RESUMO
Bone is a dynamic tissue that can always rebuild itself by modeling and remodeling to maintain functionality. This tissue is responsible for several vital functions in the body, such as providing structural support for soft tissues and the body, being the central region of hematopoiesis in human adults, and contributing to mineral homeostasis. Besides, it has an innate ability of auto-regeneration when damaged. All of these processes involve several molecular cues related to biochemical and mechanical stimulus. However, when the lesion is complicated or too big, it is necessary to intervene surgically, which may not effectively solve the problem. Bone tissue engineering seeks to provide resources to resolve these clinical issues and has been advancing in recent years, presenting promising devices for bone tissue repair. The understanding of some important biofactors and bone stem-cells influence might be crucial for an effective regenerative medicine, since bone is one of the most transplanted tissues. So, the purpose of this article is to provide an overview of the bone tissue, including the role of stem cells and some of the bioactive molecules associated with these processes. Finally, we will suggest future directions for bone tissue engineering area that might be helpful in order to produce biomimetic bone substitutes that become a real alternative to translational medicine.
Assuntos
Materiais Biocompatíveis , Osso e Ossos/citologia , Osso e Ossos/fisiologia , Fraturas Ósseas/fisiopatologia , Engenharia Tecidual/métodos , Animais , Remodelação Óssea/fisiologia , Humanos , Células-TroncoRESUMO
Abstract Pelvic fractures occur in up to 25% of all severely injured trauma patients and its mortality is markedly high despite advances in resuscitation and modernization of surgical techniques due to its inherent blood loss and associated extra-pelvic injuries. Pelvic ring volume increases significantly from fractures and/or ligament disruptions which precludes its inherent ability to self-tamponade resulting in accumulation of hemorrhage in the retroperitoneal space which inevitably leads to hemodynamic instability and the lethal diamond. Pelvic hemorrhage is mainly venous (80%) from the pre-sacral/pre-peritoneal plexus and the remaining 20% is of arterial origin (branches of the internal iliac artery). This reality can be altered via a sequential management approach that is tailored to the specific reality of the treating facility which involves a collaborative effort between orthopedic, trauma and intensive care surgeons. We propose two different management algorithms that specifically address the availability of qualified staff and existing infrastructure: one for the fully equipped trauma center and another for the very common limited resource center.
Resumen Las fracturas de pelvis ocurren en más del 25% de los pacientes con trauma severo y su mortalidad es alta, a pesar de los avances en la resucitación hemodinámica y las técnicas quirúrgicas. Esta mortalidad se explica por la hemorragia inherente y las lesiones extra pélvicas asociadas, las fracturas o las disrupciones ligamentarias de la pelvis aumentan el volumen del espacio pélvico, y conlleva a que la hemorragia pélvica se acumule en el espacio retroperitoneal. En poco tiempo, esto conduce a la inestabilidad hemodinámica y el rombo de la muerte. La hemorragia pélvica es un 80% venosa proveniente de los plexos pre-sacro / pre-peritoneal. El restante 20% es arterial por sangrado de las ramas de la arteria iliaca interna. Esta realidad podría ser cambiada a través de un manejo secuencial enfocado según la disposición de recursos del centro de atención y de un trabajo colaborativo entre ortopedistas, cirujanos de trauma e intensivistas. Este articulo propone dos algoritmos de manejo que están enfocados según la disponibilidad de un equipo calificado e infraestructura existente: uno para un centro de trauma totalmente equipado, y el otro para un centro con recursos limitados.
Assuntos
Humanos , Ossos Pélvicos/cirurgia , Ossos Pélvicos/lesões , Algoritmos , Fraturas Ósseas/cirurgia , Fraturas Ósseas/fisiopatologia , HemodinâmicaRESUMO
Polycaprolactone (PCL) is a biocompatible, biodegradable synthetic polymer which in combination with nanohydroxyapatite (nHAp) can give rise to a low cost, nontoxic bioactive product with excellent mechanical properties and slow degradation. Here we produced, characterized and evaluated in vivo the bone formation of PCL/nHAp scaffolds produced by the rotary jet spinning technique. The scaffolds produced were firstly soaked into simulated body fluid for 21 days to also obtain nHAp onto PCL/nHAp scaffolds. Afterwards, the scaffolds were characterized by scanning electron microscopy (SEM), energy dispersive spectroscopy and Raman spectroscopy. For in vivo experiments, 20 male Wistar rats were used and randomly divided in 4 experimental groups (n = 5). A critical defect of 3 mm in diameter was made in the tibia of the animals, which were filled with G1 control (clot); G2-PCL scaffold; G3-PCL/nHAp (5%) scaffold; G4-PCL/nHAp (20%) scaffold. All animals were euthanized 60 days after surgery, and the bone repair in the right tibiae were evaluated by radiographic analysis, histological analysis and histomorphometric analysis. While in the left tibias, the areas of bone repair were submitted to the flexural strength test. Radiographic and histomorphometric analyses no showed statistical difference in new bone formation between the groups, but in the three-point flexural tests, the PCL/nHAp (20%) scaffold positively influenced the flexural mode of the neoformed bone. These findings indicate that PCL/nHAp (20%) scaffold improve biomechanical properties of neoformed bone and could be used for bone medicine regenerative.
