Spatial Distribution of Brønsted Acid Sites Determines the Mobility of Reactive Cu Ions in the Cu-SSZ-13 Catalyst during the Selective Catalytic Reduction of NOx with NH3.

The formation of dimer-Cu species, which serve as the active sites of the low-temperature selective catalytic reduction of NOx with NH3 (NH3-SCR), relies on the mobility of CuI species in the channels of the Cu-SSZ-13 catalysts. Herein, the key role of framework Brønsted acid sites in the mobility of reactive Cu ions was elucidated via a combination of density functional theory calculations, in situ impedance spectroscopy, and in situ diffuse reflectance ultraviolet-visible spectroscopy. When the number of framework Al sites decreases, the Brønsted acid sites decrease, leading to a systematic increase in the diffusion barrier for [Cu(NH3)2]+ and less formation of highly reactive dimer-Cu species, which inhibits the low-temperature NH3-SCR reactivity and vice versa. When the spatial distribution of Al sites is uneven, the [Cu(NH3)2]+ complexes tend to migrate from an Al-poor cage to an Al-rich cage (e.g., cage with paired Al sites), which effectively accelerates the formation of dimer-Cu species and hence promotes the SCR reaction. These findings unveil the mechanism by which framework Brønsted acid sites influence the intercage diffusion and reactivity of [Cu(NH3)2]+ complexes in Cu-SSZ-13 catalysts and provide new insights for the development of zeolite-based catalysts with excellent SCR activity by regulating the microscopic spatial distribution of framework Brønsted acid sites.

Unexpected Promotion Effect of H2O on the Selective Catalytic Reduction of NOx with NH3 over Cu-SSZ-39 Catalysts.

Water molecules commonly inhibit the selective catalytic reduction (SCR) of NOx with NH3 on most catalysts, and water resistance is a long-standing challenge for SCR technology. Herein, by combining experimental measurements and density functional theory (DFT) calculations, we found that water molecules do not inhibit and even promote the NOx conversion to some extent over the Cu-SSZ-39 zeolites, a promising SCR catalyst. Water acting as a ligand on active Cu sites and as a reactant in the SCR reaction significantly improves the O2 activation performance and reduces the overall energy barrier of the catalytic cycle. This work unveils the mechanism of the unexpected promotion effect of water on the NH3-SCR reaction over Cu-SSZ-39 and provides fundamental insight into the development of zeolite-based SCR catalysts with excellent activity and water resistance.

Hydrothermal Aging Alleviates the Phosphorus Poisoning of Cu-SSZ-39 Catalysts for NH3-SCR Reaction.

As a new type of catalyst with the potential for commercial application in NOx removal from diesel engine exhausts, Cu-SSZ-39 catalysts must have excellent resistance to complex and harsh conditions. In this paper, the effects of phosphorus on Cu-SSZ-39 catalysts before and after hydrothermal aging treatment were investigated. Compared with fresh Cu-SSZ-39 catalysts, phosphorus poisoning significantly decreased the low-temperature NH3-SCR catalytic activity. However, such activity loss was alleviated by further hydrothermal aging treatment. To reveal the reason for this interesting result, a variety of characterization techniques including NMR, H2-TPR, X-ray photoelectron spectroscopy, NH3-TPD, and in situ DRIFTS measurements were employed. It was found that Cu-P species produced by phosphorus poisoning decreased the redox ability of active copper species, resulting in the observed low-temperature deactivation. After hydrothermal aging treatment, however, Cu-P species partly decomposed with the formation of active CuOx species and a release of active copper species. As a result, the low-temperature NH3-SCR catalytic activity of Cu-SSZ-39 catalysts was recovered.

Insights into SO2 Poisoning Mechanisms of Fresh and Hydrothermally Aged Cu-KFI Catalysts for NH3-SCR Reaction.

