Since the assumption of plane sections cannot be applied to the strain of unbonded tendons in prestressed concrete beams subjected to loadings,a moment-curvature nonlinear analysis method is used to develop analytical...Since the assumption of plane sections cannot be applied to the strain of unbonded tendons in prestressed concrete beams subjected to loadings,a moment-curvature nonlinear analysis method is used to develop analytical programs from stress increases in unbonded tendons at the ultimate limit state.Based on the results of model testing and simulation analysis,equations are proposed to predict the stress increase in tendons at the ultimate state in simple or continuous beams of partially prestressed concrete,considering the loading type,non-prestressed reinforcement index βp,prestressing reinforcement index βs,and span-depth ratio L/h as the basic parameters.Results of 380 beams studied here and test results for 35 simple beams obtained by the China Academy of Building Research were compared with those from prediction equations given in codes and other previous studies.The comparison reveals that the values predicted by the proposed equations agree well with experimental results.展开更多
Epaxial tendons play an important role in the study of the musculoskeletal system and locomotory style of dinosaurs. Although the ossified epaxial tendon lattice is fairly well known in Iguanodontoidea, only recently ...Epaxial tendons play an important role in the study of the musculoskeletal system and locomotory style of dinosaurs. Although the ossified epaxial tendon lattice is fairly well known in Iguanodontoidea, only recently has knowledge of this complex been extended to ceratopsians. This study concerns the gross morphology and microstructure of the tendon lattice in Psittacosaurus, a basal ceratopsian. As in the neoceratopsian Chasmosaurus, the ossified tendons of Psittacosaurus form a three -layered, lattice-like structure. The microstructure of the tendons in large psittacosaur individuals retains an early stage of ossification, as in juvenile birds and nestling hadrosaurs, suggesting a slow developmental rate of ossification of the tendons in psittacosaur ontogeny. Comparative study indicates that a lattice-like arrangement of three-layered epaxial tendons is widely distributed in Cerapoda. This pattern also extends to Ankylosauria, implying a similar pattern of the epaxial muscles through the ornithischian clade. In addition, comparison with crocodiles implies that the different morphology of ossified tendons in dinosaurs may be associated with adaptive aspects of their paleobiology, not simply a side effect of skeletal ossification. In contrast to the short tendons in quadrupedal Chasmosaurus and Protoceratops, the elongated tendons in Psittacosaurus may be related to the bipedal locomotion characteristic of this taxon.展开更多
BACKGROUND False tendon is a common intraventricular anatomical variation. It refers to a fibroid or fibromuscular structure that exists in the ventricle besides the normal connection of papillary muscle and mitral or...BACKGROUND False tendon is a common intraventricular anatomical variation. It refers to a fibroid or fibromuscular structure that exists in the ventricle besides the normal connection of papillary muscle and mitral or tricuspid valve. A large number of clinical studies have suggested that there is a significant correlation between false tendons and premature ventricular complexes. However, few studies have verified this correlation during radiofrequency catheter ablation of premature ventricular complexes.CASE SUMMARY A 45-year-old male was admitted to receive radiofrequency ablation for symptomatic premature ventricular complexes. A three-dimensional model of the left ventricle was established by intracardiac echocardiography using the CartoSound^TM mapping system. In addition to the left anterior papillary muscle,the posterior papillary muscle was mapped. False tendons were found at the base of the interventricular septum, and the other end was connected to the left ventricular free wall near the apex. An irrigated touch force catheter was advanced into the left ventricle via the retrograde approach. The earliest activation site was marked at the interventricular septum attachment of the false tendons and was successfully ablated.CONCLUSION This case verified that false tendons can cause premature ventricular complexes and may be cured by radiofrequency ablation guided by intracardiac echocardiography with the Carto Sound TM system.展开更多
Based on full-scale segment model tests of the abnormally shaped anchorage zone of the Maling River cable-stayed bridge pylon and FEM analysis, its mechanical and deformation properties were obtained, and the validity...Based on full-scale segment model tests of the abnormally shaped anchorage zone of the Maling River cable-stayed bridge pylon and FEM analysis, its mechanical and deformation properties were obtained, and the validity of FEM analysis was verified. An optimal layout of prestressed tendons in the anchorage zone was obtained by using the strut-and-tie method （STM）. The comparison FEM analysis between the full-scale segment model and the optimal prestressed tendons model show that： the optimal model not only saves prestressed tendons, but also achieves the same cracking resistance; STM method is reliable and accurate in the analysis of the abnormally shaped anchorage zone of cable-stayed bridge pylon.展开更多
