Finite element modeling of material property assignment based on CT gray value and its application in simulation of osteotomy for deformities / 南方医科大学学报

<p><b>OBJECTIVE</b>To explore a new method for finite element modeling to achieve material property assignment based on in situ CT gray value in simulated osteotomies for deformities.</p><p><b>METHODS</b>A CT scan dataset of the lower limb of a patient with extorsion deformity was obtained for three-dimensional reconstruction using Mimics software and preparing a solid model. In the CAD software, the parameters for osteotomy simulation were defined including the navigation axis, rotation angle and reference plane. The tibia model was imported to the FEA pre-processing software for meshing procedure and then exported to Mimics. All the segments of the tibia meshed model were assigned uneven material properties based on the relationship between CT gray values and material properties in the Mimics software. Finally, all the segments of the tibia model, reference axis and reference plane were assembled in the pre-processing software to form a full finite element model of a corrected tibia, which was submitted to resolver for biomechanical analysis.</p><p><b>RESULTS</b>The tibia model established using our modeling method had inhomogeneous material properties based on CT gray values, and was available for finite element analysis for the simulation of osteotomy.</p><p><b>CONCLUSIONS</b>The proposed finite element modeling method, which retains the accuracy of the material property assignment based on CT gray value, can solve the reposition problem commonly seen in modeling via the routine method of property assignment and provides an efficient, flexible and accurate computational biomechanical analysis method for orthopedic surgery.</p>

Clinical analysis of childhood Henoch-Schonlein purpura on the Tibetan Plateau, China / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To study the clinical characteristics of childhood Henoch-Schonlein purpura (HSP) on the Tibetan Plateau, China.</p><p><b>METHODS</b>One hundred and twenty-five HSP children admitted to Shannan People's Hospital, Tibet, were assigned to the observation group, and 96 HSP children admitted to Wuhan Children's Hospital were assigned to the control group. The disease characteristics, clinical manifestations, treatment, and prognosis in both groups were retrospectively analyzed and compared.</p><p><b>RESULTS</b>The mean age of HSP onset and the female-to-male ratio in the observation group were both significantly higher than in the control group (P<0.05). There was a significant difference in seasonal onset between two groups. Significant differences in the etiological factors were observed between the two groups (P<0.05). The gastrointestinal manifestation was more prominent in the observation group compared with that in the control group (P<0.05). Laboratory findings showed that the mean erythrocyte sedimentation rate, counts of white blood cells and platelets, and percentage of neutrophil leucocytes were significantly lower, while the hemoglobin level was significantly higher in the observation group than in the control group (P<0.05). A total of 124 HSP patients (99.2%) in the observation group had a full recovery or improvement, and the overall cure rate and improvement rate showed no significant differences between two groups (P>0.05). Only 2.4% of the patients (3 cases) in the observation group had recurrent attack during follow-up, which was significantly lower than that in the control group (16.7%; P<0.05).</p><p><b>CONCLUSIONS</b>Childhood HSP on the Tibetan Plateau shows partial differences in disease characteristics, clinical manifestations, and laboratory measurements compared with that in the plain area. The overall prognosis is better and the recurrent rate is lower among HSP children on the Tibetan Plateau.</p>

Clinical observation of cholestatic liver disease caused by cytomegalovirus infection treated by lidan mixture: a case report of 120 infants / 中国中西医结合杂志

<p><b>OBJECTIVE</b>To observe the clinical effects of Linda Mixture (LM) on cholestatic liver diseases caused by cytomegalovirus (CMV) infection.</p><p><b>METHODS</b>Totally 240 CMV infected cholestatic liver diseases infants, who were hospitalized at the Department of Integrated Traditional Chinese and Western Medicine, Wuhan Children's Hospital from January 2008 to June 2011, were randomly assigned to the treatment group (120 cases) and the control group (120 cases). Patients in the treatment group were treated by LM combined ganciclovir, while those in the control group were treated by ganciclovir alone. The therapeutic course was 2 months. The patients were assigned to 3 sub-groups according to the quantification standards of symptoms and signs, i. e., the No. 1 treatment group (mild, 30 cases), the No. 1 control group (mild, 30 cases), the No. 2 treatment group (moderate, 30 cases), the No. 2 control group (moderate, 30 cases), the No. 3 treatment group (severe, 30 cases), the No. 1 control group (severe, 30 cases). The clinically cured rate and the total effective rate, the jaundice subside time, the retraction time for Gan and Pi, the body weight growth, the indices of the liver function, and lab indices of CMV infection were observed before and after treatment.</p><p><b>RESULTS</b>After treatment the cured rate was 77.50% and the total effective rate was 88.33% in the treatment group, while they were 60.83% and 76.67% in the control group. There was statistical difference between the two group (P<0.05, P<0.01). There was some improvement in the jaundice subside time, the retraction time for Gan and Pi, the body weight growth, the indices of the liver function in the two groups. Better results were obtained in the treatment group than in the control group, showing statistical difference (P<0.05, P<0.01). The lab indices of CMV infection showed negative to some degrees. The negative rates of serum IgM (83.54% in the treatment group and 63. 64% in the control group) and the serum CMVDNA (84.52% in the treatment group and 67.47% in the control group) were better in the treatment group than in the control group, showing statistical difference (P<0.01). There was no obvious difference in the negative rate of CMV antigen in urine between the two groups (P>0.05).</p><p><b>CONCLUSIONS</b>LM combined ganciclovir therapy showed definite effects in treating cholestatic liver diseases caused by CMV infection. Early treatment for severe infants might change their prognosis. LM also could alleviate adverse reactions during the therapeutic course.</p>