Assuntos
Líquidos Corporais/química , Durapatita/química , Resistência à Flexão , Osteogênese , Poliésteres/química , Alicerces Teciduais/química , Animais , Fenômenos Biomecânicos/efeitos dos fármacos , Líquidos Corporais/fisiologia , Regeneração Óssea/efeitos dos fármacos , Substitutos Ósseos/síntese química , Substitutos Ósseos/química , Substitutos Ósseos/farmacologia , Materiais Revestidos Biocompatíveis/síntese química , Materiais Revestidos Biocompatíveis/química , Materiais Revestidos Biocompatíveis/farmacologia , Durapatita/farmacologia , Resistência à Flexão/efeitos dos fármacos , Resistência à Flexão/fisiologia , Fraturas Ósseas/fisiopatologia , Fraturas Ósseas/terapia , Regeneração Tecidual Guiada/instrumentação , Regeneração Tecidual Guiada/métodos , Masculino , Teste de Materiais , Nanoestruturas/química , Osteogênese/efeitos dos fármacos , Poliésteres/farmacologia , Polímeros/síntese química , Polímeros/química , Polímeros/farmacologia , Ratos , Ratos Wistar , Estresse Mecânico , Tíbia/patologia , Engenharia Tecidual/instrumentação , Engenharia Tecidual/métodosRESUMO
OBJECTIVES: Understand the experience of older adults after hip fracture surgery considering barriers and facilitators related to sedentary behavior. METHODS: A qualitative study using a semi-structured interview with three men and eight women aged 60 years or older after hip fracture surgery. RESULTS: Five barriers emerged: physical complaints, lack of accessibility, fear of falling, demotivation and negative social representation of old age, and two facilitators: overcoming dependency and having a caregiver. CONCLUSION: Our results highlight that physical complaints commonly addressed by physical therapists on their interventions are not the only impediments to reduce sedentary behavior. Important individual and social barriers should not be neglected when physical therapists conduct interventions to reduce sedentary behavior to maximize functional recovery in older adults after hip fracture surgery. Future clinical trials are required to investigate the effectiveness of more comprehensive interventions to reduce sedentary behavior in this population.
Assuntos
Fraturas Ósseas/fisiopatologia , Comportamento Sedentário , Acidentes por Quedas , Idoso , Medo , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Pesquisa QualitativaRESUMO
Several therapeutic strategies have been proposed to optimize the conventional treatment of fractures. Photobiomodulation (PBM) appears to help reduce pain and control inflammation, and it also accelerates bone repair. This systematic review aimed to evaluate the effectiveness and safety of PBM with low-level laser therapy (LLLT) in the bone fracture healing process. We included randomized controlled trials (RCTs) comparing the effects of PBM with those of any other intervention in adults with lower or upper limb bone fractures. The primary outcomes investigated were pain reduction, radiographic healing, and adverse events. The searches were conducted in October 2018. Two RCTs were included that compared PBM to the placebo. A meta-analysis showed significant difference in favor of PBM for pain reduction (MD 1.19, 95% CI [0.61 to 1.77], 106 participants, two RCTs), but this difference was not clinically significant. One RCT (50 participants) showed a clinical and statistical improvement in physical function (MD - 14.60, 95% CI [- 21.39 to - 7.81]) and no difference in radiographic healing, regarding absence of fracture line (RR 1.00, 95% CI [0.93 to 1.08]) and visible bone callus (RR 0.33, 95% CI [0.01 to 7.81]). The certainty of evidence was classified as low to very low. Based on the evidence of low to very low certainty, PBM seems to be associated with the improvement of pain and function. Therefore, new RCTs are required that meet the recommendations of CONSORT to prove the effectiveness and safety of this intervention and support its recommendation in clinical practice.
