Research progress on biomechanics for internal fixation in tibial plateau fracture / 中国修复重建外科杂志

OBJECTIVE@#To review the biomechanical research progress of internal fixation of tibial plateau fracture in recent years and provide a reference for the selection of internal fixation in clinic.@*METHODS@#The literature related to the biomechanical research of internal fixation of tibial plateau fracture at home and abroad was extensively reviewed, and the biomechanical characteristics of the internal fixation mode and position as well as the biomechanical characteristics of different internal fixators, such as screws, plates, and intramedullary nails were summarized and analyzed.@*RESULTS@#Tibial plateau fracture is one of the common types of knee fractures. The conventional surgical treatment for tibial plateau fracture is open or closed reduction and internal fixation, which requires anatomical reduction and strong fixation. Anatomical reduction can restore the normal shape of the knee joint; strong fixation provides good biomechanical stability, so that the patient can have early functional exercise, restore knee mobility as early as possible, and avoid knee stiffness. Different internal fixators have their own biomechanical strengths and characteristics. The screw fixation has the advantage of being minimally invasive, but the fixation strength is limited, and it is mostly applied to Schatzker typeⅠfracture. For Schatzker Ⅰ-Ⅳ fracture, unilateral plate fixation can be used; for Schatzker Ⅴand Ⅵ fracture, bilateral plates fixation can be used to provide stronger fixation strength and avoid the stress concentration. The intramedullary nails fixation has the advantages of less trauma and less influence on the blood flow of the fracture end, but the fixation strength of the medial and lateral plateau is limited; so it is more suitable for tibial plateau fracture that involves only the metaphysis. Choosing the most appropriate internal fixation according to the patient's condition is still a major difficulty in the surgical treatment of tibial plateau fractures.@*CONCLUSION@#Each internal fixator has good fixation effect on tibial plateau fracture within the applicable range, and it is an important research direction to improve and innovate the existing internal fixator from various aspects, such as manufacturing process, material, and morphology.

Hp infection rate, antibody typing and logistics regression analysis of 1111 physical examination people in plateau area / 公共卫生与预防医学

Objective To explore the Helicobacter pylori (Hp) infection rate and antibody typing of 1111 physical examination people in plateau area, and to analyze the risk factors of Hp infection by logistics regression analysis. Methods 1111 healthy people with physical examination in plateau area from January 2022 to December 2022 were selected as the research subjects. The Hp infection rate and antibody typing were calculated, and the risk factors of Hp infection were analyzed by logistics regression analysis. Results The Hp infection rate of physical examination people in plateau area was 62.47% (694/1 111). The infection rate of type I HP in infected patients was higher than that of type Ⅱ HP(75.50% vs 24.50%) (χ2=361.141, P2=4.418, 8.708, 16.565, 32.583, P=0.036, 0.003, 2=5.153, P=0.023). Often eating pickled or barbecued foods [OR (95%CI)=2.038 (1.049-3.961)], history of chronic gastric disease [OR(95%CI)=1.706 (1.132-2.569)] and family members living together≥4 [OR (95%CI)=1.857 (1.135-3.037)] were risk factors of Hp infection, and regular garlic consumption [OR (95%CI)=0.559 (0.346-0.903)] was a protective factor (P=0.036, 0.011, 0.014, 0.018). Conclusion The Hp infection rate and antibody Ure positive rate are higher in physical examination people in plateau area, and chronic gastric disease history and often eating pickled or barbecued foods are risk factors of Hp infection.

Effects of plateau environment on tear indexes and related anatomical structures of rabbits / 国际眼科杂志(Guoji Yanke Zazhi)

AIM: To investigate the effects of hypobaric hypoxia in plateau on tear indexes and related anatomical structures in rabbits.METHODS: A total of 18 healthy New Zealand rabbits were selected and randomly divided into plateau group and control group, with 9 rabbits(18 eyes)in each group. The plateau group was housed in the Simulated Climate Cabin for Special Environment of Northwest of China, simulating hypobaric hypoxia at an altitude of 6 000 m. The control group was housed in a clean animal room with atmospheric pressure and oxygen. Changes in the tear meniscus height and non-invasive tear break-up time were detected by using RHCT-1 corneal topographer dry eye comprehensive analysis system, changes in tear secretion was measured by Schirmer Ⅰ test, before intervention and on the 3, 7 d, 2 and 4 wk. Meanwhile, the changes in tear composition before and after intervention in the plateau environment were analyzed using Raman Spectroscopy. The histopathological changes of the lower lid conjunctiva, cornea, lacrimal gland, and Hardarian gland were observed by hematoxylin-eosin(HE)staining after 4 wk of intervention, and the expression of mucin 5AC(MUC5AC)in conjunctiva was detected by immunohistochemistry.RESULTS: Compared with the control group, Schirmer Ⅰ test, tear meniscus height, first and average non-invasive tear break-up time in the plateau group decreased significantly since 3 d, and the difference was significant with the extension of observation time(P<0.05). The above indexes increased from 2 wk. After 4 wk of intervention, the protein and lipid content of the tear composition of rabbits in the plateau group increased, and the nucleic acid content decreased compared with the pre-intervention period. Compared with the control group, rabbits in the plateau group showed thickening of corneal stromal edema, an increase in the number of conjunctival cup cells, increase in the level of expression of MUC5AC, an increase in the level of expression of MUC5AC, an atrophy and flattening of cytoplasm in lacrimal epithelial cells, an enlargement of glandular lumen, and no obvious destructive changes in the Hardarian glands.CONCLUSION: Acute plateau environment can destroy the homeostasis of rabbit ocular surface, so that the tear secretion and the tear film stability decreases, but within a certain period of time, rabbits undergo compensation with the habituation to the hypobaric hypoxia environment, which can increase the tear secretion to a certain extent and restore the tear film stability.

