BACKGROUND:Due to the importance of pedicle adjacent structures, once the screw replacement appears a deviation, adjacent structures may be damaged, leading to extremely serious consequences. Although the security of screw placement in thoracic vertebral pedicle-rib complex is significantly greater than that of pedicle screws, the mechanics of the pedicle-rib complex at different cross-sectional areas of the screw are rarely reported.
OBJECTIVE:To observe mechanical property of different cross-sectional area screws in the middle and upper thoracic vertebral pedicle-rib complex.
METHODS:Five specimens of adult cadaveric thoracic spine (T 1-T 10 ) and adjacent rib segment (50-60 mm long) were used. The bone density of specimens was measured using difunctional bone density testing machine, and osteoporotic vertebral body was excluded. The position of the screws was detected with CT images. The maximal withdrawal force of the pedicle screw was measured with biomechanical force test machine.
RESULTS AND CONCLUSION:Thirty-eight specimens at normal bone density were implanted with 25 screws (5.5 mm), 25 screws (6.0 mm) and 26 screws (6.5 mm). Because the pedicle screws destroyed the pedicle-rib complex and perforated the vertebral body, we final y obtained the withdrawal force of 68 screws. The axial withdrawal force of pedicle screws at different diameters was (812.36±147.22) N, (868.64±160.48) N and (946.48±157.58) N, respectively. There were significant differences between the 5.5 mm screws and the 6.5 mm screws (P<0.05). Experimental findings indicate that, the pedicle screws (diameter>5.5 mm) are suitable in the middle and upper thoracic vertebral pedicle-rib complex due to strong internal fixation and clinical requirement.

BACKGROUND:Establishment of high-quality finite element model is an important basis of biomechanical analysis. The reports on three-dimensional finite element model of complete adolescent idiopathic scoliosis are less. OBJECTIVE:To set up three-dimensional finite element model of PUMCIId1 adolescent idiopathic scoliosis for building ideal digitization platform for further biomechanical study. METHODS:A 14-year-old female patient with PUMCIId1 adolescent idiopathic scoliosis was included as volunteer for the current study. CT images obtained from CT transverse scanning from T 1 to sacrococcyx were imported into Mimics 16.0 software to form qualified three-dimensional geometric model, including thoracic cage, which was further delivered to Geomagic Studio 11.0 software to build three-dimensional finite element model by a series of modules and optimization of cleaning. The geometric model was imported to ANSYS 14.0 software to build complete three-dimensional finite element adolescent idiopathic scoliosis model by adding ligaments, setting unit type, and defining material properties. RESULTS AND CONCLUSION:A complete three-dimensional finite element model of PUMCIId1 adolescent idiopathic scoliosis was built successful y, consisting of 522 887 tetrahedron elements and 730 rod elements, a total of 523 617 units and 159 008 nodes. Three-dimensional finite element model of PUMCIId1 adolescent idiopathic scoliosis was lifelike, and can be used as the reliable digital model for further biomechanical analysis.

BACKGROUND:Studies have shown that posterior orthopedic internal fixation and anterior orthopedic internal fixation al can get good clinical outcomes for treatment of adult idiopathic scoliosis, however, it has not been reported on what kind of methods could achieve a better clinical outcome for treatment of Lenke3 type adult idiopathic scoliosis, have less risk of pedicle screws breakage and more reliable long-term efficacy. OBJECTIVE:To establish the Lenke 3 type adult idiopathic scoliosis finite element model and thoracic screw guide target 3D model using finite element analysis software, so as to provide scientific basis for biomechanical analysis and scientific pedicle screw implantation. METHODS:The CT scan image from T 1 to sacrum of one 28 years old volunteer with Lenke 3 type adult idiopathic scoliosis was imported into Mimics 16.0 software by Dicom form. Integral idiopathic scoliosis three dimensional model was established by geometry clear technology. Nail guide target of thoracic vertebra was established on vertebral model by design module in Mimics 16.0 software. The point cloud form of three dimensional model was imported into Geomagic Studio 11.0 software. Series of image processing of model were conducted. At last, three dimensional model was imported into ANSYS 14.0 finite element analysis software in order to build finite element model with biological properties. RESULTS AND CONCLUSION:Complete Lenke 3 type adult idiopathic scoliosis three dimensional finite element model was established successful y. It concluded 440 975 tetrahedron units and 580 bar units, total y 441 555 units and 1 077 318 nodes. Total y 12 nail guide target models of thoracic vertebra were established, including 4 682 tetrahedron units and 7 390 nodes. Lenke 3 type adult idiopathic scoliosis three dimensional finite element model and nail guide target of thoracic vertebral model with a realistic appearance were established successful y in this experiment. These results confirm that Lenke 3 type adult idiopathic scoliosis three dimensional finite element model provides scientific basis for further biomechanical experiments. Meanwhile, the construction of nail guide target model of thoracic vertebra provide a new scientific method for thoracic pedicle screw placement.

