Objectives:To analyze the risk factors for prolonged length of stay(LOS)after lesion removal and bone graft fusion internal fixation in patients with spinal tuberculosis,and to develop and validate a predictive model.Methods:The clinical data of 152 patients with spinal tuberculosis who underwent lesion removal and bone grafting and fusion internal fixation at Honghui Hospital affiliated to Xi'an Jiaotong Univer-sity from February 2016 to December 2020 were retrospectively analyzed.The patients were divided into the prolonged LOS(PLOS)group and normal LOS(NLOS)group according to whether their postoperative LOS ex-ceeded the postoperative LOS of the 75th percentile of the overall study cohort.Univariate analyses were per-formed for gender,age,hypertension,diabetes,paraplegia,anticoagulation history,tuberculosis resistance,pre-operative anti-tuberculosis time,blood transfusion,surgical site,surgical approach,number of fused vertebrae,operative time,intraoperative blood loss(IBL),postoperative complications,blood transfusion cost,hospital cost,C-reactive protein(CRP),erythrocyte sedimentation rate(ESR),albumin(ALB),blood routine,and coagulation function in both groups.Based on Lasso regression,the risk factors significantly associated with postoperative LOS prolongation in spinal tuberculosis were selected and incorporated into a multivariate logistic regression analysis,and thereby a prediction model was established based on the results of multivariate logistic regres-sion analysis.The model was visualized by plotting a nomogram as a means of predicting the probability of risk for prolongation of LOS after spinal tuberculosis surgery.Internal validation of the model was performed using extended Bootstrap,where receiver operating characteristic(ROC)curves,calibration curves and decision curve analysis(DCA)were plotted to verify the discrimination,accuracy and clinical applicability.Results:The 152 patients enrolled in the study had a median LOS of 10d,and the 75%LOS was 14d.There were 96 patients in the PLOS group and 56 in the NLOS group.Univariate analysis showed that the differences in age,hypertension,diabetes,anticoagulation history,tuberculosis resistance,preoperative anti-tuberculosis time,surgical site,surgical approach,surgical time,IBL,postoperative complications,CRP,ESR,preoperative ALB,blood routine,and coagulation function were not statistically significant between the two groups(P＞0.05),while the differences in gender,paraplegia,blood transfusion,number of fused vertebrae,blood transfusion cost,and hospitalization cost were statistically significant(P＜0.05).The operative time,IBL,preoperative Hb,and preop-erative ALB were divided according to the Yoden index of ROC as the dividing point,and the cut-off value of operative time was 198(min),the cut-off value of IBL was 1000(mL),the cut-off value of preoperative Hb was 118(g/L),and the cut-off value of preoperative ALB was 38.8(g/L).Through Lasso regression model,the risk factors closely related to the prolongation of LOS after spinal tuberculosis were female,blood transfusion,the number of fused vertebrae≥3,operative time≥198min and IBL≥1000mL,preoperative Hb＜118g/L and preoperative ALB＜38.8g/L.Multivariate logistic regression analysis showed that female,number of fused ver-tebrae≥3,operative time≥198min and IBL≥1000mL were the risk factors for postoperative LOS prolongation in patients with spinal tuberculosis(P＜0.05).A visual nomogram model for logistic regression was constructed,and the predictors included female,number of fused vertebrae,operative time,and IBL.A Bootstrap self-sampling of 1,000 times was performed to complete the internal validation of the model,with a C-index value of 0.882 and an area under the curve(AUC)of ROC of 0.884(95%CI:0.782 to 0.985).The calibration curve showed that the apparent curve of the model fitted well with the curve after deviation correction.The DCA curve showed that the threshold range of 0.2 to 0.9 had the greatest clinical benefit.Conclusions:Female,number of fused vertebrae≥3,operative time≥198min and IBL≥1000mL are the main risk factors for pro-longed LOS after lesion removal and bone graft fusion with internal fixation in patients with spinal tuberculo-sis,and the predictive model based on the above risk factors can help physicians to make clinical decisions and optimize the perioperative management.

