Growth characteristics of the fetal ligament of the head of femur: significance in congenital hip disease.

Measurement of the length and width of the ligament of the head of femur (ligamentum teres) in 140 normal human fetuses between 12 weeks and term provides limits for growth changes in this structure. These observations provide no morphological evidence of a significant difference between males and females, or between the right and left sides, to explain the female and left hip preponderance reported in congenital hip disease. The ligament is shown to be variable in length, width, and shape, and it is not a distinctly linear structure through linearity may increase with age. Tests of femoral head mobility support the opinion that this ligament must play a role in fetal and neonatal hip joint stability. Weak correlation only was demonstrated between the ligament variables and acetabular depth, which suggests that ligament shape and socket shape are not closely related. Comparison of measurements from normal and 12 dysplastic or subluxated joints provides no evidence to support previous observations that this structure is unusually long in abnormal hip joints which are not frankly dislocated.     

Roentgenologic characteristics of small bronchoalveolar cancer of the lung under conditions of image processing using linear filtration (roentgenomorphologic comparison)

X-ray and morphological signs were compared in 50 patients with histologically verified bronchioloalveolar cancer (BAC). Particular attention was drawn to a study of an x-ray picture after computer processing of a tomographic image using a special technique. The most characteristic x-ray signs of BAC were subpleural localization, the presence of a fragmented scar in a tumor, and ill defined outlines. The peculiarities of an x-ray picture of small-size BAC were determined by the morphological structure of a tumor, a degree of its differentiation that could be detected in most cases only after image processing by the linear filtration technique.     

Arsenic content in the femur head of the residents of southern and central Poland

Arsenic content was assayed in the samples of the femur head of the people living in southern and central Poland (Kraków, n=13; Silesian region, n=13; Łódź, n=12). The average age being 68.7±8.7 yr. Arsenic content in the femur head was determined applying the hydride generation atomic absorption spectrometry (HG-AAS) method after microwave mineralization. The average arsenic contents in the femur head of the residents of the Łódź, Kraków, and Silesian regions were 0.41 μg/g, 0.37 μg/g, and 0.18 μg/g, respectively. No correlation has been found between arsenic content in the femur head and the content of other metals. Neither the age nor sex of the people tested affected the arsenic content in the femur head.     

Increase in the pace of the growth of the human fetus towards the end of pregnancy]

Growth velocity curves of 19 biometrical parameters were established from 490 normal fetuses or neonates, who died in the perinatal period, and from 4,507 ultrasound examinations. There was a velocity fall for numerous parameters during the third trimester of gestation, but growth rate started up again after 38 weeks for some of them (femur length, biparietal diameter, crown-rump length, head circumference ...). No acceleration was found for body weight and crown-heel length by the end of gestation.     

A comparative evaluation of the clinical x-ray picture of uremic osteodystrophy before and after parathyroidectomy]

The authors present the results of clinical, x-ray, and biochemical studies carried out in 51 patients with uremic osteodystrophy, treated with hemodialysis, before and after parathyroidectomy. The patients were divided into 4 groups with various patterns of x-ray symptoms. Patients with x-ray signs of fibrous osteodystrophy made up group 1, the second group consisted of patients with a combination of fibrous osteodystrophy and osteomalacia with secondary hyperparathyrosis predominance; the third group, like the second one, included patients with the mixed form of uremic osteodystrophy, but with the predominance of the osteomalacic syndrome; Group 4 patients had no x-ray signs of bone changes, and the diagnosis of uremic osteodystrophy was confirmed by clinical laboratory evidence. Analysis of the clinical and x-ray data before and after parathyroidectomy has brought the authors to a conclusion that such an intervention was effective only in cases with manifest clinical and x-ray symptoms of fibrous osteodystrophy. In Group 2 patients with the mixed form of uremic osteodystrophy and less manifest osteomalacia as against fibrous osteodystrophy, subtotal or partial parathyroidectomy is advisable only in cases when conservative therapy is of no avail and fibrous dystrophy is progressing. Surgical treatment is contraindicated to patients in whom x-ray signs of osteomalacia predominate over fibrous osteodystrophy in the total picture of uremic osteodystrophy; it may result in a rapid progress of osteomalacia.     

