Ossification Centers Research Articles

The Ulnar Olecranon-Coronoid Notch Angle Affects Terminal Elbow Extension in Children and Adolescents.

Limitations to terminal elbow extension (TEE) in pediatric populations have been commonly associated with the degree of ligamentous laxity and not bony factors. Ligamentous laxity, quantified through the Beighton score, is criticized for unreliably assessing joint mobility. This study aims to show that the olecranon-coronoid notch angle (OCNA) affects TEE in healthy children and adolescents. A retrospective study of 711 pediatric patients treated for upper extremity and shoulder injuries was cross-sectionally studied at 2 tertiary centers from 2014 to 2021. Radiographs were used to measure the OCNA, humerocondylar angle, proximal anterior ulnar angle, and the presence of secondary centers of ossification. A 2-axis goniometer measured clinical TEE to a firm endpoint. The statistical analysis studied the relationships between OCNA and TEE and the effect that age and sex have on these measurements. Increased TEE was associated with increased OCNA (P<0.001) when accounting for age and sex. The average OCNA was 30.0 degrees (7.5 degrees), and the average TEE was 5.6 degrees (8.0 degrees). There was a difference in OCNA between subjects who had elbow hypoextension, normal TEE, and elbow hyperextension (P<0.001). The most common injuries were distal radius fractures (182, 26%), elbow sprains and contusions (111, 16%), distal both bone forearm fractures (95, 14%), single or both bone shaft fractures (77, 11%), and supracondylar fractures (74, 11%). These results show that the orientation of the opening of the olecranon-coronoid notch influences the arc of TEE motion in a healthy pediatric population. The notch restrains TEE by activating the bony block mechanism between the olecranon apophysis and the olecranon fossa. The measurement of the OCNA can serve as a reproducible and quantitative method to predict hypomobility to hypermobility of TEE motion. Prognostic study: Level II.

Posterior femoral condylar separation: Is it a particular type of osteochondritis dissecans in adolescents?

Introduction. Dissecting osteochondritis (RO) is based on damage to the subchondral bone, leading to its detachment and sequestration separately or together with articular cartilage with the possible formation of a free bone-cartilage fragment. The disease occurs more often in adolescents, accompanied by an increased risk of early arthrosis of the knee joint. Chronic traumatization of the subchondral bone leads to insufficient blood supply to a certain area of the growth zone of the secondary point of ossification of the femoral epiphysis, to ischemia and subsequent necrosis of the subchondral bone, which, according to modern literature, is the leading cause of the formation of the lesion. The typical localization of the RO focus is the lateral part of the medial condyle of the femur along the supporting surface. The present clinical analysis presents cases of atypical localization of dissecting osteochondritis with clinical features, specific signs on MRI, as well as various tactical approaches to treatment.Material and methods. This clinical review presents 3 cases of sequestration of the posterior lateral condyle of the femur in adolescents. Despite the similarity of the clinical picture and the MRI data, the features of the foci of RO were found in all children, which determined the need for an individual approach to therapeutic tactics. All children required surgical treatment, which was performed in the Department of Traumatology and Orthopedics of the N.F. Filatov DGKB in different volumes in each case: from transchondral osteoperforations and fixation of an osteochondral fragment with a screw to debridement of a fragmented focus with removal of osteochondral fragments.Results. All 3 clinical cases are united by atypical localization of the focus in the posterior lateral condyles of the femurs, the clinical course of the disease in the form of a low-intensity long-term pain syndrome, as well as the results of MRI of the knee joint. Most researchers adhere to the classical multifactorial etiological theory of dissecting osteochondritis, according to which the main mechanism of the origin of the lesion is mechanical overload of the subchondral bone with subsequent disruption of blood supply in it at the border with the secondary point of ossification of the femoral epiphysis. However, there is also data in the literature on congenital ossification disorder in the cartilaginous part of the growth zone of the secondary ossification point as the morphological basis of dissecting osteochondritis. The presented clinical cases cast doubt on the generally accepted model of primary damage to the subchondral bone as the only possible cause of the formation of the focus of RO, since patients have, among other things, signs of impaired ossification of the secondary ossification point of the femoral condyle, in one of whom a violation of ossification of the secondary ossification center was also determined in the patella in the form of patella bipartita.Conclusion. Inspite of all similarities connecting these cases there is still lack of data to judge about separate type of the OCD because every separate type of disease usually have particular morphological basis. There is a need of partial biopsy of these lesions to confirm or refute our hypothesis of posterior condylar separation being separate type of OCD. However these cases undoubtedly require particular managementwith special attention to timing of appropriate diagnostic procedures and surgical management to perform in time prior to osteochondral fragment separation. In case of the absence of any complaintswith particular MRI appearance of fragmented bone in the lesion with impaired ossificationindividual treatment planneeds to be defined.

