Abordaje terapéutico del colapso transversal del maxilar superior con microimplantes (TAD´s) / Therapeutic approach of transverse maxillary collapse with microimplants (TAD's)

Introducción. La atresia o estrechez del maxilar superior es una patología de origen multifactorial que genera un colapso transversal, el mismo e implica la carencia de espacio necesario para la disposición correcta de las piezas dentales. Objetivo. El presente artículo está enmarcado en una revisión narrativa de la literatura, con el objetivo de describir el abordaje terapéutico del colapso transversal del maxilar superior con microimplantes (TAD´s), determinando los efectos esqueléticos y dentoalveolares en el maxilar superior, así como las ventajas y desventajas del tratamiento. Método. La búsqueda de artículos se realizó a través de mediante las plataformas de: Scielo, PubMed, Google Académico y Medline. Se seleccionaron 21 artículos cuyos textos completos fueron descargados para examinarlos a detalle y verificar que cumplieran con todos los criterios de inclusión, de los cuales se obtuvieron 16 artículos para elaborar esta revisión narrativa. Conclusiones. El abordaje terapéutico del colapso transversal se produce por medio de la expansión rápida del maxilar (ERM) o disyunción maxilar, en pacientes jóvenes en crecimiento; y en los pacientes adultos se suele emplear un tratamiento con técnica MARPE con microimplantes (TAD´s). El principal efecto esquelético es la apertura de la sutura maxilar que varía de 2 a 10 mm, muchos autores coinciden en que el manejo del colapso transversal del maxilar superior con microimplantes no genera efectos dentoalveolares negativos, al contrario, tiene ventajas biomecánicas debido al anclaje con el hueso, reduciendo el riesgo de movimiento dentales indeseados y permitiendo un control del crecimiento vertical.

Introduction. The atresia or narrowness of the upper jaw is a pathology of multifactorial origin that generates a transverse collapse, it implies the lack of space necessary for the correct arrangement of the dental pieces. Objective. This article is framed in a narrative review of the literature, with the aim of describing the therapeutic approach of transverse maxillary collapse with microimplants (TAD's), determining the skeletal and dentoalveolar effects in the maxilla, as well as the advantages and disadvantages of treatment. Method. The search for articles was carried out through the following platforms: Scielo, PubMed, Google Scholar and Medline. 21 articles whose full texts were downloaded were selected to examine them in detail and verify that they met all the inclusion criteria, of which 18 articles were obtained to prepare this narrative review. Conclusions. The therapeutic approach to transverse collapse occurs through rapid maxillary expansion (RME) or maxillary disjunction, in young growing patients; and in adult patients, treatment with the MARPE technique with microimplants (TAD's) is usually used. The main skeletal effect is the opening of the maxillary suture, which varies from 2 to 10 mm. Many authors agree that the management of the transverse collapse of the maxilla with microimplants does not generate negative dentoalveolar effects, on the contrary, it has biomechanical advantages due to the anchorage with the bone, reducing the risk of unwanted dental movement and allowing control of vertical growth.

Comparative Evaluation of Duration of Extraction Space Closure and Degree of Root Resorption with Conventional and Self-Ligation Brackets

Introduction: Determination of difference between conventional and passive self?ligating brackets (SLBs) in respect of extraction space closure, patient perception and root resorption. Material and Methods: Eighty patients were divided into four groups of 20 each with age?sex?matched control using a simple randomisation technique and allocation concealment with a closed opaque envelope method. Group 1 consisted of conventional brackets with Connecticut New Archwire (CNA) wire mushroom loop, group 2 consisted of conventional brackets with TAD (AbsoAnchor, Korea) supported retraction, group 3 consisted of passive SLB with CNA archwires (Libral Traders, India) mushroom loop and group 4 consisted of passive SLB brackets with TAD (AbsoAnchor, Korea) supported retraction. The rate of retraction, root resorption and patient satisfaction were assessed. All conventional brackets (Orthox, USA) and passive SLBs (CaptainOrtho, India) had 0.018 Roth prescriptions with a slot size of 0.018 × 0.025. Results: Retraction was the fastest in group 2 with a mean of 1.266 ± 0.14 mm/4 week and a duration of 23.40 weeks. Similarly, group 4 showed the most sluggish movement with a mean of 1.182 ± 0.80 mm/4 weeks with a total duration of 25 weeks; howeverdifferencesce among groups were not statistically significant (P = 0.470). Conclusion: SLBs have advantage of better patient comfort, less pain and reduced chairside time. Though the present study found increased treatment duration with SLB along with friction mechanics, refuting the previous claims of reduced friction with SLBs, however, the difference was not statistically significant and results have to be extrapolated with caution and experience considering other advantages of SLBs.

