Intraosseous infusion of resuscitative fluids and drugs: long-term effect on linear bone growth in pigs

We studied the effects of intraosseous (IO) infusion of a standard fluid bolus and resuscitative drugs on long-term bone growth and epiphyseal closure in the "pediatric" swine model. Eighteen weanling pigs were randomly assigned to six groups as follows: three animals received two normal saline boluses, 20 mL/kg IO over 20 minutes; three received sodium bicarbonate, 1 mEq/kg IO; three received a 10% sodium bicarbonate infusion IO at maintenance rate over 1 hour; three received epinephrine 1:10,000, 0.1 mL/kg IO; three received an epinephrine infusion IO at 1 microgram/kg/min for 1 hour; and three received a dopamine infusion IO at 10 micrograms/kg/min for 1 hour. All infusions were given in the left hindleg; the right hindleg was used as a control. Lateral radiographs of the hind extremities were obtained at the beginning of the study and at 1 and 3 months after infusion. Linear radiographic measurements of the infused and control tibias were compared. At 6 months after infusion, the tibias were harvested, measured directly, and radiographed to determine the degree of epiphyseal closure. Analysis of variance for the first 3 months' data yielded a nonsignificant time-by-treatment interaction (P = .84) and a nonsignificant main effect for time (P = .22). Separate analysis of the direct measurements taken at 6 months revealed no difference in growth between experimental and control tibias. In addition, no radiographic difference in epiphyseal closure was noted between the two groups at the conclusion of the study, nor were any structural defects discovered. Intraosseous infusion of fluids and resuscitative drugs does not adversely affect subsequent bone growth and development in the swine model.

Cartilaginous epiphysis and growth plate: normal and abnormal MR imaging findings

The cartilaginous structures at the ends of growing bones constitute the "growth mechanism." These structures are not visible on radiographs, but they can be seen with MR imaging. Improved definition of cartilaginous abnormalities by MR imaging may permit earlier detection and treatment of these disorders and thus prevent bone deformity. This pictorial essay contains examples of normal and abnormal growth cartilage as seen with MR imaging. The indications for MR imaging in the evaluation of certain growth disorders are discussed, and the usefulness of MR imaging in certain clinical situations in which the role of this technique is still evolving is illustrated.

Morphology of epiphyseal apparatus of a ranid frog (Rana Esculenta)

Morphological, histochemical and ultrastructural investigations on epiphyseal apparatus of Rana Esculenta were made. The most important findings were the following: 1) metaphyseal cartilage is localized inside proximal diaphyseal compact bone as a plug; 2) metaphyseal cartilage do not reduce in thickness during ageing; 3) metaphyseal cartilage do not show vascular invasion and do not mineralize in degenerative zone; 4) trabecular bone was not at all evident in this animal; 5) external periosteum is well vascularized and proliferates in correspondence to marginal epiphyseal end of the diaphyseal. From these results the hypothesis that the ranid frog bone growth is not due to metaphyseal metabolism (as in avian and mammals) but to bone periosteal marginal mineralization is reached.

Growth of the perichondrium and the chondroepiphysis: experimental approach in the rat proximal tibial epiphysis

In the present paper we study the participation of the perichondrium in chondroepiphysis development analyzing its in vitro growth pattern without the perichondrium. We also advance the descriptive morphological results. We have observed that the chondroepiphysis without perichondrium grew with an almost normal pattern. Most of the cells that participated in chondroepiphysis growth came from the lateral region of the growth plate.

Epiphyseal marrow in infancy: MR imaging

Hypointense epiphyseal marrow on T1-weighted magnetic resonance images often suggests disease. To determine whether hypointense marrow sometimes represents normal red marrow in a recently ossified epiphyseal center, the authors studied 38 infants without known marrow disease. Patients with hypointense epiphyseal marrow on T1-weighted images were younger (3.9 months +/- 3.2) than those with hyperintense marrow (9.6 months +/- 3.9) (P less than .001). T1-weighted imaging and histologic correlation were also performed in animals. The signal was hypointense and the marrow was red in the epiphyseal centers of all newborn animals, while all 6-week-old animals had hyperintense signal and yellow marrow. The authors conclude that hypointense marrow on T1-weighted images represents normal red marrow in a recently formed ossification center in newborn rabbits and lambs, and the same is probably true in humans. Epiphyseal marrow becomes hyperintense within a few months of development of the secondary center of ossification.