Diagnostic accuracy of phone messaging forwarded images for developmental dysplasia of the hip

Objectives: The objectives of this study were to evaluate the accuracy of the diagnosis based on the phone forwarded pelvic radiographs for developmental dysplasia of the hip (DDH) and whether to accept decisions based on phone images. Methods: Two hundred and eight pelvic radiographs (416 hips) performed for DDH screening were evaluated by three orthopedic surgeons on picture archiving and communication system (PACS) and re-evaluated by the same surgeons after receiving them blindly on their phones through the WhatsApp application. Phone pictures were evaluated on both portrait and landscape viewing interfaces. Results: Nine ossification centers (2.9%) were detected on PACS but were not noticed when evaluated on the phone due to the lower phone image quality. All dislocated and dysplastic hips were correctly diagnosed by the phone. The phone overestimated the acetabular index by about two degrees, which explains why 4.8% and 7.5% of normal hips on PACS viewers were labeled dysplastic once evaluated on phone portrait and landscape viewers, respectively. However, landscape phone viewing and smaller phone screens were associated with a higher overestimation of the acetabular index. Conclusion: The phone is a valuable and safe tool for diagnosing DDH from pelvic radiographs. However, a precaution should be taken in borderline cases as the phone overestimated hip angles resulting in a misdiagnosis of normal hips as dysplastic. However, we do not recommend or encourage this practice because clinical evaluation is essential in any clinical decision-making.

Os Navicular Syndrome: A Symptomatic Accessory Ossicle of the Foot

Accessory navicular bone occurs due to failure of fusion of a secondary ossification center with the navicular. It is the second most common ossicle of the foot, with majority of them being identified incidentally on imaging studies. We report a case of 45-year-old female who presented with complaints of pain and localized redness over the medial aspect of the right foot which was aggravated on walking. This brief review aims to describe the pathophysiology, radiographic findings and management of Os naviculare syndrome. We also wish to highlight to the physicians that it must be suspected in patients with localized painover the medial aspect of the midfoot without obvious trauma. The presence of accessory navicular should not be disregarded as an incidental radiological variant in a symptomatic patient.

Teratogenic Evaluation of 80% Ethanol Extract of Embelia schimperi Vatke Fruits on Rat Embryo and Fetuses.

Introduction Embelia schimperi Vatke (family Myrsinaceae) is a commonly consumed anthelminthic plant in Ethiopia. The plant has significant efficacy in treating intestinal worms. However, there are limited data about the safety/toxicity of the plant. Moreover, the teratogenic effect of the plant is not yet well studied despite significant number of Ethiopian mothers consuming herbal medication during their pregnancy. Purpose This study aimed to evaluate the teratogenic effect of the hydroalcoholic extract of E. schimperi fruit on rat embryos and fetuses. Methods Pregnant albino Wistar rats were treated with 80% hydroalcoholic fruit extract of E. schimperi at 250 mg/kg, 500 mg/kg, and 1000 mg/kg dosage, whilst the controls were pair-fed and ad libitum groups. Maternal food intake, maternal weight gain, number of implantations, number of prior resorptions, fetal viability, fetal weight, fetal and embryonic crown-ramp length, placental weight, placental gross morphology and histopathology of placental tissue, number of somites, embryonic system, gross/visceral morphological malformations, and ossification centers were evaluated as teratogenicity indices. Results The crude extract of E. schimperi did not exhibit a significant difference in most developmental indices including the development of a circulatory system, nervous system, and musculoskeletal systems among treated animals and the controls. However, histopathological evaluation of placentas from the treatment groups showed that inflammatory reactions and calcifications compared to the pair-fed and ad libitum controls. Conclusion Administration of the 80% hydroalcoholic extract of E. schimperi fruit during the period of organogenesis in rats did not show a significant toxic effect on embryonic and fetal developmental indices. However, it might affect the structural integrity of the placenta as it is evidenced by inflammatory reactions and calcifications of decidua basalis of rat placenta.

