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24 December 2010, Volume 14 Issue 52 Previous Issue    Next Issue

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Patellar baja following primary total knee arthroplasty Zhang Jian-bing, Chen Bai-cheng, Li Ran, Zhao Hong-bo, Li Jian-qiang 2010, 14 (52):  9693-9696.  doi: 10.3969/j.issn.1673-8225.2010.52.002 Abstract ( 293 )   PDF (2872KB) ( 418 )   Save BACKGROUND: The rate of complications of patellofemoral joint following total knee arthroplasty (TKA) is about 39%. There are many causes for these complications, and patellar baja, one of important causes for patellofemoral joint problem has been frequently ignored. OBJECTIVE: To investigate the mechanism of patella baja following primary TKA. METHODS: Clinical data of 78 cases (85 knees) undergoing primary TKA knees in Department of Orthopedics, Third Hospital of Hebei Medical University between July 2003 and January 2009, were retrospectively analyzed. According to HSS scores, they were assigned to high scores and low scores groups. X-ray of two groups before and after TKA was compared. Insall-salvati index was used to measure the height of patella and Hofmann’s procedure was used to measure the variation of the joint line. Logistic regression was performed to analyze the correlation of patellar baja with the insall-salvati index and the proximally transferring joint line. RESULTS AND CONCLUSION: The 59 knees in high scores group did not suffered patellar baja; 23 of 26 knees in low scores group occurred patellar baja, and the insall-salvati index was 1.1±0.1 in 6 knees and joint line elevated (7±2.3) mm in 17 knees. Patella baja were correlated with insall-salvati index and elevation of joint line through the logistic regression. The patella baja was caused by the tibial polyethylene thicker than the tibial resecting bone, i.e. elevated proximally transferring joint line and contracted patellar ligament. Therefore, we should maintain the original joint line maximally during TKA and enhance knee rehabilitation as soon as possible to restrain patellar ligament contracture. Related Articles | Metrics

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Three-dimensional CT morphologic measurement of femoral head/neck junction in hip surface replacement Ye Ting-jun, Feng Jian-min 2010, 14 (52):  9697-9701.  doi: 10.3969/j.issn.1673-8225.2010.52.003 Abstract ( 276 )   PDF (483KB) ( 334 )   Save BACKGROUND: The femoral head/neck junction is preserved in hip resurfacing, so femoral head/neck junction could be at great risk of notching, leading to postoperative femoral neck fracture. OBJECTIVE: To analyze the contour of femoral head/neck junction in hip resurfacing surgery. METHODS: Three dimensional CT images were collected from 102 healthy hips. The very cross section which was perpendicular to the long axis of femoral neck was obtained to make an angle of 50° (or 45°, 55°) with femoral shaft through the femoral head/neck junction. The medial-lateral length (a) and anterior-posterior length (b) were measured. A best-fit circle was created to the outer cortex of the section, and a point (point A) most close to the circle at the lateral part of cortex was identified. A line from point A to the circle centre was created to measure the angle (angle α) made of this line and the horizontal line. The medial-lateral length (a) and anterior-posterior length (b) was compared. The angle α and influencing factors were calculated. RESULTS AND CONCLUSION: Medial-lateral length (a) was significantly greater than anterior-posterior length (b), and male was > female. The mean angle α was 27°. There were no correlation between the angle α and length, body mass or gender. Notching is more possible to occur at superior-lateral or inferior-medial side, and is most possible to occur at “superior-lateral-anterior” part. Point A is 27°anterior to the horizontal line. Surgeons should pay much attention to protect it. Related Articles | Metrics

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Establishment and biomechanical analysis of a hree-dimensional finite element model of the knee joint Wang Guang-da, Zhang Zuo-fu, Qi Xiao-jun, Cao Chun-ni, Yu Juan 2010, 14 (52):  9702-9705.  doi: 10.3969/j.issn.1673-8225.2010. 52.004 Abstract ( 341 )   PDF (338KB) ( 413 )   Save BACKGROUND: Finite element analysis has been frequently used for knee joint biomechanics at abroad. However, there are domestic three-dimensional finite element analyses in China, and the model is simple and rough. There is no report about three-dimensional finite element model of intact knee joint including meniscus, articular cartilage and ligaments. OBJECTIVE: To establish a three-dimensional finite element model of intact knee joint.  METHODS: SCT scanning data of normal knee joint were used to establish intact three-dimensional finite model of knee joint using Mimics, 3ds Max and ANSYS software. Biomechanics of the knee joint model was analyzed to verify the validity of the model. RESULTS AND CONCLUSION: An intact three-dimensional finite element model of knee joint was established successfully, and the model provides a precise anatomic morphology of the knee joint. The finite element analysis of the model demonstrated that the forward loading mainly distributed at the anterior cruciate ligament, medial mesooecium bear larger axial loading than lateral mesooecium; the tibiofibula shifted forward for 4.9 mm. Results primarily show that it is reliable and accurate to build three-dimensional finite element models with CT scan data, which is appropriate to establish the three-dimensional finite element model in orthopedics. Related Articles | Metrics

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Establishment and validation of a fluid-solid coupling finite element model of the lumbar motion segment Chen Hao, Yu Xiao-hua, Hua Guo-jun, Hu Yi-ping, Fan Rong 2010, 14 (52):  9706-9709.  doi: 10.3969/j.issn.1673-8225.2010. 52.005 Abstract ( 319 )   PDF (313KB) ( 754 )   Save BACKGROUND: Fluid related biomechanical behavior of intervertebral disc is difficult to acquire from traditional research on spinal biomechanics. A few porous elastic finite element models are applied to investigate the behavior of lumbar two-phase at abroad. However, there are rarely related reports in China. OBJECTIVE: To establish the fluid-solid coupling finite element model of the lumbar motion segment by the ANSYS12.1 software and to promote the wide application of finite element method in the spinal biomechanics. METHODS: Spiral CT scan was performed in the L4-5 motion segment of a male volunteer without any spinal disease. The CT data was imported to the software of Mimics10.01 to create the geometric model of the L4-5 motion segment which was re-constructed to the 3D NURBS surface with the software of Gomagic9.0. The solid model was established using ANSYS12.1 software, and the model included cortical bone, cancellous bone, cartilaginous endplates, nucleus pulposus, and annulus matrix. A three-dimensional fluid-solid coupling finite element model of the L4-5 motion segment was established after a series of processes such as assigning parameters, meshing models, boundary setting, loading and solution. The height change of intervertebral disc of the model was compared with the vivo results to verify the validity of the model. RESULTS AND CONCLUSION: The established fluid-solid coupling finite element models of L4-5 motion segment has 210 718 nodes and 85 973 elements. The height change of the intervertebral disc was consistent with that of the in vivo results. The fluid-solid coupling finite element model of porous media has accurately simulated biomechanical features of human lumbar spine. Related Articles | Metrics

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Limb-salvage treatment for tumors in acetabular region under the computer-assisted navigation system Xu Jian-qiang, Wan Rong, Zhang Wei-bin, Hao Ping, Yang Yao-qi, Ding Xiao-yi 2010, 14 (52):  9710-8714.  doi: 10.3969/j.issn.1673-8225.2010. 52.006 Abstract ( 355 )   PDF (303KB) ( 382 )   Save BACKGROUND: Limb length discrepancy (LLD) influences the effect of limb-salvage treatment. Although through perspective of monitoring to ensure limbs isometry during operation, it is still a difficult problem to grasp, especially for limb-salvage treatment of malignant tumors in acetabular region. In other aspects of orthopedics, such as spinal column and joint, navigation technology has been more used to the installation of internal fixation and prosthetic placement. OBJECTIVE: To retrospectively analyze the effect of limb-salvage treatment of malignant tumors in acetabular region under the computer-assisted navigation system. METHODS: From January 2001 to June 2009, a total of 11 malignant pelvic bone tumors cases received treatment at the Department of Orthopedics, Shanghai Ruijin Hospital were selected. They underwent preoperative pathological diagnosis; custom-made prosthesis reconstruction was applied after tumor resection, including 8 cases underwent normal limb salvage surgery; the remaining 3 cases were treated with computer-assisted navigation limb salvage. The pelvic malignancies resection scopes of all patients were located in acetabular surrounding region (pelvic areaⅡ). Patients were examined clinically and radiographically after the treatment of limb salvage, and were assessed by lower extremity limb salvage function musculoskeletal tumor society (MSTS) score. RESULTS AND CONCLUSION: In 12-16 months follow-up, 8 cases with normal limb salvage, the mean operation time-consuming was 7.6 hours, and the mean volume of blood loss was 2 400 mL. One case was died of lung metastasis at 3 years after surgery, one case suffered from amputation because of local recurrence. In addition to these two patients, the deviation of acetabular prosthesis exceeded 2 cm to form LLD in 3 cases after the treatment of limb salvage. The mean MSTS score was 20.3 points. Among the 3 cases treated with computer-assisted navigation limb salvage, the mean operation time-consuming was 8.3 hours, and the mean volume of blood loss was 2 100 mL. No cases represented LLD. The mean MSTS score was 21.7 points. It is indicated that limb-salvage treatment of malignant tumors in the acetabular region under the computer-assisted navigation system can cut bone precisely, place prosthesis accurately, reduce the incidence rate of LLD in the acetabular region after the treatment of limb salvage, and improve affected limb function. Related Articles | Metrics

