The contribution of preoperative balanced halo-pelvic traction to severe rigid spinal deformity correction.

PURPOSE: The aim of this study was to assess the clinical efficacy of balanced halo-pelvic traction (HPT) and evaluate its contribution to the correction surgery in treating adult severe rigid spinal deformity. METHODS: One hundred and eight adult patients with severe rigid spinal deformity who underwent preoperative HPT and correction surgery were reviewed. The main coronal curve, segmental kyphotic angle, coronal balance (CB), sagittal balance (SVA), and the length of spine were measured before HPT, after HPT, post-operatively, and at final follow-up. The HPT contribution rates to deformity correction were calculated. RESULTS: The pre-HPT main coronal curve was 103.4 ± 10.6°, improved to 61.0 ± 13.4° after traction and further improved to 44.2 ± 10.2° after surgical correction, and maintained at 50.3 ± 9.9° at final follow-up. CB started at 4.2 ± 4.8 cm, improved to 2.1 ± 2.5 cm after HPT, 0.8 ± 1.2 cm after operation, and 0.7 ± 0.9 cm at final follow-up. The pre-HPT sagittal segmental kyphotic angle was 67.3 ± 17.7°, was then improved to 42.2 ± 27.5° after traction and further improved to 34.9 ± 10.2° after surgery, and maintained at 35.4 ± 10.4° at final follow-up. The length of spine improved from 35.9 ± 5.9 to 42.6 ± 6.0 cm via HPT, reached up to 45.0 ± 6.0 cm after operation, and maintained at 44.3 ± 5.2 cm at final follow-up. CONCLUSION: HPT is effective for the treatment of severe rigid spinal deformity. Balanced HPT can dramatically improve coronal and sagittal deformity as well as spinal length before corrective surgery.

Design of All-Dielectric Metasurface-Based Subtractive Color Filter by Artificial Neural Network.

Structural colors produced by light manipulating at subwavelength dimensions have been widely studied. In this work, a metasurface-based subtractive color filter (SCF) is demonstrated. The color display of the SCF is confirmed by finding the complementary color of colors filtered by SCF within the color wheel. In addition, two artificial neural network (ANN) models are utilized to accelerate the metasurface forward prediction, and the long short-term memory (LSTM) shows much better performance than traditional multilayer perceptron (MLP). Meanwhile, we train an inverse ANN model established with LSTM to recover the optimal geometric parameter combinations of the meta-atoms. With the variation of the geometric parameters of meta-atoms, versatile color displays of structural colors are realized. The metasurface we propose exhibits good performance of transmissive-type structural color in visible range. The work provides a method for high-efficiency geometric parameter prediction, and paves the way to nanostructure-based color design for display and anticounterfeiting applications.

Posterior Approach With Osteotomized Debridement Versus Combined Anterior and Posterior Approach in Treating Thoracolumbar Tuberculosis: A Retrospective Cohort Study.

STUDY DESIGN: Retrospective cohort. OBJECTIVES: To compare outcomes of posterior osteotomized debridement (OD) with combined anterior and posterior approach (AP) in treating thoracolumbar tuberculosis (TB). METHODS: This study reviewed 178 patients who were diagnosed as active thoracolumbar TB and surgically treated in our center. One hundred and two patients underwent posterior OD, interbody fusion with titanium mesh cage (TMC), and instrumentation (group A). Seventy-six patients underwent one-stage posterior instrumentation, anterior debridement, and interbody fusion with TMC (group B). Patients' clinical outcomes were compared between the 2 groups. RESULTS: Erythrocyte sedimentation rate and C-reactive protein in all patients returned to normal levels within 3 months after surgery, and no recurrence occurred during the follow-up. Compared with AP approach, OD surgery was less invasive and with a lower cost (¥ 70 581 ± 17 645 vs ¥ 87 600 ± 27 328; P < .05). Patients treated by OD showed more significant improvements in Visual Analog Scale (VAS) and Oswestry Disability Index (ODI) than those treated by AP approach 3 months postoperatively (VAS: 3.0 ± .7 vs 3.7 ± .9; ODI: 14.7 ± 4.4 vs 20.6 ± 4.6). Two groups showed similar postoperative kyphosis correction and final follow-up correction loss (P = .361 and P = .162, respectively). The OD method had a lower complication rate than AP approach (9.8% [10/102] vs 35.5% [27/76]; P < .05). CONCLUSIONS: Posterior OD is effective in treating active thoracolumbar TB. Compared with traditional AP approach, OD surgery has less surgical invasiveness, lower complication rate, and shorter fusion time.

Long short-term memory neural network for directly inverse design of nanofin metasurface.

