Fine Structure and Electrochemical Performance Investigations of Spherical LiMn0.6Fe0.4PO4/C Cathode Material Synthesized via a Spray-Drying Route at Various Calcination Temperatures.

LiMnxFe1-xPO4/C is characterized by excellent multiplicative performance and high operating voltage, and as a type of cathode material, it has a high electronic conductivity and thus has received much attention. In this paper, carbon-coated LiMn0.6Fe0.4PO4/C was synthesized using glucose + PEG2000 as the carbon source by wet sanding and spray-drying. The experimental results show that the use of sanding and the spray-drying method can make the particle size distribution of LiMn0.6Fe0.4PO4/C powder more uniform. The initial discharge specific capacity of the LiMn0.6Fe0.4PO4/C battery was 144.3 mA h g-1, and after 100 cycles at 1 C current, the discharge specific capacity of the battery remained at 128.2 mA h g-1 with a cycling efficiency of 94.3%. At the same time, the oxidation states and coordination environments of the elements Fe and Mn were elucidated by X-ray absorption fine structure spectroscopy. And the ex-Fe-MS was tested under different charging and discharging conditions. The sample optimized by the orthogonal test has good cycle stability and multiplication performance.

Review on Layered Manganese-Based Metal Oxides Cathode Materials for Potassium-Ion Batteries: From Preparation to Modification.

Potassium-ion battery is rich in resources and cheap in price, in the era of lithium-ion battery commercialization, potassium-ion battery is the most likely to replace it. Based on the classification and summary of electrode materials for potassium-ion batteries, this paper focuses on the introduction of manganese-based oxide KxMnO2. The layered KxMnO2 has a large layer spacing and can be embedded with large size potassium-ions. This paper focuses on the preparation and doping of manganese-based cathode materials for potassium-ion batteries, summarizes the main challenges of KxMnO2-based cathode materials in the current stage of research and further looks into its future development direction.

Avulsion fracture of the anterior superior iliac crest following autograft for anterior lumbar fusion: case report and literature review.

Avulsion fracture of the anterior superior iliac crest (ASIC) following autogenous bone grafting for anterior lumbar fusion (ALF) is an extremely rare complication. We describe a very rare case of avulsion fracture of the ASIC following autograft for ALF in a revision surgery for treating lumbar tuberculosis. A 68-year-old woman with lumbar tuberculosis underwent posterior debridement and posterior iliac crest bone graft fusion; however, her lumbar tuberculosis recurred 9 months after surgery. She then underwent a lumbar revision surgery, including removal of the posterior instrumentation and debridement, followed by anterior L2 corpectomy, debridement, anterior left iliac crest bone graft fusion, and internal fixation. When walking for the first time on postoperative day 3, she experienced a sharp, sudden-onset pain in the anterior iliac crest harvest area. X-ray revealed an avulsion fracture of the ASIC. Considering her failure to respond to conservative treatment for one week and large displacement of the fracture ends, an open reduction and internal fixation surgery was scheduled. Her pain symptoms were significantly relieved after the operation. Although rare, fracture of the ASIC following autograft for ALF should not be ignored. Fracture of the ASIC is usually treated conservatively. Additional surgical treatment is required only when intractable pain fails to respond to conservative treatment or when there is a large displacement of fracture ends that are not expected to heal spontaneously.

Comparison of instrumented and stand-alone lateral lumbar interbody fusion for lumbar degenerative disease: a systematic review and meta-analysis.