Radiation-induced Hierarchical Topologically Associated Domain Change and Its Role in Cellular Responses to Radiation / 中国生物化学与分子生物学报

The three-dimensional (3D) genome organization plays an important role in gene regulation. As a basic functional unit of the genome, topologically associated domain (TAD) regulates multiplebiological processes such as gene expression and DNA replication and plays a role in radiation-inducedDNA damage repair. Recent studies showed that TAD is not a completely independent domain butcontains hierarchical internal domains, which could be a new mechanism of gene regulation. To explorethe role of hierarchical TAD in cellular responses to radiation, we apply the OnTAD algorithm, anoptimized nested TAD caller from Hi-C data, to identify hierarchical TAD in 26 Hi-C data from Geneexpression omnibus (GEO) database. These data were from irradiated fibroblasts, lymphoblasts andfibroblasts deficient in the ataxia telangiectasia mutated (ATM) gene with 5 Gy X-ray. We observe thatX-ray can regularly affect the hierarchy of TAD in which high-level TAD is prone to change and low-levelTAD is more conservative. We propose that radiation-induced TAD hierarchy change can regulate cellularresponses to radiation by regulating gene expression, and ATM is a necessary factor for radiation-inducedTAD hierarchy change and recovery. This study provides new insights into the role of the 3D genome inradiation-induced cellular responses from the perspective of hierarchical TAD structures.

3D organization profiling of human hepatocellular carcinoma cell line PLC/PRF/5 in comparison with normal human liver cell line L02 by in situ Hi-C / 生物工程学报

Genetic and epigenetic alterations accumulate in the process of hepatocellular carcinogenesis, but the role of genomic spatial organization in HCC is still unknown. Here, we performed in situ Hi-C in HCC cell line PLC/PRF/5 compared with normal liver cell line L02, together with RNA-seq and ChIP-seq of SMC3/CTCF/H3K27ac. The results indicate that there were significant compartment switching, TAD shifting and loop pattern altering in PLC/PRF/5. These spatial changes are correlated with abnormal gene expression and more opening promoter regions of the HCC cell line. Thus, the 3D genome organization alterations in PLC/PRF/5 are important in epigenetic mechanisms of HCC tumorigenesis.

La distancia punta-apex: actualidad, vigencia e innovaciones / The tip-apex distance: the current, validity and innovations

Introducción: El tratamiento quirúrgico de las fracturas intertrocantericas presenta complicaciones postquirúrgicas múltiples debido a varios factores, el índice punta-ápex o "TAD" es uno de los principales predictores del desanclaje del tornillo femoral o "cut out". Objetivo: Realizar una revisión bibliográfica del "TAD" en los estudios científicos más actuales. Materiales y métodos: Estudio descriptivo de búsqueda bibliografíca en páginas científicas como Scielo, Elsevier, Pubmed, Medline y bibliotecas virtuales nacionales e internacionales. Resultados: Las fracturas intertrocantericas representan el 50% de todas las fracturas del fémur proximal, mayor incidencia en mujeres (2:1 hasta 8:1) y personas mayores de 65 años, las complicaciones postquirúrgicas representan el 17%, el desanclaje de tornillo o "cut out" se describe como la complicación más común. El "TAD" es usado desde 1995; la migración del tornillo deslizante en la cabeza femoral se observa inclusive en pacientes con TAD menor de 25 mm, debido a la implicancia de factores (asociados al implante, mal posicionamiento del tornillo deslizante y mala calidad ósea), dando un umbral óptimo del TAD más bajo (<20 mm) que el corte tradicional(<25 mm); por cada milímetro que aumenta el TAD, el riesgo de corte aumenta aproximadamente 1.1. El TAD presenta una especificidad significativamente mayor que el CalTAD y TAD + CalTAD (59.1 vs 49.2%, p <0.001; 59.1 vs 54.1%, p <0,001). Conclusiones: El "TAD", sigue siendo el mayor predictor de "cut out" en la actualidad inclusive por encima de los nuevos predictores. (AU)