The complex poisoning of Cu-KFI catalysts by SO2 and hydrothermal aging (HTA) was investigated. The low-temperature activity of Cu-KFI catalysts was restrained by the formation of H2SO4 and then CuSO4 after sulfur poisoning. Hydrothermally aged Cu-KFI exhibited better SO2 resistance than fresh Cu-KFI since HTA significantly reduced the number of Brønsted acid sites, which were considered to be the H2SO4 storage sites. The high-temperature activity of SO2-poisoned Cu-KFI was basically unchanged compared to the fresh catalyst. However, SO2 poisoning promoted the high-temperature activity of hydrothermally aged Cu-KFI since it triggered CuOx into CuSO4 species, which was considered as an important role in the NH3-SCR reaction at high temperatures. In addition, hydrothermally aged Cu-KFI catalysts were more easily regenerated after SO2 poisoning than fresh Cu-KFI on account of the instability of CuSO4.

Risk factors for residual back pain following percutaneous vertebral augmentation: the importance of paraspinal muscle fatty degeneration.

PURPOSE: Residual back pain (RBP) after percutaneous vertebral augmentation (PVA) still exists considerable, and it even affects daily life due to moderate or severe back pain. A variety of risk factors have been previously identified for developing residual back pain. However, there are conflicting reports regarding the association between sarcopenia and residual back pain. As such, the aim of this study was to investigate whether paraspinal muscle fatty degeneration is a predictor of residual back pain. METHODS: We retrospectively reviewed the medical records of patients with single-segment OVCF who underwent PVA from January 2016 to January 2022. Patients were divided into RBP group (86 patients) and control group (790 patients) according to whether the visual analog scale (VAS) score ≥ 4. The clinical and radiological data were analyzed. Paraspinal musculature fatty degeneration was measured using the Goutallier classification system (GCS) at the L4 - 5 intervertebral disc level. Univariate and multivariate logistic regression analyses were performed to identify risk factors. RESULTS: The results of multivariate logistical regression analysis revealed that posterior fascia injury (odds ratio (OR) = 5.23; 95% confidence interval (CI) 3.12-5.50; P < 0.001), as regards paraspinal muscle fatty degeneration, including Goutallier grading (OR = 12.23; 95% CI 7.81-23.41; P < 0.001), fCSA (OR = 3.06; 95% CI 1.63-6.84; P = 0.002), fCSA/CSA (%) (OR = 14.38; 95% CI 8.80-26.29; P < 0.001), and facet joint violation (OR = 8.54; 95% CI 6.35-15.71; P < 0.001) were identified as independent risk factors for RBP. CONCLUSIONS: Posterior fascia injury, paraspinal muscle fatty degeneration, and facet joint violation were identified as independent risk factors for RBP, with paraspinal muscle fatty degeneration playing an important role.

CircNFIB inhibits tumor growth and metastasis through suppressing MEK1/ERK signaling in intrahepatic cholangiocarcinoma.

BACKGROUND: Considerable evidence shows that circular RNAs (circRNAs) play an important role in tumor development. However, their function in intrahepatic cholangiocarcinoma (ICC) metastasis and the underlying mechanisms are incompletely understood. METHODS: circNFIB (hsa_circ_0086376, termed as cNFIB hereafter) was identified in human ICC tissues through circRNAs sequencing. The biological role of cNFIB was determined in vitro and in vivo by gain or loss of functional experiments. Fluorescence in situ hybridization (FISH), RNA immunoprecipitation (RIP) and RNA pull-down assays were conducted to analyze the interaction of cNFIB with dual specificity mitogen-activated protein kinase kinase1 (MEK1). Duolink in situ proximity ligation assay (PLA) and coimmunoprecipitation (co-IP) assay were used to investigate the effects of cNFIB on the interaction between MEK1 and mitogen-activated protein kinase 2 (ERK2). Finally, a series of in vitro and in vivo experiments were performed to explore the influences of cNFIB on the anti-tumor activity of trametinib (a MEK inhibitor). RESULTS: cNFIB was significantly down-regulated in human ICC tissues with postoperative metastases. The loss of cNFIB was highly associated with aggressive characteristics and predicted unfavorable prognosis in ICC patients. Functional studies revealed that cNFIB inhibited the proliferation and metastasis of ICC cells in vitro and in vivo. Mechanistically, cNFIB competitively interacted with MEK1, which induced the dissociation between MEK1 and ERK2, thereby resulting in the suppression of ERK signaling and tumor metastasis. Moreover, we found that ICC cells with high levels of cNFIB held the potential to delay the trametinib resistance. Consistently, in vivo and in vitro studies demonstrated that cotreatment with trametinib and lentivirus vector encoding cNFIB showed greater inhibitory effect than isolated trametinib treatment. CONCLUSIONS: Our findings identified that cNFIB played a key role in ICC growth and metastasis by regulating MEK1/ERK signaling. Given the efficacy of cNFIB modulation on ICC suppression and trametinib sensitivity, cNFIB appears to be a potential therapeutic molecule for ICC treatment.

