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23 July 2010, Volume 14 Issue 30 Previous Issue    Next Issue

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Construction of a pelvic finite element model of Crowe Ⅳ developmental dislocation of the hip Liu Gui-qi, Zhou Yong-gang 2010, 14 (30):  5511-5514.  doi: 10.3969/j.issn.1673-8225.2010.30.001 Abstract ( 121 )   PDF (590KB) ( 473 )   Save BACKGROUND: Skeletal biomechanics digital finite element analysis can reduce experimental cost with finite element model as virtual sample, which can be used repetitively.  OBJECTIVE: To explore a method of building three-dimensional finite element model of pelvis with 3D finite element software, and analyze the stress around pseudo-acetabulum of developmental dislocation of hip (DDH) using the model. METHODS: Using DDH patient’s pelvic CT data, pelvic 3D object was reconstructed in the software of Mimics 10.0, and the surface was meshed. In Ansys10.0, the body meshing was performed, and the files were imported to Mimics10.0, which gave the material properties. The pelvic finite element model of DDH was established. In Ansys10.0, single limb standing was simulated, and static load was applied on the pseudo-acetabulum articular surface. The preliminary analysis of the model was made. RESULTS AND CONCLUSION: Based on DICOM format CT data, a semi-pelvic three-dimensional finite element model was established which included a true acetabulum and a pseudo-acetabulum. The model included 147 167 nodes and 113 898 elements. The pseudo-acetabular was close to sacroiliac joint. In single limb standing, pelvic stress concentrated in the bone between pseudo-acetabulum and the sacroiliac joints. Software of Mimics and Ansys provides a simple and effective method of 3D finite element modeling. This 3D finite element modeling method is also applicable to other bones. This finite elements method can effectively simulate the human bone stress under physiological and pathological conditions, and provide clinical reference and guidance. Related Articles | Metrics

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Construction and validation of a finite element knee joint model of major ligaments at different flexion angles Zhong Yan-lin, Wang Hai-peng, Rong Ke, Wang You, Xie Le 2010, 14 (30):  5515-5518.  doi: 10.3969/j.issn.1673-8225.2010.30.002 Abstract ( 166 )   PDF (434KB) ( 461 )   Save BACKGROUND: With development of computer technique and finite element theory, finite element model of main knee joint ligament has been used for biomechanical studies. The establishment of accurate and effective models of knee joint under different flexion degrees has become a focus. OBJECTIVE: To explore the way to construct and validate the finite element model of the major ligaments around knee at different flexion angles. METHODS: The knee joint specimen was dissected, and the peripheral soft tissues were removed to expose the major ligaments. The ligaments were wrapped with steel wire and scanned with CT scanner at different flexion angles. The insertion site was marked after removing all the ligaments by punching holes in the bones and scan again. The image data were input into the software MIMICS for three-dimensional reconstruction. The model was input into finite element software ANSYS after modification and adjustment, and the three-dimension finite element model was generated by setting the material property and dividing the body grid. 134 N anterior load was applied on the tibia to the model at full flexion angles in the software. The data of tibial anterior movement were collected, and the stress distribution was observed to validate the model. RESULTS AND CONCLUSION: The established model contained the elements of femur, tibia, anterior-posterior cruciate ligament and medial-lateral collateral ligament, and the model was validated by comparing with those of the other scientists and clinical experience. The model has good figure and function simulation, which can simulate knee movements at different flexion angles and can be used in further biomechanical study. Related Articles | Metrics

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Measurement and characteristic analysis of proximal tibia area parameters in normal Chinese populations  Zhang Bo, Pan Jiang, Lin Yuan, Zhang Xiao-dong, Wang Zhi-wei, Qu Tie-bing 2010, 14 (30):  5519-5522.  doi: 10.3969/j.issn.1673-8225.2010.30.003 Abstract ( 121 )   PDF (394KB) ( 560 )   Save BACKGROUND: Whether the shape and dimension of the total knee arthroplasty prosthesis are matched to the knee joint significantly affect the operation and postoperative effect. There are few researches of the Chinese proximal tibia parameters, so it is necessary to explore the characteristic data and domestic prosthesis. OBJECTIVE: To obtain the normal area parameters on the different resection levels of normal proximal tibia in Chinese. METHODS: A total of 82 normal Chinese (135 knees), including 85 knees in males and 50 knees in females, with an average age of 47.2 years (range from 19 to 82 years), were divided into groups according to the age, side of the knee and gender. Original CT image data were utilized to set up the three-dimensional model of Chinese normal knees and measure the related area parameters of proximal tibia section on the work station. RESULTS AND CONCLUSION: The average area of the proximal tibia section was (3 232.33±405.19) mm2. Statistics analysis showed that the area parameters of males were significantly greater than the females (P < 0.01), while there was no significant differences in area among different side, age, resection bone height and inclination angel (P > 0.05). The sex differences should be considered when designing the domestic tibial plateau prosthesis and total knee arthroplasty. The study obtained primary normal reference values of geometry of proximal tibia in Chinese, which provides evidence for clinical operation of tibial plateau prosthesis design and total knee arthroplasty. Related Articles | Metrics

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Adaptive variation of the space of intervertebral foramina under anteflexion and posterior extension conditions: Bryan cervical disc prosthesis replacement versus cervical plate combined with graft internal fixation Chen Shu-wen, Yin Chao-xin, Yan Ai-min, Liu Wen-he 2010, 14 (30):  5523-5526.  doi: 10.3969/j.issn.1673-8225.2010.30.004 Abstract ( 101 )   PDF (426KB) ( 314 )   Save BACKGROUND: Many reports have shown different experiment results about the biomechanical test effects of the stress on the adjacent segments of vertebra with interbody fusion. The experiment results are very different of the stress characteristic on the adjacent segments of vertebra with interbody fusion under the conditions of loading control and shifting control test mode. OBJECTIVE: To analyze adaptive variation of the space of intervertebral foramina C5/6 basing on graded-loading-force under forward flexion and rearward extended conditions under different conditions of intact cervical disc, cervical intervertebral discectomy, Bryan cervical disc prosthesis replacement, or anterior cervical discectomy and fusion using bone graft and plate fixation. METHODS: The pathologic variational regulation of the space of bone intervertebral foramina C5/6 had been analyzed under different graded-loading-force (0.25, 0.50, 0.75, 1.00, 1.25 and 1.50 N•m) in forward flexion and rearward extended under different conditions of intact cervical disc, cervical intervertebral discectomy, Bryan cervical disc prosthesis replacement, or anterior cervical discectomy and fusion using bone graft and plate fixation. RESULTS AND CONCLUSION: Under the different conditions of graded-loading-force in forward flexion and rearward extended conditions, on adult’s corpse cervical spine samples, the length diameter, superior width, inferior width and space of bone intervertebral foramina of C5/6 of the cervical intervertebral discectomy group was lower than that of the other groups (P < 0.05), the Bryan cervical disc prosthesis replacement group was higher than cervical intervertebral discectomy group (P < 0.05). The experiment results have shown that the average area data of space of bone intervertebral foramina C5/6 decreases after cervical intervertebral discectomy. Related Articles | Metrics

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Tibial tunnel angle and bone implant designs: Arthroscopic posterior cruciate ligament tibial inlay reconstruction technique  Jiang Xue-feng, Yang Hui-guang, Zhang Yun-qing, Xu Jun, Huang Guo-wei, Ren Ya-jun, Sun Hui-qing 2010, 14 (30):  5527-5530.  doi: 10.3969/j.issn.1673-8225.2010.30.005 Abstract ( 86 )   PDF (461KB) ( 365 )   Save Related Articles | Metrics

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Analysis of static force and fatigue between thread structure of dental implant and contact surface Gao Fei, Zhang En-wei, Wei Shi-cheng, Fang Jing 2010, 14 (30):  5531-5534.  doi: 10.3969/j.issn.1673-8225.2010.30.006 Abstract ( 221 )   PDF (508KB) ( 609 )   Save BACKGROUND: Many factors affluence the stability of dental implant, the implant-bone interface, implant-abutment interface, as well as the thread structure of implant, play a key role in long term reliability. OBJECTIVE: To analyze static force and fatigue between thread structure of dental implant and contact surface, and to explore the potentially fatigue fracture of dental implant. METHODS: A three-dimensional model of dental implant and alveolar bone were established by using CAD software CATIA and Ansys Workbench, respectively. Then the static force and fatigue between dental implant and alveolar bone were analyzed after meshing the model, defining attribute, connections, and loading. RESULTS: A two-segment abutment implant system was constructed using CAD software CATIA. The implant system was characterized by platform transfer, hexagonal location, and taper seal, which represented structure of implants. The size of implant system was designed according to actual sizes and the assemblage was based on standard of mechanical design.    Stress concentrated in screw and interface of dental implant and fatigue safety factor of the region was lower. These are potentially fatigue fracture of dental implant. Related Articles | Metrics