Assuntos
Fraturas Ósseas/radioterapia , Terapia com Luz de Baixa Intensidade , Ensaios Clínicos Controlados Aleatórios como Assunto , Consolidação da Fratura/efeitos da radiação , Fraturas Ósseas/fisiopatologia , HumanosRESUMO
Pelvic fractures occur in up to 25% of all severely injured trauma patients and its mortality is markedly high despite advances in resuscitation and modernization of surgical techniques due to its inherent blood loss and associated extra-pelvic injuries. Pelvic ring volume increases significantly from fractures and/or ligament disruptions which precludes its inherent ability to self-tamponade resulting in accumulation of hemorrhage in the retroperitoneal space which inevitably leads to hemodynamic instability and the lethal diamond. Pelvic hemorrhage is mainly venous (80%) from the pre-sacral/pre-peritoneal plexus and the remaining 20% is of arterial origin (branches of the internal iliac artery). This reality can be altered via a sequential management approach that is tailored to the specific reality of the treating facility which involves a collaborative effort between orthopedic, trauma and intensive care surgeons. We propose two different management algorithms that specifically address the availability of qualified staff and existing infrastructure: one for the fully equipped trauma center and another for the very common limited resource center.
Las fracturas de pelvis ocurren en más del 25% de los pacientes con trauma severo y su mortalidad es alta, a pesar de los avances en la resucitación hemodinámica y las técnicas quirúrgicas. Esta mortalidad se explica por la hemorragia inherente y las lesiones extra pélvicas asociadas, las fracturas o las disrupciones ligamentarias de la pelvis aumentan el volumen del espacio pélvico, y conlleva a que la hemorragia pélvica se acumule en el espacio retroperitoneal. En poco tiempo, esto conduce a la inestabilidad hemodinámica y el rombo de la muerte. La hemorragia pélvica es un 80% venosa proveniente de los plexos pre-sacro / pre-peritoneal. El restante 20% es arterial por sangrado de las ramas de la arteria iliaca interna. Esta realidad podría ser cambiada a través de un manejo secuencial enfocado según la disposición de recursos del centro de atención y de un trabajo colaborativo entre ortopedistas, cirujanos de trauma e intensivistas. Este articulo propone dos algoritmos de manejo que están enfocados según la disponibilidad de un equipo calificado e infraestructura existente: uno para un centro de trauma totalmente equipado, y el otro para un centro con recursos limitados.
Assuntos
Algoritmos , Fraturas Ósseas/fisiopatologia , Fraturas Ósseas/cirurgia , Hemodinâmica , Ossos Pélvicos/lesões , Ossos Pélvicos/cirurgia , HumanosRESUMO
BACKGROUND: Photobiomodulation therapy (PBMT) using low-level laser influences the release of several growth factors involved in the formation of epithelial cells, fibroblasts, collagen and vascular proliferation, besides accelerating the synthesis of bone matrix due to the increased vascularization and lower inflammatory response, with significant increase of osteocytes in the irradiated bone. Considering its properties, beneficial effects and clinical relevance, the aim of this review was to analyze the scientific literature regarding the use of PBMT in the process of bone defect repair. METHODS: Electronic search was carried out in PubMed/MEDLINEâ and Web of Science databases with combination of the descriptors low-level laser therapy AND bone repair, considering the period of publication until the year 2018. RESULTS: The literature search identified 254 references in PubMed/MEDLINE and 204 in Web of Science, of which 33 and 4 were selected, respectively, in accordance with the eligibility requirements. The analysis of researches showed articles using PBMT in several places of experimentation in the subjects, different types of associated biomaterials, stimulatory effects on cell proliferation, besides variations in the parameters of use of laser therapy, mainly in relation to the wavelength and density of energy. Only four articles reported that the laser did not improve the osteogenic properties of a biomaterial. CONCLUSIONS: Many studies have shown that PBMT has positive photobiostimulatory effects on bone regeneration, accelerating its process regardless of parameters and the use of biomaterials. However, standardization of its use is still imperfect and should be better studied to allow correct application concerning the utilization protocols.
