Background With the continuous improvement of diagnosis and treatment technology for cervical spine-related diseases in children at home and abroad, the demand for exploring the developmental anatomy and function of children's cervical spine of different ages is increasing. So the aim of this study was to investigate the changes of anatomical indicators in neurocentral synchondrosis (NCS) of C 2 ~ C 7 with age and the developmental characteristics of different vertebrae in children aged 1 ~ 6 years old. Method A retrospective collection of 160 cases of normal cervical spine CT images of children aged 1 ~ 6 years old in provincial tertiary hospitals, according to the age group of 1-year-old into 6 groups. The original data of continuously scanned cervical spine tomography images were imported into Mimics16.0 software, under the two-dimensional image window, selected the measurement tool under the Measurements toolbar to measure and statistically analyzed the anatomical indicators such as cross diameter, sagittal diameter, height, perimeter and area of NCS in the C 2 ~ C 7 segment of the cervical spine on the coronal plane and cross-section. Results There was no significant difference in the anatomical indexes of cervical spine NCS in children compared with the left and right sides of the same vertebrae ( P > 0.05). The same cervical spine generally had differences between the age groups of 1 ~ 4 years old and 5 ~ 6 years old ( P < 0.05).The transverse diameter and circumference gradually decreased with age; the sagittal diameter and height showed a slight increase trend; there was a maximum area at 2 years of age. In different cervical vertebrae of the same age group, the NCS values of C 3 , C 4 ,and C 5 varied greatly, which showed that the ossification process of cervical cartilage was faster than that at the upper and lower ends. There were obvious differences between C 2 and the rest of the cervical vertebral segments’ NCS ossification process. C 7 was also very different from the rest of the cervical vertebrae segments, presumably more similar to the thoracic spine. Conclusions The anatomical indexes of C 2 ~ C 7 NCS in children have obvious developmental regularities at different ages, and there are also regularities between cervical segments.

OBJECTIVE:To investigate the anatomical indexes and anatomical positional indexes of the atlantoaxial synchondroses in normal Chinese Han children aged 1-6 years, and to analyze the changing law of the atlantoaxial cartilage union with the growth and development of age and its influence on the atlantoaxial ossification in children. METHODS:A retrospective collection of CT imaging of 160 cases of normal cervical spine in children aged 1 to 6 years old was conducted. The cases were divided into six age groups, with each group representing a one-year age range. Measure the morphological anatomical indicators and anatomical positional indicators of the atlantoaxial synchondroses. Record and statistically analyze the measurements of each indicator. RESULTS:Measurements were taken on various parameters of the atlantoaxial synchondroses. TD, SD, height, area, and perimeter all gradually decreased among the groups. Distance between bilateral atlantal anterolateral synchondroses increased gradually from Group A to Group F, while the angle formed along the long axis in the cross-section showed a decreasing trend. Distance between the axoid dentolateral synchondroses and between the neurocentral synchondroses increased gradually from Group A to Group F, with the angle value in the cross-section showing a gradual decrease, and distance from the odontoid apex increasing from Group A to Group F. CONCLUSIONS:The atlantoaxial synchondroses gradually decrease in size with age, and ossification levels increase with age, with faster ossification occurring during a 1-2 years-old period. The anterolateral synchondroses, dentolateral synchondroses, and neurocentral synchondroses all gradually ossify towards the lateral direction with increasing age.