Objective:To compare the efficacy of percutaneous vertebroplasty (PVP) under enhanced regional and conventional anesthesia for multisegmental acute symptomatic osteoporotic thoracolumbar fractures (m-ASOTLF).Methods:A retrospective cohort study was conducted to analyze the data of 91 patients with m-ASOTLF who were admitted to Honghui Hospital of Xi′an Jiaotong University from January 2021 to December 2022, including 36 males and 55 females, aged 55-80 years [(67.4±7.3)years]. According to American Society of Anesthesiologists (ASA) classification system, 18 patients were classified as grade I, 52 grade II, and 21 grade III. Injured segments included T 6-T 10 in 23 patients, T 11-L 2 in 47 and L 3-L 5 in 21. All the patients were treated with PVP, among whom 45 were given enhanced regional anesthesia (enhanced anesthesia group) and 46 regional conventional anesthesia (conventional anesthesia group). The following indicators were compared between the two groups: the operation time, intraoperative bleeding, intraoperative heart rate, intraoperative mean arterial pressure (MAP), number of intraoperative fluoroscopies, and total amount of bone cement injected; the visual analogue scale (VAS) and Oswestry dysfunction index (ODI) before surgery, at 1 day, 1 month after surgery and at the last follow-up; the mini-mental state examination (MMSE) before surgery, at 1, 6, and 12 hours after surgery; the anterior vertebrae height (AVH), middle vertebrae height (MVH), and vertebral kyphosis angle (VKA) before and at 1 day after surgery; the incidence of complications such as bone cement leakage. Results:All the patients were followed up for 12-20 months [(15.8±2.6)months]. There were no significant differences between the two groups in the operation time, intraoperative bleeding, intraoperative heart rate, intraoperative MAP, number of intraoperative fluoroscopies or total amount of bone cement injected ( P>0.05). No significant differences were found between the two groups in VAS or ODI before surgery and at the last follow-up ( P>0.05). The VAS scores in the enhanced anesthesia group were (2.5±0.4)points and (1.8±0.3)points at 1 day and 1 month postoperatively respectively, which were both lower than (3.5±0.4)points and (2.0±0.5)points in the conventional anesthesia group ( P<0.01). The ODI values in the enhanced anesthesia group were 39.8±3.3 and 26.5±5.0 at 1 day and 1 month postoperatively respectively, which were both lower than 43.8±7.5 and 30.3±6.4 in the conventional anesthesia group ( P<0.01). The VAS and ODI at all postoperative time points decreased in both groups compared with those before surgery, with significant differences among those at all postoperative time points ( P<0.05). There was no significant difference between the two groups in the MMSE scores before, at 1, 6, and 12 hours after surgery ( P>0.05). The MMSE scores at 1 and 6 hours postoperatively were lower than that preoperatively in both groups ( P<0.05), and it was increased at 6 hours compared with that at 1 hour postoperatively ( P<0.05). There was no significant difference between the MMSE scores at 12 hours postoperatively and preoperatively in both groups ( P>0.05). The differences between the two groups in AVH, MVH, or VKA preoperatively were not statistically significant ( P>0.05). The AVH and MVH at 1 day postoperatively in the enhanced anesthesia group were (22.4±4.2)mm and (22.7±3.7)mm respectively, which were both higher than those in the conventional anesthesia group [(19.3±3.7)mm and (20.1±6.3)mm] ( P<0.05 or 0.01); the VKA at 1 day postoperatively in the enhanced anesthesia group was (13.9±3.7)°, which was lower than that in the conventional anesthesia group (15.8±4.1)° ( P<0.05). The AVH, MVH, and VKA in both groups were all improved at 1 day postoperatively compared with those preoperatively ( P<0.05). The incidence of bone cement leakage in the enhanced anesthesia group was 6.7% (3/45), which was lower than 21.7% (10/46) in the conventional anesthesia group ( P<0.05). Conclusion:Compared with conventional regional anesthesia, PVP under enhanced regional anesthesia for m-ASOTLF has more advantages in early postoperative pain relief, improvement of spinal function, restoration of vertebral height and reduction of bone cement leakage.

