Neutrophil Extracellular Trap-related Biomarkers Are Increased in the Synovial Fluid of Patients With Periprosthetic Joint Infections.

BACKGROUND: The diagnosis of periprosthetic joint infection (PJI) is a major challenge in clinical practice. The role of neutrophils in fighting infection has been increasingly understood, and one mechanism of action of these cells is neutrophil extracellular traps. However, little is known about this process in PJI. QUESTIONS/PURPOSES: (1) Are the biomarkers of neutrophil extracellular trap formation (citrullinated histone H3 [H3Cit], cell-free DNA [cf-DNA], and myeloperoxidase [MPO]) increased in the synovial fluid of patients with PJI? (2) What is the diagnostic accuracy of biomarkers of neutrophil extracellular trap formation for PJI? METHODS: Between May 2020 and March 2021, 43 patients who underwent revision THA or TKA were enrolled in this study. Eleven patients were excluded and 32 patients were categorized into the PJI group (n = 16) or non-PJI group (n = 16) according to the 2018 Second International Consensus Meeting on Musculoskeletal Infection criteria. There were 15 men and 17 women in this study, with a median (range) age of 70 years (60 to 80 years). Twenty-seven patients had TKA and five had THA. We measured cf-DNA, MPO, and H3Cit in synovial fluid. The sensitivity, specificity, and receiver operating characteristic curve were calculated for each biomarker using the Musculoskeletal Infection Society criteria as the gold standard for diagnosis and considering a clinical surveillance of 2 years for patients in the non-PJI group. RESULTS: Patients with PJI had higher levels of synovial fluid cf-DNA (median [range] 130 ng/µL [18 to 179] versus 2 ng/µL [0 to 6]; p < 0.001), MPO (1436 ng/µL [55 to 3996] versus 0 ng/µL [0 to 393]; p < 0.001), and H3Cit (2115 ng/µL [5 to 2885] versus 3 ng/µL [0 to 87]; p < 0.001) than those in the non-PJI group. In receiver operating characteristic curve analyses, we observed near-perfect performance for all biomarkers evaluated, with an area under the curve of 1 (95% CI 0.9 to 1), 0.98 (95% CI 0.9 to 1), and 0.94 (95% CI 0.8 to 0.99) for cf-DNA, MPO, and H3Cit, respectively. The sensitivity for detecting PJI using synovial fluid was 100% for cf-DNA, 94% for MPO, and 88% for H3Cit. The specificity was 100% for cf-DNA and MPO, and 88% for H3Cit. CONCLUSION: Our results show that neutrophils in the periprosthetic microenvironment release neutrophil extracellular traps as part of the bactericidal arsenal to fight infection. These results allow a better understanding of the cellular and molecular processes that occur in this microenvironment, enabling the design of more assertive strategies for identifying new biomarkers and improving the available ones. Novel studies are needed to define whether and how neutrophil extracellular trap-related biomarkers can be useful for diagnosing PJI. LEVEL OF EVIDENCE: Level II, diagnostic study.

Accuracy of Serological Markers, Synovial Fluid, Microbiological Culture, and Histopathological Examination for Diagnosing Periprosthetic Knee Infection.

Objective This study assessed the sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of serological tests, synovial fluid markers, microbiological tissue culture, and histopathological examination of the periprosthetic membrane in diagnosing periprosthetic knee infection. Methods This study is prospective, and it includes patients undergoing total knee arthroplasty revision surgery from November 2019 to December 2021. The analysis consisted of serological tests (erythrocyte sedimentation rate [ESR], C-reactive protein [CRP], and D-dimer), synovial fluid markers (leukocyte and polymorphonuclear cell counts), periprosthetic tissue culture, and histopathological examination of the periprosthetic membrane of all patients. Results Sixty-two patients had periprosthetic joint infection (PJI) according to the 2018 International Consensus Meeting criteria (infection group), while 22 subjects had no infection. ESR sensitivity and specificity were 83.6% and 45.4%, respectively. CRP sensitivity and specificity were 64.5% and 100%, whereas D-dimer sensitivity and specificity were 78.9% and 25%, respectively. Leukocyte count sensitivity and specificity were 75.6% and 100%, polymorphonuclear cell count sensitivity and specificity were 33% and 100%, respectively. Periprosthetic tissue culture sensitivity and specificity culture were, respectively, 77.4% and 100%. Histopathological examination sensitivity and specificity were 43.7% and 100%, respectively. Conclusions In our study, the total blood cell count in synovial fluid and microbiological cultures of periprosthetic tissues were the most accurate tests for PJI diagnosis. In contrast, polymorphonuclear cell percentage was the least accurate test for PJI diagnosis.

Continuous Vertical Inside-Out Versus Traditional Vertical Inside-Out Meniscal Repair: A Biomechanical Comparison.

