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26 March 2011, Volume 15 Issue 13 Previous Issue    Next Issue

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Simulation of cervical disc replacement with computer assistant three-dimensional reconstruction Fang Guo-fang, Lei Gao, Luo De-min, Song Zhi-hui, Xue Hou-jun, Ao Jun, Lin Li-jun 2011, 15 (13):  2283-2286.  doi: 10.3969/j.issn.1673-8225.2011.13.002 Abstract ( 267 )   PDF (1209KB) ( 406 )   Save BACKGROUND: The cervical disc replacement requires standard operational procedure to reduce complications such as prosthetic subsidence, ectopic ossification or prosthetic dislocation. Individuated three-dimensional (3-D) reconstruction of cervical disc replacement can simulate structures of cervical disc, which is benefit for precise operation.      OBJECTIVE: To study the method of computer assistant simulating the cervical disc replacement and clinic application. METHODS: A 42 years old male with C4-5 disc protrusion was selected. 64-row CT scan was performed before replacement, which was reconstructed using 3-D geometry. The interspace between 4/5, size of C5 upper endplate, and C4 low endplate was calculated. The interspace was enlarged and a prosthesis with appreciate size was choose. The cervical disc replacement was simulated by scanCAD software and the prosthetic size was modified, and then the procedure performed in operation. RESULTS AND CONCLUSION: It could reduce placement times effectively by simulating cervical disc replacement operation and design prosthetic sizes, which was convenient for operation and obtained good clinical curative effects. 3-D reconstruction simulating operation can measure the size of endplate and interspace of inter vertebra accuracy. The data were reliable and the operation could harvest satisfactory results. Related Articles | Metrics

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Three-dimensional visual design for total hip surface replacement  Xu Kai, Chen Chun, Huang Shan-dong, Zhang Ying, Yin Qing-shui 2011, 15 (13):  2287-2290.  doi: 10.3969/j.issn.1673-8225.2011.13.003 Abstract ( 388 )   PDF (528KB) ( 602 )   Save BACKGROUND: The two-dimensional map of total hip surface replacement (THSR) can only be observed one aspect of the three-dimensional (3D) anatomical structure, but can not fully grasp the overall 3D structure. OBJECKTIVE: 3D reconstruction of THSR by Amira4.1 based on the operational platform of personal computer and to establish their digitized visible models.   METHODS: A pelvic surgery patients underwent multi-slice spiral CT scan after THSR. The location of implant form was observed. The original data were entered personal PC with .dicom, the segmented areas for structures were displayed in different colors using tools of Brush, Lasso and Magic wand, the 3D reconstruction of the hip and pelvis for obtaining 3D shape of the hip joint and the implant location of structures basing on anatomical characteristics.  RESULTS AND CONCLUSION: Structure was reconstructed. The 3D images of pelvis, hip and implant shape structure by Amira were clear and surface and volume information could be obtained. The 3D images could display perfectly the main structures of hip and implant shape and other adjacent structures by means of personal computer and software Amira4.1. The 3D structures can be multi-colored, transparent or any combination of displays. The overall showed clear physical sense after different perspectives observing. The location of the prosthesis surface morphology could be clearly observed in 3D image. THSR surface replacement prosthesis size, angle and stability could be visual particularly. Femoral head could be accurate measured. It is revealed that 3D computerized THSR reconstruction provides great value for clinical experiments, basic research and surgical planning, and its Amira4.11 software is vital for 3D reconstruction. Related Articles | Metrics

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Expression of osteoblast-related genes in bone marrow mesenchymal stem cells following total hip replacement Shen Yi, Wang Wei-li, Li Xiao-miao, Zhang Wei, Fu Xiao-dong 2011, 15 (13):  2291-2294.  doi: 10.3969/j.issn.1673-8225.2011.13.004 Abstract ( 269 )   PDF (527KB) ( 382 )   Save BACKGROUND: Prosthesis longevity after total hip replacement (THR) requires an efficient periprosthetic ossification. This includes the recruitment of bone marrow mesenchymal stem cells (BMSCs) to the site. The expression of the genes for alkaline phosphatase (ALP), Runx2, MSX2, bone morphogenetic protein 2 (BMP2), and two of its receptors (BMPR-1a and BMPR-1b) indicates the bone forming potential of a population of BMSC. We propose that a comprehensive analysis of the bone marrow osteogenic potential is helpful in predicting the strength of prosthesis fixation. OBJECTIVE: To investigate the expression of osteoblast-related genes in BMSCs derived from human bone marrow aspirate and the possible linkage of these gene expression levels with patient age, sex and body mass index (BMI) in a group of THR patients. METHODS: The study was approved by the Institutional Review Board at Providence Hospital. BMSC were prepared from bone marrow aspirate obtained from the proximal femur metaphysis during THR surgery. Twelve patients were included in this study (8 men and 4 women, aged 50-84 years, BMI 21.5-50). The isolated BMSC were culture-expanded in basal α-MEM/10% fetal bovine serum medium. Passage 1, non-confluent, undifferentiated cells were harvested for flow cytometry or for RNA isolation. Real time RT-PCR with Taqman or SYBR green was used to measure the mRNA level of genes (SOST, ALP, Runx2, MSX2, BMP2, BMPR-1a, and BMPR-1b). RESULTS AND CONCLUSION: The expression of osteoblast-related genes varied greatly in these 12 patients. Statistical analysis using SPSS showed no significant relationship between osteogenic markers and either age, sex or BMI. Linear regression analysis of the gene expression of BMP2 and BMPR-1a demonstrated a significant relationship (P < 0.01), whereas there was no significant relationship between BMP2 and BMPR-1b. There was also a significant positive association between SOST mRNA expression and ALP, MSX2 and BMPR-1a mRNA expression. Detection of the cell surface marker Stro1 by flow cytometry confirmed the mesenchymal cell characteristics of the BMSC. Theses indicated that a patient’s osteogenic potential at the time of joint replacement may determine the success of the implant fixation. Although patient’s sex, age or BMI did not correlate with osteogenic potential, all may impact the success of the implant. Moreover, given the probability that some implants will fail, the wide variation in mRNA expression of osteogenic-relevant genes also provides an opportunity to correlate gene expression with the likelihood of implant failure. Further study with these BMSC cultures should validate the use of these osteogenic markers in predicting osteoblastogenesis and potentially prosthesis success. Related Articles | Metrics

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Three-dimensional finite element analysis of pedicle screw stress following two intervertebral fusion treatments in L4/5 segment    Li Dong-zhe, Chen Fei, Kang Yi-jun 2011, 15 (13):  2295-2298.  doi: 10.3969/j.issn.1673-8225.2011.13.005 Abstract ( 327 )   PDF (566KB) ( 437 )   Save BACKGROUND: No reports regarding three-dimensional (3-D) finite element analysis of pedicle screws stress following autologous iliac crest interbody fusion combined with internal pedicle screw fixation or lumbar vertebra grating can be searched by the authors.  OBJECTIVE: To compare the stress distribution of lumbar pedicle screws of two surgical approaches, double fusion cage versus autologous iliac crest interbody fusion combined with internal pedicle screw fixation in lumbar L4-5 segment models. METHODS: Continuous horizontal scanning images of normal lumbar vertebra from a 20-year-old male volunteer that were collected by spiral CT and constructed for L4-5 segment models. 3-D finite element models of posterior lumbar internal fixation with double cage (model A) or autologous iliac crest interbody fusion (model B) were constructed. Pressure was loaded on the upper surface of L4 to simulate lumbar compressions. The stress of the pedicle screws and cage were recorded and compared. RESULTS AND CONCLUSION: 3-D finite element model of L4-5 segment internal pedicle screw fixation with two surgical approaches were validated. In every motion state, the stress of screw fixation of model B was obviously greater than that of model A (P < 0.05), and the maximum difference value located at end part of screw. The screw fixation of model B is more inclined to be fractured than model A. Related Articles | Metrics

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Toll-like receptor 2 and 4 expression in peripheral blood leukocytes of patients following prosthesis implantation  Zhang Zi-ji, Kang Yan, Zhai Qi-yi, Zhang Hao, Zhang Yang-chun, Hou Chang-he, Li Zi-qing, Sheng Pu-yi, Liao Wei-ming 2011, 15 (13):  2299-2303.  doi: 10.3969/j.issn.1673-8225.2011.13.006 Abstract ( 247 )   PDF (764KB) ( 389 )   Save BACKGROUND: Toll-like receptors (TLRs) are expressed on the surface of biofilms in loosening hip prosthesis. However, the expression changes remain unclear. OBJECTIVE: To investigate the expression of TLR 2 and 4 in leukocytes of patients undergoing joint prosthesis implantation. METHODS: Fasting blood plasma samples were harvested from elbow veins 24 hours post admission and 3 days post-operation from patients undergoing arthroplasty or arthroscopy (n=10). Cell-associated TLR 2 and 4 was measured by flow cytometry, white blood cells, C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) were tested. RESULTS AND CONCLUSION: WBC, ESR, CRP were at normal level in both groups. TLR2 and 4 were mostly expressed in monocytes of peripheral blood, with low expression levels in lymphocytes and neutrophils. The expression levels of TLR2 was significantly reduced following operation (P < 0.05), but no significant difference was observed in the expression levels of TLR4 in arthroplasty group or TLR2 and 4 in arthroscopy group between post-operation and pre-operation (P > 0.05), whereas a significant change of TLR9 expression gap was found in arthroplasty patients before and after the procedure (P < 0.05). TLR 4 expression remained unchanged (P > 0.05). The TLR2 positive expression rate in monocytes of peripheral blood was significantly lower in arthroplasty group compared with arthroscopy group (P < 0.05), but no difference was found in TLR4 expression. Results show that in the absence of clinical infection, stress and tissue damage during arthroplasty and arthroscopy do not affect TLR2 and 4 expression, but TLR2 expression was downregulated following implantation of joint prosthesis. Related Articles | Metrics