Determination of age by radiological examination of shoulder joint

Aim of the study was to estimate the age of an individual from the fusion of the secondary ossification center of the shoulder joint. The study was conducted on 60 subjects who were randomly selected from various schools as well as the cases attending the outpatient Department of General Medicine, Rajiv Gandhi Government General Hospital, Madras Medical College, Chennai. After obtaining written consent from each individual, radiological examination was done. After the statistical analysis it was observed that in the age group 16-17 males, there were no complete union, among females in the same age group. It was 30%, in the age group 17-18, percentage of complete union was 30.76 among males and 40% among females, in the age group 18-19, percentage of complete union was 33.33% among males and 50% among females.It was concluded that the age of complete fusion of epiphysis of the shoulder joint was 17-18 years for males and 16-17 years for females and the earliest union occurred at the age of 15 years in females and 17 years in males which was higher than the previous studies

Mesenchymal cell-derived Wnt1 signaling regulates subchondral bone remodeling but has no effects on the development of growth plate or articular cartilage in mice.

Chondrocyte differentiation is a principal progress in endochondral ossification and in the formation of secondary ossification center (SOC) during the long bone development. We have previously reported that targeted deletion of Wnt1 in mesenchymal progenitors (Wnt1Prrx-/-) leads to spontaneous fractures and severe osteopenia in mouse long bones, suggesting that Wnt1 is a key regulator of bone metabolism. However, the effect of Wnt1 on the regulation of cartilage development and chondrocyte differentiation remained unknown. In this study, WNT1 protein expression was observed in lateral superficial cartilage and growth plate pre-hypertrophic chondrocytes in mice. Wnt1 mRNA expression was detected in epiphyseal cartilage from E16.5 to 3month-old mice. Detailed histological analyses revealed that the average thickness and chondrocyte density of proximal tibial articular cartilage and growth plate were unchanged between Wnt1Prrx-/- and control mice. However, μCT analysis of tibial epiphyses showed that the subchondral bone mass was reduced in Wnt1Prrx-/- mice compared to control mice, as demonstrated by decreased bone volume, trabecular number, trabecular thickness, and increased trabecular separation in Wnt1Prrx-/- mice. Mechanistically, histomorphometric analyses showed that the reduced subchondral bone mass in Wnt1Prrx-/- mice was due to impaired bone formation and enhanced bone resorption. In vitro, exogenous Wnt1 inhibited chondrogenesis and chondrocyte hypertrophy in both cell autonomous and juxtacrine manners, while matrix mineralization and the expression of Mmp13, Mmp9 and Opn were induced in a juxtacrine manner. Taken together, mesenchymal cell-derived Wnt1 is an important regulator of subchondral bone remodeling, although it has no effect on the regulation of growth plate or articular cartilage.

Interference Screw vs Suture Button Fixation for Tibialis Anterior Tendon Transfer to Lateral Cuneiform: A Biomechanical Analysis with Implications for Clubfoot Treatment

Category: Other Introduction/Purpose: While transfer of the tibialis anterior tendon (TAT) to the lateral cuneiform (LC) following serial casting has been used for over 60 years to treat relapsed clubfoot deformity, modern methods of tendon fixation remain largely unstudied. Though interference screw fixation has the potential of obviate concerns of pressure necrosis and proper tendon tensioning associated with plantar button suspensory stabilization, a better understanding of LC morphology in young children is a necessary first step in assessing the viability of this fixation technique. The purpose of this investigation is therefore to define LC morphology in children aged 3-6 years. Methods: A retrospective radiographic review of 40 healthy pediatric feet aged 3-6 years who had either MRI or CT scans was performed at a single pediatric hospital. The length, width, and height of only the ossified portion of the LC were measured digitally using sagittal, coronal, and axial imaging. In addition, the maximal cross-sectional diameter of the TAT was measured at the level of the tibiotalar joint. Results: Average ossified LC width ranged from 8.5mm in the 3-year-old cohort to 10.3mm in 6-year-old children. While the average width increased with each year of age, ANOVA testing revealed no statistically significant difference in width between age groups (p=0.091). Average ossified LC length ranged from 13.5mm in the 3-year-old cohort to 18.3mm in 6-year-old children with statistically significant increases in all age groups separated by two or more years (p=0.017). the TAT to ossified LC width ratio ranged from 44% to 53% across age groups. (table 1). Conclusion: The dimensions of the LC ossification center are large enough to allow interference screw fixation in children 3 to 6 years of age.