In this Letter, the neural network long short-term memory (LSTM) is used to quickly and accurately predict the polarization sensitivity of a nanofin metasurface. In the forward prediction, we construct a deep neural network (DNN) with the same structure for comparison with LSTM. The test results show that LSTM has a higher accuracy and better robustness than DNN in similar cases. In the inverse design, we directly build an LSTM to reverse the design similar to the forward prediction network. By inputting the extinction ratio value in 8-12 µm, the inverse network can directly provide the unit cell geometry of the nanofin metasurface. Compared with other methods used to inverse design photonic structures using deep learning, our method is more direct because no other networks are introduced.

Global Spinal Realignment After Osteotomized Debridement in Active Lumbar Spinal Tuberculosis: Correlation with Patient-Reported Outcomes.

OBJECTIVE: Osteotomized debridement (OD) has been proved to be highly effective in treating active thoracolumbar tuberculosis (TB); however, no research has investigated how OD affects spinal alignment. The goal of this study was to explore the global alignment compensatory mechanism after lumbar OD, as well as the correlation between spinopelvic parameters and patient-reported outcomes (PROs). METHODS: Sixty-two patients with active lumbar spinal TB who underwent OD surgery were included. Spinopelvic parameters (C2-7 Cobb angle [C2-7 CA], sagittal vertical axis [SVA], proximal thoracic kyphosis, thoracic kyphosis, lumbar lordosis [LL], sacral slope [SS], pelvic tilt [PT], pelvic incidence [PI], spinosacral angle, and PI minus LL [PI-LL]) and PROs (Oswestry Disability Index [ODI] and Visual Analog Scale [VAS] score) were reviewed. The correlation between spinopelvic realignment and improved PROs was evaluated. RESULTS: Compared with preoperative measurements, C2-7 CA, proximal thoracic kyphosis, thoracic kyphosis, LL, SS, and spinosacral angle significantly increased after OD, whereas SVA, PT, and PI-LL significantly decreased. ODI and VAS score significantly improved postoperatively. The improvement of VAS was observed to be correlated with variations of C2-7 CA, SVA, LL, and PI-LL. The improvement of ODI was found to be correlated with variations of SVA, LL, and PI-LL. The multiple stepwise regression analysis showed that LL was an independent predictor for ODI and VAS score. CONCLUSIONS: The whole spine and pelvis are involved in realignment after lumbar spinal OD, which is closely related to PROs. More attention should be drawn to restoring an appropriate LL in lumbar TB surgery.

Two-Level Pedicle Subtraction Osteotomy in Lateral Position for an Ankylosing Spondylitis Patient With Severe Thoracolumbar Kyphosis and Hip Flexion Contracture: A Case Report.

BACKGROUND AND IMPORTANCE: Spinal osteotomy and total hip replacement (THR) are the most common surgical interventions for ankylosing spondylitis (AS). It is recommended that patients with AS with severe thoracolumbar kyphotic deformity (TLKD) and flexed hips receive spinal osteotomy before THR to reduce the risk of hip prosthesis dislocation after THR. Standardly, spinal osteotomy is performed in the prone position; however, it is impractical to place patients with AS with kyphosis and closed hips in a prone position. In this report, we present an AS case with severe TLKD and closed hips who underwent spinal osteotomy in a lateral position first, then THR in the second stage. CLINICAL PRESENTATION: The patient with AS was a 40-year-old woamn with severe TLKD and a closed hip. Back pain, difficulty walking, and gaze loss are the chief complaints. In consideration of the infeasibility of adopting the prone position, the patient was placed in a lateral position and underwent 2-level pedicle subtraction osteotomy at L1 and L3 with a long instrumentation from T10 to S1 at the first stage. Then, THR was performed at the second stage. The patient achieved pain relief, horizontal gaze, and nearly normal ambulation after spinal deformity correction and THR. After 2-year follow-up, the spinal alignment remains good and hip function was satisfactory. DISCUSSION: The sequence of spinal osteotomy and THR performed for AS patients with TLKD and hip flexion contracture remains inconclusive. According to previous studies, patients treated with THR under a sagittal malaligned spine may require revision of the acetabular component to accommodate to the re-orientated acetabula resulting from the subsequent spinal osteotomy and realignment. Thus, we believe it is more reasonable to perform spinal osteotomy first. For osteotomy in lateral position, one of the key points is that the operation table should be tilted away from the surgeon side at a certain angle. Another point is that contralateral cancellous bone should be removed as much as possible when performing osteotomy at the side of vertebral away from the table. The satisfactory outcomes of this case revealed the feasibility of osteotomy in a lateral position for such severe AS with closed hip. CONCLUSION: Performing double-level spinal osteotomy in a lateral position first could be an alternative for patients with AS who cannot be placed in the prone position because of the severe deformity of the spine and hips.

Osteotomized debridement versus curetted debridement in posterior approach in treating thoracolumbar tuberculosis: a comparative study.

