Biomechanical analysis of a new cannulated screw for unstable femoral neck fractures.

Background: The treatment of unstable femoral neck fractures (FNFs) remains a challenge. In this study, a new cannulated screw for unstable FNFs was designed to provide a new approach for the clinical treatment of these injuries, and its biomechanical stability was analyzed using finite element analysis and mechanical tests. Methods: An unstable FNF model was established. An internal fixation model with parallel inverted triangular cannulated screws (CSs) and a configuration with two superior cannulated screws and one inferior new cannulated screw (NCS) were used. The biomechanical properties of the two fixation methods were compared and analyzed by using finite element analysis and mechanical tests. Results: The NCS model outperformed the CSs model in terms of strain and stress distribution in computer-simulated reconstruction of the inverted triangular cannulated screw fixation model for unstable FNFs. In the biomechanical test, the NCS group showed significantly smaller average femoral deformation (1.08 ± 0.15 mm vs. 1.50 ± 0.37 mm) and fracture line displacement (1.43 ± 0.30 mm vs. 2.01 ± 0.47 mm). In the NCS group, the mean stiffness was significantly higher than that in the CSs group (729.37 ± 82.20 N/mm vs. 544.83 ± 116.07 N/mm), and the mean compression distance was significantly lower than that in the CSs group (2.87 ± 0.30 mm vs. 4.04 ± 1.09 mm). Conclusion: The NCS combined with two ordinary cannulated screws in an inverted triangle structure to fix unstable FNFs can provide better biomechanical stability than CSs and exhibit a length- and angle-stable construct to prevent significant femoral neck shortening.

Finite element analysis of wedge and biconcave deformity in four different height restoration after augmentation of osteoporotic vertebral compression fractures.

PURPOSE: Biomechanical comparison of wedge and biconcave deformity of different height restoration after augmentation of osteoporotic vertebral compression fractures was analyzed by three-dimensional finite element analysis (FEA). METHODS: Three-dimensional finite element model (FEM) of T11-L2 segment was constructed from CT scan of elderly osteoporosis patient. The von Mises stresses of vertebrae, intervertebral disc, facet joints, displacement, and range of motion (ROM) of wedge and biconcave deformity were compared at four different heights (Genant 0-3 grade) after T12 vertebral augmentation. RESULTS: In wedge deformity, the stress of T12 decreased as the vertebral height in neutral position, flexion, extension, and left axial rotation, whereas increased sharply in bending at Genant 0; L1 and L2 decreased in all positions excluding flexion of L2, and T11 increased in neutral position, flexion, extension, and right axial rotation at Genant 0. No significant changes in biconcave deformity. The stress of T11-T12, T12-L1, and L1-L2 intervertebral disc gradually increased or decreased under other positions in wedge fracture, whereas L1-L2 no significant change in biconcave fracture. The utmost overall facet joint stress is at Genant 3, whereas there is no significant change under the same position in biconcave fracture. The displacement and ROM of the wedge fracture had ups and downs, while a decline in all positions excluding extension in biconcave fracture. CONCLUSIONS: The vertebral restoration height after augmentation to Genant 0 affects the von Mises stress, displacement, and ROM in wedge deformity, which may increase the risk of fracture, whereas restored or not in biconcave deformity.

MicroRNA-628-5p inhibits cell proliferation in glioma by targeting DDX59.

Recent study has reported that microRNA-628-5p (miR-628-5p) is involved in the development of epithelial ovarian cancer; however, the mechanisms of miR-628-5p in glioma remain unclear. In this study, we explored the potential biological roles of miR-628-5p in glioma. First, we found that miR-628-5p was decreased in the tissues and cells (U87 and T98) of glioma. Second, overexpressing miR-628-5p reduced the ability of glioma cells' proliferation and induced glioma cells' cycle arrest in G1. Then, we found that miR-628-5p directly bound to the 3'-untranslated region of DDX59 and decreased the protein level of DDX59. The decrease of DDX59 was found to lead to the decrease of p-AKT. Mechanistic studies revealed that restoring the expression of DDX59 alleviated miR-628-5p-induced inhibition of proliferation of glioma. These findings suggest that the miR-628-5p/DDX59 axis has a key role in the development of glioma, and miR-628-5p might be a new therapeutic target against glioma.

Pouch Roux-en-Y vs No Pouch Roux-en-Y following total gastrectomy: a meta-analysis based on 12 studies.

After a total resection of the stomach, the continuity of the gastrointestinal tract can be restored either by Roux-en-Y esophagojejunostomy with or without a pouch. There is still no consensus on the best reconstruction technique. The aim of this report was to derive a more precise estimation of Roux-en-Y esophagojejunostomy with a pouch compared with Roux-en-Y esophagojejunostomy without a pouch. Studies were identified by PubMed and Embase searches, and the inclusion criteria were randomized controlled trials (RCTs) comparing reconstruction techniques between Roux-en-Y with and without a pouch. A total of 12 studies including 1,018 patients were included. The meta-analysis shows that pouch Roux-en-Y does not significantly increase total postoperative complications, anastomotic leakage or mortality. Importantly, there is no significant difference in 5-year survival rates between the two groups. Patients with Roux-en-Y esophagojejunostomy complained significantly less of reflux symptoms and dumping syndrome, and had significantly less severe reflux esophagitis. Quality of life was significantly improved in patients with Roux-en-Y esophagojejunostomy with a pouch compared with patients who received Roux-en-Y reconstruction without a pouch. The results indicate the need for Roux-en-Y esophagojejunostomy with a pouch is a gastric substitute after total gastrectomy by comparison with Roux-en-Y esophagojejunostomy without a pouch.