Qingjie Kong

Evaluating the Rotation Correction of the Main Thoracic Curve in Severe Adolescent Idiopathic Scoliosis: Bending and Traction vs. Fulcrum – A Preliminary Report

Background Flexibility evaluation methods were only used to assess the changes of coronal Cobb angle in patients with adolescent idiopathic scoliosis (AIS). Little attention was attached to the vertebral rotation in these methods. Material/Method 21 patients with severe adolescent idiopathic scoliosis were enrolled in this study. Coronal flexibility and rotation correction were compared on the supine bending, traction and fulcrum bending radiographs. The apical vertebral body rib ratio (AVB-R), and Perdriolle rotation angles were used to measure the rotation of the main thoracic curve. Statistical analysis was performed with one-way Analysis of Variance(ANOVA). Correlations between postoperative AVB-R and AVB-R in supine bending, traction and fulcrum bending radiographs were assessed utilizing the Linear Regression. Results There were trends towards increased coronal flexibility in fulcrum bending versus traction versus supine bending, but there were no significant differences due to the limited sample size. And all were significantly lower than postoperative correction. The correction of AVB-R at traction and supine bending radiographs were significantly better than fulcrum bending, however, all were significantly lower than postoperative correction. Correction of Perdriolle rotation angle at traction radiograph was best among these methods. A univariant linear regression analysis showed a strong linear correlation between the postoperative AVB-R and the AVB-R in the traction radiograph. Conclusions As to patients with severe AIS, the coronal plane flexibility evaluated at the fulcrum bending radiograph is superior to that at the traction radiograph. This may be explained by the measurement errors induced by the better derotation capacity at the traction radiograph. Rotation correction evaluated at the traction radiograph proves better than the fulcrum bending radiographs, showing a linear correlation with the postoperative correction.

Segmental characteristics of main thoracic curves in patients with severe adolescent idiopathic scoliosis

OBJECTIVE Segmental flexibility in adolescent idiopathic scoliosis is crucial for the development of nonfusion and osteotomy technology. However, only global curve flexibility has been assessed in previous studies. Knowledge about segmental characteristics is absent. METHODS Twenty patients with severe adolescent idiopathic scoliosis were enrolled in the present study. The vertebral and disc wedge angles were measured, and the segmental flexibility index was assessed by the correction rate of disc wedging on the traction film. Least significant difference analysis was used to compare the distribution of the variable. The patients were divided into 2 groups according to the stiffness of the global curves, and their relative wedging was compared. RESULTS Vertebral wedging decreased from the apex toward the end. The apical and adjacent vertebrae accounted for 67.44% ± 8.05% of the total vertebral wedging deformities. Disc wedging significantly decreased upward and downward from the apex. Disc wedging demonstrated no significant differences between U1 (first above the apex) and U2 or L1 (first below the apex) and L2, and these 4 discs accounted for 75.47% ± 9.25% of the total disc wedging deformities. The levels close to the apical discs (U2 and L2) had the smallest extent of limited correctability. Segment disc flexibility showed a W-shaped distribution. The disc angle in the non-stiff group was significantly larger than the vertebral angle (40.13° ± 4.67° vs. 26.62° ± 6.99°; P < 0.001); however, similar results were not noted in the stiff group. CONCLUSIONS Significant apical tethering in both vertebral body and disc wedging occurred, and the relative wedging changed significantly according to the rigidity of the main thoracic curves.

The clinical outcomes of primary and revision untethering surgery in patients with tethered cord syndrome and spinal bifida

BACKGROUND Tethered cord syndrome (TCS) is an increasingly recognized clinical condition, with untethering surgery considered the classically effective treatment. Yet, as evidence has aggregated, the surgical outcomes of untethering remain controversial. This study aimed to systematically evaluate the clinical outcomes in patients who underwent primary or revision untethering. METHODS This retrospective study was conducted at the Department of Spine Surgery of Changzheng Hospital between January and December 2016. Patients with TCS who underwent untethering surgery were recruited for the study. Information collected included demographic data, main clinical manifestations, and outcomes after untethering surgery. RESULTS A total of 112 patients (60 males and 52 females) were included in this study, with mean follow-up of 13.7 years. The surgical outcomes of the primary untethering varied among symptoms, with remission rates of 30.0% for pain, 24.4% for paresthesia, 18.6% for motor deficit, 12.6% for bladder dysfunction, and 21.2% for bowel dysfunction. Moreover, 23.3%-40.2% of patients suffered deterioration after surgery during the follow-up period. Twenty-eight patients underwent revision untethering surgery. In these patients, the remission rate decreased by 5.6%-16.7% compared with the primary operation. Moreover, most patients (58.8%-70.6%) experienced no benefits after revision surgery. CONCLUSIONS With a possible high risk of recurrence, further exploration of the indications and timing of the untethering surgery is needed. Conservative treatment and omnidirectional care might be a better choice for patients with retethering with recurrent symptoms.

Low-Intensity Pulsed Ultrasound Treatment Accelerates Angiogenesis by Activating YAP/TAZ in Human Umbilical Vein Endothelial Cells

As a non-invasive method, low-intensity pulsed ultrasound (LIPUS) can accelerate fracture healing. The mechanisms responsible for the enhanced fracture healing need to be studied further. Activation of YAP/TAZ, key mediators of the Hippo signaling pathway, could promote angiogenesis and vascular remodeling. The purpose of this study was to determine whether LIPUS treatment can activate YAP/TAZ. Human umbilical vein endothelial cells (HUVEC) were used. After LIPUS treatment, Western blot and immunofluorescence staining were used for YAP/TAZ activation. Small interfering RNA (siRNA) of YAP and short hairpin LATS1/2 (shLATS1/2) were used to check whether there is cross-talk with the Hippo pathway. The phosphorylated YAP (p-127 and p-397) protein increased more than 3-fold 0.5 h after LIPUS treatment (p < 0.05). TAZ protein increased 3.0-, 2.0- and 1.5-fold 0.5, 6 and 12 h after LIPUS treatment. We found that LIPUS treatment activates YAP/TAZ, which is translocated into the cell nucleus to activate target genes. This process can be inactivated by siYAP and activated by shLATS1/2. The cross-talk with the Hippo pathway can initiate angiogenesis so as to accelerate fracture healing by LIPUS.

