BACKGROUND: Due to individual characteristics of human body, it is difficult to well match between standard prosthesis and patient skeleton. Computer-assisted design and manufacture of individualized prosthesis can effectively prolong artificial joint lifespan and quality and reduce revision rate. However, related studies are few in China.OBJECTIVE: To explore computer-assisted design for individualized femoral head prosthesis according to three-dimensional (3D)reconstruction of CT images for improving prosthesis and affected skeleton matching.METHODS: The CT scanning image of one healthy male volunteer, with no hip joint disease, was used. His femur was scanned with GE Speed Light CT with 3.0 mm thick cross-section slices. CT 2D images were transmitted to a computer. The medical image format was translated from DICOM into bmp. Inner and external bone contours were drawn automatically or by hand and processed digitally, and then these data were downloaded into 3D Mimics8.1, and Rapidform2004 software. The 3D femoral canal model was rendered. Femur canal contours curve was downloaded into the Solidworks2004 software in the form of dxf. Femoral prosthesis was designed on the base of femoral canal contours curve.RESULTS AND CONCLUSION: The CT image was transmitted in the form of vector by a set of self-made medical image processing software. The accurate 3D femoral internal/external outline model was obtained by CT 2D image and reverse technique. Suitable femoral prosthesis was designed by means of image reverse engineering and norientation CAD. Reverse engineering and CAD provide an effective way to develop individualized prosthesis, improve the matching of prosthesis and affected skeleton, prevent prosthesis loosening and improve long-term stability.

Objective:To explore protective effect of atorvastatin on blood vessels in early stage of atherosclerosis (AS).Methods:A total of 120 patients without AS plaques,who had >2 cardiovascular risk factors and received control cardiovascular risk factors therapy,were randomly divided into four groups:control group (did not receive atorvastatin),atorvastatin 5mg group,10mg group and 20mg group (received corresponding dose of atorvastatin). All patients were followed up for six months,changes of thromboxane B2 (TXB2),6-Keto-prostaglandin F1α (6-Keto-PGF1α),brachial-ankle pulse wave velocity (baPWV),ankle brachial index (ABI)and intima-media thickness (IMT)were observed.Results:There were no significant changes in ABI and IMT between before and after treat-ment among four groups (P >0.05 all).Compared with baseline,TXB2、baPWV levels significantly rose,6-Keto-PGF1αlevel significantly decreased after treatment in control group and 5mg group;in contrast,TXB2、baPWV lev-els significantly decreased,6-Keto-PGF1αlevel significantly rose after treatment in 10mg group and 20mg group(P <0.05~ < 0.01).After treatment six-month,compared with control group and 5mg group,the TXB2 [(148.3 ± 29.2)pg/ml,(142.3±30.6)pg/ml vs.(111.5±22.8)pg/ml,(104.9 ± 17.4)pg/ml]、baPWV[(1621.1 ± 136.1) cm/s,(1597.7±125.3)cm/s vs.(1232.9±132.3)cm/s,(1178.2±155.1)cm/s]levels significantly decreased,6-Keto-PGF1α[(104.7±66.1)pg/ml,(102.2±70.3)pg/ml vs.(132.8±48.3)pg/ml,(139.1±66.3)pg/ml]level significantly rose(P <0.05~<0.01)in 10 mg group and 20 mg group.Conclusion:Atorvastatin has protective effect on blood vessels in early stage of atherosclerosis,and 10mg atorvastatin may be the minimum effective dosage to protect blood vessels.