Cranial Bone Research Articles

HtrA3 paves the way for MSC migration and promotes osteogenesis

Mesenchymal stem cell (MSC) migration determines the healing capacity of bone and is crucial in promoting bone regeneration. Migration of MSCs is highly dependent on degradation of extracellular matrix by proteolytic enzymes. However, the underlying mechanisms of how enzymolysis paves the way for MSCs to migrate from their niche to the defect area is still not fully understood. Here, this study shows that high-temperature requirement A3 (HtrA3) overcomes the physical barrier and provides anchor points through collagen IV degradation, paving the way for MSC migration. HtrA3 is upregulated in MSCs at the leading edge of bone defect during the early stage of healing. HtrA3 degrades the surrounding collagen IV, which increases the collagen network porosity and increases integrin β1 expression. Subsequently, integrin β1 enhances the mechanotransduction of MSCs, thus remodeling the cytoskeleton, increasing cellular stiffness and nuclear translocation of YAP, eventually promoting the migration and subsequent osteogenic differentiation of MSCs. Local administration of recombinant HtrA3 in rat cranial bone defects significantly increases new bone formation and further validates the enhancement of MSC migration. This study helps to reveal the novel roles of HtrA3, explore potential targets for regenerative medicine, and offer new insights for the development of bioactive materials.

Tranexamic acid loaded in a physically crosslinked trilaminate dressing for local hemorrhage control: Preparation, characterization, and in-vivo assessment using two different animal models

This work aimed at formulating a trilaminate dressing loaded with tranexamic acid. It consisted of a layer of 3 % sodium hyaluronate to initiate hemostasis. It was followed by a mixed porous layer of 5 % polyvinyl alcohol and 2 % kappa–carrageenan. This layer acted as a drug reservoir that controlled its release. The third layer was 5 % ethyl cellulose backing layer for unidirectional release of tranexamic acid towards the wound. The 3 layers were physically crosslinked by hydrogen bonding as confirmed by Infrared spectroscopy. Swelling and release studies were performed, and results proposed that increasing number of layers decreased swelling properties and sustained release of tranexamic acid for 8 h. In vitro blood coagulation study was performed using human blood and showed that the dressing significantly decreased coagulation time by 70.5 % compared to the negative control. In vivo hemostatic activity was evaluated using tail amputation model in Wistar rats. Statistical analysis showed the dressing could stop bleeding in a punctured artery of the rat tail faster than the negative control by 59 %. Cranial bone defect model in New Zealand rabbits was performed to check for bone hemostasis and showed significant decrease in the hemostatic time by 80 % compared to the control.

A Composite Hydrogel Functionalized by Borosilicate Bioactive Glasses and VEGF for Critical-Size Bone Regeneration.

Critical-size bone defects pose a formidable challenge in clinical treatment, prompting extensive research efforts to address this problem. In this study, an inorganic-organic multifunctional composite hydrogel denoted as PLG-g-TA/VEGF/Sr-BGNPs is developed, engineered for the synergistic management of bone defects. The composite hydrogel demonstrated the capacity for mineralization, hydroxyapatite formation, and gradual release of essential functional ions and vascular endothelial growth factor (VEGF) and also maintained an alkaline microenvironment. The composite hydrogel promoted the proliferation and osteogenic differentiation of rat bone marrow mesenchymal stem cells (rBMSCs), as indicated by increased expression of osteogenesis-related genes and proteins in vitro. Moreover, the composite hydrogel significantly enhanced the tube-forming capability of human umbilical vein endothelial cells (HUVECs) and effectively inhibited the process of osteoblastic differentiation of nuclear factor kappa-B ligand (RANKL)-induced Raw264.7 cells and osteoclast bone resorption. After the implantation of the composite hydrogel into rat cranial bone defects, the expression of osteogenic and angiogenic biomarkers increased, substantiating its efficacy in promoting bone defect repair in vivo. The commendable attributes of the multifunctional composite hydrogel underscore its pivotal role in expediting hydrogel-associated bone growth and repairing critical bone defects, positioning it as a promising adjuvant therapy candidate for large-segment bone defects.

Key Roles of Gli1 and Ihh Signaling in Craniofacial Development.