Auto-segmentation of important centers of growth in the pediatric skeleton to consider during radiation therapy based on deep learning.

Routinely delineating of important skeletal growth centers is imperative to mitigate radiation-induced growth abnormalities for pediatric cancer patients treated with radiotherapy. However, it is hindered by several practical problems, including difficult identification, time consumption, and inter-practitioner variability. The goal of this study was to construct and evaluate a novel Triplet-Attention U-Net (TAU-Net)-based auto-segmentation model for important skeletal growth centers in childhood cancer radiotherapy, concentrating on the accuracy and time efficiency. A total of 107 childhood cancer patients fulfilled the eligibility criteria were enrolled in the training cohort (N=80) and test cohort (N=27). The craniofacial growth plates, shoulder growth centers, and pelvic ossification centers, with a total of 19 structures in the three groups, were manually delineated by two experienced radiation oncologists on axial, coronal, and sagittal computed tomography images. Modified from U-Net, the proposed TAU-Net has one main branch and two bypass branches, receiving semantic information of three adjacent slices to predict the target structure. With supervised deep learning, the skeletal growth centers contouring of each group was generated by three different auto-segmentation models: U-Net, V-Net, and the proposed TAU-Net. Dice similarity coefficient (DSC) and Hausdorff distance 95% (HD95) were used to evaluate the accuracy of three auto-segmentation models. The time spent on performing manual tasks and manually correcting auto-contouring generated by TAU-Net was recorded. The paired t-test was used to compare the statistical differences in delineation quality and time efficiency. Among the three groups, including craniofacial growth plates, shoulder growth centers, and pelvic ossification centers groups, TAU-Net had demonstrated highly acceptable performance (the average DSC=0.77, 0.87, and 0.83 for each group; the average HD95=2.28, 2.07, and 2.86mm for each group). In the overall evaluation of 19 regions of interest (ROIs) in the test cohort, TAU-Net had an overwhelming advantage over U-Net (63.2% ROIs in DSC and 31.6% ROIs in HD95, p=0.001-0.042) and V-Net (94.7% ROIs in DSC and 36.8% ROIs in HD95, p=0.001-0.040). With an average time of 52.2min for manual delineation, the average time saved to adjust TAU-Net-generated contours was 37.6min (p<0.001), a 72% reduction. Deep learning-based models have presented enormous potential for the auto-segmentation of important growth centers in pediatric skeleton, where the proposed TAU-Net outperformed the U-Net and V-Net in geometrical precision for the majority status.

Susceptibility-weighted imaging to evaluate normal and abnormal vertebrae in fetuses: A preliminary study.

To evaluate the performance of susceptibility-weighted imaging (SWI) in visualizing normal and abnormal fetal vertebrae in vivo and in utero. Ninety-seven women with normal fetal vertebrae and 127 women suspected fetal vertebral anomalies on ultrasound were included in our study. SWI, true fast imaging with steady state precession (TrueFISP), and half-Fourier acquisition single-shot turbo spin-echo (HASTE) of the fetal spine were performed on 1.5-T magnetic resonance imaging. The image quality and diagnostic performance between HASTE/TrueFISP and SWI were compared. Pearson correlations to correlate the L1 centrum ossification center (COC) measurements with gestational age (GA) were performed. The visibility of the fetal vertebral structures on the SWI images (3.58±0.69) was significantly greater than those on the HASTE (1.98±0.51, p<0.001) and TrueFISP (2.63±0.52, p<0.001). The diagnostic accuracy of SWI (89.0%) was superior to HASTE/TrueFISP (48.0%) (p<0.001) and the area under the curve for SWI was 0.909 (p<0.001). The height, transverse, sagittal diameter, and area of L1 COC were linearly correlated with GA (all p<0.001). SWI proved to be a reliable method for depicting fetal vertebral structure and growth, which can significantly improve the diagnostic performance of vertebral anomalies in fetuses.

