Search Results (310)

Acellular bone matrix, with its natural extracellular matrix components, has been considered a potential alternative platform for bone grafting. Our study focused on fabricating acellular bovine bone matrix (ABBM) and evaluating its in vitro characteristics and in vivo effect on bone repair. The bovine cancellous bone was subjected to ABBM preparation, which included partial demineralization and decellularization processing. The effects of the ABBM on human bone marrow-derived stem cells (hBMSCs) were evaluated, including viability, migration, attachment, and proliferation. A rabbit bone defect model was implanted with ABBM and histologically assessed for bone healing. The acellular properties were determined by the absence of nuclear material and the accepted minimum residual DNA content. An in vitro study indicated the ABBM’s positive effect on the migration of hBMSCs. ABBM was also demonstrated to support hBMSC attachment and proliferation. In vivo testing was performed in rabbits with a cranial bone defect, which showed complete bone healing after 8 weeks of grafting with ABBM. Overall, the fabricated ABBM demonstrated in vitro and in vivo biocompatibility and effective support for bone healing in vivo, and therefore represents a potential xenogeneic biomaterial for bone tissue repair. Full article

A comparative study on hemicircular tibial plateau leveling osteotomy (hTPLO) and TPLO for correcting cranial cruciate ligament (CCL) ruptures at excessive tibial plateau angles (eTPAs) was performed with a specially fabricated hTPLO saw blade (hemicircular) and TPLO saw blade (quartercircular), respectively. Ten 3D-printed bone models with eTPAs (TPA > 40°), were resized to accommodate the respective saw blade shape for each method. Cranial closing wedge osteotomy (CCWO) combined with TPLO was also performed. Distances of segment rotation below the patellar tendon insertion (PTI) and differences between anatomical and mechanical axes after correction were measured. The TPAs of the bone models were 46.06 ± 4.40° (40.0–50.7°). Postoperative TPAs of hTPLO, TPLO, and TPLO combined with CCWO were 4.93 ± 1.025°, 4.52 ± 0.085°, and 4.17 ± 1.128°, respectively. Rotation distances from the PTI were 0.46 ± 2.153 mm, 8.67 ± 2.318 mm, and 1.13 ± 1.796 mm, respectively. hTPLO showed significantly less movement of the segment below the PTI than TPLO with or without CCWO (p < 0.01). Differences between anatomical and mechanical axes after hTPLO and TPLO with or without CCWO were 5.74 ± 2.231°, 6.43 ± 2.105°, and 5.16 ± 2.465°, respectively. Within the limitations of this model-based study, hTPLO demonstrated geometric feasibility for correction of excessive tibial plateau angles and was associated with less rotational displacement of the proximal tibial segment relative to the patellar tendon insertion than conventional TPLO and TPLO combined with CCWO. Further cadaveric, biomechanical, and clinical studies are required to evaluate its safety and clinical applicability. Full article

This article examines the terminological contributions of Gaspard Bauhin in his seminal work, “Theatrum Anatomicum” (1605). It is part of a series of articles exploring the development of anatomical terminology following Vesalius. Through linguistic analysis of the original Latin text, the study identifies four models of terminological transformation: (1) passive monosynonymy—the reduction of multiple synonyms to a single standard term (clavicula, scapula); (2) visual standardization—the transformation of descriptive phrases into binary terms through the labels of anatomical illustrations (musculus obliquus superior, musculus obliquus inferior); (3) conservative osteology—preservation of genitive constructions for cranial bones (os Frontis, ossa Syncipitis); (4) implicit consolidation—the establishment of terms with disputed priority (malleus, incus, stapes) by including them in an authoritative systematic text. Statistical analysis of the Index Rerum reveals a 70% binary form in the nomenclature of muscles compared to 38% in the nomenclature of bones, which confirms the selective nature of Bauhin’s standardization. The prescriptive language (vocamus, nominamus) indicates that Bauhin prescribes rather than describes. The study establishes that os frontale, os parietale, and os occipitale do not appear in Bauhin’s active nomenclature (Bauhin 1605, Lib. III, p. 531; Bauhin 1609, pp. 145–47)—a finding that qualifies the broad historiographical attribution of modern anatomical bone terminology to Bauhin (Pretterklieber 2024; Ghosh 2016) and confirms the selective character of his standardization programme. The parallel between Theatrum Anatomicum and Pinax Theatri Botanici (1671) reveals the universal applicability of the genus et differentia principle, anticipating Linnaeus’s binary system (1753). Full article

