[Oblique Lumbar Interbody Fusion Combined With 4-Screw Fixation for Treating Two-Level Degenerative Lumbar Diseases:A Finite Element Study].

Objective To demonstrate the feasibility of oblique lumbar interbody fusion (OLIF) combined with 4-screw fixation for treating two-level lumbar degenerative diseases.Methods An intact finite element model of L3-S1 (M0) was constructed and validated.Then,we constructed the M1 model by simulating OLIF surgery at L3/4 and L4/5 segments on the M0 model.By attachment of posterior 4-screw or 6-screw fixation to the M1 model,three 4-screw fixation models (M2-M4) and one 6-screw fixation model (M5) were established.The segmental and overall range of motion (ROM) and the peak von Mises stresses of superior endplate,cage,and posterior screw-rod were investigated under each implanted condition.Results Under the motion modes of forward flexion,backward extension,bilateral (left and right) flexion,and left and right rotation,the L3/4 ROM of M2 model and L4/5 ROM of M3 model increased,while the L3/4 and L4/5 ROM of M4 and M5 models significantly decreased compared with those of M1 model.Under all motion modes,the L4 superior endplate in M2 model and the L5 superior endplate in M3 model showed the maximum peak von Mises stress,and the peak von Mises stresses of L4 and L5 superior endplates in M4 and M5 models were close.The L3/4 cage in M2 model and the L4/5 cage in M3 model showcased the largest peak von Mises stress,and the peak von Mises stresses of cages in M4 and M5 models were close.The peak stresses of internal fixation in M2-M5 models were close.Conclusion Four-screw fixation can replace 6-screw fixation in the OLIF surgery for treating two-level degenerative lumbar diseases.

[Unilateral interlaminar approach 270° circular spinal canal decompression under the iLESSYS Delta for the treatment of lumbar spinal stenosis in the elderly].

OBJECTIVE: To investigate the clinical effect of unilateral interlaminar approach 270° circular spinal canal decompression under the Interlaminar Endoscopic Surgical System(iLESSYS) Delta for the treatment of lumbar spinal stenosis (LSS) in the elderly. METHODS: Total of 29 patients with LSS treated with the iLESSYS Delta from December 2018 to January 2021 were retrospectively analyzed, including 12 males and 17 females with an average age of (71.52±10.82) years old ranging from 63 to 83 years old. All patients had definite intermittent claudication, mainly neurogenic symptoms of both lower limbs. All patients had single-level spinal stenosis, including L3,4 5 cases, L4,5 21 cases, and L5S1 3 cases. Visual analogue scale (VAS), Oswestry Disability Index (ODI) and modified Macnab assessment criteria were used to evaluate pain, low back pain dysfunction index and clinical efficacy, respectively. RESULTS: All 29 cases were successfully completed. The operation time was (73.45±5.89) min, the intraoperative blood loss was (9.93±0.83) ml, the hospital stay was (4.03±0.41) days, and the follow-up was more than 12 months. The VAS scores of low back pain before surgery and 1 day, 1 month, 3 months, 1 year after surgery were 2.31±0.88, 1.45±0.62, 1.21±0.61, 1.10±0.55, 1.03±0.49;VAS of leg pain were 6.48±0.49 0.56, 1.97±0.61, 1.31±0.59, 1.17±0.59, 1.10±0.55;ODI scores were 38.41±2.74, 18.14±1.17, 5.17±0.53, 5.07±0.45, 4.90±0.48;low back and leg pain VAS score and ODI score have statistically significant differences between preoperative and postoperative follow-up time points (P<0.05). The MacNab efficacy evaluation at 1-year follow-up:excellent in 22 cases, good in 5 cases and fair in 2 cases. CONCLUSION: The clinical effect of unilateral interlaminar approach 270° circular spinal canal decompression under the iLESSYS Delta for the treatment of lumbar spinal stenosis in the elderly is satisfactory, with the advantages of less trauma and less bleeding, large microscopic operation space, sufficient decompression, and ideal post-operative recovery, and at the same time, it can minimize the damage to the stable structure of the lumbar spine, which is an ideal surgical method for the treatment of elderly lumbar spinal stenosis.

Multifunctional Drugs-Loaded Carbomol Hydrogel Promotes Diabetic Wound Healing via Antimicrobial and Immunoregulation.