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Construction of a three-dimensional finite element model of total knee prosthesis Li Xiao-miao, Shen Yi, Wang Wei-li 2011, 15 (13):  2304-2308.  doi: 10.3969/j.issn.1673-8225.2011.13.007 Abstract ( 332 )   PDF (518KB) ( 589 )   Save BACKGROUND: Due to the complexity of the movement and stress of the knee prosthesis, it is difficult to establish a knee prosthesis model and to capture the data. The accuracy of three-dimensional (3-D) model of the knee prosthesis is affected by many factors. OBJECTIVE: To establish 3-D finite element model of total knee prosthesis. METHODS: 3-D scanning technology was used to capture the image data. Geomagic and Abaqus software was utilized to rebuild 3-D total knee prosthesis model based on the scanned images and image data. It is discussed to improve the accuracy, the opening and the efficiency of the reconstruction of the 3-D finite element model. RESULTS AND CONCLUSION: The 3-D finite element model of knee prosthesis was successfully established by Geomagic and Abaqus software based on the scanned images and image data. Compared with the previews method of the knee prosthesis model reconstruction, the design of this new model is more accurate and flexible. Especially, it simplifies the procedure of the finite element analysis. And the possibility for joint surgeons to participate in building this model is increased. A more simple and accurate knee prosthesis finite model could be provided to the clinics. Related Articles | Metrics

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Computer-aided personalized anatomic plate of the distal femur Ren Long-tao, Zhang Yun-peng, Guo Zhi-jian, Bu Xiang-kun, Lin Shu-zhong 2011, 15 (13):  2309-2312.  doi: 10.3969/j.issn.1673-8225.2011.13.008 Abstract ( 434 )   PDF (489KB) ( 612 )   Save BACKGROUND: The existing anatomic plates are lack of personalization. OBJECTIVE: To establish a three-dimensional solid model of distal femoral fracture based on CT scanning data and to design a solid model of personalized anatomic plate. METHODS: One case of male patient with distal femoral fracture was used in the experiment, and the raw data of selected regions was obtained through the thin slices CT scan. The data was saved in Dicom format and exported into the Mimics software, and then a solid model of distal femoral fractures was obtained. The model was saved in IGES format, and imported into Geomagic software, transformed IGES point cloud data into polygon model and mesh model of the structure, finally the closed NURBS surface model was obtained. The femur surface model was filed into UG software in IGES format, selected the best surface fitting with the plate according to surgical experience and demand on the femur surface plate. RESULTS AND CONCLUSION: ①A three-dimensional solid model of complex distal femoral fracture was established. ②A three-dimensional solid model of personalized anatomic plate which has a good facial fit and a special design of screw holes was established. ③The distal femoral personalized anatomic plate model and distal femur model were machined. The profile of model was realistic and closed to the normal, which has best surface fitting and special design of screw holes. Related Articles | Metrics

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Dual atlantoaxial pedicle placement using spinal navigation surgery robot  Zhang Chun-lin, Zhu Hong-he, Miao Sen, Wang Zheng, Zhang Chang-sheng 2011, 15 (13):  2313-2316.  doi: 10.3969/j.issn.1673-8225.2011.13.009 Abstract ( 319 )   PDF (565KB) ( 513 )   Save BACKGROUND: Atlantoaxial pedicle screw is thought to be the most stable instrumentation for reconstructive surgery of the cervical spine. However, because of the unresolved and inherent risk of neurovascular injuries due to screw perforation, it remains not widespread nowadays despite the excellent biomechanical property. The accuracy of atlantoaxial pedicle screw placement needs to be improved. OBJECTIVE: To explore the principle of spinal surgical navigation surgery robot atlantoaxial transpedicular dual placement with the aim of establishing a high accurate and easily operation atlantoaxial transpedicular dual placement technique. METHODS: Prior to surgery, on CT scanning image bisecting atlantoaxial pedicle in superior/inferior, each point was selected on both sides of sagittal line respectively, which located on vertebra arc-shaped epiphyseal line. The line segment across the above two points was named tranverse line (TL). The midline cuts TL and the line tangent to the furthest point of at the back of atlantoaxial respectively, and the line segment across the two points was named perpendicular line (PL), thus TL and PL which have known length and orthogonality were set on vertebra. Intraoperatively, one tranverse line and one perpendicular line with the same length to TL and PL respectively were set in vitro on dual placement manipulator. Under X-ray lateral fluoroscopy, the two tranverse lines and two perpendicular lines were matched respectively, the tip of manipulator’s registration arm contact tightly the surface of vertebra, accordingly, atlantoaxial sagittal plane, coronal plane, horizontal plane were confirmed. The length between both guide-wires’ tip was set equally to the length of both entry points, the angle between the centre axis line of pedicle and the midline equally to preoperative measurements, dual placement along the centre axis line of pedicle can be conducted with spinal navigation surgery robot with real-time monitoring. RESULTS AND CONCLUSION: With the application of spinal navigation surgery robot to dual placement on atlantoaxial vertebra, when inside and outside traverse line, perpendicular line were matched respectively, and the tip of manipulator`s registration arm contact tightly arc-shaped surface of vertebra, the tips of both guide-wires locate nowhere but the entry points of both pedicles. With real-time monitoring, dual placement along the center axis line of pedicle can be performed with spinal navigation surgery robot, which can provide accurate implantation of atlantoaxial placement. Related Articles | Metrics

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Unilateral pedicle screw fixation with lumbar interbody infusion for adjacent segment degeneration Shao Gao-hai, Jiao Chun-yan, Yu Yu, Zhong Bin, Li Bo 2011, 15 (13):  2317-2321.  doi: 10.3969/j.issn.1673-8225.2011.13.010 Abstract ( 259 )   PDF (619KB) ( 523 )   Save BACKGROUND: There are no reports addressing effects of unilateral pedicle screw plus cage internal fixation on adjacent segment degeneration in the treatment of lumbar degenerative disease. OBJECTIVE: To review the effects of unilateral pedicle screw plus cage internal fixation on adjacent segment degeneration in the treatment of lumbar degenerative disease. METHODS: From 2006 to 2009, 22 patients with partial lumbar spinal stenosis, lumbar instability, and lumbar intervertebral disc herniation received unilateral pedicle screw plus cage internal fixation. X-ray and magnetic resonance imaging (MRI) examinations were performed at 3, 6, 12, 20 months after treatment as well as at 3 and 6 months after fixated screws were removed. Based on X-ray films, height of intervertebral space was measured using angle bisectrix method. MRI examination was performed for observation of disc nucleus pulposus degeneration. RESULTS AND CONCLUSION: During the follow-up, all symptoms related to spinal stenosis and nerve root disappeared, and no new clinical symptoms occurred. The height of intervertebral space (mm) was 7.420±0.035 4, 7.426 6±0.036 9, 7.453 3±0.036 9, 7.516 6±0.036 9, 7.430 8±0.036 9, respectively, before infusion, at 3, 6, 12 and 20 months after infusion (P > 0.05). Fixation fusion adjacent disc nucleus pulposus in upper T2-weighted images had no apparent degeneration. It is indicated that the unilateral pedicle screw plus interbody infusion could effectively prevent adjacent segment degeneration in the treatment of partial lumbar intervertebral degenerative disease. Related Articles | Metrics