In vivo quantitative characterization of trabecular bone by NMR interferometry and localized proton spectroscopy

In trabecular bone the NMR linewidth is found to be governed by the magnetic field inhomogeneity arising from the difference in magnetic permeability between bone and marrow. T2* was measured in vivo in the distal femur by interferometry and localized spectroscopy. Both methods showed T2* to be inversely related to trabecular plate density.

Postnatal epiphyseal development: the distal tibia and fibula

At birth, the distal tibial physis is a transverse structure. However, as the tibia enlarges diametrically and the epiphyseal ossification center matures, the physis becomes increasingly undulated, with peripheral lappet formation. The anteromedial area is the first to develop undulation (Poland's hump). This should not be misinterpreted as an injury or premature epiphyseodesis subsequent to trauma. The tibial secondary ossification center forms within the central epiphysis. The medial margin is irregular and may have peripheral foci of ossification. Between the ages of 7 and 8 years, this secondary center extends into the medial malleolus, reaching the distal tip during adolescence. The malleolar tip may develop accessory ossification. Physiologic epiphyseodesis begins over the medial malleolus and then extends laterally, a pattern of closure that affects fracture patterns (e.g., the fracture of Tillaux). The distal fibular physis also begins as a transverse structure that becomes undulated and has extensive peripheral lappet formation. This physis usually becomes level with the articular surface of the distal tibia after the first year. Enchondromalike extensions of the physis into the metaphysis are common. Accessory ossification may develop at the distal end.

Transphyseal linear ossific striations of the distal radius and ulna

Radiologic and histologic analysis of transphyseal linear ossific striations of the distal ulna and radius showed that these striations consist of trabecular bone extending from the metaphysis across all zones of the physis into a small focus of fibrous and necrotic tissue within the epiphyseal cartilage. The focus appears to be a discrete area of epiphyseal ischemia with subsequent necrosis within and around the vasculature of a cartilage canal and probably represents a microscopic response to antecedent trauma that was insufficient to cause macrofailure (fracture) of the physis. The striations did not continue into the epiphyseal ossification center. The consequence is partial osseous bridging across the physis. This bridging is unlikely to cause significant growth damage, since in most cases it does not appear to extend farther into the secondary ossification center.

Three-axial strain controlled testing applied to bone specimens from the proximal tibial epiphysis

Reproducibility of the determination of Young's modulus and energy absorption along the three axes of trabecular bone cubes was analysed by non-destructive compression to 0.5% strain using different testing protocols. These protocols included testing with and without pre-conditioning to a viscoelastic steady state, and different orders of test directions. Reproducibility of conditioned tests was generally better than that of non-conditioned tests. No major effect of changing the order of the test direction was found. Three-axial conditioned testing of cubes from the proximal tibial epiphysis of five humans revealed a global transverse isotrophy while most cubes showed orthotropy. The ratio between stiffness along the long axis of the tibia and the stiffness in the transverse plane was 3.7 +/- 0.4 (mean +/- 2 SE). The corresponding ratios for elastic energy storage and viscoelastic energy dissipation were 2.5 +/- 0.2. There was no difference between the relative energy loss during a testing cycle (loss tangent) in the three axes.

Estimating gestational age in the term pregnancy with a model based on multiple indices of fetal maturity

A prospective ultrasonographic study was conducted in 100 normal pregnant women with gestational ages that ranged from 36 to 42 weeks in which multiple biometric measurements were obtained. Dimensions of the distal femoral, proximal tibial, and proximal humeral epiphyseal ossification centers, as well as the placental and colonic grades, were also evaluated. A high statistical correlation was found between gestational age and each of the five variables (p less than 0.001). With a stepwise linear logistic regression analysis, we determined that gestational ages (36 to 39 weeks and 40 to 42 weeks) could be ascertained with a high probability with the use of a combination of the proximal humeral epiphysis and colonic grades. Probability estimates were not significantly affected by the addition of the distal femoral, proximal tibial epiphyses, placental grade, or amniotic fluid volume. From these data, probability prediction tables were generated. The results of this study provide an alternate method by which gestational age may be estimated in late pregnancy.