Background Spinal injury in children usually occurs in the cervical spine region. Anterior fixation of the lower cervical spine has been applied in treating pediatric cervical spine injury and disease due to its stable and firm mechanical properties. This study performed finite element analysis and comparison of four different anterior cervical internal fixation systems for children to explore more standard methods of anterior cervical internal fixation in children and seek more effective and safe treatment for children's cervical spine diseases. Methods A finite element model of 6-year-old children with lower cervical spine C4/5 discectomy was established, and the self-designed lower cervical spine anterior locking internal fixation system ACBLP and the children's anterior cervical internal fixation system ACOP, ACVLP, and ACSLP plate screws were fixed and loaded on the model. 27.42 N·m torque load was applied to each internal fixation model under six working conditions of anteflexion, backward flexion, left flexion, right flexion, left rotation, and right rotation, to simulate the movement of the cervical spine. The activity and stress distribution cloud diagram of each finite element model was obtained to explore the optimal method of anterior cervical fixation in children. Results In the four internal fixation models of ACOP, ACVLP, ACSLP, and ACBLP, the mobility of the C4/5 segment showed a decreasing relationship, and the mobility of adjacent segments increased significantly. In the Mises stress cloud diagram of the cervical spine of the four models, the vertebral body and accessories of the ACBLP model born the least stress, followed by ACSLP. The steel plate and screws in the ACVLP internal fixation model were the most stressed. The stress of the internal fixation system (plate/screw) in all models increased in the order of ACBLP, ACSLP, ACVLP, and ACOP. Conclusions ACBLP internal fixation system had obvious advantages in anterior internal fixation of the lower cervical spine in children, C4/5 had the smallest degree of movement, relative displacement was minimal, and the stress on the centrum and pedicle was the least, while the stress on the plate screw was relatively the smallest.

OBJECTIVE: To investigate the role and mechanism of the CD36/FAK/mTORC1 pathway in expressing inflammatory cytokines induced by lipopolysaccharide (LPS) in human mammary epithelial cells (MCF-10A). METHODS: Cells were infected with Escherichia coli using LPS, and the expression of CD36, activation of the FAK/mTORC1 pathway and secretion of inflammatory cytokines were measured. The cell membrane receptors CD36 and TLR4 were subsequently blocked with anti-CD36 and anti-TLR4, and the activation of the CD36/mTORC1 pathway was assessed. The expression of inflammatory cytokines and the activation of the FAK/mTORC1 pathway in LPS-treated cells were evaluated after FAK signal inhibition using TAE226, a specific chemical inhibitor of FAK. The expression of inflammatory cytokines and the activation of the mTORC1 pathway in cells treated with or without LPS were also evaluated after mTORC1 signal inhibition using RNAi. RESULTS: Western blot revealed that CD36 expression was significantly elevated at the mRNA and protein levels after treatment with LPS (p<0.05), and the activation of the FAK/mTORC1 pathway and related transcription factors was notably increased (p<0.05). ELISA showed an increase in the number of inflammatory cytokines TNF-alpha and IL-6 (p<0.05). The levels of phosphorylated FAK, S6 and 4EBP1 in LPS-stimulated cells were significantly attenuated (p<0.05) when CD36 was blocked compared to the levels in the control group. Further, the levels of phosphorylated FAK, S6, 4EBP1 and STAT1 decreased significantly when CD36 and TLR4 were blocked compared to the levels in the control group. TAE226 remarkably inhibited the activation of the FAK/mTORC1 pathway and the expression of inflammatory cytokines induced by LPS stimulation (p<0.05). The RNAi method was used to alter the expression of the key component of mTORC1, Raptor. The results were consistent with previous findings in Rapamycin-treated cells, in which the mTORC1 pathway was weakened, and the levels of TNF-alpha and IL-6 decreased. CONCLUSION: CD36 is a co-receptor for LPS and binds to mTORC1 and FAK to form the CD36/FAK/ mTORC1 pathway.

