Lower Bones Research Articles

The lower jaw and dentition of the traversodontid Exaeretodon riograndensis Abdala, Barberena & Dornelles, from the Brazilian Triassic (Santa Maria 2 Sequence, Hyperodapedon Assemblage Zone)

Exaeretodon riograndensis Abdala, Barberena, & Dornelles, 2002 is the most abundant traversodontid preserved in the basal Santa Maria 2 Sequence (Hyperodapedon Assemblage Zone), southern Brazil and is closely related to Exaeretodon argentinus Cabrera, 1943 from the Ischigualasto Formation, Argentina. Previous anatomical studies of E. riograndensis have focused mainly on cranial material and little is known about the morphology of its lower dentition or postdentary bones. We describe the first fairly complete postdentary series of the mandible of E. riograndensis and provide additional information on its lower dentition. The postdentary bones of E. riograndensis include a complex coronoid, an angular with a delicate reflected lamina and a stout retroarticular process of the articular, contrasting with the morphology reconstructed for Argentinean specimens, which possess a small retroarticular process. Apart from that, the postdentary bones do not differ significantly from those known for E. argentinus, a fact expected due to the great similarity between other skeletal features of these species. Furthermore, the lower postcanines of E. riograndensis have virtually the same structure as those of E. argentinus, with an approximate quadrangular shape in occlusal view. Moreover, the transverse cusp row is placed anteriorly and comprises a lingual and a buccal cusp, and the occlusal basin delimited by the four main cusps is relatively deep. The new material does not add any taxonomically diagnostic features to E. riograndensis. However, the fossils greatly improve our understanding of the anatomy of the Brazilian species.

English

INTRODUCTION: Sirenomelia or “mermaid syndrome” represents a severe form of caudal regression. It is a rare congenital malformation that is incompatible with life1. In Greek mythology, the Sirens were three creatures with the head of a woman and the body of a bird from the wings down. They were dangerous to sailors, whom they narcotized with their enchanting music and voices to later kill them. Over time, these bird-women were portrayed as more aquatic creatures, and eventually with a full mermaid-like appearance2, 9. It is likely that creatures of classical and medieval mythology were inspired by the observation of real cases of human malformations and it is likely that Sirens were similarly inspired. However, despite the present perception of Sirens as romantic and cute creatures, the sirenomelia human malformation is a severe condition6. Ultrasound may be useful in the early antenatal detection of this anomaly. This is the first case of sirenomelia reported in the black race. Sirenomelia has been classified by Stoker and Heifetz into 3 types according to the number of lower limb bones present.

A comparison of the microarchitecture of lower limb long bones between some animal models and humans: a review

Animal models are unavoidable and indispensable research tools in the fields of bone tissue engineering and experimental orthopaedics. The fact that there is not ideal animal model as well as the differences in the bone microarchitecture and physiology between animals and humans are complicate factors and make model implementation difficult. Therefore, the tendency should be directed towards extrapolation of the results from one animal model to another or from animal model to humans. So far, this is the first paper which provides an overview on the microarchitecture of lower limb long bones and discusses data related to osteon diameter, osteon canal diameter and their orientation, as well as intracortical canals and trabecular tissue microarchitecture in commonly used animal models compared to humans depending on age, gender and anatomical location of the bone. Understanding the differences between animal model and human bone microarchitecture should enable a more accurate extrapolation of experimental results from one animal model to another or from animal models to humans in the fields of bone tissue engineering and experimental orthopaedics. Also, this should be helpful in making decisions on which animal models are the most suitable for particular preclinical testing.  

Fundamental ratios and logarithmic periodicity in human limb bones

Fundamental mathematical relationships are widespread in biology yet there is little information on this topic with regard to human limb bone lengths and none related to human limb bone volumes. Forty-six sets of ipsilateral upper and lower limb long bones and third digit short bones were imaged by computed tomography. Maximum bone lengths were measured manually and individual bone volumes calculated from computed tomography images using a stereologic method. Length ratios of femur : tibia and humerus : ulna were remarkably similar (1.21 and 1.22, respectively) and varied little (<7%) between individuals. The volume ratio of femur : tibia was approximately half that of humerus : ulna (1.58 and 3.28, respectively; P < 0.0001). Lower limb bone volume ratios varied much more than upper limb ratios. The relationship between bone length and volume was found to be well described by power laws, with R(2) values ranging from 0.983 to 0.995. The most striking finding was a logarithmic periodicity in bone length moving from distal to proximal up the limb (upper limb λ = 0.72, lower limb λ = 0.93). These novel data suggest that human limb bone lengths and volumes follow fundamental and highly conserved mathematical relationships, which may contribute to our understanding of normal and disordered growth, stature estimation, and biomechanics.