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Biomechanical tests and clinical application evaluation of advanced humeral retrograde intramedullary nail Xiong Ying, Wang Da-xing, Liu Bai-lian, Li Qun-hui, Jia Fu, Zhang Zhong-zi 2011, 15 (13):  2322-2326.  doi: 10.3969/j.issn.1673-8225.2011.13.011 Abstract ( 326 )   PDF (651KB) ( 536 )   Save BACKGROUND: The humeral auto-locked intramedullary nail, designed by Yanan Hospital of Kunming Medical University, exhibits several advantages over previous domestic locked intramedullary nails. However, anterograde screwing-type intramedullary nail and traditional auto-locked intramedullary nail induce rotator cuff injury and dysfunction of shoulder joint. Retrograde intramedullary nail solves these problems. OBJECTIVE: To improve the retrograde intramedullary nail based on humeral bone dissection to benefit clinical application. METHODS: According to humeral bone anatomic characteristics, related biomechanical tests were performed using humeral samples from corpse. Retrograde intramedullary nail was used to treat 73 patients with fracture of humerus. The resistance of axial compression, extension, torsion, blending were compared, and clinical effects were observed. RESULTS AND CONCLUSION: The retrograde intramedullary nail exhibited advantages in resisting axial compression, extension, torsion, and blending compared with previous existed nails (P < 0.01). The patients were followed up for 3-48 months, and healed well. No infection, nail breakage, or loosening occurred. Results showed that the advanced retrograde intramedullary nail is reasonable in biomechanical tests, with simple operation, few complications. It should be used widely in clinic. Related Articles | Metrics

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A method of intra-operative spine fast correction based on 2D/3D registration Zeng Ling, Yu Wei-wei, Xi Ping 2011, 15 (13):  2327-2330.  doi: 10.3969/j.issn.1673-8225.2011.13.012 Abstract ( 350 )   PDF (608KB) ( 466 )   Save BACKGROUND: The preoperative three-dimensional (3D) diagnosis and treatment. As patient’s posture changes, the intra-operative shape of spine is deferent form the preoperative. So the preoperative images can not reflect the intra-operative situation. And doctor can not ensure the smooth implementation of the operation. OBJECTIVE: To correct preoperative spine models using intra-operative image. METHODS: This paper presented an approach based on 2D/3D registration to correct preoperative images during operation. We use digitally reconstructed radiograph (DRR) to register CT to X-ray image. Then complete the feature registrations of all independent vertebra segments between intra-operative and preoperative X-ray images. The results of above registrations are exploited to fast correct the preoperative spine models. RESULTS AND CONCLUSION: Using marked cervical spine specimens for experiment, the deviation of the spine model can be basically eliminated after correction. The error between intra-operative and corrected preoperative spine model is less than 1mm. And clinical requirements can be met. Related Articles | Metrics

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Computer-assisted preoperative calculation of the orthopaedic rod length for patients with adolescent idiopathic scoliosis Zhou Zhong-jie, Liu Li-min, Song Yue-ming 2011, 15 (13):  2331-2334.  doi: 10.3969/j.issn.1673-8225.2011.13.013 Abstract ( 335 )   PDF (523KB) ( 376 )   Save BACKGROUND: Surgeons usually need to estimate the rod length according to the feature of the deformity and the length of the rod model made before the correction. But such estimation is not precise. OBJECTIVE: To calculate preoperatively the length of the rod for patients with adolescent idiopathic scoliosis (AIS) using computer and to evaluate the validity and accuracy of this method. METHODS: The spinal spiral CT of the patients with AIS was manipulated by the MIMICS software to reconstruct a three-dimensional model of all the vertebrae needing to be corrected. The vertebrae’s positions were adjusted to mimic the orthopaedic result of the operation, and the length of the orthopaedic rod can be calculated using short straight line by the software’s measuring tool. Seven patients were selected. The length of the orthopedic rod was calculated by MIMICS software and traditional method, anterior and posterior position X-ray of vertebral column were done postoperatively to measure the ideal length of the orthopaedic rod to evaluate the accuracy of the method. RESULTS AND CONCLUSION: For validity evaluation, the interobserver variability was (2.492±2.089) mm, and r=0.986, P=0.000 for the intra observer variability. The rod length measured by the software was (4.23±3.84) mm longer than the ideal length, while the length measured by the traditional method was (9.32±5.23) mm longer. The P value was 0.021, and the difference was statistically significant. The method of calculating preoperatively the length of the orthopaedic rod for patients with AIS using MIMICS software has good validity and reproducibility; this method also has good accuracy, which can be put into practical use. Related Articles | Metrics

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Finite element analysis of the intervertebral disc during lumbar obligue-pulling manipulation Xu Hai-tao, Li Song, Liu Lan, Lai Qiu-lian, Luo Xiao-wei, Xu Da-chuan, Li Yi-kai 2011, 15 (13):  2335-2338.  doi: 10.3969/j.issn.1673-8225.2011.13.014 Abstract ( 362 )   PDF (543KB) ( 659 )   Save BACKGROUND: Traditional Chinese manipulation maneuver is researched using computer technology and finite element method, which can explain the action mechanism, indication and contraindication of manipulation and provide objective, scientific, theoretical basis for clinical lumbar obligue-pulling manipulation.  OBJECTIVE: To study the trait of displacement and intra-stress distribution of intervertebral disc during lumbar obligue-pulling manipulation. METHODS: 3D finite element model of L4-5 segments were constructed based on normal lumbar CT images with Mimics software system. The lumbar obligue-pulling manipulation was decomposed by principium of manipulation. The parameter of mechanics was analyzed with the finite element system. The change of intra-stress distribution and displacement in lumbar intervertebral disc were displayed simultaneous during simulating manipulation. RESULTS AND CONCLUSION: The intra-stress of posterior area was smaller than that of intervertebral disc during the lumbar obligue-pulling manipulation. There was a palinal vector from center of the intervertebral disc to the right, which distorted the intervertebral disc. The lumbar obligue-pulling manipulation is safe to the intervertebral disc, and it is more rational for manipulation in the healthy side. The manipulation is not applicable to lumbar spinal stenosis. Related Articles | Metrics

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Construction and analysis of a finite-element model of patella fracture fixed with AO tensile force girdle Xu Hong-zhang, Yu Bin 2011, 15 (13):  2339-2344.  doi: 10.3969/j.issn.1673-8225.2011.13.015 Abstract ( 324 )   PDF (570KB) ( 1203 )   Save BACKGROUND: Currently, most of biomechanical research about internal fixation of patellar fracture has been carried out by corpse. Few researchers carried out it using modern finite element method. OBJECTIVE: To establish the finite element model of patella fracture fixed with AO tensile force girdle and to perfore finite element mechano-analysis. METHODS: An adult female volunteer was selected, underwent a lamellar computed tomography (CT) scan on the lower extremity, extract right patella’s polylines by Mimics10.01 software and construct geometrical models. Then the geometrical model was imported into PRO/E 2.0 software, to simulate bone fracture by intersected function of PRO/E 2.0 software and generate two bent Kirschner wires and annular steel-wire, rebuild 3D model of patella fracture fixed with AO tensile force girdle. After that, the model was imported into the ANSYS software to constructe 3D finite-element models that analyzing displacement and deformation features simulating patellofemoral joint under 600 N loading at 90° knee bending.   RESULTS AND CONCLUSION: The AO tensile force girdle could force patella fracture in many ways, and opposed to tensile force of musculus quadriceps fexoris. The finite element analytic result coincides with biomechanical result. The 3D finite-element model of patella fracture fixed with AO tensile force girdle was scientific, which is beneficial to better understanding of the biomechanical principle about patella fracture fixed with AO tensile force girdle and provides clinical instruction. Related Articles | Metrics

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Three-dimensional reconstruction of dentures based on general CAD technology Zhu Yu, Wu Xiu-juan, Lü Jing-jing, Ni Hong-jun, Huang Ming-yu 2011, 15 (13):  2345-2348.  doi: 10.3969/j.issn.1673-8225.2011.13.016 Abstract ( 405 )   PDF (516KB) ( 926 )   Save BACKGROUND: The pressure is fully on the gum because complete dentures lack supports from the teeth. Gum inflammation and metal allergies often occur because of gum wearing when patients chew. Doctors must test the adaptability of the material on dentures firstly before installing dentures for patients. OBJECTIVE: To reconstruct three-dimensional model of dentures after running-in. METHODS: The three-dimensional data of complete dentures following running-in were collected by laser scanners and other digital acquisition equipment. The pre-processing, such as noise reduction, data filtering, data reduction and repair of the missing data, were performed using reverse software, and wrapped into triangular surface. The model was reconstructed using Pro/E or other 3D design software. RESULTS AND CONCLUSION: The three-dimensional data of complete dentures following running-in were collected by laser scanners, CT and other digital acquisition equipment. The pre-processing, such as noise reduction, data filtering, data reduction and repair of the missing data, were performed, and the curve model was extracted. The reconstruction of model was realized using the Pro/E or other 3D design software, which can provide digital information for making dentures. Copies of dentures can be obtained by rapid manufacturing. Complete dentures after running-in save time, reduce doctors’ labor intensity, decrease the risk for allergy to materials, shorten running-in time between patients and dentures, and reduce patient’s suffering. Related Articles | Metrics

