Enhancing osteoblast differentiation and bone repair: The priming effect of photobiomodulation on adipose stromal cells.

Cellular therapy using adipose tissue-derived mesenchymal stromal cells (at-MSCs) has garnered attention for the treatment of bone defects. Therefore, preconditioning strategies to enhance the osteogenic potential of at-MSCs could optimize cell therapy outcomes, and photobiomodulation (PBM) therapy has emerged as an effective, noninvasive, and low-cost alternative. This study explored the impacts of PBM on at-MSCs differentiation and the subsequent repair of bone defects treated with cell injection. Rat at-MSCs were cultured and irradiated (at-MSCsPBM) following the PBM protocol (660 nm; 20 mW; 0.714 W/cm2; 0.14 J; 5 J/cm2). Cellular differentiation was assessed based on the expression of gene and protein markers. Reactive oxygen species (ROS) were detected using fluorescence. At-MSCsPBM were injected into 5-mm calvarial lesions, and bone formation was analyzed using micro-CT and histological evaluations. At-MSCs were used as control. Data were analyzed using the ANOVA or t-test. At-MSCsPBM exhibited high levels of gene and protein runt-related transcription factor-2 (Runx2) and alkaline phosphatase (Alp) expression. PBM increased ALP activity and significantly reduced ROS levels. In addition, PBM increased the expression of Wnt pathway-associated genes. In vivo, there was an increase in the morphometric parameters, including bone volume, percentage of bone volume, bone surface area, and trabecular number, in at-MSCsPBM-treated defects compared with those in the control. These findings suggest that PBM enhances the osteogenic potential of at-MSCs, thereby supporting the advancement of improved cellular therapies for bone regeneration.

Infected Post-traumatic Bone Defect of the Knee using Bipolar Osteochondral Allograft and 3D Printing: A Case Report.

Introduction: Transplantation with fresh cadaveric osteochondral allograft (FOCA) is frequently used in defects of the femoral condyle and tibial plateau to preserve the knee joint. However, the use of FOCA in bipolar lesions remains controversial in cases with bipolar defects and a history of infection. Case Report: We present a 21-year-old male patient with a massive post-traumatic osteochondral defect of the lateral compartment of the knee and a history of infection, treated by a two-stage approach. In stage 1, infection was eradicated, and joint function recovered with aggressive debridement, polymethyl methacrylate beads, bone cement spacers, and Judet's quadricepsplasty. In stage 2, transplantation was performed with a bipolar FOCA. All treatments were planned using 3D-printed models. Conclusion: The two-stage approach and 3D planning can increase the chances of transplant success by preparing the future allograft bed and obtaining an optimal match between the cadaveric allograft and the patient's defect in cases with potential contraindications, such as a bipolar lesion in the femoral condyle and tibial plateau and a history of infection. A combined approach may lead to a more beneficial outcome for the patient to preserve joint function and improve quality of life.

The polymicrobial infection affects the infection recurrence rate (not failure) in treating femoral and tibial bone defects with the Masquelet technique-a comparative retrospective analysis of 54 patients with mono- and polymicrobial infections.

INTRODUCTION: This study evaluated whether polymicrobial infection affects reoperation rates due to infection recurrence and treatment failure with the Masquelet technique in infected posttraumatic segmental bone defects of the femur and tibia. METHODS:  We retrospectively analyzed patients treated between 2012 and 2021 in two trauma referral centers. We evaluated demographic data, injury, treatment, infection recurrence, failures, and bone healing rates according to whether the infection was mono- or polymicrobial. After uni-bivariate analysis between patients with polymicrobial and monomicrobial infection, we identified the variables associated with infection recurrence and failure through multivariate analysis. RESULTS:  We analyzed 54 patients, 30 (55.55%) with tibial and 24 (44.44%) femoral segmental bone defects, with a mean follow-up of 41.7 ± 15.0 months. Forty-four (81.48%) presented monomicrobial, and 10 (18.51%) polymicrobial infections. Comparatively, the need for soft tissue reconstruction and the infection recurrence rate was significantly higher in patients with polymicrobial infections. There was no significant difference in the failure rate (20 vs. 6.81% p = 0.23). Multivariable logistic regression analysis identified the polymicrobial infection as the only independent variable associated with infection recurrence (Odds Ratio = 11.07; p = 0.0017). CONCLUSION:  Our analysis suggests that polymicrobial infection is associated with a higher risk of infection recurrence in treating the femur and tibia segmental bone defects with the Masquelet technique. This information can help surgeons to inform patients about this and give them a realistic expectation of the outcome and the possibility of reoperation.

Condylar femoral arthroplasty with bone cement as a salvage measure in open fracture with articular bone defect in a young patient.

