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Objective To establish the three-dimensional finite element model of lumbar spine(L) 3-5 segments of the normal spine of 14-year-old adolescents to analyze the biomechanical changes of the lumbar spine after different degrees of lumbar foraminal plasty, and to provide reference for improvement of adolescent foraminoplasty. Methods A14-year-old female volunteer with no previous history of lumbar spine was selected to collect lumbar CT image data and we imported it into Mimics 16.0 software for modeling. ABAQUS software was used to conduct finite element model force analysis. Models M
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Objective To investigate the effect of facet joint asymmetry on lumbar biomechanics in normal and patients with adolescent lumbar disc hemiation (ALDH). Methods Mimics 21.0, 3-Matic Medical 13.0, Geomagic Wrap 2017, HyperMesh 2019 and finite element software ABAQUS 2021 were combined to establish three-dimensional finite element models of nonnal lower lumbar spine and adolescent lumbar disc hemiation. According to the difference between the left and right facet joints, three cases of nonnal and ALDH patients aged 13-18 years old were selected, with a total of 6 cases. The stress of intervertebral disc under different torque loads (neutral position, lateral flexion and rotation) was analyzed and compared. Results 1. Three dimensional finite element models of L3-L, segments were established in 6 male nonnal and adolescent patients with lumbar disc herniation, and the stress and displacement nephogram of lumbar disc hemiation in nonnal neutral position, flexion, extension, lateral flexion and rotation were obtained; 2. The stress of L4_, annulus fibrosus increased when the facet joint angle of nonnal adolescents was symmetrical in the neutral position; 3. The stress of annulus fibrosus was greater than that of nucleus pulposus under different conditions, and the stress of annulus fibrosus was flexion > neutral position > extension; 4. In patients with ALDH, the left side of the facet joint was larger than the right 10 ° model, and the stress in the posterior side of the annulus fibrosus of L4_, segment increased significantly under extension condition. Under lateral flexion condition, the left stress of the left annulus fibrosus was compared with the right stress of the right annulus fibrosus, t = l. 575, P<0. 05, the difference was statistically significant, the right stress of the right annulus fibrosus was greater than the left stress of the left annulus fibrosus. Under the rotating condition, the stress on the left and right sides of the fiber ring was greater than that on the back side. Conclusion 1. Compared with nonnal and patients with ALDH, the stress of intervertebral disc increases under different postures, which ma)' increase the shear load of intervertebral disc and aggravate the process of intervertebral disc degeneration; 2. When the degree of left-right asymmetry of facet joint is more than 10 degrees, the stress on the side with small degree is greater. Facet joint asymmetry can lead to the overload of vertebral bod)' and intervertebral disc, leading to spinal instability; 3. The stress of intervertebral disc in extension is less than that in neutral position and flexion. Extension can relieve the pressure of intervertebral disc and play an auxiliary role in the recovery of patients with ALDH.
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Objective To measure the anatomical structure of the occipital condyle (OC) and the occipital foramen (FM) by three-dimensional reconstruction, and to analyze the morphological characteristics and relative positional relationship of the occipital condyle and occipital foramen, in order to provide anatomical parameters for the imaging diagnosis of the craniocervical junction and the choice of surgical approach. Methods Sixty normal subjects were selected with CT scans of the skull and upper cervical spine, including 30 males and 30 females, aged 20-65 (48. 18±16. 17) years old. The data were imported into the Syngo.via VB10B software, and the skull was reconstructed in three dimensions. To observe the shape of the occipital condyle and occipital foramen, and to measure the occipital condyle length, width, height, condyle inclination angle(CIA), longitudinal diameter, transverse diameter, area of the occipital foramen, the maximum distance between the cranial eyebrow and the posterior cranial point (SML), the crimson eyebrow on the SML line, the distance from the interpoint to the posterior margin of the occipital condyle (GOCP), the vertical distance between the anterior edge of the occipital foramen to the posterior margin of the occipital condyle (AOCP), and the distance from the medial margin of the left and right occipital condyles to the Y axis (OC-M), left and right occipital condyle posterior margin to X axis distance (OC-P); occipital condyle classification index (OCI), occipital condyle relative index of head (SOCI), midpoint on the SML straight line to the occipital condyle Marginal connection distance (COCP,COCP =GOCP-SML/ 2), and determine the type of relative positional relationship between left and right occipital condyles. Results The differences in anatomical length, width and height of the occipital condyle were statistically significant (P<0. 05), and men were larger than women; the occipital foramen area, longitudinal diameter of the occipital foramen, SML, GOCP, AOCP had statistical differences (P<0. 05). The lateral differences of occipital condyle inclination were statistically significant (P<0. 05), and the left side was greater than the right side. The differences in OC-M and OC-P sides were statistically significant (P<0. 05). The former was larger on the right than on the left; the latter was larger on the left than on the right. The longitudinal diameter of the occipital foramen was positively correlated with the area of the occipital foramen and AOCP; OCI classification result were as follows: typeⅠ(OCI<0. 45) had 8 cases (13. 33%), type Ⅱ (0. 45≤OCI<0. 50) had 47 cases (78. 33%), type Ⅲ (OCI≥0. 50) had 5 cases (8. 33%). SOCI classification result were as follows: type Ⅰ (SOCI< 0. 60) had 2 cases (3. 33%), type Ⅱ (0. 60≤SOCI<0. 75) had 54 cases (90. 00%), type Ⅲ (SOCI≥0. 75) had 4 cases (6. 67%). Conclusion The anatomical parameters of the occipital condyle in Inner Mongolia can be implanted with occipital condylar screws. The position of the occipital condyle relative to the foramen magnum and the skull is highly variable.
