Kinematic accuracy of three surface registration methods in a three-dimensional wrist bone study

The use of registration techniques to determine motion transformations noninvasively has become more widespread with the increased availability of the necessary software. In this study, three surface registration techniques were used to generate carpal bone kinematic results from a single cadaveric wrist specimen. Surface contours were extracted from specimen computed tomography volume images of the forearm, carpal, and metacarpal bones in four arbitrary positions. Kinematic results from each of three registration techniques were compared with results derived from multiple spherical markers fixed to the specimen. Kinematic accuracy was found to depend on the registration method and bone size and shape. In general, rotation errors of the capitate and scaphoid were less than 0.5 deg for all three techniques. Rotation errors for the other bones were generally less than 2 deg, although error for the trapezoid was greater than 2 deg in one technique. Translation errors of the bones were generally less than 1 mm, although errors of the trapezoid and trapezium were greater than 1 mm for two techniques. Tradeoffs existed in each registration method between image processing time and overall kinematic accuracy. Markerless bone registration (MBR) can provide accurate measurements of carpal kinematics and can be used to study the noninvasive, three-dimensional in vivo kinematics of the wrist and other skeletal joints.     

Carpal bone maturation assessment by image analysis from computed tomography scans

Bone maturation is the only reliable indicator of growth and its radiologic assessment with or without automated systems is a qualitative method. Image processing allows the study of bone maturation with quantitative data. Carpal bone maturation was studied in 20 children (13 boys and 7 girls, ages ranging from 4 to 15 years) without any clinical evidence of endocrine disease by image analysis from computed tomography (CT) scans. Each wrist CT scan was processed in order to extract the carpal bones and to measure quantitative data regarding volume, axes of inertia and density for each bone. The volumes and the length of the inertia axes were significantly correlated with age. Whatever the age, there were strong correlations between the volume or the length of the main inertia axis of one carpal bone and that of all others. The decrease in the carpal bone volume measured from the processing procedure compared with the theoretical volume of bone defined from the length of the three inertia axes indicated a change in bone shape during growth. Although the mean density was constant, there was an increase in the standard deviation of density with age. Skeletal maturity assessment with image analysis from CT scans seems to be a good complementary investigation to determine bone age in children.     

Coordinate systems for the carpal bones of the wrist

The eight small and complexly shaped carpal bones of the wrist articulate in six degrees of freedom with each other and to some extent with the radius and the metacarpals. With the increasing number and sophistication of studies of the carpus, a standardized definition for a coordinate system for each the carpal bones would aid in the reporting and comparison of findings. This paper presents a method for defining and constructing a coordinate system specific to each of the eight carpal bones based upon the inertial properties of the bone, derived from surface models constructed from three-dimensional (3-D) medical image volumes. Surface models from both wrists of 5 male and 5 female subjects were generated from CT image volumes in two neutral wrist positions (functional and clinical). An automated algorithm found the principal inertial axes and oriented them according to preset conditions in 85% of the bones, the remaining bones were corrected manually. Six of the eight carpal bones were significantly more extended in the functional neutral position than in the clinical neutral position. Gender had no significant effect on carpal bone posture in either wrist position. Correlations between the 3-D carpal posture and the commonly used 2-D clinical radiographic carpal angles are established. 3-D coordinate systems defined by the anatomy of the carpal bone, such as the ones presented here, are necessary to completely describe 3-D changes in the posture of the carpal bones.     

The estimation of age at death and ages of formation of transverse lines from measurements of human long bones

A radiographic method is presented which estimates the age at death from the diaphyseal length of a child's long bone or bones. Mean lengths are calculated from adult males and females separately in the skeletal population under study, and the child's age derived from the proportion of adult length attained at his or her death. The calculations come from double logistic curves originally derived from a sample of Colorado children (McCammon, 1970). In radiographs of immature or adult long bones, similar equations are based on the location of the center of ossification, from which distances to transverse lines yield estimated ages when these lines were formed. In a population, ages at death, ages of attainment of transverse lines, and ages when anomalous enamel is laid down in teeth are all contributions to paleopathology and paleodemography. These equations can predict when spaced transverse lines were annually formed. If such spaced lines can be seen in radiographs of early fossil hominids, their spacing can distinguish between short childhood, as in apes, and the longer immature developmental span found in modern children.     