A comparative study on the functional outcomes of patients who underwent internal versus external fixation for Tibial Plateau fractures two years post-surgery

Introduction@#Tibial plateau fractures are due to high energy trauma brought about by axial compression forces and associated varus or valgus component. @*Objective@#Patients diagnosed with tibial plateau fractures from January to December 2018 treated with internal vs. external fixation will be described according to their Schatzker classification. The study further aims to compare the functional outcomes between the two groups in terms of surgery done. @*Methods@#A chart review determined the distribution of demographics. The Modified Rasmussen Score (MRS) was used to determine the clinical and radiographic parameters after taking a new knee radiograph and assessment from the rehabilitation department. The MRS determined the functional outcomes of the said patients. Ethical considerations and proper informed consent were upheld after being reviewed by the hospital’s research committee. @*Results@#Out of 48 patients, 35 underwent internal fixation via open reduction using plates and/or screws, while 13 underwent external fixation using hybrid external fixator. The demographic profile showed mostly males between ages 20 to 49 years old. Most cases were due to vehicular accidents affecting the left lower extremity. In terms of Schatzker classification, the most common was type VI. The computed mean MRS of the internal fixation group was 30.43 while the external fixation group was 30.00, generally showing no significant difference. @*Conclusion@#Surgical intervention of tibial plateau fractures aims for anatomic reduction using internal or external fixation. There was no significant difference on the functional outcome of the two groups despite classifying the respondents according to Schatzker type, hence we can conclude that external fixation be chosen as the treatment of choice for tibial plateau fractures when properly indicated.

Abordaje posterior en fracturas de meseta tibial complejas en pacientes tratados quirúrgicamente en el IAHULA / Posterior approach in complex tibial plateau fractures IAHUL A Surgically treated patients

Las fracturas de meseta tibial compleja se asocian a traumatismo de alta energía, principalmente en accidentes de motocicleta, siendo un desafío para el cirujano ortopedista. En la década de 1970, Schatzker propuso una clasificación radiológica para las fracturas de la meseta tibial, que destacaba la morfología de los seis tipos principales. Las imágenes de tomografía computarizada y tridimensional, han cambiado la comprensión y el tratamiento de las fracturas de la meseta tibial. Recientemente, esa clasificación original se complementó con una más amplia; puesto que, se introdujo el fragmento en cuña dividida y la continuidad de la columna posterior como determinantes de la estabilidad articular y el papel fundamental que desempeña en el tratamiento de las fracturas de la meseta tibial, con ellos también la importancia de abordajes quirúrgicos que permitan la visualización posterior para una adecuada reducción. El estudio documenta las técnicas de fijación interna y abordajes posteriores realizadas en el IAHULA, valorando los resultados clínicos en cuanto a dolor y satisfacción del paciente, como consolidación, pseudoartrosis o falla en la técnica de osteosíntesis realizada. El resultado a partir de las escalas de evaluación de la AO y KOOS, arrojaron que, con un efecto excelentes se agrupa un 28,6% y bueno a un 42,9%, indicando la importancia de la fijación de la columna posterior, para prevenir artrosis postraumática temprana e inestabilidad articular(AU)

A complex fracture of the posterior tibial plateau are related to high energy traumatisms, mainly during motorcycle accidents, becoming a challenge to the ortopedic surgen. During the seventies, Stchatzker proposed a radiologic classification for the tibial plateau fractures that pointed the morphology of six main types. The computarized and tridimensional tomographic images have changed the comprehension and treatment of these fractures. Recently, the original classification was complemented with a more broaded approach due to the introduction of the fragment in divided crib and the continuity of the posterior column as factors determining the articular stability and the fundamental roll played in the treatment of fractures of the tibial plateau, as well as the important roll of surgical approaches that allow the posterior visualization for a correct reduction. This research documents the technics of internal fixation and posterior approach developed in the IAHULA, evaluating the clinic results about patients' pain level and comfort, as well as the radiologic findings of consolidation, pseudoarthrosis, or fail in the technic of osteosynthesis developed. The results from a point of view of the evaluation scales of the AO and KOOS, show 28.6% with excellent outcomes, and 42.9% with good outcomes, indicating the importance of the fixation of the posterior column to prevent early start of posttraumatic arthrosis and articular instability(AU)

Rendimiento Biomecánico de las Placas de Tibia Proximal Utilizadas en Fracturas de Platillos Tibiales evaluado a través de Modelos de Elementos Finitos: Protocolo de Revisión Sistemática / A systematic Review Protocol Examining the Biomechanical Performance of Proximal Tibial Plates used in Tibial Plate Fractures assessed by Finite Element Analysis

Objetivo. Analizar el rendimiento biomecánico de las placas de tibia proximal utilizadas en fracturas de platillos tibiales evaluado a través de modelos de elementos finitos. Métodos. Se realizará una búsqueda exhaustiva en PubMed/Medline, Embase, Lilacs, Web of Science y Google Scholar. No se utilizará ninguna restricción de idioma o estado de publicación. Dos revisores examinarán de forma independiente los posibles artículos elegibles, de acuerdo con los criterios de selección predefinidos. Se incluirán los estudios que evalúen el rendimiento de los platillos tibiales proximales utilizados en las fracturas del platillo tibial evaluadas mediante el análisis de elementos finitos. La extracción de datos sobre las características del estudio, los métodos, los resultados y la evaluación del riesgo de sesgo se realizará mediante un formulario estandarizado. Considerando el diseño de estudio no se requiere evaluación por comité de ética. Los resultados de esta revisión se difundirán a través de la publicación en revistas revisadas por pares, redes sociales y congresos de la especialidad. Se espera que los resultados de esta revisión permitan optimizar los resultados del manejo quirúrgico de las fracturas de platillos tibiales. Número de registro PROSPERO: CRD42023396015.