Assuntos
Regeneração Óssea/efeitos da radiação , Proliferação de Células/efeitos da radiação , Consolidação da Fratura/efeitos da radiação , Fraturas Ósseas/radioterapia , Terapia com Luz de Baixa Intensidade , Osteogênese/efeitos da radiação , Regeneração Óssea/fisiologia , Colágeno/metabolismo , Fibroblastos/metabolismo , Consolidação da Fratura/fisiologia , Fraturas Ósseas/fisiopatologia , Humanos , Terapia com Luz de Baixa Intensidade/métodos , Osteogênese/fisiologiaRESUMO
OBJECTIVE: To describe the association between fractures sustained at different stages of growth and bone measures in early adulthood. STUDY DESIGN: Participants (n = 201) in southern Tasmania were at birth at a higher risk of sudden infant death syndrome; they were followed to age 25. Outcomes were areal bone mineral density at the spine, hip, and total body (by dual-energy x-ray absorptiometry) and trabecular and cortical bone measures at the radius and tibia (by high-resolution peripheral quantitative computed tomography). Fractures were self-reported and confirmed by radiographs at 8, 16, and 25 years of age. Multivariable linear regression was used to analyze the association of the occurrence of prepubertal (<9 years of age), pubertal (9-16 years of age), and postpubertal (17-25 years of age) fractures with all bone measures. RESULTS: Over 25 years, 99 participants had at least 1 fracture. For high-resolution peripheral quantitative computed tomography measures at age 25, prepubertal fractures were negatively associated with cortical and trabecular volumetric bone mineral density and most microarchitecture measures at both the tibia and radius. Prepubertal fractures had a significant association with smaller increase of areal bone mineral density from age 8 to 16 years and at 25 years of age compared with participants with no fractures. Pubertal fractures had no association with any bone measures and postpubertal fractures were only associated with a lower trabecular number at the tibia. CONCLUSIONS: Prepubertal fractures are negatively associated with areal bone mineral density increases during growth and high-resolution peripheral quantitative computed tomography bone measures in young adulthood. There is little evidence that fractures occurring from age 8 years onward with bone measures in young adulthood, implying that prepubertal fractures may be associated with bone deficits later in life.
Assuntos
Densidade Óssea , Fraturas Ósseas/diagnóstico por imagem , Fraturas Ósseas/fisiopatologia , Absorciometria de Fóton , Adolescente , Adulto , Fatores Etários , Criança , Feminino , Humanos , Masculino , Adulto JovemRESUMO
OBJECTIVE: To evaluate the epidemiological data and available treatments for fractures secondary to radiotherapy treatment. METHODS: Identification of publications on pathological skeletal fractures previously exposed to ionizing radiation. RESULTS: The incidence of fractures after irradiation varies from 1.2% to 25% with a consolidation rate of 33% to 75%, being more frequent in the ribs, pelvis, and femur. The time elapsed between irradiation and fracture occurs years after radiotherapy. Risk factors include age above 50 years, female gender, extensive periosteal detachment, circumferential irradiation, tumor size, and anterior thigh location. The etiology is still uncertain, but cellular disappearance, reduction of bone turnover and activity were observed hematopoietic as possible causes of failure of consolidation. CONCLUSION: There is no consensus in the literature on the factors related to the development of fractures, with radiation dose, previous tumor size and periosteal detachment being suggested as potential factors.
Assuntos
Fraturas Ósseas/etiologia , Lesões por Radiação/complicações , Radioterapia/efeitos adversos , Fraturas Ósseas/fisiopatologia , Humanos , Fatores de RiscoRESUMO
SUMMARY OBJECTIVE: To evaluate the epidemiological data and available treatments for fractures secondary to radiotherapy treatment. METHODS: Identification of publications on pathological skeletal fractures previously exposed to ionizing radiation. RESULTS: The incidence of fractures after irradiation varies from 1.2% to 25% with a consolidation rate of 33% to 75%, being more frequent in the ribs, pelvis, and femur. The time elapsed between irradiation and fracture occurs years after radiotherapy. Risk factors include age above 50 years, female gender, extensive periosteal detachment, circumferential irradiation, tumor size, and anterior thigh location. The etiology is still uncertain, but cellular disappearance, reduction of bone turnover and activity were observed hematopoietic as possible causes of failure of consolidation. CONCLUSION: There is no consensus in the literature on the factors related to the development of fractures, with radiation dose, previous tumor size and periosteal detachment being suggested as potential factors.
RESUMO OBJETIVO: Avaliar dados epidemiológicos e tratamentos disponíveis para fraturas secundárias ao tratamento radioterápico. MÉTODOS: Identificação de publicações sobre as fraturas patológicas ocorridas em esqueleto previamente exposto à radiação ionizante. RESULTADOS: A incidência de fraturas após irradiação varia de 1,2% a 25% com taxa de consolidação de 33% a 75%, sendo mais frequente em costelas, pelve e fêmur. O tempo decorrido entre a irradiação e a fratura ocorre anos após a radioterapia. Os fatores de risco incluem idade acima de 50 anos, sexo feminino, descolamento periosteal extenso, irradiação circunferencial, tamanho do tumor e localização anterior na coxa. A etiologia ainda é incerta, mas foram observados desaparecimento celular, redução do turnover ósseo e da atividade hematopoiética como possíveis causas da falha de consolidação. CONCLUSÃO: Não há consenso na literatura avaliada sobre os fatores relacionados ao desenvolvimento de fraturas, sendo a dose de radiação, o tamanho prévio do tumor e o descolamento periosteal sugeridos como fatores potenciais.