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Significance of spiral CT three-dimensional reconstruction in classification diagnosis and treatment of ankle joint fracture Xin Chun, Yang Liu-cai, Li Shi-hong 2010, 14 (52):  9715-9718.  doi: 10.3969/j.issn.1673-8225.2010. 52.007 Abstract ( 375 )   PDF (459KB) ( 281 )   Save BACKGROUND: The number, displacement, joint surface of ankle joint fracture and fracture fragments of joint space are very complex under different external forces, which are not well shown by X-ray plain film. Although axial two-dimensional CT has high resolution and no-overlapping image, there is difficulty in accurate and complete evaluation of fracture fragments. OBJECTIVE: To investigate the clinical value of spiral CT three-dimensional reconstruction in classification diagnosis and treatment of ankle joint fracture. METHODS: A total of 36 patients with ankle joint fracture received spiral CT three-dimensional reconstruction. The Danis-Weber classification of ankle joint fracture was diagnosed. According to the results, project of internal fixation was formulated, and the excellent operation way was selected. Curative effect was evaluated according to Barid-Jackson standard. RESULTS AND CONCLUSION: Results of spiral CT three-dimensional reconstruction showed there were 22 type B patients (61%) and 14 type C patients (39%) in 36 patients with ankle joint fracture. The therapeutic effects showed there were 19 excellent patients (53%), 13 good (36%) and 4 fair (11%) in 36 patients with an excellent and good rate of 89%. Spiral CT three-dimensional reconstruction can really reflect the lesions of ankle joint fracture. It has clinical significance in classification diagnosis and treatment of ankle joint fracture. Related Articles | Metrics

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Visual images of scapular complex fracture on multi-slice spiral CT multiplanar reconstruction  and shaded surface display Qian Bin, Fang Xiang-ming, Zhu Zong-ming, Tao Guang-yu, Li Wei 2010, 14 (52):  9719-9722.  doi: 10.3969/j.issn.1673-8225.2010. 52.008 Abstract ( 354 )   PDF (406KB) ( 353 )   Save BACKGROUND: Due to the complex structure of the scapular fracture, X-ray plain film examination easily leads to misdiagnosis. With multi-slice spiral CT and three-dimensional reconstruction technology, three-dimensional reconstruction images can be intuitive, three-dimensional, multi-faceted to show fracture features. OBJECTIVE: To evaluate application value of multi-slice spiral CT multiplanar reconstruction (MPR) and shaded surface display (SSD) reconstruction in the scapular fracture. METHODS: Multi-slice spiral CT was used to scan 26 patients with complex fractures of the scapula. All data were entered into the computer workstation, followed by MPR and SSD reconstruction of post-processing to obtain the three-dimensional images of high-resolution. From different angles the fracture line courses, fracture displacement and angulation of the situation were observed, and fracture classification and simulation of surgical approach were performed based on three-dimensional image. RESULTS AND CONCLUSION: Multi-slice spiral CT MPR and SSD reconstruction image fully displayed the location and extent of scapular fractures, with accordance rate between image and actual condition of 100%. A total of 26 cases suffered two or more fractures for a total of 81 fractures. According to standard Hardegger classification, there were 28 cases of scapular body fractures, 13 of scapular neck fractures, 11 fractures of labrum, 9 of glenoid fossa central transverse fracture, 8 of acromion fracture, 6 of scapular fracture, and 6 of coracoid process fracture. Results suggest that multi-slice spiral CT MPR and SSD reconstruction image shows visual images of scapular complex fracture, which are significant for the classification of the scapula fracture type, surgical approach and fixation selection, and effective for the diagnosis of scapular complex fracture. Related Articles | Metrics

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Design and implementation of VC-based bone-mode automatic matching system Zhan Li-bo, Qin Dong-jing, Li Xiang-lin 2010, 14 (52):  9723-9725.  doi: 10.3969/j.issn.1673-8225.2010. 52.009 Abstract ( 222 )   PDF (208KB) ( 255 )   Save BACKGROUND: Using computer technology can realize the orthopedic operation simulation based on measurement and analysis of patients diagnosed image, in order to determine the validity of surgery. OBJECTIVE: To design a set of long bone and bone-mode auto-matching system based on computer image processing technology. METHODS: Through the analysis on clinical pictures of the long bone, the exact image datum of bone-mode was obtained. Based on the datum, the bone-mode was searched from the database which matched with the skeletal, and automatic simulation of matching was performed. RESULTS AND CONCLUSION: In a very short period of time, the system can find a suitable bone-mode which can match the bone. Results demonstrate that the system could improve the efficiency of matching, as well as the success rate. It could reduce the surgery time and suffering of the patents. Related Articles | Metrics

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Establishment of a three-dimensional finite element model of skull base using spiral CT image Liu Wen-fang, Wang Fei, Song Zhe, Ren Guo-shan 2010, 14 (52):  9726-9729.  doi: 10.3969/j.issn.1673-8225.2010. 52.010 Abstract ( 300 )   PDF (318KB) ( 389 )   Save BACKGROUND: In recent years, a large number of biomechanical experiments have conducted to attempt to explain the correlation of craniocerebral injury with stress size and injury site. However, studies on skull fracture cause mainly focus on direct violence, and very little is known about the stress distributions in the skull exposed to indirect violence. OBJECTIVE: Using spiral CT data, three-dimensional reconstruction software, and finite element analysis software, to establish a three-dimensional finite element model of the skull in the ordinary PC. METHODS: Normal adult women were selected, free of head or neck injury, surgery or other history of disease. X-ray routine examination was performed to exclude organic disease, followed by head spiral CT TLC scanning. Image data were input into medical image and 3D reconstruction software MIMICS to establish the three-dimensional visualized model of the skull. The simplified model was optimized and introduced to finite element analysis software ANSYS 10.0 to establish three-dimensional finite element model of the skull. RESULTS AND CONCLUSION: The entity model of the skull base was composed of frontal bone, sphenoid, ethmoid, temporal bone and occipital bone. Since the adults’ sutures are closed, the skull is viewed as a whole. The entity model was meshed to create a 3D finite element model which consisted of 51 053 units and 80 273 nodes. The established finite element model of the skull base is verisimilar geometrically, which can be used in the biomechanic research. Related Articles | Metrics

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Amendatory measurements on panoramic radiographs using reference pins Wu Wen-lei, Ji Li, Zhong Xiao-long 2010, 14 (52):  9730-9734.  doi: 10.3969/j.issn.1673-8225.2010. 52.011 Abstract ( 305 )   PDF (247KB) ( 258 )   Save BACKGROUND: The diagnosis and treatment of periodontal disease often requires measuring alveolar bone height and root length, but the validity of panoramic radiographs for quantitative measurement is still controversial. OBJECTIVE: To evaluate the reliability of vertical lineal measurement on panoramic radiographs by means of amendment with reference pins. METHODS: Permanent teeth of 20 orthodontic cases patients were selected. 5.00 mm steel balls were embedded in molar, premolar and incisor models as the measuring objects, and the reference pins of 10.0 mm length were placed on corresponding position with the ball as the reference standard. Panoramic radiographs of model were taken to measure the vertical diameter of ball images. The measurements were calibrated and corrected using reference pins. The variation between image measurements of steel balls on panoramic radiographs and their true values was compared. RESULTS AND CONCLUSION: When using single reference or average reference of several pins, the distortion rate of panoramic measurements varied on different regions and different placement of reference pins, more than 5% in some regions. The accuracy of the results could be improved using reference pins which were completely perpendicular to occlusal plane to amend the vertical lineal measurement on panoramic radiographs. Here, all distortion rates were less than 1%, and the amendatory results were independent of calibration methods. Whereas the amendatory results were not satisfactory when using reference pins attached the surface of the alveolar of models. Related Articles | Metrics

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An robust automatic contour extraction method for skeletal bone age X-ray images Ran Long-ke 2010, 14 (52):  9735-9738.  doi: 10.3969/j.issn.1673-8225.2010. 52.012 Abstract ( 300 )   PDF (350KB) ( 365 )   Save BACKGROUND: Due to the non-uniform and complexity of bone age X-rays images, the results of contour extraction in automatic skeletal bone age assessment are often unsatisfactory. OBJECTIVE: To extract palm contour automatically using computer to lay a foundation for image pretreatment of bone age assessment to eliminate subjectivity and uncertainty in bone age assessment. METHODS: Bone age X-ray film was analyzed, and a feasible and effective program on the background image sub-sampling was proposed. Two-dimensional third order linear regression method was proposed to simulate the background images. Using a series of operations including morphological and binary image labeling, the contour of the hand was successful extracted. RESULTS AND CONCLUSION: By combining outliers removal with regression, a fixed threshold was used, which avoids selection of appropriate threshold. Moreover, it is robust. Numerous studies have demonstrated that the success rate of hand contour extraction was over 93%, so this method can be fully used in automatic identification of bone age research. Related Articles | Metrics