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Medial-dimension measurement of the femoral neck for preoperative selection of femoral component  Li Yi-zhong, Li Jian-long, Lin Jin-kuang, Yao Xue-dong, Zhuang Hua-feng, Jiang Zhi-zhao 2010, 14 (30):  5535-5538.  doi: 10.3969/j.issn.1673-8225.2010.30.007 Abstract ( 78 )   PDF (379KB) ( 513 )   Save BACKGROUND: A good press-fit between the femoral component and the cross-section of medullary cavity of proximal femur is very important. The accuracy of preoperative templating of noncemented femoral prostheses is low. It is necessary to search a new method for preoperative prediction of total hip arthroplasty (THA). OBJECTIVE: To analyze the application of preoperative medial-dimension measurement method of femoral neck to predict the size of suitable femoral prosthesis in THA. METHODS: Clinical data of 58 patients (65 hips) undergoing primary total hip arthroplasty were collected. Prediction to select femoral stem was based on the medial dimension of medullary cavity of femoral neck accurately measured from preoperative CT film. Conventional preoperative templating served as control. RESULTS AND CONCLUSION: The medial dimension of medullary cavity of femoral neck was correlated fairly well with sizes of the stems (r=0.84-0.85, P < 0.05), suggesting that the application of the medial dimension of medullary cavity of femoral neck was feasible for prediction of femoral component in THA. The excellent rate of predicted femoral stem and the excellent and good rate in the medial-dimension measurement method of femoral neck were greater than the preoperative templating (P < 0.01, P < 0.05). Particularly, the excellent rate of medial-dimension measurement method of femoral neck was 66% in the group more than 45 years of age, greater than the preoperative templating method (32%, P=0). As a measurement to predict the appropriate femoral implant in total hip arthroplasty, the medial-dimension measurement method of femoral neck has better accuracy than the conventional preoperative templating, particularly for the elderly. Related Articles | Metrics

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Mid-term effect of total hip replacement with a tapered femoral component for elderly patients Liu Hong-ming, Sun Jun-ying, Yang Li-wen, Zeng Jin-cai, Luo Yuan, Yang Mao-wei, Li Yong-wang 2010, 14 (30):  5539-5542.  doi: 10.3969/j.issn.1673-8225.2010.30.008 Abstract ( 112 )   PDF (381KB) ( 545 )   Save BACKGROUND: Increasing elderly patients with hip arthropathy require total hip replacement. However, it remains controversial on fixation type and ideal femoral shaft design due to bone mass loss and poor healing. OBJECTIVE: To observe the mid-term effect of total hip replacement with a tapered femoral component for elderly patients. METHODS: From February 2002 to February 2004, 65 cases (70 hips) underwent uncement total hip replacement with a tapered F2L femoral component in Department of Orthopedics, First Hospital Affiliated to Soochow University. The diagnosis included femoral neck fractures in 35 cases, osteoarthritis in 10 cases, avascular necrosis of the femoral head in 8 cases, loosening of artificial femoral head in 9 cases, rheumatoid arthritis in 2 cases, and arthrodesis in 1 case. Clinical and radiographic evaluations were performed at postoperatively 1 week, 3 and 6 months. The patients were followed up every year thereafter to recheck hip function by Harris score and X-ray. RESULTS AND CONCLUSION: Six patients died of cancer and four died of Cardio-cerebral vascular diseases．The remaining 55 cases (60 hips) were followed up for 6-7 years, with an average follow-up of 6.5 years．At the latest follow-up, the mean Harris hip score was 90 points (85-95 scores); 2 patients (3.3%) reported mild thigh pain, but no case required revision. By the measurement of the X-ray, 36 stems had less than 1.5 mm of subsidence within the l year follow up. The remainer stems had no subsidence. Radiographic evaluation demonstrated all stems to get bone ingrowths fixation with evidence of spot welds, cancellous condensation and cortical hypertrophy visible around Gruen zone 6 at 3 to 6 months postoperatively, including patients of Dorr type C．Reactive 1ines covered the noncoated zone of the femoral stems for some cases. No hip had extensive proximal end osteolysis or distal intramedullary osteolysis and loosening. The patients who used tapered femoral stems which were placed in the marrow obtained the initial stability because of the design features, but also obtained the quadratic stability because walking and weight-bearing could lead to a modest subsidence of the prosthesis. Therefore, it is helpful to improve mid-term clinical results of the cementless total hip replacement for elderly patients Related Articles | Metrics

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Effects of modified versus conventional training methods for high-flexion knee replacement  Li Dai-ying, Zhang Wei-wei, Tang Xian-wen 2010, 14 (30):  5543-5546.  doi: 10.3969/j.issn.1673-8225.2010.30.009 Abstract ( 138 )   PDF (453KB) ( 387 )   Save BACKGROUND: A better range of motion following application of high flexion knee prosthesis replacement surgery is highly correlated with preoperative joint activities degree and postoperative rehabilitation exercise. OBJECTIVE: To explore the clinical effect of improved training methods of high-flexion prosthesis and compare with traditional functional exercise. METHODS: The 90 cases undergoing high-degree flexion knee prosthesis replacement were randomly divided into observation and control groups. The control group was subjected to routine functional exercises following replacement. The observation group was subjected to analgesic drugs and replacement of muscle relaxants, and progressive modified functional exercise including knee and ankle flexion and extension， knee flexion exercises such as squatting. The clinical effect was evaluated using HSS and range of motion (ROM) in knee joint function. RESULTS AND CONCLUSION: The improvement of knee score and knee joint activity was significantly better in the observation group than the control group at different time points after replacement (P all < 0.001). Results show that functional exercise should be performed early following joint replacement, and improved training method improves the range of motion and function of joint following high-flexion prosthesis replacement. Related Articles | Metrics

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Femoral neck preservation in total hip replacement in 42 cases: A more than 12-month follow-up in the same institute within 5 years  Lin Ji 2010, 14 (30):  5547-5550.  doi: 10.3969/j.issn.1673-8225.2010.30.010 Abstract ( 120 )   PDF (449KB) ( 364 )   Save BACKGROUND: Femoral neck is resected in total hip replacement, which can change the force balance between pressure system and tensile stress system. Femoral neck preservation can maintain natural bone structure of femoral neck, keep the stress distributing along proximal end of femoral neck, and prevent prosthesis loosening result from osteoporosis at the proximal end of femoral neck. OBJECTIVE: To evaluate the effect of femoral neck preservation on total hip replacement. METHODS: Femoral neck preservation in total hip replacement was performed on 42 cases (52 hips) from March 2003 to April 2008. S-ROM prosthesis (Acetabular and femur part) was used in the operation. The operation duration, blood loss, average postoperative hospitalization, Harris scores and perioperative complications were observed. X-ray film was performed after replacement. The abduction angle and anteversion angle of the acetabular prosthesis was measured. RESULTS AND CONCLUSION: All the cases were followed up for 12-61 months with the average of 39 months. The operation duration was 30-70 minutes with the average of 45 minutes, and the blood loss was 70-200 mL with the average of 110 mL. Postoperative X-ray film showed that the abduction angle was 44.1° and the anteversion angle was 21°. All the patients were ambulatory 5 days after surgery with the help of walker. The preoperative Harris hip score was (32.7±6.3), which was (93.2±4.1) at 3 months after operation. Total hip replacement with preservation of femoral neck has the advantages of minimal invasion, less blood loss, good biodynamic harmony, excellent stability of the prosthetic hip, and less prosthesis wear. It can replace traditional total hip arthroplasty as a new option. Related Articles | Metrics

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Endoprosthetic proximal femoral replacement for 37 patients with proximal femoral metastatic tumor in one institute: Retrospective analysis within one year Chen Kai, Liang Wen-qing, Cai Zheng-dong 2010, 14 (30):  5551-5554.  doi: 10.3969/j.issn.1673-8225.2010.30.011 Abstract ( 155 )   PDF (430KB) ( 347 )   Save BACKGROUND: Artificial joint prosthesis reconstruction is independent to bone healing, but can restore joint function, relieve pain and rebuilt joint stability. For metastatic tumor proximal to femur, artificial joint prosthesis reconstruction is the best surgical treatment. OBJECTIVE: To discuss the clinical outcome with endoprosthetic proximal femoral replacement for the patients with metastatic bone disease. METHODS: A total of 37 cases of metastatic tumor in the proximal femur were treated by wide excision and endoprosthetic proximal femoral replacement, including 20 patients undergoing endoprosthetic reconstruction for pathologic fractures, and others for impending fractures indicated by complains of pain and problems with walking. RESULTS AND CONCLUSION: The survival time was 2 weeks to 9 years with an average time of 11 months. A total of 32 patients survived for 2-month postoperatively, of them, 14 patients survived for 1 postoperative year. The MSTS function score was 21.68 at the first postoperative year. A total of 8 patients survived after 2 years postoperatively. Of 37 patients, 1 developed deep infection, 2 femoral prosthesis loosening, 1 prosthesis dislocation, 2 abnormal walking due to incomplete abductor strength, 2 limb crispation deformity, and 1 heterotopic ossification. In patients with metastatic disease in the proximal femur, endoprosthetic reconstruction can provide early and stable fixation, remove metastasis with pain reduction and good functional results. Related Articles | Metrics