Comparison of Tanner-Whitehouse and Greulich-Pyle methods in a large scale Danish Survey

In Denmark no systematic investigation of skeletal development had been made prior to this investigation which involved 1009 school children aged 7–18 years in a transverse examination. The skeletal age was estimated according to the American atlas of Greulich-Pyle. The English system of Tanner-Whitehouse was also applied. In this latter method the stage of development of 20 selected bones in the hand and wrist is rated on a scale of 8 (in one case 9) possible stages. Each bone is awarded points according to its stage of development. These points are totalled for the 20 bones and reference to a table gives the skeletal age. The problem with this system is that the later stages of carpal bone development cannot be reliably placed on the scale. Their point system is calculated in such a way that a difference of one stage in rating of a single carpal bone in older children would give rise to a difference of up to two years in the skeletal age estimation. For younger children the method is, however, quite reliable. The investigation has shown that Greulich-Pyle's atlas can be applied to Danish children of 7-18 years of age provided that a correction of six months is made. A variable error of about four months was found when using Greulich-Pyle compared to about two months with Tanner-Whitehouse.     

Skeletal maturation of children in Shiraz, Iran

Hand-wrist radiographs were made of 4,551 Shiraz school children and well babies of known age who were also weighed and measured. Medical examinations were not made and selection was biased in favor of the advantaged child because the urban standard of living is higher than the rural in Iran and because the poorest children may not attend elementary school and never attend high school. Nevertheless, height, weight and bone age fell rapidly below the tenth Iowa percentile by the age of two years and did not begin recovery until the age of six years. The distribution of the bone ages in each group was symetrical, not bi-modal. Bone age offered no advantage over height age as an index of development but analysis of the radiographs provided evidence that the retardation was pathologic rather than genetic. Ossification of individual epiphyses was recorded in 3,333 hands and a marked discrepancy between carpal and phalangeal bones, with the carpal bones most retarded, was documented. A high incidence of pseudoepiphyses was noted.     

A digital database of wrist bone anatomy and carpal kinematics

The skeletal wrist consists of eight small, intricately shaped carpal bones. The motion of these bones is complex, occurs in three dimensions, and remains incompletely defined. Our previous efforts have been focused on determining the in vivo three-dimensional (3-D) kinematics of the normal and abnormal carpus. In so doing we have developed an extensive database of carpal bone anatomy and kinematics from a large number of healthy subjects. The purpose of this paper is to describe that database and to make it available to other researchers. CT volume images of both wrists from 30 healthy volunteers (15 males and 15 females) were acquired in multiple wrist positions throughout the normal range of wrist motion. The outer cortical surfaces of the carpal bones, radius and ulna, and proximal metacarpals were segmented and the 3-D motion of each bone was calculated for each wrist position. The database was constructed to include high-resolution surface models, measures of bone volume and shape, and the 3-D kinematics of each segmented bone. The database does not include soft tissues of the wrist. While there are numerous digital anatomical databases, this one is unique in that it includes a large number of subjects and it contains in vivo kinematic data as well as the bony anatomy.     

Growth of wild and laboratory born chimpanzees

The skeletal remains of a wild juvenile chimpanzee,Pan troglodytes verus, of known chronological age are measured and found to be smaller than laboratory born and fed juveniles of the same age. Other wild born immature skeletal materials of all the three subspecies ofPan troglodytes, including both known and estimated chronological ages, are also smaller than laboratory born chimpanzees when comparisons are made on corresponding age groups. Differences between wild and laboratory born chimpanzees are larger in the limb bones than in the cranium. Limb bones of laboratory individuals grow earlier than those of wild ones regardless of subspecies. Small limb bone size of wild chimpanzees is discussed in terms of life processes.     

