Computed tomography-based morphologic and morphometric features of the coccyx among Arab adults

Imaging study of coccygeal morphology in adolescent idiopathic scoliosis

The correlation between scoliosis and sagittal curvature of the cervical, thoracic, and lumbar spine have already been reported in previous studies. However, as a part of the spine, the change in coccygeal morphology in AIS patients has not yet been studied. In this study, a retrospective analysis was performed on 400 patients who were divided into a non-scoliotic group (206 patients) and an AIS group (194 patients). The Postacchini coccygeal radiological classification that was modified by Nathan was used to observe and compare the sagittal coccygeal morphology between the two groups. The results showed that the non-scoliotic group had the highest percentage (52.4%) of patients with type I and the lowest (3.4%) proportion of patients with type V; moreover, the AIS group had the highest percentage (69.1%) of patients with type I and the lowest (1.5%) proportion of patients with type V. The coccygeal morphology was significantly different between the non-scoliotic group and the AIS group (P = 0.001). No significant differences in coccygeal morphology were found between the males and females in the two groups (mild and moderate scoliosis and different segmental scoliosis). In addition, a significant correlation between coccygeal morphology and scoliosis (P = 0.035) was found. In conclusion, coccygeal morphology significantly differs between AIS patients and non-scoliotic adolescents. There was a smaller proportion of patients with a type I coccyx and a larger proportion of patients with a type II or type III coccyx in the AIS group than in the non-scoliotic group. In other words, the presence of a more pronounced coccygeal curve in AIS patients may be caused by an incorrect sitting position and an imbalance in the contraction of the pelvic muscles. It should be further studied whether correcting the sitting position and muscular imbalances could change coccygeal morphology and subsequently affect the development of AIS.

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

STUDY DESIGN

Retrospective case-control study.

OBJECTIVES

To evaluate the sacrococcygeal morphologic and morphometric features in idiopathic coccydynia using magnetic resonance imaging (MRI).

METHODS

MRI scans from 60 patients with idiopathic coccydynia were compared with scans of 60 controls. Assessment of coccygeal morphology included coccygeal segmentation, coccygeal types, bony spicules, sacrococcygeal joint fusion, and intercoccygeal joint fusion and subluxation. Morphometric parameters included coccygeal straight and curved lengths, coccygeal curvature index, sacrococcygeal and intercoccygeal joint angles, sacral straight and curved lengths, sacral curvature index, sacral angle, sacrococcygeal straight and curved lengths, sacrococcygeal curvature index, and sacrococcygeal angle.

RESULTS

The coccydynia group included 28 males and 32 females, with a mean age of 36.1 years. Type II coccyx and bony spicules were more common in coccydynia, P = 0.003 and 0.01, respectively. Sacrococcygeal joints were fused less commonly in coccydynia, P = 0.02. Intercoccygeal joint subluxation was more common in coccydynia, P = 0.007. The sacral angle was lower in coccydynia, P = 0.01. The sacrococcygeal curved length was higher in coccydynia, P < 0.001. The sacrococcygeal curvature index was lower coccydynia, P < 0.001. In females only, the coccygeal curvature index was lower in coccydynia patients, P = 0.04. In males only, the intercoccygeal angle was lower in coccydynia patients, P = 0.02.

CONCLUSIONS

Type II coccyx, bony spicules, intercoccygeal joint subluxation were more common, and sacrococcygeal joint fusion was less common in coccydynia patients. Sacral angle and sacrococcygeal curvature index were lower, while sacrococcygeal curved length was higher in coccydynia patients.

LEVEL OF EVIDENCE

Level 3. Case-control study.

Does Sacrococcygeal Skeletal Morphology and Morphometry Influence Pressure Injury Formation in Adults?

GENERAL PURPOSE

To present a study that investigated sacrococcygeal skeletal structure as a possible nonmodifiable intrinsic risk factor for pressure injury and identify possible issues caused by its morphology.

TARGET AUDIENCE

This continuing education activity is intended for physicians, physician assistants, nurse practitioners, and nurses with an interest in skin and wound care.