Prenatal diagnosed caudal regression syndrome

Background: Caudal regression syndrome (CRS) is a rare complex congenital anomaly which is characterized by agenesis of the sacral and lumbar spine. Pelvis, lower extremity, genitourinary, cardiac anomalies and lower extremity neurological and motor development deficits may be accompanied. The exact etiology is unclear but the maternal insulindependent diabetes mellitus (hyperglycaemia during embryogenesis seems to act as a teratogen), genetic factors, vascular hypoperfusion may play a role in the etiology. Case: A 41-year-old gravida 4, para 2, live 1, abortus 1 patient with 35 weeks of gestation. The patient had 12-year history of type 1 diabetes mellitus. In ultrasonographic examination we found the length of the bones (all the upper and lower bones) 8 weeks underdeveloped and didn’t observe the lumbar, sacral vertebrae and iliac bones. Lower extremities were crossed in froglike position, there wasn’t lower extremity movements. Due to sacral agenesia the head of the femurs were closer. Also pes equinovarum deformity, single umbilical artery, kidneys in contact at the midline were present. All of these findings indicated the diagnosis of caudal regression syndrome. Conclusion: Diabetes is increased fetal anomalities in pregnancy. Diabetic pregnancy should be more evaluated than pregnancies with no risk. Antenatal care should be done more carefully. Especially, prenatal maternal blood glucose levels and HbA1cis most important for prevention of fetal anomalities.

Entheseal Changes: Do They Reflect Socioeconomic Status in the Early Medieval Central European Population? (Mikulčice – Klášteřisko, Great Moravian Empire, 9th – 10th century)

ABSTRACTEntheseal changes (EC) of skeletons are supposed to reflect the physical activity of our ancestors. Similarly, the elements of the burial rite (e.g. grave goods, burial depth) are presumed to be related to the social status of individuals. The aim of this study was to verify the existence of relationships between EC distribution and archaeological descriptors providing information on social status.Fibrocartilaginous entheses of upper and lower limb bones of 115 individuals (aged 20–50 years) from the early medieval burial site Mikulčice – Klášteřisko were evaluated using Villotte's method (2006). Factor analysis (FA) was applied two times with two different combinations of descriptors: (i) FA‐1 based on the archaeological characteristics; (ii) FA‐2 based on the distribution of EC for males and females separately. The second step was important for the validation of results acquired from archaeological data.It is possible to link several models of EC distribution with selected archaeological characteristics. (i) The relationship between EC and archaeological descriptors is more visible in males than females. (ii) Males withwarrior equipmentand deep graves very probably belonged to the higher social class and are characterised by the loading of the triceps brachii on the olecranon and of the gluteus medius on the femur. (iii) Males with shallower graves and objects of daily use more typically demonstrate an occurrence of EC at the insertion site of the wrist flexors or extensors. The clear links demonstrated in males were absent in females. There exists only a weak relationship between the descriptorjewelleryand the incidence of EC at the insertion sites of the shoulder and certain insertion sites of the lower limbs (especially the hip rotators). This poorly significant relationship supports our previous hypothesis that females from Mikulčice performed the same activities regardless their socioeconomic status. Copyright © 2012 John Wiley &amp; Sons, Ltd.

Evaluation of embolic protection devices for fat emboli prevention.