Traumatic Brain Injuries (TBIs) frequently require cranioplasty procedures to restore skull integrity and protect underlying brain. Conventional cranial implants are often limited by inadequate osteointegration, risk of inflammation, infection, or the need for secondary surgical interventions. In this study, a multifunctional strategy for cranial reconstruction is proposed, combining additive manufacturing, bioactive surface functionalization, and local drug delivery. Porous polylactic acid (PLA) scaffolds were fabricated by Fused Deposition Modelling (FDM) to obtain lightweight structures with controlled porosity. The scaffolds were subsequently functionalized with hydroxyapatite coatings, deposited through sol–gel, to provide osteointegrative properties. To locally modulate post-implant inflammatory responses, a drug delivery system based on polycaprolactone (PCL) microparticles loaded with dexamethasone was developed and entrapped within hydroxyapatite-coated PLA structures. The produced systems were extensively characterized in terms of morphology, mechanical and thermal behavior, structural properties, biological response, and drug release behavior. Results demonstrated that the 3D-printed scaffolds exhibited homogeneous hydroxyapatite coatings, whose continuity and retention were enhanced by NaOH surface pre-treatment. Biological assays demonstrated that HAp coating significantly improved cell viability and osteogenic differentiation, confirming the osteoconductive potential of the scaffolds for craniofacial bone regeneration applications. Dexamethasone-loaded PCL microparticles were successfully integrated into the coated scaffolds, exhibiting controlled drug release, absence of cytotoxicity, and homogeneous distribution within the porous architecture, thereby demonstrating the feasibility of a multifunctional platform combining bone-regenerative and therapeutic delivery functionalities. Overall, the proposed multifunctional scaffolds represent a promising, low-cost and customizable approach for advanced cranioplasty applications, integrating structural support, osteointegration and local anti-inflammatory therapy within a single system. Full article

Cranial cruciate ligament (CrCL) rupture in cats is less common than in dogs, and its optimal treatment remains a subject of debate. This study aimed to evaluate the application of cranial tibial wedge osteotomy (CTWO) as a dynamic stabilization technique in cats with CrCL rupture, describing the technical aspects and clinical outcomes obtained. Five cases with a confirmed diagnosis of CrCL rupture between 2020 and 2024 were included in this study. All patients were treated with CTWO using specific osteosynthesis locking plates designed for use in dogs and a complementary cerclage wire. Radiographic rechecks were performed at 8 and 12 weeks postoperatively, and clinical evaluations were performed 24 h, 8 weeks, 12 weeks, and 6 months postoperatively in every patient. Successful and complete bone healing of the tibial osteotomy was observed in every case. No intraoperative or postoperative complications related to implants or soft tissues were recorded. All cats achieved complete functional recovery without lameness at the last recheck six months after surgery. The technique was performed without significant technical difficulties, providing adequate stability and favorable clinical outcomes in all cases. These preliminary results support the use of CTWO as an effective surgical alternative for the treatment of CrCL rupture in cats. However, further studies with a larger number of cases and a longer follow-up are required to better evaluate its clinical application, outcomes, and influence on osteoarthritis progression in the long term. Full article

Maternal exposure to airborne particulate matter smaller than $2.5$ μm (${\mathrm{PM}}_{2.5}$) has been associated with adverse fetal outcomes, although its effects on intramembranous ossification remain poorly understood. This study evaluated the impact of gestational and pregestational exposure to wood-smoke-derived ${\mathrm{PM}}_{2.5}$ on fetal neurocranial ossification in Sprague–Dawley rats. Females were allocated to four exposure conditions combining filtered air (FA) and non-filtered air (NFA): FA/FA, FA/NFA, NFA/FA, and NFA/NFA. Fetuses were collected at gestational day 21 and analyzed using fetal morphometry, radiography, micro-computed tomography, whole-mount alizarin red skeletal staining, histology, and immunohistochemistry for HIF-1$\alpha$, COL-1, BMP-2, FGF-R1, and TGF-$\beta$. Continuous exposure (NFA/NFA) was associated with reduced fetal weight, shorter crown–rump length, impaired craniofacial mineralization, widened cranial sutural regions, and reduced mineral density, particularly in the occipital and interparietal bones. Histologically, exposed fetuses exhibited abundant osteoid, reduced osteocyte incorporation, and diffuse osteoblastic distribution, consistent with delayed osteogenic maturation. Immunohistochemistry showed increased HIF-1$\alpha$ immunoreactivity, altered TGF-$\beta$ regulation, and reduced COL-1 expression in continuously exposed fetuses, whereas BMP-2 and FGF-R1 showed no significant changes. These findings suggest that maternal exposure to wood-smoke-derived PM_2.5 is associated with delayed fetal neurocranial intramembranous ossification, particularly under continuous exposure. The observed immunohistochemical profile, elevated HIF-1$\alpha$, reduced COL-I, and altered TGF-$\beta$, is consistent with a hypoxia-associated imbalance between extracellular matrix deposition and mineral maturation; however, the underlying mechanistic pathway was not directly functionally tested and should be regarded as a biologically plausible inferential model requiring further experimental validation. Full article

