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Osteosarcoma is the most common primary malignant tumor of bone derived from osteoblasts, which is a noteworthy threat to the health of children and adolescents. In this study, we found that MCM8 has significantly higher expression level in osteosarcoma tissues in comparison with normal tissues, which was also correlated with more advanced tumor grade and pathological stage. In agreement with the role of MCM proteins as indicators of cell proliferation, knockdown/overexpression of MCM8 inhibited/promoted osteosarcoma cell proliferation in vitro and tumor growth in vivo. Also, MCM8 knockdown/overexpression was also significantly associated with the promotion/inhibition of cell apoptosis and suppression/promotion of cell migration. More importantly, mechanistic study identified CTGF as a potential downstream target of MCM8, silencing of which could enhance the regulatory effects of MCM8 knockdown and alleviate the effects of MCM8 overexpression on osteosarcoma development. In summary, MCM8/CTGF axis was revealed as critical participant in the development and progression of osteosarcoma and MCM8 may be a promising therapeutic target for osteosarcoma treatment.

The transcription factor p300 is reportedly involved in age-associated human diseases, including intervertebral disc degeneration (IDD). In this study, we investigate the potential role and pathophysiological mechanism of p300 in IDD. Clinical tissue samples were collected from patients with lumbar disc herniation (LDH), in which the expression of p300, forkhead box O3 (FOXO3), and sirtuin 1 (Sirt1) was determined. Nucleus pulposus cells (NPCs) isolated from clinical degenerative intervertebral disc (IVD) tissues were introduced with oe-p300, oe-FOXO3, Wnt/β-catenin agonist 1, C646 (p300/CBP inhibitor), or si-p300 to explore the functional role of p300 in IDD and to characterize the relationship between p300 and the FOXO3/Sirt1/Wnt/β-catenin pathway. Also, we established a rat IDD model by inducing needle puncture injuries in the caudal IVDs for further verification of p300 functional role. We found that p300 was downregulated in the clinical tissues and NPCs of IDD. Overexpression of p300 promoted the proliferation and autophagy of NPCs while inhibiting cell apoptosis, which was associated with FOXO3 upregulation. p300 could increase the expression of FOXO3 by binding to the Sirt1 promoter, and thus, contributed to inactivation of the Wnt/β-catenin pathway. In vivo results further displayed that p300 slowed down the progression of IDD by disrupting the Wnt/β-catenin pathway through the FOXO3/Sirt1 axis. Taken together, we suggest that p300 can act to suppress IDD via a FOXO3-dependent mechanism, highlighting a potential novel target for treatment of IDD.

To evaluate the safety and efficacy of modified facet joint fusion (MFF) for the treatment of multilevel (three-level or more) lumbar spinal stenosis (LSS).In this retrospective study, 135 consecutive patients who underwent initial MFF for multilevel LSS were included. Clinical outcomes included fusion rate, change of visual analogue scale pain scores for low back pain (VAS-LBP) and leg pain (VAS-LP), Japanese Orthopedic Association scores (JOA), Oswestry Disability Index (ODI) and MacNab classification before and after MFF. The complications were also analyzed.The fusion rates were 46.7% (63/135) at 6-month and 89.6% (121/135) at 1-year. The mean VAS-LBP, VAS-LP, and ODI significantly decreased from 5.2 ± 0.6, 5.7 ± 0.8 and 65 ± 7.9 to 1.58 ± 0.4, 0.58 ± 0.3 and 20.8 ± 5.8, respectively (allMFF may be safe and efficient for multilevel LSS with high fusion rate and significant symptom relief, which is worthy of further study.