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Total hip replacement for 9 patients with valgus knee deformity  Jia Xiao-min, Wang Jun-feng, Shi Nan-zheng, Ma Dong-ping 2010, 14 (30):  5555-5558.  doi: 10.3969/j.issn.1673-8225.2010.30.012 Abstract ( 143 )   PDF (361KB) ( 373 )   Save BACKGROUND: Artificial joint replacement can relieve pain, correct deformity and improve life quality of patients with severe joint disease. OBJECTIVE: To investigate the methods and clinical results of total knee replacement in patients with valgus knee deformity． METHODS: A total of 9 cases (9 knees) of valgus knee, aged 50-75 years, were treated with selected. X-ray before operation showed average 12.9° valgus (ranging from 10° to 37 °). Medial parapatellar approach was adopted, and standard osteotomy and only lateral softtissue release were performed, following by total knee replacement. Clinical and radiographic evaluations including range of motion (ROM) and Knee Society Score System (KSS) were performed during follow-up. RESULTS AND CONCLUSION: The valgus angle was reduced from 12.9° to 4.3° after replacement, and range of motion was improved from 75° to 105°. The average HSS scores increased from preoperative 31.17 to postoperative 87.83. All changes were significantly different (P < 0.01). All valgus was corrected basically. All of the cases had no pains after operation, and the function of knees were apparently improved. The techniques of medial parapatellar approach, standard osteotomy and only lateral soft tissue release can correct a fixed valgus deformity successfully in patients undergoing primary total knee replacement, and preliminarily provides excellent results. The follow-up is necessary for further long-term outcome. Related Articles | Metrics

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Anterior open door decompression of cervical vertebral canal using CT three-dimensional reconstruction and anatomic study: Design and feasibility Zhang Qing-jun, Hu Yu-hua, Qian Jin-yong, Wang Chang-feng, Pang Liang 2010, 14 (30):  5559-5563.  doi: 10.3969/j.issn.1673-8225.2010.30.013 Abstract ( 129 )   PDF (510KB) ( 317 )   Save BACKGROUND: Spinal cord compression from the front of the heavy, oppressive, a long segment of cervical disease, before the direct lateral approach to the spinal cord decompression, the exact effect of surgery, but surgery risks are great, difficult and posterior approach is commonly used in clinic. Few reports have addressed anterior open door expansive laminoplasty of cervical vertebrae. OBJECTIVE: To design the method of anterior open door decompression of cervical vertebrae and to explore anatomical basis of the procedure. METHODS: Totally 100 vertebrae of 20 dried human cervical spines between the C3 and C7 were measured with caliper to get the following parameter: distance between the tip of uncinate process (UP) and medial wall of transverse foramina, interuncinate process distance, sagittal diameter of vertebral body. Three formalin preserved human cadaveric cervical spines were chosen for simulated operation and observed by the seneation10 CT scan (Siemens, Germany) respectively. The vertebral bodies were partially removed until posterior wall of the vertebral body was fully exposed. The posterior wall surrounding the ossification was removed at three sides. Then the posterior wall of cervical vertebrae was grooved slowly and separated from the underlying spinal dura mater with the assistance of the lift-hook designed by ourselves and the posterior wall and posterior longitudinal ligament were removed. The posterior wall was fixed with suture silk on unoperated side of the vertebrae if it was adhered with posterior longitudinal ligament too serious to separate. RESULTS AND CONCLUSION: The simulated operation on cadaveric spines was performed successfully and bone window decompression was shown well on spiral CT scan. Distance between the tip of UP and transverse foramina, interuncinate process distance and sagittal diameter of vertebral body increased gradually at each segmental level between C3 and C7. The data were (3.0±0.2) to (3.9±0.5) mm, (20.2±1.9) to (26.3±1.7) mm and (14.2±1.3) to (17.4±1.9) mm respectively. Results have suggested that anterior-lateral hemiexpansive open door decompression of cervical vertebrae is a safe, feasible and effective treatment for serious compression from the front of cervical spinal cord such as ossification of posterior longitudinal ligament, hyperosteogeny and ossification of intervertebral disc. Related Articles | Metrics

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MRI measurement and clinical value of nervous tissues surrounding the cervical vertebral pedicle Zhou Shan 2010, 14 (30):  5564-5567.  doi: 10.3969/j.issn.1673-8225.2010.30.014 Abstract ( 112 )   PDF (368KB) ( 337 )   Save BACKGROUND: In internal fixation methods of the cervical vertebrae, the stability of vertebral pedicle fixation was strongest. The vertebral pedicle is surrounded by vertebral artery, spinal cord, dural sac and nerve. Damages to above-described tissues are dangerous or fateful. Thus, the application and generalization of vertebral pedicle screw fixation techniques are limited. Magnetic resonance imaging (MRI) has high resolution of soft tissue, and can be used as a beneficial method for studying nervous tissues surrounding cervical vertebral pedicle. OBJECTIVE: To evaluate clinical significances in transpedicular screw fixation with MRI measurement of cervical vertebral pedicle adjacent neural structure. METHODS: The cervical segment of 62 health adult examples had been scanned by MRI. The measurement indexes included 7 items: the radius vector of vertebral canal, the transverse diameter of vertebral canal, the exponent of vertebral foramen, radius vector of spinal cord, the transverse diameter of spinal cord, the distance of pedicle to superior nerve root, and the distance of pedicle to inferior nerve root. RESULTS AND CONCLUSION: Radius vector of vertebral canal decreased fast from C1 to C4 and increased slowly from C3 to C7. From C1 to C2, transverse diameter of vertebral canal significantly decreased, whereas from C3 to C7, it increased slowly. Transverse diameter of vertebral canal of C1 was biggest, but that of C2 was smallest. Radius vector of spinal cord and transverse diameter of spinal cord had a clear increase in C5 and C6. The distance of pedicle to superior nerve root was smaller than the distance of pedicle to inferior nerve root. These indicated that MRI can reveal the imaging features of cervical pedicle adjacent neural structure clearly and provide radiology data for transpedicular screw fixation. Related Articles | Metrics

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Visual image processing strategy based on sparsity and synchronization in the visual cortex prosthesis Shi Li, Liu Xu-hui, Zhong Li-hui 2010, 14 (30):  5568-5572.  doi: 10.3969/j.issn.1673-8225.2010.30.015 Abstract ( 109 )   PDF (605KB) ( 312 )   Save BACKGROUND: Visual system is the effective and important sensory system for animals receiving outside information. The number of the blind patients who are caused by the visual diseases or visual injury is boosting, and the visual cortex prosthesis is a promising way for the patients to re-achieve the vision. Despite some progresses after several years research of the visual cortex prosthesis, there remain issues and challenges in visual cortex prosthesis. OBJECTIVE: Because the number of the microelectrode which is implanted in the visual cortex is restricted, the visual image processing strategy based on sparsity and synchronization in the visual cortex prosthesis is proposed. METHODS: The strategy was based on the physiological properties of the visual cortex. Firstly, the image basic functions were abstracted using the sparsity of the Topographic Independent Component Analysis (TICA). Then, the optimal responses of basic functions were selected using pulse-coupled neural networks (PCNN). Finally, the optimal responses were used to stimulate the corresponding neurons to restore the visual image. RESULTS AND CONCLUSION: Simulated results demonstrated that the nature images were representative using less available neurons. Therefore, it could lessen number of the electrodes of the visual cortex prosthesis which were implanted in visual cortex for the blind people. Related Articles | Metrics

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Simulation and optimization of functional CT imaging based on bolus injection of contrast medium    Wang Sheng-yi, Qian Ying 2010, 14 (30):  5573-5576.  doi: 10.3969/j.issn.1673-8225.2010.30.016 Abstract ( 197 )   PDF (484KB) ( 452 )   Save BACKGROUND: Functional CT technology allows morphological and functional imaging simultaneous on the same stage by the traditional CT device. OBJECTIVE: To search a reasonable clinical method to optimize CT imaging using contrast agent bolus injection method. METHODS: Using computer simulation technology, simulation experiment was performed using clinical CT image data from the hospital functions to study the contrast agent bolus injection method (single pulse and multiple pulse bolus injection) and the relationship between functional imaging. The simulation results were subjected to statistical error analysis to identify the best method of clinically useful contrast agent bolus. RESULTS AND CONCLUSION: Pulse bolus injection of contrast medium was better to reduce the blood flow parameters and benefit capillary permeability surface parameters and mean transit time parameter uncertainty compared with a single bolus injection of contrast medium on the pulse. Multi-pulse group involves a two-pulse and three pulse bolus injection, in which the use of double pulse bolus injection improved the relative reference values, 36.9% blood parameters and 30% capillary surface permeability parameter respectively. Three-pulse group exhibited a certain degree of improvement in individual physiological parameters compared with double-pulse bolus injection, but the improvement is not particularly clear. Therefore, double pulse bolus injection can be used in clinical practice. Related Articles | Metrics