Patients with acutely treated femoral shaft fractures with reamed intramedullary nailing are at risk for acute respiratory distress syndrome due to liberation of bone marrow fat particles that travel to the lung and cause damage to the parenchyma. The purpose of this study was to demonstrate: (1) the ability of clinically applicable embolic protection devices to capture such particles; (2) how such a device affects cardiopulmonary function after reamed intramedullary nailing; and (3) evaluation of lung pathology to determine whether filtration affects pulmonary embolic load. A total of 12 canines were anesthetized, and hemodynamic monitoring was established. Carotid embolic protection devices were introduced into the iliac vein, and ipsilateral intramedullary reaming and nailing was performed. Cardiopulmonary parameters were recorded at timed intervals up to 60 minutes after the procedure. The control group (n=4) was compared with groups treated with Accunet (n=4) and Spider (n= 4) filters. A blinded histopathological review was performed on lung specimens to determine the average number of emboli per section and to measure the area (mm(2)) of embolic load by digital image analysis. Gross inspection of the embolic protection devices showed the presence of bone marrow debris. A significant change was observed in pH levels (control= -0.052, filters=+0.005; P< .05) within the 60 minutes after intramedullary nailing. Serum bicarbonate (meq/dL) values were noted to have similar changes of -2.7 and -1.8 at 10 and 60 minutes, whereas the experimental group was+0.6 and+0.8 at the same time intervals (P=.01 and .0004, respectively). Pulmonary measurements for pO2 and oxygen saturation were analogous to the serum parameters with decreases in the control group in comparison with the filter groups. The mean numbers of emboli and area measurements of embolic load were significantly reduced in the filter group (all P< .01). Embolic protection devices were effective in capturing embolic debris from reamed intramedullary nailing of lower extremity long bones and demonstrated a protective effect on pulmonary function and significantly decreased the number and size of emboli in the lung. Based on these findings, patients with long bone fractures at risk for pulmonary complications and acute respiratory distress syndrome could benefit from the placement of embolic protection devices prior to intramedullary fixation. While this study utilized filtration devices designed for carotid embolic protection, further study is warranted to determine optimal filter design in this setting.

Soft-plastic brace for lower limb fractures in patients with spinal cord injury

Retrospective study at a rehabilitation center. Patients with spinal cord injury, even if they are wheelchair users, sometimes suffer from fractures of the lower limb bones. As their bones are too weak to have surgery, and because a precise reduction is not required for restoration, such patients are often indicated for conservative treatment. This case series study investigated the use of a hinged, soft-plastic brace as a conservative approach to treating fractures of the lower extremities of patients with spinal cord injury. National Rehabilitation Center, Japan. Fifteen patients (male, n=10; female, n=5; average age, 52.7 years) with 19 fractures of the femur or the tibia who were treated with a newly-developed hinged, soft-plastic brace were studied. All of them used wheelchairs. We analyzed the time taken for fracture union and for wearing orthotics, degree of malalignment, femorotibial angle and side effects. The fractures in this series were caused by relatively low-energy impact. The average time taken for fracture union was 80.1 (37-189) days, and the average amount of time spent wearing orthotics was 77.9 (42-197) days. On final X-ray imaging, the average femorotibial angle was 176.9° (s.d. ±8.90), and 15° of misalignment in the sagittal plane occurred in one patient. A hinged, soft-plastic brace is a useful option as a conservative approach for treating fractures of the lower extremities in patients with spinal cord injury.

Local ecological profile for Paranthropus robustus in South Africa using stable carbon isotopes from associated bovid teeth

The biomechanical characterization of lower limb long bones in the chrono-ecogeographically diverse species Homo erectus is a fundamental step for assessing evolutionary changes in locomotor mode and body shape that occurred within the genus Homo. However, the samples available for the Early and earlier Middle Pleistocene are small and widely scattered in time and space, thus limiting our understanding of the nature and polarity of morphological trends. Compared to the African fossil record, loading histories based on detailed biomechanical assessment of diaphyseal strength in Indonesian H. erectus lower limb long bones have not been assessed. By using a microtomographic record (μCT), we performed a quantitative analysis of the biomechanical properties and structural organization of Kresna 11, a late Early Pleistocene adult H. erectus femoral shaft from the Sangiran Dome, Central Java. Relative to the modern human condition, Kresna 11 shows the predominant mediolateral cortical thickening (hypertrophy) and the distal displacement of the minimum diaphyseal breadth characteristic of early Homo femora, associated nonetheless with relatively modest cortical thickness within the mid-proximal portion. Synthetic functional imaging of the shaft through the planar representation of its inner structure has revealed distal thickening of the medial cortex, a feature previously unreported in H. erectus. The increase in relative mediolateral bending strength observed in Kresna 11 supports the hypothesis that, rather than simply reflecting differences in patterns of locomotor loading, biomechanical properties of the femoral shaft in archaic Homo are strongly influenced by body shape, i.e., variations in pelvic breadth and femoral neck length.