Cervical spinal cord injury without fracture-dislocation (CSCIWFD) in adults is a condition in which the cervical spinal cord is injured by an external force to the cervical spine, but the cervical spine itself is not fractured or dislocated on X-ray films or CT. Since CSCIWFD is caused by a second-strike injury to the body, with a compression formed by spinal cord edema and ligamentous hematoma, signs of neurological function impairment that may not appear until several days after the injury which often cause incomplete or complete paralysis, thus resulting in chronic pain and loss of work. Inadequate treatment in the early stages of injury can exacerbate delayed neurological deficits, seriously offecting the patients' quality of life and life expectancy. Currently, there are problems related to the diagnosis and treatment of CSCIWFD, such as the of clinical manifestations varying severity, complex mechanism of injury, high rates of missed diagnosis and misdiagnosis, and controversial treatment methods. Besides, standardized diagnostic and treatment regimens, multimodal diagnostic approach, and individualized treatment plans should be adopted to improve the diagnostic accuracy and therapeutic effects and maximize the prognosis of patients. In this regard, the authors discussed the clinical characteristics and key issues requiring urgent attention in the diagnosis and treatment of CSCIWFD to provide a reference for clinical diagnosis and treatment.

Objective:To purify H5N1 influenza virus concentrate prepared by MDCK cells with a new mixed-mode chromatography medium Capto Core700 and the traditional medium Sepharose 4FF, and to compare the separation and purification efficacy of the two media.Methods:Capto Core700 and Sepharose 4FF were used to purify inactivated H5N1 influenza virus concentrate. The morphology of virus particles in different samples was then observed under a transmission electron microscope. Single radial immunodiffusion (SRID), Folin-Phenol (Lowry) method, double-antibody sandwich ELISA and qPCR were used to detect hemagglutinin, total protein, host cell protein (HCP) and host cell DNA (HCD) before and after purification. The recovery rate of virus antigen and the removal rate of impurities were calculated. The immunogenicity of the viruses purified with different media was analyzed using animal experiments. Difference in the purification efficacy of the two chromatography media was analyzed by t-test. Results:H5N1 influenza viruses purified by Capto Core700 or Sepharose 4FF showed the typical influenza virus morphology under transmission electron microscope. There was no significant difference in the recovery rate of hemagglutinin between the two chromatography media ( P>0.05), but compared with Sepharose 4FF, Capto Core700 had a higher removal rate of impurities (total protein, HCP, HCD) and the difference was statistically significant ( P<0.05). Animal experiments showed that the viruses purified by the two chromatography media had good immunogenicity. Conclusions:Compared with Sepharose 4FF chromatography medium, Capto Core700 could more effectively remove process-related impurities such as HCP, HCD and total protein without affecting the recovery rate of viral antigen. This study provided reference for the development of purification technology in the production of H5N1 influenza virus vaccine in MDCK cells.

The incidence of osteoporotic vertebral compression fractures (OVCF) is increasing year by year. OVCF is manifested by thoracolumbar back pain, kyphosis and limitation of motion, which severely reduces the quality of life and life expectancy of the patients. It is often caused by minor violence with an insidious onset, and has a high rate of missed diagnoses on routine examination. Currently, percutaneous vertebroplasty (PVP) and percutaneous kyphoplasty (PKP) are effective treatments for OVCF, but postoperative complications such as cement leakage and vertebral re-fracture occur often. Digital orthopedic technology is an emerging interdisciplinary discipline that combines computer digital technology with orthopedic clinics. As a new orthopedic clinical technology, digital orthopedic technology is pushing the boundaries of spinal surgery research and clinical application due to its advantages in individualization, precision, and minimally invasiveness, and is currently at a rapid development stage with high endurance and high throughput. To this end, the authors outlined the current application of digital orthopedic technology in OVCF, so as to provide a reference for achieving rapid and accurate diagnosis of OVCF and formulating reasonable treatment plans.