The Hedgehog (Hh) signaling pathway orchestrates its influence through a dynamic interplay of Hh proteins, the cell surface receptor Ptch1, Smo, and Gli transcription factors, contributing to a myriad of developmental events. Indian Hedgehog (Ihh) and Gli zinc finger transcription factor 1 (Gli1) play crucial roles in developmental regulation within the Hh signaling pathway. Ihh regulates chondrocyte proliferation, differentiation, and bone formation, impacting the development of cranial bones, cartilage, and the temporomandibular joint (TMJ). Losing Ihh results in cranial bone malformation and decreased ossification and affects the formation of cranial base cartilage unions, TMJ condyles, and joint discs. Gli1 is predominantly expressed during early craniofacial development, and Gli1+ cells are identified as the primary mesenchymal stem cells (MSCs) for craniofacial bones, crucial for cell differentiation and morphogenesis. In addition, a complex mutual regulatory mechanism exists between Gli1 and Ihh, ensuring the normal function of the Hh signaling pathway by directly or indirectly regulating each other's expression levels. And the interaction between Ihh and Gli1 significantly impacts the normal development of craniofacial tissues. This review summarizes the pivotal roles of Gli1 and Ihh in the intricate landscape of mammalian craniofacial development and outlines the molecular regulatory mechanisms and intricate interactions governing the growth of bone and cartilage exhibited by Gli1 and Ihh, which provides new insights into potential therapeutic strategies for related diseases or researches of tissue regeneration.

Construction of a Lentiviral Vector for Fgfr2 Overexpression and its Impact on the Biological Behavior of Cranial Suture Mesenchymal Stem Cells.

Suture mesenchymal stem cells (SuSCs), possessing self-renewal and multilineage differentiation abilities, play a crucial role in cranial bone growth. However, the impact of the disease-causing fibroblast growth factor receptor 2 (FGFR2) mutation on SuSCs in Crouzon syndrome has not been explored. This study aims to employ a lentivirus to overexpress Fgfr2 and investigate its role in the pathogenesis of Crouzon syndrome. Starting with the prevalent FGFR2 mutation site in patients with Crouzon syndrome, a lentiviral vector carrying the Fgfr2.C361Y mutation was developed and transfected into SuSCs, with a determined multiplicity of infection values. The experimental group, SuSCs+Fgfr2.C361Y, was compared with the empty vector and normal SuSC groups. Cell proliferation, cycle, apoptosis, and osteogenic functionality were assessed using CCK-8 assays, flow cytometry, ALP activity assays, and real-time quantitative polymerase chain reaction. The lentiviral vector effectively infected SuSCs, leading to heightened Fgfr2 expression, with optimal multiplicity of infection values of 80. The experimental group demonstrated decreased proliferation activity and a higher apoptosis rate compared with controls (P < 0.05). After osteogenic induction, the experimental group showed significantly higher ALP activity than controls (P < 0.05). Real-time quantitative polymerase chain reaction indicated lower mRNA expression levels of Gli1, Axin2, Pcna, Cdk2, and Bcl-2 in the experimental group than controls, whereas Bax, Runx2, and Bmp-2 showed higher expression (P < 0.05). This study constructed a lentivirus vector to upregulate Fgfr2 expression in SuSCs, suppressing stem cell stemness by inhibiting proliferation, promoting apoptosis, and accelerating premature osteogenic differentiation, resulting in premature suture closure. These findings establish the groundwork for further understanding the pathogenesis of Crouzon syndrome.

Evaluation and 3D imaging of mineral structure changes of the rabbit (New Zealand) skull during developmental periods.