PURPOSE: This study aimed to compare osteotomized debridement (OD) with traditional curetted debridement (CD) in treating thoracolumbar tuberculosis (TB). METHODS: A total of 188 patients were diagnosed with active thoracolumbar TB and underwent one-stage posterior surgery at our institution. Of the 188 patients, 85 patients were treated with OD, and 103 patients were treated with traditional CD. The patient information, laboratory results, imaging findings, and clinical effectiveness were, respectively, compared between the two groups. RESULTS: Group OD consumed less operation time and blood loss than group CD (P < 0.05 for both values). No significant difference in hospitalization time was found between the two groups (P > 0.05). The values of C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) in both groups returned to the normal range within one month postoperatively. All patients had significant improvement in visual analog scale (VAS) and oswestry disability index (ODI) postoperatively. The mean fusion time in group OD was shorter than that in group CD (P < 0.05). There was no statistically significant difference in preoperative kyphotic angle between the two groups (P > 0.05), but group OD showed less correction loss than group CD at the final follow-up (P < 0.05). The rate of recurrence and surgery-related complications in group OD was lower than group CD. CONCLUSIONS: Posterior OD, reconstruction with titanium mesh cages (TMCs), and instrumentation is feasible and effective in treating thoracolumbar TB. Compared with the traditional CD, OD can achieve radical lesion removal, more effective kyphosis correction, lower recurrence rate, and fewer complications.

Case Report of Angular Post-Tuberculotic Kyphosis Corrected Through Pedicle Subtraction Osteotomy Above C7.

BACKGROUND AND IMPORTANCE: Angular cervical kyphosis and its association with syringomyelia were rarely described. Correcting this kind of deformity from the front is extremely difficult or even impossible. Meanwhile, no study has made a report about correcting angular cervical kyphosis through pedicle subtraction osteotomy (PSO) above C7 because of the special anatomy of the vertebral artery. This is the first case of cervical deformity correction through PSO above C7. CLINICAL PRESENTATION: We present the case of a 52-yr-old man who previously underwent debridement, decompression, and skull traction for cervical tuberculosis at age 6 yr. The sequelae of right-hand weakness occurred after surgery, and cervical kyphosis formed gradually. The patient recently started to complain of a severe neck pain. X-rays showed a cervical sagittal malalignment due to the angular kyphosis. Computed tomography scans revealed a fused angular kyphosis at C6-7, and MRI showed a long syringomyelia distal to the kyphosis. The definite diagnosis of the patient was post-tuberculotic cervical angular kyphosis, and because of the extremely narrow surgery corridor from the front, we decided to perform the surgery in a posterior approach. Hence, the patient was treated with the PSO with a long-segment pedicle screw fixation from C3 to T5 and received satisfactory angular kyphosis correction. CONCLUSION: PSO above C7 to correct angular cervical kyphosis is feasible and reasonable when there is no other better solution, and it can achieve a satisfactory kyphotic deformity correction.

Ball Tip Technique for S2AI Screw Placement in Sacropelvic Fixation: A Comparative Study with Conventional Freehand Technique.

OBJECTIVE: To evaluate the efficiency of the ball tip technique for S2AI screw placement and introduce this technique. METHODS: Sixty-three patients who underwent pelvic fixation with S2AI screws were retrospectively reviewed. They were 29 males and 34 females with an average age of 59.6 ± 12.5 years. Among these patients, 35 patients (14 males and 21 females with an average age of 58.8 ± 11.3 years) received ball tip technique and 28 patients (15 males and 13 females with an average age of 63.7 ± 12.6 years) received conventional freehand technique. Ball tip technique was used in ball tip technique group. After a pedicle probe just penetrated the sacroiliac joint, a ball-tipped probe consisting of a ball shaped metal tip with a flexible shaft was malleted to make a guide track within ilium. This ball-tipped probe could bend automatically away from the cortex and forward through the cancellous bone when the tip met the cortical lamina of ilium, which can avoid penetration. After repeating the procedures, a guide hole was gradually formed. S2AI screw was inserted along the guide hole after tapping. In the conventional freehand group, S2AI screw was placed according to the conventional method. Postoperative computed tomography (CT) was used to assess the accuracy of screws. The time cost of screw insertion and screw-related complications were recorded. Independent t-test was used to compare the time cost between ball tip group and conventional freehand group. A chi-square test was used to compare the accuracies of the ball tip group with the conventional group. RESULTS: There were 35 patients (70 S2AI screws) in ball tip group and 28 patients (56 S2AI screws) in conventional freehand group. No screw-related complication occurred in all patients. Time costs were 9.8 ± 4.5 mins in ball tip group and 20.2.0 + 8.6 mins in conventional freehand group, respectively (P < 0.05). Four screws penetrated iliac cortex in the ball tip group vs 10 screws in conventional freehand group (5.7% vs 17.9%) (P < 0.05). CONCLUSIONS: The ball tip technique enhances the accuracy of screw placement and has less time cost compared with conventional freehand technique.