Trichomes of tobacco excrete zinc as zinc-substituted calcium carbonate and other zinc-containing compounds

Tobacco (Nicotiana tabacum L. cv Xanthi) plants were exposed to toxic levels of zinc (Zn). Zn exposure resulted in toxicity signs in plants, and these damages were partly reduced by a calcium (Ca) supplement. Confocal imaging of intracellular Zn using Zinquin showed that Zn was preferentially accumulated in trichomes. Exposure to Zn and Zn + Ca increased the trichome density and induced the production of Ca/Zn mineral grains on the head cells of trichomes. These grains were aggregates of submicrometer-sized crystals and poorly crystalline material and contained Ca as major element, along with subordinate amounts of Zn, manganese, potassium, chlorine, phosphorus, silicon, and magnesium. Micro x-ray diffraction revealed that the large majority of the grains were composed essentially of metal-substituted calcite (CaCO3). CaCO3 polymorphs (aragonite and vaterite) and CaC2O4 (Ca oxalate) mono- and dihydrate also were identified, either as an admixture to calcite or in separate grains. Some grains did not diffract, although they contained Ca, suggesting the presence of amorphous form of Ca. The presence of Zn-substituted calcite was confirmed by Zn K-edge micro-extended x-ray absorption fine structure spectroscopy. Zn bound to organic compounds and Zn-containing silica and phosphate were also identified by this technique. The proportion of Zn-substituted calcite relative to the other species increased with Ca exposure. The production of Zn-containing biogenic calcite and other Zn compounds through the trichomes is a novel mechanism involved in Zn detoxification. This study illustrates the potential of laterally resolved x-ray synchrotron radiation techniques to study biomineralization and metal homeostasis processes in plants.     

Errors and difficulties in the x-ray diagnosis of osteogenic sarcoma of the long tubular bones

In some cases radiodiagnosis of osteogenic sarcoma is associated with some difficulties resulting from a variety of its x-ray picture. The main factor that influences the x-ray manifestations of osteogenic sarcoma, is a neoplastic bone formation which reflects the morphological essence of this tumor. Other signs depend on a tumor site in one or another anatomical part of the tubular bone, on rates and type ot tumor growth. In some cases the combination of these signs ensures reliable diagnosis. However, along side with typical forms of osteogenic sarcoma there are also other ones which do not fit into the classical concept of this tumor type resulting in diagnostic difficulties and errors.     

Biomaterial-loaded allograft threaded cage for the treatment of femoral head osteonecrosis in a goat model

The purpose of this study was to evaluate the efficacy of core decompression with a biomaterial-loaded allograft threaded cage (ATC) for the treatment of femoral head osteonecrosis in an established goat model. First, bilateral early-stage osteonecrosis was induced. After core decompression, the remaining goats were randomly divided into three groups: Group A, the goats were left without any treatment; Group B, the goats were treated with implanting a composite of autologous bone and decalcified bone matrix (DBM); Group C, the goats were treated using insertion of ATC loaded with DBM and autogenous bone graft. Then radiographic, histological and biomechanical analysis were taken in each group at 5, 10, and 20 weeks postoperation. In Group A, the classical signs of osteonecrosis of the femoral head were identified 10 weeks after the induction. Twenty weeks later, the density, surface and biomechanical stability of the femoral head were normal in Group C, while an irregular surface and an inhomogeneous microstructure or variation of density/hardness were identified in Group B. The specimens revealed a continuous trabaecular bone structure throughout the cage and extensive bone ingrowth and remodeling in Group C, while fibrous tissue was evident in Group B. Core decompression with a biomaterial loaded ATC almost uniformly delays or arrests the progression of the disease before articular collapse, and it could help to get the balance between bone resorption and new bone formation, strengthen structural mechanics of the femoral head, provide structure support of articular cartilage.     

Stress changes in the femoral head due to porous ingrowth surface replacement arthroplasty

Finite element stress analyses were conducted of the canine femoral head before and after implantation of various surface replacement-type components. The femoral head was replaced by four implant geometries; (a) shell, (b) shell with peg, (c) shell with rod, and (d) a new epiphyseal replacement design. All implants were modelled to simulate bony ingrowth along the underside of the shell and along the surfaces of the peg and rod. The results indicated that in the normal femur the forces are transferred from the articular surface through the femoral head cancellous bone to the inferior cortical shell of the femoral neck. After shell-type surface replacement, forces were transferred more distally at the rim of the shell and at the end of the peg or rod, thereby reducing the stresses in the proximal head cancellous bone. Computer simulation of bone remodelling due to proximal bone stress reduction was shown to accentuate the abnormality of the stress fields. Surface replacement with a lower modulus material created a less abnormal redistribution of bone stresses. The new epiphyseal replacement design resulted in stress distributions similar to those in the normal femoral head and minimal shear stresses at the implant/bone interface. These findings suggest that the epiphyseal replacement concept may provide better initial mechanical integrity and create a more benign milieu for adaptive bone remodelling than conventional, shell-type surface replacement components.     