Background: Biomechanical assessment of meniscal repairs is essential for evaluating different meniscal suturing methods and techniques. The continuous meniscal suture technique is a newer method of meniscal repair that may have biomechanical differences compared with traditional techniques. Purpose: To evaluate the displacement, stiffness after cyclical loading, and load to failure for a continuous vertical inside-out meniscal suture versus a traditional vertical inside-out meniscal suture in a porcine medial meniscus. Study Design: Controlled laboratory study. Methods: A total of 28 porcine knees were acquired and divided into 2 test groups of 14 medial meniscus each. A 2.0-cm longitudinal red-white zone cut was made in the body of the medial meniscus for each knee. The continuous suture (CS) group received 4 vertical stitches performed with a continuous vertical meniscal suture technique, and the inside-out suture (IO) group received a traditional vertical suture with 4 stitches. Two traction tapes were passed between the sutures and positioned in the biomechanical testing fixture device. Each specimen underwent load-to-failure testing at 5 mm/s, and displacement, system stiffness, and maximum load to failure were compared between the groups. Results: The displacement after the cyclic test was 0.53 ± 0.12 and 0.48 ± 0.07 mm for the CS and IO groups, respectively. There was no significant difference between the groups (P = .2792). The stiffness at the ultimate load testing was 36.3 ± 1.9 and 35.3 ± 2.4 N/mm for groups CS and IO, respectively, with no significant difference between the groups (P = .2557). In the load-to-failure test, the ultimate load was 218.2 ± 63.9 and 238.3 ± 71.3 N in the CS and IO groups, respectively, with no significant group differences (P = .3062). Conclusion: A continuous vertical meniscal suture created a configuration for treating longitudinal meniscal lesions that was beneficial and biomechanically similar to a traditional vertical suture technique. Clinical Relevance: The study findings indicate that use of the continuous vertical inside-out meniscal suture technique is a possible therapeutic option.

Microbiological Profile of Periprosthetic Knee Infections in a Brazilian Unified Health System Hospital Specialized in Highly Complex Orthopedic Surgeries.

Objective We studied the microbiological profile of periprosthetic knee infections treated in a Brazilian tertiary hospital. Methods The study included all patients undergoing revision surgery for total knee arthroplasty (RTKA) between November 2019 and December 2021, with a diagnosis of periprosthetic infection confirmed per the 2018 International Consensus Meeting (ICM) criteria. Results Sixty-two patients had a periprosthetic joint infection (PJI) per the 2018 ICM criteria. Cultures were monomicrobial in 79% and polymicrobial in 21% of cases. The most frequent bacterium in microbiological tissue and synovial fluid cultures was Staphylococcus aureus , observed in 26% of PJI patients. Periprosthetic joint infection with negative cultures occurred in 23% of patients. Conclusion Our results show the following: i) a high prevalence of Staphylococcus as an etiological agent for knee PJI; ii) a high incidence of polymicrobial infections in early infections; iii) the occurrence of PJI with negative cultures in approximately one fourth of the subjects.

Microbiological Profi le of Periprosthetic Knee Infections in a Brazilian Unified Health System Hospital Specialized in Highly Complex Orthopedic Surgeries / Perfil microbiológico das infecções periprotéticas do joelho em um hospital do Sistema Único de Saúde especializado em cirurgias ortopédicas de alta complexidade

Abstract Objective We studied the microbiological profile of periprosthetic knee infections treated in a Brazilian tertiary hospital. Methods The study included all patients undergoing revision surgery for total knee arthroplasty (RTKA) between November 2019 and December 2021, with a diagnosis of periprosthetic infection confirmed per the 2018 International Consensus Meeting (ICM) criteria. Results Sixty-two patients had a periprosthetic joint infection (PJI) per the 2018 ICM criteria. Cultures were monomicrobial in 79% and polymicrobial in 21% of cases. The most frequent bacterium in microbiological tissue and synovial fluid cultures was Staphylococcus aureus, observed in 26% of PJI patients. Periprosthetic joint infection with negative cultures occurred in 23% of patients. Conclusion Our results show the following: i) a high prevalence of Staphylococcus as an etiological agent for knee PJI; ii) a high incidence of polymicrobial infections in early infections; iii) the occurrence of PJI with negative cultures in approximately one fourth of the subjects.