After grouting the ducts in a large band beam and one-way slab post-tensioned floor system in a large shopping mall （in excess of 1.5 km2 in plan）, doubts arose concerning the level of initial prestress and the stre...After grouting the ducts in a large band beam and one-way slab post-tensioned floor system in a large shopping mall （in excess of 1.5 km2 in plan）, doubts arose concerning the level of initial prestress and the strength and serviceability of the slabs was questioned. To assess the strength of the slabs, it was assumed, as a worst case scenario, that some spans may have been constructed with zero initial prestress. Load tests on prototype specimens, with similar dimensions and reinforcement quantities as the floor slabs, were performed to assess the stress development in initially unstressed, but fully grouted, tendons. Unexpected bond failures occurred at the junctions of slab and band beam where the abrupt change in section depth caused a sudden change in tendon stress. The maximum stress that was developed in the initially unstressed tendons at these locations was about 60% of the strength of the tendons.展开更多
Introduction: There has been a surge in the use of tendoscopic surgery for treating peroneal tendons instability. The novelty of this approach demanded a literature review of its indications, limitations, and clinical...Introduction: There has been a surge in the use of tendoscopic surgery for treating peroneal tendons instability. The novelty of this approach demanded a literature review of its indications, limitations, and clinical outcomes. Aim: a literature review of the clinical studies reporting on tendoscopic peroneal tendon stabilisation surgery along with its outcomes and complications. Methods: We carried out a comprehensive review of the literature up until September 2022 with an extensive search of the MEDLINE, Embase and Cochrane library databases. Results: Initial search resulted in 66 articles. Four duplicate articles were removed. Further 30 articles were excluded after title and abstract screening. Eight studies satisfied the inclusion criteria and were included in this review. Articles were analysed for outcomes and complications. Conclusion: The tendoscopic technique for peroneal tendon instability is an effective and safe surgical technique with very low failure rate. Levels of Evidence: Level IV.展开更多
Summary： To identify the best suture techniques for the tendon repair, the biomechanical properties of tendons sutured by different methods were dynamically examined. 140 chickens were divided into 2 groups equally：...Summary： To identify the best suture techniques for the tendon repair, the biomechanical properties of tendons sutured by different methods were dynamically examined. 140 chickens were divided into 2 groups equally： group A and group B. The tendon of the right side was subjected to injury-repair process, and the tendons of the left sides served as controls in both groups. In group A, ＂figure-of- 8＂ suture, modified Kessler suture and Bunnell suture were used for the 2nd to 4th paws respectively, while in group B, Kleinert suture, Tsuge suture and Ikuta suture were used. On the day 0, 3, 7, 14, 21, 28, 42 after operation, 10 animals were sacrificed and the flexor tendons of both sides were harvested for strength test. The results showed that the initial strength of the repaired tendons and the strength after 6 weeks following tendon cut were far below those of intact tendons, irrespective of suture techniques used. With the 6 techniques, the P of tendons repaired by Tsuge suture was increased continually, reaching the highest value on the 42nd day. The P of tendons sutured by the modified Kessler suture was slightly lower than that by Tsuge suture, but it was increased steadily in healing. The tendons repaired by figure-of-8 suture yielded the lowest P It was concluded that Tsuge suture and modified Kessler suture were the best techniques for tendon repair.展开更多
This study investigates the viscoelastic behavior of soft bio-fibres in association with their fractal structures. A spring-dashpot fractal network with the self-similar topology, named the -type fractal ladder hyper-...This study investigates the viscoelastic behavior of soft bio-fibres in association with their fractal structures. A spring-dashpot fractal network with the self-similar topology, named the -type fractal ladder hyper-cell (FLHC), is abstracted from the micro/nano-structure of ligaments and tendons (LTs). Its constitutive operator is derived by the Heaviside operational calculus, which is of intrinsic fractional order. In terms of this operator, the long-term viscoelastic relaxation of bio-fibres arising from the fractal ladder topology is expounded. In addition, the fractional-order viscoelastic constitutive equation is obtained based on the FLHC of LTs, and its results are consistent with those of available human knee and spinal LT relaxation experiments. Results on the constitutive equation of FLHCs are formulated into two propositions. The multidisciplinary invariance and implications from the fractal ladder pattern of bio-fibres are also discussed.展开更多