Introduction: Surgical treatment of intertrochanteric fractures involves multiple post-surgical complications due to several factors. The tip-apex distance or "TAD" is one of the main predictors of femoral screw displacement or "cutout". Objective: perform a bibliographic review of the "TAD" in the most current scientific studies. Materials and methods: Descriptive study of bibliographic searches in scientific sites such as Scielo, Elsevier, Pubmed, Medline and national and international virtual libraries. Results: Intertrochanteric fractures account for 50% of all fractures of the proximal femur, higher incidence in women (2:1 to 8:1) and people over 65 years, post-surgical complications account for 17%, screw displacement or "cutout" is described as the most common complication. The TAD has been used since 1995; migration of the sliding screw in the femoral head is observed even in patients with a cut out of less than 25 mm, due to the implication of factors (associated with the implant, poor positioning of the sliding screw and poor bone quality), giving an optimal threshold of cut out lower (<20 mm) than the traditional cut out (<25 mm); for every millimeter that the cut out increases, the risk of cut out increases approximately 1.1. TAD has a significantly higher specificity than CalTAD y TAD + CalTAD (59.1 vs 49.2%, p <0.001; 59.1 vs 54.1%, p <0,001). Conclusions: The "TAD", is still the biggest predictor of "cut out" at present even above the new predictors. (AU)

Induction of thoracic aortic dissection: a mini-review of β-aminopropionitrile-related mouse models / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

Thoracic aortic dissection (TAD) is one of the most lethal aortic diseases due to its acute onset, rapid progress, and high rate of aortic rupture. The pathogenesis of TAD is not completely understood. In this mini-review, we introduce three emerging experimental mouse TAD models using β-aminopropionitrile (BAPN) alone, BAPN for a prolonged duration (four weeks) and then with added infusion of angiotensin II (AngII), or co-administration of BAPN and AngII chronically. We aim to provide insights into appropriate application of these three mouse models, thereby enhancing the understanding of the molecular mechanisms of TAD.

Induction of thoracic aortic dissection: a mini-review of β-aminopropionitrile-related mouse models / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

Thoracic aortic dissection (TAD) is one of the most lethal aortic diseases due to its acute onset, rapid progress, and high rate of aortic rupture. The pathogenesis of TAD is not completely understood. In this mini-review, we introduce three emerging experimental mouse TAD models using β-aminopropionitrile (BAPN) alone, BAPN for a prolonged duration (four weeks) and then with added infusion of angiotensin II (AngII), or co-administration of BAPN and AngII chronically. We aim to provide insights into appropriate application of these three mouse models, thereby enhancing the understanding of the molecular mechanisms of TAD.

Capacidad predictiva del apoyo a la autonomía en clases de educación física sobre el ejercicio físico / Predictive ability to support autonomy in classes of physical education on physical exercise

Resumen El objetivo de este estudio consistió en comprobar la capacidad de predicción del apoyo a la autonomía del docente en educación física, las necesidades psicológicas básicas y la motivación autodeterminada sobre la diversión, la importancia e intención hacia la educación física y la actividad física habitual. Se empleó una muestra de 718 estudiantes (346 chicos y 372 chicas) con edades comprendidas entre los 13 y los 19 años (M = 15,76, DT = 1,20). Se midió el apoyo a la autonomía, las necesidades psicológicas básicas, la motivación, la diversión, la importancia de la educación física, la intencionalidad para ser físicamente activo y la actividad física habitual. Se realizaron análisis estadísticos descriptivos y las correlaciones bivariadas de todas las variables objeto de estudio, análisis factoriales confirmatorios de los instrumentos y un análisis mediante el modelo de regresión estructural. Los resultados revelaron relaciones positivas y significativas entre todas las variables. Así, el apoyo a la autonomía predijo positivamente la satisfacción de las necesidades psicológicas básicas, y esta, a su vez, predijo la motivación autodeterminada, que predijo la diversión. La diversión predijo la importancia concedida a la educación física, y esta la intención de ser físicamente activo, que finalmente predijo la tasa de actividad física habitual. Los resultados contribuyen a optimizar el compromiso de los jóvenes hacia la actividad física, tanto dentro como fuera del aula.