Open fractures often require complex treatments, especially those with joint involvement or critical bone defects. Managing both combined injuries present even greater challenges and is not without complications. We present the case of a young patient with an open fracture of the femoral condyle and loss of bone stock in the articular surface. In this case, a combined osteosynthesis approach was employed, utilizing cannulated screws and a femoral condyle arthroplasty with bone cement as a salvage measure, allowing a favorable clinical and functional outcome at the 3-year follow-up. This technique serves as a simple, reproducible, and cost-effective alternative for transient or potentially definitive management in such cases.

Split crest con colocación simultánea de implantes en sector anterior: reporte de un caso / Split crest with simultaneous placement of implants in the anterior sector: a case report

La pérdida ósea en el sector anterior, ya sea por un defecto horizontal, vertical o combinado, actualmente es un desafío, no sólo por la integración del implante, sino por la estética involucrada. Entre las técnicas de regeneración ósea que permiten solucionar estos defectos, cabe destacar la técnica de expansión de crestas. Se presenta el caso de una paciente de 58 años con reborde atrófico, que se sometió a la expansión de crestas con colocación simultánea de implantes en sector anterior, con xenoinjerto previo a técnica de expansión de crestas con piezoeléctrico, colocación simultánea de implantes Narrow Connection SLActive Straumann. Se logró ganancia ósea y estabilidad primaria de los implantes, sin complicaciones. En escenarios seleccionados, la técnica de expansión de crestas de manera predecible permite ganancia de hueso horizontal adecuada, el éxito de los implantes con tasa de supervivencia y mínimas complicaciones intra y postoperatorias (AU)

Bone loss in the anterior sector, both a horizontal, vertical or combined defect is a challenge today; not only for the integration of the implant but also the aesthetic involved. There are techniques of bone regeneration that help us to solve this type of defects, among them we should highlight the crest expansion technique. We present the case of a 58-year-old patient with atrophic flange, who underwent the expansion of crests with simultaneous placement of implants in the anterior sector, with xenograft prior to the piezoelectric crest expansion technique, Simultaneous placement of Narrow Connection SLActive Straumann implants, bone gain and primary stability of the implants were obtained, without complications. In selected scenarios, the crest expansion technique could be considered a predictable approach that demonstrates a high implant survival rate, adequate horizontal bone gain, and minimal intra- and postoperative complications (AU)

Bioglass/collagen scaffolds combined with bone marrow stromal cells on bone healing in an experimental model in cranial defects in rats.

This study aimed to develop bone regenerative therapeutic strategies, based on the addition of bone marrow stromal cells (BMSC) on bioglass/collagen (BG/COL) scaffolds. For this purpose, an in vivo study was conducted using tissue response of the BG/COL scaffolds combined with BMSC in a critical-size defects. Wistar rats were submitted to the surgical procedure to perform the cranial critical size bone defects and distributed in four groups (20 animals per group): Control Group (CG) (rats submitted to the cranial bone defect surgery without treatment), Bioglass Group (BG) (rats treated with BG), BG/COL Group (rats treated with BG/COL) and Bioglass/Collagen and BMSC Group (BG/COL/BMSC) (rats treated with BG/COL scaffolds enriched with BMSCs). Animals were euthanized 15 and 30 days after surgery. Scanning electron microscopy, histopathological and immunohistochemistry analysis were used. SEM analysis demonstrated that porous scaffolds were obtained, and Col fibers were successfully impregnated to BG matrices. The implantation of the BMSC on BG/COL based scaffolds was effective in stimulating newly bone formation and produced an increased immunoexpression of markers related to the bone repair. These results highlight the potential of BG/COL scaffolds and BMSCs to be used as a therapeutic approach for bone regeneration.

Outcomes of Open Bankart Repair Plus Inferior Capsular Shift Compared with Latarjet Procedure in Contact Athletes with Recurrent Anterior Shoulder Instability.

Background: Open Bankart repair plus inferior capsular shift (OBICS) and Latarjet procedure (LA) are considered appropriate treatment alternatives for high-performance athletes. The purpose of this study was to evaluate the functional outcomes and recurrence rate of each surgery. Our hypothesis: there were no differences between the two treatments. Methods: A prospective cohort study was conducted with n=90 contact athletes divided into two groups of 45 patients. One group was treated with OBICS, and the other one with LA. The mean follow-up period was 25 (24-32) months for the OBICS group and 26 (24-31) months for the LA group. Primary functional outcomes of each group were assessed at baseline, six months, one year, and two years after surgery. The functional outcomes were also compared between the groups. The evaluation tools used were the Western Ontario Shoulder Instability score (WOSI) and the American Shoulder and Elbow Surgeons scale (ASES). In addition, recurrent instability and range of motion (ROM) were also evaluated. Results: In each group, significant changes were found in the WOSI score and ASES scale from pre-op to postop. However, there were no significant differences between the functional outcomes of the groups at the final follow-up (P-values 0.73 and 0.19). Three dislocations and one subluxation (8.8%) were reported in the OBICS group, and three subluxations were reported in the LA group (6.6%), revealing no significant differences between the groups (P=0.37). Moreover, there were no significant differences between preoperative and postoperative ROM in each group or in terms of external rotation (ER) and ER in 90º abduction between the groups. Conclusion: No differences were found between OBICS and LA surgery. Both procedures can be indicated according to the surgeon's preference to reduce recurrence rates in contact athletes with recurrent anterior shoulder instability.

