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1.
目的运用有限元分析方法,对正常及发育性髋关节发育不良(DDH)儿童股骨头近端骨骺生长板同承力情况下横断面的应力进行研究,为股骨近端截骨矫形手术提供理论依据。方法按照Tonnis分型选取40例DDH大龄儿童,其中男性11例,女性29例;年龄8~12岁,平均年龄10.14岁。分为半脱位及全脱位组。20例非DDH儿童作为正常对照组,其中男性11例,女性9例;年龄8~12岁,平均年龄10.10岁。通过二维CT技术测定各组股骨颈前倾角,通过有限元分析软件分析股骨头近端骨骺生长板在横断面上的应力情况。结果正常对照组股骨头近端骨骺生长板横断面上前内侧及后外侧的切应力和静压力相当。半脱位组及全脱位组股骨头近端骨骺生长板横断面上前内侧静压力大于后外侧,而前内侧的切应力小于后外侧。股骨颈前倾角与前后两侧静压力差呈正相关,与前后两侧切应力差呈负相关。结论 DDH大龄儿童的股骨颈前倾角随生长发育而增大。传统的股骨近端旋转截骨术在纠正发育性髋脱位儿童股骨骨骺异常应力,保证正常的头臼关系中有重要的临床意义。  相似文献   

2.
朱求亮  许斌 《解剖学报》2016,47(5):658-662
目的探讨肉眼直观下描述股骨颈扭转角及前倾角的区别,并分析其差异的临床意义。方法在股骨冠状面平面,分别从6点钟、12点钟、1∶30点钟、3点钟和4∶30点钟位置观察干燥完整的股骨标本(60根),在照片上分别确定股骨头颈轴线、股骨冠状面、股骨颈截面最长径及股骨上段冠状面,画图描述股骨颈扭转角与前倾角,分析这两个角度的区别。结果股骨颈前倾角是股骨头颈轴线与股骨冠状面的夹角,是线与面的关系,角尖朝内,在6点钟、12点钟、1∶30点钟、3点钟和4∶30点钟位均可观察到;股骨颈扭转角是股骨颈椭圆截面最长径线构成的面与股骨(上段)冠状面的夹角,是面与面的关系,角尖朝后,仅在12点钟、1∶30点钟、3点钟位可以观察到。1∶30钟位是显示股骨颈扭转角和前倾角区别的最佳位置。结论股骨颈前倾角和扭转角是共同基于股骨冠状面,分别与股骨头颈轴线、股骨颈截面最长径线构成的面,组成的两个不同角度参数。非立体观察是混淆股骨颈扭转角与前倾角的重要原因。前倾角决定内固定螺钉及股骨假体的方向,扭转角对内固定螺钉进钉点及股骨髓腔开口位置有参考价值。  相似文献   

3.
This study presents a new method of using computerized tomography images combined with the reverse engineering technique to obtain and analyse the three-dimensional inner and outer geometry of the proximal cadaveric femur. Three-dimensional models were reconstructed from the computerized tomography images and approximated with 2D and 3D fitting algorithms based on reverse engineering methods. The following parameters were calculated for each femur: femoral head diameter, femoral neck axis, femoral shaft axis, anteversion angle and neck-shaft angle. These data represent the geometry of the studied proximal femur, and can be used for the design of proper size and shape of femoral prostheses and trochanteric nail systems.  相似文献   

4.
In this paper, we introduce the concept of functional anteversion of the femur and its positional change. It emerged from studies using B-mode and real-time ultrasound to determine femoral anteversion in two knee positions. Twenty healthy children were scanned at the hips whilst lying supine with knees extended and then with the knees flexed to about 90°. The “anteversion” angle between the head-trochanter line and the horizontal measured with knees extended and feet together is determined by three factors: 1) anatomical femoral anteversion, 2) femoro-tibial rotation at the knee, and 3) tibial torsion. This is one type of “functional anteversion” of the femur. The best reproducibility for functional femoral anteversion was obtained by scanning with real-time ultrasound and the knees extended (95% confidence limits within ± 2.8°); the use of B-mode ultrasound in the knees-extended position is significantly less reproducible (95% confidence limits within ± 6.1°). In the flexed-knee position, the reproducibility is similar with both B-mode and real-time ultrasound (± 2.6–3.5°). Both positions have limitations in attempts to measure anatomical femoral anteversion by ultrasound. The functional femoral anteversion angle measured by B-mode and real-time ultrasound is significantly larger (by 9–10°) with the knees flexed than with the knees extended. This positional change of measured femoral anteversion involving axial rotation at the hip is attributed mainly to 1) lateral rotation (unlocking) of the femur at the knee during flexion from the fully extended position and 2) any lateral tibial torsion which rotates the femur nedially in the knees-extended position with the feet vertical. The considerable individual variation and asymmetry of this axial rotational change may have relevance to the etiology of certain clinical disorders of the spine, hip, and knee joints. © 1993 Wiley-Liss, Inc.  相似文献   