The role and mechanism of noncoding RNAs in regulation of metabolic reprogramming in hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) is the most common type of primary liver cancer. Metabolic reprogramming is considered to be an important hallmark of cancer. Emerging studies have demonstrated that noncoding RNAs (ncRNAs) are closely associated with metabolic reprogramming of HCC. NcRNAs can directly regulate the expressions or functions of metabolic enzymes or indirectly regulate the metabolism of HCC cells through some vital signaling pathways. Until now, the mechanisms of HCC development and progression remain largely unclear, and understanding the regulatory mechanism of ncRNAs on metabolic reprogramming of HCC may provide an important basis for breakthrough progress in the treatment of HCC. In this review, we summarize the ncRNAs involved in regulating metabolic reprogramming of HCC. Specifically, the regulatory roles of ncRNAs in glucose, lipid and amino acid metabolism are elaborated. In addition, we discuss the molecular mechanism of ncRNAs in regulation of metabolic reprogramming and possible therapeutic strategies that target the metabolism of cancer cells by modulating the expressions of specific ncRNAs.

Si/Al Ratio Determines the SCR Performance of Cu-SSZ-13 Catalysts in the Presence of NO2.

A comparative study was performed to investigate the NH3-selective catalytic reduction (SCR) reaction activity of Cu-SSZ-13 zeolites having Si/Al ratios (SARs) of 5, 18, and 30. Remarkably, the Cu-SSZ-13 zeolite catalysts exhibited completely opposite behaviors as a function of SAR under standard SCR (SSCR) and fast SCR (FSCR) reaction atmospheres. Under SSCR conditions, the NOx conversion increased as expected with the decreasing SAR. Under FSCR conditions, however, the NOx conversion decreased as the SAR decreased, contrary to expectations. In this study, based on characterization of the catalysts by X-ray diffraction, transmission electron microscopy, electron paramagnetic resonance, H2-temperature-programmed reduction, temperature-programmed desorption, and diffuse reflectance infrared Fourier transform spectroscopy, together with theoretical calculations, the authors found that the amount of Brønsted acid sites goes up while the SAR goes down, leading to an increase in the accumulation of NH4NO3 under FSCR reaction conditions. Moreover, the accumulated NH4NO3 is of greater stability for those low SAR Cu-SSZ-13 catalysts. These two reasons cause the FSCR performance of Cu-SSZ-13 to decrease with a decrease in SAR. As a result, the NO2 effect on SCR activity changes from promotion to inhibition as the SAR decreases.

Reaction Pathways of Standard and Fast Selective Catalytic Reduction over Cu-SSZ-39.

Cu-SSZ-39 exhibits excellent hydrothermal stability and is expected to be used for NOx purification in diesel vehicles. In this work, the selective catalytic reduction (SCR) activities in the presence or absence of NO2 were tested over Cu-SSZ-39 catalysts with different Cu contents. The results showed that the NOx conversion of Cu-SSZ-39 was improved by NO2 when NO2/NOx = 0.5, especially for the catalysts with low Cu loadings. The kinetic studies showed two kinetic regimes for fast SCR from 150 to 220 °C due to a change in the rate-controlling mechanism. The activity test and diffuse reflectance infrared Fourier transform spectra demonstrated that the reduction of NO mainly occurred on the Cu species in the absence of feed NO2, and when NO2/NO = 1, NO could react with NH4NO3 on the Brønsted acid sites in addition to undergoing reduction on Cu species. Thus, NO2 can promote the SCR reaction over Cu-SSZ-39 by facilitating the formation of surface nitrate species.