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MR image denoising based on nearly shift-insensitive and nonredundancy discrete wavelet transform　 Shi Hong-li, Luo Shu-qian 2010, 14 (52):  9739-9743.  doi: 10.3969/j.issn.1673-8225.2010. 52.013 Abstract ( 403 )   PDF (430KB) ( 531 )   Save BACKGROUND: The imaging mechanism of MRI means there is a contradiction between the time/space resolution and signal noise ratio (SNR). Thus, the image denoising becomes very necessary. The image denoising method using discrete wavelet transform (DWT) has been applied widely. However, DWT has some drawbacks. The drawbacks of DWT have led to the development of shift insensitive wavelet transforms, e.g. Kingsbury’s double-tree complex wavelet transform (DTCWT), which necessarily leads to considerably redundant wavelet representation and a huge increase in computational complexity. OBJECTIVE: To design wavelet filter to reduce influence in sampling and maintain non-redundancy of DTCWT and analyze denoising of Rician noise of MRI images. METHODS: The shift sensitivity was mainly caused by the aliasing terms in the downsampling of wavelet decomposition. A new scheme was proposed to approximately eliminate the aliasing terms while remains the wavelet representation free from redundancy. The framework of the proposed DWT was similar to that of the general DWT except that the wavelet filters satisfy some additional requirements beyond the requirements on wavelet filters. A biorthogonal wavelet was designed. The proposed wavelet was applied to denoise the magnetic resonance image with Rician noise using general the thresholding method. RESULTS AND CONCLUSION: A new method for designing wavelet filter, which simplifies the design procedures into an optimal procedure with constraint conditions. The designed biorthogonal wavelet was used in MR images. The simulation results show the superiority of the proposed wavelet in the term of SNR. Related Articles | Metrics

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A bias field fitting method based on MR entropy for cerebral infarction rats Dong Jie, Zhou Zhen, Liu Chun-hong, Wang Ying, Zhang Yu 2010, 14 (52):  9744-9747.  doi: 10.3969/j.issn.1673-8225.2010. 52.014 Abstract ( 336 )   PDF (427KB) ( 348 )   Save BACKGROUND: In MR imaging, especially at high field strength, non-uniform RF coil response is a difficult problem to avoid. It is reflected as a smoothly but non-linearly varying bias field, which modulates tissue intensities across the acquired image. Such inhomogeneties degrade image quality in general and impede segmentation. OBJECTIVE: To propose a model independent correction method of complex image signal bias field based on image data entropy. METHODS: Data were collected by MR device (GE Signa 1.5T). MR images of the cerebral infarction rats were obtained (imaging slice thickness 6 mm, gap 1 mm), except for 3D T2WI (imaging slice thickness 2 mm, gap 0.5 mm). The method was to optimize and remove the bias field depending on 2D entropy. RESULTS AND CONCLUSION: This method was compared to other methods on a number of simulated and real MR images. Compared with traditional methods, the tissues distribution and comparison were more obvious in the histogram, which ease segmentation and extraction. Compared with traditional methods, this method is more effective under low-density Delaunay triangulation, but costs more time under high-density Delaunay triangulation. Related Articles | Metrics

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Visualization toolkit-based spatial location registration of magnetic resonance spectroscopic multi-voxel Zhong Hua, Qi Jing, Weng De-he, Sun Yu, Wan Sui-ren 2010, 14 (52):  9748-9751.  doi: 10.3969/j.issn.1673-8225.2010. 52.015 Abstract ( 412 )   PDF (767KB) ( 885 )   Save BACKGROUND: Magnetic resonance spectroscopy known for its non-invasive and non-destructive nature, has been widely applied in biomedical and clinical research. Especially it has a profound contribution in the diagnosis and therapy of cerebral tumor. OBJECTIVE: The spatial location registration of magnetic resonance spectroscopic multi-voxel can help doctors to find out the location of diseased tissue in brain accurately. METHODS: Utilizing the development tool of visualization toolkit (VTK), the virtual 3D voxel and 2D medical image were reconstructed in space coordinates. In addition, the relative spatial location of the multiple voxels, the single voxel of the multiple voxels and the image was retrieved. RESULTS AND CONCLUSION: The spatial location registration of magnetic resonance spectroscopic multi-voxel is realized based on VTK. Related Articles | Metrics

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Three-dimensional imaging of multi-slice spiral CT angiography with low concentration and low dose iodine contrast agent in canine carotid artery  Zhai Feng-xin, Niu Yu-jun, Wang Zhi-ming, Lei Zhen 2010, 14 (52):  9752-9755.  doi: 10.3969/j.issn.1673-8225.2010. 52.016 Abstract ( 415 )   PDF (278KB) ( 432 )   Save BACKGROUND: With a large number of applications of iodine contrast agent in enhanced CT examination, the adverse reaction has also been attracted a widespread attention. Under the premise of without affecting the diagnostic quality of CT images, the use of low concentration and low dose iodine contrast agent reducing the toxic reactions of the body have important research value. OBJECTIVE: To verify the feasibility of low concentration and low dose iodine contrast agent in carotid artery imaging of canine. METHODS: Three different concentrations of iodine contrast medium (370 mgI/mL, 350 mgI/mL, 300 mgI/mL) were divided into 9 experimental groups (high dose, medium dose, and low dose groups). Three canis familiaris were received multi-slice spiral CT angiography carotid artery imaging repeated sweep, 8 times scanning for each group. The original data were undergoing three-dimensional reconstruction, including volume reconstruction and multi-planar reconstruction; two-dimensional imaging, including maximum intensity projection and surface reconstruction. Vascular edge and development of vascular branches were scored by two radiologists. RESULTS AND CONCLUSION: The score results showed that the vascular edge (score > 2 points) and the development of vascular branches (score > 3 points) display good in canine carotid artery imaging. The edge of canine carotid artery imaging and the branch carotid artery imaging have strong consistency, the Kappa values were 0.799, 0.733, respectively. There was no significant difference between the edge of artery and branch artery imaging of pairwise comparison in 9 experimental groups (P > 0.05). It is indicated that the application of low concentration and low dose iodine contrast agent can obtain good multi-slice spiral CT canine carotid artery CTA angiography image. Related Articles | Metrics

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Correlation between ligamentum flavum hypertrophy and lumbar spinal stenosis by measurement of CT image Kan Min-hui, Cheng Ai-guo, Du Ning 2010, 14 (52):  9756-9759.  doi: 10.3969/j.issn.1673-8225.2010. 52.017 Abstract ( 349 )   PDF (293KB) ( 415 )   Save BACKGROUND: CT examination can measure spinal canal diameters and analyze stenosis type, appearance, degree, and correlation with surrounding tissues to help diagnose lumbar spinal stenosis (LSS). OBJECTIVE: To analyze the effect of the degenerative and hypertrophied lumbar ligamentum flavum on LSS by measurement of CT image. METHODS: Ligamentum flavum specimens were obtained from a total of three groups of patients: LSS, lumbar disc herniation (LDH) and spinal fractures. These slices were selected for hematoxylin-eosin staining to observe the pathologic features. The CT scan was used normally in LSS and LDH groups. The thickness of the capsular portion of the ligament and the front-back oblique diameter of lumbar canal were measured in different lumbar interspace. Intervertebral disc plane and vertebral arch superior thyroid notch plane were selected for measuring the two data. The thickness of ligamentum flavum and its relationship to LSS were analyzed by computing the ratio of the thickness to the front-back oblique diameter of lumbar canal. RESULTS AND CONCLUSION: The mean thickness of ligamentum flavum was greater than (4.79±1.07) mm, and ratio of ligamentum flavum thickness to the front-back oblique diameter of lumbar canal was greater than 0.41±0.08 in LSS group, and (3.18±0.71) mm, and 0.26±0.07 in LDH group. The difference between LSS and LDH was statistically significant (P < 0.01). The ratio of ligamentum flavum thickness to the front-back oblique diameter of lumbar canal was significantly greater in LSS group compared with LDH and spinal fracture groups. Results demonstrated that the measurement of thickness of ligamentum flavum (> 4 mm) and ratio of ligamentum flavum thickness to the front-back oblique diameter of lumbar canal ≥0.41 may function as one of indexes of choosing LSS operable indication. Related Articles | Metrics

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Positron emission tomography image reconstruction algorithm based on an exponential Markov random field prior model Liu Yi, Gui Zhi-guo, Zhang Quan, Shi Hai-jie 2010, 14 (52):  9760-9763.  doi: 10.3969/j.issn.1673-8225.2010. 52.018 Abstract ( 445 )   PDF (376KB) ( 381 )   Save BACKGROUND: Maximum likelihood expectation maximization (MLEM) algorithm, the classical algorithm in PET reconstruction, is superior to filtered back projection reconstruction with its better performance in resolution and noise characteristic. However, with the increasing iterations, the noisy influence of reconstruction image increases. OBJECTIVE: To propose a maximum a posteriori (MAP) reconstruction algorithm based on exponential prior distribution for noise suppression METHODS: Exponent prior distribution replaces the Gaussian of traditional MAP, and the reconstruction image is tested with signal-to-noise and root mean squared error. RESULTS AND CONCLUSION: Results show that the proposed method performed well for noise suppression, and preferably keep the edges of reconstruction image without excessive smoothing. Related Articles | Metrics

