Assistance force-line of exosuit affects ankle multidimensional motion: a theoretical and experimental study.

BACKGROUND: The talocrural joint and the subtalar joint are the two major joints of the ankle-joint complex. The position and direction of the exosuit force line relative to these two joint axes can influence ankle motion. We aimed to understand the effects of different force-lines on ankle multidimensional motion. METHODS: In this article, three assistance force line schemes for ankle exosuits were proposed: perpendicular to the talocrural joint axis (PT), intersecting with the subtalar joint axis (IS), and parallel to the triceps surae (PTS). A theoretical model was proposed to calculate the exosuit's assistance moment. Seven participants completed four experimental tests of ankle plantarflexion, including three passive motions assisted by the PT, PTS and IS schemes, and one active motion without exosuit assistance (Active). RESULTS: The simulation results demonstrated that all three exosuits were able to produce significant moments of ankle plantarflexion. Among these, the PT scheme exhibited the highest moments in all dimensions, followed by the PTS and IS schemes. The experimental findings confirmed the effectiveness of all three exosuit schemes in assisting ankle plantarflexion. Additionally, as the assistive force lines approached the subtalar joint, there was a decrease in ankle motion assisted by the exosuits in non-plantarflexion directions, along with a reduction in the average distance of ankle angle curves relative to active ankle motion. Furthermore, the linear correlation coefficients between inversion and plantarflexion, adduction and plantarflexion, and adduction and inversion gradually converged toward active ankle plantarflexion motion. CONCLUSIONS: Our research indicates that the position of the exosuit force line to the subtalar joint has a significant impact on ankle inversion and adduction. Among all three schemes, the IS, which has the closest distance to the subtalar joint axes, has the greatest kinematic similarity to active ankle plantarflexion and might be a better choice for ankle assistance and rehabilitation.

[Study on the characteristics of biology force line of proximal femur based on structural topology optimization].

Internal fixator is usually adopted in the treatment of bone fractures. In order to achieve anatomical reduction and effective fixation of fractures, the placement of internal fixators should comply with the biology force line of the bone and adapt to the specific anatomical morphological characteristics of the cortical bone. In order to investigate the distribution characteristics and formation regularity of biology force line and cortical thickness of human bone, three-dimensional model of proximal femur is established by using three-dimensional reconstruction technique in this paper. The normal physiological stress distribution of proximal femur is obtained by finite element analysis under three kinds of behavior conditions: one-legged stance, abduction and adduction. The structural topology optimization method is applied to simulate the cortex of the proximal femur under the combined action of three kinds of behavior conditions, and the anatomic morphological characteristics of the proximal femur are compared. The distribution trend of biology force line of proximal femur and the characteristics of cortex are analyzed. The results show that the biology force lines of bone structure and the morphological characteristics of cortex depend on the load of human activities. The distribution trend of biology force line is related to the direction of trabecular bone and the ridge trend and firmness of cortex when bone is loaded physiologically. The proposed analytical method provides a solution to determine the biology force line of bone and the distribution characteristics of cortex. The conclusions obtained may guide the reasonable placement of internal fixator components of fracture.

[Finite element analysis of the impact of bone mass and volume of low-density area under tibial plateau on lower limb alignment].

Objective: To investigate the impact of the bone mass and volume of the low-density area under the tibial plateau on the lower limb force line by finite element analysis, offering mechanical evidence for preventing internal displacement of the lower limb force line in conjunction with knee varus in patients with knee osteoarthritis (KOA) and reducing bone mass under the tibial plateau. Methods: A healthy adult was selected as the study subject, and X-ray film and CT imaging data were acquired. Mimics 21.0 software was utilized to reconstruct the complete knee joint model and three models representing low-density areas under the tibial plateau with equal volume but varying shapes. These models were then imported into Solidworks 2023 software for assembly and verification. Five KOA finite element models with 22%, 33%, 44%, 55%, and 66% bone mass reduction in the low-density area under tibial plateau and 5 KOA finite element models with 81%, 90%, 100%, 110%, and 121% times of the low-density area model with 66% bone mass loss were constructed, respectively. Under physiological loading conditions of the human lower limb, the distal ends of the tibia and fibula were fully immobilized. An axial compressive load of 1 860 N, following the lower limb force line, was applied to the primary load-bearing area on the femoral head surface. The maximum stress within the tibial plateau, as well as the maximum displacements of the tibial cortical bone and tibial subchondral bone, were calculated and analyzed using the finite element analysis software Abaqus 2022. Subsequently, predictions regarding the alteration of the lower limb force line were made based on the analysis results. Results: The constructed KOA model accorded with the normal anatomical structure of lower limbs. Under the same boundary conditions and the same load, the maximum stress of the medial tibial plateau, the maximum displacement of the tibial cortical bone and the maximum displacement of the cancellous bone increased along with the gradual decrease of bone mass in the low-density area under the tibial plateau and the gradual increase in the volume of the low-density area under tibial plateau, with significant differences ( P<0.05). Conclusion: The existence of a low-density area under tibial plateau suggests a heightened likelihood of knee varus and inward movement of the lower limb force line. Both the volume and reduction in bone mass of the low-density area serve as critical initiating factors. This information can provide valuable guidance to clinicians in proactively preventing knee varus and averting its occurrence.