Traumatic fractures are common in small animal emergency care, yet subtle fracture lines may be difficult to identify accurately using routine three-dimensional reconstruction workflows, particularly when access to specialized software is limited. This study describes the use of the open-source platform Three-Dimensional Slicer for computed tomography-based reconstruction and three-dimensional printing in a small dog with cranial trauma, with emphasis on documenting a practical and reproducible workflow through voxel resampling. Imaging data were imported into the software, bone structures were segmented using a rapid workflow, voxel spacing was resampled for smoother surface visualization by volume resampling, and the reconstructed model was processed for physical printing. Digital models of different resolutions were generated within minutes, and a life-size skull model was successfully fabricated using fused deposition modeling in less than three hours at a material cost of under one United States dollar. The enhanced model provided an intuitive representation of fracture morphology and spatial relationships compared with routine reconstruction alone. These findings demonstrate that open-source software combined with low-cost printing can provide a rapid, affordable, and user-friendly approach for practical skeletal reconstruction in small animals, with practical value for fracture assessment, preoperative planning, and broader use in resource-limited veterinary settings. Full article

Background and Objectives: Percutaneous iliosacral screw fixation is a standard treatment for posterior pelvic ring instability and sacral insufficiency fractures. However, conventional transsacral S1 screw fixation is associated with notable complication rates, most commonly implant loosening; dysmorphic sacral anatomy increases the risk of iatrogenic L5 or S1 nerve root injury. This study presents a modified S1 trajectory to engage the high-density bone of the anterior and cranial S1 vertebral body (promontory) by transferring preoperative 3D planning to intraoperative 2D fluoroscopy. Materials and Methods: This retrospective study analyzed implant placements for posterior pelvic ring instability, including high-velocity trauma and fragility fractures of the pelvis (FFPs). Preoperative computed tomography (CT) multiplanar reconstruction defined a modified corridor from a posterior-caudal iliac entry point directed cranially and ventrally into the S1 promontory. The 3D trajectory was transferred intraoperatively using standard 2D fluoroscopy (lateral, anteroposterior, inlet, and outlet views) with the patient prone. In cases of reduced bone quality or intended sacroiliac fusion, 3D-printed titanium implants (triangular or cylindrical threaded, 10.0–13.5 mm outer diameter) were selected over 7.5 mm cannulated screws. Results: Overall, 137 implants were placed in 71 patients: 13 cannulated screws in high-velocity pelvic ring trauma, 72 triangular titanium sacroiliac fusion implants (iFuse Implant System^®, SI-Bone), and 52 threaded titanium fusion implants (iFuse TORQ^®, SI-Bone) in patients with FFP. The modified trajectory consistently engaged the anterior and cranial S1 vertebral body. Postoperative 3D CT confirmed accurate placement of all implants. No iatrogenic nerve injuries or revisions for implant malposition occurred. Mean follow-up was 12 ± 9 months. Conclusions: Preoperative 3D CT planning combined with standard 2D fluoroscopy guided a modified S1 trajectory toward the cranial S1 vertebral body. Accurate and safe implant placement was achieved in the prone position without navigation systems, providing a practical alternative when standard transverse trajectories are limited by narrow bony corridors or sacral or pelvic dysmorphy. Full article