Appendicular skeletal morphology in minute salamanders,genus Thorius (amphibia: Plethodontidae): Growth regulation,adult size determination,and natural variation

Patterns of growth and variation of the appendicular skeleton were examined in Thorius, a speciose genus of minute terrestrial plethodontid salamanders from southern Mexico. Observations were based primarily on ontogenetic series of each of five species that collectively span the range of adult body size in the genus; samples of adults of each of seven additional species provided supplemental estimates of the full range of variation of limb skeletal morphology. Limbs are generally reduced, i.e., pedomorphic, in both overall size and development, and they are characterized by a pattern of extreme variation in the composition of the limb skeleton, especially mesopodial elements, both within and between species. Fifteen different combinations of fused carpal or tarsal elements are variably present in the genus, producing at least 18 different overall carpal or tarsal arrangements, many of which occur in no other plethodontid genus. As many as four carpal or tarsal arrangements were observed in single population samples of each of several; five tarsal arrangements were observed in one population of T. minutissimus. Left-right asymmetry of mesopodial arrangement in a given specimen is also common. In contrast, several unique, nonpedomorphic features of the limb skeleton, including ossification of the typically cartilaginous adult mesopodial elements and ontogenetic increase in the degree of ossification of long bones, are characteristic of all species and distinguish Thorius from most related genera. They form part of a mechanism of determinate skeletal growth that restricts skeletal growth after sexual maturity. Interspecific differences in the timing of the processes of appendicular skeletal maturation relative to body size are well correlated with interspecific differences in mean adult size and size at sexual maturity, suggesting that shifts in the timing of skeletal maturation provide a mechanism of achieving adult size differentiation among species. Processes of skeletal maturation that confer determinate skeletal growth in Thorius are analogous to those typical of most amniotes – both groups exhibit ontogenetic reduction and eventual disappearance of the complex of stratified layers of proliferating and maturing cartilage in long bone epiphyses – but, unlike most amniotes, Thorius lacks secondary ossification centers. Thus, the presence of secondary ossification centers cannot be used as a criterion for establishing determinate skeletal growth in all vertebrates.     

Problems in combining skeletal age for an individual

Maturity imbalance between bones from different areas of the body, or between different bones in the same area or even between different centers within the same bones, are not an infrequent experience in doing radiographic assessment of skeletal maturation. Data from previous works have demonstrated tremendous variation concerning the pattern, degree, and causes of the imbalance. In view of the incomplete and contradictory knowledge concerning the mechanism producing such imbalance, it was only recommended to obtain the unweighted arithmetic mean of all the separately assessed bones as the overall skeletal age for an individual. It was hoped, however, that enthusiastic collection of new data on multiple bone assessments would soon take place which would facilitate a further recognition of the significance in skeletal maturity imbalance.     

用显微镜确定骨龄的初步研究

作者对在广西地区收集的年龄从5岁至86岁的35副完整骨骼的右股骨中点横断磨片的骨单位数、骨间板数、非哈弗氏管数及外环骨板平均相对厚度进行了观测和计算。这些指标与年龄之间均存在非常显著的相关,并建立了相应的回归方程。这些回归方程的估计年龄与实际年龄的误差在±5岁以内的,达80％左右;在±10岁以内的,达90％左右。与用Kerley法所作的对比检验表明,本文方法较适用于国人材料。     

Intraskeletal variability in bone mass

For methodological or other reasons, a variety of skeletal elements are analyzed and subsequently used as a basis for describing general bone loss and mass. However, bone loss and mass may not be uniform within and among skeletal elements of the same individual because of biomechanical factors. We test the hypothesis that a homogeneity in bone mass exists among skeletal elements of the same individual. Measures indicative of bone mass were calculated from the midshafts of six skeletal elements from the same individuals (N = 41). The extent of intraskeletal variability in bone mass (relative cortical area) was then examined for the entire sample, according to age, sex, and pathological status. The results of the analysis showed that all measures reflect a heterogeneity in bone mass (P 相似文献   