Skeletal and Surgical Evidence for Acute Osteomyelitis in Non‐Adult Individuals

AbstractOsteomyelitis is a non‐specific infection of the bone and bone marrow. In the past acute osteomyelitis (AO) led to high mortality especially in non‐adults. Nevertheless, its diagnosis in archaeological populations is rare. Documented individuals with known cause of death offer a unique opportunity to study this condition. This article aims to describe the bone lesions in non‐adults diagnosed with AO at the Coimbra University Hospital (CUH) and now belonging to the Coimbra Identified Skeletal Collection (CISC). Moreover, mortality rates and demographic profiles for individuals aged ≤18 years old and diagnosed with AO in the CUH, between 1923 and 1929, were also determined. The 5 (1%) non‐adults in the CISC with AO listed as cause of death were selected for this study, and their bones were analysed macroscopically and radiologically. The skeletal remains of one individual revealed a small area of new bone formation in the shaft of the left femur. Radiography of this bone showed a radio‐opaque area in the diaphysis. The other four individuals show evidence of surgical treatment, responsible for many cases of disability in the past. In the 7‐year period under analysis, 122 juveniles were diagnosed with osteomyelitis and admitted for surgery at the CUH, 43 (35.2%) of which were diagnosed with AO. Sixty‐five per cent of the cases of AO occurred between the ages of 8 and 15 years, with boys twice as frequently affected as girls, and lower limb bones were involved in 91% of AO cases. AO was responsible for 76.9% of the deaths. This study of pre‐antibiotic non‐adults may help to recognize skeletal signs of AO and their surgical treatment in unidentified skeletal remains. Copyright © 2012 John Wiley &amp; Sons, Ltd.

Skeletal changes in lower limb bones in domestic cattle from Eketorp ringfort on the Öland island in Sweden

In this paper the nature and frequency of skeletal changes in the lower limb bones of cattle are investigated. The bones derive from the archaeological site of Eketorp ringfort on the Öland island in Sweden dated between Iron Age–Middle Age (ca. A.D. 300–1200/50). The analysis was conducted to explore whether skeletal lesions were associated with traction activity, and if changes in the type and prevalence of lesions occurred over time. Different skeletal lesions were recorded by bone and precise anatomical location: the joint surfaces of metapodia and phalanges were divided into four to seven zones to determine if different types of lesions were located on particular regions of the articular surface. The results show that metatarsals exhibited a higher frequency of pathologies in the Iron Age and medieval period compared to metacarpals, while anterior phalanges 1 and 2 had a higher occurrence of lesions than the posterior elements. The study also demonstrates that the type and location of depressions on joint surfaces are unevenly distributed between bone elements. Finally, the results show that skeletal lesions were more common in robust animals.

Structural analysis of the Kresna 11 Homo erectus femoral shaft (Sangiran, Java)

The biomechanical characterization of lower limb long bones in the chrono-ecogeographically diverse species Homo erectus is a fundamental step for assessing evolutionary changes in locomotor mode and body shape that occurred within the genus Homo. However, the samples available for the Early and earlier Middle Pleistocene are small and widely scattered in time and space, thus limiting our understanding of the nature and polarity of morphological trends. Compared to the African fossil record, loading histories based on detailed biomechanical assessment of diaphyseal strength in Indonesian H. erectus lower limb long bones have not been assessed. By using a microtomographic record (μCT), we performed a quantitative analysis of the biomechanical properties and structural organization of Kresna 11, a late Early Pleistocene adult H. erectus femoral shaft from the Sangiran Dome, Central Java. Relative to the modern human condition, Kresna 11 shows the predominant mediolateral cortical thickening (hypertrophy) and the distal displacement of the minimum diaphyseal breadth characteristic of early Homo femora, associated nonetheless with relatively modest cortical thickness within the mid-proximal portion. Synthetic functional imaging of the shaft through the planar representation of its inner structure has revealed distal thickening of the medial cortex, a feature previously unreported in H. erectus. The increase in relative mediolateral bending strength observed in Kresna 11 supports the hypothesis that, rather than simply reflecting differences in patterns of locomotor loading, biomechanical properties of the femoral shaft in archaic Homo are strongly influenced by body shape, i.e., variations in pelvic breadth and femoral neck length.