Background: Paranasal sinuses and mastoid air cells have been attributed to multiple functions—such as voice resonance, cranial lightening, and pressure regulation—yet their potential role in local thermal homeostasis remains underappreciated. The thermoregulatory hypothesis, first proposed in the mid-twentieth century, was largely abandoned after the mid-century, when anthropological findings of climate-correlated variation seemed contradictory. Hypothesis: We propose that pneumatized skull regions form a three-component craniofacial biothermal system that maintains thermal stability in the ocular vitreous and vestibular endolymph, two avascular, temperature-sensitive structures that lack intrinsic thermoregulatory capacity. This represents a novel integration that explicitly links paranasal and mastoid pneumatization into a coordinated system that protects sensory organs, distinct from previous brain-cooling hypotheses. Mechanism: The system comprises: (1) passive thermal insulation via air spaces, providing ~15-fold greater thermal resistance than bone; (2) active cold protection via mucosal heat delivery (estimated 2–5 W capacity); and (3) active heat dissipation via evaporative cooling (estimated 0.3–0.5 W capacity). This architecture provides asymmetric protection, with cold buffering exceeding heat dissipation by approximately 5- to 15-fold, consistent with thermodynamic constraints and putative evolutionary priorities. Evidence: Preliminary observations consistent with this hypothesis include the anatomical proximity of pneumatized regions to the vitreous and labyrinth, intranasal selective brain cooling studies, and clinical observations after mastoidectomy showing preserved pressure buffering but reduced vestibular thermal insulation under extreme stimulation. Climate-correlated pneumatization patterns are consistent with bidirectional thermal adaptation. Implications: We present five falsifiable predictions that can be tested with thermographic imaging, pharmacological manipulation, and computational modeling. Validation could inform surgical planning, explain postoperative thermal-sensitivity symptoms, and provide evolutionary insights into craniofacial adaptation. Full article

Background/Objectives: High common carotid artery bifurcation (CCAB) is an anatomic variant relevant to carotid endarterectomy that is associated with an increased risk of cranial nerve injury, particularly hypoglossal nerve injury. This study analyzed CCAB location relative to anterior neck landmarks as a method for categorizing its proximity to critical surgical structures. Methods: Eighty-one formalin-fixed donors were dissected, yielding 159 CCABs. CCAB height was classified relative to six transverse anterior neck planes using superficial anatomic landmarks. Distances from the CCAB to the hypoglossal nerve and angle of the mandible were measured. Superior thyroid (ST) artery origin was also recorded. Results: A majority of CCABs occurred near the hyoid bone, but locations varied between and within donors. CCAB height did not differ significantly by sex or by which side of the neck they were from. Higher CCABs were closer to the hypoglossal nerve and angle of the mandible. When using anterior neck landmarks, there was a strong linear relationship between the height of the CCAB and both the hypoglossal nerve and the angle of the mandible. The hypoglossal nerve looped inferior to the CCAB in 11 cases. ST artery origin varied, with higher CCABs originating from the common carotid artery more often. Conclusions: By using anterior neck landmarks to classify CCAB height, clinicians may establish a more precise definition of high CCAB that incorporates reliable estimates of hypoglossal nerve proximity. This approach may improve preoperative risk assessment, guide surgical selection, and reduce complications. Full article

(1) Background: Integrated bioarchaeological approaches combining osteological and ancient DNA analyses provide powerful insights into health, disease, and population history in past societies. However, the relationship between rare skeletal variations, genetic disorders, and ancestry remains insufficiently explored within single individuals. This study aimed to investigate the combined osteological, paleopathological, and genetic characteristics of a Roman-period individual from southwestern Anatolia. (2) Methods: A multidisciplinary approach was applied to the skeletal remains of an adult male recovered from the Sekköy excavation site. Osteological analysis was conducted to assess cranial morphology, pathological lesions, and dental status. Ancient DNA was extracted from petrous bone under strict contamination control. The hemoglobin beta (HBB) gene was analyzed using Next Generation Sequencing and validated by Sanger sequencing. Y-chromosomal STR analysis was performed to determine paternal lineage. (3) Results: Osteological examination revealed a rare craniovertebral anomaly consistent with a third occipital condyle, along with porotic hyperostosis and extensive antemortem dental pathology, indicating prolonged physiological stress. Genetic analysis identified a heterozygous hemoglobin S mutation (HbAS; rs334), confirmed by both next-generation sequencing and Sanger sequencing, providing direct molecular evidence of hereditary hemoglobinopathy. Y-STR profiling assigned the individual to haplogroup R1b (predicted based on Y-STR data), indicating affiliation with Western Eurasian paternal lineages. (4) Conclusions: Despite the presence of comparable skeletal stress indicators, the integration of osteological and genetic data revealed a complex interaction between anatomical variation, chronic physiological stress, and inherited disease. The co-occurrence of a rare cranial anomaly, HbS mutation, and a defined paternal lineage represents a unique bioarchaeological case. These findings highlight the value of integrating skeletal and molecular approaches to reconstruct individual health profiles in archaeological contexts and demonstrate the methodological potential of interdisciplinary bioarcheological analysis. Full article

