Morphometric measurement of the patella on 3D model reconstructed from CT scan images for the southern Chinese population / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Due to racial differences in the morphology of the knee joint and due to most prostheses available in the market being designed using measurements from Caucasians, the objective of this study was to provide the morphometric data of the patella for the southern Chinese population for total knee arthroplasty (TKA), patellar resurfacing, and prostheses design.</p><p><b>METHODS</b>The CT slices of the knee joint were obtained from both knees of 40 Chinese volunteers (20 females, 20 males, and age from 20-25 years) by performing a computer tomographic scan. A 3D model was reconstructed by Mimics software based on the computed tomography images. Six metrical characteristics were measured by digital ruler. Statistical analysis was performed with the SPSS statistical program.</p><p><b>RESULTS</b>The mean, standard deviation and P values of measurements and ratios were calculated using SPSS. All dimensions showed a significant gender difference with P < 0.05, but the six variables of the left and right knees had no statistical significance with P > 0.05. In addition, we studied the relationship between six couples (H-W, H-T, H-HAF, W-T, W-HAF, T-HAF) of the four variables (H: height, W: width, T: thickness and HAF: height of articulating facet) that were measured, which showed a significant correlation.</p><p><b>CONCLUSIONS</b>Examination of the southern Chinese population revealed that males have larger patellae than women. In both genders, comparing data between left and right knees shows no statistically significant difference. Compared with Westerners in previous studies, the patella in our study was thin and small. There was a good linear regression correlation between measurements of the patella. The indirect measurement method on 3D models makes it easy to obtain anatomical data, and the results can provide a region and gender specific database for morphometric measurements of the patella, and can be helpful for designing implants suited for southern Chinese patients.</p>

Effects of remifentanil preconditioning on renal injury induced by limb ischemia-reperfusion in rats / 中华麻醉学杂志

Objective To evaluate the effects of remifentanil preconditioning on the renal injury induced by limb ischemia-reperfusion (I/R) in rats.Methods Twenty-seven healthy male Sprague-Dawley rats,weighing 200-250 g,were randomly assigned into 3 groups (n =9 each):sham operation group (Sham group),I/R group and remifentanil preconditioning group (RPC group).Limb ischemia was induced by clamping bilateral femoral arteries and veins for 2 h,followed by 24 h reperfusion in I/R and RPC groups.Remifentanil 1.0 μg· kg-1 · min-1 was infused via the caudal vein for 30 min before ischemia in RPC group,while the equal volume of normal saline was given in Sham and I/R groups.Blood sample was taken from the inferior vena cava at 24 h of reperfusion to measure blood urea nitrogen (BUN) and creatinine (Cr) concentrations in serum.The rats were sacrificed and the left kidney was removed for determination of tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6) contents,cell apoptosis and microscopic examination of pathological changes.Apoptosis index was calculated.Results Apoptosis index and concentrations of BUN and Cr in serum,TNF-α and IL-6 contents,and apoptosis index were significantly higher,and the pathological changes were more severe in I/R and RPC groups than in Sham group.Compared with group I/R,concentrations of BUN and Cr in serum,TNF-α and IL-6 contents,and apoptosis index were significantly decreased,and the pathological changes were attenuated in RPC group.Conclusion Remifentanil preconditioning can attenuate renal injury induced by limb I/R in rats,and inhibition of inflammatory responses and cell apoptosis in kidney may be involved in the mechanism.

Evaluation of acetabular cup placement precision in Stryker computer-assisted navigated total hip arthroplasty / 中国医疗器械杂志

To contrast the methodology of measuring cup placement precision utilizing Mimics and Matlab programming, based on clinical CT images of primary THA cases with computer assisted navigated surgery (CANS) and with the traditional manual method (MANS). The method was applied and analyzed to measure cup anteversion, cup abduction of 50 clinical cases with CANS and MANSThe results show that, cup placement precision differences exits between primary THA cases with CANS and MANS; more cases with CANS are within the safe zone contrasting MANS, and there was less variation and less placement error in CANS cases. CANS can improve cup placement precision and reduce the chance of dislocation efficiently.

Distribution features of stress-strain,principle stress vectors and displacements of normal femur during gait / 中国组织工程研究

BACKGROUND:Studies demonstrated that,the probability of middle and distal end of femur bone fatigue or fracture reaches maximum when the moving loads increase or under an impact load.OBJECTIVE:To analyze the stress-strain distribution,principle stress vectors and displacements of femur during gait.METHODS:The contour curves of femur and muscles attached to femur were extracted slice by slice based on the serial CT data from a healthy male volunteer,which were used to build musculoskeletal system models.And the straight-line muscle models of the lower extremities were constructed to evaluate muscles forces and joints forces by using a multi-objective optimization method based on gait analysis.The finite element models of femur during gait were built by taking muscle forces and joint forces as boundary conditions in ANSYS 10.0 to obtain the stress-strain distribution and displacements.RESULTS AND CONCLUSION:The maximal displacement occurred on the femur head,and the maximal stress occurred in the middle and distal end of femur during the whole gait.There exists bigger tensile stress in the location of the femur neck and middle and distal end of corpus ossis femoris.The result validates the fact that femur fracture often happens at the middle and below of femur stem from the viewpoint of biomechanics.

Bicycolol tablets in treatment of patients with YMDD mutations of HBV / 中华临床感染病杂志

Objective To evaluate the clinical efficacy and safety of bicyelol tablets in treatment of hepatitis B patients infected with YMDD mutation of HBV. Methods Sixty-eight chronic hepatitis patients infected with HBV YMDD mutants and 100 patients with non-mutants HBV were enrolled in the study. All patients received bicyclol tablets orally 150 mg/d, t. i. d, for 24 weeks. Clinical symptoms, signs and adverse effects were observed, and the blood routine, liver function tests, serum HBV markers and HBV DNA loads were examined at 12th and 24th week of the study, Results After treatment for 24 weeks, the normalization rates of ALT and AST in mutant group were 79.4% ( 54/68 ) and 70. 6% (48/68) ; 11 ( 16. 2% ) patients were markedly effective and 14 (20. 6% ) were effective. Clearance rates of HBeAg and HBV DNA were 27.9% ( 17/61 ) and 17.6% ( 12/68 ), while the seroconversion rate of HBeAg was 14. 7% (9/61). The differences of the above indexes were not statistically significant between mutant group and non-mutant group. Conclusion Bicyciol can both protect liver functions and inhibit virus replication in patients infected with HBV YMDD mutants.

3D model construction for arterial vessels system of digital rat / 生物医学工程学杂志

This paper is aimed to construct a 3D model of arterial vessels system of digital rat. Firstly, the special injection medium was perfused into the arterial blood vessels of Sprague-Dawley rat; the quality of perfusion through the digital radiography system was evaluated at the same time. Then we used the sectional anatomy imaging system and achieved the digital rat atlas of sectional anatomy (sectional anatomy images were captured at 100 microm intervals, with the resolution of 4,917 x 3,446 x 24 bit and in a total of 1,464 slices). Finally, the 3D model of arterial vessels system of digital rat was constructed by segmentation, and the visualization programs were developed on Visual C+ + and Visualization ToolKit (VTK). By use of this model, the 3D microstructure of arterial system of digital rat can be obtained accurately. Remarkably, it will benefit the study of the blood vessels system on laboratory rat.