Resumo Objetivo Identificar o perfil microbiológico das infecções periprotéticas do joelho tratadas em um hospital terciário brasileiro. Métodos Todos os pacientes submetidos à cirurgia de revisão de artroplastia total do joelho (RATJ), no período compreendido entre novembro de 2019 e dezembro de 2021, e que tiveram o diagnóstico de infecção periprotética confirmado de acordo com critérios do International Consensus Meeting (ICM) 2018, foram incluídos no estudo. Resultados Sessenta e dois pacientes foram diagnosticados com infecção periprotética (IAP) pelos critérios do International Consensus Meeting 2018. Culturas monomicrobianas foram identificadas em 79% e polimicrobianas em 21% dos casos. A bactéria mais frequentemente identificada nas culturas microbiológicas de tecidos e líquido sinovial foi o Staphylococcus aureus, presente em 26% dos pacientes com infecção periprotética. Infecções periprotéticas com culturas negativas ocorreram em 23% dos pacientes. Conclusão Nossos resultados evidenciam: i) alta prevalência de bactérias do gênero Staphylococcus como causadores da IAP do joelho; ii) a alta incidência de infecções polimicrobianas nas infecções precoces e iii) IAP com culturas negativas ocorre em, aproximadamente, um quarto dos pacientes.

Accuracy of Serological Markers, Synovial Fluid, Microbiological Culture, and Histopathological Examination for Diagnosing Periprosthetic Knee Infection / Acurácia dosmarcadores sorológicos, do líquido sinovial, cultura microbiológica e exame histopatológico para o diagnóstico de infecção periprotética do joelho

Abstract Objective This study assessed the sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of serological tests, synovial fluid markers, microbiological tissue culture, and histopathological examination of the periprosthetic membrane in diagnosing periprosthetic knee infection. Methods This study is prospective, and it includes patients undergoing total knee arthroplasty revision surgery from November 2019 to December 2021. The analysis consisted of serological tests (erythrocyte sedimentation rate [ESR], C-reactive protein [CRP], and D-dimer), synovial fluid markers (leukocyte and polymorphonuclear cell counts), periprosthetic tissue culture, and histopathological examination of the periprosthetic membrane of all patients. Results Sixty-two patients had periprosthetic joint infection (PJI) according to the 2018 International Consensus Meeting criteria (infection group), while 22 subjects had no infection. ESR sensitivity and specificity were 83.6% and 45.4%, respectively. CRP sensitivity and specificity were 64.5% and 100%, whereas D-dimer sensitivity and specificity were 78.9% and 25%, respectively. Leukocyte count sensitivity and specificity were 75.6% and 100%, polymorphonuclear cell count sensitivity and specificity were 33% and 100%, respectively. Periprosthetic tissue culture sensitivity and specificity culture were, respectively, 77.4% and 100%. Histopathological examination sensitivity and specificity were 43.7% and 100%, respectively. Conclusions In our study, the total blood cell count in synovial fluid and microbiological cultures of periprosthetic tissues were the most accurate tests for PJI diagnosis. In contrast, polymorphonuclear cell percentage was the least accurate test for PJI diagnosis.

Resumo Objetivo avaliar a sensibilidade, especificidade, valor preditivo positivo, valor preditivo negativo e acurácia dos testes sorológicos, dos marcadores do líquido sinovial, da cultura microbiológica de tecidos e do exame histopatológico da membrana periprotética para o diagnóstico de infecção periprotética do joelho. Métodos estudo prospectivo, com pacientes submetidos à cirurgia de revisão de artroplastia total do joelho no período entre novembro de 2019 e dezembro de 2021. Foi realizado análise do marcadores sorológicos (VHS,PCR e D-dímero), do líquido sinovial (contagem de leucócitos e percentual de polimorfonucleares), cultura de tecidos periprotéticos e exame histopatológico da membrana periprotética de todos os pacientes. Resultados 62 pacientes foram diagnosticados com infecção periprotética do joelho, pelos critérios do International Consensus Meeting 2018 (grupo infecção) e 22 pacientes integraram o grupo não infecção. A sensibilidade e especificidade da VHS foram de 83,6% e 45,4%, respectivamente. Os valores de sensibilidade e especificidade da PCR foram de 64,5% e 100% e as do D-dímero foram de 78,9%% e 25%, respectivamente. A sensibilidade e especificidade da contagem de leucócitos foi de 75,6% e 100%, e a do percentual de polimorfonucleares foi de 33% e 100%, respectivamente. A sensibilidade e especificidade das culturas de tecidos periprotéticos foi de, respectivamente, 77,4% e 100% A sensibilidade do exame histopatológico foi de 43,7% e a especificidade de 100%. Conclusões A contagem total de leucócitos no líquido sinovial e as culturas microbiológicas dos tecidos periprotéticos foram os testes de maior acurácia para o diagnóstico de infecção periprotética em nossa série. O percentual de polimorfonucleares foi o teste de menor acurácia, em nosso estudo, para o diagnóstico de infecção periprotética.