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BACKGROUND: Acetabulum anterior column shape is complex, and closed to femoral artery, and femoral nerve. Fixed screws easily went into the acetabulum. Currently, there was less data on quantitative anatomy data of pelvic acetabulum fracture with anterior column plate internal fixation. OBJECTIVE: To compare the pelvis gender differences by analyzing digital anatomical features of normal adult acetabulum anterior column section through digital three-dimensional reconstruction and measurement. METHODS: Totally 30 normal adults (half male and half female) received pelvic CT scans, and data were obtained. Using Materialise Mimics Innovation Suite 16.0 software, the boundary of the pelvis was used as reference line for sectioning. The obturator groove, iliopubic eminence, anterior inferior iliac spine, and the anterior superior iliac spine were used as a reference mark. In 15 males and 15 females (30 sides), the corresponding boundary line from obturator groove to the anterior superior iliac spine of acetabular anterior column was sliced into 5 mm-thick sections. The tangent line was vertical to the boundary line. The tangent plane was vertical to the upper plane of the anterior column. The angle and length of each section 5, 10, 15 mm points from the boundary line to the acetabulum, and the perpendicular distance from anterior and posterior edges of the acetabulum to anterior inferior iliac spine, iliopubic eminence and the pubic tubercle. RESULTS AND CONCLUSION: (1) Acetabular anterior column from the obturator groove to the anterior superior iliac spine section was not significantly different (P > 0.05). (2) No matter in males or females, the tangent angle of the fifth layer section was minimum, and the tangent length of the sixth layer section was longest. The length and angle of the second slice at 5 mm point were not significantly different between males and females. However, above indexes in others were significantly larger in females than in males (P < 0.05). (3) Results indicated that in different fracture ranges and different fixation plate positions, the angle and length of pedicle screws are dynamic, so we only selected in accordance with above range, but cannot fix in a certain value. The design of the most accurate and effective placement angle and length should be aimed at nailing design parameters for each individual patient. The use of Mimics software can be used for three-dimensional reconstruction of CT data of adult acetabular anterior column fracture, and can measure the number of indexes, and provide a theoretical reference for the clinical diagnosis and treatment of acetabular anterior column fracture.
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Objective: To investigate the effect of hypertension on the process of carotid atherosclerotic lesions in patients with type 2 diabetes mellitus using ultrasound techniques. Methods: A total of 203 consecutive type 2 diabetic patients with hypertension were enrolled into the study. The patients were grouped according to the increased systolic blood pressure for 5 mm Hg as an observation unit. The hemodynamic parameters of intracranial and extracranial arteries in each group were measured by using color Doppler flow imaging (CDFI) and transcranial Doppler ultrasound (TCD) to identify the extent of vascular lesions. The correlations of systolic and diastolic blood pressure, age, hypertension, duration of diabetes with the detection rate of common carotid intimal medial thickness (CCA-IMT), carotid and intracranial arterial stenosis were analyzed. Results: Circled digit oneThe CCA-IMT in 203 patients was 0.62-1.36 mm (mean 1.04 ± 0.14 mm). The detection rate of intracranial arterial stenosis was 52.7%, in which the detection rate of stenosis rate ≥ 50% was 21.2%; the detection rate of extracranial carotid artery stenosis was 28.1%, in which the detection rate of stenosis rate ≥ 50% was 14.8%. The total detection rate of intracranial arterial stenosis and the detection rate of stenosis rate ≥ 50% were higher than extracranial carotid artery, in which there were significant differences in total detection rate of stenosis (P 0.05). Circled digit twoMultiple stepwise regression analysis showed that there was a linear relationship between the CCA-IMT and systolic blood pressure and age. For each increase of 5 mm Hg in systolic blood pressure, the CCA-IMT would increase 0.015 mm; for each increase of 1 year of age, the CCA-IMT would increase 0.008 mm. Circled digit threeThe total detection rate of intracranial artery stenosis showed a linear relationship with age. For each increase of 1 year of age, the total detection rate of stenosis increased 2.8%; the detection rate of ≥ 50% stenosis showed a linear relationship with systolic blood pressure. For each increase of 5 mm Hg in systolic blood pressure, the detection rate of stenosis increased 2%. Conclusion: the CCA-IMT increases with the increased blood pressure in hypertensive patients with type 2 diabetes. The progression of intracranial arterial stenosis in patients with diabetes mellitus promoted by hypertension is more apparent than carotid artery.