Basic consideration of research strategies for head and neck cancer

Head and neck cancer (HNC) consists of a group of malignancies affecting closely related anatomical regions of the upper aerodigestive tract (UADT), including the oral cavity, salivary glands, upper and lower jaw bones and facial skin; the nasal cavity, paranasal sinuses, pharynx, larynx and thyroid gland (although the latter is often excluded and considered as part of endocrine neoplasms). Of these, 90% of HNCs are histologically squamous cell carcinomas originating from the mucosal lining. These malignancies are strongly associated with certain environmental and life-style risk factors, principally tobacco in both smoked and smokeless forms, excessive alcohol consumption, diets poor in antioxidants and essential micronutrients, UV light, chemicals used in certain workplaces, and viruses, principally certain strains of human papillomavirus (HPV) and Epstein-Barr virus (EBV). These cancers are frequently aggressive in their biological behaviour with local invasion and metastasis to lymph nodes in the neck. Since most patients are already at late stages of disease at the time of diagnosis, the desirable practice of early diagnosis (first sign of the malignant lesion at an initial stage) and early treatment, a critical priority to save lives and retain quality of life, is difficult to implement. Thus, primary prevention has been set as a key goal. This article aims to reinforce the basic knowledge of aetiology, key risk factors related to the development of head and neck cancer, basic features of clinical appearance of this group of cancers, and strategies for prevention and early detection.We also suggest basic research strategies on the basis of current knowledge, which should ultimately lead to the improvement of clinical management.

The prosthetic rehabilitation of a panfacial fracture patient after reduction: A clinical report

Panfacial fractures involve trauma to the lower, middle, and upper facial bones and often require a team approach for management. Early and complete restoration of preinjury facial contours and function should be the goal of the oral and maxillofacial surgeon and the prosthodontist. When the intraoral landmarks are lost, overall facial anatomic landmarks can be used to restore the oral cavity. A patient with complex clinical panfacial fractures, including a vertically and horizontally malpositioned native alveolar bone and severe facial asymmetry, is presented. A functional and esthetic rehabilitation was successfully accomplished by using a partial removable dental prosthesis retained with telescopic crowns and magnetic attachments in the maxilla and osseointegrated implants to support a definitive dental prosthesis in the mandible.

A method for estimating age of Danish medieval sub-adults based on long bone length

The preferred method for aging archaeological sub-adult skeletons is by dental examination. In cases where no dental records are available, age estimation may be performed according to epiphyseal union, skeletal elements or diaphyseal lengths. Currently no data have been produced specifically for aging archaeological Danish sub-adults from the medieval period based on diaphyseal lengths. The problem with using data on Danish samples, which have been derived from a different population, is the possibility of skewing age estimates. In this study 58 Danish archaeological sub-adults were examined, aged from approximately six years to twenty-one years. The samples were aged according to two dental methods: Haavikko and Ubelaker. Regression formulae were constructed for aging according to their diaphyseal lengths both for individual long bones and combinations of upper and lower long bones. This study indicated that with the regression formulae developed, estimation of age can be done with reasonable results on Danish sub-adults. The Danish data were then compared to data from a different archaeological sample and a modern sample. It showed that the modern data indicated a consistently lower age compared to this sample which increased until reaching a maximum of nearly five years and six months. When comparing the archaeological data to this study, the growth profile crossed over at 12.5 years with a maximum age difference before the cross point of two years and three months lower for the archaeological data. After the cross point there was a maximum difference of three years and four months higher for the archaeological data. This study has shown the importance of using data for age estimation for archaeological material which has been developed specifically for that population. In addition it has presented a possible solution for Danish sub-adult material when dental material is not available.

The effect of partial weight bearing in a walking boot on plantar pressure distribution and center of pressure

Physicians routinely prescribe partial weight bearing in a walking boot following fractures of the lower limbs in order to produce the needed mechanical environment to facilitate healing. Plantar pressure measurements can provide key information regarding the mechanical environment experienced by lower limb bones. The effect of walking boots on plantar pressure distribution has been well reported, however, the combined effects of partial weight bearing and walking boots on plantar pressure distribution and center of pressure is unknown. Thirteen healthy volunteers with no known gait pathologies were fitted with a multi-pressure sensor insole that recorded their plantar pressure distribution during four walking trials: (i) normal walking, (ii) full weight bearing in a walking boot, (iii) 27kg partial weight bearing in a walking boot and (iv) 9kg partial weight bearing in a walking boot. Results demonstrated that changing from trial (i) to (iv) resulted in a posterior shift in weight distribution; the percentage of total weight experienced at the heel increased while the percentage of total weight experienced at the forefoot (both medial and lateral) and the hallux decreased. Center of pressure trajectories also shifted more posteriorly. Additionally, while in a walking boot the gait during full and partial weight bearing resulted in more even foot loading.