Surgical management of aged complex sacral injuries by lumbopelvic stabilization / Manejo cirúrgico das lesões complexas envelhecidas do sacro por estabilização lombopélvica / Manejo quirúrgico de lesiones complejas envejecidas del sacro por estabilización lumbopélvica

ABSTRACT Objective: Evaluate the surgical indications, epidemiological data, radiographic outcomes, and postoperative complications of 16 cases of aged complex sacral fractures treated using bilateral spinopelvic fixation (PEF) or triangular osteosynthesis (OT) techniques in a case referral service. Traumatology and orthopedics complexes. Methods: A longitudinal study based on a retrospective review of patients' medical records with complex sacral fractures admitted between 2014 and 2020. All patients over 18 years of age whose time of evolution between the trauma and the surgical procedure was greater than or equal to three weeks were included. Results: The mean age was 39.8 years (18 to 71). Anterior pelvic ring injuries represented the most common association, present in 12 (75%) cases. In 8 (50%) cases, there was no neurological injury, 1 (6.2%) individual evolved with paresthesia, 2 (12.5%) with paresis in the lower limbs, and 5 (31.3%) with sphincter dysfunctions. Among the patients with neurological impairment, 4 (50%) evolved with complete improvement, 2 (25%) showed partial improvement, and 2 (25%) cases remained with the deficit. The mean surgical time was 3.6 hours for OT and 4.9 hours for FEP. Postoperative complications occurred in 4 (44.4%) patients who underwent PEF, and there were no postoperative complications in the OT group. Conclusions: The surgical management of these lesions using OT and FEP proved safe and effective. The minimum follow-up was 12 months, and all the individuals analyzed showed good evolution. Level of evidence IV; case series.

RESUMO Objetivo: Avaliar as indicações cirúrgicas, dados epidemiológicos, desfechos radiográficos e complicações pós operatórias de uma série de 16 casos de fraturas complexas envelhecidas do sacro tratadas através das técnicas de fixação espinopélvica bilateral (FEP) ou osteossíntese triangular (OT) em um serviço de referência de casos complexos de traumatologia e ortopedia. Métodos: estudo longitudinal, baseado na revisão retrospectiva de prontuários de pacientes com fraturas complexas do sacro, admitidos entre 2014 e 2020. Foram incluídos todos os pacientes acima de 18 anos cujo tempo de evolução entre o trauma e o procedimento cirúrgico foi maior ou igual a três semanas. Resultados: A média de idade foi de 39,8 anos (18 a 71 anos). As lesões do anel pélvico anterior representaram a associação mais comum, presentes em 12 (75%) casos. Em 8 (50%) casos não ocorreu lesão neurológica, 1 (6,2%) indivíduo evoluiu com parestesia, 2 (12,5%) com paresia nos membros inferiores e 5 (31,3%) com disfunções esfincterianas. Entre os pacientes com comprometimento neurológico, 4 (50%) evoluíram com melhora completa, 2 (25%) apresentaram melhora parcial e 2 (25%) casos permaneceram com o déficit. O tempo médio cirúrgico foi 3,6 horas para OT e 4,9 horas para FEP. Ocorreram complicações pós-operatórias em 4 (44,4%) pacientes que realizaram FEP e não houve complicações pós-operatórias no grupo submetido a OT. Conclusões: O manejo cirúrgico dessas lesões por meio da OT e FEP se mostrou seguro e eficaz. O seguimento mínimo foi de 12 meses e todos os indivíduos analisados apresentaram boa evolução. Nível de evidência IV; série de casos.

RESUMEN Objetivo: Evaluar las indicaciones quirúrgicas, datos epidemiológicos, resultados radiográficos y complicaciones postoperatorias de una serie de 16 casos de fracturas de sacro envejecidas y complejas tratadas mediante las técnicas de fijación espino pélvica bilateral (FEP) u osteosíntesis triangular (OT) en un servicio de referencia de traumatología y ortopedia. Métodos: estudio longitudinal, basado en una revisión retrospectiva de expedientes clínicos de los pacientes con fracturas sacras complejas ingresados entre 2014 y 2020. Se incluyeron en el estudio todos los pacientes mayores de 18 años cuyo tiempo de evolución entre el trauma y el procedimiento quirúrgico fue mayor o igual a tres semanas. Resultados: La edad promedio fue de 39,8 años (18 a 71 años). Las lesiones anteriores del anillo pélvico representaron la asociación más frecuente, presente en 12 (75%) casos. En 8 (50%) casos no hubo lesión neurológica, 1 (6,2%) evolucionó con parestesia, 2 (12,5%) con paresia en miembros inferiores y 5 (31,3%) con disfunción esfinteriana. Entre los pacientes con deterioro neurológico, 4 (50%) evolucionaron con mejoría completa, 2 (25%) mostraron mejoría parcial y 2 (25%) casos permanecieron con déficit. El tiempo quirúrgico promedio fue de 3,6 horas para OT y de 4,9 horas para FEP. Las complicaciones postoperatorias ocurrieron en 4 (44,4%) pacientes que se sometieron a FEP y no hubo complicaciones postoperatorias en el grupo OT. Conclusiones: El manejo quirúrgico de estas lesiones mediante OT y FEP demostró ser seguro y efectivo. El seguimiento mínimo fue de 12 meses y todos los individuos analizados mostraron una buena evolución. Nivel de evidencia IV; Series de casos.