BACKGROUND: Both instrumented and stand-alone lateral lumbar interbody fusion (LLIF) have been widely used to treat lumbar degenerative disease. However, it remains controversial as whether posterior internal fixation is required when LLIF is performed. This meta-analysis aims to compare the radiographic and clinical results between instrumented and stand-alone LLIF. METHODS: PubMed, EMBASE and Cochrane Collaboration Library up to March 2023 were searched for studies that compared instrumented and stand-alone LLIF in the treatment of lumbar degenerative disease. The following outcomes were extracted for comparison: interbody fusion rate, cage subsidence rate, reoperation rate, restoration of disc height, segmental lordosis, lumbar lordosis, visual analog scale (VAS) scores of low-back and leg pain and Oswestry Disability Index (ODI) scores. RESULTS: 13 studies involving 1063 patients were included. The pooled results showed that instrumented LLIF had higher fusion rate (OR 2.09; 95% CI 1.16-3.75; P = 0.01), lower cage subsidence (OR 0.50; 95% CI 0.37-0.68; P < 0.001) and reoperation rate (OR 0.28; 95% CI 0.10-0.79; P = 0.02), and more restoration of disc height (MD 0.85; 95% CI 0.18-1.53; P = 0.01) than stand-alone LLIF. The ODI and VAS scores were similar between instrumented and stand-alone LLIF at the last follow-up. CONCLUSIONS: Based on this meta-analysis, instrumented LLIF is associated with higher rate of fusion, lower rate of cage subsidence and reoperation, and more restoration of disc height than stand-alone LLIF. For patients with high risk factors of cage subsidence, instrumented LLIF should be applied to reduce postoperative complications.

Crystalline Structure and Thermal Stability of an Unknown ZIF-L300 Phase.

In recent years, the synthesis, crystalline structure, and applications of zeolite imidazole frameworks (ZIFs) have attracted extensive attention. Since the ZIF-L phase was synthesized, a new phase was observed during the heating process, but its crystal structure is unknown. The unknown new phase, which was named ZIF-L300 in this study, was confirmed again. In this study, the X-ray powder diffraction technique and Rietveld refinement were used to solve the crystalline structure of the unknown ZIF-L300 phase. The results demonstrate that ZIF-L300 has the same chemical formula (ZnC8N4H10) as in ZIF-8 and belongs to a hexagonal structure with a space group of P61. The lattice parameters have been determined as follows: a = b = 8.708(7) Å, c = 24.195(19) Å, α = ß = 90°, and γ = 120°. The X-ray absorption fine structure (XAFS) technique was also used to extract the local atomic structures. The in situ X-ray diffraction (XRD) technique was used to monitor the structural evolution of the as-prepared ZIF-L in a temperature range from room temperature to 600 °C. The results show that the sample experiences a change process from the initial ZIF-L orthorhombic phase (<210 °C), to the ZIF-L300 hexagonal phase (∼300 °C), then to an amorphous phase (∼390 °C), and finally to a zincite ZnO phase (>420 °C). These sorts of structural information are helpful to the application of ZIF materials and enrich the knowledge of the thermal stability of ZIF materials.

Properties of the "Z"-Phase in Mn-Rich P2-Na0.67 Ni0.1 Mn0.8 Fe0.1 O2 as Sodium-Ion-Battery Cathodes.

P2 layered oxides have attracted more and more attention as cathode materials of high-power sodium-ion batteries (SIBs). During the charging process, the release of sodium ions leads to layer slip, which leads to the transformation of P2 phase into O2 phase, resulting in a sharp decline in capacity. However, many cathode materials do not undergo P2 -O2 transition during charging and discharging, but form a "Z" phase. It is proved that the iron-containing compound Na0.67 Ni0.1 Mn0.8 Fe0.1 O2 formed the "Z" phase of the symbiotic structure of the P phase and O phase during high-voltage charging through ex-XRD and HAADF-STEM. During the charging process, the cathode material undergoes a structural change of P2 -OP4 -O2 . With the increase of charging voltage, the O-type superposition mode increases to form an ordered OP4 phase, and the P2 -type superposition mode disappears after further charging to form a pure O2 phase. 57 Fe-Mössbauer spectroscopy revealed that no migration of Fe ions is detected. The O-Ni-O-Mn-Fe-O bond formed in the transition metal MO6 (M = Ni, Mn, Fe) octahedron can inhibit the elongation of the Mn-O bond and improve the electrochemical activity so that P2-Na0.67 Ni0.1 Mn0.8 Fe0.1 O2 has an excellent capacity of 172.4 mAh g-1 and a coulombic efficiency close to 99% at 0.1C.

A polycrystalline diamond micro-detector for X-ray absorption fine-structure measurements.