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Numeral critical fuse frequency determination Geng Yan, Hu Wen-dong, Ma Jin, Zhang Lei, Wang Tao, Han Wen-qiang 2010, 14 (30):  5577-5580.  doi: 10.3969/j.issn.1673-8225.2010.30.017 Abstract ( 118 )   PDF (426KB) ( 878 )   Save BACKGROUND: Critical fuse frequency (CFF) determination is influenced by subjective and motive factors. OBJECTIVE: To explore the relationship between the frequency and the reflect time and accuracy by the instruments of numeral critical fuse frequency (INCFF), and determine the CFF, compared with the instrument of shine flicker EP403.  METHODS: A total of 14 male students, aged 17-20 years, with normal vision, were selected. The reflect time and accuracy were determined by INCFF and shine flicker EP403, and their relationship was calculated. The correlation of frequency with reflect time and accuracy was analyzed. CFF was calculated by two methods and analyzed. RESULTS AND CONCLUSION: Negative relationship was between frequency and accuracy. The test-retest reliability of INCFF was 0.739 and P was 0.036; there was not different between INCFF and shine flicker EP403. INCFF displayed good practicability and reliability. Related Articles | Metrics

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Optimal design of intravascular stent arc-strut element structure based on biomechanical performance Lao Yong-hua, Zhi Xiao-xing, Lin Ze-feng, Li Xiao-nin, Cen Ren-jing, Huang Yue-shan 2010, 14 (30):  5581-5585.  doi: 10.3969/j.issn.1673-8225.2010.30.018 Abstract ( 118 )   PDF (474KB) ( 633 )   Save BACKGROUND: Support the expansion of blood vessels in the implanted process of requires stent structure with complex biomechanical properties. The structure can achieve optimal overall performance by integrated multi-objective optimization. OBJECTIVE: Based on designs of various intravascular stent structures, the features parameters were extracted for optimization analysis of biomechanics. METHODS: Based on the analysis of biomechanical behavior: metal-based coverage, the maximal stent stress of expansion, maximal stent radius of expansion, axial recoil rate, radial recoil rate, finite element analysis software ADINA was used to establish 81 stent structures of closed, parallel, and open-arc strut element with different circumstantial unit number, arc-strut width and axial length of the stent unit element; the non-dimensional method and multi-objective optimum ranking was used to analyze the stent biomechanical behavior. RESULTS AND CONCLUSION: Results showed that mixture structure of stent with closed, parallel, and open-arc strut element can be designed, and that the structure possesses mainly large axial length of the stent’s closed, parallel strut element and small arc-strut width uniformly. It is significantly important for the stent structural design and mechanical behavior evaluation system. Related Articles | Metrics

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Establishment of three dimensional finite element parameterization models of continuous post-and-core crown with diameter and length variation Gao Jian-yong, Wang Shao-hai, Zhu Qiang, Wang Dong-mei, Zheng Yuan-li 2010, 14 (30):  5586-5590.  doi: 10.3969/j.issn.1673-8225.2010.30.019 Abstract ( 114 )   PDF (526KB) ( 360 )   Save BACKGROUND: Univariate or integer analysis is used for analyzing diameter and length variation of continuous post-and-core crown due to the limitation of software and hardware technology. Many finite element models involved in this analysis, thus, the deviation exists between groups. OBJECTIVE: To construct three dimensional finite element models of continuous post-and-core crown with diameter and length variation. METHODS: Thin slice CT scanning technology was used in combination with Matlab software to identify tooth margin. Pro/E and Ansys software was utilized to rebuild three dimensional maxillary central incisor model based on the thin slice CT scanning images. The diameter of post and length of post were set as the input vadables in Ansys Workbench software. The diameter of post ranged from 1.0 to 4.1 mm, and length of post ranged from 3.0 to 8.0 mm. The models were meshed and analyzed in Ansys workbench 10.0 software automatically. RESULTS AND CONCLUSION: Establishment of three dimensional finite element models of continuous post-and-core crown of nickel-chromium alloy and carbon fiber with diameter and length variation. Continuous post diameter and length changing three dimensional finite element models can be rebuilt by bidirectionaI parameter transmit of Ansys workbench software and Pro/E software． Related Articles | Metrics

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Finite element analysis of the angulate abutment of non-imbedding implant in the anterior maxilla Chen Zu-xian, Wang Chao, Fan Yu-bo, Gu Xiao-ming, Han Jing-yun, Wang Li-jun 2010, 14 (30):  5591-5595.  doi: 10.3969/j.issn.1673-8225.2010.30.020 Abstract ( 106 )   PDF (518KB) ( 471 )   Save BACKGROUND: When the abutment angulations of the upper mandible increase to 25°, the implant stress increases 18%. When the stress increases exceed to the bearing range, the implant is failed. Therefore, greater abutment angulation is not helpful. It remains unclear the maximal angulation that cannot affect implantation success. OBJECTIVE: To investigate the stress distribution of peri-implant bone which is subjected to different loading conditions when the different abutment angulations are applied, and to analyse the safety factor of the different implants to determine the maximum angulation. METHODS: The finite element models of the different angulate abutments were established in commercial software packages, and stress distribution of both implant and peri-implant bone were compared. RESULTS AND CONCLUSION: With the increased abutment angulation, the larger maximum von-Mises stress was observed, and the position of the stress concentration diverted from top of implant to the neck of the implant (P < 0.05). The abutment < 25° is recommended to achieve higher survival rates of dental tooth treatments in the anterior maxilla. When the abutment has to be larger than 25°, it is better to decrease its loading. Related Articles | Metrics

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Mechanical design and motion control experiment of a finger rehabilitation robot  Yu Jing-jing, Qian Jin-wu, Shen Lin-yong, Zhang Ya-nan 2010, 14 (30):  5596-5600.  doi: 10.3969/j.issn.1673-8225.2010.30.021 Abstract ( 114 )   PDF (756KB) ( 490 )   Save BACKGROUND: Clinical application confirms that during the early rehabilitation and spontaneous recovery, continuous passive motion can compensate the insufficient active movement, increase physical activity and decrease the corresponding complications in the patients with postoperative limb or brain nerve injury. OBJECTIVE: To design a finger rehabilitation training robot based on normal human finger movement trajectory. METHODS: According to continuous passive motion rehabilitation theory, the rehabilitation training robot was designed. This robot mainly included four fingers mechanism and thumb mechanism, and achieved finger to finger movement using stepper motor. RESULTS AND CONLUTION: For the rehabilitation of fingers with different length, mechanical motion control experiment was performed. The average relative error between mechanism drive rod and expected data was about 2%. The results demonstrate that the feasibility of mechanical design and control method robot, and the finger rehabilitation training robot can accomplish finger rehabilitation well. Human finger rehabilitation training test will be conducted in future stage. Related Articles | Metrics

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Reconstruction of a three-dimensional solid model of Mini-SG® attachment in 3DMAX Dong Zheng-jie, Wang De-fang, Xu Kan, Bao Xiang-jun 2010, 14 (30):  5601-5604.  doi: 10.3969/j.issn.1673-8225.2010.30.022 Abstract ( 144 )   PDF (607KB) ( 504 )   Save BACKGROUND: Mini-SG ® attachment is a kind of extra-coronal precision attachment, which is characterized by strong retention, good stability, aesthetics and comfort, as well as protecting the abutment. However, it is difficult to make a precise three-dimensional (3-D) solid model though conventional CT due to its precise and tiny structure. Although the precision can reach 1 μm using Micro-CT, it encounters the huge workload, time-consuming and hard sledding, also with radiation damage from X-ray. OBJECTIVE: To reconstruct 3-D solid model of Mini-SG® attachment. METHODS: According to the actual exact size of Mini-SG® attachment positive components and negative components obtained from network and measurement with vernier caliper, the 3-D solid model of Mini-SG® attachment was reconstructed with 3DMAX software in computer. RESULTS AND CONCLUSION: The precise 3-D solid model of Mini-SG® attachment has been reconstructed according to existing or measurable precise data through the use of boolean calculation with 3DMAX software. Accordingly, an accurate 3D model of an oral prosthesis like attachment, implant as long as their accurate data can be acquired. Related Articles | Metrics

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Development of a pluggable multi-parameter monitor based on embedded system Chen Hai-jun, Jin Hao-yu, Liu Qian-cheng, Xu Bin-feng 2010, 14 (30):  5605-5608.  doi: 10.3969/j.issn.1673-8225.2010.30.023 Abstract ( 158 )   PDF (498KB) ( 569 )   Save BACKGROUND: With the invention and uses of parameter modules, common embedded monitor is not able to offer support to these newly-added parameter modules. Moreover, those advanced parameter modules are produced by foreign companies, which are very expensive. OBJECTIVE: To achieve monitor offer support to parameter modules of different combinations and to realize the share of parameter modules. METHODS: Pluggable multi-parameter monitor uses ARM9 as hardware base, embedded Linux as operating system, and MiniGUI as the program. We tried to separate physiological parameter modules from mainframe through reasonable design on software and hardware RESULTS AND CONCLUSION: This method realized the dynamic loading of parameter modules. This monitor exhibits advantages of small size, high reliability, and humanistic design of alternation. Every parameter module can plug and play immediately, and can work independently. Therefore, it has high practical value. Related Articles | Metrics