The present study aimed to develop nomograms to predict survival in patients with chondroblastic osteosarcoma (COS). An analysis was conducted of 320 cases of COS collected from the surveillance, epidemiology, and end results (SEER) database between 2004 and 2015. Independent prognostic factors were screened using univariate and multivariate Cox analyses. Subsequently, nomograms were established to predict the patients’ cancer-specific survival (CSS) and overall survival (OS) rates. The prediction accuracy and discriminative ability of the nomograms were examined using calibration curves and the concordance index (C-index). As revealed in the univariate and multivariate Cox regression analysis, age, tumor size, the primary site, the presence of metastasis, a history of having undergone surgery, and a history of having received radiotherapy were found to be independent prognostic factors associated with survival in patients with COS (all P 39 years, the presence of distant metastasis, no history of having undergone any surgery, and tumor size >103 mm were found to be associated with poor prognosis in patients, while the primary site of the mandible and no history of having undergone radiotherapy showed associations with a more favorable prognosis in patients. Next, nomograms were constructed to predict the OS and CSS in patients with COS. We constructed nomograms that can provide accurate survival predictions in patients with chondroblastic osteosarcoma. These nomograms can help surgeons customize the treatment strategies for patients with chondroblastic osteosarcoma.

Objective To introduce a method of accurately measuring the equivalent dose received by radiation-sensitive organs using the thermoluminescent dosimeter (TLD) and to provide reference values for future studies associated with radiation protection in patients undergoing lumbar spine surgeries. Methods After careful selection and preparation, TLD chips were used to obtain measurements from the eyes, thyroid glands, breasts, and gonads of 20 patients undergoing lumbar spine surgeries. The results were obtained via air kerma conversion-related calculations. Results The overall radiation exposures absorbed perioperatively by the eyes, thyroid glands, right breasts, left breasts, right ovaries, left ovaries, and testes were 0.41 ± 0.13, 1.43 ± 0.45, 6.95 ± 3.63, 9.50 ± 6.14, 29.86 ± 28.62, 23.47 ± 22.10, and 5.41 ± 1.86 mSv, respectively. A single computed tomography (CT) scan contributed to more than 75% of the overall dose received regardless of the position used. Conclusions Patients received significantly higher radiation doses from CT scans than from regular digital radiograph examinations. These radiation doses were concentrated in the regional area of scanning. Our results indicate the necessity and benefits of radiation protection measures, especially for the organs researched herein, when patients undergoing lumbar surgeries require radiographic diagnostic examinations.

BACKGROUND Controversy still exists regarding the optimal fusion technique for the treatment of unstable lumbar spondylolisthesis. OBJECTIVE To evaluate the safety and efficacy of modified facet joint fusion (MFF). METHODS A total of 491 patients with unstable lumbar spondylolisthesis who underwent MFF were retrospectively reviewed. Computed tomography was used to evaluate the fusion rate of MFF at 6- and 12-mo follow-up postoperatively. Clinical outcomes included visual analog scale pain scores for low back pain (VAS-LBP) and leg pain (VAS-LP), Japanese Orthopedic Association scores (JOA), and Oswestry Disability Index (ODI), all of which were obtained preoperatively and postoperatively at 1-, 3-, 6-, and 12-mo follow-up times. The clinical outcomes were determined to be excellent, good, fair, or poor according to the MacNab classification at the last follow-up time. RESULTS Of the 491 patients, the fusion rates at the 6-mo and 1-yr follow-up were 56.8% and 96.1%, respectively. Between baseline and 1-yr follow-up time, VAS-LP and VAS-LBP improved from 5.6 ± 0.9 to 0.4 ± 0.5 and 5.1 ± 1.2 to 1.5 ± 0.9, respectively (P