Implication of Changes in the Imaging Measurements after Mechanically Aligned Total Knee Arthroplasty.

OBJECTIVE: Imaging measurements allow assessment of the mechanical alignment before and after total knee arthroplasty (TKA). The changes in radiographic parameters in each period of time within 1 year after TKA has been poorly understood. The purpose of this study was to examine the timing and causes of imaging changes in lower extremity force lines after total knee arthroplasty with mechanical alignment. METHODS: A total of 93 mechanically-aligned TKA were radiographically examined before, 3 days, 3 months, and 1 year after surgery. Radiographic parameters included hip-knee angle (HKA), lateral distal femoral angle (LDFA), medial proximal tibial angle (MPTA), knee joint line orientation (KJLO), ankle joint line orientation (AJLO), the knee joint line relative to ankle joint line angle (KJLTA) and midpoints of the ankle distance (MAD). Paired t-test were used to analyze the changes of these imaging parameters, By establishing a simple tibial model, the time points of changes in the imaging parameters after TKA was determined, with an attempt to understand the post-TKA changes in these imaging parameters. RESULTS: Statistically significant differences were found between the preoperative data and the data measured 3 days after surgery in HKA, LDFA, MPTA, MAD, KJLTA, AJLO (P < 0.05) while KJLO exhibited no significant difference (P = 0.089). There existed significant differences between the data measured 3 days and the measurements taken 3 months after operation in HKA, MPTA, KJLTA, KJLO, AJLO (P < 0.05), whereas LDFA and MAD showed no significant difference (P > 0.05). Significant differences were revealed between the data measured 3 months and those collected 1 year after surgery in LDFA, MPTA, AJLO, KJLTA (P < 0.05) but HKA, KJLO, AJLO showed no significant differences (P > 0.05). The tibial model was made to look into the changes in postoperative imaging parameters. ΔMAD and postoperative AJLO were calculated to verify the model and hypothesis. CONCLUSIONS: Postoperative changes in radiographic parameters and tibial models showed that the lower extremities were in an unnatural state within 1 year after TKA. The changes in the lower extremities force line were the results of the gradual adaptation of the lower extremities to TKA and the lateral swing of the extremities (3°) after surgery. Imaging data 1 year after surgery should be taken into account in the explanation of post-TKA changes in lower limb force lines.

[Clinical application of Taylor spatial frame in adjustment of lower extremity force line of knee medial compartmental osteoarthritis].

OBJECTIVE: To explore the safety and effectiveness of Taylor spatial frame (TSF) in the treatment of medial compartmental osteoarthritis (MCOA) of the knee and the adjustment of the lower extremity force line at the same time. METHODS: The clinical data of 30 patients with MCOA who underwent high tibial osteotomy (HTO) between October 2016 and April 2017 were retrospectively analyzed. According to the different fixation methods, they were divided into external fixation group (TSF external fixation, 16 cases) and internal fixation group (locking steel plate internal fixation, 14 cases). There was no significant difference between the two groups in gender, age, side, disease duration, mechanical femur tibia angle (MFTA), and other general data ( P>0.05). The operation time and intraoperative blood loss of the two groups were recorded and compared; MFTA was used to evaluate the recovery of the lower extremity force line at last follow-up; Hospital for Special Surgery (HSS) score was used to evaluate the clinical effecacy before operation and at 2 weeks, 1 month, and 3 months after operation. RESULTS: The operation time and intraoperative blood loss of external fixation group were significantly less than those of internal fixation group ( P<0.05). All patients were followed up 9-16 months, with an average of 12 months. There were 2 cases of delayed healing in the internal fixation group and 1 case of delayed healing in the external fixation group, and all healed after symptomatic treatment. All patients in the two groups had no complication such as needle infection, nonunion at osteotomy, osteomyelitis, and so on. At last follow-up, MFTA standard was used to evaluate the recovery of force line. The results of external fixation group were all excellent, while the results of internal fixation group were excellent in 10 cases and good in 4 cases. The difference between the two groups was significant ( Z=-2.258, P=0.024). The HSS scores in the two groups were significantly improved at each time point after operation, and gradually improved with time after operation ( P<0.05). The HSS score of the external fixation group was significantly higher than that of the internal fixation group ( t=2.425, P=0.022) at 3 months after operation; and there was no significant difference between the two groups at other time points ( P>0.05). CONCLUSION: TSF has unique advantages in HTO treatment of MCOA patients and correction of lower extremity force line, such as shorter operation time, less bleeding, firm fixation, and less complications. It can accurately adjust the lower extremity force line after operation and has good effectiveness. It is an effective and safe fixation method.