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Establishment of a three-dimensional visible model of pterygopalatine fossa and endoscopic anatomy analysis Wang Xiao-lu, Li Jian, Shan Xi-zheng, Gao Jian-hua　 2010, 14 (52):  9764-9767.  doi: 10.3969/j.issn.1673-8225.2010. 52.019 Abstract ( 305 )   PDF (312KB) ( 375 )   Save BACKGROUND: A thorough anatomical knowledge of the pterygopalatine fossa (PPF) is important for PPF surgery. It is very important to develop an digitized visible model that could illustrate the endoscopic anatomy of the PPF and familiarize the endoscopic surgeon with its complex anatomy. OBJECTIVE: To develop a digitized visible model to demonstrate the endoscopic anatomy of PPF to provide surgical instruction for transpterygoid approach. METHODS: According to coronal CT data of one patient, a digitized visible model of the PPF was established by MOI and SketchUp software package. The model was put in the ideal model of the nasal cavity. The wide nasoantral window was opened and the posterior antrum wall was removed to provide access to the PPF. The spatial directions were observed. RESULTS AND CONCLUSION: 3D model of PPF and their adjacent structures was successfully established for endonasal endoscopic surgery, allowing the user to interact with the data and manipulate them (X-ray, internal observation). The model can be observed in special visual field, providing accurate morphological data for surgery guidance plan. Using an endoscopic approach, the internal maxillary artery and its branches, descending palatine artery, sphenopalatine artery, posterior nasal artery, foramen rotundum, pterygoid canal, sphenoid sinus, infraorbital fissure, optic nerve canal pterygoid process of the sphenoid, and internal carotid artery were observed. The transformations of the spatial directions were observed. The method for creating digitized visible models using MOI and SketchUp software package is simple and feasible. This model provides the means to learn the endoscopic anatomy of the PPF and may be used for the simulation of surgical techniques. References | Related Articles | Metrics

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Pulse analysis based on image sequence 　 Zhang Ai-hua, Li Yun 2010, 14 (52):  9768-9771.  doi: 10.3969/j.issn.1673-8225.2010. 52.020 Abstract ( 313 )   PDF (304KB) ( 607 )   Save BACKGROUND: Sensor for pulse signal detection is one or multi-point pressure sensor. One-point pulse signal or several pulse signals cannot completely reflect pulse tracings information. OBJECTIVE: To analyze and extract features of two-dimensional pulse image of space domain and frequency domain. METHODS: The dynamic pulse image sequences of bionic hand were collected by pulse image sensor, which was self-made based on CCD monocular camera. According to the change of grid area in each frame, the three-dimensional displacement variation of multiple points from pulse image surface was obtained. The data of 8 grid points selected in pulse length and 441 frames selected in time axis were formed into two-dimensional matrix, then it was transformed into two-dimensional gray scale image. The features of each two-dimensional pulse image were analyzed and extracted in image domain and frequency domain. RESULTS AND CONCLUSION: With this method, we can obtain the displacement variation of multiple points from the surface of pulse image, and classify pulses according to the features analysis.　 Related Articles | Metrics

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Analysis and evaluation on the principle of realignment of the statistical parametric mapping software package Wang Chao, Du Jian-ping, Yan Bin, Wang Da-hui, Shi Da-peng 2010, 14 (52):  9772-9776.  doi: 10.3969/j.issn.1673-8225.2010. 52.021 Abstract ( 506 )   PDF (323KB) ( 766 )   Save BACKGROUND: Realignment is an important process in functional magnetic resonance imaging (fMRI) and the first step in the image preprocess of the widely used software package statistical parametric mapping (SPM). The reliability of the results is determined by the effect of realignment process. OBJECTIVE: To analyze the basic principle and the key arithmetic in the process of realignment of SPM, including rigid body transformation, Gauss-Newton optimization and B-spline Interpolation. METHODS: A set of real data were processed utilizing SPM2. Combined with the principle of the realignment, a way to evaluate the effect of the realignment is proposed: measure map and measure quality. RESULTS AND CONCLUSION: Gauss-Newton optimization obtained optimized rigid body transformation parameters; B-spline Interpolation was used to obtain corrected images. Results show that these evaluation indexes can preferably evaluate the principle effect. Related Articles | Metrics

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Principal component of morphological traits of heart using Matlab: A cluster analysis Hou Yuan-yuan, Zhou Ping, Zhang Yun 2010, 14 (52):  9777-9780.  doi: 10.3969/j.issn.1673-8225.2010. 52.022 Abstract ( 393 )   PDF (256KB) ( 419 )   Save BACKGROUND: Cluster of heart according to the characteristics can benefit subsequent statistical analysis and study. Cluster is a multielement method to classify sample or variable according to qualitative similarity. OBJECTIVE: To propose the component-cluster method to describe and classify the shape of cardiac morphology and to comprehensively evaluate the heart indicators in the chest X-ray of Chinese healthy adults. METHODS: We collected 36 chest X-rays of healthy adults, and manually measured 10 indicators, which represented the heart of morphological shapes using the software MxLiteView, We complied principal component analysis and cluster analysis using Matlab. RESULTS AND CONCLUSION: Three principal components variables were extracted by principal component analysis. After cluster analysis using the extracted principal components, the 36 samples were divided into three categories, which represented three different types of heart shape. This method is used to classify the shape of heart morphology rapidly and provides some reference value for statistics and classification study of the heart. Related Articles | Metrics

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Application of modified permutation entropy in heart rate variability analysis Ma Qian-li, Bian Chun-hua 2010, 14 (52):  9781-9785.  doi: 10.3969/j.issn.1673-8225.2010.52.023 Abstract ( 356 )   PDF (303KB) ( 534 )   Save BACKGROUND: Heart rate variability (HRV) contains important information about regulation of cardiovascular system. Various nonlinear dynamics methods and complexity measure have been used for HRV analysis. Recently-proposed permutation entropy is a new complexity measure, which has been widely used due to its conceptual and computational simplicity. OBJECTIVE: To improve the equal-state processing method of permutation entropy based on the characteristics of HRV using same symbol in the permutation symbolic series to represent the equal-states, and to investigate the value of the modified permutation entropy applied to the analysis of HRV via clinically collected data. METHODS: HRV data were from MIT-BIH Fantasia database and BIDMC Congestive Heart Failure (CHF) database on PhysioNet. The databases consisted of three groups, i.e. healthy young, healthy elderly and CHF patients. The data were analyzed using permutation entropy and modified permutation entropy methods. One-way analysis of variance and t-test were utilized for statistical analysis. RESULTS AND CONCLUSION: Both types of the equal-state processing methods of permutation entropy were failed to effectively distinguish three groups, especially between healthy young and healthy elderly groups. In contrast, the modified permutation entropy was able to distinguish three groups effectively, even when applied to short-term heart rate variability data (500 RR intervals, approximately 6-7 minutes). Modified permutation entropy can greatly improve the ability to distinguish the HRV signal under different physiological and pathological conditions. It can characterize the complexity of HRV more effectively than permutation entropy. Related Articles | Metrics

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Effect of fluvastatin on recession of coronary atherosclerotic plaque and its composition: Evaluation by intravascular ultrasound virtual histology Zhang Hou-jun, Shan Shou-jie, Zhang Jun-jie, Zhu Zhong-sheng, Liu Zhi-zhong, Chen Shao-liang 2010, 14 (52):  9786-9789.  doi: 10.3969/j.issn.1673-8225.2010.52.024 Abstract ( 270 )   PDF (433KB) ( 674 )   Save BACKGROUND: Recent years, antiatherosclerotic clinical studies have been conducted, and statins effect has been evaluated by intravascular unltrasound (IVUS). Very little is known about changed in coronary atherosclerotic plaque. OBJECTIVE: To evaluate the effects of medium dosage fluvastatin on coronary atherosclerotic plaque and its composition by gray-scale IVUS and virtual histology-IVUS analysis. METHODS: A total of 22 patients who had been preliminarily clinically diagnosed as coronary heart disease were performed coronary angiography. These selected patients should have at least one major coronary branch whose stenosis extent was 20%-50% by coronary angiography examination with eye measurement. The gray scale IVUS and virtual histology IVUS after selecting the stenosis arteria coronary as target vessel were recorded and the target blood vessel was examined by IVUS. All selected patients were treated with 80 mg fluvastatin for 12 months after the examination. The low density lipoprotein cholesterol and total cholesterol levels of patients before and after the treatment were compared. Meanwhile the plaque volume and composition variation using IVUS were also analyzed. RESULTS AND CONCLUSION: After 12 months of 80 mg fluvastatin, the proportion of dense calcium was significantly increased, and the proportion of necrotic core was decreased, which stabilized plaque. However, the volume of plaque was increased but lumens decreased, not reversing plaque progression. Related Articles | Metrics

