Inter-arm bone mass and size asymmetries in children tennis players are maturity status specific: a 9-month study on the effects of training time across pubertal change and somatic growth.

PURPOSE: Bone growth with exercise is best assessed by tennis-induced inter-arm asymmetries. Yet, the effects of training and maturation across puberty were unclear. This study explored arm bone growth across 9 months of training in 46 tennis players 7-14 years (25 boys, 21 girls). METHODS: Bone mineral content (BMC) and bone area (BA) were measured from DXA scans. Pubertal status was assessed by Tanner stage (TS) and somatic growth by maturity offset (MO). Children were grouped as pre- (TS I-I), early (TS I-II), and mid/late pubertal (TS II-III). RESULTS: Training time (TT) change in the three groups was 160-170, 190-230, and 200-220 h, respectively. Bone asymmetries were large in all groups (d > 0.8, P < 0.001): 5-18 g (9-21%) and 9-17 g (17-23%) in girls and boys, respectively, for BMC, and 5-15 cm2 (6-13%) and 9-15 cm2 (12-15%) in girls and boys (10-13%), respectively, for BA. BMC and BA change asymmetry peaked at pre-puberty in girls (56%, 46%) and at early puberty in boys (57%, 43%). Asymmetry gains varied with baseline asymmetry (41%) and change in TT (38%) and TS (17%) in BMC, and with baseline asymmetry (58%) and change in MO (17%) and TS (12%) in BA. CONCLUSION: All bone asymmetries were substantial. Tennis-induced bone gains were higher at pre- to early puberty in girls and at early to mid/late puberty in boys. Training enhanced mostly bone mass and maturity status enhanced mostly bone size; sex was not bone-change modeling impactful. Implications are discussed considering certain limitations.

Standardizing ordinal subadult age indicators: Testing for observer agreement and consistency across modalities.

Skeletal and dental data for subadult analyses obtained from dry bones or various types of medical images, such as computed tomography (CT) scans or conventional radiographs/x-rays, should be consistent and repeatable to ensure method applicability across modalities and support combining study samples. The present study evaluates observer agreement of epiphyseal fusion and dental development stages obtained on CT scans of a U.S. sample and the consistency of epiphyseal fusion stages between CT scans and projected scan radiographs/scout images (U.S. CT sample), and between dry bones and conventional x-rays (Colombian osteological sample). Results show that both intra- and interobserver agreements of scores on CT scans were high (intra: mean Cohen's kappa=0.757-0.939, inter: mean Cohen's kappa=0.773-0.836). Agreements were lower for dental data (intra: mean Cohen's kappa=0.757, inter: mean Cohen's kappa=0.773-0.0.820) compared to epiphyseal fusion data (intra: mean Cohen's kappa=0.939, inter: mean Cohen's kappa=0.807-0.836). Consistency of epiphyseal fusion stages was higher between dry bones and conventional x-rays than between CT scans and scout images (mean Cohen's kappa=0.708-0.824 and 0.726-0.738, respectively). Differences rarely surpassed a one-stage value between observers or modalities. The complexity of some ossification patterns and superimposition had a greater negative impact on agreement and consistency rates than observer experience. Results suggest ordinal subadult skeletal data can be collected and combined across modalities.

A method for estimating gestational age of fetal remains based on long bone lengths.

The estimation of gestational age (GA) in fetal human remains is important in forensic settings, particularly to assess fetal viability, in addition to often being the only biological profile parameter that can be assessed with some accuracy for non-adults. The length of long bone diaphysis is one of the most frequently used methods for fetal age estimation. The main objective of this study was to present a simple and objective method for estimating GA based on the measurements of the diaphysis of the femur, tibia, fibula, humerus, ulna, and radius. Conventional least squares regression equations (classical and inverse calibration approaches) and quick reference tables were generated. A supplementary objective was to compare the performance of the new formulae against previously published models. The sample comprised 257 fetuses (136 females and 121 males) with known GA (between 12 and 40 weeks) and was selected based on clinical and pathological information. All measurements were performed on radiographic images acquired in anonymous clinical autopsy records from spontaneous and therapeutic abortions in two Portuguese hospitals. The proposed technique is straightforward and reproducible. The models for the GA estimation are exceedingly accurate and unbiased. Comparisons between inverse and classical calibration show that both perform exceptionally well, with high accuracy and low bias. Also, the newly developed equations generally outperform earlier methods of GA estimation in forensic contexts. Quick reference tables for each long bone are now available. The obtained models for the estimation of gestational age are of great applicability in forensic contexts.