Diabetic wound healing poses a significant clinical dilemma. Bacterial infection and immune dysregulation are the predominant reasons. However, conventional wound dressings with a single treatment approach often limit therapeutic efficacy and continue working with difficulty. These limitations cause high treatment failure for diabetic wounds. In this study, we developed a multiple drug-loaded carbomer hydrogel containing Que/Van/Rif (QVR-CBMG) for the simultaneous treatment of infection and immune dysregulation. Honeycomb-like QVR-CBMG hydrogel exhibits excellent abilities to eliminate bacterial infection and biofilms in vitro. Moreover, QVR-CBMG hydrogel possesses an immunomodulatory capacity via affecting the Sirt3/SOD2 signaling pathway to promote M2 macrophages. Furthermore, QVR-CBMG hydrogel effectively promotes wound healing in diabetic rats through several mechanisms. The multidrug-loaded wound dressing not only eliminates bacterial infection and facilitated angiogenesis but also promotes collagen deposition and remodulates the local immune microenvironment in the areas of wounds. In summary, this synthetic strategy to eliminate infection and regulate immune disorders has potential translational value for the prevention and management of diabetic wounds.

Biomechanical evaluation of two-level oblique lumbar interbody fusion combined with posterior four-screw fixation：A finite element analysis.

OBJECTIVE: By constructing the three-dimensional finite element model of two-level OLIF lumbar spine, the aim of this study was to demonstrate the feasibility and effectiveness of posterior four-screw fixation for treatment of two-level lumbar degenerative diseases from the perspective of biomechanics. METHODS: An intact L3-S1 segment nonlinear lumbar finite element model (M0) was constructed from the CT scanning data of a healthy adult. After verification, two-level OLIF procedure were simulated, and three patterns of finite element analysis models were constructed: two-level stand-alone OLIF group (M1), two-level OLIF + four-screw fixation group (M2) and two-level OLIF + six-screw fixation group (M3). Range of motion, stress of the cage, and stress of fixation were evaluated in the different models. RESULTS: Under various motion modes，the ROM of M2 and M3 were significantly lower than those of M1. The ROM reduction of M2 relative to M1 was much greater than that of M3 relative to M2. Moreover, the peak von Mises stresses of endplates in M2 were almost the same as those in M3. In terms of the maximum stresses of cages, M2 and M3 were essentially identical. Besides, the maximum stresses of posterior instrumentation in M2 and M3 were similar, which were mainly concentrated at the root of pedicle screws. CONCLUSION: There were no significant differences between M2 and M3 from the biomechanical analysis. In two-level OLIF, posterior four-screw fixation can replace six-screw fixation, which reduces surgical trauma and decreases economic burden of patients, and will be a cost-effective alternative.

Trehalose inhibits ferroptosis via NRF2/HO-1 pathway and promotes functional recovery in mice with spinal cord injury.

Spinal cord injury (SCI) is the main cause of severe damage to the central nervous system and leads to irreversible tissue loss and neurological dysfunction. Ferroptosis is a cell death pattern, newly discovered in recent years. Ferroptosis is an oxidizing cell death induced by small molecules, and is an iron-dependent process caused by the imbalance between the generation and degradation of lipid reactive oxygen species (ROS) in cells. As an antioxidant, trehalose can effectively prevent lipid peroxidation. Studies have reported that trehalose can improve the prognosis of SCI. However, it is unclear whether these benefits are related to ferroptosis. In this study, we demonstrated for the first time that trehalose reduces the degeneration and iron accumulation of neurons by inhibiting the production of ROS and ferroptosis caused by lipid peroxides after SCI, thus promoting the survival of neurons and improving the recovery of motor function. More specifically, we found that trehalose inhibited the expansion of cavities in the nerve tissue of mice with SCI, inhibited neuron loss, and improved functional recovery. In terms of mechanism, our results indicate that the neuroprotective effect of trehalose is due to the activation of the NRF2/HO-1 pathway, which in turn inhibits ferroptosis and ferroptosis-related inflammation. Our findings provide important insights into the previously unknown role of trehalose in SCI, as well as new evidence supporting the hypothesis that suppression of ferroptosis plays a key neuroprotective role in SCI.