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The finite element analysis of interface stress distribution for TM implant Wang Su-wen, Song Guang-bao, Zeng Shu-guang, Yao Xiao-hu, Sun Yu-gang 2011, 15 (13):  2349-2353.  doi: 10.3969/j.issn.1673-8225.2011.13.017 Abstract ( 281 )   PDF (820KB) ( 558 )   Save BACKGROUND: The morphology of implant is one of important factors determining interface stress distribution for TM implant. The TM implant bone interface stress distribution of comply with anatomic form of human normal jaw bone, which has an instructional significance for selection and design of implant of clinicians. OBJECTIVE: To observe the characteristics of the stress distribution of TM implant and its surrounding bone tissue under concentrated load. METHODS: Three-dimensional solid model of mandible has been established from two-dimensional CT pictures through reverse engineering technology. Based on three TM implants with different conical degrees, three different finite element models consisting of corresponding implants and true models of bone in B/2 type were established. The stress distribution characteristics on the bone interface of TM implant and under two different loadings were investigated by using of finite element technology. RESULTS AND CONCLUSION: The compact bone around TM implant related to a high conical degree bears smaller stresses under vertical loading, while compact bone around TM implant and cancellated bone related to a high conical degree bears the bigger stresses under oblique loading. Besides, stress concentration occurs in the contact interface of upper compact bone and implant, and the bottom of spongy bone in the neck of implant. The stress distribution of bone interface of implant was significantly higher in oblique loading condition than that in vertical loading. Bone interface of TM implant varied from 1/2 length showed a good characteristic of stress distribution under vertical loading. Related Articles | Metrics

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Three-dimensional finite element analysis of implants with different crown-to-root ratio for the mandibular first molar Jin Ding, Du Yang, Qu Zhi, Wang Zhi-ying 2011, 15 (13):  2354-2357.  doi: 10.3969/j.issn.1673-8225.2011.13.018 Abstract ( 494 )   PDF (567KB) ( 634 )   Save BACKGROUND: Mandibular first molar is clinically more common oral diseases. Clinically, the first molar for a variety of repair methods, compared to the traditional fixed bridge, implant because of their chewing efficiency, less damage to the adjacent teeth and gradually began to widely adopt. Ability to support the implant is designed to be taken into account, together with the supporting tissue implant into a mechanical exercise load to bear chewing function structure, this structure is not destroyed to achieve long-term stability to function, must be consistent with biomechanical principles. OBJECTIVE: Dentition lack is one of common oral diseases, it has become an important oral developed direction by planting repair to restore missing teeth by common methods of cultivation including a single implant repair and crown a single fixed bridge repair and so on. Different cap ratios of restoration implants have become an important factor influencing the long-term effects for restoration implants. Therefore, through CT scan this issue made two solid models by computer, which embrace normal human mandible and mandibular dentition three-dimensionally. And on the basis of solid models, it generated finite element models by large-scale finite element analysis software. We compared the stress distribution of implants of different crown-to-root ratios. Thus, it laid the theoretical foundation for the lack of clinical dental restoration. METHODS: This issue acquired general outline of the mandible and mandibular dentition by CT technology. It fitted overall image according to graphics features by picture control system, and then generated cloud chart by computer software. We proceed three-dimensional reconstruction according to the cloud chart, as a result, we gained three-dimensional finite element models of mandible and mandibular dentition. Moreover, we established three-dimensional models of two-highest single-root implants to repair the mandibular first molar. To apply Hyperwprk8.0 and Ansys11.0, we established mandibular implant prosthesis models of different crown-to-root ratio implants, and finished the crown restoration. On the basis of the simulated same direction load, we compared the stress distribution of implants with different crown-to-root ratios. RESULTS AND CONCLUSION: We gained three-dimensional finite element models of mandible and mandibular dentition and mandibular prosthesis models of different crown-to-root ratios. When parallel to the direction of the implant was forced, the implant apical and around bone tissue were concentration zone of stress. The influences of different crown-to-root ratios are faint for jaw force in the direction of implant embedded, but great in the buccolingual direction. Therefore, the stability of the dental implant is considered in the horizontal direction. If space conditions are not permitted, the posterior area could be considered after a dental implant support. Related Articles | Metrics

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Establishment of a finite element model of mandible bilateral-sagitta-split-ramus-osteotomy with Mimics software Wang Rui-chun, Guan Zhen-qun, Liu Feng, Huang Di-yan 2011, 15 (13):  2358-2361.  doi: 10.3969/j.issn.1673-8225.2011.13.019 Abstract ( 316 )   PDF (663KB) ( 525 )   Save BACKGROUND: Bilateral-sagitta-split-ramus-osteotomy (BSSRO) is a useful method for orthognathic surgery; finite element method is an important approach in studying BSSRO biomechanics. OBJECTIVE: To explore an easier and more precise method for establishment of the three-dimensional (3D) finite element model of mandible BSSRO and lays foundation for the research of biomechanics after BSSRO. METHODS: CT faultage image was analyzed by thin-layer CT, Dicom standard and Mimics software combined with MSC.Patran software. RESULTS AND CONCLUSION: A 3D finite element model of mandible BSSRO was established. Dicom standard and Mimics software were used to obtain the CT images and write the digital data to MSC. Patran software directly, which increased the efficiency of establishment of the 3D finite element model. It is indicated that the application of thin-layer CT and Dicom standard make the establishment of finite element model more precise. Meanwhile, BSSRO was directly established by Mimics software, the application of Mimics software can improve the efficiency of establishment of the 3D finite element model to a large extent, and lays foundation for biomechanics analysis. Related Articles | Metrics

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Selection and application of multi-slice CT 3D reconstruction techniques in assisting mini-implant ahchorage implant surgery Chen Jing-yi, Wu Xiao-wei, Zhang Hong-gang, Jiao Jian-jun, Zhang Xue-qiang, Yao Chuan-chen 2011, 15 (13):  2362-2365.  doi: 10.3969/j.issn.1673-8225.2011.13.020 Abstract ( 369 )   PDF (530KB) ( 467 )   Save BACKGROUND: The key method to improve the stability of miniscrew orthodontic anchorage system is accurate preoperative bone mass evaluation in the implant region. Routine 2D image examinations such as periapical radiography and panoramic tomography and lateral cephalometric radiography have limitations. OBJECTIVE: To analyze the traits and advantages of various multi-slice CT (MSCT) reconstruction images in assisting miniscrew anchorage surgery to improve the stability of miniscrew. METHODS: Preplant MSCT scanning and various images reconstruction were made and helped to exam the peri-implant bone mass and density and the anatomical relation to important structures comprehensively. According the implant anchorage angles in MSCT images accurately designed by computer, the tunnel-type surgical template was made to assist 32 miniscrews implant surgery. Then the skulls of two pigs were rescanned by MSCT. After dissected the pig alveolar process, the MSCT preoperative designed angles, the MSCT postoperative measured angles and the measured angles of anatomic bone samples were analyzed statistically. RESULTS AND CONCLUSION: The 32 miniscrews were implanted successfully. They did not damage dental roots or surrounding important structures. Compared MSCT preoperative designed angles with MSCT postoperative measured angles and anatomic bone samples measured angles, there were no significant differences in axial sections or cross-sections (P > 0.05), and the r concordance correlations were very good. Results show that MSCT can provide accurate and abundant image information. Exact selection and application can help to fully attain the objects of imaging examination on miniscrew anchorage surgery, thus improving the success rate of miniscrews. Related Articles | Metrics

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Vertebroplasty injected with bone cement versus non-operative treatment for osteoporotic vertebral compression fractures: A Meta-analysis Xu Jian-cheng, Bai Jing-ping, Xilin Baoleri, He Zu-sheng, Jiang Ren-bing, Huang Wei-min 2011, 15 (13):  2366-2370.  doi: 10.3969/j.issn.1673-8225.2011.13.021 Abstract ( 282 )   PDF (648KB) ( 674 )   Save BACKGROUND: Vertebroplasty injected with bone cement or percutaneous vertebroplasty as the minimally invasive technique in treatment of osteoporotic vertebral compression fracture. Some case reports and non-randomized controlled study revealed that vertebroplasty has an effect on pain caused by osteoporotic vertebral compression fractures. However, these studies are based on retrospective case analysis, lack of high-quality randomized controlled study. OBJECTIVE: To evaluate the effectiveness of Meta-analysis method on vertebroplasty versus non-operative in treatment of osteoporotic vertebral compression fractures. METHODS: A computer-based online search of Cochrane Library (the 4th period, 2010), PubMed database (1966/2011-11), EMBASE database (1974/2010-11), CBM database (1978/2010-11), CNKI database (1994/2010-11), and Wanfang database (1997/2010-11). Randomized controlled trials of vertebroplasty versus non-operative in treatment of osteoporotic vertebral compression fractures were included, and underwent strict quality assessment according to Cochrane Handbook 5.0. Meta-analysis was performed by RevMan 5.0.1 software. RESULTS AND CONCLUSION: A total of 445 cases in 4 randomized controlled trials were included. Meta-analysis results showed that vertebroplasty in pain relief is more obvious than that in conservative treatment at 1, 4, 24, 48 weeks follow-up, but there were no significant differences in incidence of new fracture between the two groups. Compared with the placebo, there is no significant advantage for the vertebroplasty over the placebo in pain relief, the improvement of functional activities of waist, and quality of life. The above conclusions still needs more high-quality randomized controlled trails to be verified owing to the limitations of the number and quality of systematic review included studies. Related Articles | Metrics