The microminiaturization of detectors used to record the intensity of X-ray beams is very favorable for combined X-ray experimental techniques. In this paper, chemical-vapor-deposited (CVD) polycrystalline diamond film was used to fabricate a micro-detector owing to its well controlled size, good thermostability, and appropriate conductivity. The preparation process and the main components of the CVD diamond micro-detector are described. The external dimensions of the packaged CVD diamond micro-detector are 15 mm × 7.8 mm × 5.8 mm. To demonstrate the performance of the detector, K-edge X-ray absorption fine-structure (XAFS) spectra of Cr, Fe, Cu, and Se foils were collected using the CVD diamond micro-detector and routine ion chamber. These XAFS measurements were performed at beamline 1W2B of Beijing Synchrotron Radiation Facility, covering an energy range from 5.5 to 13.5 keV. By comparison, it can be seen that the CVD diamond micro-detector shows a more excellent performance than the routine ion-chamber in recording these XAFS spectra. The successful application of the CVD diamond micro-detector in XAFS measurements shows its feasibility in recording X-ray intensity.

Hydrothermal Synthesis and Structures of Unknown Intermediate Phase Zn(HCO3)2·H2O Nanoflakes and Final ZnO Nanorods.

The formation mechanism of nanoparticles is of great significance for the controllable synthesis, structural design, and performance optimization of nanomaterials. In this paper, an economical hydrothermal method was used to synthesize zinc oxide (ZnO) nanorods. X-ray diffraction, X-ray absorption fine structure, and small-angle X-ray scattering techniques were used to probe the structural changes. Scanning electron microscopy and high-resolution transmission electron microscopy were used to observe the morphologies of the products. A self-designed in situ temperature-pressure sample cell was used to control the hydrothermal conditions. The results demonstrate that an unknown intermediate phase, Zn(HCO3)2·H2O, was first formed at 50 °C, having a morphology of nanoflakes with a average thickness of about 35 nm. The intermediate phase Zn(HCO3)2·H2O was determined to have a monoclinic structure with space group P1211 and the following lattice parameters: a = 11.567 Å, b = 3.410 Å, c = 5.358 Å, ß = 96.0011°, and Z = 2. After a hydrothermal temperature of 140 °C, CO2 and H2O were evaporated from the Zn(HCO3)2·H2O intermediate product and the ZnO nanorods with a wurtzite structure were formed. The final ZnO nanorods have an average diameter of about 45 nm and an average length of about 2 µm. The axial direction of the ZnO nanorods is the [001] crystallographic direction. By virtue of understanding the formation mechanism, this work is helpful for the controllable synthesis of ZnO nanoparticles.

Red mud regulates arsenic fate at acidic pH via regulating arsenopyrite bio-oxidation and S, Fe, Al, Si speciation transformation.

Red mud (RM) as waste of industrial aluminum production is piling up in huge ponds. RM could be a cost-effective adsorbent for heavy metals, but adsorption is vulnerable to pH changes, metal ions speciation and the occurrence of iron bearing minerals. In this study, the precipitation and elemental speciation transformation relevant to arsenic fate in responding to the addition of RM during arsenopyrite bio-oxidation by Sulfobacillus thermosulfidooxidans was investigated. The results show that the addition of RM significantly changed the arsenic precipitation and the solution chemistry and thus affected the arsenopyrite bio-oxidation and arsenic fate. An addition of a small amount (≤ 4 g/L) of RM substantially promoted arsenopyrite bio-oxidation with formation of SiO2 @ (As, Fe, Al, Si) spherical nanoparticles that can enhance the stability of the immobilized arsenic. The SiO2-based spherical nanoparticles precipitate was mainly composed of jarosites, amorphous ferric arsenate and crystalline scorodite, and its formation were controlled by Fe3+ concentration and solution pH. An addition of increased amount of RM (≥ 6 g/L) resulted in a significant increase of the solution pH and a decrease in the Fe2+ bio-oxidation activity, and spherical nanoparticles were not formed. Consequently, the dissolution of arsenopyrite was inhibited and the release of arsenic was blocked. This study suggests the applicability of RM in mitigation of arsenic pollution from bio-oxidation of As-bearing sulfide minerals.