LEARNING OBJECTIVES/OUTCOMES

After participating in this educational activity, the participant will:1. Recognize the background information the authors considered when planning and conducting their study of sacrococcygeal skeletal structure as a possible pressure injury risk factor.2. Identify the characteristics of the two groups of study participants.3. Choose the results of the study clinicians may consider when implementing evidence-based practice.

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.

The analysis of sacrum and coccyx length measured with computerized tomography images depending on sex

Background

Sex estimation is vital in establishing an accurate biological profile from the human skeleton, as sex influences the analysis of other elements in both Physical and Forensic Anthropology and Legal Medicine. The present study was conducted to analyze the sex differences between the sacrum and coccyx length based on the measurements calculated with computed tomography (CT) images. One hundred case images (50 females, 50 males) who were between the ages of 25 and 50 and admitted by the emergency department between September 2018 and June 2019 and underwent CT were included in the study. Eighteen lengths, 4 curvature lengths, and 2 regions were measured in sagittal, coronal and transverse planes with orthogonal adjustment for three times.

Results

It was stated that the mean anterior and posterior sacral length, anterior and posterior sacrococcygeal length, anterior and posterior sacral curvature length, anterior coccygeal curvature length, sacral area, lengths of transverse lines 1, 2, 3 and 4, sacral first vertebra transverse and sagittal length measurements were longer in males when compared to females (p < 0.05). It was noted that the parameter with the highest discrimination value in the receiver operating characteristic (ROC) analysis was the sacral area (AUC = 0.88/Acc = 0.82). Based on Fisher’s linear discriminant analysis findings, the discrimination rate was 96% for males, 92% for females and the overall discrimination rate was 94%.

Conclusions

It was concluded that the fourteen parameters that were indicated as significant in the present study could be used in anthropology, Forensic Medicine and Anatomy to predict sex.

Three-dimensional evaluation of the coccyx movement between supine and standing positions using conventional and upright computed tomography imaging

Currently, no three-dimensional reference data exist for the normal coccyx in the standing position on computed tomography (CT); however, this information could have utility for evaluating patients with coccydynia and pelvic floor dysfunction. Thus, we aimed to compare coccygeal parameters in the standing versus supine positions using upright and supine CT and evaluate the effects of sex, age, and body mass index (BMI) on coccygeal movement. Thirty-two healthy volunteers underwent both upright (standing position) and conventional (supine position) CT examinations. In the standing position, the coccyx became significantly longer and straighter, with the tip of the coccyx moving backward and downward (all p < 0.001). Additionally, the coccygeal straight length (standing/supine, 37.8 ± 7.1/35.7 ± 7.0 mm) and sacrococcygeal straight length (standing/supine, 131.7 ± 11.2/125.0 ± 10.7 mm) were significantly longer in the standing position. The sacrococcygeal angle (standing/supine, 115.0 ± 10.6/105.0 ± 12.5°) was significantly larger, while the lumbosacral angle (standing/supine, 21.1 ± 5.9/25.0 ± 4.9°) was significantly smaller. The migration length of the tip of the coccyx (mean, 7.9 mm) exhibited a moderate correlation with BMI (r = 0.42, p = 0.0163). Our results may provide important clues regarding the pathogenesis of coccydynia and pelvic floor dysfunction.

Morphological evaluation of the coccyx with multidetector computed tomography

PURPOSE

This study aims to evaluate the morphology of the coccyx in adults with multidetector computed tomography and to contribute to the classification of the coccyx using intercoccygeal and sacrococcygeal angle measurements.

METHODS

The pelvic computed tomography images of 224 patients were retrospectively evaluated. The multiplanar reconstruction and 3D volume rendering images of the coccyx were obtained from all patients at sagittal and coronal planes. The morphology of the coccyx, number of bone segments, the presence of scoliosis, and presence of sacrococcygeal and intercoccygeal fusion were evaluated. After the measurement of coccygeal length, width, and thickness, intercoccygeal and sacrococcygeal angles were also calculated in all patients.