The Role of the Resident Doctor in Orthopedics and Traumatology in a Large Hospital of the Unified Health System: What is the User's view?

Objective To assess the knowledge of patients seen at a teaching hospital about the academic and professional training of the resident doctor in orthopedics and traumatology, as well as his area of expertise, and determine the perception of the patients of comfort and safety in relation to being assisted by the resident doctor at different stages of treatment. Methods A cross-sectional study was conducted with patients admitted to a large orthopedics hospital of the Brazilian Unified Health System (SUS, in the Portuguese acronym). Data were collected through the application of a questionnaire containing 19 objective questions that assessed sociodemographic parameters and the perception of the patient of the performance of the resident. The data were analyzed to assess the frequency of responses obtained. Results 152 participants were evaluated, predominantly male (62.6%) and aged between 36 and 55 years old (41.3%). Only 43.3% were aware of the academic background of the resident. Patients reported feeling safer and more comfortable being assisted by the doctor together with the resident in the outpatient consultation (43.3%), in the nursing ward (39.3%) and during surgery (61%). As for the performance of the resident, 80.2% stated that the resident doctor improves communication between the patient and the main surgeon; however, only 11% said they would feel safe and comfortable being cared for exclusively by residents in the surgical environment, if allowed. Conclusion The participation of resident physicians in the care is well received by the patients if they are in the company of the attending physician. Patients identify residents as a facilitating bridge in the communication with attending physicians.

How to Create an Arthroscopy Training Laboratory Using a Bovine Knee Model.

Orthopaedic surgeries by video arthroscopy have become increasingly popular, as they allow joint treatment through small incisions and minimal tissue damage. However, their execution requires specific skills from the surgeon, different from open surgery, which can only be achieved through practical training. These skills would be ideally performed on human cadaveric anatomical pieces which, however, can be difficult to access for different reasons. Animal anatomical models for surgical skills training have been used for years in medicine, and we observed that the bovine knee has anatomical characteristics quite similar to that of the human knee. In this study, we explain, step by step, the installation and creation of an arthroscopy laboratory with a bovine model, in an effort to contribute to several training centers in arthroscopic surgery around the world, assisting and guiding such centers to install arthroscopy laboratories and facilitating the improvement of more surgeons.

The Role of the Resident Doctor in Orthopedics and Traumatology in a Large Hospital of the Unified Health System: What is the User's view? / A atuação do médico residente em ortopedia e traumatologia em um hospital de grande porte do Sistema Único de Saúde: Qual a visão do usuário?

Abstract Objective To assess the knowledge of patients seen at a teaching hospital about the academic and professional training of the resident doctor in orthopedics and traumatology, as wellas his areaofexpertise, and determinethe perception of thepatients ofcomfort and safety in relation to being assisted by the resident doctor at different stages of treatment. Methods A cross-sectional study was conducted with patients admitted to a large ortho pedics hospital of the Brazilian Unified Health System(SUS, in the Portugues e acronym). Datawere collected through the application of a questionnaire containing 19 objective questions that assessed sociodemographic parameters and the perception of the patient of the performance of the resident. The data were analyzed to assess the frequency of responses obtained. Results 152 participantswere evaluated, predominantlymale(62.6%)andaged between 36 and 55 years old (41.3%). Only 43.3% were aware of the academic background of the resident. Patients reportedfeelingsaferandmorecomfortablebeingassistedbythedoctor together with the resident in the outpatient consultation (43.3%), in the nursing ward (39.3%)andduringsurgery(61%).Asfor theperformanceof theresident,80.2%statedthat the resident doctor improves communication between the patient and the main surgeon; however, only 11% said they would feel safe and comfortable being cared for exclusively by residents in the surgical environment, if allowed. Conclusion The participation of resident physicians in the care is well received by the patients if they are in the company of the attending physician. Patients identify residents as a facilitating bridge in the communication with attending physicians.

