Normal Epiphyseal Cartilage Research Articles

Multiparametric MRI of Epiphyseal Cartilage Necrosis (Osteochondrosis) with Histological Validation in a Goat Model

PurposeTo evaluate multiple MRI parameters in a surgical model of osteochondrosis (OC) in goats.MethodsFocal ischemic lesions of two different sizes were induced in the epiphyseal cartilage of the medial femoral condyles of goats at 4 days of age by surgical transection of cartilage canal blood vessels. Goats were euthanized and specimens harvested 3, 4, 5, 6, 9 and 10 weeks post-op. Ex vivo MRI scans were conducted at 9.4 Tesla for mapping the T1, T2, T1ρ, adiabatic T1ρ and TRAFF relaxation times of articular cartilage, unaffected epiphyseal cartilage, and epiphyseal cartilage within the area of the induced lesion. After MRI scans, safranin O staining was conducted to validate areas of ischemic necrosis induced in the medial femoral condyles of six goats, and to allow comparison of MRI findings with the semi-quantitative proteoglycan assessment in corresponding safranin O-stained histological sections.ResultsAll relaxation time constants differentiated normal epiphyseal cartilage from lesions of ischemic cartilage necrosis, and the histological staining results confirmed the proteoglycan (PG) loss in the areas of ischemia. In the scanned specimens, all of the measured relaxation time constants were higher in the articular than in the normal epiphyseal cartilage, consistently allowing differentiation between these two tissues.ConclusionsMultiparametric MRI provided a sensitive approach to discriminate between necrotic and viable epiphyseal cartilage and between articular and epiphyseal cartilage, which may be useful for diagnosing and monitoring OC lesions and, potentially, for assessing effectiveness of treatment interventions.

Normal Epiphyseal Cartilage Measurements in the Knee in Children

The purpose of this study was to validate previously reported distal femoral cartilage measurements in healthy children of different ages using an alternative sonographic imaging plane and patient position than previously reported and to provide preliminary proximal tibial epiphyseal cartilage measurements in healthy children. Distal femoral and proximal tibial epiphyseal cartilage thickness was measured using sonography in a cohort of healthy children based on a coronal image at the medial aspect of the femorotibial joint with the knee in 30° of flexion. The average of 3 measurements of femoral and tibial epiphyseal cartilage was obtained and correlated with age and sex. Femoral epiphyseal cartilage measurements were compared to recently reported measurements at the patellofemoral joint. Sixty children (31 boys and 29 girls; newborn to 21 years; mean, 9 years; median, 7 years 11 months) were imaged. Seventy-four percent of distal femoral cartilage epiphyseal measurements fell into the 95% confidence intervals predicted by previously published reports. At age ranges outside those previously reported, there was less concordance between measured cartilage thickness values and those predicted. Values of distal femoral epiphyseal cartilage thickness measured by sonography of the femorotibial joint are similar to those reported at the patellofemoral joint. We propose that femoral epiphyseal cartilage thickness be measured on the basis of a coronal image at the medial femorotibial joint. This technique requires less knee flexion, which may prove advantageous when evaluating cartilage in patients with joint inflammation and a limited range of motion. It also allows concurrent measurement of tibial epiphyseal cartilage and thus provides another parameter for assessing cartilage loss.

Effects of Dietary Calcium Levels on the Histomorphology of Proximal Tibia in Vitamin D-deficient Chicks.

This study was conducted to clarify the effects of dietary calcium levels on tibia histomorphology in young growing chicks fed a vitamin D-deficient diet. Male day-old chicks were fed vitamin D-deficient diets either normal (1.0%) or high (2.0%) in calcium for 4 weeks. Proximal tibiae were excised and longitudinal sections were examined by light microscopy. Morphological differences were quantified by a computerlized histomorphometry. The feeding of the normal calcium diet caused significant increase in the width of epiphyseal cartilage and histomorphometric indices of bone resorption. Osteoclastic resorbing surface and all osteoclast parameters, measured at metaphysis, greatly increased in the normal calcium diet chicks compared to the controls fed the vitamin D-replete diet. The area of osteoblasts remarkably decreased in the normal calcium diet chicks. Changes in these bone cell parameters are thus associated with marked decrease in trabecular bone volume, expressed as percentage of the mineralized bone matrix area. In contrast, tibiae of the high calcium diet chicks were not significantly different from bones of the control chicks with respect to histological features and most parameters. Thus, tibia histomorphology in the high calcium diet chicks showed normalization of bone as observed in the vitamin D-replete diet chicks. These results indicate that in the growing chick continued feeding of a diet with high calcium content can maintain nearly normal epiphyseal cartilage width and metaphyseal bone histomorphology and mineralization in the absence of vitamin D.