BACKGROUND:Microscopic structures of the ossification centres of the odontoid process were studied from the micro-computed tomography (CT) images of the axis, and the potential influence of the ossification centres with different microscopic structures on odontoid process fractures was analysed.MATERIALS AND METHODS:Eighteen odontoid process specimens were randomly collected and scanned by micro-CT. The obtained images were then input into the software for further observation and measurement. Incomplete absorption of the ossification centres in the base was observed, along with the anatomic structure of the regions with incomplete ossification and structural parameters of the trabecular bones.RESULTS:The microscopic structures of the trabecular bones in the ossification centres in the base of the odontoid process could be clearly visualised from the micro-CT images. Among the 18 odontoid process specimens, 11 specimens were found with incomplete absorption of the ossification centres in the axis, the prevalence reaching up to 61%. Regions with incomplete ossification varied in size and morphology, and their three-dimensional morphology was predominantly oval. Of all structural parameters examined for the trabecular bones, there were only significant differences in the degree of anisotropy between the regions with incomplete absorption of ossification centres and the average vertebral trabecular bones (p < 0.05).CONCLUSIONS:Incomplete absorption of the ossification centres in the base of the odontoid process is a relatively prevalent condition. The cavitation effect of the trabecular bones may be the primary cause for odontoid process fractures.

Background: Based on standard computed tomography (CT) and micro-CT scan axis images, our study aims to analyse the incidence of variation of non-fusion ossification centre in the base of the odontoid and its anatomical structure characteristics, to compare ossification centre images and analyse the possible features of the ossification centre that can influence adult odontoid fractures. Materials and methods: Fifty cases were selected for standard cervical CT of the normal axis bone (second cervical) anatomy to calculate the incidence of variation of the non-fusion ossification centre in the base of the odontoid and the indexes of associated anatomical structure. In addition, five dry bone samples with the odontoid were chosen for micro-CT to analyse the clear anatomic structure of the trabecular bone in the ossification centre. Results: Incidence of variation of non-fusion ossification centre in the base of the odontoid was 28%. In the non-ossification group, the mean sagittal diameter of the base of odontoid (SDBO, mm) was 7.64 ± 1.29 mm, the mean transverse diameter of the base of odontoid (TDBO, mm) was 7.14 ± 1.55 mm, and the SDBO:TDBO ratio was 1.1 ± 0.22. In the ossification group, the mean SDBO was 7.7 ± 1.15 mm, the mean TDBO was 7.38 ± 1.32 mm, and the SDBO:TDBO ratio was 1.07 ± 0.21. There was no significant difference in the associated indexes between the ossification and non-ossification groups (p > 0.05). Micro-CT revealed the micro-structure of trabecular bone in the ossification centre and the close relationship between the trabecular bone and the odontoid. One existing non-ossification centre in the base of the odontoid was found in the five odontoid images. The trabecular bone indexes chosen in the target area of the ossification centre were weaker than those in other areas. Conclusions: The variation rate of the non-fusion ossification centre in the base of the odontoid is relatively high and may be an important factor in the aetiology of type II and III odontoid fractures.

BACKGROUND:This study aims to investigate the morphological characteristics and developmental patterns of the vertebral arch pedicle (VAP) in the lower cervical vertebrae of children, and to subsequently help guide the implantation of the pedicle screw.MATERIALS AND METHODS:The cervical vertebral multi-slice computed tomography (MSCT) data of 60 paediatric patients aged 4-12 years were collected and grouped. A reconstructed 3-dimensional model measured the following: pedicle width (PW), pedicle height (PH), pedicle osseous channel (POCL), pedicle transverse angle (PTA, namely the E angle), and pedicle sagittal angle (PTA, namely the F angle).RESULTS:We calculated the ratio of PW/PH (I value) to assess the statistical difference between age groups and segments. The PW, PH, POCL, and E angles exhibited an overall increasing trend with increasing age. The PW, PH, and POCL of each vertebra in group C showed statically significant differences compared to groups A and B (p < 0.05). The PW of different vertebral sequences in each group showed a gradually increasing trend. The intervertebral F angle among different groups showed the biggest difference, a change from positive values to negative values gradually, among which the negative value of C7's F angle was the largest. The I value exhibited an overall decreasing trend with increasing age.CONCLUSIONS:The morphological characteristics and development of the different pedicle segments exhibited obvious patterns. In the lower cervical vertebrae of children over 7 years of age, the vertebrae had the feasibility for the implantation of pedicle screws.