This study aimed to determine the morphometric measurements anatomically and CT images of skulls of healthy male and female rabbits during postnatal development, to analyse the data statistically and to demonstrate the structural changes in bone. A total of 40 rabbits (20 females and 20 males) were divided into four groups including prepubertal period (group I (0-1 month)), period between adolescence and adulthood (group II (3-5 month)) and later (young adult period as group III (1-3 years) and old adult period as group IV (3-5 years)), with five animals in each group. After the morphometric measurements, the surface area and volume values of the skull were calculated. The skulls were reconstructed using a 3D Slicer (5.0.2), which is used for 3D modelling. The cranial bones in each group were then crushed using a grinder so that the powdered samples were obtained for XRF (X-ray fluorescence technique). The p-value was statistically highly significant between group and gender (p < 0.001). In morphometric measurements, males were generally higher than females. Only PL, GBOC and GNB measurements were higher in females. The p-value between groups (in all measurements), between genders (in TL, GLN, FL, VL, OZB and GBN parameters) and between groups and genders (in TL, DL and VL parameters) was statistically highly significant (p < 0.001). The p-value between the groups, p-value between sexes and p-value between group and sex in Si, P, K, Ca, Ni, Zn, Sr, Sr and Ca/P elements were statistically significant (p < 0.001). Consequently, metric, volume and surface area measurements were taken through 3D modelling of skull bone in prepubertal period (group I), period between adolescence and adulthood (group II) and later (young adult period as group III and old adult period as group IV) of rabbits and the change in the mineral structure during postnatal development and effect of sex on this change were investigated. This might be the first study to assess both metric and mineral changes at four age intervals taken during the life span of rabbits.

Discovery of the choristodere Hyphalosaurus baitaigouensis from the Lower Cretaceous Jiufotang Formation of western Liaoning, China and its paleobiogeographic significance

The water-living reptile genus Hyphalosaurus was previously discovered in the Lower Cretaceous Yixian Formation bearing the middle Jehol Biota in western Liaoning, China. Two complete skeletons of Hyphalosaurus are reported for the first time from the Jiufotang Formation bearing the late Jehol Biota at two sites in western Liaoning. They show the typical characteristics of Hyphalosaurus baitaigouensis in terms of the contact between some cranial bones and the number of cervical and dorsal vertebrae, and therefore are assigned to H. baitaigouensis. This discovery extends the stratigraphic range of this species from the Yixian Formation to the overlying Jiufotang Formation. This paper further briefly compares the main characteristics of the two skeletons, summarizes the temporal and spatial distribution of Hyphalosaurus, and discusses the palaeogeographic evolution of western Liaoning at the middle and late Jehol Biota stages based on the aquatic habits of Hyphalosaurus and the geological background of western Liaoning. The analytical results show that the volcanic downwarped lakes, with distinct geographical divisions in western Liaoning during the deposition of the Yixian Formation, had not completely disappeared till the deposition of the Jiufotang Formation. The palaeo-lake in the Fuxin-Yixian Basin underwent the process of generation, expansion and shrinkage during the depositional period of the Yixian Formation and finally merged into a large lake. The palaeo-Dalinghe River, which connected the main basins in western Liaoning during the depositional period of the Jiufotang Formation, was formed simultaneously.

Transcranial direct current stimulation alters cerebrospinal fluid-interstitial fluid exchange in mouse brain

BackgroundTranscranial direct current stimulation (tDCS) is a non-invasive brain stimulation technique that has gained prominence recently. Clinical studies have explored tDCS as an adjunct to neurologic disease rehabilitation, with evidence suggesting its potential in modulating brain clearance mechanisms. The glymphatic system, a proposed brain waste clearance system, posits that cerebrospinal fluid-interstitial fluid (CSF-ISF) exchange aids in efficient metabolic waste removal. While some studies have linked tDCS to astrocytic inositol trisphosphate (IP3)/Ca2+ signaling, the impact of tDCS on CSF-ISF exchange dynamics remains unclear. HypothesistDCS influences the dynamics of CSF-ISF exchange through astrocytic IP3/Ca2+ signaling. MethodsIn this study, we administered tDCS (0.1 mA for 10 min) to C57BL/6N mice anesthetized with ketamine-xylazine (KX). The anode was positioned on the cranial bone above the cortex, and the cathode was inserted into the neck. Following tDCS, we directly assessed brain fluid dynamics by injecting biotinylated dextran amine (BDA) as a CSF tracer into the cisterna magna (CM). The brain was then extracted after either 30 or 60 min and fixed. After 24 h, the sectioned brain slices were stained with Alexa 594-conjugated streptavidin (SA) to visualize BDA using immunohistochemistry. We conducted Electroencephalography (EEG) recordings and aquaporin 4 (AQP4)/CD31 immunostaining to investigate the underlying mechanisms of tDCS. Additionally, we monitored the efflux of Evans blue, injected into the cisterna magna, using cervical lymph node imaging. Some experiments were subsequently repeated with inositol trisphosphate receptor type 2 (IP3R2) knockout (KO) mice. ResultsPost-tDCS, we observed an increased CSF tracer influx, indicating a modulation of CSF-ISF exchange by tDCS. Additionally, tDCS appeared to enhance the brain's metabolic waste efflux. EEG recordings showed an increase in delta wave post-tDCS. But no significant change in AQP4 expression was detected 30 min post-tDCS. Besides, we found no alteration in CSF-ISF exchange and delta wave activity in IP3R2 KO mice after tDCS. ConclusionOur findings suggest that tDCS augments the glymphatic system's influx and efflux. Through astrocytic IP3/Ca2+ signaling, tDCS was found to modify the delta wave, which correlates positively with brain clearance. This study underscores the potential of tDCS in modulating brain metabolic waste clearance.