Reaction Pathways of the Selective Catalytic Reduction of NO with NH3 on the α-Fe2O3(012) Surface: a Combined Experimental and DFT Study.

Fe2O3-based catalysts have promising potential in the selective catalytic reduction (SCR) of NO with NH3 with the advantages of environmental friendliness, excellent medium-high SCR activity, good N2 selectivity, and high SO2 tolerance. However, the NH3-SCR mechanism over Fe2O3-based catalysts remains highly uncertain and controversial due to the complex nature of the SCR reaction. Herein, the NH3-SCR reaction pathways over the α-Fe2O3(012) surface are elucidated at the atomic level by density functional theory calculations and experimental measurements. We demonstrate that, different from the NH3 activation mechanism in numerous SCR catalytic systems, the reaction tends to follow the NO activation mechanism, in which NO activated at Fe sites reacts with NH3 to form a NH2NO intermediate and further decomposes into N2 and H2O, in synchronization with the formation of a surface OH group. Subsequently, the catalyst is regenerated by an O2-assisted surface-dehydrogenation process. The activation of NO as well as the formation of the NH2NO intermediate is the rate-determining step of the complete SCR cycle. This study enhances the atomic-level understanding toward the NH3-SCR reaction and provides insights for the development of Fe2O3-based SCR catalysts.

Radiological and clinical differences between robotic-assisted pedicle screw fixation with and without real-time optical tracking.

OBJECTIVE: To study radiological and clinical differences between robotic-assisted pedicle screw fixation with and without real-time optical tracking. METHODS: Patients who underwent lumbar internal fixation in our hospital from June 2017 to February 2020 were divided into Tinavi group (with optical tracking) and Renaissance group (without optical tracking) according to assisted technology. The imaging data of the patients were collected, and the accuracy of screw implantation was measured according to Rampersaud A-D grade. Clinical outcomes such as operative time, fluoroscopic time and radiations dose were also collected. RESULTS: A total of 376 patients were included, including 201 patients in the Tinavi group with 968 screws implanted and 175 patients in the Renaissance group with 822 screws implanted. The accuracy of "perfect" and "clinically acceptable" pedicle screw implantation in the Tinavi group was 94.9%-98.7%, respectively, while in the Renaissance group was 91.2%-94.5%, respectively. There was significant difference between the two groups (P < 0.05). The operative time and operative time per screw in the Tinavi group were lower than those in the Renaissance group. However, fluoroscopic time per screw and radiations dose of the Tinavi group were significantly higher than those of the Renaissance group. CONCLUSION: Optical tracking in robotic system appears to increase accuracy because of the ability to detect the real-time position of the patient. Although there are still many problems to be solved, robot with optical tracking system shows its great potential in clinical application.

Trends of epidemiological characteristics of traumatic spinal cord injury in China, 2009-2018.

OBJECTIVE: We focus on providing the first comprehensive national dataset on the incidence, injury aetiology and mortality of TSCI in China. METHODS: A multi-stage stratified cluster sampling method was used. We included TSCI cases from all hospitals in three regions, nine provinces and 27 cities in China via search of electronic medical records and retrospectively analysed the characteristics of TSCI in China from 2009 to 2018. We estimated the incidence of TSCI in the total population and subgroups. RESULTS: There were 5954 actual cases in 2009, corresponding to a total estimated TSCI incidence of 45.1 cases per million population (95% CI, 44.0-46.3). There were 10,074 actual cases in 2018, corresponding to a total estimated TSCI incidence of 66.5 cases per million population (95% CI, 65.2-67.8) (P < 0.001; annual average percentage change (AAPC), 4.4%). From 2009 to 2018, the incidence of almost all sex/age groups showed an increasing trend over time (P < 0.001; AAPC, 0.7-8.8%). The elderly population (aged 65-74) displayed the highest incidence of TSCI (with an average annual incidence of 127.1 cases per million [95% CI, 119.8-134.3]). CONCLUSIONS: The TSCI incidence increased significantly from 2009 to 2018. The incidence in the elderly populations was consistently high and continues to increase over time. The mortality of TSCI patients in hospitals is relatively low and continues to decrease each year, but elderly individuals remain at a high risk of hospital death.