Analysis of fusion of sphenooccipital synchondrosis using computed tomography in Turkish population

ABSTRACT Ossification centres in the adult skeleton are important markers for age estimation. Sphenooccipital synchondrosis (SOS) is of particular significance in forensic anthropology case work due to its late closure in adolescent age groups. The aim of this study is to evaluate the SOS fusion degree for age estimation of the Turkish population. In this study, images of 298 patients within the age of 5 to 25 years were retrospectively examined. The fusion degree of the SOS was assessed using a 5-stage system. Eight morphological measurements were taken from sagittal images and completely open types. We found that the upper end width of the synchondrosis was significantly lower than the lower end width of the synchondrosis. SOS fusion began at the superior border of the synchondrosis. Fusion starts 2 years earlier in females than in males, and the process of fusion completes at the age of 17 years in males and at the age of 19 years in females in this study. In conclusion, we consider that the differences in SOS fusion among studies are due to racial diversity and different methodologies and the SOS fusion stage is as a supportive evidence for age estimation in the presence of other clues.

Sonographic Identification and Measurement of the Epiphyseal Ossification Centers in the Prediction of Fetal Lung Maturity in Pregnant Egyptian Women

Sonographic Identification and Measurement of the Epiphyseal Ossification Centers in the Prediction of Fetal Lung Maturity in Pregnant Egyptian Women

Evolution of the therian face through complete loss of the premaxilla.

The anatomical framework of the jawbones is highly conserved among most of the Osteichthyes, including the tetrapods. However, our recent study suggested that the premaxilla, the rostralmost upper jaw bone, was rearranged during the evolution of therian mammals, being replaced by the septomaxilla at least in the lateral part. In the present study, to understand more about the process of evolution from the ancestral upper jaw to the therian face, we re-examined the development of the therian premaxilla (incisive bone). By comparing mouse, bat, goat, and cattle fetuses, we confirmed that the therian premaxilla has dual developmental origins, the lateral body and the palatine process. This dual development is widely conserved among the therian mammals. Cell-lineage-tracing experiments using Dlx1-CreERT2 mice revealed that the palatine process arises in the ventral part of the premandibular domain, where the nasopalatine nerve distributes, whereas the lateral body develops from the maxillary prominence in the domain of the maxillary nerve. Through comparative analysis using various tetrapods, we concluded that the palatine process should not be considered part of the ancestral premaxilla. It rather corresponds to the anterior region of the vomerine bone of nonmammalian tetrapods. Thus, the present findings indicate that the true premaxilla was completely lost during the evolution of the therian mammals, resulting in the establishment of the unique therian face as an evolutionary novelty. Reconsideration of the homological framework of the cranial skeleton based on the topographical relationships of the ossification center during embryonic development is warranted.

Fetal magnetic resonance imaging of lumbar spine development in vivo: a retrospective study

ObjectiveThe aim of this study is to describe MR imaging appearances of the fetal lumbar spine in vivo at different gestational ages (GAs).MethodsThis retrospective study was approved by the Third Affiliated Hospital of Zhengzhou University. We collected MR images and clinical data of 93 fetuses in our hospital. All the MR images were obtained by 3-T MR. All had the mid-sagittal plane of steady state free precession sequence (Trufi) of the lumbar spine, which could show the lumbar vertebra and conus medullaris (CM). Regression analysis was made between GA and heights of lumbar vertebral body ossification center (LVBOC), lengths of LVBOC, and heights of intervertebral gap (IVG).ResultsThere were good linear correlations between the heights of LVBOC and GA (P < 0.001), lengths of LVBOC and GA (P < 0.001), and heights of IVG and GA (P < 0.001).ConclusionWe showed the different development of each LVBOC and IVG which caused the difference of the shape of LVBOC and IVG.

Developmental osteology of Ictalurus punctatus and Noturus gyrinus (Siluriformes: Ictaluridae) with a discussion of siluriform bone homologies