Active tendon, consisting of a displacement actuator and a collocated force sensor, was first presented by Preumont and his co-workers to attenuate the vibration of large flexible space structures, and the control alg...Active tendon, consisting of a displacement actuator and a collocated force sensor, was first presented by Preumont and his co-workers to attenuate the vibration of large flexible space structures, and the control algorithm adopted by them was integral force feedback. This paper presents a new proportional-integral （PI） force feedback algorithm to achieve larger damping ratios for the structure without the requirement of structure model. Stability of the control system is shown, and simulations of a structure similar to JPL-MPI demonstrate the effectiveness of the proposed algorithm for vibration control of space structures.展开更多
Fracture of an ossification of the Achilles tendon(OAT)is a rare entity,and its etiology,pathology,and treatment remain unclear.We reviewed and scrutinized 18 cases(16 articles)of the fracture of an OAT.The most commo...Fracture of an ossification of the Achilles tendon(OAT)is a rare entity,and its etiology,pathology,and treatment remain unclear.We reviewed and scrutinized 18 cases(16 articles)of the fracture of an OAT.The most common etiologies of the ossifications include previous surgery and trauma.The fractures often occur without any trigger or with minimal trigger.The long,>5 cm,ossification in the body of the Achilles tendon may have a higher risk of fracture.The OAT itself is often asymptomatic;however,its fracture causes severe local pain,swelling,and weakness of plantar flexion,which forces patients to undergo aggressive treatments.Regarding the treatments of the fractures,nonoperative treatment by immobilizing ankle joint could be an option for elderly patients.However,because it often cannot produce satisfactory results in younger patients,surgical treatment is typically recommended.Excision of the fractured mass and repairing the tendon is applicable if the remnant is enough.If there is a defect after the excision,reconstruction with autologous grafts or adjacent tendon transfer is performed.Gastrocnemius fascia turndown flap,hamstring tendon and tensor fascia lata are used as autologous grafts,whereas peroneus brevis and flexor hallucis longus tendons are used for the tendon transfer.If the fracture of an OAT is treated properly,the functional result will be satisfactory.展开更多
Tendon ruptures remain a significant musculoskeletal injury. Despite advances in surgical techniques and procedures, traditional repair techniques maintain a high incidence of rerupture or tendon elongation. Mechanica...Tendon ruptures remain a significant musculoskeletal injury. Despite advances in surgical techniques and procedures, traditional repair techniques maintain a high incidence of rerupture or tendon elongation. Mechanical loading and biochemical signaling both control tissue healing. This has led some researchers to consider using a technique based on tension regulation at the suture line for obtaining good healing. However, it is unknown how they interact and to what extent mechanics control biochemistry. This review will open the way for understanding the interplay between mechanical loading and the process of tendon healing.展开更多
BACKGROUND Injuries to the pectoralis major are infrequent,with only a few hundred cases currently recorded in the literature.CASE SUMMARY We report a case of a patient who sustained bilateral pectoralis major tendon ...BACKGROUND Injuries to the pectoralis major are infrequent,with only a few hundred cases currently recorded in the literature.CASE SUMMARY We report a case of a patient who sustained bilateral pectoralis major tendon ruptures.While other cases of bilateral pectoralis major tears have been reported in the literature,the operative management in this report differs.Due to delayed presentation of the patient right and left pectoralis major repairs were performed simultaneously.CONCLUSION Patients with delayed presentation of bilateral pectoralis major tendon ruptures can undergo simultaneous repair of both tendon with a good postoperative outcome and high patient satisfaction.展开更多
Normal tendon substance is strong and is unlikely to break before the muscle origin, muscle, musculotendinous junction or the insertion yield. In almost all the cases, closed ruptures of the flexor tendon within the t...Normal tendon substance is strong and is unlikely to break before the muscle origin, muscle, musculotendinous junction or the insertion yield. In almost all the cases, closed ruptures of the flexor tendon within the tendinous portion have been described in association with distinct underlying pathologies. We report a case of flexor tendon rupture of the index finger which seems to be associated with previous trauma occurred more than 40 years ago and abnormal healing.展开更多
