Sacrococcygeal Morphologic and Morphometric Risk Factors for Idiopathic Coccydynia: A Magnetic Resonance Imaging Study

Predictors of outcomes of conservative management in chronic coccydynia - Results from a prospective clinicoradiological observational study

Study background

Chronic coccydynia is a difficult pathology to treat due to limited understanding of the etiology and risk factors. Aim of the study was to analyse the clinical and radiological factors associated with poor outcomes in coccydynia.

Study design

Prospective observational study.

Methods

Patients who visited the spine outpatient department between September 2019 to August 2021 with coccygeal pain of more than two months were included in the study. Lateral radiographs in seated and standing position were done to evaluate their Intercoccygeal angle (ICA), Sacrococcygeal angle (SCA), Basal Angle (BA) and Coccygeal Length. MRI was done for patients who were not relieved with 2 months of conservative treatment. Baseline VAS and ODI scores were documented at the first visit and at six months follow-up to evaluate the outcomes.

Results

168 patients were included - 106 females and 62 males (M:F ratio 1.76) with a mean age of 41.71 years. 109 out of 168 (64.9 %) were obese and 31(18.5 %) were overweight. Type 2 and 4 coccyges were the most commonly seen morphology (67 patients each). Traumatic coccydynia had a better outcome with a mean VAS score of 3.54 compared to 4.36 in the idiopathic group(p < 0.05). Higher Intercoccygeal angle (ICA) was the only radiographic parameter that had coorelation with the outcomes. Mean ICA in good outcomes group was 34.8° (13.2) compared to 42.1° (14.6) in those with poor outcomes(p < 0.05). All 7 patients with pseudoarthrosis had VAS scores reduction of more than 50 %.

Conclusion

Type 2 and type 4 were the most common coccyx morphology encountered in patients with chronic coccydynia. Outcomes were better in traumatic group compared to idiopathic group and in those with pseudoarthrosis on MRI. Higher Intercoccygeal angle(ICA) was the only radiographic parameter associated with poor outcome of conservative management.

Imaging findings and treatment in coccydynia - update of the recent study findings

BACKGROUND

Coccydynia is one of the most overlooked symptoms in clinical practice. The diagnosis and radiologic findings of traumatic coccyx can be more easily detected unless it is delayed and postponed. For idiopathic coccydynia, which accounts for one third of cases, patients present with long-standing pain and multiple physician visits.

METHOD

The keywords coccyx, coccydynia, coccygodynia were searched in PubMed, Embase, Scopus databases in the last 5 years. Research articles, reviews and case reports were analyzed. The studies conducted in the last 5 years were presented under the headings of etiology, radiologic assessment, interventional and surgical treatments.

RESULTS AND CONCLUSION

The first step is dynamic X-ray of the coccyx in standing and sitting position. In this way, morphologic parameters and hypermobility causing idiopathic coccydynia can be evaluated. Morphologic and morphometric features of the coccyx described in previous CT and MR studies have explained the relationship with coccydynia. The key features are as follows: Type II coccyx morphology, subluxation of the intercoccygeal joint, presence of bony spicules. Knowledge of these definitions as well as the differential diagnosis in this anatomical region will help in reaching the correct diagnosis. The treatment of coccydynia is stepwise like the diagnosis. Conservative treatments are initiated first. Manipulations, ganglion impar block, injections, radiofrequency and shock treatments and finally coccygectomy are treatment methods reported. Radiologists should not overlook this region and should be familiar with the coccyx's morphologic appearance and the sacrococcygeal region's differential diagnosis.

KEY POINTS

· The etiology of coccydynia usually includes trauma, obesity and female sex, special coccyx morphology, and coccygeal hypermobility.. · Coccyx fractures are defined into three groups as flexion type 1, compression type 2, and extension type 3.. · When evaluating coccydynia, the first step is a dynamic X-ray examination of the coccyx in standing and sitting position.. · Hypermobility is defined as more than 25 % posterior subluxation while sitting or more than 25° flexion while sitting.. · More than 35° posterior subluxation is considered significant hypermobility..

CITATION FORMAT

· Sukun A, Cankurtaran T, Agildere M et al. Imaging findings and treatment in coccydynia - update of the recent study findings. Fortschr Röntgenstr 2024; 196: 560 - 572.

Coccydynia: A Review of Anatomy, Causes, Diagnosis, and Treatment

» Coccydynia is a painful condition affecting many patients at the terminal caudal end of the spine.» An understanding of coccyx anatomy and variations of morphology is necessary for proper diagnosis. A multifactorial etiology for pain may be responsible for this clinical entity.» Several treatment options exist. Successful outcomes for patients depend on individual patient characteristics and the etiology of pain.

The overlooked symptom of coccydynia: evaluation of sacrococcygeal morphologic and morphometric findings

BACKGROUND

Coccydynia is one of the most overlooked symptoms in daily clinical practice. Definitions for radiologic evaluation are controversial.

OBJECTIVES

We aimed to compare the morphology and morphometric measurements of the sacrococcygeal region with those of a healthy population to support radiologic decision-making.

MATERIALS AND METHODS

In total, 26 traumatic and 50 idiopathic cases of coccydynia as well as 74 healthy control cases were retrospectively compared. The morphologic type of the coccyx, the presence of fusion, and the number of coccygeal segments were evaluated in both groups. Morphometric parameters such as sacrococcygeal angle (SCA), sacrococcygeal joint angle (SCJA), intercoccygeal angle (ICA), sacral slope (SS), coccyx curved length (CCL), sacrum curved length (SCL), coccyx length (CL), sacrum length (SL), and sacrococcygeal total length (SCTL) were investigated.