Objective:To test and evaluate the reliability and clinical effectiveness of osteoporotic thoracolumbar fracture (OTLF) scoring and classification system.Methods:A multicenter retrospective case series study was conducted to analyze the clinical data of 530 OTLF patients admitted to 8 hospitals including Honghui Hospital Affiliated to Xi'an Jiaotong University from January 2021 to June 2022. There were 212 males and 318 females, aged 55-90 years [(72.6±10.8)years]. There were 4 patients with grade C and 18 with grade D according to American Spinal Injury Association (ASIA) classification. According to the osteoporotic thoracolumbar injury classification and severity (OTLICS) score, all patients had an OTLICS score over 4 points and required surgical treatment. Among them, 410 patients had acute symptomatic OTLF (ASOTLF), including 24 patients with type I, 159 type IIA, 47 type IIB, 31 type IIC, 136 type IIIA, 8 type IIIB, 2 type IV (absence of neurological symptoms) and 3 type IV (presence of neurological symptoms), and 120 patients had chronic symptomatic OTLF (CSOTLF), including 62 patients with type I, 21 type II, 17 type III, 3 type IV (reducible under general anesthesia), 9 type IV (not reducible under general anesthesia), 1 type V (reducible under general anesthesia), 5 type V (presence of neurological symptoms), and 2 type V (not reducible under general anesthesia). Surgical procedures included percutaneous vertebroplasty (PVP), positional repositioning plus PVP, percutaneous kyphoplasty (PKP), posterior open reduction combined with bone graft fusion and bone cement augmented screw internal fixation, posterior open reduction combined with decompression, bone graft fusion and bone cement augmented screw internal fixation, and posterior open reduction combined with osteotomy and orthopedics, bone graft fusion and bone cement augmented screw internal fixation. A weighted Kappa was used to test the interobserver and intraobserver reliability of the OTLICS score, the ASOTLF classification, and the CSOTLF classification. The visual analog scale (VAS), Oswestry disability index (ODI), ASIA classification were compared before, at 1 month after surgery and at the last follow-up. Incidence of postoperative complications was observed.Results:The percentage of mean interobserver agreement for OTLICS staging was 93.4%, with a mean confidence Kappa value of 0.86, and the percentage of mean intraobserver agreement was 93.0%, with a mean confidence kappa value of 0.86. The percentage of mean interobserver agreement for ASOTLF staging was 94.2%, with a mean confidence Kappa value of 0.84, and the percentage of mean intraobserver agreement was 92.5%, with a mean confidence Kappa value of 0.83. The percentage of mean interobserver agreement for CSOTLF subtyping was 91.9%, with a mean confidence Kappa value of 0.80, and the percentage of mean intraobserver agreement was 91.3%, with a mean confidence Kappa value of 0.81. All the patients were followed up for 6-12 months [(9.0±2.1)months]. The VAS and ODI scores were significantly lower in patients with ASOTLF and CSOTLF classifications at 1 month after surgery and at the last follow-up than those before surgery (all P<0.05). The VAS scores in patients with ASOTLF types IIA, IIB, IIC, IIIA, and IV were significantly lower at the last follow-up than that at 1 month after surgery; the ODI scores in patients with ASOTLF types I, IIA, IIB, IIIA, IIIB and IV were significantly lower at the last follow-up than those at 1 month after surgery. The VAS scores in patients with CSOTLF types II, III, IV, and V were significantly lower at the last follow-up than those at 1 month after surgery, and the ODI scores in patients with all CSOTLF types were significantly lower at the last follow-up than those at 1 month after surgery (all P<0.05). Two patients with ASIA grade C recovered to grade D, and the rest recovered to grade E at the last follow-up ( P<0.01). No major vessel or nerve injury or internal fixation failure was found during follow-up. There were 18 patients with cement leakage, none of whom showed relevant clinical symptoms. There were 35 patients with new vertebral fractures, all of whom recovered well after symptomatic treatment. Conclusions:The OTLICS score, ASOTLF classification and CSOTLF classification have a high degree of reliability. Application of stepwise treatment for patients with different levels of injury according to the scoring and classification system can reduce pain, promote recovery of the spinal function, and reduce complications, which is of some significance in guiding the selection of clinical treatment.