Habitual levels of high, but not moderate or low, impact activity are positively related to hip BMD and geometry: Results from a population-based study of adolescents

Whether a certain level of impact needs to be exceeded for physical activity (PA) to benefit bone accrual is currently unclear. To examine this question, we performed a cross-sectional analysis between PA and hip BMD in 724 adolescents (292 boys, mean 17.7 years) from the Avon Longitudinal Study of Parents and Children (ALSPAC), partitioning outputs from a Newtest accelerometer into six different impact bands. Counts within 2.1 to 3.1g, 3.1 to 4.2g, 4.2 to 5.1g, and >5.1g bands were positively related to femoral neck (FN) BMD, in boys and girls combined, in our minimally adjusted model including age, height, and sex (0.5–1.1g: beta = −0.007, p = 0.8; 1.1–2.1g: beta = 0.003, p = 0.9; 2.1–3.1g: beta = 0.042, p = 0.08; 3.1–4.2g: beta = 0.058, p = 0.009; 4.2–5.1g: beta = 0.070, p = 0.001; >5.1g: beta = 0.080, p < 0.001) (beta = SD change per doubling in activity). Similar positive relationships were observed between high-impact bands and BMD at other hip sites (ward's triangle, total hip), hip structure indices derived by hip structural analysis of dual-energy X-ray absorptiometry (DXA) scans (FN width, cross-sectional area, cortical thickness), and predicted strength (cross-sectional moment of inertia). In analyses where adjacent bands were combined and then adjusted for other impacts, high impacts (>4.2g) were positively related to FN BMD, whereas, if anything, moderate (2.1–4.2g) and low impacts (0.5–2.1g) were inversely related (low: beta = −0.052, p = 0.2; medium: beta = −0.058, p = 0.2; high: beta = 0.137, p < 0.001). Though slightly attenuated, the positive association between PA and FN BMD, confined to high impacts, was still observed after adjustment for fat mass, lean mass, and socioeconomic position (high: beta = 0.096, p = 0.016). These results suggest that PA associated with impacts >4.2g, such as jumping and running (which further studies suggested requires speeds >10 km/h) is positively related to hip BMD and structure in adolescents, whereas moderate impact activity (eg, jogging) is of little benefit. Hence, PA may only strengthen lower limb bones in adolescents, and possibly adults, if this comprises high-impact activity. © 2012 American Society for Bone and Mineral Research.

Erdheim–Chester disease associated with intramedullary spinal cord lesion

Erdheim-Chester disease (ECD) is a rare non-Langerhans cell histiocytosis. We present a case of a 56-year-old male with ECD. As time progressed, involvement of the orbital fossa, cranial convexity, spinal cord, brain stem, thyroid, lung, retroperitoneum, lower extremity bones and skin were found. Previously reported cases reveal the frequency of ECD with spinal cord involvement is rare. Although this was a presumed diagnosis based on other lesions, our case is the first in which both intramedullary and epidural masses are present.

Development of fetal trabecular micro‐architecture in the humerus and femur

It is widely accepted that during postnatal development trabecular bone adapts to the prevailing loading environment via modelling. However, very little is known about the mechanisms (whether it is predominantly modelling or remodelling) or controls (such as whether loading influences development) of fetal bone growth. In order to make inferences about these factors, we assessed the pattern of fetal trabecular development in the humerus and femur via histomorphometric parameter quantification. Growth and development (between 4 and 9 months prenatal) of trabecular architecture (i.e. thickness, number and bone volume fraction) was compared across upper and lower limb bones, proximal and distal regions, and sexes. The data presented here indicate that during prenatal development trabeculae became thicker and less numerous, whilst bone volume fraction remained constant. This partly mimics the pattern of early postnatal development (0-2 years) described by other researchers. Thickness was reported to increase whilst number reduced, but bone volume fraction decreased. This is perhaps because the balance of bone modelling (deposition vs. resorption) changes post partum. Published histological data suggest that bone deposition slows after birth, while resorption rates remain constant. Hence, fetal development may be characterized by relatively high rates of modelling and, particularly, bone deposition in comparison to postnatal. With respect to measures of thickness, number and bone volume fraction prenatal development was not bone, site, or sex specific, whilst postnatally these measures of architecture diverge. This is despite reported developmental variation in the frequency, speed and amplitude of fetal movements (which begin after 11 weeks and continue until birth), and probably therefore loading induced by muscular contractions. This may be because prenatal limb bone micro-architecture follows a generalised predetermined growth trajectory (or genetic blueprint), as appears to be the case for gross distribution of trabecular tissue.

Comparison of Bipedal Walking between Early Hominids and Apes from a View Point of Lower Limb Bones Morphology

Comparison of Bipedal Walking between Early Hominids and Apes from a View Point of Lower Limb Bones Morphology