Based on the understanding of lower limb numbness after stroke in Zhuang medicine, this study makes diagnosis and treatment of lower limb numbness after stroke from the clinical differentiation and treatment ideas of ...Based on the understanding of lower limb numbness after stroke in Zhuang medicine, this study makes diagnosis and treatment of lower limb numbness after stroke from the clinical differentiation and treatment ideas of "numbness due to Shaoyang (lesser Yang)" through Zhuang Medicine Meridian Tendon Therapy. The triple therapy of meridian tendon Tuina+acupuncture+cupping originally created by Zhuang medicine and head bloodletting by Zhuang medicine were used to improve the numbness symptoms of patients. This provides a new thinking mode for acupuncture and moxibustion treatment of lower limb numbness after stroke.展开更多
After corrosion failure of post-tensioned tendons was identified in a Florida bridge in early 2011, laboratory tests were conducted in this study on extracted sections from the failed tendons to identify the grout pro...After corrosion failure of post-tensioned tendons was identified in a Florida bridge in early 2011, laboratory tests were conducted in this study on extracted sections from the failed tendons to identify the grout properties and makeup leading to the failure and also to elucidate the mechanism of corrosion. The initial steps in identification of PT tendons with a high propensity for corrosion initiation or damaged included a detailed visual inspection and identification of voids in the grout. Voids in tendon can be a result of bleed water formation or construction problems. General characteristics of the deficient grout and corrosion behavior of steel in the affected bridge gave a first approach to assessing grout deficiency and corrosion susceptibility. However, refinements in the understanding of the mechanisms causing grout segregation and the elucidation of the role of sulfates, oxygen content, and pore water pH in corrosion development are required.展开更多
Prestressed concrete segmental box girder bridges are composed of short concrete segments that are either precast or cast in situ and then joined together by longitudinally post-tensioning internal,external,or mixed t...Prestressed concrete segmental box girder bridges are composed of short concrete segments that are either precast or cast in situ and then joined together by longitudinally post-tensioning internal,external,or mixed tendons.The objectives of this study are to monitor the construction process of the external prestressing tendons to strengthen the bridge structure and perform a field load test to measure the strain and the deflection of the anchorage devices of the external prestressing tendons to determine the state of these devices after tension forces are applied.The monitoring process of the external prestressing tendons construction includes inspecting the cracks in the diaphragm anchorage and the deviation block devices before the tension forces are applied to the external tendons;measuring the deformation of the steel deviation cross beam during the tension process;measuring the deformation of the box girder after different levels of tension forces are applied;measuring the elongation of the external tendons in each level of the tension;and measuring the natural frequency of the external tendons after the tension process is complete.The results of the monitoring process show that the measured values of the deformation,the elongation,and the natural frequency meet the requirements.Therefore,there is no damage during the construction and the tensioning of the external prestressing tendons.A field load test is performed to the anchorage beam,the steel deviation block devices,and the steel deviation cross beam.The field load test results of the anchorage devices show that the values of the strains,the stresses,and the deflection are less than the respective allowable limit values in the requirements.Therefore,the anchorage devices have sufficient strength,and the working state is good after the tension forces are applied to the external prestressing tendons.展开更多
BACKGROUND Anterior cruciate ligament(ACL)reconstruction using bone-patellar tendon-bone(BPTB)autografts remains the gold standard for young,active individuals due to its superior biomechanical strength and bone-to-bo...BACKGROUND Anterior cruciate ligament(ACL)reconstruction using bone-patellar tendon-bone(BPTB)autografts remains the gold standard for young,active individuals due to its superior biomechanical strength and bone-to-bone healing.However,donor site morbidity,particularly anterior knee pain(AKP),limits its utilization despite its advantages.Various techniques have been proposed to reduce AKP,but they show variable outcomes and several limitations.AIM To assess the incidence and severity of AKP following BPTB ACL reconstruction using an autologous bone grafting technique.METHODS We conducted a retrospective observational study of 24 patients aged 20-45 years,who had primary ACL reconstruction with BPTB grafts.During surgery,autologous cancellous bone generated from tunnel drilling was used to fill the patellar and tibial donor site voids after graft fixation.All patients were followed up for at least twelve months.Using the Kujala Anterior Knee Pain Score,clinical outcomes were evaluated,including the pain-specific subcomponent.RESULTS With scores ranging from 86 to 100,the average overall Kujala score was 95.67±4.01.No patient scored below 85.There was no complication such as patellar fracture,tibial tuberosity fracture,or infection.Grouped data showed 20.8%of patients scored 100,whereas 54.2%scored between 95 and 99,and 25%scored between 86 and 94.One patient(4.2%)had an 8/10 pain subcomponent,whereas 23 patients(95.8%)had a 10/10.CONCLUSION This procedure is easy to incorporate into routine surgical practice,cost-effective and reproducible without requiring extra incisions or raising the patient’s surgical expenses.Excellent short-term results back up this technique.展开更多