Objetive. To analyze the biomechanical performance of proximal tibial plates used in tibial plate fractures evaluated through finite element modeling. Methods. A comprehensive search will be conducted in PubMed/Medline, Embase, Lilacs, Web of Science, and Google Scholar. No language or publication status restrictions will be used. Two reviewers will independently review potential eligible articles according to predefined selection criteria. Studies evaluating the performance of proximal tibial splints used in tibial splint fractures assessed by finite element analysis will be included. Data extraction on study characteristics, methods, results, and risk of bias assessment will be performed using a standardized form. Considering the study design, evaluation by an ethics committee is not required. The results of this review will be disseminated through publication in peer-reviewed journals, social networks and specialty congresses. It is expected that the results of this review will allow optimizing the results of the surgical management of tibial plate fractures. PROSPERO registration number: CRD42023396015.

Fracturas del platillo tibial con hundimiento articular. Comparación entre reconstrucción con injertos óseos y sustitutos sintéticos. Revisión bibliográfica sistematizada / Depressed tibial-plateau fractures, a comparison between bone graft reconstruction and synthetic substitutes. Systematic bibliographic review / Fraturas do platô tibial com afundamento da articulação: comparação entre reconstrução com enxerto ósseo e substitutos sintéticos

Objetivo: comparar si existe diferencia en resultados clínicos, radiológicos y funcionales con el uso de diferentes tipos de injertos óseos o sustitutos sintéticos, así como tiempo quirúrgico y consolidación para el tratamiento de fracturas de platillo tibial con hundimiento articular en pacientes mayores de 18 años. Material y método: se realizó una búsqueda sistematizada en bases de datos de literatura médica, PubMed, Lilacs, Scielo, Cochrane y portal Timbó. Se utilizaron términos "tibial plateau fracture", "bone grafting", "bone substitutes". Se incluyeron estudios comparativos en seres humanos, pacientes mayores de 18 años, fracturas de platillo tibial que asociaron hundimiento articular, en los cuales se realizó aporte de injerto óseo o material sintético. Artículos en español, inglés, portugués. Publicaciones enero 1980 y diciembre 2021. Se obtuvieron 10 artículos. Resultados: los tipos de injertos y sustitutos óseos encontrados fueron 10. Las muestras en sumatoria total 524 pacientes. La edad promedio fue 49 años. El promedio de seguimiento fue de 12 meses. Se dividieron los estudios en tres grupos: comparación entre injerto autólogo (IOA) e injerto alogénico, IOA con sustitutos sintéticos, y los que comparan sustitutos sintéticos entre sí. El aloinjerto y los sustitutos sintéticos demostraron no ser inferiores en resultados clínicos, funcionales e imagenológicos, mejorando los tiempos intraoperatorios y disminuyendo complicaciones en el sitio donante con respecto al IOA. Conclusiones: el IOA continúa siendo el gold standard a pesar de sus posibles complicaciones vinculadas al sitio donante. El aloinjerto y los sustitutos sintéticos representan una opción válida para tratar estas lesiones.

Objective: to find out whether there are clinical, radiological and functional differences when using different types of bone grafts or synthetic substitutes, as well as surgical times and consolidation to treat depressed tibial-plateau fractures in patients older than 18 years old. Method: a systematized search was conducted in medical literature, PubMed, Lilacs, Scielo, Cochrane and Timbó portal databases using the following terms: "tibial plateau fracture", "bone grafting", "bone substitutes". The study included comparative studies in human patients older than 18 years old with depressed tibial-plateau fractures who were treated with bone grafts or synthetic materials. Publications in Spanish, English and Portuguese, between January, 1980 and December, 2021 were included in the search, what resulted in 10 articles found. Results: there were 10 kinds of bone grafts and bone substitutes found. Samples added up to 524 patients. Average age was 49 years old. Average follow up was 12 months. Studies were divided into 3 groups: comparison between autologous bone grafts and allogenic bone grafts, comparison between autologous grafts and synthetic substitutes and studies comparing synthetic substitutes with one another. Allogenic grafts and synthetic grafts proved at least equivalent in terms of clinical, functional and imaging studies results, improving intraoperative times and reducing complications in donor site when compared to autologous grafts. Conclusions: autologous grafts continue to be the gold standard despite possible complications associated to the donor site, and allogenic grafts and synthetic substitutes constitute a valid option to treat these lesions.

Objetivo: comparar os resultados clínicos, radiológicos e funcionais com o uso de diferentes tipos de enxertos ósseos ou substitutos sintéticos, bem como tempo cirúrgico e consolidação para o tratamento de fraturas do platô tibial com colapso articular em pacientes com mais de 18 anos. Material e método: foi realizada busca sistemática nas bases de dados da literatura médica, PubMed, Lilacs, SciELO, Cochrane e portal Timbó. Utilizaram-se os termos "tibial plateau fracture", "bone grafting", "bone substitutes". Foram incluídos estudos comparativos incluindo seres humanos maiores de 18 anos e fraturas do platô tibial associadas a colapso articular, nas quais foi realizado enxerto ósseo ou sintético, publicados entre janeiro de 1980 e dezembro de 2021 em espanhol, inglês e português. Foram obtidos 10 artigos. Resultados: foram identificados 10 tipos de enxertos e substitutos ósseos. 524 pacientes com idade média de 49 anos foram estudados. O seguimento médio foi de 12 meses. Os estudos foram divididos em 3 grupos: comparação entre enxerto autólogo (IOA) e enxerto alogênico, IOA com substitutos sintéticos e substitutos sintéticos entre si. O aloenxerto e os substitutos sintéticos mostraram-se não inferiores nos resultados clínicos, funcionais e de imagem, melhorando os tempos intraoperatórios e reduzindo as complicações da área doadora em relação à IOA. Conclusões: o IOA continua a ser o padrão ouro apesar de suas possíveis complicações relacionadas ao local doador; tanto o aloenxerto como os substitutos sintéticos representam uma opção válida para tratar essas lesões.