A retrospective case-control study.To compare postoperative blood loss, amount of allogeneic blood transfusion, removal time of drainage tube, length of hospital stay, and complications associated with tranexamic acid (TXA).Spinal fusion surgery can be associated with significant blood loss. To the best of our knowledge, very few published studies exist reporting the effect of topical use of tranexamic acid (tTXA) on decreasing the blood loss in patients undergoing posterior lumbar spinal fusions.We conducted a retrospective nonrandomized case-control study of 100 adults undergoing posterior lumbar spinal fusion surgery. In the tTXA group (n = 50), wound surface was soaked with TXA (1 g in 100 mL saline solution) for 5 minutes before wound closure. In the control group (n = 50), wound surface was soaked with the same volume of normal saline. The postoperative blood loss, removal time of drainage tube, amount of allogeneic blood transfusion, and length of hospital stay were compared between the two groups. And the complications of TXA were also collected.In the tTXA group, the postoperative blood loss, removal time of drainage tube, postoperative length of hospital stay were significantly lower than those in the control group (155.2 ± 104.3 mL vs. 278.6 ± 124.1 mL, 2.0 ± 0.6 d vs. 2.4 ± 0.5 d, 4.7 ± 1.4 d vs. 5.6 ± 2.3 d, P 0.05, respectively). There was no significant difference in blood transfusion between two groups. No significant changes were noticed in terms of coagulation function, and no complications associated with TXA were observed.tTXA can significantly reduce postoperative blood loss, accelerate removal of drainage tube, shorten the duration of hospital stay, while not increasing the complication incidence in patients undergoing posterior lumbar spinal fusion surgery.3.

Hidden blood loss (HBL) plays an important role in lumbar fusion surgery. However, there was huge computation error when calculating hidden loss in previous studies because they regarded the volume of drainage as postoperative blood loss. We should not ignore the fact that the composition of drainage varies from person to person and also with time-lapse after operation. The purpose of this study was to demonstrate a more accurate HBL calculation formula by comparing it with previous formula and to address the importance of HBL in patients undergoing posterior lumbar fusion surgeries.For each patient, the HBL was calculated by previous formula and our recommendable formula. We compared the result of HBL calculated by two different methods. At the same time, we explored the HBL in patients undergoing posterior lumbar fusion surgeries with various levels.In our study, the average total blood loss was 771ml. The mean intraoperative blood loss was 268ml, and the total volume of post-operative drainage is 276ml. The mean hidden loss of 90 patients calculated with previous method was 227ml and 29.4% of total loss. When taking change of drainage HCT into account, the mean hidden loss calculated with our recommendable method was 362.8ml and 47% of total loss. The results were significantly different (P0.01). There was no significant difference in the percentage of the HBL between patients with single or multiple surgical levels.There is often a substantial unmeasured blood loss in lumbar fusion surgeries. However, the component of drainage changed radically with time, we should take the true blood contained in drainage into considerations when calculating the HBL.Our research is a case-control study and the level of proof is III.

Backgroud Few studies compared radiographic and clinical outcomes between oblique lumbar interbody fusion and posterior lumbar interbody fusion in degenerative lumbar scoliosis. Methods This study retrospectively analyzed the case data of 40 patients with degenerative lumbar scoliosis in our hospital from July 2016 to October 2018. Among which,19 cases underwent oblique lumbar Interbody fusion(OLIF group) and 21 cases underwent posterior lumbar interbody fusion(PLIF group). The duration of the operation, volume of intraoperative hemorrhage, incision length, bed rest time, length of hospital stay, and complications were recorded for all patients. The clinical effects of 40 patients were evaluated by VAS for back pain and Oswestry Disability Index (ODI) and The radiographic parameters were evaluated using the lumbar scoliosis Cobb angle, sagittal vertical axis(SVA), coronal vertical axis(CVA), lumbar lordosis(LL), pelvic tilt(PT), sacral slope(SS), and Disc height(DH). Results The duration of the operation, the volume of intraoperative hemorrhage, incision length, bed rest time, length of hospital stay of the OLIF group were shorter than the PLIF group( P ＜ 0.05 ). The VAS scores for back pain, the ODI of the two groups were significantly decreased, which compared with the preoperative( P ＜ 0.05 )，which in OLIF group was significantly more decreased than in PLIF( P ＜ 0.05 ) at 7 days and 3 months postoperatively, but at the last follow-up there were no significant difference between the two groups( P ＞ 0.05 ); The lumbar scoliosis Cobb angle, SVA, CVA, PT, LL, SS were significantly improved postoperatively( P ＜ 0.05 ). The OLIF group showed higher DH, smaller Cobb angle, and greater LL than the PLIF group at any time point( P ＜ 0.05 ). but there were no significant difference in SVA, CVA, PT and SS between the two groups at any follow-up points( P ＞ 0.05 ). The overall complication rate was slightly higher in the PLIF group（47.62%）than in the OLIF group（26.32%）without significant difference(x 2 =1.931, P =0.165). But the incidence of major complications in the PLIF group was significantly higher than that in the OLIF group (Fisher, P =0.026). Conclusion OLIF provides an alternative minimally invasive treatment for DLS, which compared with PLIF. It has the characteristics of a small incision, rapid recovery, fewer complications related to the surgical approach, and satisfactory orthopedics. Keywords : Minimally invasive, Oblique lumbar interbody fusion, Degenerative adult lumbar scoliosis , Posterior lumbar interbody fusion

