Free iliac crest grafting technology for the management of critical-sized tibial bone defect.

OBJECTIVE: To introduce the method and experience of treating critical-sized tibial bone defect by taking large iliac crest bone graft. METHODS: From January 2020 to January 2022, iliac crest bone grafting was performed in 20 patients (10 men and 10 women) with critical-sized tibial bone defect. The mean length of bone defect was 13.59 ± 3.41. Bilateral iliac crest grafts were harvested, including the inner and outer plates of the iliac crest and iliac spine. The cortical bone screw was used to integrate two iliac bone blocks into one complex. Locking plate was used to fix the graft-host complex, supplemented with reconstruction plate to increase stability when necessary. Bone healing was evaluated by cortical bone fusion on radiographs at follow-up, iliac pain was assessed by VAS score, and lower limb function was assessed by ODI score. Complications were also taken into consideration. RESULTS: The average follow-up time was 27.4 ± 5.6 (Range 24-33 months), the mean VAS score was 8.8 ± 1.9, the mean ODI score was 11.1 ± 1.8, and the number of cortical bone fusion in the bone graft area was 3.5 ± 0.5. Satisfactory fusion was obtained in all cases of iliac bone transplant-host site. No nonunion, shift or fracture was found in all cases. No infection and bone resorption were observed that need secondary surgery. One patient had dorsiflexion weakness of the great toe. Hypoesthesia of the dorsal foot was observed in 2 patients. Ankle stiffness and edema occurred in 3 patients. Complications were significantly improved by physical therapy and rehabilitation training. CONCLUSION: For the cases of critical-sized tibial bone defect, the treatment methods are various. In this paper, we have obtained satisfactory results by using large iliac bone graft to treat bone defect. This approach can not only restore the integrity of the tibia, but also obtain good stability with internal fixation, and operation skills are more acceptable for surgeons. Therefore, it provides an alternative surgical method for clinicians.

The Relationship between Structure and Performance of Different Polyimides Based on Molecular Simulations.

A polyimide (PI) molecular model was successfully constructed to compare the performance of PIs with different structures. In detail, the structure of the cross-linked PI resin, the prepolymer melt viscosity, and the glass-transition temperature (Tg) were investigated using molecular simulations. The results indicate that benzene ring and polyene-type cross-linked structures dominate the properties of the PIs. Moreover, the prepolymer melt viscosity simulations show that the 6FDA-APB and the ODPA-APB systems have a low viscosity. The results for the Tg and the distribution dihedral angle reveal that the key factor affecting bond flexibility may be the formation of a new dihedral angle after cross-linking, which affects the Tg. The above results provide an important reference for the design of PIs and have important value from the perspective of improving the efficiency of new product development.

Preparation and Properties of Modified Phenylethynyl Terminated Polyimide with Neodymium Oxide.

Modified phenylethynyl terminated polyimides (PIs) were successfully prepared by using neodymium oxide (Nd2O3) via high-speed stirring and ultrasonic dispersion methods. In addition, the structure and properties of the Nd2O3-modified imide oligomers as well as the thermo-oxidative stability of the modified polyimides (PI/Nd2O3 hybrid) and its modification mechanism were investigated in detail. The thermogravimetric analysis (TGA) results indicated that the 5% decomposition temperature (Td5%) of the PI/Nd2O3 hybrids improved from 557 °C to 575 °C, which was also verified by the TGA-IR tests. Meanwhile, the weight loss rate of the PI/Nd2O3 hybrids significantly decreased by 28% to 31% compared to that of pure PI under isothermal aging at 350 °C for 450 h when the added content of Nd2O3 was between 0.4 wt% and 1 wt%, showing outstanding thermo-oxidative stability. Moreover, the mechanism of the enhanced thermo-oxidative stability for the modified PIs was analyzed by scanning electron microscopy (SEM) and X-ray diffraction (XRD).

Comparison of Anterior and Posterior Decompressions in Treatment of Traumatic Thoracolumbar Spinal Fractures Complicated with Spinal Cord Injury.

BACKGROUND For patients with thoracolumbar spinal fractures complicated with spinal cord injury, timely surgery is the first choice. We compared the effects of anterior and posterior decompressions in treatment of these patients. MATERIAL AND METHODS A total of 80 male patients with traumatic thoracolumbar spinal fractures and spinal cord injury were prospectively selected and divided into 2 groups. The control group underwent posterior decompression and internal fixation and the observation group underwent real-time anterior decompression. RESULTS The observation group had longer operative time and length of postoperative hospital stay, larger intraoperative blood loss, remarkably greater immediate postoperative anterior height and middle column height of the fractured vertebrae, and a notably smaller Cobb's angle than in the control group. The total ASIA score was significantly higher in the observation group than in the control group immediately after surgery and at 6 months and 1 year after surgery. The maximal urine flow, maximal detrusor pressure, and bladder compliance were also evidently higher in the observation group than in the control group during 1 year of follow-up. Compared with the control group, the International Index of Erectile Function-5 (IIEF-5) score in the observation group was significantly higher at 3 months, 6 months, and 1 year after surgery. CONCLUSIONS Compared with the posterior approach, anterior decompression in patients with thoracolumbar spinal fractures complicated with spinal cord injury can effectually enhance the surgical efficiency, and restore the physiological anatomy of the fractured vertebrae, thereby improving patient quality of life.

LINC00266-1/miR-548c-3p/SMAD2 feedback loop stimulates the development of osteosarcoma.

