Search Results (1,434)

Background: COVID-19 is primarily a respiratory disease, but increasing evidence suggests possible oral and maxillofacial complications. This study presents a case series of post-COVID maxillary osteonecrosis (PC-RONJ) cases from western Romania and explores the possible association between SARS-CoV-2 infection, its treatment, and this complication. Methods: We conducted a multicenter retrospective case series of two patients with recent PCR-confirmed SARS-CoV-2 infection who subsequently developed maxillary osteonecrosis (ONC) between 2021 and 2023. Clinical examination, CT imaging (including 3D reconstructions), and ENT assessment were used to assess the severity of the disease. All medical records were reviewed to identify comorbidities, details of COVID-19 treatment, and the appearance of maxillofacial symptoms. Results: Both patients had been hospitalized for severe COVID-19 and treated according to the national protocol with systemic corticosteroids, oxygen therapy, anticoagulation, and antivirals. CT scans revealed marked osteolytic destruction of the maxilla and maxillary sinus walls, with extension toward adjacent facial bones. Microbiological analysis revealed a complex polymicrobial profile, including Gram-positive and Gram-negative bacteria as well as opportunistic fungal species, consistent with a chronic biofilm-associated infectious process. Patients received surgical treatment, followed by local care and, in both cases, prosthetic rehabilitation with maxillary obturators, which improved speech, chewing, and oral function. Conclusions: This case series suggests a possible association between severe COVID-19, its treatment, and subsequent maxillary osteonecrosis in susceptible patients; however, the small number of cases precludes causal inference. To our knowledge, this is the first Romanian report describing such cases in patients without prior antiresorptive therapy. These findings highlight the need for careful use of systemic corticosteroids and vigilant post-recovery monitoring of maxillofacial complications. Further studies are required to clarify the underlying mechanisms and risk factors. Full article

The manuscript details the influence of high-temperature and high-shear processing, as well as radiation sterilization, on properties of bioresorbable and osteoconductive, patient-tailored alloplastic scaffolds for guided bone regeneration. Functionalized poly(l-lactide-co-d,l-lactide) copolymer filled with hydroxyapatite was used to produce two personalized implants for upper and lower jaw reconstruction via 3D printing. Morphology analysis (SEM, µCT), gel permeation chromatography, and thermal analysis quantified the effects of melt processing and sterilization on chain structure. Physical properties of sterilized parts, such as hardness and density, proved suitable for bone implants. Removal of the upper jaw implant after 4 months and of the lower jaw substitute after 18 months enabled monitoring of bioresorption and tissue regrowth over time. Gradual overgrowth of the implants with human tissue, initiated by the osteoconductive filler, was observed, along with time-dependent polylactide degradation, showing up to 92% molar mass reduction. The medical procedures confirmed safety, nontoxicity, non-allergenicity, and, most importantly, the tissue-forming properties of the polylactide-based formulation. Full article

Ossification of the vascular pedicle following fibula free flap (FFF) reconstruction is an uncommon and typically asymptomatic complication. Symptomatic cases requiring intervention are rare. We report a 29-year-old man with anterior maxillary osteosarcoma who underwent tumor resection followed by reconstruction with an osteocutaneous FFF. Calcification within the surgical site region was noted on imaging at two months after fibular reconstruction. By five months, he developed progressive trismus and pain with mastication. Computed tomography demonstrated a calcified structure extending from the mandible to the reconstructed maxilla along the flap pedicle, raising concern for tumor recurrence. Surgical excision was performed, and histopathology revealed benign woven bone without evidence of malignancy. Postoperatively, trismus improved, and flap viability was preserved. Retained periosteum during FFF harvest maintains osteogenic potential and may result in pedicle ossification. In symptomatic patients, particularly when recurrence is suspected, surgical resection is both diagnostic and therapeutic. Full article