Bone age at birth; method and effect of hypothyroidism

Bone maturity at birth (or during the neonatal period) can be estimated from the ossified distal femoral epiphyses (FE). In congenital hypothyroidism (CHT) bone maturation is retarded and neonatal bone age reflects the severity of prenatal thyroid failure. In our reference group of 111 healthy infants, the size of these epiphyses depended not only on the age but also on body size. Thus, if bone age is estimated from the size of an epiphysis, the size of the infant is a potential confounder. This problem was avoided by estimating the maturation lag from the difference between the observed and predicted heights of FE (FEHs). Models for predicting FEH were constructed from data from the reference group by multiple linear regression and confirmed in a separate group of 37 healthy infants. In 52 hypothyroid newborns both FEH and FEH lag correlated with serum thyroxine concentration, indicating that FEH can be used as a measure of bone maturation in a population that is fairly homogeneous for (postmenstrual) age and size. Otherwise FEH lag is a better indicator.

The vascular supply of the chondro-epiphyses of the elbow joint in young swine

The vasculature of the elbow joint was examined in 39 pigs between one day and 15 weeks of age. Each pig was anaesthetised, exsanguinated and the thoracic limbs were perfused with India ink or a silicone rubber injection compound. The humerus, ulna and radius were dissected free, examined, fixed in formalin or ethyl alcohol, cleared by the modified Spalteholz technique and examined mesoscopically. Features of interest were photographed and then a limb from two pigs in each age group was cut into slabs and examined mesoscopically. The vascular supply of the distal part of the humerus was complex. It was supplied by vessels on both the cranial and caudal aspects and locally each aspect had a dual blood supply. Vessels anastomosed and on the cranial aspect formed a vascular ring. The proximal part of the ulna was supplied by vessels that were on its medial and lateral surfaces. The vessel on the lateral surface continued distally and supplied the lateral aspect of the proximal part of the radius. The proximal part of the radius was also supplied by arteries that were on the cranial and medial surfaces. Blood vessels provided branches to numerous cartilage canals of the articular-epiphyseal cartilage complexes, epiphyseal centres of ossification, and growth plates. The patterns of blood vessels in cartilage canals which were in sagittal or transverse planes were best exemplified by those in the distal part of the humerus. Perforating cartilage canals emerged from the epiphyseal centres of ossification. The pattern of cartilage canals was consistent in a general configuration, but individual variation did occur. Although cartilage canals were abundant in the youngest pigs, with increasing age the distribution of cartilage canals changed and the numbers of cartilage canals decreased.

The effect of a penetrating biodegradable implant on the growth plate. An experimental study on growing rabbits with special reference to polydioxanone

This study examined the fate of a biodegradable polydioxanone (PDS) implant in growing bone in rabbits. In 20 immature rabbits, a PDS rod 2.0 mm in diameter and 25 mm in length was driven into a drill hole of equal bore in the intercondylar portion of the right femur across the central portion of the growth plate. In another 25 immature rabbits, a PDS rod 3.2 mm in diameter and 25 mm in length was driven into a corresponding drill hole using the same technique. The follow-up intervals were three, six, 12, 24, and 36 weeks. The distal femoral growth plates of both femora were analyzed by roentgenographic, microroentgenographic, oxytetracycline-fluorescence, histologic, and histomorphometric studies. Histomorphometric studies showed clear changes at the site of injury and appeared to be an excellent means of providing an exact numerical description of the different cellular areas of the growth plate in experimental studies. A transphyseal PDS implant 2.0 mm in diameter did not cause any permanent growth disturbance of the femur in a growing rabbit. An implant 3.2 mm in diameter caused a growth disturbance similar to a drill hole of equal bore.

[Fractures in children]

Children's fractures can be divided into shaft fractures, epiphysiolysis and epiphyseal fractures. Shaft fractures always heal with conservative methods. Slight axis deviations and shortening will correct spontaneously, while fracture disease and pseudarthrosis are extremely rare. Nevertheless, acute complications such as compartment syndromes deserve special attention. Epiphyseal fractures call for anatomical reduction and foolproof fixation to prevent growth disturbance through partial or complete closure of the growth plate. Such growth disturbance is not to be expected in case of epiphysiolysis.

Morphometric analysis of cartilage canals in the developing mouse epiphysis

Cartilage canal development in the distal femoral epiphysis of 5- to 7-day-old mice can be divided into three stages as previously described [Cole and Wezeman, Am. J. Anat. 174: 119-129, 1985]. Using this model, a morphometric analysis of canal volume density at the three stages of development was performed and provided evidence that canal formation significantly exceeds epiphyseal growth. These data are consistent with initial canal formation by invasion rather than by inclusion.