Abstract The objective of this study was to check the prediction capacity of teacher's autonomy support in physical education, basic psychological needs and motivation self-determined about fun, importance and intention towards physical education and the usual physical activity. Participated a sample of 718 students (346 boys and 372 girls) with ages between 13 and 19 years (M = 15.76, SD = 1.20). Autonomy support perceived, basic psychological needs, motivation, fun, the importance of Physical education, intentionality to be physically active and habitual physical activity was measured. A descriptive statistical analyzes and bivariate correlations of all the variables object of study, confirmatory factor analyzes of the instruments and an analysis through the structural regression model was performed. The results revealed a positive and significant relationship between all the variables. Thus, the autonomy support positively predicted the satisfaction of the basic psychological needs, and this, in turn, predicted self-determined motivation, which predicted fun the fun, that predicted the importance given to physical education, and it the intention to be physically active, which finally predicted the usual physical activity rate. The results help to optimize the commitment of young people to physical activity, both inside and outside the classroom.

Complete genome sequence of the aerobically denitrifying thermophilic bacterium Chelatococcus daeguensis TAD1

ABSTRACT Chelatococcus daeguensis TAD1 is a themophilic bacterium isolated from a biotrickling filter used to treat NOx in Ruiming Power Plant, located in Guangzhou, China, which shows an excellent aerobic denitrification activity at high temperature. The complete genome sequence of this strain was reported in the present study. Genes related to the aerobic denitrification were identified through whole genome analysis. This work will facilitate the mechanism of aerobic denitrification and provide evidence for its potential application in the nitrogen removal.

Evaluation of the biofilm formation capacity of Pasteurella multocida strains isolated from cases of fowl cholera and swine lungs and its relationship with pathogenicity / Avaliação da capacidade de formação de biofilme por cepas de Pasteurella multocida isoladas de casos de cólera aviária e de pulmões de suínos e sua relação com a patogenicidade

Pasteurella multocida is a Gram-negative bacillus that causes economic losses due to the development of respiratory diseases in several animal species. Among the mechanisms of virulence, the formation of biofilms is an important factor for bacterial survival in hostile environments. Studies of biofilm formation by P. multocida are needed because P. multocida is an important pathogen involved in respiratory infections. However, in contrast to other microorganisms, few studies of biofilm formation have examined P. multocida. Studies comparing the pathogenicity of microbial strains as a function of their biofilm production capacity are also rare. Consequently, the aim of this study was to evaluate the biofilm formation capacity of 94 P. multocida strains isolated from cases of fowl cholera and from swine lungs on polystyrene plates. The associations of the biofilm formation capacity with the pathogenicity index (PI) in vivo and with the presence of four genes (screened by PCR) of the tad locus (tadB, tadD, tadE and tadG), described as adhesion markers, were also determined. Strains from both animal origins were able to form biofilms. However, most of the specimens (52.13%) were classified as weak producers, and more than 40% of the strains of P. multocida (40.42%) did not produce biofilms. There was no significant difference (p>0.05) in the degree of biofilm production between the two sources of isolation. Of the analyzed strains, 56.52% contained all four genes (tadB, tadD, tadE and tadG). The PI arithmetic mean of the strains classified as non-biofilm producers was significantly different (p<0.05) from the PI of moderate-producer strains. The PI of specimens classified as weak biofilm producers also differed significantly (p<0.05) from that of the moderate-producer strains. The results indicate that even though the P. multocida strains isolated from cases of fowl cholera and swine lungs formed biofilms on polystyrene surfaces, adhesion was usually weak. The genes tadB, tadD, tadE and tadG were not significantly associated (p>0.05) with the production of biofilms and with the origin of a given strain. Finally, low virulence strains may suggest a higher biofilm formation capacity on polystyrene plates.(AU)

