and was pain free with mobilization of the coccyx on repeat rectal exam. Coccygodynia represents only one percent of low back pain but can be extremely debilitating. Up to 1/3 of coccygodynia cases are idiopathic but many cases are thought to arise from disruption of the sacrococcygeal joint ligaments. In these cases, a hypermobile coccyx will likely be present on exam and with stress views on plain film. Pain relief with lidocaine/steroid injection will further confirm the diagnosis and may be therapeutic. In evaluating a patient with chronic rectal and sacral pain, coccygodynia secondary to hypermobile coccyx should be considered in the differential diagnosis and thoroughly evaluated with rectal exam, plain films with stress views, and if necessary local injection with anesthetic and steroid.