BACKGROUND:Thoracic lumbar segment is prone to spinal tuberculosis, caseous necrosis tissue, dead bone compression of spinal cord and nerve root may cause neurological symptoms, and the majority of them is accompanied with mild and moderate spinal kyphosis deformity. Surgical treatment of spinal tuberculosis has been frequently reported in recent years, the commonly used treatment includes lesion clearance, bone graft fusion and internal fixation. OBJECTIVE:To investigate the principle of choosing different internal fixation treatment for thoracolumbar spinal tuberculosis. METHODS:42 patients with thoracolumbar spinal tuberculosis were involved in this study from January 2001 to December 2011. Al patients suffered from waist and back pains, with the disease course range of 1 month to 7 years. Four cases showed neurological deficit before surgery. According to the Frankel classification, 1 case was graded as Frankel C and 3 cases as Frankel D. The preoperative average Cobb angle of kyphosis was 27° (range 12°-45°). The internal fixation approaches were chosen according to the tuberculose focus and vertebral fracture extent. Thoraco-abdominal approach for thoracolumbar spine via diaphragm with the removal of 11 rib and(or) 12 rib was performed for al patients. Among these protocols, 25 cases underwent anterior focal debridement and bone grafting. 17 cases had anterior focal debridement and posterior pedicle screw internal fixation (one-stage surgery in 7 cases and second-stage surgery in 10 cases). Al patients received anti-tuberculosis chemotherapy before and after operation. 36 cases used rib and 6 cases used iliac bone as bone graft. Al patients were fol owed up from 17 months to 9 years. The correction of spinal deformity, spinal stability and spinal functional recovery were observed. RESULTS AND CONCLUSION:30 patients were fol owed up after operations and the back pains disappeared. X-ray examination showed that, al patients were fixed wel without no loosening and rupture, and achieved bony fusion (the mean time were 5.4 months). No tuberculosis recurred. Four cases complicated with spinal cord injury were E grade according to the Frankel classification. The Cobb angle was 0-26° (mean 14°) at 12 months after operation. On the premise of standard anti-tuberculosis chemotherapy, various internal fixation methods can be determined according to general conditions of patients and tuberculose focus site.

Objective The aim of current study is to determine the effect and mechanism of thymic stromal lymphopoietin on apoptosis of mouse nucleus pulposus cells by investigating the apoptotic activity and variation of intracellular phosphorylated protein kinase B (p-Akt),X-linkedinhibitor of apoptosis protein (XIAP),cysteinyl aspartate specific proteinase-3 (caspase-3),with the treatment of thymic stromal lymphopoietin.Methods Mouse lumbar nucleus pulposus cells were cultured and identified under a fluorescence microscope.Second or third passage cells maintained in monolayers were used for the following experiments.The groups were divided randomly into normal group,TNF-α treated group,TSLP treated group,TSLP+LY94002 treated group and TSLP+Embelin treated group.As a control,normal group was treated with PBS.TNF-α treated group was treated with 500 ng/ml TNF-αt as a positive control.TSLP treated group was treated with 10 ng/ml rhTSLP.TSLP+LY94002 treated group and TSLP+ Embelin treated group were treated with 10 ng/ml TSLP with the pretreatment of different pathway inhibitors for 30 ain in different corresponding experiments,for which 10 μ mol LY294002 or 50 LY294002 responding experimentsreatment of different pathway inhibitors formouse nucleus pulposus cells was detected by FACS.The expression levels of the intracellular p-Akt,XIAP,caspase-3 were investigated by Western blot analysis.Results As the culture cell type Ⅱ collagen staining was positive observed by fluorescence microscopy,we confirmed that the cuhured cells were nucleus pulposus cells.In comparison with negative control,the levels of p-Akt,XIAP in TSLP treated group were elevated (t=9.510,P=0.001;t=8.851,P=0.001).Thecaspase-3 activity were slightly enhanced and the rate of cells apoptosis was no significance.Compared with TSLP treated group,downregulated level of pAkt and XIAPand upregulatedcaspase-3 activity in TSLP+LY294002 treated group were observed (t=8.798,P=0.001;t=7.032,P=0.002;t=5.908,P=0.004).Upregulated caspase-3 activity were also observed in TSLP+ Embelin treated group (t=7.990,P=0.001).Furthermore,significant increased apoptotic cell rate was observed in TSLP+LY294002 or TSLP+Embelin treated groups (t=21.268,P=0.001;t=21.279,P=0.001).Conclusion TSLP may have a potential anti-apoptotic effect on mouse NP cells via upregulating XIAP in PI3K/Akt signaling pathway to restrain the activation of caspase-3.