Definitive fixation in the first stage of the induced membrane technique for septic segmental bone defects. Why not?

Background: Infected segmental bone defects (I-SBD) are challenging and complex to manage. This study aimed to show the outcomes achieved in I-SBD of the femur and tibia, treated with the induced membrane technique performing a definitive bone stabilization in the first stage. Methods: We retrospectively reviewed 30 patients with infected non-articular segmental bone defects of the femur (n = 11) and tibia (n = 19), operated consecutively between January 2015 and May 2021. The need for fixation exchange, bone defect length, allo/autograft ratio used, bone healing, reoperation (discriminating between mechanical and infection-related causes), and failure rates (graft resorption or nonunion) were recorded. Results: Fixation in the first stage was performed with 28 (93.33%) intramedullary nails, ten coated with antibiotic cement, and 2 (6.67%) locked plates. None were removed during the second stage of the technique. The mean length of the bone defects was 5cm (range 3.5-12). The most commonly used allo-/autograft ratio was 50-50. The bone healing rate was 93.33% (n = 28), with a median follow-up of 7 months (range 3-12). The reoperation rate due to mechanical instability was 3.33% (n = 1) and for recurrence of infection was 10.0% (n = 3). The overall failure rate was 6.67% (n = 2). The median follow-up was 42 months (range 12-85). Conclusion: Masquelet technique appears feasible and effective in treating infected segmental bone defects of the femur and tibia. Definitive fixation at the first stage showed a success rate of 93.33%, with a re-operation rate of 10.0% related to infection.

[Stafne's bone cavity in a venezuelan population. Prevalence study]. / Cavidad ósea de Stafne en una población venezolana. Estudio de prevalencia.

Objective: To determine the prevalence of the Stafne´s bone cavity in a Venezuelan population and to characterize it radiographically. Method: Descriptive and cross-sectional study. Of 500 panoramic radiographs, those that had radiolucent images in the mandible, circumscribed and not associated with any dental organ, as well as those that could correspond to the mandibular fossa, were selected. Results were collated and discrepancies resolved by consensus. The selected ones were characterized radiographically. The variables were compared using the student's t test for equality of means, applying the Levene test, values of p <0.05 were considered statistically significant. Results: Of the 500 radiographs evaluated, 22 presented images corresponding to deep mandibular fossa or Stafne bone cavities, which represented 4.4%. Of which 5 presented bilaterally (22.7%) and 17 (77, 3%) unilocularly. Among the radiographic characteristics studied, images located in the posterior area (81.81%), without sclerosis (54.54%), continuous to the basal mandibular area, round shape (59.09%) and partial radiolucency (72%) were presented with a higher prevalence). They were more common in male patients with 63.63%. Conclusions: Our results show a higher prevalence of Stafne's bone cavity in a Venezuelan population than that reported in other studies in other populations.

Efeitos de um biomaterial de origem vegetal (equisetum hyemale) associado a hidrogel contendo ácido hialurônico na regeneração de defeito ósseo em maxila: um estudo preliminar / Effects of a plant-derived biomaterial (Equisetum hyemale) associated with a hyaluronic acid-containing hydrogel on the regeneration of a bone defect in the maxilla: a preliminary study