Background Osteosarcoma is one of the most common primary bone tumour in children and young patients, and the third most common among adults. Its main treatment option is currently based on neoadjuvant or adjuvant chemoradiotherapy along with the lesion's surgical resection. The current study's primary aim is to examine the clinical therapeutic impacts of combined methotrexate, along with other chemotherapeutic agents to treat children and young adults suffering from osteosarcoma. Methods We will perform a comprehensive literature search in English database (PubMed, EMBASE, Cochran Library CINAHL, and PsycINFO) and Chinese database (Chinese National Knowledge Infrastructure, VIP information database, Chinese Biomedical Database, and WanFang Database) with no language restriction from their inception to the search date. Additionally, two independent authors will screen the works of literature obtained from these databases, obtain information, and examine the risks of data included for the studies' bias. Furthermore, we intend to employ the Q statistics as well as I2 statistics to calculate heterogeneity among each study's analysis. Accordingly, we will utilize the funnel plots and Egger test to assess the possibility of publication bias where relevant. Results The current study aims to provide significant information regarding the clinical therapeutic impacts of combines methotrexate along with other chemotherapeutic agents to treat children and young adults suffering from osteosarcoma. Conclusions The present study will generate compelling evidence of combined methotrexate as well as other chemotherapeutic agents for osteosarcoma among children and young adults. Also, it will provide clinical practice suggestions. Ethics and dissemination The study is founded upon published data. Therefore, there is no requirement for ethics approval. Osf registration number March 26, 2021.osf.io/a23rc. (https://osf.io/a23rc/).

SPIRIT 2013 checklist: recommended items to address in a clinical trial protocol and related documents. (DOC 124 kb)

Background Tranexamic acid (TXA) has been routinely delivered in multisegmental spinal decompression and bone graft fusion surgeries with satisfactory outcomes in minimizing gross blood loss and transfusion demands. However, concerns remain that intravenously delivered TXA (ivTXA) may increase risks of postoperative convulsive seizures and systemic thrombogenicity. Topical use of TXA (tTXA), being more targeted to the surgical bleeding site while minimizing patient systemic exposure to ivTXA, has been successfully applied to attenuate blood losses and transfusion requirements in hip and knee arthroplasty. Yet, randomized controlled trials on tTXA efficacy and safety are still lacking in spinal surgeries. With this knowledge gap, we hypothesize that tTXA exhibits non-inferiority to ivTXA in blood conservation and clinical safety in multisegmental spinal decompression and bone graft fusion surgeries. Methods A prospective, randomized, double-blind, non-inferiority study design will be adopted. The target sample size is 176. Eligible patients will be randomly allocated to receive either ivTXA or tTXA treatment. The primary end point is the perioperative total blood loss. Secondary end points consist of visible blood losses (intraoperative, postoperative 0–24 h, postoperative 0–48 h, combined perioperative blood loss, total postoperative blood loss), postoperative hidden blood loss, plasma TXA levels, postoperative conventional coagulation monitoring (prothrombin time, activated partial thromboplastin time, fiber Bragg grating, international normalized ratio), postoperative thromboelastography monitoring (reaction time, clot formation time, clot strength, fibrinolysis), postoperative hemoglobin nadir (within postoperative 48 h), perioperative transfusion amounts and rates, and length of hospital stay. Safety end points will be monitored too. Discussion This proposed study will contribute to expanding clinical evidences of tTXA for bleeding management in major spinal surgeries. This will be a high-quality prospective randomized trial with sufficient sample size, strict methodology, and few design deficits. It will investigate the potentiality of tTXA as an alternative to ivTXA in improving the current standard of care in multisegmental spinal surgeries, thereby optimizing the enhanced recovery after surgery scheme in spinal surgeries. Trial registration ClinicalTrials.gov, NCT03011866. Registered on 5 January 2017. Electronic supplementary material The online version of this article (10.1186/s13063-019-3231-9) contains supplementary material, which is available to authorized users.