Objective:To explore the clinical efficacy of posterior short-segment internal fixation for the treatment of brucella spondylitis (BS).Methods:The medical records of 34 patients with BS admitted from January 2014 to June 2019 were retrospectively analyzed. There were 22 males and 12 females; the age was 52.3±10.6 years (range 35-72 years). On the basis of standardized use of antibacterial drugs, the lumbar spine posterior short-segment internal fixation was used. Twenty-nine cases underwent simple internal fixation, and posterolateral bone graft fusion, while 5 cases underwent primary debridement, autologous bone grafting and interbody fusion. Monitor erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), and test tube agglutination test (SAT) were used to assess inflammation control. Imaging examinations of patients before operation, 1 month after operation, 3 months after operation, 6 months after operation, 1 year after operation to the last follow-up were analyzed to evaluate the condition of intervertebral fusion. The clinical efficacy evaluation was based on the pain visual analog scale (VAS), Japanese Orthopaedic Association (JOA) score, modified MacNab grading, and American Spinal Injury Association (ASIA) grading, as well as surgery-related complications.Results:The operation time of 34 patients was 104.64±16.72 min (range 65-145 min), the average hospital stay was 16.49±7.41 days (range 7-38 d), and the average postoperative follow-up time was 20.2 months (range 12-34 months). At the last follow-up, the ESR and CRP fell to the normal range, and the SAT was negative. At 3 months postoperatively, 11 cases (32.35%) reached Bridwell fusion criteria of grade II, 23 cases (67.65%) of grade III; 3 cases (8.82%) of grade I fusion at 6 months after surgery, 31 cases reached grade II fusion (91.18%); all reached grade I fusion at the last follow-up. After the operation, the symptoms of the waist or lower extremities were significantly relieved. The VAS score was 6.3±1.4 before the operation, 4.1±1.2 at 1 month after the operation, 2.7±1.4 at 3 months after the operation, 1.6±1.0 at 6 months after the operation, and 1.2±0.8 at the last follow-up. The JOA score before surgery was 13.8±2.4, 1 month after surgery 17.6±2.6, 3 months after surgery 21.7±3.1, 6 months after operation 4.9±2.7, and at the last follow-up 25.7±1.8. Compared with the preoperative time nodes of the above indicators, the differences were statistically significant. At the last follow-up, of the 12 patients (2 cases of grade C, 10 cases of grade D) with preoperative neurological dysfunction, 2 cases recovered from grade C to grade D, and 10 cases recovered from grade D to E; the excellent and good rate of modified MacNab grading reached 97.06% (33/34). No extradural hematoma, nerve damage, cerebrospinal fluid leakage and other surgical complications occurred. Only 1 case had wound infection complication, and the prognosis was good after active treatment. There were no recurrences during the follow-up period.Conclusion:On the basis of standardized antimicrobial treatment, posterior lumbar short-segment internal fixation is a safe and effective method for the treatment of BS, and good clinical effects can be obtained.

Objective:To construct an artificial intelligence-assisted diagnosis system to recognize the characteristics of Helicobacter pylori ( HP) infection under endoscopy, and evaluate its performance in real clinical cases. Methods:A total of 1 033 cases who underwent 13C-urea breath test and gastroscopy in the Digestive Endoscopy Center of Renmin Hospital of Wuhan University from January 2020 to March 2021 were collected retrospectively. Patients with positive results of 13C-urea breath test (which were defined as HP infertion) were assigned to the case group ( n=485), and those with negative results to the control group ( n=548). Gastroscopic images of various mucosal features indicating HP positive and negative, as well as the gastroscopic images of HP positive and negative cases were randomly assigned to the training set, validation set and test set with at 8∶1∶1. An artificial intelligence-assisted diagnosis system for identifying HP infection was developed based on convolutional neural network (CNN) and long short-term memory network (LSTM). In the system, CNN can identify and extract mucosal features of endoscopic images of each patient, generate feature vectors, and then LSTM receives feature vectors to comprehensively judge HP infection status. The diagnostic performance of the system was evaluated by sensitivity, specificity, accuracy and area under receiver operating characteristic curve (AUC). Results:The diagnostic accuracy of this system for nodularity, atrophy, intestinal metaplasia, xanthoma, diffuse redness + spotty redness, mucosal swelling + enlarged fold + sticky mucus and HP negative features was 87.5% (14/16), 74.1% (83/112), 90.0% (45/50), 88.0% (22/25), 63.3% (38/60), 80.1% (238/297) and 85.7% (36 /42), respectively. The sensitivity, specificity, accuracy and AUC of the system for predicting HP infection was 89.6% (43/48), 61.8% (34/55), 74.8% (77/103), and 0.757, respectively. The diagnostic accuracy of the system was equivalent to that of endoscopist in diagnosing HP infection under white light (74.8% VS 72.1%, χ2=0.246, P=0.620). Conclusion:The system developed in this study shows noteworthy ability in evaluating HP status, and can be used to assist endoscopists to diagnose HP infection.