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Artificial femoral head replacement versus dynamic hip screws in elderly intertrochanteric fracture: A meta analysis He Qi-xin, Xie Guang-zhong 2011, 15 (13):  2371-2375.  doi: 10.3969/j.issn.1673-8225.2011.13.022 Abstract ( 378 )   PDF (536KB) ( 464 )   Save BACKGROUND: Artificial femoral head replacement is superior to dynamic hip screws (DHS) in treating elderly intertrochanteric fracture. OBJECTIVE: To compare the clinical effects between artificial femoral head replacement and DHS in treating elderly intertrochanteric fracture.  METHODS: The databases of PubMed, Medline, CNKI and VIP were searched online. All the trials comparing artificial femoral head replacement with dynamic hip screws in elderly intertrochanteric fracture were included. Data of baseline information, operation time, bleeding amounts, hospitalization time, weight-bearing time, complication rate, Harris score and the excellent rate were collected and meta-analyzed with RevMan5.0.25.  RESULTS AND CONCLUSION: Eleven trials with 1 227 patients were included, including 587 artificial femoral head replacement and 640 DHS. The meta-analysis showed that there were no significant differences in operation time and bleeding amounts between the two groups. However, the hospitalization time was shorter [RR=-2.56, 95%CI (-3.27, -1.85), P < 0.000 01], the weight-bearing time was earlier [RR=-50.09, 95%CI (-62.73, -37.45), P < 0.000 01], the complication rate was lower [RR=0.39, 95%CI (0.28, 0.55), P < 0.000 01], the Harris score was higher [RR=4.19, 95%CI (3.04, 5.34), P < 0.000 01] and the excellent rate at final follow-up was higher [RR=2.25, 95%CI (1.49, 3.40), P=0.000 1] in the artificial femoral head replacement group. Results indicate that artificial femoral head replacement would not increase the operation time and bleeding amounts, but would shorten the hospitalization time and weight-bearing time, reduce the complication rate and improve the function. Artificial femoral head replacement is recommended in treating elderly intertrochanteric fracture due to its obvious superiority. Related Articles | Metrics

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Three-dimensional reconstruction and deformation simulation of human organ based on web Zhang Xiao-ping, Zhang Xiao-yong, Wang Jun-ze 2011, 15 (13):  2376-2380.  doi: 10.3969/j.issn.1673-8225.2011.13.023 Abstract ( 358 )   PDF (618KB) ( 762 )   Save BACKGROUND: It uses computer image processing technology and data visualization technology to reconstruct the human organ with selected mathematical model.  OBJECTIVE: To simulate the three-dimensional model of focus full of the physical properties of actual object on screen using CT based on human organ deformation and simulation and interaction. METHODS: Image processing technology was used to process the CT of kidney and the date points of kidney contour were extracted. Through the communication between EAI (External Authoring Interface) of VRML and Java-Applet, the simulation of kidney can be achieved deformed under any external force at any position. RESULTS AND CONCLUSION: Three-dimensional reconstruction of human kidney was realized based on CT image, and deformation simulation was realized using mass-spring model. Using JAVA and VRML, the kidney was simulated, and the deformation condition was displayed after inputting sequence of size and position of applied force. This study only investigated extension and extrusion, but other deformation can be also realized. This approach gives a new idea for realizing the interaction of virtual surgery system about human organ on web. Related Articles | Metrics

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Construction and verification of the foot finite element model Li Hai-yan, Ding Cheng, Ruan Shi-jie, He Li-juan 2011, 15 (13):  2381-2384.  doi: 10.3969/j.issn.1673-8225.2011.13.024 Abstract ( 412 )   PDF (625KB) ( 507 )   Save BACKGROUND: At present, the foot model was mostly automatic tetrahedral mesh finite element model. Although the automatically partition technology of tetrahedral grid has brought great convenience to the automatically partition of three-dimensional entitative finite element mesh, the mechanical properties are poor. OBJECTIVE: To construct finite element model of the foot with hexahedral mesh based on CT images. METHODS: The CT data of normal male foot was selected, using Mimics software to reconstruct the geometric model of the foot, and using NURBS surfaces knot insertion algorithm to refine the geometric model. A high degree of biological simulation finite element model of the human foot was established, using Pam-crash software to undergo collision and simulation analysis. RESULTS AND CONCLUSION: The results of simulation accorded with results of cadaveric experiments, which showed a good validity of the model. Experiment constructed hexahedral mesh finite element model of the foot based on CT images, foot muscle, tendon and skin were added, thus it could response more realistic to the anatomical structure of the foot, and improved the quality of the finite element model, more effective to study mechanism of the foot injury, so as to provide fundamental data for improve vehicle safety design reference. Related Articles | Metrics

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System design for an intraoperative peritoneal hyperthermia chemotherapy machine based on computational fluid dynamics simulation Fu Yan-ling, Sheng Xin-jun, Yang Qiu-meng, Zhu Xiang-yang 2011, 15 (13):  2385-2389.  doi: 10.3969/j.issn.1673-8225.2011.13.025 Abstract ( 311 )   PDF (769KB) ( 681 )   Save BACKGROUND: Introperative peritoneal hyperthermia chemotherapy (IPHC) using interaction of regional high-dose chemotherapy and hyperthermia induce apoptosis and necrosis of intraoperative tumor cells. Its clinical effect has been confirmed around the world. However, current IPHC machine has low control accuracy and its therapeutic efficacy is not ideal. OBJECTIVE: To design a kind of IPHC machine system based on F2812 and computational fluid dynamics (CFD) simulation and optimize its parameters to have best temperature control and therapeutic effects. METHODS: Control system of heating and circulation based on DSP F2812 had fast response and high temperature control accuracy. Optimize parameter could be obtained by tuning PID algorithm. CFD simulation of Intraperitoneal temperature field and velocity vector field were calculated by FLUENT. Three kind of introperative peritoneal piping mode were compared to find the best strategy. Peritoneal temperature distribution was given. RESULTS AND CONCLUSION: The temperature acquisition and control module was designed, and the temperature control accuracy was ±0.3 ℃. Optimization results showed that 3 inflows and 2 outflows with closed cavity can meet operation requirements. Peritoneal temperature distribution in 3D is also given. Related Articles | Metrics

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Flow control of intra aorta pump based on heart rate Gu Kai-yun, Gao Bin, Chang Yu 2011, 15 (13):  2390-2393.  doi: 10.3969/j.issn.1673-8225.2011.13.026 Abstract ( 358 )   PDF (486KB) ( 630 )   Save BACKGROUND: With the development of the research and application of artificial heart, people hope that it can accord with physiological mechanism of natural heart and meet demand of human body in device performance. OBJECTIVE: For the control of intra-aorta pump, this paper proposed the flow control algorithm based on heart rate. METHODS: Utilizing the PID control algorithm to maintain the output flow satisfy the physical needs of patients. Simulation results show the accuracy of the algorithm to achieve fast and stable flow blood pump output. RESULTS AND CONCLUSION: When the heart rate was of 75 times per minute, blood pump flow rate could reach 5.01 L/min; blood pump flow gradually increased with the heart rate when the heart rate was in the range from 50 to 120 times per minute; blood pump kept constant flow state when the heart rate less than 50 times per minute or more than 120 times per minute. Through PID control, the actual flow rate tracks the reference one within 0.1 s. The blood pump flow model based on heart rate can reflect the needs of human blood flow. The control algorithm can achieve stable flow blood pump output, to keep pace human needs of patients. Related Articles | Metrics

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Fetal electrocardiogram extraction based on independent component and wavelet analyses Du Yan-qin, Huang Hua 2011, 15 (13):  2394-2397.  doi: 10.3969/j.issn.1673-8225.2011.13.027 Abstract ( 319 )   PDF (533KB) ( 554 )   Save BACKGROUND: In the fetal electrocardiogram (ECG) acquisition process, it is interfered by maternal ECG and other noise. It becomes important that how to extract rapidly and effectively fetal ECG. OBJECTIVE: Using independent component analysis and wavelet analysis to isolate maternal detection signals to obtain effective fetal ECG. METHODS: Fetal ECG was extracted using the method combining independent component analysis and wavelet analysis. First, noised signals underwent wavelet transform to eliminate strange signals and non-stable random signals, followed by rapid independent component analysis. RESULTS AND CONCLUSION: Fetal ECG collection was interfered by maternal ECG and other noise, but these signals are random, not related, and can be considered independent of each other. Each independent component could be extracted effectively by using the method combining independent component analysis and wavelet analysis. Experiments show that the method is effective. Related Articles | Metrics

