Steroid-induced avascular necrosis of the femoral head (SANFH) is a common orthopaedic disease that is difficult to treat. The present study investigated the effects of total flavonoids of Rhizoma drynariae (TFRD) on SANFH and explored its underlying mechanisms. The SANFH rat model was induced by intramuscular injection of lipopolysaccharides and methylprednisolone. Osteoblasts were isolated from the calvariae of neonatal rats and then cultured with dexamethasone (Dex). TFRD was used in vitro and in vivo, respectively. Haematoxylin and eosin staining was used to assess the pathological changes in the femoral head. Terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end labelling assay and flow cytometry were conducted to detect apoptosis of osteoblasts. The 2' ,7'-dichlorofluorescein-diacetate staining method was used to detect reactive oxygen species (ROS) levels in osteoblasts and the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay was used to detect osteoblast proliferation. The expression of caspase-3, Bax, Bcl-2, VEGF, runt-related transcription factor 2 (RUNX2), osteoprotegerin (OPG), osteocalcin (OCN), receptor activator of nuclear factor κB ligand (RANKL) and phosphoinositide 3-kinase (PI3K)/AKT pathway related-proteins were detected via western blotting. It was found that TFRD reduced the pathological changes, inhibited apoptosis, increased the expression of VEGF, RUNX2, OPG and OCN, decreased RANKL expression and activated the PI3K/AKT pathway in SANFH rats. TFRD promoted proliferation, inhibited apoptosis and reduced ROS levels by activating the PI3K/AKT pathway in osteoblasts. In conclusion, TFRD protected against SANFH in a rat model. In addition, TFRD protected osteoblasts from Dex-induced damage through the PI3K/AKT pathway. The findings of the present study may contribute to find an effective treatment for the management of SANFH.

Background Inversion deformities caused by insufficient medial support are especially common when the PHILOS locking plate is used to treat proximal humeral fractures. Using finite element analysis, we aimed to compare the biomechanical properties of a PHILOS locking plate (PLP) and a PLP combined with a lateral intertubercular sulcus plate (PLP-LSP) in the fixation of proximal humeral fractures with loss of the medial column. Methods After creating a three-dimensional finite element model of a proximal humeral fracture with loss of the medial column, three implant models were established. A full-screw PLP was used in Group A, a PHILOS plate lacking medial screw support and an additional steel plate (MPLP-LSP) were used in Group B, and a full-screw PLP-LSP was used in Group C. The three fixation models were applied to the proximal humeral fracture model, following which horizontal, compressive, and rotational loads were applied to the humerus model. We evaluated structural stiffness and stress distribution in the implant and compared displacement and angle changes among the three models. Results Displacement and angle changes were smallest in Group C (PLP-LSP). The implant model used in Group C also exhibited greater structural rigidity, endured less von Mises stress, and was more stable than the models used in Group A and Group B. Conclusion An LSP placed at the intertubercular sulcus provides effective lateral and medial support, thereby reducing stress on the PLP and providing better stability with proximal humeral fractures.

In order to ensure the safety in using a large cylindrical storage tank, it is necessary to regularly detect its deformation. The traditional total station method has high accuracy in determining the deformation, however, it has a low measurement efficiency. Long-term observation means, there are more risks in the petrochemical plant, therefore, this paper proposes the usage of the 3D laser scanner, replacing the traditional total station to determine the deformation of a large cylindrical storage tank. The Matlab program, is compiled to calculate the point cloud data, while the tank deformation is analyzed from two different points which are, the local concave convex degree and the ovality degree. It is concluded that, the difference between the data obtained by 3D laser scanning, and total station is within the range of oil tank deformation limit, therefore, 3D laser scanner can be used for oil tank deformation detection.