Nickel (Ni) is a ubiquitous trace metal, yet its physiological dynamics and dose-dependent roles in skeletal biology remain unclear. Here we combined elemental mapping, cellular assays, multi-omics and mouse models to define how Ni availability modulates osteogenesis. Ni, together with Manganese (Mn), chromium (Cr) and copper (Cu), was readily detectable in serum from both mice and humans. In situ LA–ICP–MS further showed that Ni levels in embryonic calvaria rose significantly across stages and CaO exhibited a consistent upward trend, suggesting coordinated accumulation of Ni with cranial mineralization. In vitro, Ni exerted biphasic effects on bone marrow mesenchymal stromal cells (BMSCs): high-dose Ni (100 μM) suppressed proliferation, elevated ROS, and induced time-dependent upregulation of Hmox1 and Nos2, consistent with escalating oxidative/nitrosative stress. By contrast, low-dose Ni (0.1 μM) enhanced matrix mineralization, whereas this pro-mineralization effect was attenuated at higher concentrations. In vivo, both Ni deprivation and Ni overload impaired bone formation: a Ni-free diet caused trabecular rarefaction and reduced mineral apposition, while high Ni hindered bone development of mice, especially in the early-stage intake. Mechanistically, RNA-seq and Ni-NTA proteomics identified Ni-driven osteogenic transcriptional remodeling and increased Ni-binding proteins, prioritizing integrin-linked kinase (ILK) as a Ni-inducible binder. ILK was required for osteogenic differentiation, and low-dose Ni activated AKT–mTOR signaling in an ILK-dependent manner. Finally, low-dose Ni-pretreated collagen scaffolds enhanced calvarial defect repair. Together, these findings define a narrow physiological window in which Ni supports osteogenesis via ILK–AKT–mTOR, whereas both deficiency and excess disrupt skeletal accrual. Full article

Cranial vault reconstruction is a critical component of care following trauma, decompressive craniectomy, infection, or oncologic resection. Large and complex cranial defects present unique reconstructive challenges, as autologous reconstruction may be limited by donor availability, contour mismatch, and long-term resorption. Consequently, alloplastic materials have become central to contemporary cranioplasty. Advances in imaging, computer-aided design/manufacturing (CAD/CAM), and three-dimensional workflows have enabled increasingly accurate patient-specific reconstruction with improved operative efficiency. This narrative perspective summarizes the evolution and clinical application of commonly used alloplastic materials in cranial vault reconstruction, including titanium, polymethylmethacrylate (PMMA), and hydroxyapatite (HA), with a focused discussion of polyetheretherketone (PEEK). We discuss the design rationale, material properties, and clinical performance of PEEK, emphasizing bone-mimicking elasticity, radiolucency, and compatibility with CAD/CAM workflows. Institutional experience is integrated to contextualize durability, aesthetic restoration, neurologic improvement, infection management, and technical considerations that influence outcomes. Overall, PEEK represents a versatile option for large and complex cranial reconstruction by combining favorable mechanical performance with patient-specific design capability. Continued advances in biomaterials and surgical planning, coupled with rigorous long-term outcome evaluation, will further refine material selection and optimize reconstructive outcomes in cranial vault reconstruction. Full article

An encephalocele is a rare congenital or acquired cranial defect characterized by herniation of intracranial tissue through a defect in the skull base. In human and veterinary medicine, these lesions are frequently associated with abnormalities in neural tube development or structural weakness of the cranial bones, resulting in the protrusion of brain tissue and meninges through anatomical openings such as the cribriform plate. Although this condition has been extensively described in human neurosurgical research, reports on dogs remain limited, and the clinical significance of surgical intervention in cases with communication to the nasal cavity remains unclear. In this case, a young American Cocker Spaniel presented with seizures, prompting advanced diagnostic evaluation. Magnetic resonance imaging revealed a protrusion of the intracranial tissue through a defect in the cribriform plate extending into the nasal cavity. Surgical resection of the protruding tissue was performed, followed by skull base reconstruction. Histopathological examination demonstrated nervous tissue with chronic inflammatory changes without evidence of neoplasia. The patient recovered uneventfully after surgery and remained free of seizure recurrence during follow-up. Surgical management may represent a viable treatment option for seizure disorders in young dogs, particularly when persistent cranio-nasal communication is present, and provides a clinically relevant comparative model for similar cranial base defects described in human pathology. Full article