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Feasibility of color measurement for iris using digital camera Zheng Guo-wei, Song Yan, Lu Lan 2011, 15 (13):  2398-2402.  doi: 10.3969/j.issn.1673-8225.2011.13.028 Abstract ( 368 )   PDF (679KB) ( 517 )   Save BACKGROUND: Because of individual differences in the natural iris color and colorimetric method, colorimetric environment and the operator, color Selection results often do not make a patient satisfaction.  OBJECTIVE: To evaluate the reliability and reasonability of iris color matching by using the digital camera. METHODS: The irises from 148 volunteers aged between 24 to 49 years were recorded by a digital camera in studio environment (D65 standard illuminant). Photographs were taken under a set exposure parameters (AE f/2.8, l/45 s, ISO 100) and saved in RAW image file format. The characteristics of color of the tested iris were visually observed, and the color values were obtained from the digital images using Camera RAW for Adobe Photoshop 7.0. Through partial color picking analysis by Photoshop 7.0 to exhibit different levels and the H, S and B value which compared by using HSB Model sliders. All data were analyzed in descriptive statistics and compared in χ2 analysis using SPSS 13.0 software package.  RESULTS AND CONCLUSION: 148 patients for lack of a single eye with little chromatism that was not easily detected by naked eyes were randomly selected and HSB model was applied for color matching, of these, 141 enjoyed good color quality which is consistent with that of healthy eye; 4 were slightly different from other iris in terms of their color quality and restoration which can be identified when being looked at closely:3 are substantially different from neighboring iris. Based on the Munsell H.V.C. color system, by application of HSB model and digital cameras computers and certain software, to test and analyze different colors is a scientific and quantitative method which matches color quickly and conveniently. Also, the materials needed are easily acquired. Therefore, it is of clinical application value. Related Articles | Metrics

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Effect of the interictal spike and waves of epileptic seizure on theta oscillation in hippocampal CA1: A Gabor wavelet and Hilbert transform study Dong Guo-ya, Chen Xiao-gang, Zhou Xin-hua, Li Wen-wen, Ge Man-ling 2011, 15 (13):  2403-2407.  doi: 10.3969/j.issn.1673-8225.2011.13.029 Abstract ( 402 )   PDF (681KB) ( 753 )   Save BACKGROUND: Theta oscillation is a representative characteristic of neural activity in hippocampus and serves as the starting point for the study of epilepsy and cognition in micro-ways. OBJECTIVE: To investigate the effects of the interictal spike and waves of epileptic seizure on theta oscillation in hippocampal CA1. METHODS: The iEEG data of 8 epileptic rats and 10 patients from School of Medicine, Mediterranean University, Marseilles, France were collected, and their corresponding iEEG data without spike and waves as controls. Gabor wavelet and Hilbert transform were used for extraction of the power of theta oscillation before and after the spike waves. The outcomes of Gabor wavelet and Hilbert transform were compared. RESULTS AND CONCLUSION: Dynamic characteristics of theta power in epilepsy group: Epileptic interictal spike and waves weaken the theta oscillation power, but after a long period of spike and waves, theta oscillation power recovered. It is speculated that the brain's default network connection strength is affected by status epilepticus and may be weakened. However, the weakening of the default network is a pathological basis of cognitive decline. Related Articles | Metrics

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Segmentation of multiple sclerosis lesions in brain magnetic resonance images with modified fuzzy C-means algorithm Huang Xiao, Li Bin, Feng Qian-jin 2011, 15 (13):  2408-2411.  doi: 10.3969/j.issn.1673-8225.2011.13.030 Abstract ( 364 )   PDF (515KB) ( 384 )   Save BACKGROUND: Brain magnetic resonance image is a non-texture image, characterized as piecewise constant for the gray value of MR images. Therefore, the gray value in clustering process has tended to relatively close in the same area. OBJECTIVE: To find a modified fuzzy C-means (FCM) algorithm method to segment the multiple sclerosis (MS) automatically that can support a tool to confirm MS easily. METHODS: A novel modified FCM framework is proposed by filtering membership data sets in the iterate process of FCM. The proposed algorithm denoise by making use of the property that the probability of the neighboring pixels which belong to the same cluster are similar. RESULTS AND CONCLUSION: We test our method on brain MR T1 and T2 fluid-attenuated inversion recovery images of 10 patients with MS. The testing experiments on brain MR images show that the proposed algorithm is able to segment the images correctly, which is important to assist the diagnosis of MS in clinic. Related Articles | Metrics

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A new method for quickly correcting ring artifacts in CT image Lai Sheng-sheng, Peng Sheng-hua, Yu Xiao-e 2011, 15 (13):  2412-2415.  doi: 10.3969/j.issn.1673-8225.2011.13.031 Abstract ( 468 )   PDF (589KB) ( 789 )   Save BACKGROUND: Ring artifacts, seriously affect the CT image quality, create difficulties to post-processing of the images, and easily lead to wrong diagnosis. At present, the removal of ring artifacts is essential. OBJECTIVE: A new image correction method based on polar coordinate transformation is proposed to remove ring artifacts in CT image and to improve the precisions of post processing and quantitative analysis, as well as facilitate the diagnosis. METHODS: Firstly, the CT images with ring artifacts were processed by linear transformation, converting the gray images into floating-point types of images. Secondly, the ring artifacts in the Cartesian coordinate were transformed into the vertical line artifacts in the polar coordinate. Thirdly, designing multidimensional filters, calculated the mean and variance of each pixel after filtering, compared with the threshold value to determine the scope of artifacts. Finally, correcting the range of artifacts, and converting into gray images by coordinate transformation. RESULTS AND CONCLUSION: Designing program by Matlab 7.0, the experiment indicates that this method can correct ring artifacts in CT images quickly and effectively, and it is a image post-processing correction methods. Related Articles | Metrics

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Image reading, writing and display for DICOM files based on ITK, VTK and MFC Lü Xiao-qi, Ren Xiao-ying, Jia Dong-zheng 2011, 15 (13):  2416-2420.  doi: 10.3969/j.issn.1673-8225.2011.13.032 Abstract ( 1200 )   PDF (461KB) ( 4184 )   Save BACKGROUND: The DICOM flies include not only the image data but also a plenty of the medical information in the file header, which makes the work of the DICOM image correct reading, writing and display very important. OBJECTIVE: To make use of the advantage of the toolkit and development platform to reach a basic purpose that achieves the correct reading, writing and display of the DICOM standard image. METHODS: This article firstly integrated the ITK, VTK with MFC and then read and displayed the DICOM flies by the classes and functions offered by ITK and VTK in the integration environment. RESULTS AND CONCLUSION: This article achieved the correct reading, writing and display of the DICOM files by using the method that was mentioned in the article and a flexible, friendly, practical interface offered to users by the integration environment of ITK, VTK and MFC, and made a preliminary attempt on the software development in the integration environment and lay a good foundation for realizing more functional on this basis in medical image processing. Related Articles | Metrics

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Patella treatment in total knee arthroplasty Zhang Xin, Wang Zhi-wei 2011, 15 (13):  2421-2424.  doi: 10.3969/j.issn.1673-8225.2011.13.033 Abstract ( 626 )   PDF (595KB) ( 517 )   Save BACKGROUND: Total knee arthroplasty technique and prosthetic design have been improved with the development of clinical practice and experimental research, however, the treatment of patella is a bone of contention in total knee arthroplasty. OBJECTIVE: To analyze the features of routine patellar resurfacing, routine patellar reservation and selective patellar resurfacing in order to provide preferred plan for patellar treatment in total knee arthroplasty. METHODS: PubMed, Wanfang and VIP databases were searched by the first author with key words of “total knee arthroplasty, patellar, replacement” both in English and Chinese. Inclusive criteria: ①Papers regarding prosthetic design in total knee arthroplasty. ②Biocompatibility of total knee prosthesis. ③Patellar treatment in total knee arthroplasty. After reading titles and abstract, 32 manuscipts were included in this review. RESULTS AND CONCLUSION: For a long time, scholars have different opinions on how to treat patella in total knee arthroplasty and form three main opinions, namely, routine patellar resurfacing, routine patellar reservation and selective patellar resurfacing. Currently, how to treat patella in total knee arthroplasty still need further long-term follow-up and randomized controlled studies. Based on retrospective analysis and randomized controlled studies, degree of confidence, time duration, and evaluating criteria should be considered to make reasonable decision to guide clinical application. Related Articles | Metrics