Abstract The skeleton of Siluriformes is characterized by several autapomorphies, including secondary absence, extreme modification, and purported fusion of several ossifications. Although well documented in adults, information on skeletal development in catfishes is relatively sparse and typically focused on particular regions of the skeleton (e.g., Weberian apparatus). To further our understanding of the siluriform skeleton, I document the development of the entire skeleton in two ictalurid species, Ictalurus punctatus (channel catfish) and Noturus gyrinus (tadpole madtom) from five days pre-hatch to adult. I reexamine the homologies of bones previously hypothesized to represent compound elements in catfishes as well as an additional element only known to occur in some ictalurids. Development of the skeleton is complete in I. punctatus at 22.4 mm SL and almost complete in N. gyrinus (except dorsal- and anal-fin distal radials) at 14.1 mm SL. No signs of ontogenetic fusion were observed in any of the purported compound elements. Previous hypotheses of the homology of these elements and of additional ossifications are reviewed in light of developmental information obtained herein. No dermal parietal component is present at any stage in the so-called parieto-supraoccipital. The bone is the supraoccipital which ossifies from two lateral centers of ossification which later fuse, rather than from a median center. The ‘posttemporo-supracleithrum’ originates from a single center of ossification and represents the supracleithrum. The posttemporal is present in ictalurids and many other catfishes as a canal-bearing bone between the supracleithrum and the pterotic, a bone sometimes identified as the extrascapular. The extrascapular is missing in catfishes. Ictalurids have an additional dermal bone above the posttemporal, which is either an independently ossifying fragment of the posttemporal or a neoformation restricted to some members of this family. The single chondral bone of the pectoral girdle originates from a single center of ossification that represents the coracoid. The scapula is missing in catfishes. Dorsal-fin distal radial 2 is absent in catfishes and the foramen of dorsal-fin spine 2 is formed from modifications to the base of the fin-ray itself. Unlike loricarioid catfishes, the urohyal of ictalurids originates solely as an ossification of the sternohyoideus tendons. The anteriormost infraorbital element ossifies from a single center of ossification around the infraorbital sensory canal and represents the lacrimal. The antorbital is missing in catfishes. Finally, skeletal development of I. punctatus is compared to that available for other otophysans, including the cypriniforms Danio rerio and Enteromius holotaenia and the characiform Salminus brasiliensis.

Characteristics of the length of the radius and ulna in children.

ObjectivesCongenital malformation, trauma, tumor, or metabolic disease can cause length deformity of the radius or ulna, affecting the appearance and function of the forearm. Osteotomy and lengthening with external fixation can obviously improve the length of the radius and ulna (LRU). However, the extent of lengthening required is still unclear. This study analyzed the LRU in children, to provide suggested standards for various orthopedic treatments.MethodsNormal LRUs were measured on X-ray images in children who came to hospital for emergency treatment, with measurements including anterior–posterior (AP) radiographs, lateral (LAT) radiographs, full LRU (total length), and LRU without the epiphysis (short length). Any cases of fracture or deformity affecting measurement were excluded. Three hundred twenty-six cases were divided into 16 groups according to age from 1 year old to 16 years old.ResultsThe earliest epiphyseal plate and ossification center were observed in the distal part of the radius at 1 year old, and in the proximal part at 3 years old in both boys and girls. In the ulna, at the distal end it was 6 years old in girls and 7 years old in boys, while in the proximal part ossification was observed at 9 years old in both boys and girls. The proximal epiphyseal plate of the ulna began to close on X-ray images at 12 years old in girls and 13 years in boys. LRU increased with age, and there was a strong positive correlation and consistent ratio between radius, ulna and age. In short length, the ratio of the length of radius to ulna (RLRU) ranged from 0.8941 to 0.9251 AP, from 0.8936 to 0.9375 LAT. In total length, RLRU ranged from 0.9286 to 0.9508 AP, and 0.9579 to 0.9698 LAT.ConclusionsThe length and epiphyseal ossification of the radius and ulna are associated with age. RLRU is also limited to a certain range and tends to remain stable with age. These characteristics have clinical significance for deformity correction of the forearm.

Cranial Base Synchondrosis Lacks PTHrP-Expressing Column-Forming Chondrocytes.