[Introduction of EOS imaging system and its current research status in evaluating clinical value of lower limb force line].

The principle and technical background of EOS imaging system are introduced. Combining with the publicity of this technology and the existing literature reports, it is known that low dose EOS technology can reduce radiation dose by 5 to 10 times in the course of examination, and micro dose EOS can even reduce radiation dose by 45 times. The image quality is only high or low; the system has EOS 2D and 3D workstations, which can help clinicians to measure and evaluate coronal and sagittal force lines of lower limbs easily. The tilt and torsion of limbs can be measured three-dimensional after three-dimensional model reconstruction in the three-dimensional workstation. Using these results, preoperative evaluation can be carried out. It is helpful for clinicians to evaluate and improve preoperative planning and post-operative measurement and evaluation of surgical effect. In terms of measurement accuracy, a large number of literatures reported that the accuracy of EOS 2D measurement is comparable to that of general radiology measurement, while the accuracy of EOS 3D reconstruction measurement is comparable to that of CT and MRI. Based on the technical characteristics and advantages of EOS, this paper reviews the literature reports and research progress of EOS in evaluating the accuracy of lower limb alignment.

Application Effect of A New Modified 3D PSI in Total Knee Arthroplasty for Knee Osteoarthritis / 昆明医科大学学报

Objective To explore the application effect of new improved 3D printing individualized guidance(3D psi)in total knee arthroplasty(TKA)for knee osteoarthritis(KOA).Methods A total of 100 patients with KOA in 920th Hospital of Joint Logistics Support Force,PLA from January 2021 to January 2022 were selected,and were divided into 2 groups of 50 patients each using the randomized numerical table method.The control group was treated with conventional TKA,and the study group was treated with new improved 3D psi assisted TKA.The operation conditions,postoperative rehabilitation,complications,prosthesis component position deviation,knee range of motion(ROM),lower limb force line parameters[coronal distal femoral mechanical axis lateral angle(mldfa),lower limb mechanical axis angle(HKA)],gait parameters(percentage of support time,stride,pace),knee function(HSS score),quality of life(AIMS2 score)were observed.Results Com-pared with control group,the amount of intraoperative and postoperative blood loss and drainage volume 2 days after operation were less in the study group,and the operation time and hospital stay were shorter(P<0.05).The deviations of LTC Angle,FFC Angle,HKA Angle,LFC Angle and FTC Angle in the study group were smaller than those in the control group(P<0.05).At 3 months,6 months and 12 months after surgery,the percentage of knee ROM,supporting time,stride length and walking speed of the research group were higher than those of the control group,while the coronal-position mLDFA and HKA were lower than those of the control group(P<0.05).The proportion of WBC and PMN in joint fluid at 3 months,6 months and 12 months after surgery was lower than that in control group(P<0.05).The HSS score of the study group was higher than that of the control group at 3 months,6 months and 12 months after operation,and the AIMS2 score was lower than that of the control group(P<0.05).There was no statistically significant difference in the incidence of complications between the study group and the control group(P>0.05).Conclusion The new improved 3D PSI-assisted TKA treatment of KOA can optimize the surgical situation,improve operating accuracy,improve the patient's lower limb alignment,promote limb function recovery,help improve the quality of life,and has high safety.

[The assessment of the application of Taylor spatial frame in treatment of intermediate or distal tibiofibula fractures].