Objective:To investigate the risk factors associated with the occurrence of proximal junctional kyphosis (PJK) after posterior long-segment internal fixation for type IV chronic symptomatic osteoporotic thoracolumbar fracture (CSOTLF) in the elderly.Methods:A case-control study was used to analyze the clinical data of 95 elderly patients with type IV CSOTLF treated in Honghui Hospital affiliated to Xi′an Jiaotong University from January 2013 to June 2018, including 32 males and 63 females, aged from 60 to 85 years［(67.4±6.5) years］. Injured segments were T 11 in 17 patients, T 12 in 37, L 1 in 30 and L 2 in 11. All patients were treated with posterior long-segment internal fixation and divided into PJK group ( n=30) and non-PJK group ( n=65) according to whether PJK occurred after surgery. Univariate analysis was performed for the correlation of the following indices with the incidence of postoperative PJK, including general information such as gender, age, body mass index (BMI), bone mineral density (BMD), history of smoking, cause of injury, comorbidities, injury segments, American Spinal Injury Association (ASIA) classification and time from injury to surgery, preoperative imaging data such as posterior junctional angle (PJA), sagittal vertical axis (SVA), pelvic incidence-lumbar lordosis difference (PI-LL), pelvic tilt (PT) and sacral slope (SS), basic surgical data such as posterior ligament complex (PLC) injury, location of upper instrumented vertebrae (UIV), location of lower instrumented vertebrae (LIV) and number of fixed segments. Multifactorial Logistic regression analysis was used to measure the independent risk factors associated with the occurrence of postoperative PJK. Results:Univariate analysis showed that the incidence of postoperative PJK was correlated with age, BMI, BMD, preoperative PJA, preoperative SVA, preoperative PI-LL, PLC injury, location of UIV, location of LIV and number of fixed segments (all P<0.05), rather than gender, history of smoking, cause of injury, comorbidities, injury segments, ASIA classification, time from injury to surgery, preoperative PT and preoperative SS (all P>0.05). Multifactorial Logistic regression analysis showed that age ≥70 years ( OR=32.28, 95% CI 3.83-272.29, P<0.01), BMI>28.0 kg/m 2 ( OR=7.88, 95% CI 1.63-37.99, P<0.01), BMD T value<-3.5 SD ( OR=20.84, 95% CI 2.36-183.93, P<0.01), preoperative PI-LL>20° ( OR=13.30, 95% CI 1.54-113.87, P<0.05) and PLC injury ( OR=13.98, 95% CI 1.37-142.34, P<0.05) were significantly associated with the occurrence of postoperative PJK. Conclusions:Age≥70 years, BMI>28 kg/m 2, BMD T value<-3.5 SD, preoperative PI-LL>20° and PLC injury are independent risk factors for the incidence of PJK after posterior long-segment internal fixation in elderly patients with type IV CSOTLF. Attention should be paid to soft tissue protection and sagittal balance restoration of the spine intraoperatively and weight control and anti-osteoporosis treatment postoperatively.

With the large use of vertebral augmentation in the treatment of osteoporotic thoracolumbar fracture (OTLF), the complication of cement leakage has become an increasing concern. Although most cement leakage has no obvious clinical symptoms, some patients still sustain serious complications such as vertebral fracture, pulmonary embolism and spinal nerve compression. Cement leakage is closely related to patients′ own factors, cement factors and perioperative related factors. To clarify the risk factors of cement leakage with implementation of preventive measures accordingly is of great guiding significance to improve the clinical efficacy and surgical safety. Therefore, the authors discuss bone cement leakage in aspects of the risk factors and preventive measures so as to provide a reference for reducing the incidence of cement leakage.

