Intertrochanteric fractures,prevalent among older adults,pose significant clinical challenges due to high morbidity,mortality,and complication rates.Despite advancements in surgical methods and implant technology,one-...Intertrochanteric fractures,prevalent among older adults,pose significant clinical challenges due to high morbidity,mortality,and complication rates.Despite advancements in surgical methods and implant technology,one-year mortality remains between 20%and 30%,with up to 20%of survivors requiring revision surgery due to mechanical complications.Accurate fracture reduction and precise implant positioning are critical determinants of successful outcomes.This review synthesizes current literature on key radiographic parameters essential for evaluating fracture reduction quality and implant placement in intertrochanteric fracture fixation.Standardized intraoperative imaging techniques,such as correct anteroposterior and lateral fluoroscopic views,are fundamental for identifying malalignment.Important radiographic measures include the neck shaft angle,greater trochanter orthogonal line,anterior cortical line,and calcar displacement assessment.Reduction quality indices,notably the Baumgaertner and Chang Reduction Quality Criteria,provide reliable frameworks for predicting mechanical complications.Additionally,implant positioning parameters—including tip-apex distance,Calcar-referenced tip-apex distance,Cleveland zones,and Parker’s ratio index—are discussed as predictors of mechanical complications.Enhanced understanding and application of these radiographic criteria can improve surgical precision,reduce complications,and ultimately optimize patient outcomes in intertrochanteric fracture management.展开更多
Product variation reduction is critical to improve process efficiency and product quality, especially for multistage machining process（MMP）. However, due to the variation accumulation and propagation, it becomes qui...Product variation reduction is critical to improve process efficiency and product quality, especially for multistage machining process（MMP）. However, due to the variation accumulation and propagation, it becomes quite difficult to predict and reduce product variation for MMP. While the method of statistical process control can be used to control product quality, it is used mainly to monitor the process change rather than to analyze the cause of product variation. In this paper, based on a differential description of the contact kinematics of locators and part surfaces, and the geometric constraints equation defined by the locating scheme, an improved analytical variation propagation model for MMP is presented. In which the influence of both locator position and machining error on part quality is considered while, in traditional model, it usually focuses on datum error and fixture error. Coordinate transformation theory is used to reflect the generation and transmission laws of error in the establishment of the model. The concept of deviation matrix is heavily applied to establish an explicit mapping between the geometric deviation of part and the process error sources. In each machining stage, the part deviation is formulized as three separated components corresponding to three different kinds of error sources, which can be further applied to fault identification and design optimization for complicated machining process. An example part for MMP is given out to validate the effectiveness of the methodology. The experiment results show that the model prediction and the actual measurement match well. This paper provides a method to predict part deviation under the influence of fixture error, datum error and machining error, and it enriches the way of quality prediction for MMP.展开更多
The management and control system of improving quality, reducing cost and increasing efficiency aims to establish a corresponding incentive target system around the business tasks and development goals of the enterpri...The management and control system of improving quality, reducing cost and increasing efficiency aims to establish a corresponding incentive target system around the business tasks and development goals of the enterprise, guides the company all units and departments to strengthen the internal management, full of all aspects of mining efficiency potential, enhances the endogenous development of the enterprise power, so as to effectively cope with the market crisis, improve enterprise efficiency. With the end of the "golden decade" of thermal power generation enterprise market, the production and operation of thermal power generation enterprises are increasingly difficult. In order to effectively deal with the power market under the declining price environment, tap the internal efficiency potential of enterprises, and realize the loss and gain. Combined with the characteristics and actual situation of the enterprise, on the basis of summarizing previous experience, focusing on the high-quality development of the enterprise, highlighting value creation, making up for shortcomings, promoting reform and increasing benefits, the paper proposes to construct a management and control system to improve quality, reduce cost and increase efficiency.展开更多
基金Supported by the Orthopaedic Research Foundation of Western Australia,Freie Akademische Gesellschaft Baseland Swiss Orthopaedics.
文摘Intertrochanteric fractures,prevalent among older adults,pose significant clinical challenges due to high morbidity,mortality,and complication rates.Despite advancements in surgical methods and implant technology,one-year mortality remains between 20%and 30%,with up to 20%of survivors requiring revision surgery due to mechanical complications.Accurate fracture reduction and precise implant positioning are critical determinants of successful outcomes.This review synthesizes current literature on key radiographic parameters essential for evaluating fracture reduction quality and implant placement in intertrochanteric fracture fixation.Standardized intraoperative imaging techniques,such as correct anteroposterior and lateral fluoroscopic views,are fundamental for identifying malalignment.Important radiographic measures include the neck shaft angle,greater trochanter orthogonal line,anterior cortical line,and calcar displacement assessment.Reduction quality indices,notably the Baumgaertner and Chang Reduction Quality Criteria,provide reliable frameworks for predicting mechanical complications.Additionally,implant positioning parameters—including tip-apex distance,Calcar-referenced tip-apex distance,Cleveland zones,and Parker’s ratio index—are discussed as predictors of mechanical complications.Enhanced understanding and application of these radiographic criteria can improve surgical precision,reduce complications,and ultimately optimize patient outcomes in intertrochanteric fracture management.
基金Supported by National Natural Science Foundation of China(Grant Nos.51205286,51275348)
文摘Product variation reduction is critical to improve process efficiency and product quality, especially for multistage machining process（MMP）. However, due to the variation accumulation and propagation, it becomes quite difficult to predict and reduce product variation for MMP. While the method of statistical process control can be used to control product quality, it is used mainly to monitor the process change rather than to analyze the cause of product variation. In this paper, based on a differential description of the contact kinematics of locators and part surfaces, and the geometric constraints equation defined by the locating scheme, an improved analytical variation propagation model for MMP is presented. In which the influence of both locator position and machining error on part quality is considered while, in traditional model, it usually focuses on datum error and fixture error. Coordinate transformation theory is used to reflect the generation and transmission laws of error in the establishment of the model. The concept of deviation matrix is heavily applied to establish an explicit mapping between the geometric deviation of part and the process error sources. In each machining stage, the part deviation is formulized as three separated components corresponding to three different kinds of error sources, which can be further applied to fault identification and design optimization for complicated machining process. An example part for MMP is given out to validate the effectiveness of the methodology. The experiment results show that the model prediction and the actual measurement match well. This paper provides a method to predict part deviation under the influence of fixture error, datum error and machining error, and it enriches the way of quality prediction for MMP.
文摘The management and control system of improving quality, reducing cost and increasing efficiency aims to establish a corresponding incentive target system around the business tasks and development goals of the enterprise, guides the company all units and departments to strengthen the internal management, full of all aspects of mining efficiency potential, enhances the endogenous development of the enterprise power, so as to effectively cope with the market crisis, improve enterprise efficiency. With the end of the "golden decade" of thermal power generation enterprise market, the production and operation of thermal power generation enterprises are increasingly difficult. In order to effectively deal with the power market under the declining price environment, tap the internal efficiency potential of enterprises, and realize the loss and gain. Combined with the characteristics and actual situation of the enterprise, on the basis of summarizing previous experience, focusing on the high-quality development of the enterprise, highlighting value creation, making up for shortcomings, promoting reform and increasing benefits, the paper proposes to construct a management and control system to improve quality, reduce cost and increase efficiency.