Objective: To determine the effectiveness and the safety of the Taylor spatial frame in treatment of intermediate or distal tibiofibula fractures. Methods: The clinical data of 74 patients with intermediate or distal tibiofibular fractures treated between January 2015 and January 2017 were retrospectively analyzed. According to fixation methods, they were divided into internal fixation group (26 cases) and external fixation group (48 cases). There was no significant difference in the age, gender, cause of injury, type of fracture, time from injury to operation between 2 groups ( P>0.05). The intraoperative blood loss, fracture healing time, fixator removal time, and complications were recorded and compared. The final function evaluation criteria of Johner-Wruhs humeral shaft fracture were used to evaluate the function of the affected limb. The lower limb force line recovery after operation was evaluated according to the standard evaluation of LUO Congfeng et al. Results: Both groups were followed up 6-22 months (median, 14 months). All patients obtained the fracture healing. The intraoperative blood loss, fracture healing time, and fixator removal time were significantly higher in the internal fixation group than those in the external fixation group ( P<0.05). There were 1 case of plate exposure, 1 case of delayed fracture healing, and 1 case of plate fracture in the internal fixation group; and there were 2 cases of delayed fracture healing and 4 cases of soft tissue defect in the external fixation group; no significant difference was found in the incidence of complications between 2 groups ( χ2=0.015, P=0.904). The function of the affected limb was evaluated by Johner-Wruhs standard at 10 months after operation, the results was excellent in 19 cases, good in 5 cases, and fair in 2 cases in the internal fixation group, with an excellent and good rate of 92.3%; the results was excellent in 42 cases, good in 3 cases, and fair in 2 cases in the external fixation group, with an excellent and good rate of 95.7%; showing no significant difference between 2 groups ( χ2=0.392, P=0.531). The lower limb force line recovery after operation was evaluated according to the standard evaluation of LUO Congfeng et al.at 4 months after operation, the results was excellent in 24 cases, fair in 1 case, poor in 1 case in the internal fixation group, with an excellent and good rate of 92.3%; the results was excellent in 46 cases, fair in 1 case, poor in 1 case in the external fixation group, with an excellent and good rate of 95.8%; showing no significant difference between 2 groups ( χ2=0.520, P=0.471). Conclusion: The use of Taylor spatial frame in the treatment of the intermediate or distal tibiofibular fractures can obviously reduce the healing time and complications than the internal fixation of the plate. It can reduce the fracture treatment cycle and is beneficial to the fracture healing and limb function recovery, which is relatively safe and reliable.

Clinical application of Taylor spatial frame in adjustment of lower extremity force line of knee medial compartmental osteoarthritis / 中国修复重建外科杂志

Objective: To explore the safety and effectiveness of Taylor spatial frame (TSF) in the treatment of medial compartmental osteoarthritis (MCOA) of the knee and the adjustment of the lower extremity force line at the same time. Methods: The clinical data of 30 patients with MCOA who underwent high tibial osteotomy (HTO) between October 2016 and April 2017 were retrospectively analyzed. According to the different fixation methods, they were divided into external fixation group (TSF external fixation, 16 cases) and internal fixation group (locking steel plate internal fixation, 14 cases). There was no significant difference between the two groups in gender, age, side, disease duration, mechanical femur tibia angle (MFTA), and other general data ( P>0.05). The operation time and intraoperative blood loss of the two groups were recorded and compared; MFTA was used to evaluate the recovery of the lower extremity force line at last follow-up; Hospital for Special Surgery (HSS) score was used to evaluate the clinical effecacy before operation and at 2 weeks, 1 month, and 3 months after operation. Results: The operation time and intraoperative blood loss of external fixation group were significantly less than those of internal fixation group ( P0.05). Conclusion: TSF has unique advantages in HTO treatment of MCOA patients and correction of lower extremity force line, such as shorter operation time, less bleeding, firm fixation, and less complications. It can accurately adjust the lower extremity force line after operation and has good effectiveness. It is an effective and safe fixation method.