O tecido ósseo é um tecido naturalmente capaz de se autorregenerar. Entretanto, defeitos ósseos de maiores dimensões têm tal processo dificultado e, em situações de difícil reparação espontânea necessitam de auxílio de enxertos ou materiais apropriados para dar suporte à neoformação óssea. Hidrogéis são excelentes materiais a serem utilizados para esse fim, uma vez que são capazes de mimetizar a maioria das propriedades dos tecidos conjuntivos. Recentemente, despertou-se um interesse significativo no desenvolvimento de hidrogéis híbridos que pudessem ser utilizados em várias aplicações biomédicas. Uma diversidade de partículas é combinada a esse hidrogéis resultando em melhores propriedades. Dessa forma, este estudo tem como objetivo avaliar a influência de um scaffold contendo ácido hialurônico associado a um biovidro experimental de origem vegetal - Equisetum hyemale (BG-Carb), na regeneração de um defeito ósseo em maxila de camundongos. Nesse estudo preliminar, camundongos C57BL/6 (n = 3 por grupo e tempo experimental) (CEUA #042/2022) tiveram seu primeiro molar superior esquerdo extraído. Em seguida, uma ponta diamantada KGS #2128 (KG Soresen®), acoplada a um motor em baixa rotação (5000 rpm) foi utilizada para a realização de um defeito com a remoção do septo alveolar. Parte dos animais tiveram os defeitos preenchidos exclusivamente por HyStem®-HP (hidrogel à base de ácido hialurônico) (2 µL), enquanto a outra parte recebeu BG-Carb (1 µg) disperso em HyStem®-HP (2 µL). Após a eutanásia, as amostram foram processadas para análise histológica de rotina para histomorfometria, graduação do processo inflamatório, vascularização e neoformação óssea após 7 e 21 dias pós-cirúrgicos. Os resultados foram analisados considerando o nível de significância de 5% (p < 0,05). Aos 7 dias, o grupo que recebeu a associação BG-Carb e HyStem®-HP apresentou maiores valores numéricos de neoformação óssea, todavia sem diferença significativa em relação ao uso exclusivo de HyStem®-HP (controle). Aos 21 dias, os grupos HyStem®-HP e BG- Carb associado a HyStem®-HP apresentaram resultados semelhantes tanto na quantificação de tecido ósseo como de conjuntivo. O escore total para graduação para cada material também foi semelhante aos 7 e 21 dias. Apesar disso, comparando-se cada material nos tempos 7 e 21 dias, o grupo HyStem®-HP apresentou aumento significativo de parâmetros qualitativos e quantitativos, demonstrando que a associação HyStem®-HP + BG-Carb apresentou neoformação óssea inicial mais robusta. A quantificação epitelial da região da cirurgia aos 21 dias em ambos os grupos revelou aumento significativo da espessura, continuidade e uniformidade do epitélio nos grupos tratados com o a associação dos biomateriais em relação ao controle. Nas condições experimentais deste estudo, tanto o uso do HyStem®-HP como do HyStem®-HP + BG-Carb podem promover neoformação óssea. No entanto, a associação do hidrogel à base de ácido hialurônico com o BG-Carb parece promover neoformação óssea inicial mais consistente e estimular a proliferação da mucosa adjacente à cirurgia com maior espessura do tecido epitelial.

Bone tissue is a naturally regenerative tissue. However, larger bone defects have a difficult time undergoing this process and require the assistance of grafts or appropriate materials to support new bone formation. Hydrogels are excellent materials to use for this purpose since they can mimic most of the properties of connective tissues. Recently, there has been significant interest in the development of hybrid hydrogels that can be used in various biomedical applications. A variety of particles can be combined with these hydrogels, resulting in better properties. Thus, this study aims to evaluate the influence of a scaffold containing hyaluronic acid associated with an experimental plant-derived bioactive glass - Equisetum hyemale (BG-Carb), on the regeneration of a mouse maxillary bone defect. In this preliminary study, C57BL/6 mice (n = 3 per group and experimental time) (CEUA # 042/2022) had their upper left first molar extracted. Then, a KGS # 2128 diamond bur (KG Soresen®), attached to a low- speed motor (5000 rpm), was used to create a defect with removal of the alveolar septum. Some of the animals had defects filled exclusively with HyStem®-HP (hyaluronic acid-based hydrogel) (2 µL), while the other part received BG-Carb (1 µg) dispersed in HyStem®-HP (2 µL). After euthanasia, the samples were processed for routine histological analysis for histomorphometry, grading of the inflammatory process, vascularization, and new bone formation after 7 and 21 post-surgical days. The results were analyzed considering a significance level of 5% (p < 0.05). At 7 days, the group that received the BG-Carb and HyStem®-HP association showed higher numerical values of new bone formation, but without a significant difference compared to the exclusive use of HyStem®-HP (control). At 21 days, the HyStem®-HP and BG- Carb groups associated with HyStem®-HP showed similar results in both bone and connective tissue quantification. The total score for grading for each material was also similar at 7 and 21 days. However, comparing each material at 7 and 21 days, the HyStem®-HP group showed a significant increase in qualitative and quantitative parameters, demonstrating that the HyStem®-HP + BG-Carb association presented a more robust initial bone formation. The epithelial quantification of the surgery region at 21 days in both groups revealed a significant increase in thickness, continuity, and uniformity of the epithelium in the groups treated with the association of biomaterials compared to the control. Under the experimental conditions of this study, both the use of HyStem®-HP and HyStem®-HP + BG-Carb can promote bone formation. However, the association of the hyaluronic acid-based hydrogel with BG-Carb appears to promote a more consistent initial bone formation and stimulate the proliferation of the mucosa adjacent to the surgery with greater thickness of the epithelial tissue.