Indirect evidence of following association between golden dorados (Salminus brasiliensis) and green anacondas (Eunectes murinus) in a Clearwater river of Midwest Brazil / Evidência indireta de associação de seguidor entre dourado (Salminus brasiliensis) e sucuri-verde (Eunectes murinus) em um rio de águas claras do Centro-Oeste do Brasil

Abstract On four occasions, the golden dorado (Salminus brasiliensis) was recorded following the green anaconda (Eunectes murinus) in a clearwater river of Midwest Brazil. These observations were considered as an indirect evidence of a following association known as "nuclear-follower feeding association", a condition in which the follower approach the nuclear when it somehow disturbs the substrate and form sediment clouds while foraging, taking the opportunity to feed during this situation. However, no direct observations of golden dorados getting some benefit from the activity of the green anacondas to feed were made. Nevertheless, as there is a varied list of vertebrates considered as nuclear species in the clearwater rivers of Midwest Brazil, it is to be expected that future observations may provide unusual information about nuclear-follower feeding association between fish and snakes in the Neotropics.

Resumo Em quatro ocasiões, o dourado (Salminus brasiliensis) foi registrado seguindo a sucuri-verde (Eunectes murinus) em um rio de águas claras do Centro-Oeste do Brasil. Essas interações foram consideradas como uma evidência indireta de uma associação de seguidor conhecida como "associação de alimentação nuclear-seguidor", uma condição na qual o seguidor se aproxima da espécie nuclear quando esta de alguma forma perturba o substrato e/ou forma nuvens de sedimentos enquanto forrageia, aproveitando a oportunidade para se alimentar durante essa situação. No entanto, observações diretas de dourados obtendo algum benefício da atividade das sucuris para se alimentar não foram feitas. No entanto, como há uma lista variada de vertebrados considerados como espécies nucleares nos rios de águas claras do Centro-Oeste do Brasil, é de se esperar que observações futuras possam fornecer informações incomuns sobre associações do tipo "nuclear-seguidor" entre peixes e serpentes na região Neotropical.

Effects of orientation and distance of goats on blast lung injury characteristics on a plateau above 4500-meter / 中华创伤杂志(英文版)

PURPOSE@#High explosives are used to produce blast waves to study their biological effects. The lungs are considered as the critical target organ in blast-effect studies. The degree of lung hemorrhaging is related to both the explosive power and the increased lung weight. We studied the characteristics of the biological effects from an air explosion of a thermobaric bomb in a high-altitude environment and the lethality and lung injury severity of goats in different orientations and distances.@*METHODS@#Goats were placed at 2.5, 3, 4, and 5 m from the explosion center and exposed them to an air blast at an altitude of 4700-meter. A group of them standing oriented to the right side and the other group seated facing the explosion center vertically. The lung injuries were quantified according to the percentage of surface area contused, and using the pathologic severity scale of lung blast injury (PSSLBI) to score the 4 injury categories (slight, moderate, serious and severe) as 1, 2, 3, and 4, respectively. The lung coefficient (lung weight [g]/body weight [kg]) was the indicator of pulmonary edema and was related to lung injury severity. Blast overpressure data were collected using blast test devices placed at matching locations to represent loadings to goats. All statistical analyses were performed using SPSS, version 26.0, statistical software (SPSS, Inc., Chicago, IL, USA).@*RESULTS@#In total, 127 goats were involved in this study. Right-side-standing goats had a significantly higher mortality rate than those seated vertical-facing (p < 0.05). At the 2.5 m distance, the goat mortality was nearly 100%, whereas at 5 m, all the goats survived. Lung injuries of the right-side-standing goats were 1 - 2 grades more serious than those of seated goats at the same distances, the scores of PSSLBI were significantly higher than the seated vertical-facing goats (p < 0.05). The lung coefficient of the right-side-standing goats were significantly higher than those of seated vertical-facing (p < 0.05). Mortality, PSSLBI, and the lung coefficient results indicated that the right-side-standing goats experienced severer injuries than the seated vertical-facing goats, and the injuries were lessened as the distance increased. The blast overpressure was consistent with these results.@*CONCLUSION@#The main killing factors of the thermobaric bomb in the high-altitude environment were blast overpressure, blast wind propulsions and burn. The orientation and distances of the goats significantly affected the blast injury severity. These results may provide a research basis for diagnosing, treating and protecting against injuries from thermobaric explosions.

Clinical effect of Kirschner wire intramedullary fixation in the treatment of pediatric both-bone forearm fractures at high altitude area / 中国骨伤

OBJECTIVE@#To explore the clinical effect of Kirschner wire intramedullary fixation in the treatment of both-bone forearm fractures in children of high altitude area.@*METHODS@#From August 2020 to December 2021, 19 children were treated with Kirschner wire intramedullary fixation including 11 males and 8 females, aged from 4 to 13 years old with an average of (8.16±2.71) years old. The course of disease was 1 to 10 days, with a mean of (4.11±2.51) d. First, close reduction was performed. If the reduction was unsuccessful, limited open reduction was performed, followed by Kirschner wire intramedullary fixation of the radius and ulna. The fracture healing was evaluated by X-ray after operation, and the curative effect was evaluated by Anderson forearm function score standard.@*RESULTS@#The wound healed well after operation, 2 cases had clinical manifestations of needle tail irritation after operation, and the symptoms disappeared after removing the internal fixation. The average follow-up time was(7.68±3.50) months (3 to 14 months). X-ray showed that all fracture healing in follow-up, Anderson forearm function score showed excellent in 16 cases, good in 2 cases and fair in 1 case at the final follow-up.@*CONCLUSION@#Children with fractures in plateau areas often have delayed medical treatment, lack of medical conditions and insufficient compliance. Based on these characteristics, Kirschner wire intramedullary fixation for the treatment of children's double forearm fractures has the advantages of small injury and rapid recovery. It is a kind of operation method that can be popularized.