The cranial base contains a special type of growth plate termed the synchondrosis, which functions as the growth center of the skull. The synchondrosis is composed of bidirectional opposite-facing layers of resting, proliferating, and hypertrophic chondrocytes, and lacks the secondary ossification center. In long bones, the resting zone of the epiphyseal growth plate houses a population of parathyroid hormone-related protein (PTHrP)-expressing chondrocytes that contribute to the formation of columnar chondrocytes. Whether PTHrP+ chondrocytes in the synchondrosis possess similar functions remains undefined. Using Pthrp-mCherry knock-in mice, we found that PTHrP+ chondrocytes predominantly occupied the lateral wedge-shaped area of the synchondrosis, unlike those in the femoral growth plate that reside in the resting zone within the epiphysis. In vivo cell-lineage analyses using a tamoxifen-inducible Pthrp-creER line revealed that PTHrP+ chondrocytes failed to establish columnar chondrocytes in the synchondrosis. Therefore, PTHrP+ chondrocytes in the synchondrosis do not possess column-forming capabilities, unlike those in the resting zone of the long bone growth plate. These findings support the importance of the secondary ossification center within the long bone epiphysis in establishing the stem cell niche for PTHrP+ chondrocytes, the absence of which may explain the lack of column-forming capabilities of PTHrP+ chondrocytes in the cranial base synchondrosis.

Bilateral osteochondroses of the accessory ossification centre of the medial malleolus: A rare entity

We are reporting a rare case of a painful accessory ossification center of the bilateral medial malleoli in a 9 years old girl. Patient was not involved in any sport activity. There was no local foot deformity and limb malalignment. The patient was treated conservatively. There was complete clinical and radiographic healing of the medial malleolus eight months after the first presentation. Osteochondrosis of the accessory ossification center of medial malleolus is generally unilateral and bilateral involvement is very rare. There are various differential diagnosis for this pathological condition with similar clinical features and presentation in this age group. We ruled out the uncommon pathological conditions causing chronic pain in the medial malleolus during this period of skeletal growth. We consider this painful condition to be classified as a bilateral osteochondroses of the accessory ossification center of the medial malleolus. Osteochondrosis of the accessory ossification center of the bilateral medial malleolus is a rare entity. Due to rarity of disease and common presentation similar to other disease this is commonly misdiagnosed or missed in clinical practice. Osteochondrosis is characterized by a disturbance of endochondral ossification in skeletally immature patients and should be investigated in children having a history of persistent foot and ankle pain. An increased clinical attention to this painful condition could lead to improved diagnosis and treatment among the paediatric age group.

Biomechanical Assessment of Fracture Loads and Patterns of the Odontoid Process.

Laboratory study. This study aimed to investigate the biomechanical competence and fracture characteristics of the odontoid process. Odontoid fractures of the second cervical vertebra (C2) represent the most common spine fracture type in the elderly. However, very little is known about the underlying biomechanical fracture mechanisms. A total of 42 C2 human anatomic specimens were scanned via computed tomography, divided in six groups, and subjected to combined quasistatic loading at -15°, 0°, and 15° in sagittal plane and -50° and 0° in transverse plane until fracturing. Bone mineral density (BMD), height, fusion state of the ossification centers, stiffness, yield load, and ultimate load were assessed. While lowest values for stiffness, yield load, and ultimate load were observed at load inclination of 15° in sagittal plane, no statistically significant differences were observed between the study groups ( P ≥0.235). BMD correlated positively with yield load ( r2 =0.350, P <0.001) and ultimate load ( r2 =0.955, P <0.001) but not with stiffness ( r2 =0.082, P =0.07). The specimens with clearly distinguishable fusion of the ossification centers revealed less data scattering of the biomechanical outcomes. Load direction plays a subordinate role in traumatic fractures of the odontoid process. BMD was associated with significant correlation to the biomechanical outcomes. Thus, odontoid fractures appear to result from of an interaction between the load magnitude and bone quality.

“Superior Pectus Carinatum” (Currarino–Silverman Syndrome) in a 66-year-old woman: a case report

The premature fusion of some of the sternal ossification centers and the obliteration of the manubrio-sternal joint caused a rare deformity called CurrarinoSilverman syndrome. Patients present an abnormally short sternum with a forward angulation at the manubrio-sternal junction. Cardiopulmonary diseases and spinal deformities are the most frequent related disorders. It was also described as a component of Turners and Noonans syndromes.&#x0D; Herein, we present the case of a 66-year-old woman who presented to our clinic for follow-up computed tomography after surgery and chemotherapy for breast cancer with frequent episodes of dyspnea, wheezing, bronchitis, and mild dyspnea annually, which was more frequent during childhood. Computed tomography showed the absence of metastatic lesions and other accompanying diseases, except for a rare deformity of the anterior chest wall, the so-called, a superior pectus carinatum, a chondromanubrial deformity with a dorsal-open angle of 130, and a sternum body length of 9 cm, which is not depressed in the lower third.