RESULTS

The morphological classification showed that 136 patients (60.7%) had type 1, 65 patients (29%) had type 2, and 17 patients (7.6%) had type 3 coccyx. The intercoccygeal angle was zero degree in five patients (type 0) and one patient had retroverted coccyx (type 5). The coccyx had four segments in 155 patients (69.2%), three segments in 52 patients (23.2%), five segments in 15 patients (6.7%), two segments in one patient (0.4%), and one segment in one patient (0.4%).

CONCLUSION

We determined patients with an intercoccygeal angle of zero degree, which is not mentioned in the literature before, and we propose to use the term "type 0" for these patients in the classification of coccyx. The coccygeal measurements and classification will be instructive for the radiologists and have a guiding role for the future studies.

Magnetic Resonance Measurements of Sacrococcygeal and Intercoccygeal Angles in Normal Participants and those with Idiopathic Coccydynia

BACKGROUND

In the past, few studies have been done to objectively measure the sacrococcygeal (SC) and intercoccygeal (IC) angles in the population and in patients with coccydynia. Coccydynia is an age-old disorder, the exact incidence of which has not been determined. It is reported to be more common in females and the obese. The magnetic resonance imaging (MRI) studies done in the past have calculated the curvature indices. In this study, we used MRI to objectively measure the angles in the normal participants as well as those with idiopathic coccydynia.

MATERIALS AND METHODS

Two groups of patients were identified. Group A was "control group" of 106 normal participants and Group B comprised "study group" of ten patients suffering from idiopathic coccydynia. In all these patients, midsagittal T1-weighted MRI image acquired in supine position was used to calculate SC and IC angles. Data were analyzed, and angles were compared between the study and control groups. Statistical analysis was done with Chi-square test.

RESULTS

In the control group, the average SC and IC angles in the control group were 126.8° and 33.5°, respectively. In the study group, the average SC angle and the average IC angle turned out to be 127.1° and 43.2°, respectively. The difference between the SC angles in the control and study groups was not significant (P = 0.7), whereas the difference between the IC angles in the two groups was significant (P = 0.002).

CONCLUSIONS

From our study, we observed that the IC angle shows a decreasing trend with increasing age. In addition, increased IC angle was identified as a possible cause of idiopathic coccydynia.

Analysis of Sacrococcygeal Morphology in Koreans Using Computed Tomography

Background

The sacrococcygeal morphology of Arabs and Europeans has been studied using computed tomography (CT) or magnetic resonance imaging to determine the cause of coccydynia. Studies have suggested differences in sacrococcygeal morphology among ethnic groups. However, there are no data on the sacrococcygeal anatomy of Koreans.

Methods

We conducted a retrospective analysis of 606 pelvic CT scans that were taken at Cheju Halla General Hospital between 2008 and 2014. Fractures of the sacrum or coccyx were excluded. Differences in the sacrococcygeal morphology among age groups stratified by decade of life and between genders were analyzed using sagittal plane pelvic CT scans. The morphological parameters studied were the sacral and coccygeal curved indexes, sacrococcygeal angle, intercoccygeal angle, coccygeal type, coccygeal segmental number, and sacrococcygeal fusion.

Results

The average sacral and coccygeal curved indexes were 6.15 and 7.41, respectively. The average sacrococcygeal and intercoccygeal angles were 110° and 49°, respectively. Type II coccyx was most common, and the rate of sacrococcygeal fusion was 34%. There was a moderate positive correlation between age and the sacral curved index (r = 0.493, p = 0.000) and a weak negative correlation between age and the coccyx curved index (r = −0.257, p = 0.000). There was a weak negative correlation between age and the intercoccygeal angle (r = −0.187, p = 0.000). The average intercoccygeal angle in males and females was 53.9° and 44.7°, respectively.

Conclusions

The sacrum tended to be more curved and the coccyx straighter with age. The coccyx was straighter in females than males. Knowledge of the sacrococcygeal anatomy of Koreans will promote better understanding of anatomical differences among ethnicities and future studies on coccydynia.