Weight of the skeleton during postnatal development

The weight of all bones and the length of humeri, radii, femora and tibiae have been determined in a series of 150 dry, fat-free skeletons from American Whites and Negroes of both sexes, ranging in age from 23 days to 22 years. Six skeletons were eliminated from the series because of evidence of previous illness. A comparison of the lengths of femur plus tibia of this series with the mean statures of a large series of living children at given ages indicates similarity in the growth patterns. Statistical analyses of the data show that the skeletal weight cannot be estimated reliably from age by cither an exponential growth equation or by a logistic function. The weight of the skeleton, however, is related to the lengths of the measured limb bones by allometric equations, and such equations involving each of the four bones are presented for estimation of skeletal weight in the living. Although the standard errors of estimate of the equations based on lengths of each of these four bones differ very little, the radius is recommended over the other three because it is more readily accessible in the living for a roentgenogram and its shadow on the film shows least distortion.     

The measurement of skeletal maturity

A new approach to the measurement of skeletal maturity has been described. This was applied to the distal end of the femur in boys aged one month to four years. It is planned to extend this study to girls and to other ages and sites and to other bones in the knee area. The study began with the testing of reported indicators of skeletal maturity in respect of replicability, validity, discrimination and universality. As a result, seven qualitative graded indicators and three quantitative ratios were selected for further investigation. Maturity scores based on each qualitative indicator can be estimated using parameters from a simple probit analysis with chronological age as the independent variable. The statistical factors that influence the usefulness of these indicators have been discussed. The quantitative indicators investigated appear very useful as measures of maturity although some are redundant. The planned extension of the present study should allow the formulation of an appropriate model for the measurement of skeletal maturity by combining qualitative and quantitative data.     

Scoring system for estimating age in the foot skeleton

This study assesses chronological age of immature individuals from the degree of ossification evident in the foot skeleton. We considered all tarsal and ray bones in various combinations to determine the most sensitive indicators of chronological age. Skeletal maturity was rated according to a subjective but simple scoring system applied to radiographs of normal feet of children of known chronological age. Scales for assessing the primary center of ossification, secondary center of ossification, and state of fusion are defined. In general, as expected, females show earlier onset of skeletal maturity than males; in particular, females in our sample are skeletally mature in most elements beginning 48 months prior to the earliest incidence of skeletal maturity in males for the same bones. Females in our sample show a marked tendency toward skeletal maturity of all elements by 150 months of age, while males do not show the same tendency until approximately 200 months of age. In general within each sex, consecutive states of fusion show broad overlap in range of chronological age within each bone. Combining scores from several different bones enables a reasonable estimate of potential age in a test application of the model.     

Age and sex bias in the reconstruction of past population structures

Palaeodemographical studies are founded on the assumption that the sex and age distribution of the skeletal sample reflects the constitution of the original population. It is becoming increasingly clear, however, that the type and amount of information that may be derived from osteoarchaeological collections are related to the state of preservation of remains. This work proposes a new method to evaluate bone preservation, to identify age and sex biases in the preservation of human skeletal remains, and to assess whether differences in preservation patterns are more dependent on factors intrinsic or extrinsic to anatomical features of human bones. Three osteological collections and over 600 skeletons were observed. The state of preservation of human bones was assessed using three preservation indexes: the anatomical preservation index (API), the bone representation index (BRI), and the qualitative bone index (QBI). The results suggest that subadult skeletons are generally more poorly preserved and with bones less well-represented than adult skeletons. Among subadults, female and male skeletons have different patterns of preservation according to their age. This pattern of preservation depends on intrinsic anatomical properties of bones themselves, while external factors can only increase these differences in the state of preservation and representation of osseous remains. It is concluded from this that failure to recognize these differences may lead to misleading interpretations of paleodemography of past human populations.     