Development and clinical application of a new reduction device for the treatment of tibial plateau fracture under arthroscopic monitoring / 中国骨伤

OBJECTIVE@#To develop a reduction device for the arthroscopy-assisted treatment of tibial plateau fracture and explore its clinical efficacy.@*METHODS@#From May 2018 to September 2019, 21 patients with tibial plateau fracture were treated, including 17 males and 4 females. Their ages ranged from 18 to 55 years old with an average of (38.6±8.7) years old. There were 5 cases of Schatzker typeⅡand 16 cases of Schatzker type Ⅲ. The self-designed reductor combined with arthroscope was used for auxiliary reduction and fixation(minimally invasive percutaneous plate osteosynthesis). The efficacy was analyzed by observing the operation time, blood loss, fracture healing time and knee function(HSS and IKDC scoring criteria).@*RESULTS@#All the 21 patients were followed up for 8 to 24 with an average of(14.0±3.1) months. The operative time ranged from 70 to 95 min with an average of(81.7±7.6)min, incision length ranged from 4 to 7 cm with an average of(5.3±0.9) cm, intraoperative blood loss ranged from 20 to 50 ml with an average of(35.3±5.2) ml, postoperative weight-bearing time ranged from 30 to 50 d with an average of(35.1±9.2) d, fracture healing time ranged from 65 to 90 d with an average of(75.0±4.4) d, and complications were 0 cases, respectively. The fracture was well healed and no screw plate fracture was observed. The knee function scores of HSS and IKDC 18 months after operation were significantly higher than those before operation(P<0.05).@*CONCLUSION@#The custom-made reduction tool for the arthroscopic management of tibial plateau fracture is reasonable in design and simple in operation. The specific reduction tool could effectively reduce the fracture, and shorten the fixation time with minimally invasive procedure.

Treatment analysis of complex Schatzker type Ⅳ tibial plateau fractures / 中国骨伤

OBJECTIVE@#To explore treatment strategy for complex Schatzker Ⅳ tibial plateau fracture.@*METHODS@#Forty-one patients with complex Schatzker type Ⅳ tibial plateau fractures were treated from January 2016 to January 2021, including 28 males and 13 females, aged from 19 to 65 years old with an average of (35.3±19.8) years old. Individualized treatment plan was developed according to preoperative imaging characteristics, medial surgical approach was mainly combined with other auxiliary incisions. Posteromedial inverted L approach was used in 18 patients, posteromedial approach and anterolateral extended approach in 19 patients, and posteromedial approach with anterolateral and lateral condylar osteotomy in 4 patients. Articular surface and facture healing were observed, range of knee joint motion was measured at 12 months after opertaion, and function of knee joint was evaluated by Lysholm scoring system.@*RESULTS@#Forty-one patients were followed up for 12 to 26 months with an average of (13.3±6.8) months. Twenty-nine patients and 10 patients were obtained complete fracture healing at 6 and 12 months after operation respectively, and fracture healing time was 4 to 13 months with an average of (5.0±3.7) months. Two patients occurred posterior medial internal fixation failure and varus deformity of knee joint, and the fracture healed and varus deformity was corrected after the second operation. Range of knee joint motion was (118±29) °, and Lysholm score was(83.0±16.0) points.@*CONCLUSION@#Individualized treatment should be reasonably selected for complex Schatzker Ⅳ tibial plateau fractures, the characteristics of lateral plateau fractures are an important reference for selecting surgical approaches, the effective fixation of posteromedial bone blocks should be pay full attention, and the overall treatment results are satisfied.

Osteotomy of non-core weight-bearing area of the lateral tibial plateau, reduction, and internal fixation in treatment of tibial plateau fractures involving posterolateral column collapse / 中国修复重建外科杂志

OBJECTIVE@#To investigate the effectiveness of osteotomy of non-core weight-bearing area of the lateral tibial plateau, reduction, and internal fixation in the treatment of tibial plateau fractures involving posterolateral column collapse.@*METHODS@#A clinical data of 23 patients with tibial plateau fractures involving posterolateral column collapse, who had undergone osteotomy of non-core weight-bearing area of the lateral tibial plateau, reduction, and internal fixation between January 2015 and June 2021, was retrospectively analyzed. There were 14 males and 9 females with an average age of 42.6 years ranging from 26 to 62 years. The causes of injury included traffic accident in 16 cases, falling from height in 5 cases, and other injuries in 2 cases. According to Schatzker classification, there were 15 cases of type Ⅴ and 8 cases of type Ⅵ. The time from injury to operation was 4-8 days with an average of 5.9 days. The operation time, intraoperative blood loss, fracture healing time, and complications were recorded. The depth of articular surface collapse of posterolateral column and posterior inclination angle (PSA) of the tibial plateau were compared before operation and at 2 days and 6 months after operation; fracture reduction of tibial plateau fracture was evaluated by Rasmussen anatomic score. The recovery of knee function was evaluated by Hospital for Special Surgery (HSS) score at 2 days and 6 months after operation.@*RESULTS@#All 23 patients were completed the operation successfully. The operation time was 120-195 minutes, with an average of 152.8 minutes; the intraoperative blood loss was 50-175 mL, with an average of 109.5 mL. All patients were followed up 12-24 months, with an average of 16.7 months. One patient had superficial wound infection after operation, and the incision healed after dressing change; primary healing of incision of other patients was obtained. The fracture healing time was 12-18 weeks, with an average of 13.7 weeks. No failure of internal fixation, varus and valgus deformity of the knee joint, and instability of the knee joint was found at last follow-up. One patient developed joint stiffness and the range of motion of the knee joint was 10°-100°; the range of motion of the knee joint of other patients was 0°-125°. At 2 days and 6 months after operation, the depth of articular surface collapse of posterolateral column, PSA, and Rasmussen anatomic scores significantly improved when compared with those before operation ( P<0.05). There was no significant difference between the two postoperative time points ( P>0.05). The HSS score at 6 months after operation was significantly higher than that at 2 days after operation ( P<0.05).@*CONCLUSION@#For tibial plateau fractures involving posterolateral column collapse, reduction and internal fixation through osteotomy of non-core weight-bearing area of the lateral tibial plateau has the advantages of fully expose the posterolateral column fragment, good articular surface reduction, sufficient bone grafting, and fewer postoperative complications. It is beneficial to restore knee joint function and can be widely used in clinic.