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Design and implementation of baroreflex sensitivity monitor system Zhang Yun, Wang Rui, Jia San-qing 2010, 14 (52):  9790-9793.  doi: 10.3969/j.issn.1673-8225.2010. 52.025 Abstract ( 326 )   PDF (320KB) ( 289 )   Save BACKGROUND: In various dangerous layering techniques, baroreflex sensitivity (BRS) is a reliable, accurate, independent predictor for arrhythmia and sudden cardiac death following acute myocardial infarction. Studies commonly utilize pressure and electrocardiogram measurements apparatus to calculate data for BRS. OBJECTIVE: To design and develop BRS monitor system to predict sudden cardiac death reliably and accurately after acute myocardial infarction. METHODS: The developed BRS monitor system was used to acquire all patients’ original pulse wave data using electronic blood pressure monitor which also was self-designed. The electronic blood pressure monitor was accomplished by oscillometric method. Pulse wave signals underwent processes of filtering of hardware and software and magnifying for calculating systolic pressure and diastolic pressure. Subsequently, the heart rate was conversed according to the blood pressure value and finally BRS value was calculated by both average values of blood pressure and heart rate. The blood pressure of the subjects was forcibly changed by intravenous injection of vasoactive substances.  RESULTS AND CONCLUSION: Self-designed BRS monitor system consists of the circuit of the electronic blood pressure monitor, pulse wave processing procedures and BRS calculation program. First, electronic blood pressure monitor was used to get pulse wave data. Then, we wrote computer program that was used to process pulse wave to acquire two groups of data of the blood pressure and heart rate. Afterwards, BRS value was calculated with changing average values of the heart rate and blood pressure. In conclusion, depending on BRS value, we can predict possibility of occurring sudden cardiac death who suffered from acute myocardial infarction. Because the device acquires original data which is used to calculate BRS value only from electronic blood pressure monitor, it is convenient to take. Therefore it is possible to visit patients of acute myocardial infarction at any moment. The development of this monitoring system may provide a better idea to effectively control occurrence of sudden cardiac death after acute myocardial infarction in clinic. Related Articles | Metrics

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Automated detection and identification method for auditory brainstem response waveforms Gao Rui-jing, Sun Ying, Li Yue-nan 2010, 14 (52):  9794-9797.  doi: 10.3969/j.issn.1673-8225.2010. 52.026 Abstract ( 357 )   PDF (265KB) ( 385 )   Save BACKGROUND: Researchers proposed a lot of auditory brainstem response (ABR) automatic detection methods. But these methods were mainly applied to estimate hearing threshold level, and can only detect a finite number of peaks. OBJECTIVE: By studying the ABR waveform characteristics and related mathematical methods, to propose a new peak identification algorithm---cosine summation algorithm, which can more accurately detect all the sensation level and hearing level peaks of ABR. METHODS: ABR detection experiments were performed on 3 Individuals without hearing impairment in Xinhua Hospital. With short sound stimulation, by the stimulus frequency of 23 Hz, at various sound stimulus intensity, 1 024 data points were collected within 10 ms, and a priori experimental data was obtained. With the designed new peak identification algorithm, simulation experiments on each data were carried out, and the accuracy and practicality of the algorithm was tested. RESULTS AND CONCLUSION: The clinical experience values of ABR wavelet peak latency were regarded as the reference values for automatic identification. A large number of experiments showed that the new algorithm can accurately identify each ABR wavelet peak and quickly calculate the values of sub-wave latency and the amplitude. Related Articles | Metrics

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Diagnosis algorithm of sleep apnea syndrome using fuzzy support vector classification Jiang Li-yi, Liu Su-juan, Wu Xiao-ming 2010, 14 (52):  9798-9802.  doi: 10.3969/j.issn.1673-8225.2010. 52.027 Abstract ( 303 )   PDF (428KB) ( 471 )   Save BACKGROUND: Sleep apnea syndrome (SAS) is monitored and examined clinically with polysomnography. However, it is expensive and complex to operate, which significantly affects the natural sleep of human. OBJECTIVE: To evaluate the value of heart rate variability (HRV) in diagnosing SAS, and propose a new method for SAS classification based on fuzzy support vector machine (FSVM). METHODS: Detrended fluctuation analysis and autoregressive model spectrum estimation were used to analyze R-R interval sequence of 38 healthy subjects and 28 SAS subjects during various sleep stages. Scaling exponents of age, gender and HRV at each sleep stage, as well as low/high frequency were selected as SAS characteristic parameters. FSVM was used to classify SAS. RESULTS AND CONCLUSION: Results indicate that the proposed method can diagnose SAS effectively and the classification accuracy rate of SAS is 93.94%. Compared with current SAS diagnosis methods, this method is more simple and accurate. Related Articles | Metrics

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Support vector machine for classifying model of nasopharyngeal carcinoma based on microelement Yang Chun, Du Xi, Du Jun, Tang Bin, Liu Ke, Hu Xin 2010, 14 (52):  9803-9806.  doi: 10.3969/j.issn.1673-8225.2010. 52.028 Abstract ( 315 )   PDF (362KB) ( 367 )   Save BACKGROUND: Support vector machine (SVM) has been successfully used in document classification, handwriting recognition, image classification and bioinformatics. OBJECTIVE: Using intelligent algorithm, to establish model of nasopharyngeal carcinoma (NPC) patients with SVM and microelement data to improve the identification accuracy of NPC. METHODS: NPC was used to classified model of NPC patients and the normal or the other disease patients based on microelement data. The sample was harvested from non-colored hairs, 3 cm from the scalp. The microelement detection included zinc, copper, ferri, manganese, chromium and nickel, in addition to age and sex. The radical basis function is adopted as a kernel function of SVM, and the model adjusts C and σ to build the optimization classifier. RESULTS AND CONCLUSION: The correct classification ratio was 81.71% and 66.47% by 10-fold cross validation. The result shows that the classified model of blood routine based on SVM can classifies the nasopharyngeal carcinoma patients from the normal or the other disease patients. Related Articles | Metrics

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Visualization toolkit-based three-dimensional model of the colorectal segment Yan Rong-guo, Guo Xu-dong, Xu Chang-qing 2010, 14 (52):  9807-9811.  doi: 10.3969/j.issn.1673-8225.2010. 52.029 Abstract ( 392 )   PDF (545KB) ( 570 )   Save BACKGROUND: Converting the two-dimensional (2D) tomographic image sequences into an intuitive three-dimensional (3D) image, exhibiting the 3D structure of human organs and morphology, and providing anatomical information which are not available by traditional methods, are basic tasks to achieve visualization of medical data. OBJECTIVE: To establish a 3D visualization model based upon the intestinal slice data using 3D visualization technology for medical images for tracking the spatial position of a swallowable capsule robot within the intestinal tract, and for numerical simulation researching of intestinal ability to withstand water flushing of patients who suffered from fecal impaction or intestinal obstruction. METHODS: General process of visualization for medical image slices includes image acquisition, registration, 3D surface-rendering reconstruction, and implementation of 3D digital visualization using the visualization toolkit (VTK) in visual C++. RESULTS AND CONCLUSION: Using the VTK software, we implemented 3D digital visualization of colorectal image slices, including its rotation, zoom, pan of the 3D colorectal image, and integrated it into MFC graphical user interface. Actually achieved 3D visualization model could provide a reference image for researching on tracking the spatial position of a swallowable capsule robot within the intestinal tract, and for numerical simulation researching of intestinal ability to withstand water flushing of those patients who suffered from fecal impaction or intestinal obstruction. Related Articles | Metrics

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Remote monitoring software to monitor the whole infusion points based on photoelectric sensor Zhang Yu, Lu Xiao-ying 2010, 14 (52):  9812-9815.  doi: 10.3969/j.issn.1673-8225.2010. 52.030 Abstract ( 316 )   PDF (401KB) ( 418 )   Save BACKGROUND: At present, manual monitoring on venous transfusion is commonly used, and medical personnel should check the monitoring to make sure the infusion speed is reasonable and whether the infusion is completed. If the medicine was not changed or the infusion was not stopped in time, the advantageous treatment time could be delayed or medical malpractice may happen, which affects the safety of patients. OBJECTIVE: To propose an infusion monitoring system based on photoelectric sensor to prevent accidents and improve the efficiency of medical staff. METHODS: The system uses chip AT89C51 as a control center, and the infusion circumstances are monitored by the photoelectric sensor. The wireless communication technology feedbacks the infusion of information to the host computer, so the medical personnel can control the infusion in the host computer by visualization software and cut the infusion when emergency happens. RESULTS AND CONLUSION: The system can monitor and adjust the infusion speed automatically, and monitor progressing of infusion, accompanied by automatic alarming. The medical personnel can monitor the whole points of all transfusion through remote monitoring software. Clinical application of this system can effectively ensure transfusion safety, reduce medical risks, greatly improve the quality of care, reduce the accompanying stress, and meet current needs for clinical transfusion. The system has practical values. Related Articles | Metrics

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Kinematics quantitative analysis of hemiplegia gait by three-dimensional motion analysis system Wang Gui-mao, Yan Jun-tao, Liu Yu-chao, Qi Rui 2010, 14 (52):  9816-9818.  doi: 10.3969/j.issn.1673-8225.2010. 52.031 Abstract ( 344 )   PDF (200KB) ( 374 )   Save BACKGROUND: Three-dimensional kinematic analysis can be used to obtain various biomechanical parameters in walking, which represents advanced level of gait biomechanics. This technique is not mature in domestic application. Current domestic studies mainly focus on analysis of sagittal plane of hemiplegia lower limb.  OBJECTIVE: To explore the characters of the stroke hemiplegia gait using three-dimensional kinematic analysis. METHODS: The 10 hemiplegia gait patients and 10 normal gait volunteers as control were subjected to gait analysis using three-dimensional kinematic analysis system. The basic time-space parameter, gait cycle parameter and pelvis three-dimensional motion angle of normal controls, and the symmetry during motion were analyzed. The three-dimensional motion angle parameters of hip, knee and ankle of two groups were analyzed. The hemiplegia gait character of the lower limb in sagital plane, transverse plane and frontal plane of two groups was compared. RESULTS AND CONCLUSION: The hemiplegia gait manifested as follows: The knee flexion and range of motion were restricted; the hip adduction restricted, abduction and external rotation became larger. The motion analysis system can evaluate hemiplegic gait, quantitatively evaluate the lower limb motion changes, thereby providing the availability information in rehabilitation Related Articles | Metrics