[Risk factors analysis of adjacent fractures after percutaneous vertebroplasty for osteoporotic vertebral compression fracture].

OBJECTIVE: To investigate the risk factors of adjacent fractures after percutaneous vertebroplasty (PVP) for osteoporotic vertebral compression fracture (OVCF). METHODS: A total of 2 216 patients who received PVP due to symptomatic OVCF between January 2014 and January 2017 and met the selection criteria were selected as study subjects. The clinical data was collected, including gender, age, height, body mass, history of smoking and drinking, whether the combination of hypertension, diabetes, coronary arteriosclerosis, chronic obstructive pulmonary disease (COPD), bone mineral density, the number of fractured vertebrae, the amount of cement injected into single vertebra, the cement leakage, and whether regular exercise after operation, whether regular anti-osteoporosis treatment after operation. Firstly, single factor analysis was performed on the observed indicators to preliminarily screen the influencing factors of adjacent fractures after PVP. Then, logistic regression analysis was carried out for relevant indicators with statistical significance to screen risk factors. RESULTS: All patients were followed up 12-24 months, with an average of 15.8 months. Among them, 227 patients (10.24%) had adjacent fractures. The univariate analysis showed that there were significant differences between the fracture group and non-fracture group in age, gender, preoperative bone density, history of smoking and drinking, COPD, the number of fractured vertebrae and the amount of bone cement injected into the single vertebra, as well as regular exercise after operation, regular anti-osteoporosis treatment after operation ( P<0.05). Further multivariate logistic regression analysis showed that the elderly and female, history of smoking, irregular exercise after operation, irregular anti-osteoporosis treatment after operation, low preoperative bone density, large number of fractured vertebrae, and small amount of bone cement injected into the single vertebra were risk factors for adjacent fractures after PVP in OVCF patients ( P<0.05). CONCLUSION: The risk of adjacent fractures after PVP increases in elderly, female patients with low preoperative bone mineral density, large number of fractured vertebrae, and insufficient bone cement injection. The patients need to quit smoking, regular exercise, and anti-osteoporosis treatment after PVP.

Esophageal perforation following pedicle screw placement for the treatment of upper thoracic spinal tuberculosis: a case report and review of the literature.

BACKGROUND: The technique of posterior pedicle screw fixation has already been widely applied in the treatment of upper thoracic spinal tuberculosis. However, lesions of tuberculosis directly invade the vertebrae and surrounding soft tissues, which increases the risk of esophageal perforation induced by the posterior pedicle screw placement. Herein, we report the first case of esophageal perforation following pedicle screw placement in the upper thoracic spinal tuberculosis, and describe the underlying causes, as well as the treatment and prognosis. CASE PRESENTATION: A 48-year-old female patient with upper thoracic spinal tuberculosis presented sputum-like secretions from the wound after she was treated with one-stage operation through the posterolateral approach. Endoscopy was immediately conducted, which confirmed that the patient complicated with postoperative esophageal perforation caused by screws. CT scan showed that the right screw perforated the anterior cortex of the vertebrae and the esophagus at the T4 level. Fortunately, mediastinal infection was not observed. The T4 screw was removed, Vacuum Sealing Drainage (VSD) was performed, and jejunum catheterization was used for enteral nutrition. After continuous treatment with sensitive antibiotics for 2.5 months and 5 times of VSD aspiration, the infected wound recovered gradually. With 18-month follow-up, the esophagus healed well, without symptoms of dysphagia and stomach discomfort, and CT scan showed that T2-4 had complete osseous fusion without sequestrum. CONCLUSION: Tuberculosis increases the risk of postoperative esophageal perforation in a certain degree for patients with upper thoracic tuberculosis. The damages to esophagus during the operation should be prevented. The screws with the length no more than 30 mm should be selected. Moreover, close monitoring after operation should be conducted to help the early identification, diagnosis and treatment, which could help preventing the adverse effects induced by the delayed diagnosis and treatment of esophageal perforation.

Spinal Epidural Hematoma After Percutaneous Kyphoplasty: Case Report and Literature Review.