5.
PURPOSE: Past classification for the treatment of idiopathic genu vara depended simply on the measurement of distance between the knees, without attention to the rotational profile of the lower extremity. We retrospectively analyzed anatomical causes of idiopathic genu vara. PATIENTS AND METHODS: Twenty eight patients with idiopathic genu vara were included in this study. All patients were surgically treated. To evaluate the angular deformity, a standing orthoroentgenogram was taken and the lateral distal femoral angle and the medial proximal tibial angle were measured. In order to assess any accompanying torsional deformity, both femoral anteversion and tibial external rotation were measured using computerized tomographic scans. A derotational osteotomy was performed at the femur or tibia to correct rotational deformity, and a correctional osteotomy was performed at the tibia to correct angular deformity. RESULTS: Satisfactory functional results were obtained in all cases. Genu vara was divided into 3 groups according to the nature of the deformity; group 1 (6 patients) with increased femoral anteversion, group 2 (10 patients) with proximal tibial varus deformity alone, and group 3 (12 patients) with proximal tibial varus deformity accompanied by increased external tibial rotation. CONCLUSION: The success seen in our cases highlights the importance of an accurate preoperative analysis that accounts for both rotational and angular deformities that may underlie idiopathic genu vara.  相似文献   

6.
If metallic material is exposed to ionizing radiation of sufficient high energy, an increase in dose due to backscatter radiation occurs in front of this material. Our purpose in this study was to quantify these doses at variable distances between scattering materials and the detector at axial beam angles between 0 degree (zero angle in beams eye view) and 90 degrees. Copper, silver and lead sheets embedded in a phantom of perspex were exposed to 10 MV-bremsstrahlung. The detector we developed is based on the fluorescence property of pyromellitic acid (1,2,4,5 benzenetetracarboxylic acid) after exposure to ionizing radiation. Our results show that the additional doses and the corresponding dose distribution in front of the scattering materials depend quantitatively and qualitatively on the beam angle. The backscatter dose increases with varying beam angle from 0 degree to 90 degrees up to a maximum at 55 degrees for copper and silver. At angles of 0 degree and 55 degrees the integral backscatter doses over a tissue-equivalent depth of 2 mm are 11.2% and 21.6% for copper and 24% and 28% for silver, respectively. In contrast, in front of lead there are no obvious differences of the measured backscatter doses at angles between 0 degree and 55 degrees. With a further increase of the beam angle from 55 degrees to 90 degrees the backscatter dose decreases steeply for all three materials. In front of copper a markedly lower penetrating depth of the backscattered electrons was found for an angle of 0 degree compared to 55 degrees. This dependence from the beam angle was less pronounced in front of silver and not detectable in front of lead. In conclusion, the dependence of the backscatter dose from the angle between axial beam and scattering material must be considered, as higher scattering doses have to be considered than previously expected. This may have a clinical impact since the surface of metallic implants is usually curved.  相似文献   

7.
Numerous studies of the bicondylar angle of the adult femur have been carried out in human anatomy, paleoanthropology and primatology. The aim of this paper is to study the evolution of this angle in relation to age and acquisition of walking in young children. Seventy-seven radiographs of children, ranging from 5 months to 17 years postnatally, and of four dead newborn were analysed. The measurements concern the bicondylar angle (A.O.F.), the collo-diaphyseal angle (A.C.D.), the length of the femoral neck (L.N.) and of the femur (L.F.) and the interacetabular distance (D.I.A.). Some children were x-rayed at different ages, which permits a longitudinal as well cross-sectional study. The results show that there is no sexual dimorphism and that the increase in the angle is closely related to the age of the child. The bicondylar angle starts at 0° at birth and then increases progressively with growth to reach adult values of at least 6°-8° between 4 and 8 years postnatally. In adults, the mean values are between 8° and 11° and the maximum range is between 6° and 14°. The obliquity angle corresponds to an angular remodeling of the femoral diaphysis, which is independant of the growth and shape of the distal femoral epiphysis. The tibio-femoral angle measures the evolution of a physiologic phenomenon, from the load “in varus” to the load “in valgus” of the lower limb. It is linked with the bicondylar angle but is different from it.  相似文献   