Epidemiological characteristics of traumatic spinal cord injury in Xi'an, China.

STUDY DESIGN: A hospital-based retrospective epidemiological study. OBJECTIVE: To describe the demographic and epidemiological characteristics of patients with traumatic spinal cord injury (TSCI) in Xi'an to help health-related institutions formulate corresponding measures. SETTING: People with TSCI, all spine centres and orthopaedic centres in Xi'an, China. METHODS: We retrospectively reviewed the medical records of the all spine centers or orthopedic centers in Xi'an according to the International Classification of Disease Version 10 (ICD-10) and diagnostic code of TSCI. Variables included gender, age, medical insurance, etiology, occupation, level of injury, and severity of injury, multiple injury, complication, treatment, and so on. RESULTS: The study included the medical records of 1730 patients with TSCI from 2014 to 2018. The estimated annual incidence rate increased from 39.0 cases (95% CI, 34.7-43.3 cases) per 1 million persons in 2014 to 43.2 cases (95% CI, 39.0-47.5 cases) per 1 million persons in 2018. The leading cause of TSCI was high falls (35.5%, 614 cases). The most common injury site was the cervical spinal cord, accounting for 55.7% (963 cases). The degree of injury severity with the highest proportion was incomplete tetraplegia (47.2%, 816 cases). In addition, 71.4% (1236 cases) of TSCI cases had spinal fracture or dislocation. CONCLUSIONS: There are specific epidemiological characteristics of TSCI patients in Xi'an, and preventive measures are suggested to be based on the characteristics of the different types of patients with TSCI and focused on high-risk groups.

Investigation of Suitable Templates for One-Pot-Synthesized Cu-SAPO-34 in NOx Abatement from Diesel Vehicle Exhaust.

The control of NOx emission from diesel vehicles is of great importance to the environment, and Cu-SAPO-34 is considered to be an effective catalyst for the abatement of NOx from diesel vehicles. Along with catalytic activity, hydrothermal stability is a key property for NOx abatement catalysts. The attack of Cu species and framework atoms by H2O may result in activity loss under both low/high temperature humid conditions, which are inevitable in practical application. Therefore, apart from good catalytic activity, hydrothermal stability under both low/high temperatures for Cu-SAPO-34 is also critical for NOx control in diesel vehicles. Three Cu-SAPO-34 samples were prepared by a one-pot hydrothermal method using propylamine, triethylamine, and morpholine, with Cu-TEPA (tetraethylenepentamine) as the cotemplate. The NH3-SCR activity and the effects of hydrothermal aging at 70 and 800 °C on these Cu-SAPO-34 samples were investigated. The type of cotemplate can affect the Si and Cu species in one-pot-synthesized Cu-SAPO-34 catalysts, so that the catalytic activity as well as the low/high temperature hydrothermal stability is affected by the choice of template. Generally speaking, Cu-SAPO-34 prepared using PA as cotemplate showed superior catalytic activity and hydrothermal stability under low/high temperatures compared with the other two catalysts, which makes PA a more suitable template for one-pot-synthesized Cu-SAPO-34 for use in NOx abatement from diesel vehicle exhaust.

Radiological and Clinical Differences between Tinavi Orthopedic Robot and O-Arm Navigation System in Thoracolumbar Screw Implantation for Reconstruction of Spinal Stability.