Risk factors for unplanned readmission in patients with acute myocardial infarction in Plateau Area / 公共卫生与预防医学

Objective To explore the risk factors of unplanned readmission in patients with acute myocardial infarction in plateau area. Methods The convenience sampling method was used to select 220 patients with acute myocardial infarction in the hospital's internal medicine department from January 2020 to May 2021. The patients were divided into two groups according to whether they had unplanned readmission within one year, 79 patients were included in readmission group, and 141 patients without unplanned readmission were included in non-readmission group. Clinical data of the 220 patients with acute myocardial infarction in plateau area were collected by reviewing electronic medical records, and laboratory examination and angiography examination were performed 1 day before discharge. Univariate and multivariate logistic regression analysis were carried out, and ROC curve risk prediction model was established. Results There were statistically significant differences in age, history of myocardial infarction, history of PCI, history of stroke, blood calcium, and Kilip cardiac function between the two groups (P < 0.05). Logistic regression analysis showed that age ≥60 years old, history of myocardial infarction, history of PCI, history of stroke, blood calcium and Kilip cardiac function grading were positively correlated with unscheduled readmission (P < 0.05). The ROC curve was drawn with the occurrence of unplanned readmission as the state variable. The AUC area was 0.801, the predictive sensitivity was 88.94%, and the specificity was 57.92%. Conclusion Unplanned readmission of AMI patients in plateau areas is related to multiple factors. It is necessary to identify high-risk groups as early as possible in combination with risk factors and develop individualized intervention measures.

Effect of different hypoxic and hypobaric interventions on blood gas and erythrocyte-related indicators in rats / 浙江大学学报·医学版

OBJECTIVES@#To explore the effects of hypoxic and hypobaric conditions on blood gas and erythrocyte-related indicators in rats.@*METHODS@#SD male rats were exposed to low-pressure hypoxic conditions simulating an altitude of 6500 m in a small or a large experimental cabin. Abdominal aortic blood samples were collected and blood gas indicators, red blood cells (RBCs) count, and hemoglobin (Hb) content were measured. The effects of exposure to different hypoxia times, different hypoxia modes, normal oxygen recovery after hypoxia, and re-hypoxia after hypoxia preconditioning on blood gas indicators, RBCs count and Hb content were investigated.@*RESULTS@#The effect of blood gas indicators was correlated with the length of exposure time of hypoxia and the reoxygenation after leaving the cabin. Hypoxia caused acid-base imbalance and its severity was associated with the duration of hypoxia; hypoxia also led to an increase in RBCs count and Hb content, and the increase was also related to the time exposed to hypoxia. The effects of reoxygenation on acid-base imbalance in rats caged in a small animal cabin were more severe that those in a large experimental cabin. Acetazolamide alleviated the effects of reoxygenation after leaving the cabin. Different hypoxia modes and administration of acetazolamide had little effect on RBCs count and Hb content. Normal oxygen recovery can alleviate the reoxygenation and acid-base imbalance of hypoxic rats after leaving the cabin and improve the increase in red blood cell and hemoglobin content caused by hypoxia. The improvement of hypoxia preconditioning on post hypoxia reoxygenation is not significant, but it can alleviate the acid-base imbalance caused by hypoxia in rats and to some extent improve the increase in red blood cell and hemoglobin content caused by hypoxia.@*CONCLUSIONS@#Due to excessive ventilation and elevated RBCs count and Hb content after hypoxia reoxygenation, oxygen partial pressure and other oxygenation indicators in hypoxic rats are prone to become abnormal, while blood gas acid-base balance indicators are relatively stable, which are more suitable for evaluating the degree of hypoxia injury and related pharmacological effects in rats.