A Novel Rat Tail Needle Minimally Invasive Puncture Model Using Three-Dimensional Printing for Disk Degeneration and Progressive Osteogenesis Research.

Many studies focused on the annulus fibrosus (AF) injury in rodent tail model for the intervertebral disk degeneration (IDD) research. However, previous studies caused tremendous injury of intervertebral disk (IVD) by penetrating whole disk. This study aimed to build a progressive IDD rodent tail model by a novel device for precise and minimally invasive puncture in AF. A precise puncture device was customized by 3D Printing Technique. 40 rodent tail IVDs were randomly grouped as follows: group A, non-puncture; group B, annulus needle puncture (ANP) for 4 week; group C, ANP for 8 week; and group D, ANP for 12 week. Pre- and post-puncture IVD height on radiographs and IVD signal intensity on T2 magnetic resonance imaging (MRI) were measured. Average bone density (ABD) on the end of coccygeal vertebrae between punctured disk was measured on the radiographs. Hematoxylin and eosin, TUNEL staining methods, immunofluorescence for cleaved-caspas3 and immunohistochemistry for aggrecan and collagen II were performed. Progressively and significantly increasing IVD height loss and degenerative grade were observed following the time points. The ABD was respectively, 81.20 ± 4.63 in group A, 83.93±3.18 in group B, 92.65 ± 4.32 in group C, 98.87 ± 6.69 in group D. In both group C and group D, there were significant differences with group A. In histology, increasing number of AF cells was noted in group B. In both group C and D, the fissures in AF were obviously observed, and a marked reduction of AF cells were also observed. In all ANP groups, there were significant decrease in number of NP cells, as well as aggrecan and collagen II contents. TUNEL assay showed cellular apoptosis were stimulated in all puncture group, especially in group D. A progressive IDD rat model could be standardly established by the micro-injury IVD puncture using a novel 3D printing device. This animal model provided a potential application for research of progressive hyperosteogeny following IDD development.

Computed tomography comparison study of two Axis-based C1 transpedicular screw trajectory designs.

BACKGROUND CONTEXT: To our knowledge, there is no comparison study of two different Axis-based C1 transpedicular screw trajectory (TST) designs. PURPOSE: To compare two different Axis-based C1 TST designs. STUDY DESIGN: The computed tomography (CT) morphologic analysis of the two different C1 Axis-based TST designs. METHODS: Firstly, the design of Axis C/M and related measurements were made on a work station by using neck computed tomography angiography (CTA) data of 62 patients. The central axes (Axis M and Axis C) of C1 TST were designed by multiplanar reconstruction (MPR) technique. Based on Axis M and Axis C, the following parameters were measured: (A, A'), distance between the insertion point (IP) and the midline. (B, B'), distance between IP and the inferior aspect of C1 posterior arch. (C, C'), distance between IP and the C1 anterior cortex of the lateral mass along Axis M/C. (D, D'), insertion angle (IA) based on Axis M/C. (E, E'), the narrowest width of the inner medullary cavity (IMC) along Axis M/C. RESULT: The C1 TST can be designed by MPR technique based on CT volume scan. The design of Axis C trajectory was easier to Axis M trajectory. A, A' were 20.7±1.6mm and 20.6±1.9mm. Both B, B' were 2.0±0.6mm. C, C' were 27.2±2.1mm and 27.5±2.1mm. D, D' were 9.9±5.0°and 10.4±7.7°. E, E' were 5.0±1.3mm and 5.4±1.4mm. Among 62 patients (124 sides), Axis C can be achieved by medial inclination, perpendicular, lateral inclination method in 81.5%, 13.7%, 4.8% sides, respectively; Axis M can be achieved by medial inclination, perpendicular, lateral inclination method in 90.3%, 8.9%, 0.8% sides, respectively. CONCLUSION: Axis C can be a reliable trajectory for C1 transpedicular screw insertion as long as there is no displaced fracture in the C1 pedicle and lateral mass. Because of the individual differences, the ideal C1 TST can be achieved by medial inclination, perpendicular or even lateral inclination method, although its inclination direction is medial in the majority of patients.

Lycium barbarum polysaccharide (LBP) inhibits palmitic acid (PA)-induced MC3T3-E1 cell apoptosis by regulating miR-200b-3p/Chrdl1/PPARγ.

