An exploratory study of pelvis anatomy to revise the bony canal used for LC2 screw insertion.

BACKGROUND: Percutaneous screw placement, especially the insertion of LC2 screws, is technically demanding. Although the traditional LC2 bony canal spans the anterior inferior iliac spine (AIIS) to the posterior superior iliac spines (PSIS), a high perforation rate has been reported. OBJECTION: The aim of this research was to design a revised bony canal, measure the canal width and length and guide the insertion of LC2 screws for pelvic fractures. MATERIALS AND METHODS: The plane tool in the Mimics analysis menu was used to draw a midplane connecting the midpoint between the anterior inferior spine and the PSIS upper flat region with pelvic CT data. The minimum widths of the upper, middle, lower surfaces of the tunnel and perforation rate were measured and compared. The ideal screw length was also measured along the longitudinal axis running through the midpoint of the midplane. RESULTS: The minimum widths of the upper, middle and lower surfaces of the revised canal were 3.63 mm, 7.7 mm, and 11.93 mm, respectively, in males and 5.97 mm, 9.93 mm, and 12.45 mm, respectively, in females. Significant differences were observed among the upper, middle and lower surfaces of the revised canal in male patients (P < 0.001). In female subjects, the upper canal surface was significantly different from the middle and lower canal surfaces (P < 0.001). The perforation rate was significantly decreased especially in females pelvic. The channel length passing through the midpoint of the narrowest position of the pelvis was 130.85 ± 8.02 mm in males and 124.30 ± 7.71 mm in females and was significantly different for male and female pelvises (P = 0.004). CONCLUSION: The LC2 screw should be inserted along the intersection line of the AIIS lateral wall and the iliac body. The screw should be inserted under the line between the midpoint of the AIIS and the PSIS upper flat region to ensure accuracy of placement. LC2 screws can be more easily inserted in males than in females, and the rate of cortical perforation can be significantly decreased under the guidance of the newly proposed canal.

Examination of canalis sinuosus using cone beam computed tomography in an Australian population.

BACKGROUND: Canalis sinuosus (CS) and its relationship with adjacent teeth is relevant for surgery in the anterior maxilla. Therefore, the aim of this study was to report the prevalence, characteristics and variations of CS. METHODS: Cone beam computed tomography (CBCT) scans of the anterior maxilla of 201 patients were reviewed. CS and the adjacent teeth were analysed by age, gender and scan resolution, using analysis of variance, Chi-squared and Fisher's exact tests. The widest and narrowest diameters of CS, and distance to tooth apex (DTA), were compared by quadrant, closest tooth and location, and the associations were examined statistically with P < 0.05. RESULTS: In the 201 scans, 412 CS were identified in 198 patients associated with 395 different teeth. Mean widest diameter was 1.08 ± 0.39 mm (range: 0.42-2.60 mm), while the narrowest diameter was 0.71 ± 0.26 mm (range: 0.25-1.59 mm); and mean DTA of 2.16 ± 1.25 mm (range: 0-6.22 mm). CS detection was significantly lower with CBCT taken at resolution size of 0.250 voxels (P = 0.02). CONCLUSIONS: CS was very common in the anterior maxilla. Clinicians would be well advised to identify this anatomical structure using CBCT before undertaking any surgery in the anterior maxilla. © 2022 Australian Dental Association.

[Computer tomography demonstrations of single-sided deafness].

Objective:To investigate the distribution of common inner ear and internal auditory canal malformations in children with single-sided deafness（SSD） ,and to explore the imaging etiology of SSD by comparing the quantitative parameters of key bone structures between deaf and normal ears in children with congenital SSD. Method:Forty children with SSD diagnosed in the Second Hospital of Lanzhou University from September 2016 to March 2019 were collected. All of them underwent HRCT examinations of temporal bone . The area of bone island, the width of vestibular, the width of internal auditory canal, the height of cochlear and the width of cochlear basal axis were measured. Paired t test was used to compare the difference between the hearing abnormality and normal hearing in children with SSD. Result:The rate of inner ear deformity was 62.5% in SSD group,the most common deformity was cochlear nerve canal deformity, 20 cases （50.0%） of cochlear canal stenosis and 3 cases （7.5%） of cochlear canal atresia.The second most common deformity was internal auditory canal deformity, including 5 cases （12.5%） of internal auditory canal stenosis and 1 case （2.5%） of internal auditory canal atresia. Other malformations included 1 case（2.5%） of RO, 2 cases （5.0%） of incomplete partition （IP） type II and 1 case （2.5%） of enlargement of vestibular aqueduct （EVA）. There are no significant difference in the measured results of the key structures of the inner ear between two groups except the width of cochlear nerve canal, internal auditory canal and the area of bone island. Conclusion:The main inner ear deformities in children with SSD are cochlear nerve canal stenosis and inner auditory canal stenosis. HRCT of temporal bone has high diagnostic value for inner ear deformities in children with SSD.