Background: Aneurysmal bone cysts (ABCs) of the proximal humerus in children are rare, locally aggressive lesions associated with substantial recurrence rates and risk of structural instability. Conventional treatment by curettage and bone grafting is often limited by recurrence, while selective arterial embolization (SAE) alone may not provide sufficient structural support. This study evaluates a single-stage treatment strategy combining embolization and structural reconstruction to address both the vascular and mechanical components of the disease. Methods: A retrospective analysis was performed on 12 pediatric patients (median age 9 years) with proximal humerus ABCs treated between 2020 and 2024. All patients underwent a standardized single-stage protocol consisting of preoperative SAE, intralesional resection with high-speed burr, and reconstruction using an allogeneic fibula graft combined with cancellous bone augmentation. Radiological consolidation, recurrence, and functional outcomes were assessed. Associations between prior surgery, cyst size, and recurrence were analyzed. Results: Primary consolidation was achieved in 75% of patients, with an overall healing rate of 91.7% after secondary interventions. Recurrence occurred in 16.7% of cases and was significantly associated with prior surgical treatment (p = 0.045). No significant correlation was found between cyst size and recurrence (p = 0.151). At final follow-up (median 8.5 months), all patients demonstrated complete healing according to the modified Neer classification following completion of treatment. Functional outcomes were favorable, with 91.7% of patients regaining full range of motion and no neurovascular complications observed. Conclusions: The presented single-stage approach combining SAE, intralesional resection, and structural allograft reconstruction addresses both the vascular supply and mechanical instability of proximal humerus ABCs. This strategy demonstrated high healing rates and favorable functional outcomes, with acceptable recurrence rates in this cohort while avoiding donor site morbidity. It represents a practical and effective treatment concept for this rare pediatric condition. Full article

Background/Objectives: Lisfranc joint injuries are complex midfoot pathologies frequently associated with subtle radiologic findings and delayed diagnosis. Although ligamentous disruption is considered the primary mechanism, the contribution of intrinsic osseous morphology remains insufficiently investigated. Previous studies have primarily relied on two-dimensional measurements and limited morphometric parameters. Therefore, this study aimed to provide a comprehensive three-dimensional (3D) computed tomography (CT) based morphometric evaluation of the medial and central columns of the Lisfranc joint and to determine whether specific bony parameters are associated with injury predisposition. Methods: A total of 48 CT scans, including 23 from patients with Lisfranc joint injuries and 25 from healthy controls without midfoot trauma, were retrospectively analyzed. For both groups, 3D models of the first three metatarsals (M1–M3) and cuneiforms (C1–C3) were reconstructed to measure bone length, articular surface areas, volumes, M1–M2/M2–M3 depth differences, and dorsal step-off (dorsal subluxation of M2 relative to C2). Correlations of these measurements with M2 length were additionally assessed in each group. Results: Comparisons between injury and healthy control groups revealed no significant differences in bony morphometrics (p > 0.05). Correlation analysis showed that a longer M2 were associated with greater cuneiform volumes and larger metatarsal articular surface areas (p < 0.05). Conclusions: This comprehensive 3D morphometric assessment of the Lisfranc joint indicates that intrinsic bony anatomy alone is unlikely to represent a primary predisposing factor for Lisfranc injuries. The observed positive relationship between M2 length and cuneiform articular surface areas and volumes demonstrates structural interdependence within the medial and central columns. Overall, injury susceptibility does not appear to be explained by variations in osseous morphology alone. Full article

Background: Long-bone non-unions complicated by osteomyelitis remain a major reconstructive and healthcare challenge, particularly in resource-limited settings with a high prevalence of multidrug-resistant (MDR) pathogens. Conventional staged management is associated with a prolonged treatment burden, repeated procedures, and delayed functional recovery. This study evaluated the clinical, radiological, functional, and short-term safety outcomes of a single-stage approach using custom-threaded antibiotic-coated locking nails (TACLNs) in a high-resistance cohort. Methods: This prospective single-center cohort study enrolled 30 adults with osteomyelitis-associated femoral or tibial nonunion at a tertiary hospital in Peshawar, Pakistan. All patients underwent radical debridement and single-stage stabilization with a chest tube mold TACLN loaded with vancomycin and gentamicin, with culture-directed adjunctive antibiotics for resistant organisms. Outcomes were assessed at baseline, Weeks 3 and 6, and Month 6 using inflammatory markers, RUST score, VAS pain, EQ-5D-5L, ASAMI criteria, and return to work or usual activity. No formal sample size calculation was performed, and this study was exploratory in nature. Results: The cohort (mean age 44.9 ± 9.9 years) had a challenging microbiological profile, with 40.0% MDR and 13.3% extensively drug-resistant (XDR) infections. By Month 6, short-term infection control was achieved in 96.7% of patients, with significant reductions in ESR and CRP (both p < 0.001). Radiographic union was achieved in 90.0% of cases at a mean of 18.6 weeks, and the mean RUST score improved from 4.87 to 10.43 at the final follow-up. The VAS pain decreased from 5.23 at week 3 to 0.73 at month 6, EQ-5D-5L improved from 0.39 to 0.84, and 90.0% returned to work or usual activity by month 6. No cement debonding, implant failure, or nephrotoxicity was noted. Conclusions: In this single-arm exploratory cohort, TACLNs were associated with favorable short-term infection control, radiographic union, and functional recovery in osteomyelitis-associated long-bone nonunion, including in an MDR/XDR setting. The independent contribution of the threaded core design cannot be established. Larger multicenter comparative studies with longer follow-ups are needed to confirm the durability and implementation feasibility. Full article