Protective effect of epigenetic silencing of CyclinD1 against spinal cord injury using bone marrow-derived mesenchymal stem cells in rats

This study focuses on the protective effect of epigenetic silencing of CyclinD1 against spinal cord injury (SCI) using bone marrow‐derived mesenchymal stem cells (BMSCs) in rats. Eighty‐eight adult female Wistar rats were randomly assigned into the sham group, the control group, the si‐CyclinD1 + BMSCs group and the BMSCs group. CyclinD1 protein and mRNA expressions after siRNA transfection were detected by Western blotting and qRT‐PCR. The siRNA‐CyclinD1 BMSCs were transplanted into rats in the si‐CyclinD1 + BMSCs group using stereotaxic method 6 hr after SCI. Hindlimb locomotor performance was determined using inclined plane test and Basso‐Beattie‐Bresnahan (BBB) locomotor rating scale. Expressions of glial fibrillary acidic protein (GFAP) and nerve growth factor (NGF) were detected by immunohistochemistry. Inclined plane and BBB scores in the control, si‐CyclinD1 + BMSCs, and BMSCs groups were significantly lower than the sham group, but these scores were evidently decreased in the control group and increased in the si‐CyclinD1 + BMSCs group compared with the BMSCs group. The repair degree of spinal cord tissues of rats in the si‐CyclinD1 + BMSCs group was obvious than the BMSCs group. GFAP and NGF protein expressions were markedly decreased in the control, si‐CyclinD1 + BMSCs and BMSCs groups when compared with the sham group. GFAP‐ and NGF‐positive cells were significantly increased in the si‐CyclinD1 + BMSCs group while decreased in the control group. Our study provides evidence that epigenetic silencing of CyclinD1 using BMSCs might accelerate the repair of SCI in rats.

The bridge crane technique for the treatment of the severe thoracic ossification of the ligamentum flavum with myelopathy.

PurposeThis study aims to investigate the clinical effect and complications of a novel technique named bridge crane for the treatment of the severe thoracic ossification of the ligamentum flavum (TOLF) with myelopathy.MethodA patient diagnosed as TOLF (T9–T11) was treated with the bridge crane technique and the outcomes were reported. The main surgical procedures include installation of pedicle screws, rods and transverse connectors; preparation of stay prolene sutures passing through the laminae-OLF complex (LOC); en bloc isolation of the LOC; tightening of the sutures to achieve posterior suspension of the LOC; and fixation of the LOC to the transverse connectors. The modified Japanese Orthopaedic Association (mJOA) scale was studied. The pre- and postoperative radiological parameters and surgical complications were also investigated.ResultsPostoperative CT and MRI showed a sufficient decompression of spinal cord by the technique of bridge crane. The ratio of spinal canal encroachment improved significantly. At the final follow-up assessment, no specific complications were identified. Imaging information suggested that the bone graft was fused and the “bridge” was in good position. The mJOA score was 9 with a recovery rate of 75% at the final follow-up.ConclusionsThe technique of bridge crane is feasible and may be relatively safe and effective for the treatment of severe TOLF with myelopathy. However, further studies with large-scale cases and control groups are required to reveal the generalizability and safety of the bridge crane technique in the future.Graphical abstractThese slides can be retrieved under Electronic Supplementary Material.

Effects of MicroRNA-494 on Astrocyte Proliferation and Synaptic Remodeling in the Spinal Cord of a Rat Model of Chronic Compressive Spinal Cord Injury by Regulating the Nogo/Ngr Signaling Pathway

Background/Aims: Chronic compression of the spinal cord causes the loss of motor neurons in the anterior horn, but the precise and extensive mechanism for the loss is not completely determined. Therefore, this study aims to explore the role of microRNA-494 (miR-494) in the proliferation of astrocytes and in the synaptic remodeling in the spinal cord of a rat model of chronic spinal cord injury (SCI) by regulating the Nogo/NgR signaling pathway. Methods: A rat model of chronic, compressive SCI was established, and the spinal cord state, blood supply changes, and astrocyte apoptosis were observed. Reverse transcription quantitative polymerase chain reaction (RT-qPCR) and Western blotting were used to detect expression of miR-494 and the Nogo/NgR signaling pathway-related genes. Fluorescence in situ hybridization (FISH) was used for detecting miR-494 expression and distribution. Results: Higher miR-494 expression was accompanied by the inhibition of astrocyte proliferation and synaptic remodeling. In addition, CDK6 could be regulated by miR-494 and was shown to be one of the target genes of miR-494. Positive expression of miR-494 detected by FISH was consistent with the results from RT-qPCR that miR-494 could downregulate CDK6 gene expression. Moreover, the direct miR-494 target CDK6 plays important inhibitory roles in chronic SCI by suppressing the Nogo/ NgR signaling pathway. Conclusions: The results demonstrated that miR-494 inhibition can promote astrocyte proliferation and synaptic remodeling by suppressing the Nogo/NgR signaling pathway in a rat model of chronic SCI.