Lumbar Canal Diameter Evaluation by CT Morphometry-Study of Indian Population.

STUDY DESIGN: A cross-sectional study. BACKGROUND: To document dimensions of the lumbar vertebrae and bony canal in an Indian population and to compare with other studies from the subcontinent as well as from other parts of world. METHODS: An observational study was conducted on the basis of a review of thin-cut (3 mm) computed tomographic images of lumbar vertebrae. A total of 302 patients were studied, and various dimensions were analyzed. RESULTS: In general, the vertebral and bony spinal canal dimensions were found to be greater in male patients. Comparison of populations revealed statistically significant differences in the spinal canal between an Indian population and others. OVERVIEW OF LITERATURE: Lumbar canal stenosis is a condition in which the anteroposterior and lateral dimensions of the bony spinal canal are less than normal for corresponding age and sex. Numerous studies have been conducted to determine morphometry of the lumbar vertebrae and spinal canal, mostly in western populations, using fresh cadaver or osteologic specimens. These studies did not mention the difference between the vertebral parameters in men and women. Moreover, many of these studies have limitations such as a small sample size and lack of demographic data including race, age, and sex. In this study, we have conducted morphometric analysis of the lumbar vertebrae in a relatively large number of Indian patients by using computed tomography scan. The morphometric data thus compiled may provide a baseline of body and canal dimensions that could guide clinical experts in their practice. CONCLUSIONS: The dimensions of the lumbar vertebrae and bony canal thus obtained shall provide a baseline normative data for evaluation of patients presenting with low backache and lumbar canal stenosis in an Indian population.

Morphometry of organization of middle meningeal artery through the analysis of bony canal in human's skull: A clinico-anatomical and embryological insight.

BACKGROUND: Middle meningeal artery (MMA) is the largest branch of the maxillary artery supplying meninges of the cranial cavity. The complexity of MMA development gives many opportunities for anatomical variation. Besides, the variant MMA can be easily injured when dealing with fractures of the base of the skull, epidural hematomas, and bypass procedures. Although various aberrant origins of the MMA have been documented in the literature, there is a lack of detailed morphometric aspects of this important arterial segment. Thus, in this study, we investigated the anatomical organization of the MMA through the bony canal measurements from human skulls to improve surgical results. MATERIALS AND METHODS: Seventy-five adult dry skulls were investigated. Angle of the main trunk, length of the main trunk, angle between the frontal and parietal branches, length of the frontal branch, length of the parietal branch, and length of the bony tunnel formed by the frontal branch were measured bilaterally. RESULTS: In the present study, we found significant differences between the parameters such as length of frontal (P = 0.034) and parietal (P = 0.023) branches and length of bony tunnel (P = 0.045) of right and left sides, but there was no significant difference found in the rest of the parameters. CONCLUSIONS: Morphometry of the bony canal of MMA shall be important for safely expose and preserve the artery during craniotomy with careful drilling and shall be useful for those who have interest in this anatomical site.

Intracranial Bony Canal of the Middle Meningeal Artery - Morphological and Histological Analysis.

The middle meningeal artery (MMA) can play an important role in the surgical revascularization. However, the MMA can be easily injured if it passes through a bony canal. We investigated the morphological and histological features of the bony canal to improve surgical results. MATERIALS AND METHODS: Fifty adult dry skulls were investigated. The length of the bony canal and the distance from the orbital rim to the bony canal were measured. Additionally, 28 cadaveric heads were examined histologically. RESULTS: Sixty-three bony canals were found in 43 skulls. The mean length of bony canals was 9.2 mm, and the mean distance from the orbital rim was 24.0 mm. The bony canal ran mainly from the sphenoid bone (69.8%) to the parietal bone (73.0%). Histologically, both sides of the meningeal grooves gradually closed the distance, and formed the bony canal. The MMA inside the bony canal was enveloped with collagen tissues, divided into branches, and was accompanied by the vein. CONCLUSIONS: The bony canal is located around the pterion and is formed during bone growth. The MMA is covered with collagen tissues inside the bony canal. It is possible to safely expose and preserve the MMA during craniotomy with careful drilling.

The Pathomorphologic Study of Spinal Stenosis as Seen on CT - Myelography of the Lumbar

This study has been examined different morphologic measurements in the evaluation of patients with lumbar spinal stenosis. Preoperative CT-Myelography from 30 patients who underwent surgery for central lumbar stenosis were analyzed. Based on this, we concluded as follows : 1) Bony measurement alone did not reliably identify patients with spinal stenosis. 2) Measurement of the transverse area of the dural sac on CT-Myelography was the most accurate method for identifying stenosis. 3) Lumbar myelography was still considered to have an important role in the valuation of a patient with stenosis because of correlation between the cross-sectional area of the dural sac and the anteroposterior diameter of the dural sac was excellent. 4) We identified soft-tissue problems as the main cause of stenosis. 5) The most common level of maximum stenosis was L4-5.