An Anatomical and Morphometric Study of the Coccyx Using Three-Dimensional Reconstruction

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.

The design of a family of parametric anatomically-based compliant buttock models to evaluate wheelchair cushion performance

The evaluation of wheelchair cushion performance is of interest to a variety of stakeholders, including standards organizations, cushion manufacturers, clinicians, users and payers. The objective of this project was to develop a family of compliant buttock models that are based upon the anatomical parameters of persons with varying body sizes. The models are parametrically designed so can be scaled to evaluate different sized cushions. This paper will detail the designs, describe the anatomical basis for the design and provide the rationale for the design decisions. The manuscript also serves a secondary purpose to illustrate how anthropometric data can be applied to the design of anatomical phantoms that reflect both soft tissue and skeletal anthropometry. Supplemental material includes greater detail and the full CAD files and model fabrication instructions are available in an open access repository for persons who wish to fabricate the models.

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.

Comparison of Extracorporeal Shockwave Therapy and Blind Steroid Injection in Patients With Coccydynia: A Randomized Clinical Trial

OBJECTIVE

Extracorporeal shockwave therapy (ESWT) emerged recently for the treatment of musculoskeletal conditions owing to its regenerative and anti-inflammatory effects. In this study, the aim was to compare the efficacies of ESWT and steroid injection in patients with coccydynia.

DESIGN

Thirty-four patients with coccydynia were randomized into two groups. In the ESWT group, patients received radial shockwave for three weekly sessions. The second treatment group received an injection of steroid in the tip of the coccyx or sacrococcygeal junction. Outcome measures were visual analog scale, Short-Form Health Survey, and Dallas Pain Questionnaire. Visual analog scale was measured at baseline and 1 wk, 1 mo, 2 mos, and 6 mos after the intervention. Short-Form Health Survey and Dallas Pain Questionnaire were assessed before and 1 mo after treatment.

RESULTS

The visual analog scale score was significantly decreased in all follow-ups in both groups. There was also a significant decrease between 1 wk and three other posttreatment visits in the ESWT treatment group. Time and group interaction effect was significant on the visual analog scale (F2.64, 84.63 = 2.95, P = 0.043), in favor of ESWT. Concerning the Short-Form Health Survey and Dallas Pain Questionnaire, only some dimensions improved.

CONCLUSIONS

ESWT is an effective intervention in patients with coccydynia and had more long-lasting efficacy than steroid in terms of pain relief over 6 mos of observation.

The morphological consequences of segmentation anomalies in the human sacrum

OBJECTIVES

Despite the high frequency of segmentation anomalies in the human sacrum, their evolutionary and clinical implications remain controversial. Specifically, inconsistencies involving the classification and counting methods obscure accurate assessment of lumbosacral transitional vertebrae. Therefore, we aim to establish more reliable morphological and morphometric methods for differentiating between sacralizations and lumbarizations in clinical and paleontological contexts.

MATERIALS AND METHODS

Using clinical CT data from 145 individuals aged 14-47 years, vertebral counts and the spatial relationship between the sacrum and adjoining bony structures were assessed, while the morphological variation of the sacrum was assessed using geometric morphometrics based on varied landmark configurations.

RESULTS

The prevalence of lumbosacral and sacrococcygeal segmentation anomalies was 40%. Lumbarizations and sacralizations were reliably distinguishable based on the spatial relationship between the iliac crest and the upward or downward trajectory of the linea terminalis on the sacrum. Different craniocaudal orientations of the alae relative to the corpus of the first sacral vertebra were also reflected in the geometric morphometric analyses. The fusion of the coccyx (32%) was frequently coupled with lumbarizations, suggesting that the six-element sacra more often incorporate the coccyx rather than the fifth lumbar vertebra.

CONCLUSIONS

Our approach allowed the consistent identification of segmentation anomalies even in isolated sacra. Additionally, our outcomes either suggest that homeotic border shifts often affect multiple spinal regions in a unidirectional way, or that sacrum length is highly conserved perhaps due to functional constraints. Our results elucidate the potential clinical, biomechanical, and evolutionary significance of lumbosacral transitional vertebrae.

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.

Observations of different types of sacra in Greyhounds based on the occurrence of sacrocaudal fusion

Little attention has been paid to the normal fusion of the vertebrae of greyhounds despite the common occurrence of sacrocaudal fusion. The current study aimed to investigate and provide data on the morphology of different types of fused sacra (B, C and D) in greyhounds and also to determine the potential association between the sex, body mass and morphology of fused sacra (S. Weight, S. Length and S. Width) in greyhounds. The sacra were collected from 171 greyhounds from Melbourne, Australia. After classifying the sacra based on the occurrence and types of the sacrocaudal fusion, they were measured for weight of the sacrum, length of sacrum and the width of sacrum. Multiple linear regression analyses were used to quantify the association between weight of the sacrum (as the outcome variable) type of sacrum (A, B, C and D), body mass and sex (as explanatory variables). The results proved that there are measurable differences between each type of fused sacra (B, C and D) and the standard sacra (A). In addition, this study showed that sex or body mass do not influence the occurrence of different types of fusion. The results of this study showed that the occurrence of sacrocaudal fusions was independent of body size in this population of greyhounds. Sacrocaudal fusion might affect the biomechanics in greyhounds independently of effects of body size.