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Numerical analysis of the effect of attachment points of middle ear actuator on stapes movement Liu Hou-guang, Ta Na, Rao Zhu-shi 2010, 14 (52):  9819-9822.  doi: 10.3969/j.issn.1673-8225.2010. 52.032 Abstract ( 325 )   PDF (359KB) ( 303 )   Save BACKGROUND: To overcome problems in conventional hearing aids such as low gain at high frequencies, discomfort in occlusion of the external ear canal and acoustic feedback, middle ear implants have been developed over the past two decades. Different types of middle ear implants always have their actuators stimulated different positions of the ossicular chain. The effect of such stimulating placement on stapes movement is rarely investigated. OBJECTIVE: To analyze the effect of the attachment points of their actuator on the movement of the stapes. METHODS: Based on an established human middle ear finite element model, the same amplitude force was applied at incus body and incus long process, respectively. The direction of the excitation force was changed to simulate errors during operation. The stapes displacements stimulated by these forces were calculated and compared with the one normal sound pressure excited.  RESULTS AND CONCLUSION: Compensating a same level of hearing loss, small exciting force was required when the attachment point of the actuator was set to the incus long process. The stapes displacement was sensitive to the changes in the direction of excitation regardless of which attachment point was selected. With the actuator attached to the incus body, the stapes piston motion was no longer the main component of the stapes motion in the mid-high frequencies when the excitation’s direction changes to 45 degree off the longitudinal stapes axis. Results show that the incus long process is an ideal attachment point for actuator as only a small excitation force is required to compensate the same level of hearing loss. In addition, the stapes piston motion is less sensitive to the changes in the direction of the excitation force in this case. Related Articles | Metrics

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Effect of cervical bioabsorbable cage versus plate systems on intervertebral disc adjacent to operated segments Li Hong-wei, Bao Da, Ge Yan-hu, Zhao Ming, Sun Ji-tong, Luo Xiao-bo 2010, 14 (52):  9823-9826.  doi: 10.3969/j.issn.1673-8225.2010. 52.033 Abstract ( 286 )   PDF (304KB) ( 365 )   Save BACKGROUND: Adjacent segmental degeneration following cervical anterior fusion has become a focus. Semielastic internal fixation system exhibits less influences on adjacent intervertebral disc degeneration compared with commonly used rigid internal fixation systems. OBJECTIVE: Regardless of the intensity of brace, to investigate the effect of cervical bioabsorbable cage or plate systems on intervertebral disc adjacent to operative segments, by pressure monitoring on intervertebral disc adjacent to operative segments. METHODS: A total of 23 dogs of medical fitness were selected, and divided into 3 groups, including 5 in preliminary group (reference value of cervical intervertebral disc was measured), 9 in bioabsorbable cage group treated with bioabsorbable cage devices, and 9 in plate group treated with plate systems. All dogs underwent anterior discectomy on C 3/4, and were implanted with corresponding internal fixators. The pressure of intervertebral disc adjacent to operative segment (C 4/5 ) was measured in the operation. The pressure change from preoperative to postoperative was calculated as the intensity of brace. The animals were sacrificed at 6 months. Pearce grading and histological observation was performed to evaluate upper intervertebral disc degeneration. RESULTS AND CONCLUSION: There were no significant differences between bioabsorbable cage and plate groups in pressure change of intervertebral disc adjacent to operative segments (P > 0.05). Spearman analysis showed that pressure differences in group was positively correlated with Pearce grading, histological grading 6 months following implantation (r=3.13, 2.78, P < 0.05). The intervertebral disc degeneration Pearce grading and histological grading were less in bioabsorbable cage compared with plate system group (P < 0.05). Results show that exorbitant brace pressure can induce the degeneration on dog’s intervertebral disc adjacent to operative segments, and the degeneration was decreased using bioabsorbable cage devices compared with plate systems. Related Articles | Metrics

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Ni-Ti shape memory alloy embracing fixator versus reconstruction plate fixation in treatment of midshaft fractures of the ulna and radius Lü Xiao-hua, Chen Gen-yuan, Qu Guo-xin, Zhang Hui, She Wei 2010, 14 (52):  9827-9830.  doi: 10.3969/j.issn.1673-8225.2010. 52.034 Abstract ( 268 )   PDF (307KB) ( 243 )   Save BACKGROUND: Screw loosening and plate breakage are common factors that affect fracture healing. Ni-Ti shape memory alloy embracing fixator has good mechanics, biocompatibility and low biodegeneration. OBJECTIVE: To compare the clinical outcome of Ni-Ti shape memory alloy embracing fixator and reconstruction plate fixation in treatment of displaced or comminuted midshaft fractures of the ulna and radius. METHODS: A total of 56 patients with displaced or comminuted midshaft fractures of the ulna and radius were surgically treated with either Ni-Ti shape memory alloy embracing fixator or reconstruction plate fixation between April 2004 and March 2009 in Department of Orthopedics, First Hospital of Lanzhou University. Twenty-six were treated with Ni-Ti shape memory alloy embracing fixator and 30 with reconstruction plate fixation. All patients were followed up from 1, 2, 4, 6, 12 months following internal fixation, and forearm function was evaluated using Anderson standards. RESULTS AND CONCLUSION: Compared with reconstruction plate fixation group, Ni-Ti shape memory alloy embracing fixator operating was simpler, took shorter operation time and less blood, and required smaller wound incision (P < 0.05) with wide indications, high excellent and good rate of functional recovery, and early allow for functional exercise. However, there was no statistical difference in terms of hospital stay, time of removing fixation, bone union rate between two groups (P < 0.05). The Ni-Ti shape memory alloy embracing fixator is better than reconstruction plate fixation in treatment of midshaft fractures of the ulna and radius. References | Related Articles | Metrics

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Arthroscopic cruciate ligament reconstruction using hamstring tendon autograft fixed by bioabsorbable interference screw: 27 cases report Wang Qun-li, Yun Xiong, Chen Qi, Luo Wei-guo, Gong Ji-cheng, Xu Xin 2010, 14 (52):  9831-9834.  doi: 10.3969/j.issn.1673-8225.2010. 52.035 Abstract ( 313 )   PDF (343KB) ( 393 )   Save BACKGROUND: Clinical experiments of cruciate ligament reconstruction with hamstring tendon autograft or allograft fixed by bioabsorhable interference screw under arthroscope have been extensively conducted. However, clinical studies are few for the southerners with thin hamstring tendon. OBJECTIVE: To introduce the clinical effect of cruciate ligament reconstruction with hamstring tendon autograft or allograft fixed by bioabsorhable interference screw under arthroscope. METHODS: A retrospective analysis was conducted on 27 cases of cruciate ligament injury, including 24 cases of anterior cruciate ligament (ACL) injury, 2 of posterior cruciate ligament (PCL) injury, and 1 of both ACL and PCL injury, reconstruction with hamstring tendon autograft 23 cases and allograft 4 cases. Periodical examination was done on rehabilitation exercise and knee joint function. Knee joint function was determined by IKDC, Lysholm knee functional scales and Lysholm scores. RESULTS AND CONCLUSION: The 22 cases were followed up for 3-24 months (average 8.7 months). One had saphenous nerve injury; intraarticular infection happened in 1 cases 3 months after operation, and the graft was removed, waiting for the revision reconstruction. All cases except the infected one got normal function of knee joint after operation and knee joint stability was recovered. The temperature of the affected knee was higher in allograft group in several weeks postoperation, but the body temperature was scarcely higher than 38 degree. A total of 19 patients got normal IKDC score, and the average postoperative Lysholm knee functional scales were significantly increased (P < 0.01). Results show that hamstring tendon autograft or allograft is ideal graft for ACL or PCL. Good result was expected for ACL or PCL reconstruction with hamstring tendon autograft fixed by bioresorbable interference screws. Related Articles | Metrics

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Multivariate analysis of risk factors for range of motion in patients with low back pain Ren Xin-yu, Zheng Xiao-yong, Tang Huai-fu 2010, 14 (52):  9835-9837.  doi: :10.3969/j.issn.1673-8225.2010. 52.036 Abstract ( 230 )   PDF (320KB) ( 361 )   Save BACKGROUND: One way analysis of variance has been used to explore the influence of age and degeneration on lumbar spine motion. However, multiple analysis results are few, especially for patients with low back pain. OBJECTIVE: To assess lumbar spine segmental range of motion (ROM) with flexion/extension radiographs using multiple regression analysis. METHODS: A total of 120 patients with low back pain were selected, including 32 females and 88 males with an average age of 51.13 years (ranging 23 to 74 years). Segmental ROM and Kellgren score (KS) of degeneration were assessed. Multivariate analyses were performed for each level. Independent variables evaluated were: ① age, ②sex, ③height, body mass, body mass index, ROM of segment before measurement, ROM at the level above, ROM at the level below (except L5-S1). RESULTS AND CONCLUSION: Body mass index had a significant negative association with ROM at L 1-5. Age had a significant negative association with ROM at L 3-5. KS at the level of interest had significant negative association with ROM only at L5-S1. KS at the below level had significant negative association with ROM only at L 4-5. At adjacent levels, KS, body mass, sex and height did not have a significant association with ROM at any level. Results showed that age and body mass index were the strongest statistical predictors of ROM, and degeneration was a significant predictor of ROM only at L5-S1. Related Articles | Metrics