BACKGROUND Pedicle screw fixation is one of the most commonly used methods in spine surgery. We introduce a surgical robot system from China based on 3-dimensional fluoroscopy imaging and compare it with the commonly used O-arm navigation system. We study the differences in accuracy, safety, and clinical effect in auxiliary pedicle screw fixation. MATERIAL AND METHODS Patients who underwent thoracolumbar internal fixation in our hospital from 2017 to 2019 were divided into a robot and navigation group according to whether surgery was assisted by the Tinavi orthopedic robot or O-arm navigation system. Imaging data of patients were searched from the image system and accuracy of screw implantation was measured by Rampersaud A to D grade classification. Deviation sagittal, deviation transversal, and facet joint violation were also measured and calculated. RESULTS In total, 306 patients were included: 136 patients in the robot group with 760 screws implanted; 166 patients in the navigation group with 908 screws implanted. The accuracy of "perfect" and "clinically acceptable" pedicle screw implantation was 96.2% and 99.6%, respectively, in the robot group and 90.5% and 96.7%, respectively, in the navigation group, with a significant difference between the 2 groups (P<0.05). The sagittal and transversal deviations in the robot group were significantly less than those in the navigation group (P<0.05). CONCLUSIONS The Tinavi orthopedic robot can significantly improve surgical accuracy and safety of pedicle screw fixation, as compared with that of O-arm navigation technology, without increasing complications. It shows great potential in clinical application.

Early versus delayed decompression for traumatic cervical spinal cord injury: application of the AOSpine subaxial cervical spinal injury classification system to guide surgical timing.

PURPOSE: Application of AOSpine subaxial cervical spine injury classification system to explore the optimal surgical decompression timing for different types of traumatic cervical spinal cord injury (CSCI). METHODS: A single-center prospective cohort study was conducted that included patients with traumatic CSCIs (C3-C7) between February 2015 and October 2016. After enrollment, patients underwent either early (< 72 h after injury) or late (≥ 72 h after injury) decompressive surgery of the cervical spinal cord. Each group was divided into A0, A1-4, B, C/F4 and F1-3 subgroups. The primary outcomes were ordinal changes in the ASIA Impairment Scale (AIS) and the Spinal Cord Independence Measure III (SCIM version 3) at a 12-month follow-up. The secondary outcomes included length of hospital stay, postoperative neurological deterioration, other complications and mortality. RESULTS: A total of 402 patients were included. Of these, 187 patients underwent early decompression surgery, and 215 patients underwent delayed decompression surgery. Statistical results included the following comparisons of the early vs late groups: AIS improvement ≥ 1 grade (combined groups: P < 0.0001; A0: P = 0.554; A1-4: P = 0.084; B: P = 0.013; C/F4: P = 0.040; F1-3: P = 0.742); AIS improvement ≥ 2 grades, P = 0.003 for all groups; SCIM version 3 (combined groups: P < 0.0001; A0: P = 0.126; A1-4: P = 0.912; B: P = 0.006; C/F4: P = 0.111; F1-3: P = 0.875). CONCLUSION: Type A and F1-3 fractures are not required to undergo aggressive early decompression. Type B and type C/F4 fractures should receive early surgical treatment for better clinical outcomes. These slides can be retrieved under Electronic Supplementary Material.

Therapeutic efficacy of Transpedicular Intracorporeal cement augmentation with short segmental posterior instrumentation in treating osteonecrosis of the vertebral body: a retrospective case series with a minimum 5-year follow-up.

BACKGROUND: Transpedicular intracorporeal cement augmentation (TCA) with short segmental posterior instrumentation (SSPI), which provides an ideal immediate analgesic effect and long-term reconstructive stability, is thought to be a sensible advancement to the operative strategy in treating osteonecrosis of the vertebral body (ONV). However, long-term follow-up studies about the treatment are scarce. METHODS: Forty-six ONV patients (22 males and 24 females, mean age of 62.8 ± 7.11 years) underwent TCA with SSPI were retrospectively analyzed. During follow-up, clinical outcomes, such as the Visual Analogue Scale (VAS) score and the Oswestry Disability Index (ODI) score, were evaluated, as well as radiologic outcomes, such as the average vertebral height and kyphotic angle. RESULTS: A total of 36 patients completed a follow-up period of at least 5 years (mean follow-up period of 67 ± 4.2 months). Among them, seven patients experienced complications, i.e., pneumonia (2/36, 5.56%), screw loosening (2/36, 5.56%), moderate hematoma in the subcutaneous tissue (1/36, 2.78%), and cement leakage (2/36, 5.56%). Compared to the preoperative score, the mean VAS score was significantly reduced 6 months postoperatively (P < 0.05), and it concluded being virtually identical to the preoperative score (P > 0.05). The mean ODI score exhibited a comparable trend. Regarding the radiologic evaluation, the mean kyphotic angle and average vertebral body height were significantly corrected postoperatively (both P < 0.05). However, these radiological parameters were maximally ameliorated during the direct postoperative period and slowly deteriorated over time. CONCLUSION: The present study shows that TCA with SSPI may be only mildly effective for symptom relief and correction of kyphotic deformity during a relatively long follow-up, thus we do not recommend it for ONV.