OBJECTIVE: To present the case of a patient on long-term anticoagulants who developed acute spinal epidural hematoma (SEH) after percutaneous kyphoplasty (PKP) without signs of major cement extravasation to the spinal canal. METHODS: A 64-year-old woman with long-term oral antiplatelet drugs underwent the L1 PKP. Immediately after the operation, the back pain improved significantly without neurological deficit. However, 12 hours later, she developed progressive weakness of the bilateral lower limbs. No intraspinal cement leakage was obvious on the postoperative lumbar radiograph and computed tomography. RESULTS: An emergency MRI examination revealed a high signal aggregation in front of the spinal cord from T12 to L1, indicating spinal cord compression. The SEH was verified and removed during the laminectomy from T12-L1. Following the decompression surgery, the neurological deficit of the lower limbs improved. On follow-up after 6 months, the muscle strength of the bilateral lower limbs had returned to normal. CONCLUSION: For the patient with long-term oral antiplatelet drugs or coagulation malfunction, the transpedicle approach or that via the costovertebral joint with a smaller abduction angle is recommended to reduce the risk of injury to the inner wall of the pedicle. For progressive aggravation of neurological dysfunction after surgery, SEH formation should be suspected despite the absence of intraspinal bone cement leakage. Secondary emergency decompression should be considered to avoid permanent damage to spinal cord nerve function caused by continuous compression.

Bismuth-iron-based precursor: preparation, phase composition, and two methods of thermal treatment.

Bismuth ferrite (BiFeO3) is a promising Bi-based perovskite-type material, which is multiferroic due to the coexistence of anti-ferromagnetism and ferroelectricity. During the preparation of pure BiFeO3 nanoparticles, however, the phase structures and species of bismuth-iron-based precursor (BFOH) were still unclear, and so related precursors were prepared. X-ray diffraction, Raman, Fourier transform infrared, and X-ray absorption near-edge structure techniques were used to probe the phase structure and species of the precursors. It was found that the precursor BFOH is composed of Bi6O6(NO3)4(OH)2·2H2O, Bi6O5(NO3)5(OH)3·3H2O, Fe(OH)3, and α-Bi2O3. Calcination treatment and hydrothermal synthesis were used to prepare the pure BiFeO3 phase from the precursor BFOH. The calcination temperature was optimized as 400 °C for preparation of the pure BiFeO3 phase. Meanwhile, hydrothermal conditions for the synthesis of the pure BiFeO3 phase were also optimized as follows: the reaction solution was the mixture solution of Bi(NO3)3·5H2O and Fe(NO3)3·9H2O with cetyltrimethyl ammonium bromide (CTAB) as the surfactant and KOH as the mineralizer; the hydrothermal synthesis was performed at 180 °C for 48 h; the concentration of KOH should be at least 3 M; and the surfactant CTAB can be used to regulate the morphology of the as-prepared BiFeO3 nanoparticles. From the point of view of the microstructure, BiFeO3 nanoparticles prepared by calcination or hydrothermal methods have no notable differences. A formation mechanism from the precursor BFOH to the BiFeO3 product is proposed. By providing an understanding of the precursors, this work is very helpful in the synthesis of bismuth-iron-based nanoparticles.

Modulating the Hydrothermal Synthesis of Co3O4 and CoOOH Nanoparticles by H2O2 Concentration.

The formation process and product control are very important in material synthesis. In this study, a facile one-pot hydrothermal method was used to prepare Co3O4 and CoOOH. H2O2 was used to modulate the formation process and control the final product by changing its concentration. The crystalline structures and morphologies of the as-prepared products were characterized by X-ray diffraction (XRD), Raman spectra, and scanning electron microscopy (SEM) techniques. It was found that the concentration of H2O2 influenced not only the phase of the final products but also their morphologies. The influences of H2O2 concentration on the precursor formation and the reaction path have been revealed. At a low concentration of H2O2 (5 wt %), the formed precursor is Co(CO3)0.5(OH)·0.11H2O, which can be directly transformed into Co3O4 upon increasing the hydrothermal time. At a medium concentration (15-20 wt %), the formed precursor and the final product are all CoOOH. At a high concentration (30 wt %), the formed precursor is CoOOH, and the final product is Co3O4. H2O2 plays the role of oxidant agent at the initial stage or reducing agent at the subsequent stage. This study offers a H2O2-concentration modulating method for the formation of Co3O4 and CoOOH.