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Advance in design of artificial knee prosthesis Zhao Qi, Jiang Yao 2010, 14 (52):  9838-9840.  doi: 10.3969/j.issn.1673-8225.2010. 52.037 Abstract ( 298 )   PDF (233KB) ( 532 )   Save The requirements of modern knee prosthesis are to better recover the motor properties of knee joint and reduce the stress and wear between contact surfaces of joint prosthesis. Improved functional performance requires enhanced range of motion, increased motor performance, and creation of kinematic patterns that more closely resemble the normal knee. Considerations to reduce polyethylene wear include increased cross-linking, improved femoral component surface finish, better modular tibial locking mechanisms, and the use of mobile-bearing artificial knee jonit designs that allow increased implant conformity and reduced contact stresses without increasing loads transmitted to the fixation interface. Related Articles | Metrics

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Application of spiral CT three-dimensional reconstruction in knee joint fracture Wang Tie-cai 　 2010, 14 (52):  9841-9844.  doi: 10.3969/j.issn.1673-8225.2010.52.038 Abstract ( 328 )   PDF (322KB) ( 448 )   Save OBJECTIVE: To explore the application value of multi-slice spiral CT three-dimensional reconstruction and posttreatment in knee joint fracture. METHODS: A computer-based online search of PubMed database (http://www.ncbi.nim.nih.gov/PubMed) and CNKI database (www.cnki.net/index.htm) was performed for related articles published between 1995 and 2009, with key words “knee joint fracture, three-dimensional reconstruction, CT scan” in English and Chinese. Repetitive and outdated articles, review articles and Meta analysis were excluded. A total of 28 articles, including 14 Chinese and 14 English, were selected. A total of 50 patients with knee joint fracture underwent X-ray examination, multi-slice spiral CT scanning and posttreatment. Results of the three methods were compared in addition to comparison with intraoperative and postoperative observations. RESULTS: Multi-slice spiral CT three-dimensional reconstruction and posttreatment exhibit significant clinical values in the diagnosis and treatment of knee joint fracture. Multi-plane reconstruction, surface shielding, volume rendering and maximum intensity projection can be used to enhance axial images. Case analysis showed that the diagnosis rate was 88% by X-ray, 100% by multi-slice spiral CT. So multi-slice spiral CT three-dimensional reconstruction can confirm diagnosis and correct typing. CONCLUSION: Multi-slice spiral CT three-dimensional reconstruction can accurately display articular surface fracture that cannot be displayed on common X-ray films, and exhibit superior role in displaying articular cavity and articular surface fractures, identifying fracture type and joint injury over X-ray examination. Related Articles | Metrics

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Elderly intertrochanteric fractures treatment using dynamic hip screw, Gamma nail and external fixation frisket Tang Ke, Duan Xiong-bo 2010, 14 (52):  9845-9848.  doi: 10.3969/j.issn.1673-8225.2010. 52.039 Abstract ( 335 )   PDF (240KB) ( 386 )   Save BACKGROUND: Dynamic hip screw (DHS), Gamma nail and external fixation frisket are widely applied to treat elderly intertrochanteric fractures, but there are no relevant criteria available in the clinical selection. OBJECTIVE: To compare the therapeutic effects of DHS, Gamma nail and external fixation frisket in treatment of elderly intertrochanteric fractures. METHODS: 168 elderly patients with intertrochanteric fractures were divided into three groups, respectively treated with DHS (n=53), Gamma nail (n=58), and external fixation (n=57). The operative time, blood loss, fracture healing time, and postoperative complications were compared, and joint function after operation was observed.  RESULTS AND CONCLUSION: The patients were followed up for 6-35 months. The mean operative time was 99.11 minutes in Gamma nail group, significantly longer than DHS and external fixation groups (P < 0.05). The amount of blood loss in DHS group was most, followed by Gamma nail, and then external fixation group (P < 0.05). The incidence rate of complications in external fixation group was significantly greater than the other groups. There were no differences in fracture healing time or hip joint function recovery (P > 0.05). DHS, Gamma nail and external fixation are effective methods for the treatment of intertrochanteric fractures. Each method has its own advantages and disadvantages. It can achieve satisfactory results with a reasonable choice for the state of illness. Related Articles | Metrics

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Mechanical characteristics of three metal extramedullary implants for elderly intertrochanteric fractures Wang Ya-bin, Zhou Zheng-ming, Zhang Hai-lin, Yin Xiao-jun, Gu Jia-ye, Zhang Yun-qing 2010, 14 (52):  9849-9852.  doi: 10.3969/j.issn.1673-8225.2010. 52.040 Abstract ( 286 )   PDF (240KB) ( 450 )   Save BACKGROUND: Extramedullary fixation methods have been clinically used, such as dynamic hip screw (DHS), proximal femoral locking plate (LCP) and percutaneous compression plate (PCCP). DHS has been considered gold standard for intertrochanteric fractures in elderly people. OBJECTIVE: To compare the clinical outcomes of DHS, LCP and PCCP in the surgical treatment of intertrochanteric fractures in the elderly. METHODS: Clinical data of 124 elderly patients with intertrochanteric fractures were retrospectively analyzed, including 53 cases treated with DHS, 27 with LCP, and 44 with PCCP. The outcomes of the three extramedullary fixations were compared by analyzing operation time, blood loss, complication and postoperative Sander hip injury scores. RESULTS AND CONCLUSION: A total of 96 of 124 cases were followed up with a mean period of 19.8 (range 12-32) months. There were statistically significant differences in the operation time (77.4±7.0, 94.3±12.5, 448.2±9.0) minutes, blood loss (220.4±19.3, 237.4±23.9, 86.9±16.9) mL, among DHS, LCP, and PCCP groups (P < 0.05). However, incidence rate of complication was 16.22% (DHS), 13.04% (LCP), and PCCP (5.56%). There were no significant differences in Sander hip injury score in 3 groups (P > 0.05). Results show that DHS, LCP, and PCCP can be used effectively for the treatment of intertrochanteric fractures. Moreover, PCCP has several advantages, such as shorter operation time, less blood loss and lower complication rate. Related Articles | Metrics

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Trabecular metal tantalum rod implantation for avascular necrosis of the femoral head at pre-collapse stage Wang Zhi, Zhang Zhong-jie, Chen Ge, Li Zhong 2010, 14 (52):  9853-9856.  doi: 10.3969/j.issn.1673-8225.2010. 52.041 Abstract ( 264 )   PDF (312KB) ( 353 )   Save BACKGROUND: Trabecular metal tantalum rod implantation is a novel treatment for patients with avascular necrosis of the femoral head at pre-collapse stage. OBJECTIVE: To investigate the clinical efficacy of trabecular metal tantalum rod implanted for avascular necrosis of the femoral head at pre-collapse stage and the radiology outcomes of necrotic femoral head. METHODS: From March 2008 to August 2009, 7 patients with avascular necrosis of the femoral head at Association Research Circulation Osseous stage I and stage II were treated by trabecular metal tantalum rod implant. Harris score, X-ray and MRI were performed pre- and post-operatively. Necrotic tissue obtained by surgery was subjected to pathology. Antibiotics were applied for 3 days postoperatively, and affected limbs should avoid full weight-bearing in 3 months. RESULTS AND CONCLUSION: All incisions healed at primary stage with no infection or other postoperative complications. All 7 cases were followed up for 6-13 months. After tantalum rod implantation, the pain symptom of all cases mitigated significantly. The Harris score was 72.6±2.9 at 2 weeks and 81.3±3.5 at 10 months postoperation, showing a significant difference compared with preoperative score (65.4±3.1, P < 0.05). Postoperative X-ray showed that all 7 tantalum rods were well placed. Necrosis of the femoral head in 6 patients did not progress. One case presented with collapse at 4 months after surgery, but collapse did not increase at 8-12 months with sustained pain relief. Trabecular metal tantalum rod implantation can effectively delay the progression of avascular necrosis of the femoral head, relieve pain and improve functionality of affected hip. Collapse can also occur at prosthetic implanted femoral head but at a less extent and tends to stop. This may be related to the location of rod and the extent of femoral head necrosis. Related Articles | Metrics

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Proximal femoral nail anti-rotation blade for elderly osteoporotic femoral intertrochanteric fracture Zhu Jian 2010, 14 (52):  9857-9860.  doi: 10.3969/j.issn.1673-8225.2010. 52.042 Abstract ( 239 )   PDF (276KB) ( 449 )   Save BACKGROUND: The axis under stress of proximal femoral nail anti-rotation blade (PFNA) is inward shifted compared with dynamic hip screw (DHS), dynamic condylar screw (DCS), thereby increasing resistance to fatigue, with the support and the prevention of anti-varus rotation and thus less demanding on the stability of fractures. It has been used in unstable fracture. OBJECTIVE: To evaluate the effect of PFNA in the treatment of the elderly osteoporotic femoral intertrochanteric fracture. METHODS: A total of 44 cases of femoral intertrochanteric fracture treated by PFNA were retrospectively analyzed, including 20 males and 24 females aged 63-86 years. According to the Evans-Jensen classification, there were 3 cases of type Ⅱ, 8 of type Ⅲ, 10 of type Ⅳ, and 23 of type Ⅴ. The patients were followed up for 12 months. The incidence of postoperative complications, healing time and functional score were recorded. RESULTS AND CONCLUSION: All the 44 patients obtained fracture healing in average of 5 months. No complications such as proximal femoral refracture, femoral head avascular necrosis, or stub nail, were detected, except for two cases of coax vara due to the early time weight-load. According to Harris hip score, the excellent and good rate was 96%. Results show that PFNA is an effective therapy for femoral intertrochanteric fracture, especially for comminuted fractures or the aged osteoporosis fractures. It has some advantages, minimal invasion, simple operation, solid internal fixation, and little bone loss. Related Articles | Metrics