Resumo Objetivo Avaliar o conhecimento de pacientes atendidos em um hospital-escola acerca da formação acadêmica e profissional do médico residente em ortopedia e traumatologia, bem como sua área de atuação, e determinar a percepção de conforto e segurança do paciente em relação a ser assistido pelo médico residente em diferentes etapas do tratamento. Métodos Foi realizado um estudo transversal com pacientes internados em um hospital de ortopedia de grande porte do Sistema Único de Saúde (SUS). Os dados foram coletados a partir da aplicação de um questionário contendo 19 questões objetivas que avaliaram parâmetros sociodemográficos e a percepção do paciente quanto à atuação do residente. Os dados foram analisados de forma a avaliar a frequência das respostas obtidas. Resultados Foram avaliados 152 participantes, predominantemente do sexo masculino (62,5%) e com idade entre 36 e 55 anos (41,3%). Apenas 43,3% tinham conhecimento sobre a formação acadêmica do residente. Os pacientes relataram se sentir mais seguros e confortáveis em serem assistidos pelo médico em conjunto com o residente na consulta ambulatorial (43,3%), na enfermaria (39,3%) e durante a cirurgia (61%). Quanto à atuação do residente, 80,2% afirmaram que o médico residente melhora a comunicação entre o paciente e o cirurgião principal, entretanto e apenas 11% disseram se sentir seguros e confortáveis sendo cuidados exclusivamente por residentes no ambiente cirúrgico, caso fosse permitido. Conclusão A participação de médicos residentes nos cuidados é bem recebida pelos pacientes, desde que em companhia do médico assistente. Os pacientes identificam nos residentes uma ponte facilitadora na comunicação com os médicos assistentes.

PTH1-34 improves devitalized allogenic bone graft healing in a murine femoral critical size defect.

The treatment of large segmental defects of long bones resulting from trauma, infection, or bone tumor resections is a major challenge for orthopedic surgeons. The reconstruction of bone defects with acellular allografts can be used as an osteoconductive approach. However, devitalized allografts are associated with high rates of clinical failure as a result of poor intrinsic osteoinduction properties and a lack of further remodeling. Nevertheless, evidence suggests that due to its anabolic properties, teriparatide (PTH1-34) could be effective as an adjuvant therapy for massive allograft healing. Therefore, our goal was to investigate in a murine critical-sized defect model whether the intermittent administration of PTH1-34 improves the incorporation and revitalization of acellular structural bone allografts. Thus, a 2.5-mm critical-sized defect was established in the right femur of C57BL/6 mice, followed by the reconstruction with a devitalized cortical structural allograft. A titanium micro locking plate was applied to the anterior femoral surface and secured in place with self-tapping locking screws. Subsequently, daily doses of PTH1-34 (30, and 40 µg/kg) or saline were administered to the mice for 14 days after surgery. The mice were maintained without PTH1-34 therapy for an additional 7 days before being euthanized at 3 weeks post-surgery. Bone graft consolidation was assessed on radiographic images and by histomorphometric analysis. Additionally, to determine the frequency of osteoprogenitor cells in the bone marrow and their in vitro osteogenic capacity, stromal cells were isolated from the bone marrow of animals treated with 30 or 40 µg/kg/day of PTH1-34 following the same protocol used for the experimental animals. Our results suggest that intermittent PTH1-34 treatment at 30 µg/kg/day after femoral allograft reconstruction surgery accelerated the healing process as evidenced by new bone formation induced on endosteal and periosteal surfaces, enhanced revitalization of allogeneic graft, and increased frequency and osteogenic capacity of bone marrow stromal cells (BMSC). These findings should encourage further studies aimed at investigating the potential therapeutic use of intermittent PTH1-34, specifically with regards to the optimal dosing regimen in clinically challenging orthopedic scenarios.

Impact of the Strategies Adopted to Face the COVID-19 Pandemic in a Brazilian Reference Institute for High Complexity Surgery in Orthopedics and Traumatology.

COVID-19 pandemics required substantial reorganization and adaptation of healthcare services all over the world. This study aims to analyze the effect of operational strategies implemented in Brazil to manage the extra strain placed on healthcare services by the COVID-19 pandemic of 2020. In particular, this investigation examines the strategy to convert an institute specialized in elective orthopedic procedures of high complexity into a trauma unit for all musculoskeletal trauma patients of an entire federative unit. A retrospective study was conducted comparing hospital variables at the peak period of the pandemic (from March 16, 2020 to June 30, 2020) with the same period in 2019 as a comparative baseline. The variables analyzed included number of professionals away from work, surgeries performed, outpatient care, transfers, length of stay, number of patients diagnosed with COVID-19 and patient mortality. During the COVID-19 peak period, there was a 48.5% reduction in surgical productivity and 72.4% reduction in outpatient care compared with the same period in 2019. The number of transfers increased substantially (124.5%), while 94 confirmed cases and 77 suspected cases of COVID-19 were reported. The mortality rate increased by 245%. The present study highlighted the effect of COVID-19 on a tertiary orthopedic hospital. Despite the dramatic changes in hospital operations, due to the implementation of protocols to manage the pandemic, the results demonstrated the feasibility and efficiency of such protocols in prioritizing quality and safety for patients and the healthcare workforce.