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Utilization of virtual reality technology in acetabular surgery Wang Mei, Zhang Yue-dong, Zhang Lan-hua 2011, 15 (13):  2425-2428.  doi: 10.3969/j.issn.1673-8225.2011.13.034 Abstract ( 332 )   PDF (640KB) ( 485 )   Save BACKGROUND: At present, abroad has carried out some research and practice on the medical virtual reality technology, especially in a virtual medical simulation training and other aspects of surgery, but it does not fully meet the needs of clinical orthopedic surgery. The acetabular fractures are difficult to treat because of its complexity. Clinicians select appropriate treatment options and surgical approaches according to imaging studies, which are difficult to accurately determine the spatial three-dimensional relationship. OBJECTIVE: To review the application of virtual reality technology in acetabular surgery.  METHODS: CNKI, PubMed, Wanfang and VIP databases were searched for papers addressing application of virtual reality in acetabular surgery using key words of “finite element model, acetabular fracture, and virtual surgery” both in English and Chinese. The repetitive studies or papers with blur parameter were removed. RESULTS AND CONCLUSION: Totally 115 documents were initial searched by computer, and 32 papers were included in this review. Acetabular virtual surgery system can analyze the complex of acetabulum and simulate the actual situation, thus, provides a 3-dimensional virtual procedure for clinical operations. A virtual platform can provide guidance for making preoperative plan, which has good prospect in medical surgery teaching and simulation training. Related Articles | Metrics

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Research process and development direction of artificial nucleus pulposus  Li Hai-xia, Zou De-wei, Lu Ming 2011, 15 (13):  2429-2433.  doi: 10.3969/j.issn.1673-8225.2011.13.035 Abstract ( 322 )   PDF (680KB) ( 717 )   Save BACKGROUND: Artificial nucleus pulposus replacement is one of the best treatments for lumbar disc degeneration and reestablishing the interverteberal stability and function of sparing motion, an approved artificial material is the focus and difficult problem in current studies. OBJECTIVE: To review the methods and achievements in treating lumbar intervertebral disc protrusion, analyze the history and current situation of artificial nucleus pulposus, and to review the features of prefabricatel and in-situ polymerizated artificial nucleus pulposus. METHODS: PubMed (http://www.ncbi.nlm.nih.gov/PubMed), Wangfang (http://www.wanfangdata.com.cn) and Lumbar Intervertebral Disc Protrusion were searched by the first author using key words of “nucleus replacement, biocompatibility, disc degenerative” both in English and Chinese for documents of treating methods, material selection and implantation approaches in treating lumbar disc degeneration. Totally 90 manuscripts were searched, and 36 papers were included in this review.   RESULTS AND CONCLUSION: Two kinds of prosthesis are used in artificial nucleus pulposus replacement, namely, prefabricatel and in-situ polymerizated. The former is more similar to normal nucleus pulposus in biomechanics; however, it is thought to be arouse various complications. In-situ polymerizated material is an elastic body that polymerize and stiffen after implantation with various monomers, which can maximum reduce the surgical trauma and decline the risk of graft dislocation. But it is still need assessment. It suggest that as one of the new alternative in treating lumber disc herniation, many kinds of materials are under investigation, and have gain some early achievement. Artificial nucleus replacement is a potential surgical technique as a recruitment and improvement of traditional surgery. Related Articles | Metrics

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Anatomic basic of atlantoaxial trauma and biomechanical features of grafting fixation treatment Zhang Jin-feng, Li Shu-zhong 2011, 15 (13):  2434-2437.  doi: 10.3969/j.issn.1673-8225.2011.13.036 Abstract ( 322 )   PDF (584KB) ( 692 )   Save BACKGROUND: Atlantoaxial disease incidence increased year by year, because of its anatomical structure and the adjacent complex relationship, it plays a vital role in choosing the correct fixation for the treatment of disease. OBJECTIVE: To summarize the atlantoaxial anatomy of injury and the progress of internal fixation techniques for clinical applications. METHODS: Literatures about atlantoaxial anatomy and fixation from Wanfang and PubMed database published from 1974 to 2010 were searched by the first author. The key terms were “atlantoaxial, anatomy, internal fixation” both in English and Chinese. Papers published recently or in authoritative journals were selected. Totally 116 documents were initial searched and 28 included in this review. RESULTS AND CONCLUSION: Atlantoaxial occipitocervical migration is an important structure for construction of head rotation and flexion and extension. Because it closes to spinal cord, vertebral artery, cervical nerve and other important structures, any reason caused atlantoaxial or ligament damage can lead to atlantoaxial instability. Variously methods can treat atlantoaxial fixation, however, an appropriate technology should be selected based on anatomical characteristics of the lesion, the indications of various methods, and the operational capacity of the surgeon. Related Articles | Metrics

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Clinical values of electromyogram in evaluating lumbar disc herniation Gao Qing, Fang Shi-yuan 2011, 15 (13):  2438-2441.  doi: 10.3969/j.issn.1673-8225.2011.13.037 Abstract ( 332 )   PDF (604KB) ( 754 )   Save BACKGROUND: Electromyogram (EMG) provides an objective appreciation in diagnosis, treatment selection and evaluation of curative effect for patients with lumbar disc herniation (LDH), and has an objective, accurate and quantitative role in assessment of recovery in nerve lesions。 OBJECTIVE: To summarize the roles of EMG in diagnosis, and evaluation of curative effect for patients with LDH. METHODS: A compute-based online search of Pubmed database (1990-01/2010-10) and CNKI (1998-01/2010-10) was performed with key words “LDH, sEMG, EMG, lumbar disc herniation” in English and “LDH, electromyography” in Chinese. The articles about LDH and EMG were included. Repeated studies were excluded. RESULTS AND CONCLUSION: A total of 34 literatures were included and analyzed the roles of EMG in diagnosis, and evaluation of curative effect for patients with LDH. Routine EMG has objective effects on diagnosis, evaluation of curative effect and selection of treatment methods, and surface EMG also plays similar roles. But surface EMG is easily interfered. Therefore, extensive clinical application of surface EMG requires further investigation. Related Articles | Metrics

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Accurate three-dimensional CT reconstruction of craniofacial morphology features Jiang Jin-ling, He Yu-hong, Huang Di-yan 2011, 15 (13):  2442-2445.  doi: 10.3969/j.issn.1673-8225.2011.13.038 Abstract ( 379 )   PDF (584KB) ( 606 )   Save BACKGROUND: Orthodontic cephalometric technique is an important means for clinical diagnosis and treatment plan design of oral and maxillofacial deformities. Accurate cephalometry can offer reliable evidence for the treatment. Three-dimensional CT reconstruction technology can rebuild a clear, three-dimensional, real craniofacial anatomy. OBJECTIVE: To ssummarize the clinical application of three-dimensional reconstructed CT cephalometry in dental orthodontics, and to compare with traditional X-ray cephalometry. METHODS: A computer-based online retrieval of PubMed database (http://www.ncbi.nlm.nih.gov/pubmed/) and CNKI database (http://dlib3.cnki.net/KNS50/) from January 1996 to September 2010 was performed by the first author, using “three-dimensional cephalometry, cephalometric measurements” in English and in Chinese as the search key words. Studies regarding orthodontic cephalometric measurements were included, while duplicate or out-dated studies were excluded. RESULTS AND CONCLUSION: Totally 114 paper were screened out by computer, 27 documents of which were involved for analysis according to inclusion and exclusion criteria. Three-dimensional CT reconstruction technology as an ideal method of cephalometry, has been widely used in clinical practice due to the high efficiency, accuracy and fast speed. Three-dimensional reconstruction, measurement and analysis system of soft and hard tissues will eventually replace the existing two-dimensional cephalometric analysis system with its powerful advantages. Related Articles | Metrics

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Characteristics of Modic changes in the cervical spine and its relationship with cervical degeneration Li Ji-gang, Yang Hui-lin, Zhu Ruo-fu,Zhang Lei 2011, 15 (13):  2446-2449.  doi: 10.3969/j.issn.1673-8225.2011.13.039 Abstract ( 446 )   PDF (572KB) ( 701 )   Save BACKGROUND: The distribution and characteristics of Modic changes in lumbar spine have been described, but there are few studies focusing on Modic changes in the cervical spine OBJECTIVE: To report on the prevalence, types, distribution of Modic changes and its relationship with cervical degeneration found in the cervical spine. METHODS: From 1 187 cases in the year 2009, 200 patients aged 20-83 years, randomly selected cervical spine MRI and X-ray were viewed. Data were recorded for patient age, patient sex, and the presence or absence of Modic changes, then the specific Modic type and the precise vertebral levels and location of these changes were recorded. The prevalence of Modic changes on sex, age, segment, grade of intervertebral disc degeneration, disc height and cervical curve was analyzed retrospectively. RESULTS AND CONCLUSION: Among 1 200 intervertebral discs of 200 patients, 23 (11.5%) patients with 29 (2.4%) intervertebral discs were involved with Modic changes. Eight (4%) cases with 10 (0.8%) discs were diagnosed as type Ⅰ; 13 (6.5%) cases with 16 (1.3%) discs were type Ⅱ; 2 (1%) cases with 3 (0.25%) discs were type Ⅲ. According to the segment, the lesions involved C2/3 for 0 (0%), C3/4 for 4 (0.33%), C4/5 for 6 (0.5%), C5/6 for 12 (1%), C6/7 for 7 (0.58%), C7/T1 for 0 (0%). These findings demonstrated that Modic changes are observed in the cervical spine, with the C5/6 level being the most commonly involved. Like in the lumbar spine in which Modic type Ⅱ changes predominate, type Ⅱ is the most, type Ⅲ is the least. They are far more common in the posterior area of the endplate. Modic changes are distributed mainly over the age of 50, which are correlated with ages, grade of disc degeneration, disc level, disc height and cervical curve. Related Articles | Metrics