Background/Objectives: Temporal bone surgery in children is technically challenging due to their smaller anatomical structures, developmental differences, and the closer proximity of critical neurovascular structures. The limited availability of conventional training materials and pediatric cadaveric specimens has led to greater enthusiasm for simulation-based methods. The aim of this systematic review was to identify existing otologic simulation models and evaluate their anatomical accuracy, teaching effectiveness, and supporting evidence. Methods: In accordance with PRISMA guidelines, the PubMed, Embase, Scopus, and Cochrane Library databases were searched for studies reporting simulation tools for pediatric otologic surgery. Articles describing three-dimensional printed (3DP) models, virtual reality (VR) platforms, cadaver specimens, and animal models were included. Studies focusing on children and providing educational outcomes were selected. The extracted data were synthetized and analytically discussed. Results: Thirteen studies met the inclusion criteria: nine on 3DP models and four on VR environments. No research involving cadavers or animals was identified. 3DP models exhibited consistent anatomical accuracy and notable educational advantages. Five studies used surveys for their evaluations, and three relied on expert observer assessments. The studies including validation analyses showed a high correlation between printed models and computed tomography (CT) images. VR systems supported anatomical reconstruction and segmentation tasks, as well as guided simulation exercises. However, most of the research consisted of feasibility studies with limited participant groups. Conclusions: Simulation-based training with 3DP and VR models could be ethical and accurate methods for obtaining relevant skills in pediatric otologic surgery. The reviewed data suggest that these tools may be suitable as a first-line step within an integrated, multimodal training pathway prior to direct patient contact. Full article

Bone marrow(BM) is the primary site of hematopoiesis, supporting the self-renewal and differentiation of hematopoietic stem cells (HSCs). Its function depends on a highly complex microenvironment composed of stromal cells, vascular networks, extracellular matrix components, and dynamic biophysical signals. Traditional two-dimensional culture systems and animal models fail to adequately recapitulate the spatial architecture and dynamic regulatory processes of the human bone marrow niche, thereby limiting in-depth investigations into hematopoietic regulatory mechanisms, disease pathogenesis, and drug-induced bone marrow toxicity. In recent years, advances in microphysiological systems (MPS) have provided novel engineering approaches for the in vitro reconstruction of the bone marrow microenvironment. This review systematically summarizes current construction strategies for bone marrow MPS, including three-dimensional self-organized bone marrow organoids and microfluidic bone marrow-on-a-chip platforms. Particular attention is given to the roles of key cellular components, biomaterial scaffolds, vascularized architectures, and dynamic perfusion systems in biomimetic bone marrow engineering. In addition, we discuss strategies for constructing more complex models, such as vascular niches, vascularized bone tissue constructs, and bone metastasis models. Bone marrow MPS more faithfully recapitulate the hematopoietic microenvironment and provide a physiologically relevant in vitro platform for hematopoietic research, disease modeling, and drug evaluation, thereby supporting future advances in precision and regenerative medicine. Full article

Background: Wrist osteomyelitis caused by Scedosporium apiospermum is exceedingly rare. Its indolent course and destructive potential may result in extensive bone loss and pose substantial diagnostic and therapeutic challenges. Methods: We report a case of chronic wrist osteomyelitis caused by Scedosporium apiospermum in a 68-year-old kidney–pancreas transplant recipient. Results: Following diagnosis, systemic antifungal therapy with voriconazole was initiated, and multiple surgical debridements were performed to achieve local disease control, resulting in a large defect of the carpus and distal forearm. Hand salvage was attempted using an osteocutaneous triple-barrel fibula flap. The postoperative course was complicated by congestion of the fibula skin island, which was managed with leech therapy. Subsequent infection with a multi-resistant Aeromonas spp. and Morganella morganii led to flap necrosis, ultimately requiring transradial forearm amputation. Conclusions: Destructive Scedosporium apiospermum osteomyelitis in immunocompromised patients is a major challenge for reconstructive surgeons. Interdisciplinary management is essential as mold eradication is only achievable through a combined surgical and antimicrobial approach. In advanced destructive osteomyelitis, the choice between limb salvage and amputation should be individualized, considering patient comorbidities, reconstructive risk, and patients’ preferences. This case highlights the importance of balancing careful indication and patient counseling in complex clinical scenarios. Full article