Impact of the Strategies Adopted to Face the COVID-19 Pandemic in a Brazilian Reference Institute for High Complexity Surgery in Orthopedics and Traumatology / Impacto das estratégias adotadas para enfrentar a pandemia de COVID-19 em um Instituto Brasileiro de referência em cirurgia de alta complexidade em Ortopedia e Traumatologia

Abstract COVID-19 pandemics required substantial reorganization and adaptation of healthcare services all over the world. This study aims to analyze the effect of operational strategies implemented in Brazil to manage the extra strain placed on healthcare services by the COVID-19 pandemic of 2020. In particular, this investigation examines the strategy to convert an institute specialized in elective orthopedic procedures of high complexity into a trauma unit for all musculoskeletal trauma patients of an entire federative unit. A retrospective study was conducted comparing hospital variables at the peak period of the pandemic (from March 16, 2020 to June 30, 2020) with the same period in 2019 as a comparative baseline. The variables analyzed included number of professionals away from work, surgeries performed, outpatient care, transfers, length of stay, number of patients diagnosed with COVID-19 and patient mortality. During the COVID-19 peak period, there was a 48.5% reduction in surgical productivity and 72.4% reduction in outpatient care compared with the same period in 2019. The number of transfers increased substantially (124.5%), while 94 confirmed cases and 77 suspected cases of COVID-19 were reported. The mortality rate increased by 245%. The present study highlighted the effect of COVID-19 on a tertiary orthopedic hospital. Despite the dramatic changes in hospital operations, due to the implementation of protocols to manage the pandemic, the results demonstrated the feasibility and efficiency of such protocols in prioritizing quality and safety for patients and the healthcare workforce.

Resumo A pandemia de COVID-19 exigiu reorganização e adaptação substanciais dos serviços de saúde em todo o mundo. Este estudo tem como objetivo analisar o efeito das estratégias operacionais implementadas no Brasil em resposta à pressão extra imposta aos serviços de saúde pela pandemia de COVID-19 de 2020. Esta pesquisa examina principalmente a estratégia de conversão de um instituto especializado em procedimentos ortopédicos eletivos de alta complexidade em uma unidade de trauma para todos os pacientes com traumatismo musculoesquelético de toda uma unidade federativa. Um estudo retrospectivo comparou as variáveis hospitalares no período de pico da pandemia (de 16 de março de 2020 a 30 de junho de 2020) com o mesmo período de 2019, que representou os valores basais. As variáveis analisadas foram número de profissionais afastados do trabalho, cirurgias realizadas, atendimento ambulatorial, transferências, tempo de internação, número de pacientes com diagnóstico de COVID-19 e mortalidade dos pacientes. Durante o período de pico de COVID-19, houve uma redução de 48,5% na produtividade cirúrgica e de 72,4% no atendimento ambulatorial em comparação ao mesmo período de 2019. O número de transferências aumentou de maneira substancial (124,5%), com relato de 94 casos confirmados e 77 casos suspeitos de COVID-19. A taxa de mortalidade aumentou 245%. Este estudo destacou o efeito da COVID-19 em um hospital ortopédico terciário. Apesar das mudanças dramáticas no funcionamento do hospital devido à instituição de protocolos em resposta à pandemia, os resultados demonstraram a viabilidade e a eficiência de tais protocolos em priorizar a qualidade e a segurança dos pacientes e dos profissionais de saúde.

Nitric oxide impacts bovine sperm capacitation in a cGMP-dependent and cGMP-independent manner.

We aimed to elucidate whether NO acts in in vitro sperm capacitation in bovine via cGMP/PKG1 pathway. For this, cryopreserved bovine sperm were capacitated in vitro with 20 µg/ml heparin (Control) plus treatments: 1 mM L-arginine (L-arg, NO precursor), 50 µM Rp-8-Bromo-ß-phenyl-1,N2 -ethenoguanosine-3',5'-cyclic monophosphorothioate (Rp-8-Br-cGMPS, selective inhibitor of the binding site for cGMP in PKG1), 1 mM 2-Phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl 3-oxide (PTIO, NO scavenger), and the combinations of L-arg + RP-8-Br-cGMPS and L-arg + PTIO. Sperm motility and vigour were determined by phase-contrast microscopy, capacitation status by chlortetracycline staining, and the intracellular concentration of cGMP was measured by ELISA. Data were subjected to analysis of variance and means compared with SNK test at 5% probability. Motility and vigour were lower in sperm treated with PTIO when compared to Control and other treatments (p < .05). The L-arg treatment showed the highest percentage of capacitated sperm when compared to the Control and other treatments (Rp-8-Br-cGMPS, L-arg + Rp-8-Br-cGMPS and PTIO) (69.8 ± 3.4%, 51.2 ± 3.0, 51.1 ± 2.1, 51.2 ± 3.0 and 45.5 ± 2.7, respectively) (p < .05). The capacitation ratio (%) was lower in treatments with Rp-8-Br-cGMPS, L-arg + Rp-8-Br-cGMPS and PTIO, respectively (p < .05). Lastly, cGMP concentration (pmol/ml) was lower in PTIO and L-arg + PTIO (1.3 ± 0.3 and 1.6 ± 0.4) and was higher in Rp-8-Br-cGMPS and L-arg + Rp-8-Br-cGMPS (3.7 ± 0.4 and 4.0 ± 0.5) treatments. We showed that during in vitro capacitation of cattle: (a) NO influences sperm motility and vigour; (b) NO is associated with cGMP synthesis through two independent pathways and (c) the cGMP/PKG1 pathway has a partial role in sperm capacitation and does not involve the L-arg/NO.