Objective To identify risk factors for postoperative complications associated with growing rod surgery for early-onset scoliosis (EOS). Methods A total of 55 consecutive patients underwent growing rod surgery for EOS were examined from database. Data included age at initial surgeries, sex, diagnosis, body mass index (BMI), duration of follow-up, initial and final measure of major curve, T2–5, T5–12, T10–L2, and T12–S1 kyphosis angles, levels and type of instrumentation, total number of surgeries, number of rods inserted, number of lengthenings, lengthening intervals and rod location were studied. Risk factors for postoperative complications were analyzed using binomial multiple logistic regression analysis. Results Postoperative complications were associated with 37 of 272 procedures (14%) and affected 23 patients (42%). Complications included 25 implant-related failures (66%), 4 alignment complications (11%), 4 infections (11%), 1 neurological impairment (3%), 3 respiratory problems, 2 gastrointestinal problems, 1 urinary problem, and 1 dural tear. The most frequent implant-related failure was dislodged implant (76%) and 92% of the dislodgements occurred at the proximal foundation. Binomial multiple logistic regression analysis demonstrated that curve magnitude in last follow-up (OR: 1.042; P =0.036), duration between growing-rod lengthening procedures (OR: 1.121; P =0.003) and duration of follow-up (OR: 1.079; P =0.001) maintained its significance in predicting likelihood of postoperative complications. Conclusion The occurrence of postoperative complications in growing rod surgery for EOS is most likely multifactorial and is related to curve magnitude in last follow-up and duration between growing-rod lengthening procedures.

It is widely accepted that tranexamic acid (TXA) effectively reduces blood losses and transfusions in major surgeries. However, limited studies investigated the role of TXA in conserving blood and saving operative time in spine surgeries.This meta-analysis was conducted to gather scientific evidence for TXA efficacy on conserving blood and saving operative time in spine surgeries.A meta-analysis was performed.Eighteen RCTs and 18 non-RCT studies involving 2,572 patients were included in the final analyses, comparing the effectiveness of intravenous TXA with a placebo/no treatment group.Outcomes of interest included intraoperative, postoperative, and perioperative blood losses, allogeneic blood transfusion rates, cell salvage transfusion amounts, operative time, and the number of postoperative thrombosis events.An exhaustive literature search was conducted in the MEDLINE and EMBASE databases from January 2000 through March 2017. Meta-analysis was performed using Review Manager (RevMan) version 5.0. For continuous outcomes, the means and standard deviations were pooled to a mean difference and 95% confidence interval (CI). Odds ratios (OR) and 95% CI were calculated for dichotomous outcomes. The quantity of heterogeneity was assessed using ISignificantly reduced intraoperative (weighted mean difference [WMD]=-280.09.00, p.00001), postoperative (WMD=-120.15, p.00001), perioperative (WMD=-310.86, p.00001) blood losses, cell salvage transfusion amount (WMD=-471.79, p=.01), perioperative transfusion rate (odds ratio [OR], 0.33 [0.17, 0.65], p=.001), and operative time (WMD=-4.69, p=.003) were observed in TXA group. Furthermore, subgroup analysis revealed that high-dose TXA could reduce both intraoperative-perioperative allogeneic transfusion rates and operative time, whereas low dose of the drug does not convey such effects.With the most comprehensive literature inclusion up to the present, this meta-analysis suggests that intravenous TXA use constitutes an important measure for conserving blood and saving operative time in spinal surgeries. High-dose TXA significantly reduces intraoperative-perioperative allogeneic transfusion rates and operative time, whereas low-dose TXA does not convey such efficacies. Larger prospective trials are still required to define the optimal regimen and to confirm the safety of TXA use in such surgeries.