Suckermouth catfish bone extract as bone graft raw material for bone-healing promotes bone growth in bone loss / Extrato de osso de bagre como material de reparo promove o crescimento ósseo em perda óssea

Objective: This study aimed to evaluate the properties of suckermouth catfish bone extract, which allows it to be adopted as a raw material for bone graft following its graft in an artificial defect of a rat model. Material and Methods: Hydroxyapatite (HA) from suckermouth catfish bone extract was characterized using Fourier-transform infrared spectroscopy (FTIR), and its toxicity was evaluated by Brine Shrimp Lethality Test (BSLT). This material was grafted on artificial defects in rats' femoral bones, which were observed immunologically by Enzyme-linked immunosorbent assay (ELISA) after one week and four weeks, and radiographically in the second week, and histologically in the second and fourth weeks. Results: FTIR shows that this material consists of phosphate, hydroxyl, and carbonate groups, while the BSLT results show that this material is not toxic. Observations by ELISA showed an increase in the expression of Tumor necrosis factor alpha (TNF-α) in defects with HA in the fourth week. Radiographically the defect did not show closure in the second week. In contrast, histological analysis showed a better bone healing process in the defect, which was applied with the HA of the suckermouth catfish bone. Conclusion: The HA extracted from the suckermouth catfish bone has beneficial properties as an alternative to bone graft raw material and, more investigated needed to support this biomaterial to be used in the treatment of bone loss (AU)

Objetivo: Avaliar as propriedades do extrato de osso de bagre, que permitem sua adoção como material bruto para enxerto ósseo, em um defeito ósseo artificial em ratos. Material e Métodos: A hidroxiapatita (HA) do extrato de osso de bagre foi caracterizada usando espectroscopia infravermelha por transformada de Fourier (FTIR), e sua toxicidade foi avaliada pelo Teste de Letalidade do Camarão de Sal (BSLT). Esse material foi enxertado em defeitos artificiais nos ossos femorais de ratos. Análise imunológica por meio do ensaio imunoenzimático (ELISA) foi realizada uma e quatro semanas após a colocação dos enxertos. Análises radiográficas foram feitas na segunda semana e histológica na segunda e quarta semanas. Resultados: A FTIR mostrou que esse material é composto por grupos de fosfato, hidroxila e carbonato, enquanto os resultados do BSLT mostraram que esse material não é tóxico. As observações pelo ELISA mostraram um aumento na expressão do fator de necrose tumoral alfa (TNF-α) nos defeitos com HA na quarta semana. Radiograficamente, o defeito não apresentou fechamento na segunda semana. Em contraste, a análise histológica mostrou um melhor processo de cicatrização óssea no defeito que foi aplicado com a HA do osso de bagre. Conclusão: A HA extraída do osso de bagre possui propriedades benéficas como alternativa ao material bruto para enxerto ósseo, sendo necessárias mais investigações para apoiar esse biomaterial a ser usado no tratamento da perda óssea.(AU)

Pro-angiogenic photo-crosslinked silk fibroin hydrogel: a potential candidate for repairing alveolar bone defects

Abstract Objective: This study aimed to develop a pro-angiogenic hydrogel with in situ gelation ability for alveolar bone defects repair. Methodology: Silk fibroin was chemically modified by Glycidyl Methacrylate (GMA), which was evaluated by proton nuclear magnetic resonance (1H-NMR). Then, the photo-crosslinking ability of the modified silk fibroin was assessed. Scratch and transwell-based migration assays were conducted to investigate the effect of the photo-crosslinked silk fibroin hydrogel on the migration of human umbilical vein endothelial cells (HUVECs). In vitro angiogenesis was conducted to examine whether the photo-crosslinked silk fibroin hydrogel would affect the tube formation ability of HUVECs. Finally, subcutaneous implantation experiments were conducted to further examine the pro-angiogenic ability of the photo-crosslinked silk fibroin hydrogel, in which the CD31 and α-smooth muscle actin (α-SMA) were stained to assess neovascularization. The tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) were also stained to evaluate inflammatory responses after implantation. Results: GMA successfully modified the silk fibroin, which we verified by our 1H-NMR and in vitro photo-crosslinking experiment. Scratch and transwell-based migration assays proved that the photo-crosslinked silk fibroin hydrogel promoted HUVEC migration. The hydrogel also enhanced the tube formation of HUVECs in similar rates to Matrigel®. After subcutaneous implantation in rats for one week, the hydrogel enhanced neovascularization without triggering inflammatory responses. Conclusion: This study found that photo-crosslinked silk fibroin hydrogel showed pro-angiogenic and inflammation inhibitory abilities. Its photo-crosslinking ability makes it suitable for matching irregular alveolar bone defects. Thus, the photo-crosslinkable silk fibroin-derived hydrogel is a potential candidate for constructing scaffolds for alveolar bone regeneration.

Lesión de Bony Bankart: conceptos fundamentales para su comprensión y tratamiento / Bony Bankart lesions: fundamental concepts to understand and treat them

Las lesiones óseas en el borde anterior del anillo glenoideo secundarias a un episodio de inestabilidad anterior del hombro cada vez son más reportadas. Conocidas como lesión de Bony Bankart, su presencia genera una pérdida de la estabilidad estática glenohumeral que provoca un aumento del riesgo de un nuevo evento de luxación. Por ende, resulta fundamental que los cirujanos ortopédicos comprendan y diagnostiquen estas lesiones de forma correcta y oportuna para evaluar la necesidad de restaurar la superficie articular glenoidea. El objetivo de esta revisión narrativa es otorgar los conceptos más importantes de la lesión ósea de Bankart para comprender y enfrentar de forma adecuada esta lesión.