Epiphyseal ossification centers in the assessment of fetal maturity: sonographic correlation with the amniocentesis lung profile

The epiphyseal ossification centers of the distal femur (DFE) and proximal tibia (PTE) appear and enlarge during the third trimester of pregnancy. Late in the third trimester, the epiphysis of the proximal humerus (PHE) begins to ossify in some fetuses. Using the amniocentesis lung profile to determine the value of sonographic epiphyseal visualization as a predictor of pulmonary maturity, we studied 50 fetuses prospectively and compared the sonographic epiphyseal findings with results from the amniocentesis lung profiles. Nine fetuses with a visible PHE had a mature amniocentesis lung profile (accuracy of positive prediction = 100%), and then fetuses with an immature amniocentesis lung profile had no visible PHE (conegativity = 100%). Fetuses in which the combined DFE and PTE diameters were greater than 11 mm or in which the DFE and the PTE diameters were similar in size (DFE less than or equal to 1 mm larger than PTE) also yielded positive results. Copositivity and accuracy of prediction of an immature amniocentesis lung profile, on the other hand, were low (22%-25%) for the same epiphyseal parameters. These data suggest that antenatal visualization and measurement of the epiphyseal ossification centers of the fetal knee and shoulder may help to identify fetuses that would have a mature amniocentesis lung profile.

The role of the epiphyseal and metaphyseal circulations on longitudinal growth in the dog: an experimental study

An experimental model using the immature canine proximal fibular epiphysis was developed to isolate and investigate the effects of the epiphyseal and metaphyseal circulations on longitudinal growth. Experimental constructs studied the epiphyseal circulation, the epiphyseal and metaphyseal circulations, a devascularized growth plate, and a control group. Twenty-four limbs were studied by serial x-ray films and microangiographic and histologic analyses at time of death, 24 weeks after surgery. The data from this preliminary study show that both metaphyseal and epiphyseal circulations are necessary for predictable longitudinal growth.

Vascular pattern of the developing proximal femur in the domestic fowl

The vascular pattern of the proximal femur and its importance in the aetiology of coxofemoral conditions has been established in many species, including man. In the avian femur, vascular lesions have been associated with pathological conditions. Ninety-six laying strain chicks were reared from day-old until 20 weeks. Birds were killed throughout the growth period and specimens were prepared for study. The origin and nature of epiphyseal vascular canals was established. Three principal stages of development occurred, namely growth plate formation, the growth period and the cessation of growth. Transphyseal vessels are described in the day-old chick to which a nutritive function is ascribed. Anastomosis did not occur between epiphyseal vascular canals. The epiphyseal vascular canals are grouped according to their source.

Effects of hot environments and carbonated drinking water on bone characteristics of eight-week-old broiler chicks

Epiphyses of the femura from 8-week-old broiler chicks were examined for morphology using scanning electron microscopy and for elemental composition using energy dispersive x-ray microanalysis. Birds between the ages of 4 and 8 weeks were subjected to either 25 or 35 C environments and given tap or carbonated drinking water. The morphological appearance of the epiphyses was affected by the kind of drinking water but not the thermal environment. Elemental constituents, however, were affected by both environmental temperature and drinking water.

Tibial epiphyseal development: a cross-sectional histologic and histomorphometric study in the New Zealand white rabbit

Sequential histomorphometric studies on the developing rabbit tibia from birth to skeletal maturity demonstrate that growth plate height lessens as longitudinal growth diminishes. Differing rates of development proximally and distally are documented. Distally, growth plate height, width, and area and total epiphyseal area peak or reach near maximum values by 3 weeks, whereas proximally, they do so by 8 weeks (except for height, which also peaks at 3 weeks). The distal growth plate is being obliterated by 16 weeks, at which time the proximal growth plate remains well structured and open. The distal tibia and fibula develop as one tissue mass. The articular cartilage and epiphyseal cartilage are continuous from birth, whereas a single ossification center and a single growth plate are present by 8 weeks. The data point to the presence of intrinsic growth plate, as well as systemic, control mechanisms affecting skeletal growth. Knowledge of temporal and quantitative features of epiphyseal and growth plate development will greatly aid in the elucidation of the underlying controls.