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Evaluation and risk factors of sub-health in Chinese population based on mathematical models Zhou Ya-fang, He Jian-tai, Zhang Yang-de, Liu Wei-dong, Sun Wei-jia, Zeng Qiang, Tan Jia-ju 2010, 14 (30):  5609-5613.  doi: 10.3969/j.issn.1673-8225.2010.30.024 Abstract ( 130 )   PDF (585KB) ( 737 )   Save BACKGROUND: Generally the sub-health samples gathered in the north and south areas were very rare, and the sub-health distinction lacks the standard. OBJECTIVE: To collect big samples through the multi-local multi-centers to establish the sub-health judgment mathematical model, so as to form the diagnostic criteria of sub-health, identify the important characteristics of sub-health status of populations and analyze the risk factors. METHODS: According to internationally recognized health measurement scale, quantitative evaluation questionnaire was established. A total of 2 097 cases from China's political center, economically developed regions, and central areas of three hospitals including the PLA General Hospital, Central South University of Xiangya Hospital, and the First People's Hospital of Foshan. Data were entered with strictly quality controlled method. Variables were selected with statistical methods. Logistic regression model and classification tree model were established to obtain the final regression equation and important characteristics. RESULTS AND CONCLUSION: China's proportion of the population in sub-health was 57.8% of surveyed samples, suggesting the common appearance of sub-health. The established logistic regression model was a good method of sub-health evaluation. The important clinical features of sub-health include the hands and feet tremble or chills, fever, shortness of breath, palpitation, constipation, sleep sweating, indigestion, loss of appetite, decreased energy, throat foreign bodies, legs heavy, attention, insomnia, and mind empty. Related Articles | Metrics

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Infrared thermography based 3D temperature field reconstruction of biological tissue heat transfer Ma Guo-jun, Jiang Guo-tai, Sun Bing 2010, 14 (30):  5614-5617.  doi: 10.3969/j.issn.1673-8225.2010.30.025 Abstract ( 243 )   PDF (478KB) ( 510 )   Save BACKGROUND: Infrared thermography as a new technology for non-contact temperature measurement has the advantage of non-invasive, fast and convenient. And computer can be used to reconstruct 3D inner temperature field of biological tissue. OBJECTIVE: For measurement and reconstruction of temperature field in tumor hyperthermia, to propose new methods of 3D temperature field reconstruction for biological tissue. METHODS: Infrared thermography technology was applied to measure 2D temperature distribution non-contactly of sliced-biomaterial, which based on bi-heat transfer and information of infrared thermal emitter. Temperature information was converted to gray images to be visualized, and pseudo-colorly processed. In addition, every pixel in infrared thermograph was allocated color and opacity by transfer function, so as to reconstruct temperature field of sliced-biomaterial by volume rendering ray casting algorithm. RESULTS AND CONCLUSION: Experiment results showed that, based on algorithm of infrared thermal emitter and information obtained from thermal infrared imager was converted to temperature and displayed as pseudo-color. And 3D temperature field obtained from sliced-biomaterial was reconstructed with ray casting. It provides new technology and method for measurement and observation of temperature field in hyperthermia. Related Articles | Metrics

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Substance P expression in lumbar facet joint capsule in degenerative lumbar disease patients Zuo Jin-bu, Li Jia-mou, Zhang Chun-bo, Lin Xin 2010, 14 (30):  5618-5621.  doi: 10.3969/j.issn.1673-8225.2010.30.026 Abstract ( 104 )   PDF (376KB) ( 497 )   Save BACKGROUND: Previous animal or corpse-based studies show that substance P is increased in degenerative lumbar facet joint bone below cartilage and calcified cartilage nerve fiber in lumbar facet joint-derived low back pain. OBJECTIVE: To investigate the substance P expression changes in facet joint capsule in patients with degenerative lumbar disease. METHODS: A total of 18 cases were selected by diagnostic block before operation in degenerative lumbar disease. The test group experienced resection of facet joint capsule, and the control group had no low back pain before fracture. Immunohistochemical method was used to observe the SP immunoreactive fibers in the degenerative facet joints capsule. RESULTS AND CONCLUSION: In the test group, substance P immunoreactive nerve fibers were observed in 15 cases, and 3 cases had no positive reaction. Substance P immunoreactive nerve fibers distributed in joint capsule and subchondral bone area, and most of them were located in facet capsule. The fibers were also detected in plical tissue of the capsule. They were not all associated with large blood vessels, but some of them ran freely in the stroma. In addition, a few substance P immunoreactive nerve fibers were observed in 5 cases of the control group, and 13 cases were negative. The degenerative change of facet joint capsule is one of the important causes of chronic low back pain. The observation provides morphological basis for low back pain, implying that the substance P immunoreactive fibers might involve in facet degeneration and might be an important source of the lower back pain. Related Articles | Metrics

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Interleukin 1 beta expression in Achilles tendon of stress-shielded rats following ultrasound treatment   Zhang Jing, Ma Yan-hong, Wang Wei, Yan Xiao-yan, Zhao Hua-kun 2010, 14 (30):  5622-5625.  doi: 10.3969/j.issn.1673-8225.2010.30.027 Abstract ( 123 )   PDF (584KB) ( 299 )   Save BACKGROUND: Ultrasound has been clinically used to treat acute and chronic soft tissue injury, but the ultrasonic treatment for tendon contracture has been rarely reported. OBJECTIVE: To observe the effect of ultrasonic treatment on level of interleukin 1β (IL-1β) in Achilles of stress-shielded rats． METHODS: Twenty-four SD rats were randomly divided into three groups: normal group, model group, and ultrasound treatment group. The left hind limbs of all rats of the later two groups were modeled using Achilles tendon cerclage combined with sciatic nerve cut method. At 3 weeks after surgical operation, the treatment group was subjected to ultrasound treatment, strength 1W/cm2, frequency 1MHz, inflation ratio 20%, 5 days per week, once per day, 10 minutes once, for a total of 3 weeks. At 6 weeks post-surgery, the left hind limb Achilles tendon tissue was detected by transmission electron microscopy and the level of IL-1β was detected by enzyme-labeled immunosorbent assay.  RESULTS AND CONCLUSION: After 3 weeks of ultrasound treatment, collagen fibers arranged neater than in the model, small fibers decreased, closed to the control group. The level of IL-1β in the model group was significantly higher than the normal group. After ultrasound treatment, the level of IL-1β was dramatically decreased. The results suggested that ultrasound treatment played an effective role in the treatment of Achilles tendon contracture, which might reduce the level of IL-1β in the Achilles tendon. Related Articles | Metrics

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Efficacy of small intestinal submucosa covered stent in promoting endothelialization in transjugular intrahepatic portosystemic shunt Wang Xiao-bai, Cao Guang-shao, Zhang Hong, Zhang Yan 2010, 14 (30):  5626-5630.  doi: 10.3969/j.issn.1673-8225.2010.30.028 Abstract ( 139 )   PDF (615KB) ( 317 )   Save BACKGROUND: Endothelialization is the aim of preventing restenosis in intravascular stent and transjugular intrahepatic portosystemic shunt (TIPS) stent. It has been suggested that promoting the recovery of function and integrality of endothelial cells is a new strategy for preventing restenosis after the operations. OBJECTIVE: To investigate the efficacy of endothelialization of the shunts in TIPS by stents covered with small intestinal submucosa (SIS). METHODS: TIPSS porcine models were established, and the porcine were randomly divided into two groups. In the experimental group monofilament braided nitinol stents covered with SIS were implanted into the shunts. In the control group monofilament braided nitinol naked stents were used. After direct portal phlebography at 2 and 4 week spostoperatively, the shunt and the surrounding hepatic tissues were harvested for macroscopical and microscopical observation by scanning election microscope (SEM). RESULTS AND CONCLUSION: According to the portal venography 2 weeks after TIPS, 3 and 1 shunts were respectively occluded in control and experimental groups; 4 weeks after TIPS, 4 and 6 shunts were occluded in control and experimental groups, respectively, and the remainders of the shunts exhibited restenosis in different degrees. The restenosis rate was statistically greater in control group than the experimental group (P < 0.05). According to the microscopical observation and SEM, compared to the control group, more endothelialization occurred in the shunts of experimental group. Morphous and size of the endotheliocyte in the experimental group was well-distributed and arranging approach the direction of blood flow. Results show that SIS is a feasible biological material which can speed up the endothelialization of the shunts of TIPS, but the stents covered with SIS cannot improve the patency rate of the shunts efficiently. Related Articles | Metrics