Bony lesions of the anterior glenoid rim secondary to an episode of anterior instability of the shoulder are increasingly being reported. Known as a bony Bankart lesion, its presence generates a loss of static glenohumeral stability that causes an increased risk of a new dislocation event. Therefore, it is essential that orthopedic surgeons correctly and accurately diagnose these injuries to assess the need to restore the glenoid articular surface. The purpose of the present narrative review is to provide the essential concepts of the bony Bankart lesion to properly understand and deal with this type of injury.

Comparative evaluation of two collagen-based biomaterials with different compositions used for bone graft: An experimental animal study.

A large number of materials with different compositions and shapes have been proposed and studied for the purpose of bone tissue regeneration. Collagen-based materials have shown promising results for this application, with improved physicochemical properties. The aim of the present in vivo animal study was to evaluate and compare two commercially available collagen-based biomaterials for bone regeneration, with these being implanted in circumferential bone defects created in the calvarium of rabbits. Twenty rabbits received bilateral parietal osteotomies, performed with the aid of a 6.5 mm diameter trephine. Two groups were created: the BC group, where the defect was filled with a scaffold composed of 90% bovine bone particles and 10% porcine collagen, and the EG group, where the defect was filled with a scaffold composed of 75% hydroxyapatite particles of bovine origin and 25% bovine collagen. Ten animals were sacrificed at 30 days and another 10 at 45 days after implantation, and the samples were processed and histologically analyzed. In the evaluations of the samples at 30 days, no important differences were found in the results. However, in the samples at 45 days after surgery, the EG group showed better results than the BC group samples, mainly in terms of the amount of bone matrix formation (P < 0.0001) and the volume in area measured in each sample, where the EG group had a value 65% higher than that in the BC group samples. Based on the results obtained, we conclude that the amount of collagen and the particle characteristics present in the composition of the scaffolds can directly influence the amount of neoformation and/or bone regeneration.

Dexamethasone-Loaded Ureasil Hydrophobic Membrane for Bone Guided Regeneration.

Physical barrier membranes have been used to release active substances to treat critical bone defects; however, hydrophilic membranes do not present a prolonged release capacity. In this sense, hydrophobic membranes have been tested. Thus, this study aimed to develop hydrophobic membranes based on mixtures of ureasil-polyether-type materials containing incorporated dexamethasone (DMA) for the application in guided bone regeneration. The physicochemical characterization and biological assays were carried out using small-angle X-ray scattering (SAXS), an in vitro DMA release study, atomic force microscopy (AFM), a hemolysis test, and in vivo bone formation. The swelling degree, SAXS, and release results revealed that the u-PPO400/2000 membrane in the proportion of 70:30 showed swelling (4.69% ± 0.22) similar to the proportions 90:10 and 80:20, and lower than the proportion 60:40 (6.38% ± 0.49); however, an equal release percentage after 134 h was observed between the proportions 70:30 and 60:40. All u-PPO materials presented hemocompatibility (hemolysis ≤2.8%). AFM results showed that the treatments with or without DMA did not present significant differences, revealing a flat/smooth surface, with no pores and/or crystalline precipitates. Finally, in vivo results revealed that for both the commercial hydrophilic membrane and u-PPO400/2000 (70:30) after 60 days, the bone formation volume was 21%. In conclusion, hybrid membranes present unique characteristics for treating critical bone defects, considering the delayed and prolonged release results associated with the physical barrier capacity.

Repair of Critical Size Bone Defects Using Synthetic Hydroxyapatite or Xenograft with or without the Bone Marrow Mononuclear Fraction: A Histomorphometric and Immunohistochemical Study in Rat Calvaria.

Bone defects are a challenging clinical situation, and the development of hydroxyapatite-based biomaterials is a prolific research field that, in addition, can be joined by stem cells and growth factors in order to deal with the problem. This study compares the use of synthetic hydroxyapatite and xenograft, used pure or enriched with bone marrow mononuclear fraction for the regeneration of critical size bone defects in rat calvaria through histomorphometric (Masson's staining) and immunohistochemical (anti-VEGF, anti-osteopontin) analysis. Forty young adult male rats were divided into five groups (n = 8). Animals were submitted to critical size bone defects (Ø = 8 mm) in the temporoparietal region. In the control group, there was no biomaterial placement in the critical bone defects; in group 1, it was filled with synthetic hydroxyapatite; in group 2, it was filled with xenograft; in group 3, it was filled with synthetic hydroxyapatite, enriched with bone marrow mononuclear fraction (BMMF), and in group 4 it was filled with xenograft, enriched with BMMF. After eight weeks, all groups were euthanized, and histological section images were captured and analyzed. Data analysis showed that in groups 1, 2, 3 and 4 (received biomaterials and biomaterials plus BMMF), a significant enhancement in new bone matrix formation was observed in relation to the control group. However, BMMF-enriched groups did not differ from hydroxyapatite-based biomaterials-only groups. Therefore, in this experimental model, BMMF did not enhance hydroxyapatite-based biomaterials' potential to induce bone matrix and related mediators.