Skeletal age estimation in a contemporary Western Australian population using the Tanner-Whitehouse method.

Various age estimation techniques have been utilised in Australia to evaluate the age of individuals who do not have documentation to determine legal majority/culpability. These age estimation techniques rely on the assessment of skeletal development as visualised in radiographs, CT scans, MRI or ultrasound modalities, and subsequent comparison to reference standards. These standards are not always population specific and are thus known to be less accurate when applied outside of the original reference sample, leading to potential ethical implications. Therefore, the present study aims to: (i) explore the variation in developmental trajectories between the established Tanner-Whitehouse (TW) age estimation standards and a Western Australian population; and (ii) develop specific hand-wrist age estimation standards for the latter population. The present study examines digital anterior-posterior hand-wrist radiographs of 360 individuals 0 to 24.9 years of age, equally represented by sex. Each radiograph was assessed using the RUS, Carpal and 20-bone methods of Tanner et al. The standard error of the estimate (SEE) was calculated for each method (range: ♀ SEE ±0.4-11.5 years; ♂ SEE ±0.9-10.1 years). The most accurate method was TW3 RUS for females and the TW2 Carpal system for males. The 50th centile skeletal maturity scores for each year age group were plotted against average chronological age to produce polynomial regression standards with a demonstrated accuracy of (♀ SEE ±0.09-3.46 years; ♂ SEE ±0.02-3.42 years) for females and males, respectively. The standards presented here can be used in future forensic investigations that require age estimation of hand-wrist bones in a Western Australian population, however, they are not appropriate for establishing age of majority (18 years), as skeletal maturity was attained on average earlier than 15 years of age in both sexes for all three systems examined.

Developmental patterns of bilateral asymmetry in ancestral puebloans.

OBJECTIVES: Producing and maintaining a bilaterally symmetric phenotype throughout the lifespan is energetically demanding. Over the course of an individual's life, various intrinsic and external stressors impact the growth trajectory. These perturbations can compromise the allocation of energetic resources to processes that maintain developmental precision, potentially resulting in bilateral asymmetry (BA). Because different stressors are present during the lifespan, BA is a valuable tool for examining the unique factors impacting symmetrical growth and development. This study examines BA in paired long bones across a developmental skeletal series. METHODS: The humeri, radii, femora, and tibiae of 198 individuals from Ancestral Puebloan New Mexico (919-1670 CE) are analyzed to explore BA across development. Individuals are separated into five age categories, and by sex when possible, to explore patterns of BA. RESULTS: Significant BA is found in the bones of the upper limb when the interaction between bone and age is examined. Results suggest that BA in the humerus and radius becomes more right-biased with age. These directional trends are not observed in the lower limbs. Division into age categories illuminates patterns of asymmetry associated with age-related activities and physiological maturity, indicating that BA is differentially affected by varying environmental stressors across development. CONCLUSIONS: Our findings support the hypothesis that BA in long bones is influenced by environmental stressors that impact an individual's ability to produce symmetric morphological traits over the lifespan. Right-biased BA in the upper limb bones indicates that this variation from a symmetric ideal is strongly influenced by handedness resulting from habitual manual activities. Am. J. Hum. Biol. 28:421-430, 2016. © 2015 Wiley Periodicals, Inc.

Isometric Scaling in Developing Long Bones Is Achieved by an Optimal Epiphyseal Growth Balance.

One of the major challenges that developing organs face is scaling, that is, the adjustment of physical proportions during the massive increase in size. Although organ scaling is fundamental for development and function, little is known about the mechanisms that regulate it. Bone superstructures are projections that typically serve for tendon and ligament insertion or articulation and, therefore, their position along the bone is crucial for musculoskeletal functionality. As bones are rigid structures that elongate only from their ends, it is unclear how superstructure positions are regulated during growth to end up in the right locations. Here, we document the process of longitudinal scaling in developing mouse long bones and uncover the mechanism that regulates it. To that end, we performed a computational analysis of hundreds of three-dimensional micro-CT images, using a newly developed method for recovering the morphogenetic sequence of developing bones. Strikingly, analysis revealed that the relative position of all superstructures along the bone is highly preserved during more than a 5-fold increase in length, indicating isometric scaling. It has been suggested that during development, bone superstructures are continuously reconstructed and relocated along the shaft, a process known as drift. Surprisingly, our results showed that most superstructures did not drift at all. Instead, we identified a novel mechanism for bone scaling, whereby each bone exhibits a specific and unique balance between proximal and distal growth rates, which accurately maintains the relative position of its superstructures. Moreover, we show mathematically that this mechanism minimizes the cumulative drift of all superstructures, thereby optimizing the scaling process. Our study reveals a general mechanism for the scaling of developing bones. More broadly, these findings suggest an evolutionary mechanism that facilitates variability in bone morphology by controlling the activity of individual epiphyseal plates.