Retrospective analysis of pattern of injuries and cause of death in unclaimed dead bodies brought to Mortuary of Private Medical Institute

Introduction: Establishment of identity is required both in living and dead bodies and in both civil and criminal cases. Unclaimed body is defined as dead person who had no next of kin or no relative or no authorized representative willing to make final disposition of the remains.Aims and objective: The aim of this study was to determine the pattern and distribution of injuries and to find out the cause of the death in unclaimed bodies.Material and methods: In this retrospective study all the autopsies of unclaimed body from September 2018 to August 2022 were included.Results: A total 75 unclaimed body were brought to mortuary for autopsy. Out of 75 cases, 65 (87%) were male and 10 (13 %) were female. Majority of unclaimed bodies in this study belonged to age group 40-50. Contusion on the body was most common type of external injury. Lower limb was most common body part for external injuries. Skull was most common site for fracture. Temporal and temporoparietal were most common cranial bone fractured. Mandible was most common facial bone fractured. Liver laceration was most common internal organ injured in unclaimed bodies. Subarachnoid haemorrhage was most common intracranial haemorrhage. Most common cause of death in the present study was haemorrhage and shock due to antemortem injury.Conclusions: Identification of unclaimed dead body need to be increased by police workforce. Bodies which are unclaimed should be brought to mortuary just after prompt investigation so that autopsy should be started before decomposition which may interfere with autopsy finding and even in identification of the unclaimed body. Colour photography, DNA sampling, finger printing and maintaining dental records should be done for every unclaimedbody.

Does cranial bone ossification differ in children with developmental dysplasia of the hip?

This study aims to compare cranial bone ossification between patients with developmental dysplasia of the hip (DDH) and healthy individuals. Between September 2021 and April 2022, a total of 60 healthy female individuals (median age: 24.5 months; range, 18 to 36 months) and 56 female DDH patients (median age: 23 months; range, 18 to 35 months) were included. Age, head circumference, weight, height, and patency of the anterior fontanel were measured in groups. Percentiles were classified as very low, low, normal, high and very high. All patients were female and those with abnormal thyroid function test, vitamin D, calcium, phosphate and alkaline phosphatase values were not included in the study. For those diagnosed with DDH, they were included in the group regardless of the type of treatment. No statistically significant difference was found between the groups in terms of age and weight (p>0.05). The very low and very high head circumferences were more frequent, and the normal head circumferences were less frequent in the DDH group (p<0.05). There was no significant difference between groups in terms of fontanel closure (p>0.05). In open fontanels, no significant difference was found in both groups in terms of age (p>0.05). Our study results showed no significant difference between the fontanel ossifications of children with and without DDH; however, we found that the ossification of the skull bones of children with DDH was different compared to healthy children.

Wnt signaling in cranial bones as a proponent of TH-induced craniosynostosis.

