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Growth and development
Published in Jagdish M. Gupta, John Beveridge, MCQs in Paediatrics, 2020
Jagdish M. Gupta, John Beveridge
The mandible grows faster than the rest of the face at puberty. Elongation of long bones occurs both at primary and secondary ossification centres. With maturity the cartilage is replaced by ossified bone. Androgens accelerate bone maturation and stimulate osteogenesis, which results in epiphyseal fusion and ultimate diminution of linear growth. The lower femoral epiphysis is present at birth whereas the upper femoral epiphysis appears in the first year of life.
The skeleton and muscles
Published in Frank J. Dye, Human Life Before Birth, 2019
By the end of the embryonic period, primary ossification begins in the diaphyses (shafts) of the long bones. After birth, secondary ossification centers appear in the epiphyses (ends) of these bones. As long as cartilage (in the form of epiphyseal plates) persists in the ends of the long bones between the ossification centers, growth continues. The persistence of epiphyseal plates provide for interstitial growth in the length of the long bones, whereas the periosteum provides for appositional growth in the girth of these bones. With adolescence, elevated sex steroid levels cause both epiphyseal fusion of the ossification centers and cessation of the long bones’ growth.
Clinical anatomy of the newborn
Published in Prem Puri, Newborn Surgery, 2017
Mark D. Stringer, S. Ali Mirjalili
Of the 800 or so ossification centers in the human skeleton, just over half appear after birth; these include most secondary ossification centers (Figure 3.8). Cartilage is abundant at birth; none of the carpal bones have ossification centers. The only secondary centers of ossification in the long bones at birth are in the femoral and tibial condyles and sometimes in the humeral head.26 The iliac crest, acetabular floor, and ischial tuberosity are all cartilaginous.
Determining the development stage of the ossification centers around the elbow may aid in deciding whether to use ESIN or not in adolescents’ forearm shaft fractures
Published in Acta Orthopaedica, 2021
Markus Stöckell, Tytti Pokka, Nicolas Lutz, Juha-Jaakko Sinikumpu
In addition to the olecranon ossification center, we found that the other 3 ossification centers, trochlea, lateral humeral condyle, and proximal radial head, were also associated with impaired union. This is reasonable, while all secondary ossification centers develop in a particular order and thus are related to bone age. However, although associated with impaired union, the other ossification centers had lower statistical variables when compared with the olecranon. From a clinical point of view, these other ossification centers may support the clinician as well, when he/she is considering the maturation stage of the patient’s skeleton. Our finding regarding other ossification centers is different from that of the report by Morrison et al. (2020), which is the only previous study of the issue. They reported on only the olecranon apophysis and its association with inferior results of ESIN in childhood forearm shaft fractures. In their study, olecranon stage > 3 (on the scale 1–7) was associated with increased complications in bone healing. In our study, the optimal cutoff point was higher: no patient presented disturbed healing if the olecranon development status was between 1 and 5. However, there was a difference in determining low-quality fracture healing between the studies: Morrison et al. used 6 months of impaired healing as nonunion, while the respective time was 12 months in our study.
Micro-architecture study of the normal odontoid with micro-computed tomography
Published in The Journal of Spinal Cord Medicine, 2020
Wei Wang, Zhijun Li, Yingna Qi, Lianxiang Chen, Ping Yi, Feng Yang, Xiangsheng Tang, Mingsheng Tan
This similarity suggests that the characteristics is occurring in ossification centers of the odontoid. Development of the axis involves ossification of four ossification centers consisting of the vertebral body and the odontoid. The odontoid process fuses to the vertebral body at 3–6 years of age. As even normal odontoid ossification centers may not be completely fused until young adolescence, however, normal areas of incomplete fusion may be mistaken for fractures.18 We also noted, with micro-CT, that the ossification center formed a trabecular cavity in one of the specimens. The micro-architecture of the ossification center of the odontoid was thus markedly altered compared with normal trabeculae bone (Fig. 4). The ossification center was interspersed with areas devoid of the trabecular cavity that had lower bone volume fractions and thus represented weak points in the structure. Because of an absence of the range of completed trabeculae due to resorption in the ossification center, the base of the odontoid-responsible for its load-bearing capacity-might thus have been weakened.
Epidermal growth factor signalling pathway in endochondral ossification: an evidence-based narrative review
Published in Annals of Medicine, 2022
L. Mangiavini, G. M. Peretti, B. Canciani, N. Maffulli
To better understand the role of EGF signalling in postnatal growth, a rescue experiment was performed [105,106]. In this study, a conditional knock-in mouse model for human EGFR was bred with Egfr-\- mice to analyse the effects of lower levels of EGFR in different tissues, as the rescue was only partial. In long developing bones, the hypertrophic chondrocyte layer was expanded, probably from a delay in the formation of the primary ossification centre. Moreover, the culture of primary osteoblasts was characterised by decreased proliferation; conversely, differentiation was promoted [105,106].