Objective:To compare the clinical efficacy of femoral neck system (FNS) and cannulated screw fixation in the treatment of femoral neck fracture in the young and middle-aged patients.Methods:A retrospective cohort study was conducted to analyze the clinical data of 76 young and middle-aged patients with femoral neck fracture admitted to Honghui Hospital Affiliated to Xi′an Jiaotong University from March 2018 to September 2020, including 45 males and 31 females, aged 23-63 years [(49.5±8.2)years]. Garden classification of the fracture was 25 patients with type II, 34 with type III and 17 with type IV. Pauwels classification of the fracture was 16 patients with type I, 31 with type II and 29 with type III. A total of 40 patients were treated with cannulated screw fixation (cannulated screw group) and 36 patients with FNS fixation (FNS group). Operation time, frequency of fluoroscopy, length of hospital stay, weight-bearing time and bone union time were compared between the two groups. Hip function was assessed by Harris hip score at 6, 12 months after operation. The incidence of postoperative complications was observed.Results:All patients were followed up for 12-20 months [(15.2±1.7)months]. The frequency of fluoroscopy [(13.4±1.9)times], weight-bearing time [(11.1±1.9)weeks] and bone union time [(13.8±1.6)weeks] in FNS group were lower or shorter than those in cannulated screw group [(18.2±2.6)times, (15.7±1.6)weeks, (14.6±1.6)weeks] (all P<0.05 or 0.01). There were no significant differences in operation time, length of hospital stay and Harris hip score at 6, 12 months after operation between the two groups (all P>0.05). No postoperative infection occurred in both groups. In cannulated screw group, there were 4 patients with femoral neck shortening, 3 with deep venous thrombosis, 2 with internal fixation loosening, 2 with nail withdrawal and 1 with fracture non-union, showing the incidence of complications of 30% (12/40). In FNS group, there was 2 patients with femoral neck shortening, 1 with deep vein thrombosis and 1 with internal fixation loosening, showing the incidence of complications of 11% (4/36) ( P<0.05). Conclusion:For femoral neck fracture in the young and middle-aged patients, both FNS and cannulated screw fixation can obtain satisfactory efficacy, but FNS has the advantages of decreased frequency of intraoperative fluoroscopy, early weight bearing, reduced time to bone union and low incidence of complications.

Objective:To compare the clinical effects between cannulated screwing and plating in combination with interlocking intramedullary nailing for the treatment of ipsilateral discontinuous fractures of the tibial shaft and plateau.Methods:A retrospective analysis was performed of the clinical data of 34 patients who had been treated for ipsilateral discontinuous fractures of the tibial shaft and plateau at Department of Orthopedics and Trauma, Honghui Hospital Affiliated to Xi′an Jiaotong University from January 2015 to January 2020. There were 17 males and 17 females, aged from 26 to 60 years (average, of 43.6 years). The left side was affected in 18 cases and the right side in 16. The patients were divided into 2 groups according to their internal fixation methods: a cannulated screw group of 16 cases treated with cannulated screwing and intramedullary nailing and a plate group of 18 cases treated with plating and intramedullary nailing. The 2 groups were compared in terms of operation time, intraoperative blood loss, incision length, tibial plateau collapse, consumables cost, hospital stay, fracture healing time, weight-bearing time, range of knee motion, reduction of tibial plateau fracture by Rasmussen radiology, Lysholm knee function score at the last follow-up and complications.Results:There was no significant difference in the preoperative general data between the 2 groups, showing the 2 groups were comparable ( P>0.05). All the 34 patients were followed up for 12 to 28 months (average, 17.4 months). There was no significant difference either in operation time, hospital stay, tibial plateau healing time, tibial fracture healing time, weight-bearing time or range of knee motion between the 2 groups ( P>0.05). In the cannulated screw group, the intraoperative blood loss [(89.4 ± 14.5) mL] and consumables cost [(2.0 ± 0.2) ten thousand yuan] were significantly less than those in the plate group [(120.8 ± 22.1) mL and (2.6 ± 0.4) ten thousand yuan], the incision length [(4.1 ± 0.8) cm] was significantly shorter than that in the plate group [(7.1 ± 0.9) cm], and the Lysholm knee function score at the last follow-up [(89.8 ± 4.5) points] was significantly lower than that in the plate group [(93.0 ± 4.2 points] (all P<0.05). The difference was statistically significant between the 2 groups in the quality of tibial plateau reduction ( P<0.05). The postoperative tibial plateau collapse in the plate group [0.5 (0, 2) mm] was insignificantly less than that in the cannulated screw group [1.0 (0, 2) mm] ( P>0.05). In the cannulated screw group, one tibial shaft fracture did not achieve union after operation and deep vein thrombosis occurred in 2 cases after operation; in the plate group, 2 cases suffered from delayed wound healing, one from delayed fracture healing, one from deep venous thrombosis of lower extremity, and one from knee discomfort which was relieved after removal of internal fixation. Conclusions:In the treatment of ipsilateral discontinuous fractures of tibial shaft and plateau, both cannulated screwing and plating in combination with interlocking intramedullary nailing can achieve good clinical effects. Although plating in combination with intramedullary nailing lead to more severe trauma and higher costs, it is conducive to improving the reduction quality of the tibial plateau and postoperative functional recovery of the knee joint.