Craniosynostosis (CS) is the premature fusion of the sutures within the skull during embryonic development. Recently, thyrotoxicosis in pregnant women has been shown to increase the risk of craniosynostosis in the developing fetus, but the specific mechanism relating the accelerated bone development in CS to increased thyroid hormone (TH) is unknown. Different cell signaling pathways, such as Wnt, Ihh, BMP, and IGF-1, have been identified in TH regulated bone development. However, the Wnt pathway has been chosen in this study for its extensive involvement in bone development. It is known that Wnt-signaling increases levels of β-catenin which then drives the transcription of Wnt/β-catenin target genes such as Twist1 and Runx2. When upregulated, these genes have been linked to increased osteoblast differentiation and bone formation. In this study, we aimed to determine the level of Wnt signaling activation, in cranial bones of differing embryonic origins (frontal and parietal bones) from an avian model of thyrotoxicosis. Collected bones were processed for assessing β-catenin protein expression by western blotting and Twist1 and Runx2 gene expression by qRT-PCR. Analysis is currently in progress. We predict that differences will be observed between the parietal and frontal bones as the parietal bones derive from the mesoderm whereas the frontal bones derive from the neural crest.

The existence of cranial bone flap displacement during brain radiotherapy

SummaryThis retrospective study examined bone flap displacement during radiotherapy in 25 post-operative brain tumour patients. Though never exceeding 2.5 mm, the sheer frequency of displacement highlights the need for future research on larger populations to validate its presence and assess the potential clinical impact on planning tumour volume margins.

Suture-like pattern formation in the pterygospinous bridge of the human sphenoid bone.

The paper presents an anatomical study involving rare variations in the pterygospinous bridges found in Mongolian skulls. These structures extend between the lateral pterygoid plate and the sphenoid spine. Particularly interesting is the division of these bridges into two distinct parts of the similar length. The junctions within these structures resemble morphological patterns characteristic for the plain and zigzag sutures, which articulate the cranial bones.

Biomechanics as support for forensic expert reports in after pedestrian-car collisions

This paper systematically explores the mechanical properties of facial and cranial bones, aiming to contribute to the understanding of brain and cervical spine injuries from a mechanical/biomechanical perspective. The research also seeks to provide insights applicable in forensic practice, bridging the gap for engineering professionals not typi-cally involved in forensic medicine. Strength and stiffness parameters of facial and cra-nial bones were utilized to analyze forces leading to fractures, proposing a simple analyt-ical approach for determining head velocity upon striking a car windshield. Experimental testing was conducted to examine defects on the windshield resulting from an impactor's crash, simulating head impacts at varying velocities. Two approaches for determining head impact velocity during pedestrian-car collisions were explored. The first, neglect-ing body deformation effects, assumes that the manikin's center of gravity moves at the same speed as the impacting vehicle, resulting in an impact velocity that is approximate-ly twice the car's speed. The second, a more realistic scenario, considers slower move-ment of the body's center of gravity, yielding an impact velocity that is about one and a half times the car's speed, with a specific angle relative to the X-axis. Calculation reveals that head impact velocity decreases with reduced windshield inclination at constant ve-hicle speed. Experimental testing with an adult head impactor monitored impact velocity, acceleration, contact time, and puncture diameter and depth on the vehicle glass. Results align closely with published data, emphasizing higher injury risk near the location of fixation of the windshield to the frame of the vehicle. In forensic investigations, the re-search findings, including newly measured or calculated parameters, offer practical ap-plications. Acknowledging simulation limitations, the study emphasizes the reliance on experimental data for a more realistic understanding. Application of knowledge in expert opinions for car crashes with injuries involves considering windshield defect dimen-sions in relation to speed, minimizing the need for revision by expert opinions. This comprehensive exploration contributes to understanding biomechanical factors influenc-ing injuries, particularly in vehicular accidents, and underscores the importance of em-pirical data in forensic practice. The proposed analytical approach and experimental insights provide valuable tools for forensic professionals and contribute to the broader understanding of injury mechanisms.