Breast-cancer extracellular vesicles induce platelet activation and aggregation by tissue factor-independent and -dependent mechanisms.

INTRODUCTION: Cancer-associated thrombosis is one of the major causes of worse prognosis among tumor-bearing patients. Extracellular vesicles derived from cancer cells, which can be divided mainly into microvesicles and exosomes, can participate in several tumor progression phenomena. Tumor-derived microvesicles positive for tissue factor (TF) have been associated with thrombotic risk in certain cancer types. Cancer cell-derived exosomes, however, have not. In this study we evaluated the capacity of extracellular vesicles (EVs, containing both microvesicles and exosomes) derived from breast-cancer cell lines in promoting platelet activation, aggregation and plasma coagulation, in experiments that access both TF-dependent and -independent activities. MATERIALS AND METHODS: EVs were isolated from the conditioned media of two human mammary carcinoma cell lines: MDA-MB-231 (highly invasive) and MCF-7 (less invasive). TF-independent EV/platelet interaction, platelet P-selectin exposure and aggregation were evaluated. Western blotting, plasma clotting and platelet aggregation in the presence of plasma were performed for the measurement of TF-dependent activity in EVs. RESULTS: Interaction between MDA-MB-231 EVs and washed platelets led to increased platelet P-selectin exposure and platelet aggregation compared to MCF-7 EVs. MDA-MB-231 EVs had higher TF protein levels and TF-dependent procoagulant activity than MCF-7 EVs. Consequently, TF-dependent platelet aggregation was also induced by MDA-MB-231 EVs, but not by MCF-7 EVs. CONCLUSION: Our results suggest that MDA-MB-231 EVs induce TF-independent platelet activation and aggregation, as well as TF-dependent plasma clotting and platelet aggregation by means of thrombin generation. In this context, aggressive breast cancer-derived EVs may contribute to cancer-associated thrombosis.

Intercellular transfer of tissue factor via the uptake of tumor-derived microvesicles.

Coagulation proteins play a critical role in numerous aspects of tumor biology. Cancer cells express tissue factor (TF), the protein that initiates blood clotting, which frequently correlates with processes related to cell aggressiveness, including primary tumor growth, invasion, and metastasis. It has been demonstrated that TF gets incorporated into tumor-derived microvesicles (MVs), a process that has been correlated with cancer-associated thrombosis. Here, we describe the exchange of TF-bearing MVs between breast cancer cell lines with different aggressiveness potential. The highly invasive and metastatic MDA-MB-231 cells displayed higher surface levels of functional TF compared with the less aggressive MCF-7 cells. MVs derived from MDA-MB-231 cells were enriched in TF and accelerated plasma coagulation, but MCF-7 cell-derived MVs expressed very low levels of TF. Incubating MCF-7 cells with MDA-MB-231 MVs significantly increased the TF activity. This phenomenon was not observed upon pretreatment of MVs with anti-TF or annexin-V, which blocks phosphatidylserine sites on the surface of MVs. Our data indicated that TF-bearing MVs can be transferred between different populations of cancer cells and may therefore contribute to the propagation of a TF-related aggressive phenotype among heterogeneous subsets of cells in a tumor.

T cells induce pre-metastatic osteolytic disease and help bone metastases establishment in a mouse model of metastatic breast cancer.

Bone metastases, present in 70% of patients with metastatic breast cancer, lead to skeletal disease, fractures and intense pain, which are all believed to be mediated by tumor cells. Engraftment of tumor cells is supposed to be preceded by changes in the target tissue to create a permissive microenvironment, the pre-metastatic niche, for the establishment of the metastatic foci. In bone metastatic niche, metastatic cells stimulate bone consumption resulting in the release of growth factors that feed the tumor, establishing a vicious cycle between the bone remodeling system and the tumor itself. Yet, how the pre-metastatic niches arise in the bone tissue remains unclear. Here we show that tumor-specific T cells induce osteolytic bone disease before bone colonization. T cells pro-metastatic activity correlate with a pro-osteoclastogenic cytokine profile, including RANKL, a master regulator of osteoclastogenesis. In vivo inhibition of RANKL from tumor-specific T cells completely blocks bone loss and metastasis. Our results unveil an unexpected role for RANKL-derived from T cells in setting the pre-metastatic niche and promoting tumor spread. We believe this information can bring new possibilities for the development of prognostic and therapeutic tools based on modulation of T cell activity for prevention and treatment of bone metastasis.