Research on geometric feature of femoral medullary cavity and it's matching with intramedullary nail / 中华骨科杂志

Objective To investigate the geometric feature of femoral medullary cavity through CT scanning and it's matching with femoral intramedullary nail,and to analysis the reason for difficulties in implanting distal lock pin.Methods Thirty dried femur specimens were measured through CT scanning,and twenty images were taken evenly according to the total length of shaft of femur from each femur.In each image,the data of the central axis point and eight points around medullary cavity wall in X and Y axes were obtained,which were used to reconstruct the three-dimensional models of medullary cavity,central axis,intramedullary nail by computer software.And the models were overlapped for comparison.Then the coronal and sagittal fold line charts for central axis of medullary cavity were drawn.The inserting process of intramedullary nail was simulated to observe whether the nail would punch out of the medullary cavity wall.Results The central axis of femoral medullary cavity and intramedullary nail were overlapped and compared.They matched well in the coronal plane,but the curves of femoral medullary cavity were larger than those of intramedullary nails in sagittal plane.While simulating the inserting process of intramedullary nail,6 nails punched out of the medullary cavity wall in coronal plane (20％,6/30),so did 13 nails in sagittal plane (43％,13/30).Conclusion Intramedullary nails match well with most of the femoral medullary cavities.However,the anatomic structure of the femoral medullary cavity differs individually.Curves of some femoral medullary cavity are large,which can cause deformation of intramedullary nail,and this is the main reason for the failure of distal locking.

Biological evaluation of the effect of a protective cover against inhalation of depleted uranium dust particles / 第三军医大学学报

Objective To evaluate the biological effect of a kind of protective cover against inhalation of depleted uranium (DU) dust particles. Methods At 1 and 3 d after inhalation of DU dust particles, uranium concentrations in the blood, lung, bronchia, kidney, and liver of the rats in the protected group and non protected group were measured and the efficiency of protection was calculated. Results Uranium levels in all tissues and fluids of the rats in the protected group decreased significantly to 71.2%-96.1% as compared with those in non protected group. Conclusion The protective cover is effective to reduce the harm due to inhalation of DU dust particles.