Paleoanthropological Analysis of Osteological Material from the Myntobe Burial Ground

The article deals with the paleoanthropological analysis of the skeletons unearthed from the Myntobe necropolis and dated to the II – IV centuries AD. Myntobe necropolis is located 2 km south of Gani Muratbayev village in the Keles district of Turkestan province. The burial ground consists of more than 600 randomly located mounds of various sizes. All mounds have a dirt embankment. Archaeological excavations were carried out at the burial ground in 2017 and 2022, as a result of which burials in the catacombs and naus were unearthed. An analysis of the burial tradition and recovered material allows researchers to speak about the belonging of these burials to the Kangli tribes. Since the burials date back to the Kangli period, the theoretical part reveals the issues of the location and political structure of the tribes and, most importantly, the determination of the paleopathology of the Myntobints by conducting a macroscopic analysis of the discovered skeletons. The results of the analysis allowed for drawing preliminary conclusions about lifestyle, social life, and nutritional status. When writing the theoretical part of the article, electronic textbooks and resources from the book fund of the National Library of Kazakhstan and the library of the International Kazakh-Turkish University named after Kozh Ahmet Yasawi were used. In total, 9 skeletons were selected for paleoanthropological and paleopathological analysis, from mounds No. 3, No. 6, and No. 7. Paleoanthropological reasoning in the main section is written on the basis of materials in Turkish and English from the collections of Turkish libraries. The skeletons found were analyzed macroscopically and many diseases were identified, such as osteoarthritis (joint deformity), osteopathy, ankylosing spondylitis, heel spurs, thickening of the cranial bone, and deformity of the mandibular joint. Preliminary conclusions about the paleopathology of the discovered skeletons are made.

Surgical Reconstruction of a Large Defect after Excision of Infiltrative Squamous Cell Carcinoma in the Scalp and Occipital Region: A Case Report

Squamous cell carcinoma (SCC) of the scalp is the second most prevalent skin cancer, following basal cell carcinoma. Notably, it has the capability to infiltrate the skull, dura mater, and even brain tissue. The cornerstone of treatment is the surgical removal of the lesion, with a particular focus on the depth of invasion, which is directly correlated with recurrence rates. Post-surgical strategies may involve immediate or delayed cranial bone reconstruction and repair of scalp defects using either artificial dermis or skin grafts. In the case presented, a substantial defect necessitated more than a single flap for primary repair. Hence, a single pedicle double-island flap was designed for reconstructing the occipital area. Due to increased tension on the flap following cranial bone repair, the bone repair was temporarily deferred. Postoperative care included adjuvant chemotherapy and radiotherapy to mitigate the risk of SCC recurrence.

Infantile Myofibroma of the Frontal Bone: A Case Report

Background: Infantile myofibroma stands as the most prevalent fibrous neoplasm within the pediatric population, despite its rarity. The majority of these tumors manifest within the initial 2 years of life. Clinically, myofibroma lesions are classified into solitary and multicentric tumors. Methods: We present a case of infantile myofibroma located within the frontal bone of a 16-month-old infant. Initial evaluation of the swelling and its spread was conducted using CT and MRI scans. Subsequently, the diagnosis was confirmed through a core needle biopsy. Results: The tumor underwent surgical excision with 1 cm safety margin and immediate reconstruction with strips of calvaria bone graft. Histopathology of the specimen showed complete tumor clearance with actual margin of 7 mm. Conclusion: The surgical resection of cranial benign bone tumors should be meticulously planned with a multidisciplinary approach. Wherever possible, immediate reconstruction should be conducted to avoid the morbidity of a subsequent procedure.

The relationship between anterior fontanelle and head circumference in term newborns

Aims: At birth, infants have membranous cavities called fontanelles because the angles of the skull bones have not yet formed. Its size is generally accepted as an indicator of cranial development and bone maturation. Head circumference measurement is an important marker for predicting brain development, especially in early childhood. Methods: Patients followed up in the pediatric outpatient clinic of Kırşehir Training and Research Hospital between January 2020 and January 2024 were retrospectively analyzed. Anterior fontanelle width and head circumference measurements of babies born on the day recorded in the system were recorded. Results: A total of 340 (M/F: 188/152) patients were included in the study. There was a positive correlation between fontanel width and head circumference at birth, at 1 month and at 2 months (p&lt;0.05). There was no correlation between fontanel width and head circumference at 3,4,6, 9, 12 months (p&gt;0.05). Conclusion: A significant relationship was found between anterior fontanelle width and head circumference in the first months of life. It is considered to be taken into consideration in the follow-up of healthy children. However, further studies are needed in this context and our study will contribute to future studies.