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Analysis of risk factors for infection after total knee arthroplasty Xu Jie, Ma Ruo-fan, Ding Yue, Prakash-Raj Bhandari○, Li Wei-ping, Yang Rui 2011, 15 (13):  2450-2453.  doi: 10.3969/j.issn.1673-8225.2011.13.040 Abstract ( 340 )   PDF (494KB) ( 676 )   Save BACKGROUND: Infection is one of the most serious complications after total knee arthroplasty (TKA). But few studies focus on the risk factors related to infection. OBJECTIVE: To analyze the clinical risk factors for infection after TKA. METHODS: Among 122 patients who underwent TKA, 25 were male and 97 were female, with an average age of 63.1 years (range, 27 to 82 years). All the cases were followed up for 3.6 years averagely. Clinical factors were examined to analyze their influences on infection after surgery, including sex, age, obesity degree, joint primary disease (immunity-related disease), diabetes mellitus/hypertension, tumor, history of steroid drugs into article, type of prosthesis, bleeding during operation, operative time, postoperative drainage, duration of fever (> 38 °C), and haematin at 1 day postoperation. RESULTS AND CONCLUSION: There were 9 patients who developed infection after TKA. The incidence of infection in all patients was 7.4%. Logistic regression analysis demonstrated a definite association of surgical duration, volume of drainage and duration of fever after operation. The three factors increased the risk of infection with 5.823, 10.561, 7.757 times respectively (P < 0.05). Surgical duration, volume of drainage and duration of fever after operation are risk factors for infection after TKA. Related Articles | Metrics

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Locking compression plate with minimally invasion percuteoneous plate osteosynthesis for 32 patients with diaphyseal and distal tibial fracture Li Guo-sheng, Hu Yong-cheng 2011, 15 (13):  2454-2457.  doi: 10.3969/j.issn.1673-8225.2011.13.041 Abstract ( 277 )   PDF (475KB) ( 719 )   Save BACKGROUND: To ensure anatomical reduction, traditional plate internal fixation strips extensive periosteum to expose the fracture during treatment of distal tibial fracture, resulting in adverse effects, such as infection, wound, infection and delayed bone healing. OBJECTIVE: To evaluate the clinical effects of locking compression plate with minimally invasion percutaneous plate osteosynthesis on diaphyseal and distal tibial fracture. METHODS: A total of 32 patients with diaphyseal and distal tibial fracture were selected, including 26 males and 6 females, aged 18-76 years. They were treated with locking compression plate with minimally invasion percuteoneous plate osteosynthesis through closed reduction and minimal incision approach. After the operation, the patients were followed-up and examined by X-ray. The treatment effects were evaluated using Johner-Wruhs score assessment. RESULTS AND CONCLUSION: The 30 patients were followed up for 16 months. The fracture was healed, for an average healing time of 14 weeks. Two patients developed incision infection, 4 presented skin stimulation symptoms, 1 had screw breakage (Breakage was not detected by preoperative X-ray), 1 plate breakage, and 1 had superficial peroneal nerve injury. Johner-Wruhs score was excellent in 22 cases, good in 6, and fair in 2. The total excellent to good rate was 93%. Results show that locking compression plate with minimally invasion percuteoneous plate osteosynthesis in treatment of diaphyseal and distal tibial fracture leads to limited invasion, reliable fixation, low rate of complication, high rate of union, and well matches biological fixation principles. Related Articles | Metrics

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Dual plating through two separate incisions for repair of complicated tibial plateau fractures: Six-year follow-up of 17 cases in an institute Li Jian, Jiang Lin, Zhou Zhong, Deng Bi-quan 2011, 15 (13):  2458-2462.  doi: 10.3969/j.issn.1673-8225.2011.13.042 Abstract ( 310 )   PDF (602KB) ( 782 )   Save BACKGROUND: When using single plate for treating complicated tibial plateau fractures, it can only provide one-end stability of tibial plateau, result in eccentrically braced frames and prone to angular deformity. On the other hand, using lateral branch plate but neglecting cortical bone integrity easily leads to knee joint internal inversion. Dual plating through two separate incisions can increase the strength of fixation, prevent lateral condyle collapse and avoid deformity of internal and external inversion after operation. OBJECTIVE: To evaluate the clinical effects of treatment of complicated tibial plateau fractures with dual plating through two separate incisions. METHODS: A total of 17 patients with complicated tibial plateau fractures were selected from Department of Orthopaedics, Central Hospital of Wuhan between February 2004 and May 2010. There were 11 males and 6 females, aged 19-54 years and mean age of 33.6 years; left knee in 9 cases, right knee in 8 cases. According to AO classification: type B in 5 cases, type C in 12 cases; according to Schatzker classification: type Ⅳ in 3 cases, type Ⅴ in 9 cases and type Ⅵ in 5 cases. Surgical treatment with dual plating was implemented when edema and soft tissue reaction subsided at 6-10 days after injury happened. All cases were received reduction and bone graft on operation, moreover exercises with CPM machine and non-weight-bearing walking with crutches to recover the function of knee joint went on gradually from the first day after operation. RESULTS AND CONCLUSION: All patients were followed up for 8-72 months, an average of 25.9 months. Knee stiffness appeared in 1 case of old fractures of the tibial plateau after operation. Postoperative wound infection appeared in 1 case of open fractures was healed after treatment. Finally smooth articular surface of knee and normal limb lines appeared in all other cases. According to Merchant evaluation system, the knee function was excellent in 9 cases, good in 6 cases, fair in 1 case and poor in 1 case. The excellent and good rate was 88.2%. No material related adverse effect happened, which showed that dual plates have good biocompatibility. Related Articles | Metrics

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Changes of temporomandibular joint space following treatment with buccal multiloop removable appliance Wang A-na, Hou Lu, Sui Chang-de 2011, 15 (13):  2463-2466.  doi: 10.3969/j.issn.1673-8225.2011.13.043 Abstract ( 290 )   PDF (613KB) ( 565 )   Save BACKGROUND: The buccal multiloop removable appliance designed by Hou et al is new-type appliance for class Ⅲ malocclusion. OBJECTIVE: To investigate the cephalometry analysis of temporomandibular joint (TMJ) space changes before and after the treatment with a buccal multiloop removable appliance in the early stage of class Ⅲ malocclusion. METHODS: Twenty early stage of class Ⅲ malocclusion cases, including 7 males and 13 females, aged 5-13 years, 8.5 years in average, were chosen and the cephalometric analysis was performed. X-ray pictures were done to explain the changes in TMJ space before and after treatment. RESULTS AND CONCLUSION: The left and right linear percentages were changed before and after treatment, respectively. The left and right N/M was changed before and after treatment, respectively. Meanwhile, A and P changes could be achieved in combined treated group. All the findings indicated that the modified fixed the buccal multiloop removable appliance can lead to the reconstruction of TMJ. Meanwhile, suitable continuous orthodontic force does not lead to temporomandibular disorders. Related Articles | Metrics

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Application of computer system based on artificial neural network and artificial intelligence in diagnosing child mental health disorders Chen Bing-mei, Fan Xiao-ping, Zhou Zhi-ming, Li Xue-rong 2011, 15 (13):  2467-2470.  doi: 10.3969/j.issn.1673-8225.2011.13.044 Abstract ( 530 )   PDF (521KB) ( 690 )   Save BACKGROUND: It is not a report concerning utilization of artificial intelligence combined with artificial neural network in mental health domain, rather than that combining artificial intelligence, artificial neural network and simulating human brain thinking mode for diagnosing child mental health disorders. OBJECTIVE: Using computer to simulate thinking modes of human brain, to establish an artificial intelligence expert system for diagnosis and treatment of child mental health disorders based on artificial neural network and expert system. METHODS: The expert system involves in child psychiatry, child psychology, psychological measurement, psychological therapy, and computer science, and so on. The diagnosis system combines the diagnosis standard of ICD 10, DSM IV, CCMD-2, the epidemiological data, and the clinical data with senior psychiatrist knowledge. The clinical data were obtained from 14 epidemiological and outpatient department, and 1 125 valid data were harvested for the system compilation. RESULTS AND CONCLUSION: The system can diagnose 61 kinds of child mental health disorders. It includes more than 95% child mental health disorders. After diagnosis, the computer will give a treatment suggestion. Comparing the diagnosis by computer with diagnosis by the senior child psychiatrists, the consistent rate is 99%. The research can help the younger doctors to learn abundant clinical experiences of senior child psychiatrists and can help children of mental health disorders throughout the country. Related Articles | Metrics