Osteosarcoma (OS) is one of the most common primary bone malignancies and accounts for 3.4% of pediatric tumors. Its 5-year survival is as low as about 20%. Differentially expressed lncRNAs in OS profiling were searched in the downloaded profile of GSE12865. As a result, LINC00266-1 was detected to be upregulated in both GSE12865 and OS tissues we collected. SMAD2 was the downstream target binding to promoter sites of LINC00266-1, displaying a positive regulatory interaction. Knockdown of LINC00266-1 suppressed the proliferative and metastatic abilities, and promoted the apoptosis in OS cells. Besides, knockdown of LINC00266-1 significantly alleviated the growth of OS in vivo. MiR-548c-3p was the sponge miRNA of LINC00266-1, which was able to reverse the regulatory effects of LINC00266-1 on OS cell phenotypes. Moreover, miR-548c-3p bound to the 3'-UTR of SMAD2 and thus downregulated SMAD2. Overexpression of SMAD2 partially reversed the regulatory effects of LINC00266-1 on OS cell phenotypes. Finally, we have identified that LINC00266-1/miR-548c-3p/SMAD2 feedback loop was responsible for stimulating the development of OS.

CircRNA LRP6 promotes the development of osteosarcoma via negatively regulating KLF2 and APC levels.

We aimed to investigate the biological functions of circLRP6 in the progression of osteosarcoma. CircLRP6 level in OS was detected by quantitative real-time polymerase chain reaction. Correlation between circLRP6 level with survival of OS patients was evaluated. Cell counting kit-8 and Transwell assay were conducted to detect proliferative, migratory and invasive capacities of OS cells. Cell cycle and apoptosis in OS cells influenced by circLRP6 were evaluated by flow cytometry. RNA immunoprecipitation was conducted to verify the binding relationship between circLRP6 with LSD1 and EZH2. Finally, the interaction between LSD1, EZH2 and promoter regions of KLF2, APC was clarified by chromatin immunoprecipitation. CircLRP6 level markedly increased in OS tissues. Besides, OS patients with high expression of circLRP6 showed shorter disease-free survival and over-all survival than those with low expression. CircLRP6 knockdown suppressed proliferative, migratory and invasive rates of OS cells. Moreover, circLRP6 knockdown induced apoptosis and arrested cell cycle in G0/G1 phase. The interaction between circLRP6 with LSD1 and EZH2 mediates their binding to the promoter regions of KLF2 and APC. Knockdown of circLRP6 weakened the binding abilities of LSD1, EZH2 to KLF2, APC. APC overexpression inhibited proliferation, induced apoptosis and arrested cell cycle. Moreover, the tumor-suppressor effect of downregulated circLRP6 on OS could be reversed by APC knockdown. Collectively, circLRP6 was highly expressed in OS and served as an oncogene by binding to LSD1 and EZH2 to inhibit expressions of KLF2 and APC.

LncRNA SNHG3/miRNA-151a-3p/RAB22A axis regulates invasion and migration of osteosarcoma.

To elucidate the potential function of lncRNA SNHG3 in the development of osteosarcoma. Quantitative real-time polymerase chain reaction was conducted for detection of SNHG3, miRNA-151a-3p and RAB22 A in osteosarcoma tissues and cells. Receiver operating characteristic curve was introduced to analyze the diagnostic potential of SNHG3 in osteosarcoma. Correlation between SNHG3 expression and the overall survival of osteosarcoma patients was evaluated using Kaplan-Meier method. Invasive and migratory potentials of osteosarcoma cells were examined by Transwell assay. Furthermore, dual-luciferase reporter gene assay, RNA-pull down and RIP assay were used to verify the binding of SNHG3/RAB22 A to miRNA-151a-3p. The function of SNHG3/miRNA-151a-3p/RAB22 A axis in osteosarcoma was finally confirmed by rescue experiments. SNHG3 and RAB22 A were highly expressed in osteosarcoma patients, while miRNA-151a-3p was lowly expressed. The overall survival of osteosarcoma patients with high expression of SNHG3 was shorter than those with low expression. SNHG3 overexpression markedly promoted invasive and migratory potentials of osteosarcoma cells. Through dual-luciferase reporter gene assay, both SNHG3 and RAB22 A could bind to miRNA-151a-3p. RAB22 A expression was positively regulated by SNHG3, but negatively regulated by miRNA-151a-3p. Finally, rescue experiments confirmed that RAB22 A overexpression could reverse the promotive effects of miRNA-151a-3p knockdown on invasive and migratory potentials of osteosarcoma cells. SNHG3 is highly expressed in osteosarcoma, and promotes the invasive and migratory potentials of osteosarcoma cells by absorbing miRNA-151a-3p to upregulate RAB22 A expression.

Application of a buprenorphine transdermal patch for the perioperative analgesia in patients who underwent simple lumbar discectomy.

This study aimed to investigate the perioperative analgesic effect of a buprenorphine transdermal patch in patients who underwent simple lumbar discectomy.In total, 96 patients were randomly divided into parecoxib intravenous injection (Group A), oral celecoxib (Group B), and buprenorphine transdermal patch groups (Group C). The pain status, degree of satisfaction, adverse effects, and condition in which the patient received tramadol hydrochloride for uncontrolled pain were recorded on the night before surgery, postoperative day 1, postoperative day 3, and postoperative day 5.The degree of patient satisfaction in Group C was higher than that in Groups A and B, with minimal adverse effects.The buprenorphine transdermal patch had a better perioperative analgesic effect in patients who underwent simple lumbar discectomy.