A new minimally invasive spreader combined with less invasive stabilization system for proximal tibial fractures / 中国组织工程研究

BACKGROUND: The traditional surgical treatment of proximal tibial fractures has extensive dissection of the fracture site, and affects local blood circulation, increases the incidence of delayed union and nonunion. In recent years, the rising minimally invasive internal fixation system can protect the local soft tissue and blood circulation to the maximum extent, and provide better conditions for fracture healing. The application of new spreader also solves the problems of stability and durability of traditional manual traction reduction, and the combination of the two is gradually concerned. OBJECTIVE: To explore the effect of a new minimally invasive spreader assisted reduction and less invasive stabilization system for the treatment of proximal tibial fractures. METHODS: Twenty-two patients with proximal tibial fractures treated from May 2016 to October 2019 were studied and randomly assigned to control group and observation group (n=11 per group). Patients in the control group were treated with conventional manipulative reduction and conventional incision plate internal fixation. Patients in the observation group were treated with a new minimally invasive spreader assisted reduction and less invasive stabilization system. This study was approved by the Ethics Committee of Fifth Hospital, Guangzhou Medical University. RESULTS AND CONCLUSION: Compared with the control group, Rasmussen knee function score was better in the observation group at the last follow-up. Intraoperative blood loss, operation time, length of hospital stay, and weight-bearing time in the observation group were better than those in the control group. Postoperative complications such as joint limitation and delayed fracture healing were less in the observation group than in the control group. However, the healing time was not statistically significant between the two groups. Moreover, infection of the incision and loosening and fracture of the internal fixator were not statistically significant between the two groups. These indicated that the application of a new minimally invasive spreader combined with less invasive stabilization system for proximal tibial fractures can reduce surgical reduction time and local soft tissue damage, which is beneficial to early functional exercise and can reduce postoperative complications.

A mid-term clinical follow-up of unicompartmental knee arthroplasty with fixed bearing / 中国组织工程研究

BACKGROUND: Most of the domestic and foreign literatures reported the mid-term and long-term effects of the unicompartmental knee arthroplasty of the mobile bearing, but few reported the mid-term and long-term clinical effects of the unicompartmental knee arthroplasty of the fixed bearing. Simultaneously, most of the studies did not analyze the knee function recovery and the lower limb force line change at different time points after the fixed bearing unicompartmental knee arthroplasty, and also ignored the follow-up of the patients’ self-feeling after the unicompartmental knee arthroplasty. OBJECTIVE: To explore the mid-term clinical effect of fixed bearing unicompartmental knee arthroplasty in the treatment of medial compartment osteoarthritis of knee joint and to observe the change of force line of lower limbs. METHODS: From January 2014 to January 2015, a retrospective analysis was made of the data of 66 patients diagnosed as osteoarthritis of the medial compartment of the knee in the Department of Arthritis, Foshan Hospital of Traditional Chinese Medicine. According to the inclusion and exclusion criteria, 66 patients were included, including 18 males and 48 females, aged (62.36±16.33) years. The American Knee Society knee score and the hospital for special surgery knee score were used to assess the knee function before and 1, 3 and 5 years after the operation. Visual analogue scale score was utilized to evaluate the severity of knee. Forgotten joint score was used to assess the subjective feeling of prosthesis after unicompartmental knee arthroplasty. Hip-knee-ankle angle and tibiofemoral angle were measured using X-ray films before treatment and at follow-up to evaluate the force line of weight-bearing lower limbs. RESULTS AND CONCLUSION: (1) The postoperative follow-up time was 5-6 years, averagely 5.5 years. The incision healed in the first stage. There was no early complication such as joint infection or lower extremity deep vein thrombosis, and there was no prosthesis loosening, dislocation or other diseases of the contralateral compartment and patellofemoral joint. (2) The American Knee Society knee score clinical score, American Knee Society knee score function score, hospital for special surgery knee score, knee motion range and visual analogue scale score were lower at 1, 3 and 5 years after operation than those before treatment (P 0.05). (3) Forgotten joint score was higher at 3 and 5 years after treatment than that at 1 year after treatment (P 0.05). (4) Hip-knee-ankle angle and tibiofemoral angle were significantly improved after treatment in all patients compared with those before treatment (P 0.05). (5) The results show that the mid-term clinical effect of unicompartmental knee arthroplasty with fixed bearing is satisfactory, and the degree of self-prosthesis is high. After treatment, the force line of lower limbs was improved, and there was no significant change in the 5-year follow-up.