Make No Bones about It: Long Bones Scale Isometrically.

Long bones are far from being simple cylinders, so how is the relative positioning of their various features maintained during growth? A new study shows that growth is isometric and that drift from the correct position is minimized. Read the Research Article.

Ontogenetic changes in intralimb proportions in a Romano-Christian period sample from the Dakhleh Oasis, Egypt.

OBJECTIVES: The purpose of this study is to document the appearance of adult patterns in intralimb indices during ontogeny in a skeletal sample from the Kellis 2 cemetery, Dakhleh Oasis, Egypt. In addition, this study explores evolvability in intralimb indices to understand relative differences in sensitivity to ecogeographic variables. METHODS: Brachial and crural indices were compared across age cohorts with Welch's ANOVA tests and post-hoc Dunnett-Tukey-Kramer (DTK) pairwise multiple comparison tests. Spearman's rank correlation coefficients were used to examine developmental conservation and evolvability in intralimb proportions. RESULTS: Brachial and crural indices are greatest in the fetus/perinate cohort as compared to all other cohorts, decrease during infancy and early childhood, and increase during middle/late childhood. The adult pattern in the brachial index is first evident in infancy, but is not maintained throughout development. Conversely, the adult pattern in the crural index appears during early childhood and is maintained throughout development. The brachial index shows a higher degree of evolvability than the crural index in utero. CONCLUSIONS: The shifting pattern in intralimb proportions during development in the Kellis 2 sample is similar to that previously reported from globally diverse samples, which likely reflects the differential growth acceleration of proximal and distal intralimb skeletal elements during ontogeny. The brachial index may be more responsive to climatic conditions while the crural index may be more conserved due to functional demands. The data indicate that Kellis 2 juveniles were under strong selective pressures from climatic factors.

Ontogenetic changes in limb bone structural proportions in mountain gorillas (Gorilla beringei beringei).

Behavioral studies indicate that adult mountain gorillas (Gorilla beringei) are the most terrestrial of all nonhuman hominoids, but that infant mountain gorillas are much more arboreal. Here we examine ontogenetic changes in diaphyseal strength and length of the femur, tibia, humerus, radius, and ulna in 30 Virunga mountain gorillas, including 18 immature specimens and 12 adults. Comparisons are also made with 14 adult western lowland gorillas (Gorilla gorilla gorilla), which are known to be more arboreal than adult mountain gorillas. Infant mountain gorillas have significantly stronger forelimbs relative to hind limbs than older juveniles and adults, but are nonsignificantly different from western lowland gorilla adults. The change in inter-limb strength proportions is abrupt at about two years of age, corresponding to the documented transition to committed terrestrial quadrupedalism in mountain gorillas. The one exception is the ulna, which shows a gradual increase in strength relative to the radius and other long bones during development, possibly corresponding to the gradual adoption of stereotypical fully pronated knuckle-walking in older juvenile gorillas. Inter-limb bone length proportions show a contrasting developmental pattern, with hind limb/forelimb length declining rapidly from birth to five months of age, and then showing no consistent change through adulthood. The very early change in length proportions, prior to significant independent locomotion, may be related to the need for relatively long forelimbs for climbing in a large-bodied hominoid. Virunga mountain gorilla older juveniles and adults have equal or longer forelimb relative to hind limb bones than western lowland adults. These findings indicate that both ontogenetically and among closely related species of Gorilla, long bone strength proportions better reflect actual locomotor behavior than bone length proportions.

Comparison of bone age delay and recovery in Meyer dysplasia and Legg-Calvé-Perthes disease: a pilot study.

