Three months after implantation, micro-computed tomography analysis revealed a 36.4% higher circumferential contact index between PMMA-MC and bone, as compared to PMMA alone. Then, PCD surgery in a goat model with induced disc degeneration was performed with implantation of PMMA-MC or PMMA.

Hydrophilicity of PMMA-MC was greatly improved and its elastic modulus was tailored to complement mechanical performance of bone under dynamic stress. The introduction of MC did not change the application and setting time of PMMA and was easy to be handled in minimally invasive operation. Injectability, hydrophilicity and mechanical properties of the MC-modified PMMA (PMMA-MC) was characterized.

Here, we investigated whether the osteogenic mineralized collagen (MC) modified polymethylmethacrylate (PMMA) cement could be a suitable material in PCD surgery. The CDRX results in a recrystallized structure with significantly reduced defect density in the white layer formed during the turning of Inconel 718.As a minimally invasive surgery, percutaneous cement discoplasty (PCD) is now contemplated to treat lumbar disc degeneration disease in elder population. Furthermore, the grains were refined to submicron, and continuous dynamic recrystallization (CDRX) occurs in the white layer. The lattice mismatch between γ and γ' phases decreases and the white layer is more homogeneous than the original material. Meanwhile, the amount of γ′ phase decreases, and δ phase is crushed and refined within the white layer. The results indicate that the thickness of the white layer is uneven and varies within three microns. After that, the morphology and microstructure of the white layer are studied with the aid of scanning electron microscope (SEM), energy dispersive spectrometer (EDS), X-ray diffraction (XRD), and electron backscatter diffraction (EBSD). Therefore, the dry orthogonal cutting tests with worn tools were conducted to make the white layer first. The core issues, which this paper aims to reveal, are the transition of γ, γ′, γ' and δ phases and dynamic recrystallization mechanism within the white layer formed during turning Inconel 718. Nevertheless, the microstructure of the white layer is still not revealed clearly. White layer is commonly formed on the machined surface of nickel-based Inconel 718 superalloy, which probably induces the generation of cracks, leading to the fatigue life reduction of the workpieces.

Mdi jade 6.5 download