Introduction of EOS imaging system and its current research status in evaluating clinical value of lower limb force line / 中国骨伤

The principle and technical background of EOS imaging system are introduced. Combining with the publicity of this technology and the existing literature reports, it is known that low dose EOS technology can reduce radiation dose by 5 to 10 times in the course of examination, and micro dose EOS can even reduce radiation dose by 45 times. The image quality is only high or low; the system has EOS 2D and 3D workstations, which can help clinicians to measure and evaluate coronal and sagittal force lines of lower limbs easily. The tilt and torsion of limbs can be measured three-dimensional after three-dimensional model reconstruction in the three-dimensional workstation. Using these results, preoperative evaluation can be carried out. It is helpful for clinicians to evaluate and improve preoperative planning and post-operative measurement and evaluation of surgical effect. In terms of measurement accuracy, a large number of literatures reported that the accuracy of EOS 2D measurement is comparable to that of general radiology measurement, while the accuracy of EOS 3D reconstruction measurement is comparable to that of CT and MRI. Based on the technical characteristics and advantages of EOS, this paper reviews the literature reports and research progress of EOS in evaluating the accuracy of lower limb alignment.

Study on the characteristics of biology force line of proximal femur based on structural topology optimization / 生物医学工程学杂志

Internal fixator is usually adopted in the treatment of bone fractures. In order to achieve anatomical reduction and effective fixation of fractures, the placement of internal fixators should comply with the biology force line of the bone and adapt to the specific anatomical morphological characteristics of the cortical bone. In order to investigate the distribution characteristics and formation regularity of biology force line and cortical thickness of human bone, three-dimensional model of proximal femur is established by using three-dimensional reconstruction technique in this paper. The normal physiological stress distribution of proximal femur is obtained by finite element analysis under three kinds of behavior conditions: one-legged stance, abduction and adduction. The structural topology optimization method is applied to simulate the cortex of the proximal femur under the combined action of three kinds of behavior conditions, and the anatomic morphological characteristics of the proximal femur are compared. The distribution trend of biology force line of proximal femur and the characteristics of cortex are analyzed. The results show that the biology force lines of bone structure and the morphological characteristics of cortex depend on the load of human activities. The distribution trend of biology force line is related to the direction of trabecular bone and the ridge trend and firmness of cortex when bone is loaded physiologically. The proposed analytical method provides a solution to determine the biology force line of bone and the distribution characteristics of cortex. The conclusions obtained may guide the reasonable placement of internal fixator components of fracture.

The assessment of the application of Taylor spatial frame in treatment of intermediate or distal tibiofibula fractures / 中国修复重建外科杂志

Objective: To determine the effectiveness and the safety of the Taylor spatial frame in treatment of intermediate or distal tibiofibula fractures. Methods: The clinical data of 74 patients with intermediate or distal tibiofibular fractures treated between January 2015 and January 2017 were retrospectively analyzed. According to fixation methods, they were divided into internal fixation group (26 cases) and external fixation group (48 cases). There was no significant difference in the age, gender, cause of injury, type of fracture, time from injury to operation between 2 groups ( P>0.05). The intraoperative blood loss, fracture healing time, fixator removal time, and complications were recorded and compared. The final function evaluation criteria of Johner-Wruhs humeral shaft fracture were used to evaluate the function of the affected limb. The lower limb force line recovery after operation was evaluated according to the standard evaluation of LUO Congfeng et al. Results: Both groups were followed up 6-22 months (median, 14 months). All patients obtained the fracture healing. The intraoperative blood loss, fracture healing time, and fixator removal time were significantly higher in the internal fixation group than those in the external fixation group ( P<0.05). There were 1 case of plate exposure, 1 case of delayed fracture healing, and 1 case of plate fracture in the internal fixation group; and there were 2 cases of delayed fracture healing and 4 cases of soft tissue defect in the external fixation group; no significant difference was found in the incidence of complications between 2 groups ( χ2=0.015, P=0.904). The function of the affected limb was evaluated by Johner-Wruhs standard at 10 months after operation, the results was excellent in 19 cases, good in 5 cases, and fair in 2 cases in the internal fixation group, with an excellent and good rate of 92.3%; the results was excellent in 42 cases, good in 3 cases, and fair in 2 cases in the external fixation group, with an excellent and good rate of 95.7%; showing no significant difference between 2 groups ( χ2=0.392, P=0.531). The lower limb force line recovery after operation was evaluated according to the standard evaluation of LUO Congfeng et al.at 4 months after operation, the results was excellent in 24 cases, fair in 1 case, poor in 1 case in the internal fixation group, with an excellent and good rate of 92.3%; the results was excellent in 46 cases, fair in 1 case, poor in 1 case in the external fixation group, with an excellent and good rate of 95.8%; showing no significant difference between 2 groups ( χ2=0.520, P=0.471). Conclusion: The use of Taylor spatial frame in the treatment of the intermediate or distal tibiofibular fractures can obviously reduce the healing time and complications than the internal fixation of the plate. It can reduce the fracture treatment cycle and is beneficial to the fracture healing and limb function recovery, which is relatively safe and reliable.

