Biomechanical effect of vertebroplasty on the adjacent intervertebral levels using a three-dimensional finite element analysis / 中华创伤杂志(英文版)

<p><b>OBJECTIVE</b>To investigate the biomechanical effect of different volume, distribution and leakage to adjacent disc of bone cement on the adjacent vertebral body by three-dimensional osteoporosis finite element model of lumbar.</p><p><b>METHODS</b>L(4)-L(5) motion segment data of the cadaver of an old man who had no abnormal findings on roentgenograms were obtained from computed tomography (CT) scans. Three-dimensional model of L(4)-L(5) was established with Mimics software, and finite element model of L(4)-L(5) functional spinal unit (FSU) was established by Ansys 7.0 software. The effect of different loading conditions and distribution of bone cement after vertebroplasty on the adjacent vertebral body was investigated.</p><p><b>RESULTS</b>This study presented a validated finite element model of L(4)-L(5) FSU with a simulated vertebroplasty augmentation to predict stresses and strains of adjacent untreated vertebral bodies. The findings from this FSU study suggested the endplate and disc stress of the adjacent vertebral body was not influenced by filling volume of bone cement but unipedicle injection and leakage to the disc of bone cement could concentrate the stress of adjacent endplate.</p><p><b>CONCLUSIONS</b>Asymmetric distributions and leakage of cement into intervertebral disc can improve the stress of endplate in adjacent vertebral body. These results suggest that optimal biomechanical configuration should have symmetric placement and avoid leakage of cement in operation.</p>

Studies on the hepatic three-dimensional reconstruction and virtual surgery using the hepatic images of the digitized virtual Chinese human female number 1 database / 中华外科杂志

<p><b>OBJECTIVE</b>To study digitized virtual hepatic three-dimensional reconstruction and virtual hepatic surgery.</p><p><b>METHODS</b>The whole series of hepatic images taken from the database of digitized Virtual Chinese Human Female Number 1 (VCH-F1) was employed to reconstruct a three-dimensional (3D) liver. First, studied some algorithms for registration of human liver tissue images, and then, segmented the regions of liver, vein, bile duct, and gallbladder from the images. Based on them, the 3D visualization human liver model was reconstructed. Finally, a 3D visualization demo system of liver was developed based on personal computer and Windows operation system.</p><p><b>RESULTS</b>This demo system of liver provided a graphics user interface to rotate, scale the 3D liver to observe the 3D hepatic structure, and a virtual liver simulation system of resection with primary function.</p><p><b>CONCLUSIONS</b>The study may be beneficial to the future research on digitized virtual hepatic and virtual hepatic surgery, and the 3D visualization demo system of liver may be beneficial to the research on the hepatic structure.</p>