Electric scooter injuries: Incidence and injury patterns at a level I trauma center / 中华创伤杂志(英文版)

PURPOSE@#Electric scooters (e-scooters) have become an increasingly popular mode of public transportation in recent years. As the incidence of related injuries rises, it is important to understand specific fracture patterns unique to e-scooters and electric bikes (e-bikes) to help guide management. The purpose of this study was to review the prevalence and describe specific fracture patterns of e-scooter and e-bike related injuries at the busiest level 1 trauma center in the borough of Manhattan.@*METHODS@#Chart review to determine mechanism of injury was performed on all patients for whom an orthopedic consult was requested from 1/1/2021 to 12/31/2021. All patients whose injuries were sustained due to an e-scooter or e-bike were further reviewed for demographics, injury characteristics including fracture pattern, and definitive injury management. Any patients who had an orthopedic consult placed for a reason other than an acute injury were excluded. Descriptive statistics are reported as frequency (percentage) for categorical variables and means for continuous variables.@*RESULTS@#Of the 1815 orthopedic consults requested, 1357 (74.8%) were for acute injury management. Of those with acute injuries, 119 (8.8%) sustained 136 e-scooter or e-bike related injuries. There were 92 (77.3%) males at an average age of (33.8 ± 15.7) years. Approximately one-fifth of all patients presented in June 2021 (26, 21.8%). There was a 9.2% rate of open fractures. The 136 injuries were evenly split between the upper and lower extremities, with 57 (47.9%) upper extremity, 57 (47.9%) lower extremity injuries, and 5 (4.2%) concomitant upper and lower extremity injuries. The most common fracture patterns were ankle fractures (16, 11.7%), followed by tibial shaft (14, 10.2%), tibial plateau (13, 9.5%), and radial head fractures (11, 8.0%). There was a 33.3% incidence of associated posterior malleolar fractures in the spiral tibial shaft fractures, 31.0% of posterior malleolar involvement and 18.8% of isolated vertical medial malleolar fractures in the ankle fractures, and 61.5% of posterior comminution in the tibial plateau fractures.@*CONCLUSION@#E-scooter and e-bike related injuries have a high incidence of tibial shaft fractures, ankle fractures, tibial plateau fractures, and radial head fractures. There should be a high index of suspicion for posterior and medial involvement in lower extremity fractures sustained due to e-scooter or e-bikes. Identifying specific fracture patterns seen in e-scooter and e-bike related mechanisms will help guide management of these injuries.

Clinical study on the subchondral screw compression technique assisted reduction of residual or secondary collapse of lateral tibial plateau / 中国修复重建外科杂志

OBJECTIVE@#To explore the reduction and support effect of the subchondral screw compression technique for residual or secondary collapse of the lateral tibial plateau during operation.@*METHODS@#Between January 2020 and June 2021, 11 patients with residual or secondary collapse of the lateral tibial plateau during operation were treated with the subchondral screw compression technique. There were 6 males and 5 females, aged 52.3 years old (range, 27-64 years). The fractures were caused by traffic accident in 10 cases and falling from height in 1 case and located at the left knee in 6 cases and the right knee in 5 cases. According to Schatzker classification, there were 5 cases of type Ⅱ fractures, 4 cases of type Ⅲ fractures, and 2 cases of type Ⅴfractures. According to the three columns classification, there were 5 cases of lateral column, 4 cases of lateral column and posterior column, and 2 cases of three columns. The time from injury to operation was 4.5 days (range, 3-7 days). During the follow-up, X-ray films were obtained and the Rasmussen standard was used to evaluate the quality of fracture reduction, meanwhile fracture healing was observed. The medial proximal tibial angle (mPTA), posterior tibial slope angle (pTSA), and articular surface collapse were measured at immediate and 12 months after operation. The knee joint range of motion was evaluated at last follow-up, and the knee joint function was evaluated using the Hospital for Special Surgery (HSS) score.@*RESULTS@#All operations were successfully completed, with a mean operation time of 71.4 minutes (range, 55-120 minutes), and a mean hospital stay of 8.0 days (range, 5-13 days). The incisions all healed by first intention, without complications such as infection, flap necrosis, or vascular and nerve injury. All patients were followed up 16.5 months on average (range, 12-24 months). X-ray films showed that the fracture reduction score was 14-18 (mean, 16.7) according to Rasmussen score criteria; and 5 cases were rated as excellent and 6 as good. All fractures healed clinically with a mean clinical healing time of 14.9 weeks (range, 12-16 weeks), and there was no complications such as plate or screw loosening. At 12 months after operation, the mPTA and pTSA were (87.5±1.7)° and (6.2±3.1)°, respectively; there was no significant difference when compared to the values at immediate after operation [(87.6±1.8)° and (6.5±3.1)°] ( P>0.05). The articular surface of the tibial plateaus was effectively supported, and it collapsed again by 0-1.0 mm at 12 months, with an average of 0.4 mm. At last follow-up, the knee joint range of motion was 115°-135° (mean, 126.8°) and the HSS score for knee joint function was 87-98 (mean, 93.9). Five patients underwent secondary operation to remove the internal fixator at 12-18 months after operation.@*CONCLUSION@#The subchondral screw compression technique is helpful for the reduction of residual or secondary collapse of the lateral tibial plateau during operation, and can provide good support for osteochondral blocks.

Efficacy and safety of multiple-dose intravenous tranexamic acid for reducing blood loss in complex tibial plateau fractures: A prospective randomized controlled trial / 中国修复重建外科杂志