Background/Objectives: Chondromyxoid fibroma (CMF) is a rare benign cartilaginous bone tumor, accounting for less than 1% of all primary bone tumors. Although CMF most commonly arises in the metaphysis of long bones, involvement of the phalanges of the toes is uncommon. We report a pediatric case of CMF arising in the distal phalanx of the second toe that recurred four years after initial surgical treatment and discuss its management. Methods: A 10-year-old girl presented with a painless mass in the distal phalanx of the second toe. Imaging studies demonstrated an expansile osteolytic lesion with cortical thinning, showing a somewhat aggressive radiologic appearance. Intralesional curettage and debridement were performed to preserve the digit, and the bone defect was reconstructed using allogenic cancellous bone graft and demineralized bone matrix. Histopathological examination confirmed the diagnosis of CMF. Results: Four years later, the patient returned with progressive enlargement of the lesion, indicating tumor recurrence. Because of the recurrent nature of the tumor and progressive cosmetic deformity and recurrence-related anxiety, distal phalangectomy was performed. At the one-year follow-up, the patient showed no evidence of recurrence and maintained satisfactory functional and cosmetic outcomes. Conclusions: CMF of the toe phalanx may show delayed recurrence after curettage, requiring prolonged radiologic surveillance. In recurrent cases, definitive resection should be considered based on a combination of oncologic, anatomic, and patient-centered factors, with distal phalangectomy providing reliable local control in anatomically expendable digits. Full article

Hematopoietic stem and progenitor cells (HSPCs) in the bone marrow are highly vulnerable to radiation-induced damage. Systematic delineation of lineage-specific transcription factor (TF) programs, together with in silico perturbation analyses, provides a valuable approach for identifying regulators capable of accelerating hematopoietic reconstruction after irradiation. Here, using single-cell RNA sequencing (scRNA-seq), we characterized the dynamics of HSPCs at both cellular abundance and transcriptional regulation levels following irradiation and used in silico TF perturbation to predict their effects on lineage commitment. We found that granulocyte–macrophage progenitor (GMP) differentiation is consistently prioritized after irradiation, accompanied by enhanced activity of proliferation-associated drivers. Network-based TF profiling identified Tcf7l2 as a previously unrecognized regulator of early lymphoid differentiation. In silico perturbation further functionally predicted TFs driving differentiation in HSPCs after irradiation, and Hsf1, a factor with pharmacological activation potential, was selected for validation via in vivo celastrol treatment and in vitro knockdown. Collectively, our findings uncover the transcriptional programs governing HSPC lineage biases after radiation exposure and highlight the utility of in silico TF perturbation as a strategy for guiding the therapeutic interventions for radiation-induced hematopoietic injury. Full article

Background and Objectives: Ventral stabilization of thoracolumbar spine fractures can be achieved using different interbody reconstruction techniques, including titanium cages, vertebral body replacements (VBR), and autologous pelvic bone grafts (APBG). Although all approaches aim to restore anterior column stability and alignment, comparative data on long-term patient-reported outcomes remain limited. The objective of this study was to compare long-term patient-reported wellbeing following ventral stabilization using these three techniques. Materials and Methods: A retrospective, non-randomized single-center cohort study with prospective follow-up was analyzed. Treatment allocation was indication-based. Ninety-one patients treated between 2008 and 2018 underwent ventral stabilization using cage implantation (n = 12), vertebral body replacement (n = 45), or autologous pelvic bone grafting (n = 34). Clinical outcome was assessed at least 12 months postoperatively using a modified Visual Analog Scale Spine Score (VAS-Spine). Statistical analysis included linear and ordinal regression adjusted for age and sex. Potential baseline differences between groups were considered in the interpretation of the results. Results: Sixty-three patients (mean age 52 ± 15 years; 41% female) completed follow-up. The mean VAS-Spine score was lowest after cage implantation (2.7 ± 3.6), followed by VBR (3.9 ± 2.8) and APBG (4.9 ± 1.8; p* = 0.021). The observed difference between cage and APBG approached the minimal clinically important difference reported for VAS-based measures. Patients treated with cage implantation reported less pain during rest and activity and fewer limitations in daily life. No significant differences were observed regarding age or sex. Conclusions: In this observational cohort, cage implantation was associated with more favorable patient-reported outcomes compared with VBR and APBG. Autologous pelvic bone grafting was associated with worse patient-reported outcomes, potentially related to donor-site morbidity. Given the non-randomized design and potential confounding, these findings should be interpreted as associative and hypothesis-generating. Full article