LncRNA FOXP4-AS1 Promotes Progression of Ewing Sarcoma and Is Associated With Immune Infiltrates.

Ewing sarcoma (ES) is a highly malignant primary bone tumor with poor prognosis. Studies have shown that abnormal expression of lncRNA influences the prognosis of tumor patients. Herein, we established that FOXP4-AS1 was up-regulated in ES and this correlated with poor prognosis. Further analysis illustrated that FOXP4-AS1 down-regulation repression growth, migration, along with invasion of ES. On the contrary, up-regulation of FOXP4-AS1 promoted the growth, migration, as well as invasion of ES. To explore the mechanism of FOXP4-AS1, Spearman correlation analysis was carried out to determine genes that were remarkably linked to FOXP4-AS1 expression. The potential functions and pathways involving FOXP4-AS1 were identified by GO analysis, Hallmark gene set enrichment analysis, GSEA, and GSVA. The subcellular fractionation results illustrated that FOXP4-AS1 was primarily located in the cytoplasm of ES cells. Then a ceRNA network of FOXP4-AS1 was constructed. Analysis of the ceRNA network and GSEA yielded two candidate mRNAs for FOXP4-AS1. Results of the combined survival analysis led us to speculate that FOXP4-AS1 may affect the expression of TMPO by sponging miR-298, thereby regulating the malignant phenotype of ES. Finally, we found that FOXP4-AS1 may modulates the tumor immune microenvironment in an extracellular vesicle-mediated manner. In summary, FOXP4-AS1 correlates with poor prognosis of ES. It promotes the growth, migration, as well as invasion of ES cells and may modulate the tumor immune microenvironment.

Precise Control of Green to Blue Emission of Halide Perovskite Nanocrystals Using Terbium Chloride as Chlorine Source.

CsPbClxBr3-x nanocrystals were prepared by ligand-assisted deposition at room temperature, and their wavelength was accurately adjusted by doping TbCl3. The synthesized nanocrystals were monoclinic and the morphology was almost unchanged after doping. The fluorescence emission of CsPbClxBr3-x nanocrystals was easily controlled from green to blue by adjusting the amount of TbCl3, which realizes the continuous and accurate spectral regulation in the range of green to blue. This method provides a new scheme for fast anion exchange of all-inorganic perovskite nanocrystals in an open environment at room temperature.

Structural transitions of centromeric chromatin regulate the cell cycle-dependent recruitment of CENP-N.

Specific recognition of centromere-specific histone variant CENP-A-containing chromatin by CENP-N is an essential process in the assembly of the kinetochore complex at centromeres prior to mammalian cell division. However, the mechanisms of CENP-N recruitment to centromeres/kinetochores remain unknown. Here, we show that a CENP-A-specific RG loop (Arg80/Gly81) plays an essential and dual regulatory role in this process. The RG loop assists the formation of a compact "ladder-like" structure of CENP-A chromatin, concealing the loop and thus impairing its role in recruiting CENP-N. Upon G1/S-phase transition, however, centromeric chromatin switches from the compact to an open state, enabling the now exposed RG loop to recruit CENP-N prior to cell division. Our results provide the first insights into the mechanisms by which the recruitment of CENP-N is regulated by the structural transitions between compaction and relaxation of centromeric chromatin during the cell cycle.

Dynamic phosphorylation of CENP-A at Ser68 orchestrates its cell-cycle-dependent deposition at centromeres.

The H3 histone variant CENP-A is an epigenetic marker critical for the centromere identity and function. However, the precise regulation of the spatiotemporal deposition and propagation of CENP-A at centromeres during the cell cycle is still poorly understood. Here, we show that CENP-A is phosphorylated at Ser68 during early mitosis by Cdk1. Our results demonstrate that phosphorylation of Ser68 eliminates the binding of CENP-A to the assembly factor HJURP, thus preventing the premature loading of CENP-A to the centromere prior to mitotic exit. Because Cdk1 activity is at its minimum at the mitotic exit, the ratio of Cdk1/PP1α activity changes in favor of Ser68 dephosphorylation, thus making CENP-A available for centromeric deposition by HJURP. Thus, we reveal that dynamic phosphorylation of CENP-A Ser68 orchestrates the spatiotemporal assembly of newly synthesized CENP-A at active centromeres during the cell cycle.

Repression of recA induction by RecX is independent of the RecA protein in Deinococcus radiodurans.

Besides inhibiting RecA activity at the protein level, Deinococcus radiodurans RecX can suppress RecA induction at the transcriptional level. The regulation of RecX on recA induction is independent of RecA activity, and its N terminus is involved in this process.