Morphometric Trajectory Analysis for Occipital Condyle Screws.

OBJECTIVES: Occipitocervical fusion (OCF) is an effective treatment for instability of occipitocervical junction (OCJ). The occipital condyle screw serves as a novel surgical technique for occipitocervical fixation. However, the intraoperative procedures for the occipital condyle screw technique have relied on surgeons' experience, so the pool of surgeons who are able to perform this surgery safely is limited. The present study aims to evaluate the feasibility and safety of the occipital condyle screw technique using human cadavers and to provide image anatomy for clinical application basis. METHODS: The scientific study comprised 10 fresh-frozen cadaveric specimens from the anatomy department of Qingdao University. Placement of the occipital condyle screws (3.5 mm diameter and 20.0 mm length) was performed in the 10 fresh-frozen cadaveric specimens with intact occipitocervical junctions, respectively. Occipitocervical CT was performed for all specimens and the DICOM data was obtained. Occipitocervical CT three-dimensional (3D) reconstruction was performed for the cadavers. Morphometric analysis was performed on the bilateral occipitocervical junction of 10 cadaveric specimens based on the 3D reconstruction CT images. Detailed morphometric measurements of the 20 occipital condyles screws were conducted including the average length of the screw trajectory, inside and upper tilting angles of screws, distance to the hypoglossal canal, and to the medial wall of occipital condyle. RESULTS: Placement of the occipital condyle screws into the 20 occipital condyles of the 10 cadaveric specimens was performed successfully and the trajectory of implantation was satisfactory according to 3D CT reconstruction images, respectively. There was no obvious injury to the spinal cord, nerve root, and vertebral artery. The length of the bilateral screw trajectory was, respectively, 20.96 ± 0.91 mm (left) and 20.59 ± 0.77 mm (right) (t = 1.306, P > 0.05). The upper tilting angle of bilateral screws was, respectively, 11.24° ± 0.74° (left) and 11.11° ± 0.64° (right) (t = 0.681, P > 0.05). The inside tilting angle of bilateral screws was, respectively, 31.00° ± 1.32° (left) and 30.85° ± 1.27° (right) (t = 0.307, P > 0.05). The screw's distance to the bilateral hypoglossal canal was, respectively, 4.84 ± 0.54 mm (left) and 4.70 ± 0.54 mm (right) (t = 0.685, P > 0.05). The screw's distance to the medial wall of the bilateral occipital condyle was, respectively, 5.13 ± 0.77 mm (left) and 5.04 ± 0.71 mm (right) (t = 0.384, P > 0.05). CONCLUSION: The occipital condyle screw technique can serve as a feasible and safe treatment for instability of the occipitocervical junction with meticulous preoperative planning of the screw entry point and direction based on individual differences. Morphometric trajectory analysis is also an effective way to evaluate the surgical procedure.

Neuroprotective effects of atomoxetine against traumatic spinal cord injury in rats.

OBJECTIVES: Spinal cord injury (SCI) often causes serious and irreversible neurological deficit leading to disability or impairment of normal physical activity. Atomoxetine, a selective norepinephrine transporter (NET) inhibitor has gained much attention in the field of the neurodevelopmental disorder, but its effect on SCI has not been evaluated. The present study has been undertaken to investigate the neuroprotective effects of atomoxetine. MATERIALS AND METHODS: Administration of atomoxetine 20 mg/kg IP was compared with methylprednisolone (MP) 30 mg/kg IP in traumatic spinal cord injured Wistar rats. Tissue samples were evaluated for apoptosis, inflammation, and oxidative stress, along with histopathological examination and neurological evaluation. RESULTS: There was no significant difference in the caspase-3 activity between the control and the sham groups or between the MP and the atomoxetine groups (P=0.811). The administration of atomoxetine significantly reduced tissue tumour necrosis factor alpha (TNF-α), and nitric oxide (NO) levels compared to the trauma group (P<0.001). Treatment with atomoxetine also decreased the tissue myeloperoxidase (MPO) activity (P=0.026) and increased the tissue superoxide dismutase (SOD) activity compared to the trauma group (P=0.001 and P=0.004, respectively). Histopathological examination showed less degenerated neurons in the atomoxetine group compared to trauma group. CONCLUSION: This is the first experimental evidence showing meaningful neuroprotective effects of atomoxetine over SCI through anti-apoptotic, anti-inflammatory, and antioxidant effects by reducing lipid peroxidation, which was confirmed by biochemical, histopathological and the functional evaluation.

MiR-125a Rs12976445 Polymorphism is Associated with the Apoptosis Status of Nucleus Pulposus Cells and the Risk of Intervertebral Disc Degeneration.

BACKGROUND: Spinal degenerative diseases are a major health problem and social burden worldwide. Intervertebral disc degeneration (IDD) is the pathological basis of spinal degenerative diseases and is characterized by loss of nucleus pulposus cells due to excessive apoptosis caused by various factors. MicroRNAs (miRNAs) have been reported to be functionally involved in the control of apoptosis. METHODS: computational analysis and luciferase assay were used to identify the target of miR-125a, and cell culture, transfection were used to confirm such relationship. Sequencing was used to determine the genotype of each participant. RESULTS: We confirmed the previous report that the presence of the minor allele (T) of rs12976445 polymorphism significantly downregulated the expression level of miR-125a in nucleus pulposus cells, leading to less efficient inhibition of its target gene. We also validated TP53INP1 as a target of miR-125a in nucleus pulposus cells using a dual luciferase reporter system, and the transfection of miR-125a significantly reduced the expression of TP53INP1. The expression level of TP53INP1 was significantly lower in nucleus pulposus cells genotyped as CT or TT than in those genotyped as CC, and the apoptosis rate was consistently lower in the CC group than in the nucleus pulposus cells collected from individuals carrying at least one minor allele of rs12976445 polymorphism. To study the association between rs12976445 polymorphism and the risk of IDD, we enrolled 242 patients diagnosed with IDD and 278 normal controls, and significant differences were noted regarding the genotype distribution of rs12976445 between the IDD and the control groups (OR = 2.69, 95% C.I. = 1.88-3.83, p < 0.0001). In summary, rs12976445 polymorphism is significantly associated with the risk of IDD in the Chinese population. CONCLUSION: The present study indicated that miR-125a is a promising potential target for patients with IDD in clinical practice.

Single-stage combined anterior retropharyngeal and posterior approach for the resection and reconstruction of C2 metastatic tumors: A case report.

This study reports the case of a 44-year-old male who had experienced severe neck pain for one month and was diagnosed with a metastatic tumor of the left C2 vertebral body and the left transverse process. The tumor was distributed to layers A-D and sectors 3-7 according to the Weinstein-Boriani-Biagini classification, and was in Category IV according to the Harrington classification system. A conventional posterior cervical approach was used to resect the left transverse process and part of the tumor in a piecemeal fashion, and spinal instrumentation was also performed. Gelfoam and absorbable hemostatic gauze were placed ventrally to the left vertebral artery and the left C3 nerve root over the tumor bed to prevent their accidental injury in the subsequent anterior approach. A high anterior retropharyngeal approach was then used to resect the tumorous C2 vertebral body by corpectomy and to perform anterior reconstruction. Six months after the surgery, the patient remained pain free. Therefore, C2 metastatic tumor resection and spinal reconstruction can be fulfilled by a single-stage combined high anterior retropharyngeal and posterior approach.