RESULTS

Significant differences were found between the coccydynia group and the healthy control group in morphologic parameters such as female gender, coccyx segment, coccyx morphology, presence of sacrococcygeal joint, and segment of sacrococcygeal joint fusion (p < 0.05). In morphologic measurements, SCJA, SCL, SL, coccyx and sacrum curvature indexes were significantly increased (p < 0.05). No significant difference was found in the morphologic and morphometric parameters evaluated when compared with the duration of coccydynia (p > 0.05).

CONCLUSION

An increase in the SCJA, SCL, SL, SCI, and coccyx curvature index measurements predisposes to coccydynia. It would be more accurate to perform radiological evaluation by familiarization with these morphologic and morphometric parameters.

Sacralization of Coccygeal Vertebra: A Descriptive Observational Study in Bangladesh

Background: In the sacrococcygeal region, anatomical variation is due to the sacralization of the coccygeal vertebra, which is the due union of/fusion of the fifth sacral with the first coccygeal vertebra of five couples of sacral foramina under-detected or asymptomatic beyond radiological assessment. That is why it is challenging to know the cause of coccydynia, caudal block failure, the difficult second stage of labor, and perineal tears. The present study aims to improve knowledge about the anatomical variation of sacralization of the coccygeal vertebra. Additionally, to find the prevalence of sacralization of coccygeal vertebra in Sylhet, Bangladesh.

Methods: This study was performed on 60 parched, totally calcified, typical sacra of mature-age individuals of undetermined sexes, fulfilling the inclusion criteria from the bone bank of the osteology museum of the Department of Anatomy, Sylhet MAG Osmani Medical College, Sylhet, Bangladesh, from July 2017 to June 2018. Sex determination of the collected unknown sacra was conducted using discriminant function analysis. It was found that 50% (30) were male and 50% (30%) were female. The unpaired t-tests and chi-square were utilized to determine the statistical significance.

Results: Out of 60 sacra, eight (13.33%) samples presented with sacralization. This study found that males had significantly higher straight (p=0.05) and curved (p=0.05) lengths of sacrococcygeal vertebrae. The sacrococcygeal curvature index (SCI) showed statistically significant (p=0.05) differences between the sexes.

Conclusion: Sacralization may exert an impact on the caudal block. It could extend the second stage of the labor process with perineal tears. Therefore, knowledge about the anatomical variation of the coccygeal vertebra is essential.

Morphological Features of the Coccyx in the Turkish Population and Interrelationships Among the Parameters: A Computerized Tomography-Based Analysis

Introduction

The coccyx is well-known to be a highly variable structure considering its morphology. To our knowledge, the relationship between the coccygeal types and other morphological features has not been studied yet. In addition to the interrelations among morphological parameters, this study investigated the morphology and morphometry of coccyx more extensively in the adult Turkish population using computerized tomography images.

Methods

Five hundred subjects who underwent pelvic computerized tomography were included in this study. In addition to coccyx type and the counts of coccygeal vertebrae and segments, the presence of coccygeal deviation, sacrococcygeal joint (SCJ) fusion, SCJ subluxation, intercoccygeal joint (ICJ) fusion, and coccygeal spicule were evaluated. The coccygeal length, sacrococcygeal angle, and intercoccygeal angle were measured on the digital workstation. The findings were subjected to statistical analyses.

Results

The coccygeal vertebra count ranged between three to five, with an average of 4.04 ± 0.48. The range of coccygeal segment count was between one and five, with an average of 2.53 ± 1.02. ICJ fusion in any segment, SCJ fusion, and SCJ subluxation were identified in 397 subjects (79.4%), 343 subjects (68.6%), and 17 subjects (3.4%), respectively. The coccyx types from the most common to the least common were as follows: type 2, type 1, type 3, type 4, and type 5. Coccygeal deviation to the left side was observed in 71 subjects (14.2%), while coccygeal deviation to the right side was observed in 61 subjects (12.2%). A coccygeal spicule was identified in 73 subjects (14.6%). The subjects’ mean age demonstrated no significant difference considering the ICJ fusion (p=0.271), SCJ subluxation (p=0.51), coccygeal spicule (p=0.337), features of coccygeal deviation (p=0.83), and coccyx types (p=0.11). The subjects with SCJ fusion (50.7 ± 18.3 years) were significantly older than the subjects without SCJ fusion (46.5 ± 18.5 years) (p=0.016). The differences between the coccyx types considering the rate of SCJ fusion (p=0.002), ICJ fusion (p=0.04), and spicule presence (p<0.001) as well as the coccygeal vertebra count (p<0.001) were significant.

Conclusion

The presence of coccygeal spicule, a risk factor for coccydynia, is reported to be 14.6% in this study group that represents the Turkish population. This study indicates an association between the coccyx types and the frequency of SCJ fusion, ICJ fusion, and spicule presence and consequently suggests the significance of the coccyx type among the morphological features to cause susceptibility to coccydynia. Due to the multiplicity of the pain generators in the coccygeal region that is established by previous reports, the comparisons of different human populations and the knowledge on the interrelations between the morphologic parameters might facilitate the comprehension of the etiology of coccydynia. The clarification of interrelationship existence among the coccygeal morphological parameters requires further investigations.