Pasteurella multocida é um bacilo Gram negativo que ocasiona perdas econômicas, geralmente associadas a doenças respiratórias em diversas espécies animais. Entre os mecanismos de virulência existentes, a formação de biofilmes demonstra ser um importante fator para a proteção e para a sobrevivência bacteriana em ambientes hostis. Estudos relacionados à formação de biofilmes por P. multocida são necessários, uma vez que este é um importante patógeno envolvido em infecções respiratórias. Entretanto, ainda são poucos os estudos desenvolvidos nesta área, quando comparados com aqueles envolvendo outros microrganismos. Também são os raros os estudos que comparam a patogenicidade das cepas com a sua capacidade de produção de biofilme. Neste contexto, o objetivo deste estudo foi avaliar a capacidade de formação de biofilme em placas de poliestireno de 94 cepas de P. multocida isoladas de casos de cólera aviária e de pulmões de suínos, associando-se com o índice de patogenicidade (IP) in vivo e com a presença de quatro genes do locus tad (tadB, tadD, tadE e tadG), descritos como marcadores de adesão e pesquisados através de PCR. As cepas de ambas as origens foram capazes de formar biofilme. Contudo, a maioria dos exemplares (52,12%) foi classificada como fracamente produtora e mais de 40% das cepas de P. multocida (40,42%) não produziram biofilme. Não foi observada diferença estatística (p>0,05) quanto ao grau de produção de biofilme entre as duas origens de isolamento. 56,52% das cepas analisadas apresentaram os quatro genes (tadB, tadD, tadE e tadG) concomitantemente. O IP médio das cepas classificadas como não produtoras de biofilme apresentou diferença estatística (p˂0,05) em relação ao IP das cepas moderadamente produtoras. Os exemplares classificados como fracamente produtores de biofilme diferiram significativamente (p˂0,05) do grupo de cepas moderadamente produtoras. Os resultados obtidos indicaram que, apesar de as cepas de P. multocida isoladas de casos de cólera aviária e do pulmão de suínos apresentarem capacidade de formar biofilme em superfícies de poliestireno, a adesão ocorreu geralmente de forma fraca. Os genes tadB, tadD, tadE e tadG, pertencentes ao locus tad, não apresentaram associação significativa com a produção de biofilme e nem com a origem de isolamento da cepa. Por fim, observou-se que as cepas de menor patogenicidade apresentaram uma maior capacidade de formação de biofilme em placas de poliestireno.(AU)

Miniplacas como dispositivos de anclaje temporal (DAT) en la verticalización del segundo molar inferior impactado / Miniplates as temporary anchorage devices (TAD) for uprighting the impacted second mandibular molar

La impactación de los segundos molares inferiores permanentes es una patología con una incidencia del 0.03 or ciento a 0.04 por ciento del total de dientes retenidos, que en la mayoría de los casos debido a una posición impredecible del tercer molar, el resultado final es la exodoncia de ambas piezas dentarias.Dentro de los dispositivos de anclaje temporal, existen dos tipos, los minimplantes y las miniplacas. A través de este caso clínico se demuestra la eficiencia de las miniplacas en la verticalización de los segundos molares inferiores impactados sobre otras medidas terapéuticas debido a que su uso es un método predecible, rápido y seguro que no genera efectos secundarios indeseables. Además, estas miniplacas son colocadas a distancia de las piezas dentarias, por lo que no interfiere en los movimientos dentales.

Mandibular second molar impaction is a pathology with an incidence of 0.03% - 0.04% of the total of the impacted teeth due to animpredictible position of the third molar in most cases. As a consequence, where the final result is dental extraction of both teethThere are two types of temporary skeletal anchorage devices minimplants and miniplates. This case shows the miniplate efficiency in thesecond molar verticalization which is a predictible, fast and safe method without any side effects when compared with other treatments.In addition, miniplantes do not interfere with dental movements because they are placed far enough from the teeth.