Optimal surgical technique to treat lumbar disc herniation (LDH) remains controversial. We described a small incision discectomy technique (SID), and to evaluate its safety and efficacy. A retrospective study involving 98 consecutive patients with LDH managed by SID was conducted. All patients were followed up for 5 years. Outcomes included visual analogue scale (VAS), Japanese Orthopedic Association (JOA), operative time, length of incision, blood loss, hospital stay, hospitalization costs, x-ray exposure, reoperation, and complications. The results were determined to be excellent, good, fair, or poor according to the MacNab classification. All patients completed the 5-year follow-up. Relative to preoperative scores, VAS and JOA were both significantly improved. As a whole, 93.8% (92/98) patients showed excellent or good results, 3.1% (3/98) fair, and 3.1% (92/98) poor. The operation time, length of incision, blood loss, and hospital stay were 50 ± 11.1 minutes, 2.2 ± 0.3 cm, 35 ± 3.5 mL, and 4.3 ± 0.2 days, respectively. Additionally, compared with previous literature reports, the hospitalization costs and x-ray exposure were apparently less. The reoperation and recurrence rate were 3.2% and 2.1%. No complications were observed. From these data we conclude that SID appears to be a safe, cost-effective technique for LDH, and has lower x-rays exposure time when compared with literature of percutaneous endoscopic lumbar discectomy (PELD).

Background: Despite introducing novel analgesics, pain management for spine surgery remains a challenge. Multimodal pain control has recently gained popularity in surgical spine care. We proposed a novel management approach using multimodal cocktail analgesics. Injection to skin surrounding surgical incision site will be given perioperatively. This study evaluates the safety and efficacy of cocktail analgesic injection on pain management following lumbar spinal fusion surgery. Methods: Thirty-six patients with degenerative lumbar spinal diseases on the waiting list for lumbar spinal fusion surgery will be recruited. Patients will be randomly assigned to receive either cocktail analgesic injection or sterile saline before surgical wound closure. All patients will routinely receive postoperative intravenous patient-controlled analgesia (IV-PCA) with sufentanil on an as-needed basis without a basal dose. The primary outcome is perceived pain intensity as measured by visual analog pain score. Secondary outcomes include sufentanil consumption, time to first use of IV-PCA, rescue analgesics consumption, and the presence of adverse effects. Findings of this interventional trial will provide novel evidence supporting the superior effect of cocktail analgesic injection during surgery. Trial registration number: ChiCTR-IPR-17013094.

Intravenous leiomyomatosis (IVL) is a rare benign tumor. The study aimed to assess outcomes of patients treated surgically for IVL. Between November 2002 and January 2015, 76 patients were treated for IVL. The stage of IVL was evaluated preoperatively by echocardiography and enhanced computerized tomography (CT) scan, and graded into 4 stages according to intravascular tumor progression. We recorded age, lower limb edema before surgery, surgical parameters, and hospitalization expenses. Patients were followed up every 6 months and tumor recurrence was assessed by CT and ultrasound. Patients were followed up for a mean of 4.5 ± 2.5 years (range 1–13 years) and there was no operative, hospital, or long-term mortality or were lost to follow-up. The rate of lower extremity edema, amount of blood loss, postoperative transfusion, length of intensive care unit (ICU) stay, postoperative hospitalization, and hospitalization expenses differed significantly between patients at different presurgery stages. Tumors recurred in 4 of 7 patients with stage I IVL that opted for surgery that preserved the ovaries and uterus. No recurrence was observed in patients graded stage II or more, in all of which the uterus and ovaries were removed. Recurrence was observed in only 4 of 76 cases of IVL, all of whom opted for surgery that spared the ovaries and uterus. Different surgical strategies should be decided based on the staging to completely remove the tumor and ensure the safety of patients. Removal of both ovaries is necessary for inhibiting tumor growth and avoiding recurrence.