8.
In this study we describe the development of the female femur based on the analysis of high‐resolution radiographic images by means of geometric morphometrics, while assessing the usefulness of this method in these kinds of studies. The material analysed consisted of digital images in DICOM format (telemetries), corresponding to 184 left femora in anterior view, obtained from the database of the Hospital Sant Joan de Déu of Barcelona (Spain). Bones analysed corresponded to individuals from 9 to 14 years old. Size and shape variation of the entire femur was quantified by 22 two‐dimensional landmarks. Landmark digitisation errors were assessed using Procrustes anova test. Centroid size (CS) variation with age was evaluated by an anova test. Shape variation was assessed by principal component analysis. A mancova test between the first five principal components and age, using the CS as covariable, was applied. Results indicated that both size and shape vary significantly with age. Several age‐related shape changes remained significant after removing the allometric effect. In general, an increase in the robustness of the bone and noticeable phenotypic changes in certain areas of the femur were observed. During growth in the proximal region of the femur, the collo‐diaphyseal angle decreases, the neck of the femur widens and the fovea moves to a lower position, standing more in line with the plane of the neck. Likewise, the size of the greater and lesser trochanters increase. In the distal region, a significant increase of epiphyseal dimensions was recorded, mainly in the medial condyle. The angular remodelling of the neck and the bicondylar region of the femur in females continues until 13 years old. The information provided in the present study increases our knowledge on the timing and morphology of the femur during development, and in particular the morphology of the different femoral ossification centres during development.  相似文献   

9.
A Nejidat  R N Beachy 《Virology》1989,173(2):531-538
Transgenic tobacco plants that accumulate tobacco mosaic virus (TMV) coat protein (CP) are resistant to TMV infection under standard growth conditions. The amount of CP accumulated and the degree of resistance to TMV were found to be temperature dependent. Exposure to continuous high temperatures (30-35 degrees) results in a sharp decrease in the amount of CP within 6 hr with no further change for at least 6 days. Under these conditions the transgenic plants developed typical systemic disease symptoms when inoculated with TMV although disease development was delayed. Transgenic plants which were moved from 35 to 22 degrees accumulated the normal level of CP within several hours. Transgenic tobacco plants inoculated and held at 35/25 degrees day/night cycles retained resistance to TMV infection. The level of CP mRNA was constant at each temperature and was associated with polyribosomes. On the basis of these results we suggest that the low level of CP under elevated temperature is due to instability of the TMV CP. In contrast, TMV CP levels in transgenic tomato plants also dropped under elevated temperatures yet retained high resistance to TMV.  相似文献   

10.
目的 对比年龄≥30岁伴股骨前倾角异常增大(>40°)髋关节发育不良患者(developmental dysplasia of the hip, DDH)接受髋臼周围截骨术(periacetabular osteotomy, PAO)联合股骨近端去旋转截骨术(derotational osteotomy, PFDO)与单纯PAO的手术效果。方法 选取2012年1月至2020年1月在解放军总医院第四医学中心骨科医学部接受PAO联合PFDO的年龄≥30岁伴股骨前倾角异常增大(>40°)的DDH患者,共计55例,按照接受手术方式不同,分为联合手术组(n=29)和PAO组(n=26)。联合手术组接受PAO联合PFDO治疗,PAO组仅接受PAO治疗。比较两组患者的LCEA、ACEA、Tönnis角术前及术后1年的差异,比较两组患者术前、术后6个月、术后1年及末次随访(>2年)的改良Harris评分和iHot-12评分。结果 共计随访55例患者,随访时间为2年1个月 ~ 9年11个月。术后6个月,联合手术组与PAO组的改良Harris评分和iHot-12评分相近(P>0.05)。术后1年及末次随访(>2年)的改良Harris评分和iHot-12评分,联合手术组优于PAO组(P<0.05)。结论 对于年龄≥30岁伴股骨前倾角异常增大(>40°)的髋关节发育不良患者而言,PAO联合PFDO手术效果优于单纯PAO手术。  相似文献   

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