Loosening of cementless femoral stems: a biomechanical analysis of immediate fixation with loading vertical, femur horizontal

Large joint implants must have immediate fixation to be successful. Unfortunately, the magnitude and consistency of achieving this remains largely unknown. For cementless femoral components it is being increasingly appreciated that torsional loading as occurs during stair climbing or rising from a chair leads to loosening and thigh pain in some cases. A biomechanical test was developed to evaluate fixation in this position. Twelve pairs of human cadaveric femora were press-fit with an AML stem. Each femur was secured in a horizontal position, and the prosthetic head cyclically loaded in a vertically downward direction. The offset of the prosthetic head resulted in a combined torsional and compressive load being applied to the stem within the proximal femur. Loosening was found to consistently occur and rapidly accelerate when the head subsided more than 0.2 mm during 100 cycles. For the AML stem, loosening developed at loads from 62 to 171% of body weight and after as few as 800 cycles. This is within the physiologic range of normal daily activities as measured by others with instrumented prostheses. This poses a challenge to the ability of press-fit stems to tolerate torsional loads in vivo. Patients with a cementless prosthesis should be protected from torsional loading until porous ingrowth and/or bone remodelling have had time to occur. Testing the same stem in paired femora demonstrated no right vs left difference (p greater than 0.6).     

Comparison of radiologic and gross examination for detection of cancer in defleshed skeletons

The reliability of visual examination of defleshed bones was assessed for detection of postcranial metastatic disease in individuals known to have had cancer. This was compared with standard clinical radiologic techniques. The skeletons of 128 diagnosed cancer patients from an early 20th century autopsied skeletal collection (Hamann-Todd Collection) were examined. Radiologic examination detected evidence of metastatic disease in 33 individuals, compared to 11 by visual examination of the postcranial skeletons. Four of these cases were detected by both techniques. Blastic lesions were most commonly overlooked on visual examination, because they were localized to trabecular (internal bone) structures. The ilium was the most commonly affected bone, with lytic or blastic lesions detected in 30 of 33 individuals. While the proximal femur was affected in only nine individuals, x-ray of the proximal femur and ilium detected all individuals with postcranial evidence of metastatic disease. Skeletal distribution of metastases provides no clue to the location of origin or histologic subtype of the cancer. Survey of archeological human remains for metastatic cancer requires radiologic examination. Such skeletal surveys should x-ray at least the ilia and femora. © 1995 Wiley-Liss, Inc.     

Compression or tension? The stress distribution in the proximal femur

Background  

Questions regarding the distribution of stress in the proximal human femur have never been adequately resolved. Traditionally, by considering the femur in isolation, it has been believed that the effect of body weight on the projecting neck and head places the superior aspect of the neck in tension. A minority view has proposed that this region is in compression because of muscular forces pulling the femur into the pelvis. Little has been done to study stress distributions in the proximal femur. We hypothesise that under physiological loading the majority of the proximal femur is in compression and that the internal trabecular structure functions as an arch, transferring compressive stresses to the femoral shaft.     

X-ray characterization of changes of the lungs in juvenile rheumatoid arthritis

The results of chest x-ray were analyzed in 66 pediatric patients with juvenile rheumatoid arthritis (JRA). X-ray signs of pneumofibrosis were revealed in 37 (56%) patients. Besides, rare pulmonary changes (emphysema, rheumatic nodules, infiltrates) were detected in the JRA patients. The absence of clinical symptoms in the presence of x-ray changes necessitates the performance of chest x-ray in JRA for early detection of the pulmonary symptoms of this disease.     

Some anthropometric studies of the femur of the male West Malaysian Chinese

Measurements and indices were made on 120 male West Malaysian Chinese femora. The findings are compared with appropriate ones from some Eastern and Western series. The Chinese femur is smaller than all the other groups listed except for the Japanese femur. There is a high degree of significance between the maximum and bicondylar lengths of the Chinese femur against those of the Australian aborigine, Maori and White American. The head of the femur is greater in the Maori and White American than the Chinese. The platymeric index is nearly as high as the White American. The difference in the robusticity index of the femur between the Australian aborigine, Maori, White American and the present series is small. The collodiaphyseal angle of the Chinese femur is large being greater than the Australian aborigine, Finn and White American. The angle of torsion of 11.8° is within the range for Westerners with a high incidence of retroversion unlike the Australian aborigine and Maori where no retroversion is seen. Although most of the means of the measurements and indices of the femur show a highly significant difference between the present series and some of the other groups listed there is a wide overlap for measurements of the Chinese femur to be used for racial identification.     