Senegalese sole bone tissue originated from chondral ossification is more sensitive than dermal bone to high vitamin A content in enriched Artemia

Several studies have evaluated the effects of dietary vitamin A (VA) on the incidence of skeletal deformities during early ontogeny of fish, but little is known about its effects on bones depending on their process of ossification (dermal or chondral). We examined the incidence of skeletal deformities along development (30 and 48 dph) by double staining technique, in dermal (haemal and caudal vertebral bodies) and chondral (neural and haemal spines, epural, parahypural and hypurals) bones in Senegal sole post metamorphosed larvae fed with different dietary VA levels (37 000, 44 666, 82 666 and 203 000 UI total VA kg^?1 DW) during Artemia feeding phase (6–37 dph, at 18°C). Results obtained in this study showed that dietary VA disrupted the skeletogenesis in Senegalese sole post metamorphosed larvae by increasing the incidence of skeletal deformities in the axial skeleton and caudal fin complex, which were dependent on both bone morphogenesis and ossification processes. Fish fed with the highest dietary VA content showed the highest incidence of skeletal deformities and its value increased along ontogeny. However, when we compared the incidence of deformities in skeletal structures considering their ossification process, most skeletal structures derived from chondral ossification showed a significant higher increase in deformity incidences in fish fed an excess of VA (44 666, 82 666 and 203 000 UI kg^?1 DW), however within chondral bones, hypurals deformity incidence only increased in sole larvae fed Artemia highest VA content. In contrast, this dietary dose‐response effect was only noted in dermal bones from fish fed the highest dose of VA (203 000 UI kg^?1 DW). In addition, the incidence of deformities in chondral bones increased even when the dietary imbalance of VA was corrected, whereas dermal bones were not affected at later ages. These results indicated that depending on the ossification process from which different skeletal structures are derived, bones might be differentially affected by high dietary VA content. Those directly originated from the connective tissue with a preliminary cartilage stage were more sensitive to dietary VA excess than those formed by intramembranous ossification.     

Associations between the rates of maturation of the bones of the hand-wrist

Skeletal maturation rates for the age interval 3 to 13 years were analyzed using bone-specific assessments (Greulich-Pyle) of serial radiographs of 40 children. The mean rates of skeletal maturation resembled those of the population from which the atlas standards had been derived. There was a linear trend of skeletal age against chronological age for most bones in each sex. Regression lines were fitted to these data and the b values of the regression lines were calculated. Communality indices were calculated from an intercorrelation matrix of these b values. There was a statistically significant rank order correlation between the sexes in the communality indices. They tended to be higher in the girls than in the boys and were relatively low for the radius, ulna and carpals. Communality indices within groups of bones were high in all rows, especially the metacarpals, but in each sex they were comparatively low in the first ray (metacarpal plus the phalanges of the corresponding digit) and in the fifth ray of the boys. Neighborhood effects on the levels of association of maturation rates were present, particularly in the carpus, but marginal effects were not noted.     

Difference in size of bone islands formed by isolated bone cells transplanted intramuscularly under various conditions.

Bone cells isolated from the whole calvaria (2 x 10(6)) from either central or peripheral parts of parietal bones (1 x 10(6)) and from scapulas (2 x 10(6)) were allowed to adhere to devitalized calvarial bones in the number indicated in brackets and transplanted intramuscularly (supported transplants). Whole calvaria bone cells (2.4 or 8 x 10(6) cells per transplant) were also injected intramuscularly as free transplants. Calvarial cells produced solid bone islands with small intraosseous cavities, while bone formed by scapular cells contained large medullary spaces. The size of bone islands formed in transplants and the shortest distance between the neighbor islands were measured. The results of these measurements were similar in all groups of free transplants. The size of bone islands formed in supported transplants of cells from the whole calvaria or from central and peripheral parts of parietal bones was also roughly similar, but the shortest distance between islands was larger than in the free transplants. Furthermore, in these groups of transplants bone islands considerably larger than the largest islands in free transplants were present. Scapular bone cells formed islands much larger than those produced by calvarial cells. Bone islands formed by calvarial cells in free transplants were separated by bands of fibrous tissue which was absent in supported transplants. It appears that this tissue could limit growth and/or fusion of neighbor bone islands and in this manner influence their size. The population of transplanted scapular cells contained numerous stromal elements which could form an exclusion area inaccessible to local cells from the site of transplantation and thus favour formation of large bone islands within this area.