BACKGROUND: Obesity is closely related to osteoporosis. Lycium barbarum polysaccharides (LBPs) have anti-osteoporosis activity. OBJECTIVE: This study aimed to explore the role of LBPs in palmitic acid (PA)-induced osteoblast apoptosis. METHODS: The microarray data set GSE37676 was downloaded from Gene Expression Ominibus (GEO) database. Top 300 differentially expressed genes (DEGs) were used to construct a protein-protein interaction (PPI) network based on STRING database, and significant modules were analyzed and their key genes were screened by using Cytoscape software. COEXPEDIA database showed that there was co-expression between Chrdl1 and peroxisome proliferator-activated receptor (PPARγ). MC3T3-E1 cells were treated with 100-500 µg/mL of PA. Reverse transcription polymerase chain reaction (RT-PCR) and western blot assays were used to detect mRNA and protein levels. Cell Counting Kit-8 (CCK-8) assay and flow cytometry were used to detect cell viability and cell apoptosis. RESULTS: Chrdl1 was the key gene from the most significant module and downregulation in MC3T3-E1 cells treated with PA. MicroRNA miR-200b-3p and PPARγ were significantly upregulated among PA-treated MC3T3-E1 cells. The results of luciferase reporter gene assay showed that miR-200b-3p targeted Chrdl1 3'-UTR. Over-expressing miR-200b-3p promoted PA-induced cell apoptosis and inhibited cell viability. After pre-treating cells with PA and LBP, MC3T3-E1 cell apoptosis rate was relatively lower than that of mimics+PA200 group. Chrdl1 inhibition partly reversed miR-200b-3p effect on inhibiting apoptosis among MC3T3-E1 cells pre-treated with LBP and PA. Decreased C CASP3, PPARγ and increased Chrdl1 by miR-200b-3p inhibition were partly reversed by Chrdl1 inhibition. CONCLUSIONS: LBPs inhibit PA-induced MC3T3-E1 cell apoptosis by mainly decreasing miR-200b-3p to upregulate Chrdl1, but miR-200b-3p/Chrdl1/PPARγ is not the only mechanism for LBPs protecting osteoblasts from PA.

The computed tomography angiography study of the spatial relationship between C1 transpedicular screw trajectory and V3 segment of vertebral artery.

BACKGROUND CONTEXT: To our knowledge, there is no study that has systematically analyzed the relationship between C1 transpedicular screw trajectory and V3 segment of vertebral artery (VA V3 segment). PURPOSE: To study the relationship between C1 transpedicular screw trajectory and VA V3 segment. STUDY DESIGN: A morphologic computed tomography angiography (CTA) analysis of the spatial relationship between C1 transpedicular screw trajectory and VA V3 segment. METHODS: Measurements were made on a workstation by using CTA data of 62 patients. Firstly, parameters related to the relationship between C1 vertebral artery groove (VAG) and vertebral artery (VA) were measured: (A) the shortest distance between the posterosuperior aspect of C1 posterior arch and VA; (B) distance between the outer aspect of VAG and VA; (C) distance between midpoint of VAG and VA; and (D) distance between the inner aspect of the VAG and VA. Then, the central axis of trajectory perpendicular to the coronal plane (axis P) and the central axis of trajectory with a medial inclination (axis M) were designed for the basis of measurements. Parameters related to the relationship between axis P/M and VA V3 segment were measured respectively: (E, E'), distance between insertion point and anterior aspect of VA along axis P/M; (F, F'), the shortest distance between axis P/M and the outer cortex of C1 transverse foramen; and (G, G'), the narrowest width of C1 internal medullary canal along axis P/M. RESULT: A, B, C, and D were 1.7±1.0 mm, 1.6±0.9 mm, 1.5±0.7 mm, 2.3±1.1 mm, respectively. E, E' were 5.5±1.7 mm and 4.1±2.3 mm. F, F' were 1.9±0.7 mm and 2.9±0.7 mm. G, G' were 3.7±1.4 mm and 4.8±1.2 mm. There was a little interspace between atlas VAG and VA, which was mainly filled with venous plexus. CONCLUSIONS: There is a close relationship between C1 transpedicular screw trajectory and VA V3 segment. Trajectory with medial inclination technique is suggested especially for female patients.