Sensitivity analysis of hip joint centre estimation based on three-dimensional CT scans

In morphological analysis of the femur, the hip joint centre (HJC) is generally determined using a 3D model of the femoral head based on medical images. However, the portion of the image selected to represent the femoral head may influence the HJC. We determined if this influence invalidates the results of three HJC calculation methods, one of which we introduce here.

To isolate femoral heads in cadaver CT images, thresholds were applied to the distance between femur and acetabulum models. The sensitivity of the HJC to these thresholds and the differences between methods were quantified.

For thresholds between 6 and 9 mm and healthy hips, differences between methods were below 1 mm and all methods were insensitive to threshold changes. For higher thresholds, the fovea capitis femoris disturbed the HJC. In two deformed hips, the new method performed superiorly. We conclude that for normal hips all methods produce valid results.     

Sensitivity analysis of hip joint centre estimation based on three-dimensional CT scans

In morphological analysis of the femur, the hip joint centre (HJC) is generally determined using a 3D model of the femoral head based on medical images. However, the portion of the image selected to represent the femoral head may influence the HJC. We determined if this influence invalidates the results of three HJC calculation methods, one of which we introduce here. To isolate femoral heads in cadaver CT images, thresholds were applied to the distance between femur and acetabulum models. The sensitivity of the HJC to these thresholds and the differences between methods were quantified. For thresholds between 6 and 9?mm and healthy hips, differences between methods were below 1?mm and all methods were insensitive to threshold changes. For higher thresholds, the fovea capitis femoris disturbed the HJC. In two deformed hips, the new method performed superiorly. We conclude that for normal hips all methods produce valid results.     

Bending vibrations of the femur and the oscillatory behavior of a cemented femoral hip endoprosthesis

The paper presents a novel method for recording amplitude and phase of 6D-vibrations of a spatial pendulum over a wide frequency range (10 Hz up to 20 kHz). The six degrees of freedom of the pendulum mass were monitored by three electrodynamic stereo pickups. At rest, the tips of the needles and the pendulum's center of mass defined the reference system with respect to which the oscillations of the mass were recorded in terms of their amplitudes and phases. Its small dimensions, constant transfer characteristics, linearity, high dynamics, and virtual lack of reaction onto the moving system over the entire frequency range provided the advantages of the measuring system. This method was used to analyze the spatial 6D-vibrations of the head of a cemented femoral hip endoprosthesis when the femur was stimulated to bending vibrations. The head of the prosthesis carried out axial rotational vibrations at every frequency used to stimulate the femur. The amplitudes of the axial rotations of the cortical bone were small in comparison to the ones of the prosthesis head, indicating that axial rotational vibrations following femur bending vibrations mainly stressed the spongiosa and the cement layer. This was observed over the entire frequency range, including at the low frequencies relevant for gait. Over the low-frequency range, as well as at some of the higher resonance frequencies, stationary instantaneous helical axes characterized the vibrations. The measurements suggest the mechanism that the interface "implant-bone" may already be stressed by axial torsional loads when the femur is loaded by bending impacts that are known to occur during walking.     

散居型西藏飞蝗九个地理种群形态特征的数量分析

为阐明西藏飞蝗Locusta migratoria tibetensis Chen散居型地理种群数量性状的地理变异,将散居型西藏飞蝗9个地理种群雌、雄个体的前翅长度(E)、后足股节长度(F)、头宽(C)、前翅长度与后足股节长度比值(E/F)、后足股节长度与头宽比值(F/C)5项形态特征参数进行系统聚类分析和主成分分析....     

Cardiac involvement in central lung cancer

An x-ray picture of central lung cancer was analyzed in 34 operated patients in whom tumors had infiltrated the myocardium (left atrial infiltration in 33, right atrial infiltration in one, ventricular infiltration in 2). The comparison of x-ray findings with gross specimens of the removed lungs showed that tumor mass consisted of a primary tumor and metastatic bronchopulmonary lymph nodes that made impossible the differentiation of separate elements of the root x-ray image. Angiography was performed in 15 patients with suspected infiltration of the heart by a tumor on the basis of x-ray findings. Cardiac affection which was characterized on x-ray by change in the shape of the chambers, irregularity of their outlines or a filling defect at the site of tumor infiltration. Suspected cardiac infiltration by a tumor can be based on indirect x-ray signs: the presence of a large tumor mass in the area of the root, a shift of the deflated lung regions to the heart, the absence of an image of heart borders and pulmonary veins on tomograms, and a confluent image of the affected lung and cardiac shadow. These signs serve an indication for angiography.