3D bird pose estimation plays a pivotal role in ecological conservation research. However, it remains a formidable challenge due to extensive joint deformation, severe self-occlusion, and the scarcity of 3D ground truth data. Therefore, practical solutions typically rely on accurate 2D keypoint detection from monocular images and subsequent 3D lifting. Although the High-Resolution Network (HRNet) has established a benchmark in 2D pose estimation by preserving high-resolution feature representations, its architecture, which relies on small convolution kernels, faces difficulties in capturing the global long-range dependencies necessary to resolve severe occlusions. To address these deficiencies, the core contributions of this work are summarized as follows: (1) We design a Gated LS-Block with a partial channel gating strategy to decouple channel mixing from spatial mixing, and extract global long-range dependencies via the proposed Large–Small Convolution (LSConv) to minimize feature redundancy. (2) We embed this block into Stage 2 of HRNet, enhancing multi-scale feature learning while slightly reducing model parameters and computational overhead; (3) To alleviate the ill-posed nature of monocular 3D lifting without paired supervision, we develop an unsupervised 3D reconstruction algorithm. Experimental results on the Animal Kingdom dataset demonstrate that our method achieves a 0.9% improvement in PCK@0.05 while reducing GFLOPs by 3.3%. These results verify that the proposed architecture enhances the model’s representation capability for bird poses while ensuring efficient inference. Meanwhile, we validate the applicability of the proposed 3D reconstruction algorithm via qualitative experiments, and further demonstrate that our unsupervised 3D lifting algorithm successfully preserves low symmetry error and robust bone length consistency with proxy metrics. Full article

The challenge of substituting bone defects necessitates the search for effective biomaterials based on biopolymer composites with biocompatible fillers. A promising approach in bone tissue engineering is the use of regenerative scaffolds based on polyhydroxyalkanoates (PHAs), specifically poly(3-hydroxybutyrate)—P(3HB), which are characterized by high biocompatibility and osteoinductive potential. In this study, we evaluate the changes in the mechanical, thermal, and morphological properties of P(3HB) within P(3HB)-copolymers/HA, P(3HB)/CS, P(3HB)/PLA/CS, and P(3HB)/PLA/HA composites. These materials, containing various filler contents (up to 70 wt.% of HA–hydroxyapatite or CS–chitosan), were obtained using melt extrusion compounding. It is shown that the modification of biopolymer matrices promotes a decrease in melting temperature, improvement of mechanical characteristics, and an increase in material elasticity. At high filler concentrations, nanoparticle agglomeration and a deterioration of physical-mechanical properties were observed. It was established that a content of 10–20 wt.% of nano-hydroxyapatite and chitosan is optimal, as these composites most closely match the mechanical properties of bone tissue. The results obtained indicate the high potential of the developed nanocomposites for the creation of biodegradable implants in reconstructive orthopedics. Full article

Background: The optimal timing of cranioplasty (CP) after decompressive craniectomy (DC) remains debated. Early reconstruction may enhance neurological recovery through restoration of cerebral perfusion and cerebrospinal fluid dynamics, yet concerns persist regarding postoperative complications. Objective: To evaluate the impact of early versus delayed cranioplasty on neurological outcomes and postoperative complications in adults following decompressive craniectomy. Methods: A systematic review was conducted in accordance with PRISMA guidelines (PROSPERO ID: CRD420251123808). PubMed, OVID, and Web of Science were searched for studies published between January 2017 and December 2025. Eligible studies compared early and delayed CP in adults and reported neurological outcomes and/or complications. Results: Twenty-one retrospective cohort studies including 8462 patients were analyzed. Neurological improvement was observed in both groups across multiple validated scales (GOSE, GOS, GCS, mRS, BI, FIM, NIHSS, MMSE). Early CP was consistently associated with superior recovery, including higher one-year Barthel Index improvement (74.1% vs. 54.8%), greater FIM gains (7.31% vs. 4.66%), and higher composite recovery rates (95.6% vs. 80.0%). No study demonstrated superior recovery with delayed CP. Infection, hydrocephalus, and seizure rates were comparable between groups. However, hematoma (21% vs. 10.4%) and hygroma (7.49% vs. 4.73%) were more frequent after early CP, although hematoma rates were influenced by a large database study. Bone flap resorption was less frequent with early CP (1.44% vs. 6.26%). Conclusions: Early cranioplasty is associated with improved neurological recovery but carries an increased risk of select complications, particularly hematoma and hygroma, representing a clinically relevant trade-off. Delayed CP does not demonstrate overall superior safety due to higher bone flap resorption. Timing should be individualized, and prospective multicenter studies with standardized definitions are needed. Full article