Biological behavior of magnesium-substituted hydroxyapatite during bone repair / Comportamento biológico de hidroxiapatita substituída com magnésio durante o reparo ósseo

The aim of this study was to analyze the biological behavior and osteogenic potential of magnesium (Mg) substituted hydroxyapatite (HA) microspheres, implanted in a critical bone defect, considering that this ion is of great clinical interest, since it is closely associated with homeostasis and bone mineralization. For the purpose of this study, 30 rats were used to compose three experimental groups: GI - bone defect filled with HA microspheres; GII - bone defect filled with HA microspheres replaced with Mg; GIII - empty bone defect; evaluated at biological points of 15 and 45 days. The histological results, at 15 days, showed, in all the groups, a discrete chronic inflammatory infiltrate; biomaterials intact and surrounded by connective tissue; and bone neoformation restricted to the borders. At 45 days, in the GI and GII groups, an inflammatory response of discrete granulomatous chronic type was observed, and in the GIII there was a scarce presence of mononuclear inflammatory cells; in GI and GII, the microspheres were seen to be either intact or fragmented, surrounded by fibrous connective tissue rich in blood vessels; and discrete bone neoformation near the edges and surrounding some microspheres. In GIII, the mineralization was limited to the borders and the remaining area was filled by fibrous connective tissue. It was concluded that the biomaterials were biocompatible and osteoconductive, and the percentage of Mg used as replacement ion in the HA did not favor a greater bone neoformation in relation to the HA without the metal.(AU)

O objetivo deste estudo foi analisar o comportamento biológico de microesferas de hidroxiapatita (HA) substituída com magnésio (Mg) durante o reparo de defeito ósseo crítico, tendo em vista que este íon é de grande interesse clínico, pois está intimamente associado à homeostasia e à mineralização óssea. Para tanto, utilizou-se 30 ratos para compor três grupos experimentais: GI - defeito ósseo preenchido com microesferas de HA; GII - defeito ósseo preenchido com microesferas de HA substituída com Mg; GIII (controle) - defeito ósseo vazio; avaliados nos pontos biológicos de 15 e 45 dias. Os resultados histológicos evidenciaram, aos 15 dias, discreto infiltrado inflamatório crônico e neoformação óssea restrita às bordas, em todos os grupos. Nos grupos GI e GII, os biomateriais mantiveram-se íntegros e circundados por tecido conjuntivo frouxo. Aos 45 dias, notou-se resposta inflamatória do tipo crônica granulomatosa discreta nos grupos GI e GII, e no GIII presença escassa de células inflamatórias mononucleares. As microesferas implantadas no GI e GII mantiveram-se, em sua maioria, íntegras e envolvidas por tecido conjuntivo fibroso. Notou-se discreta neoformação óssea próxima às bordas e circunjacente a algumas microesferas. No GIII, a mineralização limitou-se às bordas e a área remanescente foi preenchida por tecido conjuntivo fibroso. Conclui-se que os biomateriais foram biocompatíveis, bioativos, osteocondutores e apresentaram biodegradação lenta, indicando seu grande potencial para em aplicações clínica como biomaterial de preenchimento.(AU)

Biological behavior of magnesium-substituted hydroxyapatite during bone repair / Comportamento biológico de hidroxiapatita substituída com magnésio durante o reparo ósseo

Abstract The aim of this study was to analyze the biological behavior and osteogenic potential of magnesium (Mg) substituted hydroxyapatite (HA) microspheres, implanted in a critical bone defect, considering that this ion is of great clinical interest, since it is closely associated with homeostasis and bone mineralization. For the purpose of this study, 30 rats were used to compose three experimental groups: GI - bone defect filled with HA microspheres; GII - bone defect filled with HA microspheres replaced with Mg; GIII - empty bone defect; evaluated at biological points of 15 and 45 days. The histological results, at 15 days, showed, in all the groups, a discrete chronic inflammatory infiltrate; biomaterials intact and surrounded by connective tissue; and bone neoformation restricted to the borders. At 45 days, in the GI and GII groups, an inflammatory response of discrete granulomatous chronic type was observed, and in the GIII there was a scarce presence of mononuclear inflammatory cells; in GI and GII, the microspheres were seen to be either intact or fragmented, surrounded by fibrous connective tissue rich in blood vessels; and discrete bone neoformation near the edges and surrounding some microspheres. In GIII, the mineralization was limited to the borders and the remaining area was filled by fibrous connective tissue. It was concluded that the biomaterials were biocompatible and osteoconductive, and the percentage of Mg used as replacement ion in the HA did not favor a greater bone neoformation in relation to the HA without the metal.