BACKGROUND: Meyer dysplasia (MD) is a rare disease but readily mistaken for Legg-Calvé-Perthes disease (LCPD). Although most published studies on MD have characterized and differentiated it from LCPD radiologically and clinically, differences with regard to bone age delay and recovery have not been sought. We deemed it necessary to distinguish bone age delay and recovery patterns between the two entities for better differentiation, prognostication, and parental advice. METHODS: Bone age delay and recovery of eight patients who were initially diagnosed with LCPD but were found to have MD were retrospectively reviewed and compared with those of age-matched patients with LCPD. Based on hand radiographs, the radius-ulna-short bones (RUSs) and carpal bone ages were determined using the Tanner and Whitehouse 3 (TW3) method. Minimum follow-up was 2 years (range 2-5 years). Differences in RUS and carpal bone ages and recovery patterns between the two entities were analyzed using trend lines in scatter plots. RESULTS: The mean delay of RUS bone age was significantly less in MD (0.52 ± 0.87 years) than in LCPD (1.11 ± 0.99 years). However, the difference between the mean carpal bone age delay in MD (1.13 ± 1.28 years) and LCPD (1.47 ± 1.19 years) was not significant. Trend lines showed faster bone age recovery patterns in MD than in LCPD. CONCLUSIONS: Bone age was delayed in both MD and LCPD but was less delayed in the former. RUS bone age showed more significant differences than carpal bone age when comparing the two entities and hence might be more useful for differentiating the two. Earlier bone age recovery patterns may be anticipated in patients with MD.

Improvement in growth after 1 year of growth hormone therapy in well-nourished infants with growth retardation secondary to chronic renal failure: results of a multicenter, controlled, randomized, open clinical trial.

BACKGROUND AND OBJECTIVES: Our aim was to evaluate the growth-promoting effect of growth hormone (GH) treatment in infants with chronic renal failure (CRF) and persistent growth retardation despite adequate nutritional and metabolic management. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: The study design included randomized, parallel groups in an open, multicenter trial comparing GH (0.33 mg/kg per wk) with nontreatment with GH during 12 months. Sixteen infants who had growth retardation, were aged 12+/-3 months, had CRF (GFR

Boys with a simple delayed puberty reach their target height.

INTRODUCTION: Final height in boys with delayed puberty is thought to be below target height. This conclusion, however, is based on studies that included patients with genetic short stature. We therefore studied final height in a group of 33 untreated boys with delayed puberty with a target height >-1.5 SDS. METHODS: Standing height, sitting height, weight and arm span width were measured in each patient. Final height was predicted by the method of Greulich and Pyle using the tables of Bailey and Pinneau for retarded boys at their bone age (PAH1) and the tables of Bailey and Pinneau for average boys plus six months (PAH2). RESULTS: Mean final height (175.8 +/- 6.5 cm) was appropriate for the mean target height (174.7 +/- 4.5 cm). The prediction method of Bailey and Pinneau overestimated the final height by 1.4 cm and the modified prediction method slightly underestimated the final height (-0.15 cm). CONCLUSION: Boys with untreated delayed puberty reach a final height appropriate for their target height. Final height was best predicted by the method of Bailey and Pinneau using the tables for average boys at their bone age plus six months.

Multiplier method for limb-length prediction in the upper extremity.

PURPOSE: Limb-length discrepancy occurs in both the upper and lower extremities. Methods of predicting discrepancies at skeletal maturity have generally focused on the lower limbs. Paley et al devised the multiplier method to predict lower-limb-length discrepancy at skeletal maturity. The purpose of this study was to generate a similar methodology applicable for the upper limb. METHODS: Using radiographic, clinical, and anthropologic databases, we divided humeral, radial, and ulnar lengths at skeletal maturity by the humeral, radial, and ulnar lengths at each age and for each percentile given. The multipliers for the radius, the ulna, and the humerus were compared with each other. The multipliers also were compared based on percentile, ethnic and racial group, nationality, and anthropologic data. RESULTS: The multipliers for the humerus, radius, and ulna were equivalent in all percentile groups, varying only by age and gender after 1 year of age. The multipliers of different national and racial groups also were the same. The upper-extremity multipliers calculated from anthropologic data were very similar. CONCLUSIONS: The multiplier method is a quick and easy method of predicting upper-limb growth. It is simpler to use than previous methods and is independent of percentile, generation, ethnicity, nationality, and race. The upper-extremity multiplier can be used to determine timing of epiphysiodesis and predict bone length at skeletal maturity, growth remaining, and congenital and developmental limb-length discrepancy. TYPE OF STUDY/LEVEL OF EVIDENCE: Prognostic II.