Objective To study the influence of the immersed time by hydrogen dioxide on the characteristics of bovine cancellous bone granules in various periods. Methods Ten 24-month-old Qinchuan bovine, male or female, weighing 150-170 g, were selected. Cancellous bone granules from metaphysic of bovine long bone were cut into cubes of 5 mm × 5 mm ×5 mm and immersed by 8.8 mol/L hydrogen dioxide for 0, 12, 24, 36, 48, 60 and 72 hours separately. Determination of ash, scanning electron microscope, X-ray energy spectrum and micro CT were used to investigate the changes of composition, structure and qual ity of bone. Results With the immersed time increasing, the contents of organics in the bone cancellous were reduced gradually, and obviously decreased during the periods of 0 to 24 hours and 60 to 72 hours (P lt; 0.05). The contents of calcium and phosphorus decreased gradually, they could not be detected almost after 60 days (P lt; 0.05). Bone mineral density and bone mineral content were decreased obviously after 60 hours (P lt; 0.05). The bone trabecula became sl immer and trabecular spacing became larger. Conclusion Hydrogen dioxide can be used to remove the antigen in xenogeneic bone; however as the time increasing (more than 60 hours) the composition and structure will be damaged. Thus it is important to control the immersed time for maintaining the biological characteristics of xenogeneic bone substitute as well as el iminating antigen by hydrogen dioxide.
ObjectiveTo measure L1-L5 lumbar isthmus thickness and to construct Chinese adult male lumbar (L1-L5) 3D model by Micro CT 3D reconstruction technique, in order to provide micro-anatomical data for clinical treatment of L1-L5 lumbar spondylolysis. MethodsDry, non-damaged specimens of L1-L5 lumbar isthmus from 60 Chinese adult males were randomly selected from September 2013 to January 2014. Micro CT scanning was carried out, followed by corresponding 3D model construction. The microscopic anatomical parameters such as superior, inferior, inner and outer edge thickness of left and right L1-L5 lumbar isthmus were measured. ResultsL1-L5 lumbar isthmus superior edge thickness was in the order of L1> L2> L3> L5> L4, with the variation ranging from (4.31±0.95) mm to (4.88±0.75) mm. L1-L5 lumbar isthmus inferior edge thickness was in the order of L1< L2< L3< L4< L5, gradually thickened with the variation ranging from (6.03±1.01) mm to (7.27±1.27) mm. L1-L5 lumbar isthmus inner edge thickness amplitude was not obvious, ranging from (6.33±1.21) mm to (6.57±1.27) mm. L1-L5 lumbar isthmus outer edge thickness was in the order of L1< L2< L3< L4< L5, gradually thickened with the variation ranging from (8.44±1.21) mm to (10.27±1.28) mm. ConclusionThere are certain rules within superior, inferior, inner and outer edge thickness of adult L1-L5 lumbar isthmus:the inferior and outer edge thickness of L1-L5 lumbar isthmus gradually becomes thicker, while superior edge gradually becomes thinner. From L1 to L5 lumbar isthmus, the outer edge of the lumbar isthmus is the thickest, followed by inner and inferior edge, and the upper edge is the thinnest.