Resumo O objetivo deste estudo foi analisar o comportamento biológico de microesferas de hidroxiapatita (HA) substituída com magnésio (Mg) durante o reparo de defeito ósseo crítico, tendo em vista que este íon é de grande interesse clínico, pois está intimamente associado à homeostasia e à mineralização óssea. Para tanto, utilizou-se 30 ratos para compor três grupos experimentais: GI - defeito ósseo preenchido com microesferas de HA; GII - defeito ósseo preenchido com microesferas de HA substituída com Mg; GIII (controle) - defeito ósseo vazio; avaliados nos pontos biológicos de 15 e 45 dias. Os resultados histológicos evidenciaram, aos 15 dias, discreto infiltrado inflamatório crônico e neoformação óssea restrita às bordas, em todos os grupos. Nos grupos GI e GII, os biomateriais mantiveram-se íntegros e circundados por tecido conjuntivo frouxo. Aos 45 dias, notou-se resposta inflamatória do tipo crônica granulomatosa discreta nos grupos GI e GII, e no GIII presença escassa de células inflamatórias mononucleares. As microesferas implantadas no GI e GII mantiveram-se, em sua maioria, íntegras e envolvidas por tecido conjuntivo fibroso. Notou-se discreta neoformação óssea próxima às bordas e circunjacente a algumas microesferas. No GIII, a mineralização limitou-se às bordas e a área remanescente foi preenchida por tecido conjuntivo fibroso. Conclui-se que os biomateriais foram biocompatíveis, bioativos, osteocondutores e apresentaram biodegradação lenta, indicando seu grande potencial para em aplicações clínica como biomaterial de preenchimento.

One-Stage Hip Revision Arthroplasty Using Megaprosthesis in Severe Bone Loss of The Proximal Femur Due to Radiological Diffuse Osteomyelitis.

Managing substantial proximal and/or distal femoral bone defects is one of the biggest challenges in chronic hip periprosthetic joint infection. Most authors use two-stage arthroplasty with a temporary antibiotic-loaded cement spacer for the management of these patients. In this study, we show our experience with one-stage exchange arthroplasty in managing severe bone defects due to radiological-extensive proximal femoral osteomyelitis. Two patients were included in the study. They showed radiological-extensive proximal femoral osteomyelitis, and they were treated with one-stage exchange arthroplasty using megaprosthesis. Diffuse osteomyelitis was confirmed in both cases; in one case, the histology was compatible with osteomyelitis, and the other case had a positive culture identified in a bone sample. At a minimum of a four-year follow-up, the patients did not reveal any clinical, radiological or laboratory signs of infection. In conclusion, one-stage exchange arthroplasty and megaprosthesis is an option for the treatment of chronic hip periprosthetic joint infection associated with radiological-diffuse proximal femoral osteomyelitis.

The use of photobiomodulation therapy or LED and mineral trioxide aggregate improves the repair of complete tibial fractures treated with wire osteosynthesis in rodents.

The repair of large bone defects is lengthy and complex. Both biomaterials and phototherapy have been used to improve bone repair. We aimed to describe histologically the repair of tibial fractures treated by wiring (W), irradiated or not, with laser (λ780 nm, 70 mW, CW, spot area of 0.5 cm2, 20.4 J/cm2 (4 × 5.1 J/cm2, Twin Flex Evolution®, MM Optics, Sao Carlos, SP, Brazil) per session, 300 s, 142.8 J/cm2 per treatment) or LED (λ850 ± 10 nm, 150 mW, spot area of 0.5 cm2, 20.4 J/cm2 per session, 64 s, 142.8 J/cm2 per treatment, Fisioled®, MM Optics, Sao Carlos, Sao Paulo, Brazil) and associated or not to the use of mineral trioxide aggregate (MTA, Angelus®, Londrina, PR, Brazil). Inflammation was discrete on groups W and W + LEDPT and absent on the others. Phototherapy protocols started immediately before suturing and repeated at every other day for 15 days. Collagen deposition intense on groups W + LEDPT, W + BIO-MTA + LaserPT and W + BIO-MTA + LEDPT and discrete or moderate on the other groups. Reabsorption was discrete on groups W and W + LEDPT and absent on the other groups. Neoformation varied greatly between groups. Most groups were partial and moderately filed with new-formed bone (W, W + LaserPT, W + LEDPT, W + BIO-MTA + LEDPT). On groups W + BIO-MTA and W + BIO-MTA + LaserPT bone, neoformation was intense and complete. Our results are indicative that the association of MTA and PBMT (λ = 780 nm) improves the repair of complete tibial fracture treated with wire osteosynthesis in a rodent model more efficiently than LED (λ = 850 ± 10 nm).