Background It has been demonstrated that bone tunnel widening could appear after knee anterior cruciate ligament (ACL) reconstruction, especially for those patients whose ruptured ACL were reconstructed with semitendi...Background It has been demonstrated that bone tunnel widening could appear after knee anterior cruciate ligament (ACL) reconstruction, especially for those patients whose ruptured ACL were reconstructed with semitendinosus and gracilis tendons. Many factors can influence the extent of tunnel widening. Few studies have investigated the relationship between bone tunnel widening and rehabilitation procedures. This research was carried out to find the rehabilitation procedures' influence on the tibial bone tunnel widening after ACL reconstruction. Methods Sixty-five cases, whose ACL reconstructions were done using quadrupled semitendinosus and gracilis tendons, were divided into two groups. Group A had 33 cases, 19 men, 14 women, averaged (31.2±12.4) years old, only ACL reconstruction was done using Paessler's technique, and aggressive rehabilitation procedure was used for function recovery post operation. Group B had 32 cases, 20 men, 12 women, averaged (30.3±10.3) years old. Except for ACL reconstruction, every patient in group B accepted meniscus repair using re-fixation methods or cartilage repair using microfracture technique, conservative rehabilitation procedure was used post operation. Six months post operation, standard posterior-anterior radiographic plates were taken for each case, CorelDRAW 8.0 software was used to digitize all X-ray plates and measure the upper, middle and lower parts of the tibial tunnel. Magnification effect of X-ray plates was taken out after measurement. Results Six months after ACL reconstruction the tibial tunnel widening of the upper, middle and lower parts on both the posterior-anterior and lateral X-ray plates in Group A with aggressive rehabilitation procedure was much more serious than in Group B with conservative rehabilitation. KT-1000 knee stability measurement and clinical manifestation showed no difference between the two groups. Conclusions Rehabilitation procedure after ACL reconstruction is one of the reasons for tunnel widening. It not only can directly influence the function recovery of ACL reconstructed knee, but also perhaps indirectly influence the function recovery and long-term clinical result of the operated knee by influencing the tunnel widening.展开更多
Tendon and ligament(TL)injuries affect millions of people annually.Biopolymers play a significant role in TL tissue repair,whether the treatment relies on tissue engineering strategies or using artificial tendon graft...Tendon and ligament(TL)injuries affect millions of people annually.Biopolymers play a significant role in TL tissue repair,whether the treatment relies on tissue engineering strategies or using artificial tendon grafts.The biopolymer governs the mechanical properties,biocompatibility,degradation,and fabrication method of the TL scaffold.Many natural,synthetic and hybrid biopolymers have been studied in TL regeneration,often combined with therapeutic agents and minerals to engineer novel scaffold systems.However,most of the advanced biopolymers have not advanced to clinical use yet.Here,we aim to review recent biopolymers and discuss their features for TL tissue engineering.After introducing the properties of the native tissue,we discuss different types of natural,synthetic and hybrid biopolymers used in TL tissue engineering.Then,we review biopolymers used in commercial absorbable and non-absorbable TL grafts.Finally,we explain the challenges and future directions for the development of novel biopolymers in TL regenerative treatment.展开更多
基金Project supported by the National Natural Science Foundation of China (No.50178026)the New Century Excellent Talents in UniversityChangjiang Scholars Program of China (No.2009-37)
文摘Since the assumption of plane sections cannot be applied to the strain of unbonded tendons in prestressed concrete beams subjected to loadings,a moment-curvature nonlinear analysis method is used to develop analytical programs from stress increases in unbonded tendons at the ultimate limit state.Based on the results of model testing and simulation analysis,equations are proposed to predict the stress increase in tendons at the ultimate state in simple or continuous beams of partially prestressed concrete,considering the loading type,non-prestressed reinforcement index βp,prestressing reinforcement index βs,and span-depth ratio L/h as the basic parameters.Results of 380 beams studied here and test results for 35 simple beams obtained by the China Academy of Building Research were compared with those from prediction equations given in codes and other previous studies.The comparison reveals that the values predicted by the proposed equations agree well with experimental results.