Spinal fusion surgery is associated with significant blood loss, which may result in potential clinical complications, it is necessary to take safe and effective measures to reduce blood loss in surgery. We perform this study to assess the impact of three different hemostatic materials on perioperative blood loss. We performed a Randomized Controlled Trial research and recruited patients with lumbar disease into the study between November 2013 and March 2015. All the participants were randomly assigned to 3 groups using a simple equal probability randomization scheme: Group A (Stypro hemostatic sponge), Group B (Collagen hemostatic sponge) and Group C (gelatin sponge). We compared postoperative blood loss between these 3 groups. In our study, drainage volume in the first 24 h of patients in Group A and B is significantly smaller, as well as total postoperative volumes of drainage (p

DUT2014 is a computational program developed by our team for the elastic-plastic time history analysis of super high-rise building structures. The integrated platform code is open source, which has all the materials and elements for the structural analysis of super high-rise buildings. Moreover, the integrated platform has a new element state transition algorithm (STP), which greatly improves the computational efficiency of elastic-plastic time history analysis. Midas is a finite element analysis software, which has good elastic analysis function and non-linear analysis function, and it has good pre-processing function. Preprocessing of DUT2014 is a command stream format in text format, and its modeling function is relatively cumbersome. In order to realize the customization of DUT2014 modeling function, this paper decided to develop an interface program to transform Midas model data file to DUT2014 model data file. This paper establishes an interface program for converting Midas structured data model file into DUT2014 structured data model file by using Microsoft Visual C++ programming program. In order to verify the correctness of structural data model transformation, this paper will use interface program to transform three different scale structures, and then verify the accuracy of the interface by comparing the quality information, modal calculation results, elastic time history response and elastic-plastic time history response of the model before and after transformation.

In spinal fusion surgery, total blood loss (TBL) is composed of visible blood loss from the surgical field and wound drainage, and hidden blood loss (HBL). Until now, no published studies exist reporting the effect of topical use of tranexamic acid (tTXA) on HBL in patients undergoing poster

Purpose Hidden blood loss (HBL) plays an important role in lumbar fusion surgery. However, there was huge computation error when calculating hidden loss in previous studies because they regarded the volume of drainage as postoperative blood loss. We should not ignore the fact that the composition of drainage varies from person to person and also with time-lapse after operation. The purpose of this study was to demonstrate a more accurate HBL calculation formula by comparing it with previous formula and to address the importance of HBL in patients undergoing posterior lumbar fusion surgeries. Methods For each patient, the HBL was calculated by previous formula and our recommendable formula. We compared the result of HBL calculated by two different methods. At the same time, we explored the HBL in patients undergoing posterior lumbar fusion surgeries with various levels. Results In our study, the average total blood loss was 771 mL. The mean intraoperative blood loss was 268 mL, and the total volume of postoperative drainage is 276 mL. The mean hidden loss of 90 patients calculated with previous method was 227 mL and 29.4 % of total loss. When taking change of drainage HCT into account, the mean hidden loss calculated with our recommendable method was 362.8 mL and 47 % of total loss. The results were significantly different ( P Conclusions There is often a substantial unmeasured blood loss in lumbar fusion surgeries. However, the component of drainage changed radically with time, we should take the true blood contained in drainage into considerations when calculating the HBL.