DHS fixation has a larger skin incision and more soft tissue dissection, but it is associated with lower rates of fixation failure, reoperation, and overall rate of postoperative complications, and its use in elderly patients with osteoporosis is still recommended due to simplicity, efficacy, and high overall success rate. Multicenter RCTs with large samples are needed to better understand the comparative efficacy and safety of MCS and DHS in femoral neck fractures of restricted fracture type.

In order to improve the biocompatibility of carbon/carbon(C/C) composites used for hip prosthesis, pyrolytic carbon coating was prepared on their surface by chemical vapor deposition. The microstructures of the samples were analyzed by scanning electron microscopy (SEM) and the biomedical response was assessed by the morphology and proliferation of MG63 osteoblast-like cells. The results show that the texture on the surface of C/C composites changes from chaotic structure to uniform state after the pyrolytic carbon coating is prepared. Osteoblasts cultured on pyrolytic carbon coating present flat shape with thin thickness, and display better proliferation in comparison with those on the uncoated C/C composites surface.

Bioactive calcium phosphate coatings were deposited on carbon/carbon（C/C） composites using electrochemical deposition technique. The effects of electrolyte concentration and constant current density on morphology, structure and composition of the coating were systematically investigated using scanning electron microscopy (SEM), X-ray diffraction (XRD) and Fourier transformed infrared (FTIR) spectroscopy. The results show that, the coating weight elevated gradually with the increase of electrolyte concentration, and the morphology of coatings changed from spherical particles to nanolamellar crystals with interlocking structure initially. Then the coating transformed into seaweed-like and nano/micro-sized crystals along the depth direction of the coating. The coatings showed seaweed-like morphology as the deposition current density was less than 20mA. With the less current density, the coating became more homogenous. However, the coating was fiakiness crysal, with needlike crystal stacked upside as the current density reached to 20mA/cm2. The coating weight was improved gradually when the current density increased from 2.5mA/cm2 to 10mA/cm2, then reduced with the increasing current density in the range of 10 to 20mA/cm2.

Surface modification of kaolin, which included coupling agent, calcination, acid modification and alkali activation, mechanochemical activation and intercalation etc, is reviewed. The modification mechanisms and modification methods of kaolinite are discussed. The application of kaolin in ceramics, paints, plastics and rubber etc are also analyzed. Afterwards, the prospect of future researches on modification of kaolin is taken. Surface modification of kaolin denotes use physical, chemical methods and mechanical method, which changes surface properties of kaolinite (surface functional groups, crystal structure and surface adsorption and surface electrical) to satisfy the requirements of the industrial application. Surface properties of kaolinite are controlled by the position of Si-O bonding and Al-(O, OH) groups. Any physical or chemical processing methods which may change Si-O and Al-(O, OH) bonding forms of kaolinite surface could complete the surface modification of kaolin. The surface modification of includes coupling agent, calcination, acid modification and alkali activation, mechanochemical activation, intercalation and so on.

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