The Value of CT Three-Dimensional Reconstruction in Nursing and Diagnosis of Senile Hip Fracture

Aim

To study the diagnostic effect of hip fracture in the elderly. In this paper, a total of 100 elderly patients with hip fracture from January 2020 to May 2021 were selected for X-ray and CT examination after admission. The operation was taken as the final criteria for determining hip fracture type, and the diagnosis of hip fracture by CT three-dimensional reconstruction was analyzed and studied. The results showed that the diagnostic rate of CT 3D reconstruction for various types of hip fracture in the elderly was higher than that of CT plain scan and X-ray (P < 0.05). For the diagnosis of intra-articular small bone fragments, the rate of missed diagnosis was 2% (2/100) with CT 3D reconstruction, 10% (10/100) with conventional CT scan, and 20% (20/100) with X-ray. The rate of misdiagnosis was 5.0% (5/100) with CT 3D reconstruction. Routine CT scan was 15% (15/100), X-ray was 30% (30/100), and CT 3D reconstruction was significantly lower than other examinations (P < 0.05).

Conclusion

CT 3D reconstruction has high accuracy in the diagnosis of various types of hip fractures in the elderly.

Visualizing Tissue Strain Under the Sacrum and Coccyx in Different Supine Postures: A Case Series

OBJECTIVE

To visually assess and report the influence of supine positioning and sacrum and coccyx anatomy on tissue deformation.

METHODS

A convenience sample of three participants was scanned using MRI. All participants were scanned in a supine position with a rig oriented in a flat or horizontal position and with the torso portion of the rig elevated to 30° to simulate head-of-bed elevation. Representative images were identified to visualize and depict (1) the differences in tissue thickness and deformation in response to changes in supine positioning (0° and 30°), (2) the relative displacement of the skeleton relative to the skin during 30° incline, and (3) differences in sacrococcygeal morphology.

RESULTS

The tissue thickness under the sacrum stayed the same or increased when torsos were elevated. Skeletons were displaced relative to the skin when the rig was elevated regardless of the pelvis location. Further, in the elevated position, coccyges flexed when pelvises were placed on the elevated segment but did not flex when pelvises were placed on the horizontal segment.

CONCLUSIONS

This case series is useful in defining new areas of research that can (1) identify the deformation induced by normal and frictional forces resulting from different positions of the bed chassis, (2) assess the impact of positioning the pelvis on elevated versus horizontal segments of the bed chassis, and (3) define the association between sacral and coccyx morphology and pressure ulcer occurrence in hospitalized patients.

Coccygeal Morphology on Multislice Computed Tomography in a Tertiary Hospital in India

Study Design

A retrospective, cross-sectional study of 213 patients who presented for abdominal computed tomography (CT) scans to assess coccygeal morphology in the Indian population.

Purpose

There have been relatively few studies of coccygeal morphology in the normal population and none in the Indian population. We aimed to estimate coccygeal morphometric parameters in the Indian population.

Overview of Literature

Coccygeal morphology has been studied in European, American, Korean, and Egyptian populations, with few differences in morphology among populations.

Methods

A retrospective analysis of 213 abdominal CT scans (114 males and 99 females; age, 7–88 years; mean age, 47.3 years) was performed to evaluate the number of coccygeal segments, coccyx type, sacrococcygeal and intercoccygeal fusion and subluxation, coccygeal spicules, sacrococcygeal straight length, and sacrococcygeal and intercoccygeal curvature angles. Results were analyzed for differences in morphology with respect to sex and coccyx type.

Results

Types I and II coccyx were the most common. Most subjects had four coccygeal vertebrae; 93 subjects (43.66%) had partial or complete sacrococcygeal fusion. Intercoccygeal fusion was common, occurring in 193 subjects. Eighteen subjects had coccygeal spicules. The mean coccygeal straight length was 33.8 mm in males and 31.5 mm in females; the mean sacrococcygeal curvature angle was 116.6° in males and 111.6° in females; the mean intercoccygeal curvature angle was 140.94° in males and 145.10° in females.

Conclusions

Type I was the most common coccyx type in our study, as in Egyptian and Western populations. The number of coccygeal vertebrae and prevalence of sacrococcygeal and intercoccygeal fusion in the Indian population were similar to those in the Western population. The mean coccygeal straight length and mean sacrococcygeal curvature angle were higher in males, whereas the intercoccygeal curvature angle was higher in females. Information on similarities and differences in coccygeal morphology between different ethnic populations could be useful in imaging and treating patients presenting with coccydynia.