基金provided by the National Natural Science Foundation of China(NSFC Grant No.40532008)supported by NSFC(Grant No.40802007)Travel support for RCF was by a grant from the Chinese Ministry of Education(No.2006-233).
文摘Epaxial tendons play an important role in the study of the musculoskeletal system and locomotory style of dinosaurs. Although the ossified epaxial tendon lattice is fairly well known in Iguanodontoidea, only recently has knowledge of this complex been extended to ceratopsians. This study concerns the gross morphology and microstructure of the tendon lattice in Psittacosaurus, a basal ceratopsian. As in the neoceratopsian Chasmosaurus, the ossified tendons of Psittacosaurus form a three -layered, lattice-like structure. The microstructure of the tendons in large psittacosaur individuals retains an early stage of ossification, as in juvenile birds and nestling hadrosaurs, suggesting a slow developmental rate of ossification of the tendons in psittacosaur ontogeny. Comparative study indicates that a lattice-like arrangement of three-layered epaxial tendons is widely distributed in Cerapoda. This pattern also extends to Ankylosauria, implying a similar pattern of the epaxial muscles through the ornithischian clade. In addition, comparison with crocodiles implies that the different morphology of ossified tendons in dinosaurs may be associated with adaptive aspects of their paleobiology, not simply a side effect of skeletal ossification. In contrast to the short tendons in quadrupedal Chasmosaurus and Protoceratops, the elongated tendons in Psittacosaurus may be related to the bipedal locomotion characteristic of this taxon.
文摘BACKGROUND False tendon is a common intraventricular anatomical variation. It refers to a fibroid or fibromuscular structure that exists in the ventricle besides the normal connection of papillary muscle and mitral or tricuspid valve. A large number of clinical studies have suggested that there is a significant correlation between false tendons and premature ventricular complexes. However, few studies have verified this correlation during radiofrequency catheter ablation of premature ventricular complexes.CASE SUMMARY A 45-year-old male was admitted to receive radiofrequency ablation for symptomatic premature ventricular complexes. A three-dimensional model of the left ventricle was established by intracardiac echocardiography using the CartoSound^TM mapping system. In addition to the left anterior papillary muscle,the posterior papillary muscle was mapped. False tendons were found at the base of the interventricular septum, and the other end was connected to the left ventricular free wall near the apex. An irrigated touch force catheter was advanced into the left ventricle via the retrograde approach. The earliest activation site was marked at the interventricular septum attachment of the false tendons and was successfully ablated.CONCLUSION This case verified that false tendons can cause premature ventricular complexes and may be cured by radiofrequency ablation guided by intracardiac echocardiography with the Carto Sound TM system.
基金The National Natural Science Foundation of China (No.50925828)
文摘Based on full-scale segment model tests of the abnormally shaped anchorage zone of the Maling River cable-stayed bridge pylon and FEM analysis, its mechanical and deformation properties were obtained, and the validity of FEM analysis was verified. An optimal layout of prestressed tendons in the anchorage zone was obtained by using the strut-and-tie method （STM）. The comparison FEM analysis between the full-scale segment model and the optimal prestressed tendons model show that： the optimal model not only saves prestressed tendons, but also achieves the same cracking resistance; STM method is reliable and accurate in the analysis of the abnormally shaped anchorage zone of cable-stayed bridge pylon.