Immunohistochemical distribution of s-100 protein in tumors and tumor-like lesions of bone and cartilage

Various tumors and tumor-like lesions of bone and cartilage were examined for S-100 protein using the avidine-biotin-peroxidase complex (ABC) immunostaining method. The most intense reactivity for S-100 protein was found in well-differentiated chondrocytes of enchondromas, osteochondromas and chondrosarcomas, and in normal epiphyseal cartilage. S-100 protein was positive in both polygonal stromal cells and chondrocytes of chondroblastomas and in chondrocytes of mesenchymal chondrosarcoma. In osteosarcomas not only chondroblastic areas but also osteoblastic areas showed positive cells. Reticulum histiocytic cells of eosinophilic granulomas and chordoma cells were positive for S-100 protein. The study yielded three main conclusions: (1) S-100 protein could be the marker for tumors of cartilaginous origin and differentiation, notochord origin, and T-zone histiocyte origin; (2) chondroblastoma can be distinguished from other histologically confusing giant cell lesions by using ABC to detect S-100 protein; and (3) S-100 protein has some relationship with tumoral calcification not only in cartilaginous tumors but also in osteosarcoma.

Legg-Calvé-Perthes disease. Histochemical and ultrastructural observations of the epiphyseal cartilage and physis.

Biopsy specimens of the lateral aspect of the femoral head and neck were obtained from five children with Legg-Calvé-Perthes disease and were studied using histochemistry and electron microscopy. Beneath the normal articular cartilage there was a thick zone of hyaline (epiphyseal) cartilage containing sharply demarcated areas of hypercellular and fibrillated cartilage with prominent blood vessels. The fibrillated cartilage was strongly positive to alcian blue, weakly positive to periodic acid-Schiff, and positive to aniline blue. The interterritorial matrix in the hypercellular areas was weakly positive to both alcian blue and periodic acid-Schiff. Ultrastructural examination of these areas revealed many irregularly oriented large collagen fibrils and variable amounts of proteoglycan granules. These results suggest that in the fibrillar areas there are: (1) a high proteoglycan content, (2) a decrease in structural glycoproteins, and (3) a different size of collagen fibrils from that of normal epiphyseal cartilage. The hypercellular areas had a decrease in proteoglycans, glycoproteins, and collagen. The lateral physeal margin was often irregular, with a marked reduction of collagen and proteoglycan granules, and contained numerous large lipid inclusions. The abnormal areas in the epiphyseal cartilage of patients with Legg-Calvé-Perthes disease have different histochemical and structural properties from normal cartilage and from fibrocartilage. This suggests that the disease could be a localized expression of a generalized, transient disorder of epiphyseal cartilage that is responsible for delayed skeletal maturation. The cartilage lesions are similar to those seen in the vertebral plates in patients with juvenile kyphosis. Whether the epiphyseal cartilage abnormalities are primary or are secondary to ischemia remains uncertain; however, it appears that the collapse and necrosis of the femoral head could result from the breakdown and disorganization of the matrix of the epiphyseal cartilage, followed by abnormal ossification.

The Effects of Manganese, Biotin, and Choline on Hexosamine and Hydroxyproline Content as Related to Leg Weakness

Three experiments were conducted with day-old broiler chicks to determine the effects of dietary choline, biotin, and manganese on cartilage hexosamine and hydroxyproline content. The incidence of leg weakness was 75% or higher on all basal diets. The levels of supplementation found to minimize leg weakness were 1540 mg choline chloride/kg diet, .2 mg biotin/kg diet, and 100 mg manganese/kg diet. The levels required to maintain normal epiphyseal cartilage hexosamine content were 385 mg of choline chloride, .05 mg of biotin, and 25 mg of manganese/kg of diet. Substantially higher levels of nutrients were needed to reduce the incidence of leg weakness. Only with manganese supplementation was the incidence of leg weakness significantly reduced at the level of supplementation required for normal hexosamine content. Hydroxyproline content was not affected by varying the levels of supplemental choline, biotin, or manganese.

Cell Death in the Normal Epiphyseal Cartilage of the Rat

The ultrastructure of the upper tibial epiphyseal cartilage plate of weanling and plateaued Sprague-Dawley rats growing under normal conditions has been studied, in order to establish a base-line for the future investigation of the site and mechanism of action of certain hormones which are known to affect the growth and maturation of long bones.Observations have been made concerning the character and amount of the secretory products in the cells of the various zones, as well as the characteristics of the constituents of the intercellular matrix. Our findings have confirmed and amplified published observations on the ultrastructure of cartilaginous tissues in a variety of species in general.