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Histological changes in rabbit adjacent intervertebral disc following different degrees of vertebral body resection  Zhang Liang, Jin An-min, Gao Liang-bin, Li Jian, Yang Bo, Zhang Zhi, Wang Le 2010, 14 (30):  5631-5634.  doi: 10.3969/j.issn.1673-8225.2010.30.029 Abstract ( 118 )   PDF (445KB) ( 276 )   Save BACKGROUND: It remains unclear whether partial vertebral body resection affects nutrition path of intervertebral disc, thereby leading to degeneration of intervertebral disc. OBJECTIVE: To investigate the impact of the degrees of vertebral body resection in rabbit on degeneration of adjacent intervertebral disc. METHODS: A total of 10 New Zealand rabbits were divided into two groups according to the degrees of resection of vertebral body (1/2 and 3/4). At 6 months after operation, the intervertebral disc adjacent to the injured vertebrae and the normal intervertebral disc (normal control) were evaluated by means of hematoxylin-eosin staining to determine the number of vascular buds in Cartilage end-plate, and the changes of nucleus pulposus. The vertebral discs were also measured by alcian blue stained and calculated image optical density (IOD) to evaluate the changes of proteoglycan in nucleus pulposus. RESULTS AND CONCLUSION: When the removal of vertebral body was less than 1/2 in anterior decompression, the nutrition condition remained unchanged, so a single segment fusion with anterior bisegment fixation should be considered. If vertebral body resection was more than 3/4, the adjacent intervertebral disc exhibited significant changes in nutritional status and lead to intervertebral disc degeneration. Therefore, double segment fusion with anterior bisegment fixation should be considered. Related Articles | Metrics

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Blocking effect of vector-based small interfering RNA on tumor necrosis factor-alpha gene expression in human U937 cells  Sun Ke-ning,Gao Xi-wu,Wang Zhen, Jin Qun-hua 2010, 14 (30):  5635-5638.  doi: 10.3969/j.issn.1673-8225.2010.30.030 Abstract ( 97 )   PDF (573KB) ( 332 )   Save BACKGROUND: Aseptic loosening of the prosthesis has become the most common complication of total joint replacement and reduces prosthesis lifespan. Tumor necrosis factor-α (TNF-α) is a novel target for treating aseptic loosening. Small interfering RNA (siRNA) as a novel gene blocking technique has been widely used in gene screening, identification, signal transduction and gene therapy. OBJECTIVE: To explore the blocking effect of siRNA on the expression of TNF-α gene in U937 cell line using siRNA eukaryotic expression vector. METHODS: Two TNF-α siRNA cDNAs were synthesized according to the TNF-α gene sequence and cloned into the vector pSilencer4.1-CMV-neo and named pSilencer-T1 and pSilencer-T2, respectively, which were further identified by restriction endonuclease digestion analysis and DNA sequencing. U937 cells were transfected with pSilencer-T1 and pSilencer-T2 by electrotransfer. After G418 selection, the cells were selected, and the interfering effect was detected by RT-PCR. RESULTS AND CONCLUSION: Restriction endonuclease digestion analysis and DNA sequencing results showed that the target segments were cloned into pSilencer4. 1-CMV neo vector respectively. The results of RT-PCR indicated that both siRNA vectors could successfully knock down TNF-α gene expression. The vector-based siRNA on TNF-α gene can effectively knock down TNF-α gene expression. Results showed that pSilencer-T1 and pSilencer-T2, human TNF-α gene siRNA eukaryotic expression vector were successfully constructed and blocked TNF-α gene expression. Related Articles | Metrics

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Effects of xibijuan soup on interleukin 1 beta and tumor necrosis factor alpha levels in knee synovial fluid of rabbits with traumatic synovitis Zhang Jin-song 2010, 14 (30):  5640-5643.  doi: 10.3969/j.issn.1673-8225.2010.30.031 Abstract ( 111 )   PDF (547KB) ( 357 )   Save BACKGROUND: It has been confirmed that xibijuan soup received notable effectiveness in treating traumatic synovitis, however, most of Precious studies are focused on clinical outcomes. OBJECTIVE: To understand the effects of xibijuan soup on interleukin 1 and tumor necrosis factor α (TNF-α) levels in knee synovial fluid of rabbit with traumatic synovitis, and to explore its molecular mechanism. METHODS: Totally of 12 rabbits were randomly divided into model group (limbs) and the traditional Chinese medicine group. The healthy limbs of the model group were served as control group (limb). A total of 18 joints were included. Animals were prepared for models of knee joint synovial damage by stimulating knee joint to redundantly perform single flexion and extension movements. The expression of interleukin 1β and TNF-α in rabbit knee joint fluid was detected by ELISA method.  RESULTS AND CONCLUSION: The levels of interleukin 1β and TNF-α in the model group were greater than those in the control group (P < 0.05). The levels of interleukin 1β and TNF-α were smaller in the traditional Chinese medicine group compared with the model group (P < 0.05). All results revealed that, the pathological process of knee traumatic synovitis is closely associated with levels of inflammatory cytokines IL-1β and TNF-α. The traditional Chinese medicine xibijuan soup can effectively inhibit the inflammatory cytokines, which revealed the therapeutic mechanism of traditional Chinese medicine on traumatic synovitis at the molecular level. Related Articles | Metrics

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Clinical application and main technology of three-dimensional character acquisition using laser scanning     Wang Shu-yi, Tan Jie, Wang Hui-fang 2010, 14 (30):  5646-5649.  doi: 10.3969/j.issn.1673-8225.2010.30.033 Abstract ( 98 )   PDF (566KB) ( 343 )   Save BACKGROUND: Three-dimensional measuring technique is widely used in reverse engineering, quality inspection, virtual reality and other fields, and gradually enters into the medical field at the same time. The data meet clinical requirement and provide accurate simulation about surgery through choosing safe, accurate, rapid and high cost-effective measuring method. OBJECTIVE: To summarize the clinical application of laser scanning and three-dimensional character acquisition and to analyze the main technologies of application. METHODS: Literatures about three-dimensional character acquisition using laser scanning and clinical application were searched from Chinese Journal Full-text database, WanFang database and Sciencedirect Database by the first author. These literatures have been published from 2000 to 2009 were selected. The key terms were “laser scanning, three-dimensional reconstruction and clinical application” both in English and Chinese, respectively. RESULTS AND CONCLUSIONS: Three-dimensional character acquisition using laser scanning was fully capable to meet clinical requirements and has been widely used in the field of orthopedic, plastic surgery, rehabilitation research and so on. Compared with CT, MRI and other traditional methods, it is rapid, accuracy and harmless to human body. Through the researches of main technology of character acquisition using laser scanning, it has been discovered that clinical requirements could be met fully through interrelated technologies. However, there are some problems, such as the segment of data must be given through an interactive or iterative process, cannot be automatically. Development of reverse engineering technology basing on integration, including measuring techniques, reconstruction techniques based on features and integration, collaborative design and digital manufacturing technology based on network, and how to extract characters quickly and accurately, all will be done in the future. Related Articles | Metrics

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Periprosthetic infection following artificial knee replacement Fang Kai 2010, 14 (30):  5650-5653.  doi: 10.3969/j.issn.1673-8225.2010.30.034 Abstract ( 121 )   PDF (672KB) ( 563 )   Save OBJECTIVE: To summarize current state of periprosthetic infection following artificial knee replacement. METHODS: A computer-based online search of VIP was performed for articles related to periprosthetic infection following artificial knee replacement published between January 1998 and October 2009, with the key words “knee joint, total hip replacement, infection”. The data were collected, and references of each article were reviewed. A total of 18 articles were included. RESULTS: Continuous pain and progressive joint stiffness following knee replacement may be a result of infection. Blood sedimentation, C-reactive protein and culture of joint drainage are main indexes of infection. Antibiotics alone cannot treat deep infection, and the prognosis is not favorable. Antibiotic-loaded articulating cement is an effective therapy for injection in revision at stagy II. CONCLUSION: Infection following total knee replacement is very severe complication. It is necessary to diagnose infection early and treat using appropriate methods based on condition of disease. Related Articles | Metrics

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Application and imaging evaluation of endovascular stents in ischemic cerebrovascular diseases Yan Fu-hua 2010, 14 (30):  5654-5657.  doi: 10.3969/j.issn.1673-8225.2010.30.035 Abstract ( 105 )   PDF (688KB) ( 344 )   Save BACKGROUND: Imaging detection has been widely used in clinical ischemic cerebrovascular disease, which is noninvasive, simple and rapid. OBJECTIVE: To observe imaging morphological changes following endovascular stent implantation to explore safety and values of endovascular stent in ischemic cerebrovascular disease. METHODS: A computer-based online search was performed for related articles published from January 1993 to October 2009 with the key words “vascular stent; scaffold; restenosis; endothelialization; imaging evaluation”. Articles related to imaging morphological evaluation of intracranial target vascular restenosis following stenting of different materials. Repetitive studies or Meta analysis was excluded. A total of 30 articles were selected to discuss safety and imaging evaluation of different materials of stent for ischemic cerebrovascular disease. RESULTS AND CONCLUSION: Intracranial target vascular restenosis following stenting of different materials was observed during follow-up by imaging to identify restenosis and confirm cause, which facilitates evaluation of risks and effect of stent materials. Imaging is sensitive, specific and accurate to identify morphological changes following different materials of stent implantation to help material selection and evalution of embolus shedding at lesioned site. Related Articles | Metrics

