Comparison the treatment of anterior inferior tibiofibular ligament anatomical repair and syndesmosis screw fixation for syndesmotic injuries in ankle fracture.

BACKGROUND: The fixation method of syndesmotic injuries in ankle fractures remains controversial. The goal of the study was to compare radiographic and clinical outcomes between anterior inferior tibiofibular ligament (AITFL) anatomical repair with syndesmosis screw fixation in syndesmotic injuries. METHODS: We analyzed 62 patients who were treated with AITFL anatomical repair or syndesmosis screw fixation for syndesmotic injuries in an advanced teaching hospital between March 2016 and March 2019. Fixation was performed with AITFL anatomical repair in 30 patients (AAR group) and syndesmosis screw in 32 patients (SS group). Radiographic evaluations were the differences in mean anterior and posterior (A difference and P difference) tibiofibular distance between injured and uninjured ankle computed tomography (CT) scan at 6 months postoperatively. Clinical evaluation of patients was done using the American Orthopaedic Foot & Ankle Society (AOFAS) Ankle Hindfoot Score, the Olerud-Molander Ankle (OMA) score and visual analogue scale (VAS) score at 1, 3, 6 months and 1, 2 years postoperatively. RESULTS: The A difference and P difference on CT was no differences (1.6 ± 0.8 mm, 1.3 ± 0.7 mm vs. 1.5 ± 0.7 mm, 1.2 ± 0.7 mm) between the two groups (All of P > 0.05). The AAR group had higher mean AOFAS score (65.6 ± 5.9, 82.3 ± 4.2, 87.6 ± 5.6 vs. 61.8 ± 5.2, 79.1 ± 4.0, 83.8 ± 4.9; P = 0.008, 0.003, 0.007) and higher mean OMA score (45.7 ± 8.7, 79.2 ± 6.5, 84.1 ± 5.3 vs. 40.4 ± 7.3, 74.8 ± 6.3, 80.3 ± 5.8; P = 0.012, 0.009, 0.010)) at 1, 3 and 6 months postoperatively. The AAR group had lower mean VAS scores (2.6 ± 1.2, 1.7 ± 0.7 vs. 3.4 ± 1.2, 2.2 ± 1.1; P = 0.018, 0.038) at 1 and 3 months postoperatively. CONCLUSIONS: The results of this study suggest that the AITFL anatomical repair technique could effectively improve ankle function during daily activity. Therefore, AITFL anatomical repair technique is expected to become a better fixation method for syndesmotic injuries.

Neural differentiation of bone marrow mesenchymal stem cells with human brain-derived neurotrophic factor gene-modified in functionalized self-assembling peptide hydrogel in vitro.

OBJECTIVE: To investigate the biocompatibility and differentiation of human brain-derived neurotrophic factor (hBDNF) gene-modified bone marrow mesenchymal stem cells (hBDNF-rMSCs) in a functionalized self-assembling peptide hydrogel. METHODS: hBDNF was engineered in rMSCs using adenovirus vector and the enhanced green fluorescence protein (eGFP) was used as a reporter gene. Mesenchymal stem cell-specific surface markers (CD90, CD29, and CD45) were used for identifying rat-derived MSCs. Fluorescence microscope was used to detect the transfection of rMSCs. hBDNF-rMSCs and control cells (eGFP-rMSCs) were seeded in a functional self-assembling peptide hydrogel (RADA16-PRG hydrogel) and a control hydrogel (RADA16 hydrogel). Cells were divided into three groups (hBDNF-rMSCs + RADA16 hydrogel, hBDNF-rMSCs + RADA16-PRG hydrogel, and eGFP-rMSCs + RADA16-PRG hydrogel) and a control group (eGFP-rMSCs + RADA16 hydrogel). Cell growth, cell proliferation, expression of hBDNF-mRNA, the level of hBDNF, neuron-specific enolase (NSE), and glial fibrillary acidic protein (GFAP) protein were analyzed for each group. RESULTS: rMSCs were positive for CD90 and CD29 and negative for CD45, green fluorescence was strongly visible at 72 hours after transfection. Compared with control group, the expression of hBDNF-mRNA and levels of hBDNF protein in both hBDNF group were significantly increased (P < 0.01), the cell growth, cell proliferation, and levels of NSE and GFAP protein were significantly increased in three groups ( P < 0.01). Cell growth, cell proliferation, expression of hBDNF-mRNA, and levels of hBDNF, NSE, and GFAP protein in hBDNF-rMSCs + RADA16-PRG hydrogel group were significantly higher than that of hBDNF-rMSCs + RADA16 hydrogel group ( P < 0.01). CONCLUSION: Bone marrow MSCs can be induced into neural cells by the human brain-derived neurotrophic factor gene in a RADA16-PRG functionalized self-assembling peptide hydrogel.

Comparative experimental study of the biomechanical properties of retrograde tibial nailing and distal tibia plate in distal tibia fracture.