La configuración del campo de la rectoría escolar oficial en Colombia / A Configuraçao do campo da reitoria escolar oficial na Colômbia / The configuration of the official school principalship in Colombia

Este artículo se inscribe en el contexto de las reformas educativas contemporáneas y caracteriza cómo se está configurando el campo de la rectoría oficial escolar en Colombia a partir de las relaciones de poder que se generan entre el rector o rectora y las dimensiones macropolítica y micropolítica de las instituciones educativas. Los resultados muestran cómo el campo de la rectoría está fuertemente regulado por las normas y políticas educativas nacionales y la recontextualización que se hace de éstas en los escenarios macropolíticos locales. El campo del rector o rectora se configura a través de tres líneas de fuerza de dominio que cambian la orientación de la rectoría, afectan su función y generan cambios en sus relaciones: la primera hala al rector o rectora hacia el entorno en búsqueda de recursos, proyectos y relaciones con el gobierno local; la segunda hala al rector o rectora hacia la promoción de la democratización de la institución educativa y el disciplinamiento de los maestros y maestras; la tercera se orienta hacia la rendición de cuentas. Concluimos que la reconfiguración del campo del rector o rectora se da en un contexto socialmente problematizado y signado por amplias expectativas sobre el papel de la escuela y los rectores y rectoras. La labor directiva está marcada por un sesgo altamente administrativo, una orientación hacia el disciplinamiento de los maestros y maestras, y la rendición de cuentas. En medio de restricciones, los rectores y rectoras ensayan estrategias de negociación, y promueven acciones para lograr cumplir con los objetivos institucionales, con las demandas de la comunidad escolar y con las expectativas de su rol.

Este artigo fica no contexto das reformas educativas contemporâneas e caracteriza como se configura o campo da reitoria oficial escolar na Colômbia a partir das relações de poder que se geram entre o reitor e as dimensões macropolítica e micropolítica das instituições educativas. Os resultados indicam como o campo da reitoria está regulado fortemente pelas normas, políticas educativas nacionais e pela sua re-contextualização nos cenários macropoliticos locais. O campo do reitor configura-se através de três linhas de força de domínio que alteram a orientação da reitoria, afetam sua função e geram mudanças nas suas relações. A primeira impulsiona o reitor para o meio na busca de recursos, projetos e relações como o governo local; a segunda impulsiona o reitor para a promoção da democratização da instituição educativa e para o disciplinamento dos professores e das professoras; a terceira orienta-se para a apresentação de relatórios. O artigo conclui que a reconfiguração do campo do reitor se apresenta num contexto socialmente problematizado e caracterizado por expectativas amplas sobre o papel da escola e dos reitores e reitoras. A função diretiva está marcada por um preconceito altamente administrativo, uma orientação para o disciplinamento dos professores e das professoras, como também para a apresentação de relatórios. No meio de restrições, os reitores e as reitoras ensaiam estratégias de negociação e promovem ações para satisfazer os objetivos institucionais, as demandas da comunidade escolar e as expectativas do seu papel.

This article belongs in the context of contemporary school reforms and characterizes how the Colombian school principalship is being configured from the power relations generated between the principal and the macropolitical and micropolitical dimensions in educational institutions. The results show how the field of principalship is heavily regulated by national educational norms and policies and by their corresponding recontextualization in the local macropolitical scenarios. The principalship field is configured through three domain force lines that change the principalship orientation, affect its function and generate changes in their relations. The first force induces the principal towards the search for resources, projects and their relations; the second induces the principal towards the promotion of the democratization of the educational institution and to disciplining both male and females teachers; and the third refers to reporting management activities. The conclusion states that the reconfiguration of the principal's field takes place in context that is socially problematized and marked by wide expectations about the role of schools and by both male and female principals. The directive function is widely marked by a highly administrative bias, an orientation towards the disciplining of teachers and towards the reporting of management activities. In a world of restrictions, the principals try new negotiation strategies and promote actions aiming at meeting institutional objectives, along with the demands from the school and the expectations resulting from their roles.