OBJECTIVE@#To investigate the efficacy and safety of multiple-dose intravenous tranexamic acid (TXA) for reducing blood loss in complex tibial plateau fractures with open reduction internal fixation by a prospective randomized controlled trial.@*METHODS@#A study was conducted on patients with Schatzker type Ⅳ-Ⅵ tibial plateau fractures admitted between August 2020 and December 2022. Among them, 88 patients met the selection criteria and were included in the study. They were randomly allocated into 3 groups, the control group (28 cases), single-dose TXA group (31 cases), and multiple-dose TXA group (29 cases), using a random number table method. There was no significant difference ( P>0.05) in terms of age, gender, body mass index, the Schatzker type and side of fracture, laboratory examinations [hemoglobin (Hb), activated partial thromboplastin time (APTT), prothrombin time (PT), fibrinogen (Fib), international normalized ratio (INR), D-dimer, and interleukin 6 (IL-6)], and preoperative blood volume. The control group received intravenous infusion of 100 mL saline at 15 minutes before operation and 3, 6, and 24 hours after the first administration. The single-dose TXA group received intravenous infusion of 1 g TXA (dissolved in 100 mL saline) at 15 minutes before operation, followed by an equal amount of saline at each time point after the first administration. The multiple-dose TXA group received intravenous infusion of 1 g TXA (dissolved in 100 mL saline) at each time point. The relevant indicators were recorded and compared between groups to evaluate the effectiveness and safety of TXA, including hospital stays, operation time, occurrence of infection; the occurrence of lower extremity deep vein thrombosis, intermuscular vein thrombosis, and pulmonary embolism at 1 week after operation; the lowest postoperative Hb value and Hb reduction rate, the difference (change value) between pre- and post-operative APTT, PT, Fib, and INR; D-dimer and IL-6 at 24 and 72 hours after operation; total blood loss, intraoperative blood loss, hidden blood loss, drainage flow during 48 hours after operation, and postoperative blood transfusion.@*RESULTS@#① TXA efficacy evaluation: the lowest Hb value in the control group was significantly lower than that in the other two groups ( P<0.05), and there was no significant difference between the single- and multiple-dose TXA groups ( P>0.05). The Hb reduction rate, total blood loss, intraoperative blood loss, drainage flow during 48 hours after operation, and hidden blood loss showed a gradual decrease trend in the control group, single-dose TXA group, and multiple-dose TXA group. And differences were significant ( P<0.05) in the Hb reduction rate and drainage flow during 48 hours after operation between groups, and the total blood loss and hidden blood loss between control group and other two groups. ② TXA safety evaluation: no lower extremity deep vein thrombosis or pulmonary embolism occurred in the three groups after operation, but 3, 4, and 2 cases of intermuscular vein thrombosis occurred in the control group, single-dose TXA group, and multiple-dose TXA group, respectively, and the differences in the incidences between groups were not significant ( P>0.05). There was no significant difference in the operation time between groups ( P>0.05). But the length of hospital stay was significantly longer in the control group than in the other groups ( P<0.05); there was no significant difference between the single- and multiple-dose TXA groups ( P>0.05). ③ Effect of TXA on blood coagulation and inflammatory response: the incisions of the 3 groups healed by first intention, and no infections occurred. The differences in the changes of APTT, PT, Fib, and INR between groups were not significant ( P>0.05). The D-dimer and IL-6 in the three groups showed a trend of first increasing and then decreasing over time, and there was a significant difference between different time points in the three groups ( P<0.05). At 24 and 72 hours after operation, there was no significant difference in D-dimer between groups ( P>0.05), while there was a significant difference in IL-6 between groups ( P<0.05).@*CONCLUSION@#Multiple intravenous applications of TXA can reduce perioperative blood loss and shorten hospital stays in patients undergoing open reduction and internal fixation of complex tibial plateau fractures, provide additional fibrinolysis control and ameliorate postoperative inflammatory response.

Correlation study on the influencing factors of semitendinosus insertion location / 中国修复重建外科杂志

OBJECTIVE@#To investigate the relationship between the vertical distance from semitendinosus insertion to tibial plateau (S-T) and the physical characteristics of patients, in order to provide reference for incision design to expose the semitendinosus insertion.@*METHODS@#The patients with ligament injury who underwent primary anterior cruciate ligament reconstruction between January 2022 and December 2022 were selected as the research subjects. The patients' baseline data were collected, including age, gender, height, and body mass. During reconstruction operation, the S-T was measured. Considering the S-T as the dependent variable and baseline data as the independent variable, multiple linear regression analysis was used to establish a regression equation to determine the possible influencing factors of semitendinosus insertion location.@*RESULTS@#According to the selection standard, a total of 214 patients were enrolled, including 156 males and 58 females, aged (27±9) years (14-49 years), with a height of (174.7±6.8) cm (range, 160-196 cm) and a body mass of (73.43±12.35) kg (range, 53-105 kg). The S-T was (56.36±3.61) mm (range, 47-67 mm). The multiple linear regression analysis results showed that the height was positively correlated with S-T (β=0.407, SE=0.055, t=7.543, P<0.001); the regression equation was S-T=-14.701+0.407×height, R2=0.690.@*CONCLUSION@#There was a linear relationship between the height and semitendinosus insertion. The location of semitendinosus insertion estimated by the formula (S-T=-14.701+0.407×height) is reasonable, which provides a theoretical basis for rapid, accurate, and safe location of semitendinosus insertion and design of surgical incision in clinic.

Exploring the links between gut microbiome changes and irritable bowel syndrome in Han populations in the Tibetan Plateau / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

The gut microbiome shows changes under a plateau environment, while the disbalance of intestinal microbiota plays an important role in the pathogenesis of irritable bowel syndrome (IBS); however, the relationship between the two remains unexplored. In this work, we followed up a healthy cohort for up to a year before and after living in a plateau environment and performed 16S ribosomal RNA (rRNA) sequencing analysis of their fecal samples. Through evaluating the participants' clinical symptoms, combined with an IBS questionnaire, we screened the IBS sub-population in our cohort. The sequencing results showed that a high-altitude environment could lead to changes in the diversity and composition of gut flora. In addition, we found that the longer the time volunteers spent in the plateau environment, the more similar their gut microbiota composition and abundance became compared to those before entering the plateau, and IBS symptoms were significantly alleviated. Therefore, we speculated that the plateau may be a special environment that induces IBS. The taxonomic units g_Alistipes, g_Oscillospira, and s_Ruminococcus_torques, which had been proved to play important roles in IBS pathogenesis, were also abundant in the IBS cohort at high altitudes. Overall, the disbalance of gut microbiota induced by the plateau environment contributed to the high frequency of IBS and the psychosocial abnormalities associated with IBS. Our results prompt further research to elucidate the relevant mechanism.