Ocorrência de genes tad associados à formação de biofilme em isolados de Pasteurella multocida de pulmões de suínos com pneumonia / Occurrence of tad genes associated with biofilm formation in isolates of Pasteurella multocida from lungs of pigs with pneumonia

Nowadays pig intensive production systems increase microbial selection pressure favoring spread of respiratory diseases. The bacteria Pasteurella multocida is associated with various respiratory diseases in pigs under farming conditions causing high economic losses. In vitro biofilm formation has been described in P. multocida which role is described in tissue colonization, enhancing resistance to host defenses and antibiotics. The aims of this study were to analyze the occurrence of P. multocida in pig pneumonia and health lung microbiota, and occurrence of tad locus genes in these isolates. Seventy isolates of P. multocida were analyzed which sixty seven were from lungs with lesion and three from healthy lungs. Serotype A occurred mainly in lung lesion (85.71%), in healthy lung, instead, only serotype D was observed. Genes tadA, tadB, tadC, tadD, tadE, tadF and tadG were present in 89.55% isolates from lesion lung. Genes tadA, tadB and tadC were present in all isolates from healthy lungs but, tadD, tadE tadF and tadG were present in 0%, 33.3%, 33,3% and 66.6%, respectively. This work associated tadD, tadE and tadF gene positive isolates of P. multocida to lung pneumonic lesions.

Os atuais sistemas de criação intensiva de suínos aumentam a pressão de seleção microbiana propiciando a disseminação de doenças respiratórias. A bactéria Pasteurella multocida é associada a diversas patologias respiratórias em animais submetidos a esse tipo de criação, causando grandes perdas econômicas. A formação de biofilme foi descrita in vitro em P. multocida e fatores analisados indicaram a facilitação na colonização dos tecidos, aumentando a resistência às defesas do hospedeiro e aos antibióticos. Os objetivos deste trabalho foram analisar a ocorrência de P. multocida em pneumonias de suínos e na microbiota de pulmões sem lesão e a ocorrência dos genes do lócus tad nestes isolados. Foram analisados 70 isolados de P. multocida de pulmões, sendo sessenta e sete com lesão e três sem lesão. Isolados do sorotipo A ocorreram principalmente em pulmões com lesões (85,71%), enquanto em pulmões sem lesão observou-se somente o sorotipo D. Os genes tadA, tadB, tadC, tadD, tadE tadF e tadG estavam presentes em 89,55% dos isolados de pulmões com lesões. Os genes tadA, tadB e tadC estavam presentes em todos os isolados de pulmões sem lesão, porém os genes tadD, tadE, tadF e tadG estavam presentes em 0%, 33,3%, 33,3% e 66,6%, dos isolados sem lesão, respectivamente. Neste trabalho observou-se a associação da ocorrência dos genes tadD, tadE e tadF em isolados de P. multocida e a presença de lesões em pulmões.

Use of the Tip-Apex Distance in predicting Dynamic Hip Screw Cut Out in Intertrochanteric Fracture of the Femur in Asian Population

The objective of this study was to assess the rate of screw cut out in elderly patients treated with the dynamic hip screw and the relationship to the Tip Apex Distance (TAD). This is a retrospective radiological evaluation of 100 cases of elderly patients with intertrochanteric fracture treated with dynamic hip screw fixation surgically treated between 1998 and 2002. The incidence of screw cut out was assessed and correlation of risk of cut out with the TAD was assessed. The rate of screw cut out was 9.0% and the average length of time to screw cut out was 3.8 months (range, 1 to 6 months) postoperatively. The incidence of screw cut out increased significantly when the TAD was 20 mm or more. The screw cut out rates were 2.9%, 20.0%, 30.8%, 50% and 100% for TAD of 20-24 mm, 25-29 mm, 30-34 mm, 35-44 mm and > 45 mm respectively. Overall, a TAD of 20mm or more was associated with a statistically significant screw cut out risk in this Malaysian population.