One-stage Surgical Management for Lumbar Brucella Spondylitis by Posterior Debridement, Autogenous Bone Graft and Instrumentation: A Case Series of 24 Patients.

STUDY DESIGN: Clinical case series. OBJECTIVE: The aim of this study was to explore the efficacy and safety of one-stage debridement, autogenous bone graft, and instrumentation for lumbar brucella spondylitis (LBS) via a posterior approach. SUMMARY OF BACKGROUND DATA: Reports on LBS are sporadic, and the therapeutic effect and safety of surgical interventions have not been assessed in clinical studies. METHODS: Between January 2012 and January 2014, 24 consecutive patients with symptomatic LBS who underwent a one-stage operation that combined debridement, autogenous bone graft, and instrumentation via a posterior approach were enrolled. Back pain was measured using the visual analog scale (VAS). The neurological status was evaluated with the American Spinal Injury Association (ASIA) scale. Bone healing was evaluated based on postoperative plain x-ray or computed tomography. RESULTS: All cases were followed up for an average of 14.3 + 3.5 months. The VAS scores were significantly improved at every follow-up interval. An improvement of at least one grade level was observed in the ASIA score of each patient. The average time of bone fusion was 6.8 + 1.6 months. Significant improvements of the average segmental Cobb angle was observed from a preoperative value of 18.4° + 4.6° to a last follow-up value of 21.1°â€Š±â€Š3.7°. At the last follow up, the titers of antibodies against the standard tube agglutination test, erythrocyte sedimentation rate, and C-reactive protein were negative for all patients. CONCLUSION: For LBS, systemic antibrucellosis chemotherapy is the cornerstone of treatment. When cauda equine syndrome, radiculopathy, spinal instability, and severe back pain caused by extradural nonabsorbable abscess or progressive collapse are present, surgical intervention is inevitable. One-stage debridement, autogenous bone graft, and instrumentation via a posterior approach could represent an alternative treatment for LBS, and the efficacy and safety of these techniques are satisfactory. LEVEL OF EVIDENCE: 4.

[Effectiveness comparison between two operations in treatment of unstable type Kümmell's disease].

Objective: To compare the effectiveness between short segmental fixation combined with vertebroplasty (SSF+VP) and short segmental pedicle screw fixation combined with bone graft (SSF+BG) in the treatment of unstable type Kümmell's disease so as to provide a reference for the selection of the surgical method. Methods: Between March 2013 and February 2015, 48 patients with unstable type Kümmell's disease who were in accordance with the inclusive criteria were included in the study. SSF+VP were used in 25 cases (SSF+VP group) and SSF+BG in 23 cases (SSF+BG group). There was no significant difference in gender, age, disease duration, bone mineral density, fracture segment, and preoperative visual analogue scale (VAS), Oswestry disability index (ODI), and kyphotic Cobb angle between 2 groups ( P>0.05). The operation time and complications related to operation were recorded; the effectiveness was evaluated by VAS, ODI, and kyphotic Cobb angle. Results: The operation time was (107.7±18.8) minutes in SSF+VP group and was (113.7±22.4) minutes in SSF+BG group, showing no significant difference between 2 groups ( t=-1.045, P=0.302). Bone cement leakage occurred in 6 cases of SSF+VP group, and incision delayed healing occurred in 1 case of SSF+BG group. All patients achieved bone graft fusion on X-ray films. The bone graft fusion time was (15.1±1.3) weeks in SSF+VP group and (15.7±1.8) weeks in SSF+BG group, showing no significant difference between 2 groups ( t=-1.361, P=0.180). The VAS, ODI, and kyphotic Cobb angle at immediate after operation and at last follow-up were significantly lower than preoperative ones ( P<0.05). The VAS, ODI, and kyphotic Cobb angle had no significant difference between at immediate and at last follow-up in SSF+VP group ( P>0.05). In SSF+BG group, VAS at last follow-up was significantly lower than that at immediate after operation ( P<0.05), but no significant difference was found in kyphotic Cobb angle and ODI ( P>0.05). SSF+VP group was significantly better than SSF+BG group in VAS at immediate after operation ( P<0.05), but SSF+BG group was significantly better than SSF+VP group at last follow-up ( P<0.05). There was no significant difference in kyphotic Cobb angle and ODI between 2 groups at immediate after operation and at last follow-up ( P>0.05). Conclusion: SSF+BG can achieve satisfactory effectiveness in the treatment of unstable type Kümmell's disease, and it has the advantages of good bony healing, obvious improvement of pain, and low complication incidence when compared with SSF+VP.