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Pedicle screw fixation in combination with two different interbody fusions for treatment of degenerative lumbar instability: A retrospective analysis of 27 cases from a same agency in 4 years Zhang Zhi, Li Jian, Yang Bo, Gao Liang-bin, Wang Le, Yin Biao, Zhang Liang, Song Lei, Qiu Qin-ye 2010, 14 (30):  5658-5661.  doi: 10.3969/j.issn.1673-8225.2010.30.036 Abstract ( 86 )   PDF (451KB) ( 411 )   Save BACKGROUND: Good bone fusion is essential for spinal long-term stability. There are many methods of bone fusion. According to the results of some retrospective studiess, interbody fusion is the most reliable way. OBJECTIVE: To investigate the clinical and imaging outcome for the treatment of degenerative lumbar instability with posterior pedicle screw fixation plus carbon fiber cage interbody placement or bone graft interbody placement. METHODS: A total of 27 patients with degenerative lumbar instability were treated with pedicle screw fixation. All patients were randomized to carbon fiber cage interbody placement (CFCIP) group (n=16) and to bone graft interbody placement (BGIP) group (n=11). Two appropriate fusion cages were used following measurement of intervertebral space height, and the vertebral plate and spinouse process blocks were filled in the cage and implaned into the intervertebral space. The fusion status and interbody height were reviewed under radiographic documents and CT.  RESULTS AND CONCLUSION: All patients were followed up for an average of 19 months (range, 16 to 25 months). The neurologic function and back pain improved significantly in two groups. The excellent and good rate was 91.3% in CFCIP group obtained and 89.4% in BGIP group. The fusion rate was 87.5% in CFCIP group, and 90.9% in BGIP group one year after operation. The average intervertebral height of CFCIP group was greater than BGIP group at the end of follow-up. Results show that the pedicle screw fixation displayed good histocompatibility and the average intervertebral height tends to be less following CFCIP compared with BGIP, but the fusion rate and clinical excellent and good rate were no different significantly. Related Articles | Metrics

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Titanium mesh cage and allogenic bone for treating thoracic and lumbar tuberculosis in 23 patients: A follow-up study Gu Shou-shan, Li Yong-min, Wang Xu, Li Jie 2010, 14 (30):  5662-5665.  doi: 10.3969/j.issn.1673-8225.2010.30.037 Abstract ( 133 )   PDF (513KB) ( 501 )   Save BACKGROUND: Grafts slip, fracture, absorbed or intruded into the spinal canal is easy to appear during the treatment of spinal tuberculosis. The shape of titanium mesh cage is high intension tubbiness, and the zigzag edge contacts with the vertebra. This shape can prevent materials slippage observably.   OBJECTIVE: To evaluate the clinical value of combined application of titanium mesh cage and allogenic bone for treating thoracic and lumbar tuberculosis.   METHODS: The 23 cases of thoracic and lumbar tuberculosis including 12 males and 11 females, aged 13-55 years, were retrospectively analyzed. Operative methods, including one-stage anterior radical debridement, anterior and/or posterior fixation and allogenic bone fusion with titanium mesh cages, were used. Postoperative incision concrescence, recovery of tuberculosis symptoms and neurologic function, bone fusion and the recurrence of spinal tuberculosis were observed.   RESULTS AND CONCLUSION: All patients were visited regularly after operation for 1-3 years. The incision became healed for the first stage. The tuberculosis symptoms were significantly improved or disappeared. No titanium mesh allogenic bone fusion or fixation failure, no spinal kyphosis wasobserved. After operation, all patients got exercises out of bed by wearing orthosis 6-12 weeks later and did normal work 6 months later. It can be verified that the one-stage anterior radical debridement, reconstruction with titanium mesh cages and allogenic bone combined segmental fixation is an effective method in the treatment of thoracic and lumbar tuberculosis. It allows spine to obtain immediate and long-dated stability, correct kyphosis and promotes bone grafting fusion.   Related Articles | Metrics

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Metal implant internal fixation based on three-dimensional CT reconstruction: Follow-up of 24 patients with fractures around the knee Liang Ying-jie, Zhang Guang-ming, Wang Jian-wei, Ge Tao 2010, 14 (30):  5666-5669.  doi: 10.3969/j.issn.1673-8225.2010.30.038 Abstract ( 86 )   PDF (417KB) ( 318 )   Save BACKGROUND: Fractures around the knee have been frequently treated by traditional femoral or tibial plate, external fixator or intramedullary nail fixation. But there are many defects, such as extensive soft tissue stripping around fracture fragments, serious breakdown of the local blood supply, increased risks for infection, delayed union, even nonunion. OBJECTIVE: To explore the surgical indications, methods and effects of the Liss Invasive Stabilization System (LISS) for fractures around the knee. METHODS: A total of 24 cases of complex fractures around the knee were selected, including 17 males and 7 females, aged 42 years (18-60 years). They were treated using LISS fixation system based on CT three-dimensional reconstruction. All the operations were performed following AO’s standard operating procedures. After the surgery, the patients were followed-up every week in the first 4 weeks, and then followed-up once a month. Hospital for special surgery knee score (HSS) was used to evaluate the treatment effect. RESULTS AND CONCLUSION: All patients were followed up for 6-24 months. Fracture healed with no occurrence of nonunion. HSS scores revealed 18 cases of excellent, 4 good, 1 fair and 1 poor, resulting in excellent and good rate of 91.67%. The outcome of using Liss fixation system for treatment of fractures around the knee was satisfactory. The soft tissue injury and the disturbance of the local micro-environment are small. It can maximize the protection of local blood supply of fracture, with low infection, high reliability and early active exercise. Related Articles | Metrics

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Comparison of therapeutical effects between titanium elastic nail and Kirschner wire in treating mid-shaft clavicle fractures Qian Jun 2010, 14 (30):  5670-5673.  doi: 10.3969/j.issn.1673-8225.2010.30.039 Abstract ( 141 )   PDF (417KB) ( 395 )   Save BACKGROUND: In recent years, fixation in bone marrow, such as Kirschner wire, has got satisfactory effects in most of patients with mid-shaft fracture of clavicle. However, there are still some complications in part of patients. Titanium elastic nail (TEN) is a common method for treating child long bone fractures.  OBJECTIVE: To compare TEN and Kirschner wire in treat the mid-shaft clavicle fractures, so as to provide clinical evidences for the improvement of treatment of mid-shaft clavicle fractures. METHODS: A total of 46 cases with middle 1/3 of clavicular fracture were underwent surgical treatment, 15 cases using TEN, 31 cases using Kirschner wire. Operation time, hospitalization, healing time of fracture, complications and shoulder function recovery at 3 weeks after surgery were compared. RESULTS AND CONCLUSION: Compared with Kirschner wire group, TEN group had better results in healing time of fractur (P < 0.05); patients in the TEN group could perform early active functional exercises, and the range of motion of affected shoulder was almost the same compared with normal side at 3 weeks after surgery, while Kirschner wire group need to caging the shoulder over 4 weeks and forbid the early active functional exercises. Occurrence of complications: 1 case with nail quit 1 case with nail tail irritation without skin ulceration, no fracture nonunion and fracture stump rotation were found in the TEN group. 7 cases with wire loose, 6 cases with wire tail irritations, 4 cases with wire tail inflammatory sinus tract, 2 cases with fracture displaced or nonunion (changed for reconstruction plate) in the Kirschner wire group. Compared with Kirschner wire, TEN have advantages of less healing time, high recovery rate, less complications, early functional exercises after surgery. Therefore, TEN is a better choice for patients with mid-shaft clavicle fractures. Related Articles | Metrics

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Effect and complications of metallic implants for internal fixation of upper femoral shaft fracture: Randomized comparison among three groups Ouyang Zhen-hua, Huang Jian-rong, Xiang Xu-jin, Huang Bin 2010, 14 (30):  5674-5677.  doi: 10.3969/j.issn.1673-8225.2010.30.040 Abstract ( 126 )   PDF (411KB) ( 712 )   Save BACKGROUND: The upper femoral shaft fracture is clinically treated with internal fixation with metal implant. However, complications occur due to fracture type, operative and internal fixation method or functional exercise postoperatively. There are few reports on the upper femoral shaft following fracture internal fixation system complications and their causes. OBJECTIVE: To observe the clinical results and complications in the upper femoral shaft fracture following different internal fixation methods. METHODS: A total of 92 cases of femoral shaft fractures were selected from Department of Orthopedics, Boji Hospital of Zhongshan University, including 63 males and 29 females, aged 18 to 65 years. They were randomly divided into 3 groups, and respectively treated with interlocking intramedullary nail fixation with Internal fixation group, Compression plate Internal fixation group, Plum nail Internal fixation group, Three groups using the same surgical approach and the conventional internal fixation, 3 groups were observed after surgery in patients with conditions, early complications, long-term complications, clinical, follow-up. RESULTS AND CONCLUSION: The 92 patients with the upper femoral shaft fractures were successfully treated with open reduction and internal fixation. The average success rate and the operation time displayed no significant difference among the groups (P > 0.05). The fracture healing time was less, but the cure rate was greater in interlocking nail group and plate fixation group than plum nail group (P < 0.05). The upper femoral shaft fracture, implant bending fracture, fracture nonunion, re-fracture and infection were major complications. Incidence of complications in interlocking intramedullary nail fixation group was lower than the compression plate fixation and plum nail groups (P < 0.05). Results show that interlocking intramedullary nail fixation facilitated fracture healing, but different fracture site and types, and various fixator material intensity and reduction conditions, the individualized treatment should be performed to prevent or reduce complications. Related Articles | Metrics