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PHILOS and locking proximal humerus plate for fractures of the proximal humerus Huang Lei, Li Guang-xu, Li Bo, Fu Jie, Zou Zheng 2010, 14 (52):  9861-9864.  doi: 10.3969/j.issn.1673-8225.2010. 52.043 Abstract ( 306 )   PDF (254KB) ( 378 )   Save BACKGROUND: PHILOS locking compression plate and locking proximal humerus plate (LPHP) are plates of new generation that are designed by international society of internal fixation according to the concept of biological osteosynthesis and local anatomic features of the humerus and biomechanical properties. OBJECTIVE: To compare the clinical effect of open reduction and internal fixation for the fractures of proximal humerus with PHILOS and LPHP blade plate. METHODS: A total of 49 cases of fractures of proximal humerus were randomly divided into two groups (PHILOS, n=24, 3 parts in 13 cases and 4 parts in 11 cases; LPHP, n=25, 3 parts in 15 cases and 4 parts in 10 cases) according to different implanted plates. All the cases were operated via deltoid-pectoral approach, and Neer numerical rating system was employed to evaluated postoperative function of the involved shoulders. RESULTS AND CONCLUSION: The 22 cases in PHILOS group and 23 cases in LPHP group were followed up for a mean time of (15.6±4.8) months. A total of 16 cases in PHILOS group and 18 cases in LPHP group obtained a bone union recover within 3 months and 21 cases in PHILOS group and 21 cases in LPHP group within 6 months, and all within 1 year. According to the Neer numerical rating system, 9 patients in PHILOS group showed a excellent result, 11 satisfactory, with an excellent and good rate of 90.9％; 10 patients in LPHP group showed a excellent result, and 11 satisfactory with an excellent and good rate of 91.3％. The treatment for fractures of proximal humerus with PHILOS and LPHP blade plate, which has been approved to be an excellent internal fixation, is able to get a good clinical result, such as stable fixation, few complications and high satisfactory rate. If combined with diaphyseal humerus, PHILOS blade plate is better. Related Articles | Metrics

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Expandable intramedullary nail for humeral shaft fractures in 33 cases Su Yan, Zhang Chang-qing, Cai Pei-hua, Chen Dong, Zeng Bing-fang 2010, 14 (52):  9865-9868.  doi: 10.3969/j.issn.1673-8225.2010. 52.044 Abstract ( 244 )   PDF (302KB) ( 409 )   Save BACKGROUND: Interlocking intramedullary nail has become gold standard for humeral shaft fractures. However, individual medullary cavity requires cavity expanding before inserting nail, which damages blood supply, reduces bone density and increases risk for fat embolism. OBJECTIVE: To evaluate the efficacy of expandable intramedullary nail for humeral shaft fractures. METHODS: From January 2005 to December 2009, 33 cases of humeral fracture were treated by expandable intramedullary nail. There were 20 cases of close reduction, 12 of limited open reduction and 1 of open reduction. The expandible intramedullary nails were inserted through antegrade approach. After 48 hours of nail insertion, adjacent joints moved under protection of forearm mitella.Constant score was used to evaluate function based on shoulder function, range of motion, and pain degree. RESULTS AND CONCLUSION: All patients were followed up for 7.8 months (range 4 to 12 months). All cases obtained bone union and the mean union period was 12.5 weeks (range 10 to 15 weeks). According to Constant’s functional and radiological scoring system, 20 were evaluated as excellent, 9 as good, 3 as fair and 1 was poor. The rate of excellent and good results was 87.88%. No infection, nail breakage, fat embolism, nonunion or malunion occurred. The humeral shaft fractures can be treated with expandable intramedullary nail, which offers enough stability, less invasion, simple manipulation and few complications. Related Articles | Metrics

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Application of computer-aided technique in pelvic precise model preparation and individualized prosthesis implantation Zhang Tao, Zhang Yu, Xu Liang, Yin Qing-shui, Huang Hua-yang, Wang Qing 2010, 14 (52):  9869-9872.  doi: 10.3969/j.issn.1673-8225.2009.52.045 Abstract ( 331 )   PDF (299KB) ( 270 )   Save BACKGROUND: Bone tumors around the Ⅱ section of pelvis are difficult to treat due to complicated anatomic structures. Using computer-aided technique, the excision range and prosthesis preparation can be individualized, which may obtain notable therapeutic efficacy in treating pelvic fractures in the clinic. OBJECTIVE: To discuss the application and the clinic effect of computer-aided technique in bone tumors therapy around the Ⅱ section of pelvis. METHODS: The pelvis model was generated with its CT data by rapid prototyping. Simulated bone resection and reconstruction were performed on the models. Then we designed surgical extension and made hemi-pelvic. Eight cases received resection of pelvic tumor and reconstruction based on computer-aided technique.  RESULTS AND CONCLUSION: The resection of tumor and implantation of prosthesis were easily accessible. Two cases relapsed and 1 case loosened at 2 years after operation. According to Harris scoring criteria after total hip replacement, the scores of cases were well. The simulated resection and reconstruction of bone tumors around the Ⅱ section of pelvis based on computer-aided technique makes the operation easy and reconstruction precise, which produces good clinic results and offers a good promise for the application. Related Articles | Metrics

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Distribution features of stress-strain, principle stress vectors and displacements of normal femur during gait Bai Xue-ling, Shang Peng, Wang Cheng-tao 2010, 14 (52):  9873-9876.  doi: 10.3969/j.issn.1673-8225.2010. 52.046 Abstract ( 384 )   PDF (305KB) ( 353 )   Save BACKGROUND: Studies demonstrated that, the probability of middle and distal end of femur bone fatigue or fracture reaches maximum when the moving loads increase or under an impact load. OBJECTIVE: To analyze the stress-strain distribution, principle stress vectors and displacements of femur during gait. METHODS: The contour curves of femur and muscles attached to femur were extracted slice by slice based on the serial CT data from a healthy male volunteer, which were used to build musculoskeletal system models. And the straight-line muscle models of the lower extremities were constructed to evaluate muscles forces and joints forces by using a multi-objective optimization method based on gait analysis. The finite element models of femur during gait were built by taking muscle forces and joint forces as boundary conditions in ANSYS 10.0 to obtain the stress-strain distribution and displacements. RESULTS AND CONCLUSION: The maximal displacement occurred on the femur head, and the maximal stress occurred in the middle and distal end of femur during the whole gait. There exists bigger tensile stress in the location of the femur neck and middle and distal end of corpus ossis femoris. The result validates the fact that femur fracture often happens at the middle and below of femur stem from the viewpoint of biomechanics. Related Articles | Metrics

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Central arterial augmentation index in Uygur health adults from Hetian, Xinjiang Detection by Sphygmocor pulse wave analysis system Liang Xiao-hui, Xu Xin-juan, Ma Yan-ping, Sun Li-hua, Ma Yi-tong, Huang Ding, Yang Yi-ning 2010, 14 (52):  9877-9880.  doi: 10.3969/j.issn.1673-8225.2010.52.047 Abstract ( 250 )   PDF (283KB) ( 325 )   Save BACKGROUND: Arterial stiffness is an independent risk factor for cardiovascular disease. Augmentation index (AIx) is an important marker which reflects the systemic arterial stiffness. OBJECTIVE: To investigate AIx and the affecting factors in Xinjiang Uygur health adults. METHODS: A total of 559 healthy adults (251 males and 308 females) with a mean age of (44.95±11.87) years were selected from Hetian, Xinjiang Uygur Autonomous Region. The following indexes of all subjects were measured, including questionnaire, physical examination, blood biochemistry and C-reactive protein (CRP). Central systolic blood pressure (cSBP) and central AIx were measured by Sphygmocor. Pearson correlation and partial correlation analysis were used for two-group analysis of correlation, and multiple regression analysis was used to analyze influential factors for AIx. RESULTS AND CONCULUSION: AIx was greater in female than in male and was positively related to age in both sexes (male: r=0.548, female: r =0.405, P < 0.05), as well as adjusted other influential factors (male: r=0.182, female: r =0.234, P < 0.05). Multiple regression analysis showed that cSBP, systolic blood pressure (SBP), sex, age and CRP were main factors which affected AIx in Uygur healthy adults. cSBP, SBP, age, body mass and CRP were main factors which affected AIx in the male, while cSBP, SBP, age, height and CRP were main factors which affected AIx in the female. Results revealed that AIx was greater in female than in male which was positively related to age in both sexes. Age, cSBP, SBP and CRP were main factors that affected AIx in Xinjiang Uygur healthy adults. Related Articles | Metrics