Biomechanical Analysis of a Novel Prosthesis Based on the Physiological Curvature of Endplate for Cervical Disc Replacement.

STUDY DESIGN: Biomechanical analysis of a novel prosthesis based on the physiological curvature of endplate was performed. OBJECTIVE: To compare the biomechanical differences between a novel prosthesis based on the physiological curvature of the endplate and the Prestige LP prosthesis after cervical disc replacement (CDR). SUMMARY OF BACKGROUND DATA: Artificial disc prostheses have been widely used to preserve the physiological function of treated and adjacent motion segments in CDR, while most of those present a flat surface instead of an arcuate surface which approximately similar to anatomic structures in vivo. We first reported a well-designed artificial disc prosthesis based on the physiological curvature of the endplate. METHODS: Three motion segments of 24 ovine cervical spines (C2-5) were evaluated in a robotic spine system with axial compressive loads of 50N. Testing conditions were as follows: 1) intact, 2) C3-4 CDR with artificial disc prosthesis based on the physiological curvature of the endplate, and 3) C3-4 CDR with the Prestige LP prosthesis. The range of motion (ROM) and the pressures on the inferior surface of the two prostheses were recorded and analyzed. RESULTS: As compared to the intact state, the ROM of all three segments had no significant difference in the replacement group. Additionally, there was no significant difference in ROM between the two prostheses. The mean pressure on the novel prosthesis was significantly less than the Prestige LP prosthesis. CONCLUSION: ROM in 3 groups (intact group, CDR group with novel prosthesis and CDR group with Prestige LP) showed no significant difference. The mean pressure on the inferior surface of the novel prosthesis was significantly lower than the Prestige LP prosthesis. Therefore, the novel artificial disc prosthesis is feasible and effective, and can reduce the implant-bone interface pressure on the endplate, which may be one possible reason of prosthesis subsidence.

Tuberculous Spondylitis Following Kyphoplasty: A Case Report and Review of the Literature.

Tuberculous spondylitis of the augmented vertebral column following percutaneous vertebroplasty or kyphoplasty has rarely been described. We report an unusual case of tuberculous spondylitis diagnosed after percutaneous kyphoplasty (PKP). A 61-year-old woman presented to our institution complaining of back pain following a fall 7 days before. Radiologic studies revealed an acute osteoporotic compression L1 fracture. The patient denied history of pulmonary tuberculosis (TB) and there were no signs of infection. The patient was discharged from hospital 4 days after undergoing L1 PKP with a dramatic improvement in her back pain. Two years later, the patient was readmitted with a 1 year history of recurrent back pain. Imaging examinations demonstrated long segmental bony destruction involving L1 vertebra with massive paravertebral abscess formation. The tentative diagnosis of tuberculous spondylitis was made, after a serum T-SPOT. The TB test was found to be positive. Anterior debridement, L1 corpectomy, decompression, and autologous rib graft interposition, and posterior T8-L4 instrumentation were performed. The histologic examination of the resected tissue results confirmed the diagnosis of spinal TB. Anti-TB medications were administered for 12 months and the patient recovered without sequelae. Spinal TB and osteoporotic vertebral compression fractures are similar clinically and radiologically. Spinal surgeons should consider this disease entity to avoid misdiagnosis or complications. Early surgical intervention and anti-TB treatment should be instituted as soon as the diagnosis of spinal TB after vertebral augmentation is made.