Bone flap binding and transposition: a method for bone reconstruction in cranial burst fractures and early-stage growing skull fractures.

To introduce a method of cranial bone reconstruction for cranial burst fractures and early-stage growing skull fractures, named bone flap binding and transposition. Cranial burst fractures, severe head injuries predominantly observed in infants, are characterized by widely diastatic skull fractures coupled with acute extracranial cerebral herniation beneath an intact scalp through ruptured dura mater. These injuries can develop into growing skull fractures. This study included two cases to illustrate the procedure, with a particular focus on the bone steps in managing these conditions. The medical history, clinical presentation, surgical procedures, and postoperative follow-up were retrospectively studied. The details of the surgical procedure were described. The method of bone reconstruction, named bone flap binding and transposition, was applied after the lacerated dural repair. Two bone pieces were combined to eliminate the diastatic bone defect and then fixed by an absorbable cranial fixation clip and bound by sutures. The combined bone flap was repositioned into the bone window, completely covering the area of the original dural laceration. Subsequently, the bone defect was transferred to the area of normal dura. The postoperative courses for the two infants were uneventful. Follow-up CT scans revealed new bone formation at the previous bone defect and no progressive growing skull fracture. The major cranial defects had disappeared, leaving only small residual defects at the corners of the skull bone window, which required further recovery and did not affect the solidity of the skull. Bone flap binding and transposition provide a straightforward, cost-effective, and reliable method for cranial bone reconstruction of cranial burst fractures and early-stage growing skull fractures. This method has taken full advantage of the small infant's dura osteogenic potential without the need for artificial or metallic bone repair materials. The effectiveness of the method needs further validation with more cases in the future.

The efficacy of using the allogeneic osteoplastic material in skull trepanation

Introduction. When performing osteoplastic craniotomy, there is a need to fill the diastasis between the skull bone and the explanted bone fragment. Grafts based on allogeneic bone chips and collagen (bone-plastic material) may be very effective for cranial bone repair in diastasis area.Aim. To evaluate the safety and clinical efficacy of osteoplastic material during the osteoplastic craniotomy.Material and methods. A retrospective and prospective clinical study was conducted at the N.V. Sklifosovsky Research Institute for Emergency Medicine and included 12 patients treated in Urgent Neurosurgery Department with diagnoses suggesting the need for craniotomy. Allogenic osteoplastic material was obtained from a 0.7-0.9% solution of type I collagen and spongy bone chips with a fraction size of 315-630 microns. Osteoplastic material grafts were used intraoperatively at the cranioplastic stage of the operation after the main stages had been completed. The efficacy and safety of the use of osteoplastic material were evaluated clinically and radiologically in the early postoperative period.Results. In the early postoperative period, the study patients had no pyo-septic complications, severe pain or soft tissue swelling. All patients were discharged from the hospital in satisfactory condition to be followed-up by the physician or neurologist at the out-patient facility. The computed tomography performed in the early postoperative period visualized the diastasis lines along the bone flap line in the comparison group patients (without osteoplastic material); and in the main group, the osteoplastic material was clearly visualized. At computed tomography of the skull performed after 6–9 months and after 2–18 months, the signs of bone tissue consolidation were visualized in the patients of the main group. The radiodensity of the autologous bone flap in both groups did not significantly change at any periods. In the diastasis area, the radiodensity of diastasis in the main group was significantly higher than in the comparison group. After 1-1.15 years the radiodensity values in the diastasis area increased by average of 1.95 times (p&lt;0.05) in the patients of the main group, while in the patients without osteoplastic material, this parameter did not significantly change during the entire follow-up period.Conclusions. In patients with intraoperative cranioplasty osteoplastic material grafts did not cause complications in the early and late postoperative period. Intraoperative cranioplasty performed with using osteoplastic allogeneic material caused no complications in either early or late postoperative periods. The presence of osteoplastic material contributed to the consolidation of the autologous bone flap and healthy bone.