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Dynamic cervical implant replacement in the treatment of cervical disease in 5 cases: Follow-up results of elastic dynamic stability after anterior cervical decompression and non-fusion Hou Zhen-yang, Xu Yao-zeng, Qian Zhong-lai, Zhou Feng, Chen Liang, Jiang Wei-min, Yang Hui-lin 2010, 14 (30):  5678-5681.  doi: 10.3969/j.issn.1673-8225.2010.30.041 Abstract ( 136 )   PDF (425KB) ( 554 )   Save BACKGROUND: Anterior cervical discectomy and fusion is an effective method for the operative treatment of cervical disease, but some problems appear in long-term clinical practice. OBJECTIVE: To evaluate the security and availability of the dynamic cervical implant (DCI) used in the anterior cervical decompression non-fusion. MATHODS: A total of 5 patients (6 segments) with cervical disease were treated by anterior decompression and replaced by DCI. The JOA score was evaluated preoperatively and 3 days, 3 and 6 months after surgery to observe the recovery of neurological function. Plain radiography was taken to survey the intervertebral space height and mobility. RESULTS AND CONCLUSION: All cases were followed up for 1-6 months. JOA average score increased from 8.5 points to 15.4 points. The prosthesis curve was good. Replaced segment achieved stability and restored partial of normal rang of motion. Cervical stiffness and limitation of activity were not found. The implantation of DCI not only provides elastic dynamic stability, but also restores and sustains intervertebral space height and mobility. Besides, the short-term curative effect is satisfactory. Related Articles | Metrics

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Follow-up of total hip replacement using domestic prosthesis in 33 hips Chang Fei, Yu Qing-wei, Liu Guang-yao, Qu Yang, Zhang Jing-zhe, Wang Jin-cheng 2010, 14 (30):  5682-8685.  doi: 10.3969/j.issn.1673-8225.2010.30.042 Abstract ( 157 )   PDF (323KB) ( 377 )   Save BACKGROUND: Total hip replacement has been widely used in the treatment of severer hip diseases in China. However, most of prostheses are designed according to Caucasian osteometric measurements, whether those prostheses are suitable for Orientals is still in dispute. It is emerging to design prostheses for Orientals, there are few reports addressing therapeutic effect after replacement.  OBJECTIVE: To follow up the long-term results of total hip replacement using domestic designed dual-assembly total hip prosthesis. METHODS: Totally 30 patients (33 hips) who underwent total hip replacement at the Department of Orthopaedic Surgery, China-Japan Union /Affiliated Hospital of Jilin University, from June 1987 to December 1996, were followed up. The designed dual-assembly total hip prosthesis was produced by Central Iron & Steel Research Institute, which was similar to bipolar prosthesis with a polyethylene acetabular cup. First generation cementing techniques were applied. The average age at the time of the operation was 56.5 years (30-81 years) and the average follow-up period was 8.5 years (5.0-14.4 years). Standard anteroposterior radiographs of the hip and clinical examinations were used to analyze therapeutic efficacy. RESULTS AND CONCLUSION: The total excellent and good rate was 68.6%. The imaging examination showed that there were 16 hips (48.5%) had aseptic loosening and 11 hips (33%) had heterotrophic bone formation. Additionally, two cases suffered from infection and one case suffered from dislocation. The utilization of prosthesis achieved certain curative effects. However, the design and cement technology have problems due to limitation of conditions, which should be solved in further experiments.  Related Articles | Metrics

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Design and clinical application of HZ-01-A level detector and pressure monitor Li Jing-wen, Long Cun, Lou Song, Wei Xi-guang 2010, 14 (30):  5686-5689.  doi: 10.3969/j.issn.1673-8225.2010.30.043 Abstract ( 116 )   PDF (363KB) ( 387 )   Save BACKGROUND: Mortality related to cardiopulmonary bypass can be lowered by intra-operative monitoring system. Monitoring liquid level and pressure is extremely indispensable for examination of cardiopulmonary bypass (CPB). OBJECTIVE: To design a CPB safety system including an arterial line pressure monitor and low-level sensor, and to evaluate its safety and effects in clinical settings. METHODS: The safety system was composed of pressure transducer, photoelectric transmitter, photoelectric detector, core controller, and liquid crystal display. The principles of reflection and refraction were applied to the design of level sensor. The pressure measurements were converted into electronic signals and processed. According to two principles above-mentioned, fluid level detector and pressure monitor were designed. Thirty patients with the age of 1-75 years receiving cardiac surgery with cardiopulmonary bypass were enrolled. The arterial line pressure at different pump flows was measured and the alarm function of the level sensor was also validated. RESULTS AND CONCLUSION: Cardiopulmonary bypass arterial line pressure increased with the pump flow. Arterial line pressure detected by HZ-01-A safety system also increased with the pump flow increasing, which was highly related to the pump pressure. HZ-01-A safety system could alarm when the arterial line pressure and reservoir level exceeded the pre-determined thresholds. HZ-01-A safety system could be safely and effectively applied to clinical cardiopulmonary bypass and improve bypass safety by accurately detecting the pressure and reservoir level. Related Articles | Metrics

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Single cage plus unilateral pedicle screw placement for treating lumbar degenerative instability in 51 cases Yang Qun, Yang Jun, Wang Bo, Jiang Chang-ming, Wu Chun-ming, Ma Kai, Tang Kai 2010, 14 (30):  5690-5693.  doi: 10.3969/j.issn.1673-8225.2010.30.044 Abstract ( 94 )   PDF (300KB) ( 463 )   Save BACKGROUND: Most of the patients suffered from degenerative lumbar instability are treated by exposure both sides and bilateral pedicle screw fixation, which bring highly operative risk, large blood loss and great medical expenditure to patients. OBJECTIVE: To explore the clinical efficacy of single cage plus unilateral pedicle screw placement for treating lumbar degenerative instability. METHODS: Totally 51 cases with lumbar degenerative instability underwent single cage plus unilateral pedicle screw placement were selected, including 32 males and 19 females, aged ranging from 41 to 72 years. 47 cases had single segment involved and 4 cases had two segments involved. All cases experienced unilateral laminectomy and transforamenal lumbar interbody fusion. The therapeutic effect was assessed by Japanese Orthopaedic Association (JOA) score system. RESULTS AND CONCLUSION: The blood loss was 90-430 mL. The surgical time was 100 minutes (85-120 minutes) for single segment and 150 minutes (120-170 minutes) for double segments. The patients were allowed to early ambulation at 2-3 days after operation. Two cases did not get improvement on back-leg pain, but there was no abnormality from CT and MRI recheck, one case felt pain relieved after anti-symptom treatment for 3 months while the other did not relieve. The average JOA scores at pre-operation and 1 year follow-up was 11 (7-13 scores) and 25 (18-27 scores), respectively. The total improvement rate of JOA was larger than 50%. 44 cases were evaluated as fusion and 7 cases as possible fusion. The average fusion time was 5.4 months (4.3-7.1 months). Postoperative X-ray showed no evidence of pedicle screw loosening, broken, or cage displacement. Single cage plus unilateral pedicle screw placement is characterized by simple operation, small blood loss, short operation and few interference to spine, which is a better method for treating lumbar degenerative instability.  Related Articles | Metrics

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Locking plates in treating fractures: Analysis of complications in 25 cases Zhang Quan, Huang Lei, Wang Man-yi 2010, 14 (30):  5694-5700.  doi: 10.3969/j.issn.1673-8225.2010.30.045 Abstract ( 82 )   PDF (372KB) ( 395 )   Save BACKGROUND: The unique design of nail hole and screw of locking plate makes it possible to provide different fixation mechanisms in fracture fixation, which can provide diverse biological environments for bone healing, thus, lead to various healing patterns.   OBJECTIVE: To retrospectively analyze complications of locking plate treatment for fractures in 25 cases.  METHODS: The physical examination results, including injury mechanisms, whether multiple injuries, selection of internal fixation, operation principles, postoperative loading time, and X-ray films recheck, were analyzed subsequently. The numbers and reasons for internal fixation failure, bone nonunion or delayed union were investigated.  RESULTS AND CONCLUSION: Among the 8 cases of internal fixation collapse, 4 were caused by operation lapses, 1 was due to wrong selection of the internal fixation tool, 1 case took place by weight bearing too early, 2 cases were caused by postoperative infections; Among 11 cases of nonunion or delayed union, 6 were caused by severe primary injuries, and 5 by unsuccessful reduction. 2 cases of pain stemmed from hypodermal projection of proximal tibia LISS plate, 1 from postoperative infection. 1 case of long term to be exposed of plate end due to improper location of the plate during the operation was also involved. Essentially, locking plate just is a kind of internal fixation plate. Either the compression plate or the bridging plate, or the combination of the two could be applied in locking plate fixation. Through our study, we found that the pathway leading to the success was built upon an accurate cognition and skillful mastery of AO internal fixation technology, as well as the correct choice of the tool combined with the fine reduction and micro-damage operation. Related Articles | Metrics