Ultrastructure of the substantia spongiosa of the femur head and talus

The results of the SEM examination of the zone between the cartilage and the spongeous substances are described precisely. For the first time, W. Lierse examined the 'tensulae' of calcium-collagen lamellae by light microscopy. The examination of this zone was initiated by the fact that the hydrodynamic flow can take place in the calcified zone of the cartilage which is filled with synovial fluid and that the calcified zone adheres to the subchondral substantia corticalis. The subchondral corticalis is characterized by funnel-like indentations with a high number of calcium-collagen and chondrocyte 'tensulae' which are up to now uncounted. The special aim was to locate the separation of the space of adipose and arterial supplies.     

The importance of femur/acetabulum cartilage in the biomechanics of the intact hip: experimental and numerical assessment

Experimental studies have been made to study and validate the biomechanics of the pair femur/acetabulum considering both structures without the presence of cartilage. The main goal of this study was to validate a numerical model of the intact hip. Numerical and experimental models of the hip joint were developed with respect to the anatomical restrictions. Both iliac and femur bones were replicated based on composite replicas. Additionally, a thin layer of silicon rubber was used for the cartilage. A three-dimensional finite element model was developed and the boundary conditions of the models were applied according to the natural physiological constrains of the joint. The loads used in both models were used just for comparison purposes. The biomechanical behaviour of the models was assessed considering the maximum and minimum principal bone strains and von Mises stress. We analysed specific biomechanical parameters in the interior of the acetabular cavity and on femur's surface head to determine the role of the cartilage of the hip joint within the load transfer mechanism. The results of the study show that the stress observed in acetabular cavity was 8.3 to 9.2 MPa. When the cartilage is considered in the joint model, the absolute values of the maximum and minimum peak strains on the femur's head surface decrease simultaneously, and the strains are more uniformly distributed on both femur and iliac surfaces. With cartilage, the cortex strains increase in the medial side of the femur. We prove that finite element models of the intact hip joint can faithfully reproduce experimental models with a small difference of 7%.     

Ligament of the head of the femur in the orangutan and Indian elephant

A literature search revealed that for over 100 years there has been a consensus that the ligament of the head of the femur (LHF) is absent in the orangutan and elephant. A dissection of the hip joints of an adult orangutan and an adult Indian elephant exposed, in each joint, a robust LHF that is functionally important. These LHFs are easily overlooked during a cursory examination of the hip joints because of the way they differ from the human LHF.     

The stiffness of different sections of the cartilaginous surface of the femur head

As a result of investigations on microstiffness of the cartilagenous covering of the human femoral bone head, normal (20), different values of microstiffness have been defined in various zones, depending on their functional load and thickness of the cartilage. The data obtained can serve for construction of subtotal endoprostheses of the coxal joint.     

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.     

Changes of heavy metal concentrations in cross-sections of human femur head

The concentrations of 12 elements (Ni, Ma, Cr, Cd, Pb, Cu, Fe, Zn, Mg, K, Na, Ca) were determined in cross-sections of human femur heads. The highest concentrations of these elements was found in the cortical bone, and the lowest concentrations occurred in the trabecular bone, with exception of the E cross-section, in which the lowest values were found in articular cartilage. The average concentrations of Na, Ca, K, and Mg were highest in cortical bone and lowest in articular cartilage. Pb was found in higher concentrations in articular cartilage and lowest in trabecular bone, with exception of cross-sections A and E. The Fe contents in the cortical parts were highest in cross-sections A, B, and D. Cu was highest in cross-sections B, C, and D of articular cartilage. These results show that the contents of the selected metals in the femur head varied considerably. As expected, the largest concentrations were found in the outmost part of cross-section E and the lowest in its innermost one, possibly related to mechanical stress.     

A histopathological and morphometrical study of femur head cartilage in Wistar rats treated with prednisolone

An analysis was made of histopathological developments in femur head cartilage in a group of Wistar rats receiving a daily intra-muscular injection of 2.5 mg prednisolone. This group was divided into four experimental batches, each consisting of 6 rats. Batches were sacrificed at 15, 30, 60 and 90 days after the start of the experiment. Degeneration of the femur head cartilage was observed from the start of the experiment (15 days), and gave rise to chondrocyte necrosis by 90 days. Structural modifications are shown morphologically and morphometrically.     

Aseptic necrosis of the head of the femur in patients with major rheumatic diseases of inflammatory and dystrophic genesis

A total of 2392 patients treated at the Unit of Rheumatology, Tula Regional Hospital, in 2002 and 2003 were analyzed. Among them, there were 71 patients who were found to have aseptic necrosis of the head of the femur. A statistical analysis of clinical, laboratory, and X-ray data revealed a number of correlations. It was established that the risk factors of aseptic necrosis of the femoral heads were anemia concurrent with the high laboratory values in rheumatoid arthritis and elevated lipid levels and blood coagulative system activation in primary coxarthrosis.     

X-ray diagnosis of aseptic necrosis of the femur head in adults at the preclinical stage

The time course of an x-ray picture from the normal bone structure up to the appearance of positive x-ray signs of aseptic necrosis of the head of the femur (ANHF) was followed-up. The former, appearing long before the development of clinical signs of disease, were foci of the rarefaction of a round or oval shape in the upper, central parts of the head of the femur, and along its periphery in somewhat dense or normal structure of the head of the femur.     

Morphological characteristics of the acetabulum

The aim of this research was to accurately measure the surface of the semi lunar articular surface of the pelvis (facies lunata acetabuli) and the variability of the acetabular geometry, as well as to determine the correlation between measured parameters. 30 macerated anatomical specimens of pelvic bones were measured. The radius and depth were measured in the classical way, while cartilaginous surface area was measured using small fragments of measuring paper to avoid errors in measurement due to the curvature of the surface. Computerized calculations provided accurate surface values. In our research, facies lunata acetabuli measured 2294+/-329 mm2. Diameter of the opening of the acetabulum measured 25.8+/-1.9 mm. Acetabular depth was 30+/-3.2 mm. Correlations between the surface area of the facies lunata acetabuli and the radius of the acetabular opening curvature (r=0.71), surface area of the facies lunata acetabuli and the depth of the acetabulum (r=0.80) and the radius of the acetabular opening curvature and the depth of the acetabulum (r=0.80) were confirmed. For precise assessment of the facies lunata acetabuli surface area, the simplest and the cheapest method is the method of measurement using small fragments of measuring paper and software analysis. There is a significant correlation between the depth, opening of the acetabulum and surface area of the facies lunata.