Neurological Analysis Based on the Terminal End of the Spinal Cord and the Narrowest Level of Injured Spine in Thoracolumbar Spinal Injuries

This study aimed to clarify neurological differences among the epiconus, conus medullaris, and cauda equina syndromes. Eighty-seven patients who underwent surgery for acute thoracolumbar spinal injuries were assessed. We defined the epiconus as the region from the terminal end of the spinal cord to the proximal 1.0 to 2.25 vertebral bodies, the conus medullaris as the region proximal to < 1.0 vertebral bodies, and the cauda equina as the distal part of the nerve roots originating from the spinal cord. On the basis of the distance from the terminal end of the spinal cord to the narrowest level of the spinal canal, the narrowest levels were ordered as follows: the epiconus followed by the conus medullaris and cauda equina. The narrowest levels were the epiconus in 22 patients, conus medullaris in 37 patients, and cauda equina in 25 patients. On admission, significantly more patients had a narrowed epiconus of Frankel grades A-C than a narrowed cauda equina. At the final follow-up, there were no significant differences in neurological recovery among those with epiconus, conus medullaris, or cauda equina syndrome. Anatomically classifying the narrowest lesion is useful for clarifying the differences and similarities among these three syndromes

Utilizing a Cortical Bone Trajectory Pedicle Screw for Lumbar Flexion-Distraction Injury

Spinal flexion-distraction injuries (FDIs) are unstable fractures, commonly located at the thoracolumbar junction. Management of FDIs often necessitates the use of posterior instrumentation and fusion, but long-segment instrumentation surgery decreases postoperative spinal mobility and increases the risk of junctional kyphosis and fracture. We report the case of a patient with FDI showing an L2 vertebral fracture, unilateral L2 pedicle fracture, and disruptions of the posterior ligamentous complex between L1 and L2. After open reduction using L1 and L2 pedicle screws with a conventional trajectory on the right side, a cortical bone trajectory (CBT) pedicle screw was used as an osteosynthesis screw for the fractured left pedicle. This procedure enabled successful single-level fusion. Follow-up radiological examination revealed good reduction and complete bone union. To the best of our knowledge, utilizing a CBT technique as an osteosynthesis screw in FDIs has not previously been described

Self-assembly of metal–organic polyhedra into supramolecular polymers with intrinsic microporosity

ゼリーのように柔らかい多孔性材料の開発 --ナノ空間を重合するという新合成手法を提案--. 京都大学プレスリリース. 2018-07-24.Designed porosity in coordination materials often relies on highly ordered crystalline networks, which provide stability upon solvent removal. However, the requirement for crystallinity often impedes control of higher degrees of morphological versatility, or materials processing. Herein, we describe a supramolecular approach to the synthesis of amorphous polymer materials with controlled microporosity. The strategy entails the use of robust metal–organic polyhedra (MOPs) as porous monomers in the supramolecular polymerization reaction. Detailed analysis of the reaction mechanism of the MOPs with imidazole-based linkers revealed the polymerization to consist of three separate stages: nucleation, elongation, and cross-linking. By controlling the self-assembly pathways, we successfully tuned the resulting macroscopic form of the polymers, from spherical colloidal particles to colloidal gels with hierarchical porosity. The resulting materials display distinct microporous properties arising from the internal cavity of the MOPs. This synthetic approach could lead to the fabrication of soft, flexible materials with permanent porosity

Ultrasound-Guided Peripheral Nerve Blocks Performed by Orthopedic Surgeons: A Retrospective, Multicenter Study in Akita Prefecture, Japan

The shortage of doctors is a societal problem, especially in rural areas such as Akita Prefecture, Japan. Therefore, it is not unusual in Akita for orthopedic surgeons to perform upper and lower limb surgeries under ultrasound-guided peripheral nerve blocks managed by the operators themselves. Multicenter studies of ultrasound-guided peripheral nerve blocks performed by orthopedic surgeons have not been reported. The purpose of this study was to clarify the safety and reliability of ultrasound-guided peripheral nerve blocks performed by orthopedic surgeons in Akita. A total of 1,674 upper extremity surgery cases operated under ultrasound-guided peripheral nerve blocks at 8 hospitals in Akita prefecture from April 2016 to April 2018 were investigated retrospectively. These blocks were performed by a total of 37 orthopedic surgeons, including senior surgeons and residents. In 321 of the 1,674 cases (19%), local anesthetics were added to the surgical field. Two cases with special factors were converted to general anesthesia. There were 2 cases of complications associated with the nerve block, but they were all transient and recovered promptly. The block site and the hospital where the block was performed showed a significant relationship with the addition of local anesthetics to the surgical site (P<0.001). Surgery time, age at surgery, and surgical site showed no significant relationships with the addition of local anesthetics. The volume of the anesthetic used for the nerve block showed a significant inverse relationship with the addition of local anesthetics (P=0.040). Many orthopedic surgeons in Akita prefecture began to perform ultrasound-guided peripheral nerve blocks, which had a reliable anesthesia effect with no noticeable complications, whether performed by residents or senior orthopedic surgeons, and this is a useful anesthetic technique for orthopedic surgeons

Pore-networked gels : permanently porous ionic liquid gels with linked metal-organic polyhedra networks

Porous liquids (PLs) are attractive materials because of their capability to combine the intrinsic porosity of microporous solids and the processability of liquids. Most of the studies focus on the synthesis of PLs with not only high porosity but also low viscosity by considering their transportation in industrial plants. However, a gap exists between PLs and solid adsorbents for some practical cases, where the liquid characteristics and mechanical stability without leakage are simultaneously required. Here, we fill in this gap by demonstrating a new concept of pore-networked gels, in which the solvent phase is trapped by molecular networks with accessible porosity. To achieve this, we fabricate a linked metal–organic polyhedra (MOPs) gel, followed by exchanging the solvent phase with a bulky liquid such as ionic liquids (ILs); the dimethylformamide solvent trapped inside the as-synthesized gel is replaced by the target IL, 1-butyl-3-methylimidazolium tetrafluoroborate, which in turn cannot enter MOP pores due to their larger molecular size. The remaining volatile solvents in the MOP cavities can then be removed by thermal activation, endowing the obtained IL gel (Gel_IL) with accessible microporosity. The CO2 capacities of the gels are greatly enhanced compared to the neat IL. The exchange with the IL also exerts a positive influence on the final gel performances such as mechanical properties and low volatility. Besides ILs, various functional liquids are shown to be amenable to this strategy to fabricate pore-networked gels with accessible porosity, demonstrating their potential use in the field of gas adsorption or separation