Is percutaneous kyphoplasty the better choice for minimally invasive treatment of neurologically intact osteoporotic Kümmell's disease? A comparison of two minimally invasive procedures.

PURPOSE: The purpose of this study was to compare and evaluate the safety and efficacy of percutaneous vertebroplasty at a hyperextension position (PVPHP) and percutaneous kyphoplasty at a hyperextension position (PKPHP) for the treatment of osteoporotic Kümmell's disease. METHODS: This study was a retrospective, single-centre study. There were 35 patients with osteoporotic Kümmell's disease who were analyzed. Twenty-two of them underwent PVPHP and the other 13 patients underwent PKPHP from January 2013 to January 2015. The volume of bone cement injection and operation costs were compared. We compared the visual analogue score (VAS) and vertebral Cobb's angle at pre-operation, the second day after operation, and the final follow-up. We compared the Oswestry disability index (ODI) score at the pre-operation and the final follow-up. RESULTS: There were no significant differences in gender, age, course of disease, bone mineral density (BMD), and mean follow-up time between the two groups (P > 0.05). Regarding the costs of the operation, the PKPHP group was significantly higher than the PVPHP group (P < 0.05). Compared with the pre-operation (P < 0.05), the post-operative ODI score, VAS, and Cobb's angle of the two groups were improved significantly. Even though the correction of Cobb's angle in the PKPHP group was slightly better than the PVPHP position group, there were no significant differences between two groups (P > 0.05). At the final follow-up, the Cobb's angle was increased in both groups, but there was no significant difference (P > 0.05). There was no significant difference in the bone cement leakage rate between the two groups (P > 0.05). CONCLUSION: For the treatment of Kümmell's disease, PVPHP and PKPHP are both safe and effective, but PVPHP is more economical and can be considered a preferred method of treatment.

Comparison of Accuracy of Pedicle Screw Insertion Among 4 Guided Technologies in Spine Surgery.

BACKGROUND As an available new tool for spinal surgery, robotic technology holds great potential and has been demonstrated to have better clinical outcomes compared with traditional techniques. However, it has not been compared with other assisted tools for the treatment of lumbar degenerative disease. This article focused on studying such variances. MATERIAL AND METHODS A total of 176 pedicle screws were inserted in 39 patients using a spine robot (group 1), 134 screws were implanted in 28 patients using navigational template (group 2), 234 screws were implanted in 51 patients by O-arm-based navigation (group 3), and 346 screws were implanted in 72 patients by fluoroscopy-guided assistance (group 4). The screw position was evaluated using postoperative scans according to Rampersaud A to D classification, and other secondary data were also collected. RESULTS "Perfect" pedicle screw insertion (Grade A) was 90.34%, 91.79%, 84.19%, and 65.03% of groups 1-4, respectively. "Clinically acceptable" screw implantation (Grade A+B) was 94.32%, 95.52, 90.60%, and 78.03% in groups 1-4, respectively. Deviation sagittal (°) respectively was 3±9, 2±10, 4±7, and 10±8° in groups 1-4, respectively. Deviation transversal (°) screw insertion was 3±8, 3±7, 4±9, and 8±13° in groups 1-4, respectively. Statistical analysis showed group 1 had no significant difference in the accuracy of "Perfect and Clinical acceptable" as well as deviation sagittal or transversal, respectively, compared with groups 2 and 3 but not group 4. CONCLUSIONS Robotic-assistance technology no clear advantage in terms of accuracy compared to the navigation template or O-arm systems for screw implantation, but it significantly reduced adverse events, fluoroscopy time per screw, postoperative stay, and blood loss.