Objective: A biomechanical comparative analysis was conducted to evaluate the retrograde tibial nailing (RTN) and distal tibia plate techniques for the treatment of distal tibia fractures. Methods: Fourteen fresh adult tibia specimens were selected, consisting of seven males and seven females aged 34-55 years. The specimens were randomly divided into two groups (Group A and Group B) using a numerical table method, with seven specimens in each group. Group A underwent internal fixation of distal tibial fractures using RTN, while Group B received internal fixation using a plate. The axial compression properties of the specimens were tested in the neutral positions under pressures of 100, 200, 300, 400, and 500 N. Additionally, the torsional resistance of the two groups was assessed by subjecting the specimens to torques of 1.0, 2.0, 3.0, 4.0, and 5.0 N m. Results: At pressures of 400 and 500 N, the axial compression displacement in Group A (1.11 ± 0.06, 1.24 ± 0.05) mm was significantly smaller than that in Group B (1.21 ± 0.08, 1.37 ± 0.11) mm (p = 0.023, 0.019). Moreover, at a pressure of 500 N, the axial compression stiffness in Group A (389.24 ± 17.79) N/mm was significantly higher than that of the control group (362.37 ± 14.44) N/mm (p = 0.010). When subjected to torques of 4 and 5 N m, the torsion angle in Group A (2.97° ± 0.23°, 3.41° ± 0.17°) was significantly smaller compared to Group B (3.31° ± 0.28°, 3.76° ± 0.20°) (p = 0.035, 0.004). Furthermore, at a torque of 5 N m, the torsional stiffness in Group A (1.48 ± 0.07) N m/° was significantly higher than that in Group B (1.36 ± 0.06) N·m/° (p = 0.003). Conclusion: The results obtained from the study demonstrate that the biomechanical performance of RTN outperforms that of the distal tibial plate, providing valuable biomechanical data to support the clinical implementation of RTN.

MSN@IL-4 Sustainingly Mediates Macrophagocyte M2 Polarization and Relieves Osteoblast Damage via NF-κB Pathway-Associated Apoptosis.

Background: The microenvironment of bone defects displayed that M2 polarization of macrophagocyte could promote the osteoblast growth and benefit the wound healing. Bone scaffold transplantation is considered to be one of the most promising methods for repairing bone defects. The present research was aimed at constructing a kind of novel bone scaffold nanomaterial of MSN@IL-4 for treating bone defects responding to the wound microenvironment of bone defects and elucidating the mechanics of MSN@IL-4 treating bone defect via controlling release of IL-4, inducing M2 polarization and active factor release of macrophagocyte, and eventually relieving osteoblast injury. Methods: MSN@IL-4 was firstly fabricated and its release of IL-4 was assessed in vitro. Following, the effects of MSN@IL-4 nanocomplex on the release of active factors of macrophage were examined using Elisa assay and promoting M2 polarization of the macrophage by immunofluorescence staining. And then, the effects of active factors from macrophage supernatant induced by MSN@IL-4 on osteoblast growth were examined by CCK-8, flow cytometry, and western blot assay. Results: The release curve of IL-4 in vitro displayed that there was more than 80% release ratio for 30th day with a sustained manner in pH 5.5. Elisa assay data showed that MSN@IL-4 nanocomplex could constantly promote the release of proproliferative cytokine IL-10, SDF-1α, and BMP-2 in macrophagocyte compared to only IL-4 treatment, and immunofluorescent image showed that MSN@IL-4 could promote M2 polarization of macrophagocytes via inducing CD206 expression and suppressing CD86 expression. Osteoblast injury data showed that the supernatant from macrophagocyte treated by MSN@IL-4 could promote the osteoblast proliferation by MTT assay. Flow cytometry data showed that the supernatant from macrophagocyte treated by MSN@IL-4 could suppress the osteoblast apoptosis from 22.1% to 14.6%, and apoptosis-related protein expression data showed that the supernatant from macrophagocyte treated by MSN@IL-4 could suppress the expression of Bax, cleaved caspase 3, and cleaved caspase 8. Furthermore, the immunofluorescent image showed that the supernatant from macrophagocyte treated by MSN@IL-4 could inhibit nucleus location of p65, and western blot data showed that the supernatant from macrophagocyte treated by MSN@IL-4 could suppress the phosphorylation of IKK and induce the expression of IκB. Conclusion: MSN@IL-4 could control the sustaining release of IL-4, and it exerts the protective effect on osteoblast injury via inducing M2 polarization and proproliferative cytokine of macrophagocyte and following inhibiting the apoptosis and NF-κB pathway-associated inflammation of osteoblast.

Synthesis and Characterization of Zirconium Nitride Nanopowders by Internal Gelation and Carbothermic Nitridation.

Zirconium compounds has been widely attention over the last decades due to its excellent physical and chemical properties. Zirconium nitride nanopowders were synthesized via a simple direct carbothermic nitridation process of internal gel derived zirconia in the presence of nano-sized carbon black. The effects of reaction temperature, dwell time and molar ratio of carbon black to Zr (C/Zr) on the phase composition, grain size and crystal parameters of products were studied. Based upon the analysis of crystallite phase evolution and microstructure characterization, it was found that zirconium oxynitride is intermediate product and then O atoms in oxynitride were extracted by oxygen getter, carbon black. Anion sites were directly replaced by N atoms to form rock-salt type nitride in carbothermic nitridation process.