Epiphyseal union of the anterior iliac crest and medial clavicle in a modern multiracial sample of American males and females

Epiphyseal union of the anterior iliac crest and the medial clavicle is examined in 605 males and 254 females in a sample of modern Americans aged 11-40 years. The sample includes American whites, American blacks, Latin-Americans, and Orientals. This is the first skeletal investigation using a large sample of individuals of known age since the McKern and Stewart study of 1957. Epiphyseal union is analyzed in terms of four stages: 1) nonunion with no epiphyses, 2) nonunion with separate epiphyses, 3) partial union, and 4) complete union. The results provide broader age ranges for the stages of union than previous studies. Age ranges for males and females are similar or vary by only 1-2 years. Racially, no major distinguishing patterns are found except for greater variability in age distributions appearing to exist among American black females. The study furnishes valuable data on epiphyseal timing in the teenage years.

Discriminant function sexing of the tibia

The objective of the study was to test whether the shaft dimensions of the tibia were as sexually dimorphic as those of the femur and to develop a new sex determination technique from the tibia. Stepwise discriminant function subroutine based on a sample of 159 tibiae of blacks and whites of both sexes of the Terry Collection was employed for the study. Osteometric measurements included were the length, proximal and distal breadths, the circumference of the nutrient foramen and of the smallest shaft regions, and anteroposterior and transverse diameters at the nutrient foramen levels. The results indicated that in all dimensions proximal epiphyseal breadth and the minimum circumference were the variables selected by the stepwise function in blacks and that all but the transverse diameter participated in the function in whites. Average accuracy of sex determination was 87.3% for whites and 90.0% for blacks. For both races proximal epiphysis was a better indicator of sex differences than the remaining dimensions. While the study provided statistically reliable results sexual dimorphism was observed to be race dependent. This was especially true for blacks who provided higher prediction accuracy and more dimorphism than whites. Thus it was suggested that determination of sex required a consideration of not only growth related sex differences, and physical activity, but also the genetic (racial) nature of a population.

Aging and dietary modulation of rat skeleton and parathyroid hormone

Studies were carried out on SPF F344 male rats to evaluate the effects of aging and life-prolonging food restriction, without malnutrition, on rat skeleton and circulating PTH. Six-week-old F344 rats were divided into five groups. Group 1 rats were fed ad libitum a diet that contained 21% protein. Group 2 rats were fed 60% of the mean food intake of group 1 rats from 6 weeks of age for the rest of their lives. Group 3 rats were fed 60% of the ad libitum food intake until 6 months of age and then switched to ad libitum feeding. Group 4 rats were fed ad libitum until 6 months of age, and then switched to 60% of the ad libitum food intake. Group 5 rats were fed ad libitum a diet that contained only 12.6% protein so that these animals ingested the same amount of protein per day as the group 2 rats. In group 1 animals, bone length, weight, density, and calcium content increased rapidly with age and plateaued at about 12 months of age. There was no evidence of bone loss in these animals until about 24 months of age, but by 27 months, the animals had lost appreciable amounts of bone. The circulating immunoreactive PTH levels of the animals increased with advancing age, with a marked rise at 27 months. The age-related changes in bone and serum PTH levels of rats in groups 3 and 5 were similar to those of group 1 animals, except that a terminal increase in serum PTH did not occur in group 5 rats. In the groups 2 and 4 animals which were food restricted for the longest period, bone growth and maturation were slowed down, but the animals did not experience senile bone loss or marked terminal increase in circulating PTH. The salutary effects of food restriction were, therefore, not due specifically to the restriction of protein intake or to restricting food intake only during the period of rapid growth.

Pedicle graft epiphysis transplantation

Transfer of a graft taken from the iliac crest apophysis of 48 immature dogs was studied as a means of repairing an epiphysiodesis constituting more than 50% of the growth plate area. Four groups of dogs were studied. In Group I the graft was pedicled on the superficial circumflex iliac vessels and reimplanted in situ. In Group II the pedicled graft was transferred to the groin area as an island graft. These two control groups demonstrate the conservation of growth activity when the graft is pedicled on its epiphyseal vessels. In Group III the graft was transferred to the distal epiphyseal area of the femur after resection of the portion of the growth plate (approximately 2/3) located inside the perichondrial ring, with conservation of 80% of the outer portion of the cylinder. Microsurgical revascularization was achieved by using the saphenous vessels. In Group IV (the control group for Group III) the latter technique was used without revascularization. Roentgenography was performed for nine months after operation. The specimens were studied by tetracycline labeling and histologic and histochemical examinations. Results indicate that a well vascularized graft functions as a dynamic catalyst for regeneration of the resected portion of the growth plate and prevents the formation of bony bridges between the epiphysis and metaphysis by possible activation of the peripheral groove of Ranvier.