Tratamiento de mordida abierta con dispositivos temporales de anclaje (DTA) / Open bite treatment with the use of TADS (Temporary anchorage device)

En este reporte de caso, un sistema de mini-implantes ortodóncicos vestibulares y palatinos, se utiliza para la intrusión de molares contribuyendo a la corrección de una mordida abierta dento-esquelética. Los aspectos tratados son: diagnóstico, tratamiento planteado, protocolo quirúrgico, consideraciones anatómicas, posibles complicaciones, curso del tratamiento, y presentación final del caso.

In this case report, a mini implant system that uses vestibular and palatal screws is presented as an excellent alternative for the treatment of and open bite case, it’s thru molar intrusion without any undesired transversal effect that the final results were achieved. The main topics treated are: diagnostic, treatment plan, surgical protocol, anatomic considerations, possible complications, curse of treatment, and final presentation of the case.

The association between the“Tip-Apex Distance”value and cut-out of the lag screw from the femoral head:a clinical retrospective study / 中华创伤骨科杂志

Objective To confirm the association between the“Tip-Apex Distance (TAD)”and cut-out of the lag screw from the femoral head.and to analyze other factors leading to the cut-out.Methods The complete radiographic and clinical data of 106 patients with femoral intertrochanteric fractures were available for this study. They were 65 men and 41 women,with an average age of 52.4 years (range,20 to 83 years).According to Evans classification.19 cases belonged to typeⅡ.25 to typeⅢ,32 to typeⅣ,29 to typeⅤ,and one to type R.The bone quality was classified by Singh rating system:44 cases were rated as typeⅥ.34 as typeⅤ,23 as typeⅣand five as typeⅢ.They were treated with open reduction and fixation with 135?dynamic hip screw (DHS).According to the finding of Baumgaertner that“TAD”beyond 25 mm would grcatly increase the risk of cut-out,the patients could be divided into two groups:59 cases with“TAD”less than 25 mm and 47 greater than 25 mm.Results The mean duration of follow-ups was 14.45 months (range,4.5 to 28.0 months).Of the 15 cases whose“TAD”was more than 30 mm,one had the cut-out.Of the seven cases whose“TAD”was more than 40 mm,two had the cut-out (P=0.000). The average age of the three patients was 78.7 years (range:75 to 83 years) and 27.1 years older than that of the 103 patients whose fracture healed (P=0.000).They belonged to the unstable intertrochanteric fracture of the femur (two to Evans type V and one to type R).The reduction was assessed as excellent in 43 cases,good in 47 cases,fair in nine cases (of whom one had the cut-out),poor in seven cases (of whom two had the cut-out). Conclusions The cut-out of the lag screw from the femoral head can be caused by age,fracture type and stability of reduction and“TAD”.The greater the“TAD”value,the greater possibility of cut-out.

The Value of the Tip - Apex Distance in Predicting Failure of Fixation of Intertrochanteric Fractures of the Hip / 대한정형외과학회잡지

Failure of fixation of intertrochanteric fractures that have been treated with a fixed-angle sliding hip-screw device is frequently related to the position of the lag screw in the femoral head. The purpose of this study is to introduce the concept of the tip-apex distance and to demonstrate its clinical usefulness as a predictor of cutout of the screw used for fixation of the intertrochanteric fractures of the hip. The tip-apex distance is the sum of the distance from the tip of the lag screw to the apex of femoral head on an anteroposterior radiograph and this distance on a lateral radiograph after controlling for magnification. To determine the value of tip-apex distance in the prediction of cutout of the lag screw, 67 intertrochanteric fractures that have been treated with a fixed-angle sliding hip screw device were studied. The minimum duration of follow-up was three months during which period all of the fractures either healed or had failure of the fixation. The average tip-apex distance was 21mm (range,22.8-65.8mm) for the successfully treated fractures compared with 35mm (range,8.4-65.8mm) for those in which the screw cutout. There was strong statistical relationship between an increasing tip-apex distance and the rate of cutout. An unstable fracture, a poor reduction were also associated with a significantly increased risk of failure due to cutout.