文摘After grouting the ducts in a large band beam and one-way slab post-tensioned floor system in a large shopping mall （in excess of 1.5 km2 in plan）, doubts arose concerning the level of initial prestress and the strength and serviceability of the slabs was questioned. To assess the strength of the slabs, it was assumed, as a worst case scenario, that some spans may have been constructed with zero initial prestress. Load tests on prototype specimens, with similar dimensions and reinforcement quantities as the floor slabs, were performed to assess the stress development in initially unstressed, but fully grouted, tendons. Unexpected bond failures occurred at the junctions of slab and band beam where the abrupt change in section depth caused a sudden change in tendon stress. The maximum stress that was developed in the initially unstressed tendons at these locations was about 60% of the strength of the tendons.
文摘Introduction: There has been a surge in the use of tendoscopic surgery for treating peroneal tendons instability. The novelty of this approach demanded a literature review of its indications, limitations, and clinical outcomes. Aim: a literature review of the clinical studies reporting on tendoscopic peroneal tendon stabilisation surgery along with its outcomes and complications. Methods: We carried out a comprehensive review of the literature up until September 2022 with an extensive search of the MEDLINE, Embase and Cochrane library databases. Results: Initial search resulted in 66 articles. Four duplicate articles were removed. Further 30 articles were excluded after title and abstract screening. Eight studies satisfied the inclusion criteria and were included in this review. Articles were analysed for outcomes and complications. Conclusion: The tendoscopic technique for peroneal tendon instability is an effective and safe surgical technique with very low failure rate. Levels of Evidence: Level IV.
文摘Summary： To identify the best suture techniques for the tendon repair, the biomechanical properties of tendons sutured by different methods were dynamically examined. 140 chickens were divided into 2 groups equally： group A and group B. The tendon of the right side was subjected to injury-repair process, and the tendons of the left sides served as controls in both groups. In group A, ＂figure-of- 8＂ suture, modified Kessler suture and Bunnell suture were used for the 2nd to 4th paws respectively, while in group B, Kleinert suture, Tsuge suture and Ikuta suture were used. On the day 0, 3, 7, 14, 21, 28, 42 after operation, 10 animals were sacrificed and the flexor tendons of both sides were harvested for strength test. The results showed that the initial strength of the repaired tendons and the strength after 6 weeks following tendon cut were far below those of intact tendons, irrespective of suture techniques used. With the 6 techniques, the P of tendons repaired by Tsuge suture was increased continually, reaching the highest value on the 42nd day. The P of tendons sutured by the modified Kessler suture was slightly lower than that by Tsuge suture, but it was increased steadily in healing. The tendons repaired by figure-of-8 suture yielded the lowest P It was concluded that Tsuge suture and modified Kessler suture were the best techniques for tendon repair.
基金Project supported by the National Natural Science Foundation of China(No.11672150)the Beijing Nova Program Interdisciplinary Cooperation Project(No.xxjc201705)+1 种基金the Capital Clinical Special Promotion Project(No.Z161100000516233)the Key Issue of the 12th Five-Year Plan of People’s Liberation Army of China(No.BKJ13J004)
文摘This study investigates the viscoelastic behavior of soft bio-fibres in association with their fractal structures. A spring-dashpot fractal network with the self-similar topology, named the -type fractal ladder hyper-cell (FLHC), is abstracted from the micro/nano-structure of ligaments and tendons (LTs). Its constitutive operator is derived by the Heaviside operational calculus, which is of intrinsic fractional order. In terms of this operator, the long-term viscoelastic relaxation of bio-fibres arising from the fractal ladder topology is expounded. In addition, the fractional-order viscoelastic constitutive equation is obtained based on the FLHC of LTs, and its results are consistent with those of available human knee and spinal LT relaxation experiments. Results on the constitutive equation of FLHCs are formulated into two propositions. The multidisciplinary invariance and implications from the fractal ladder pattern of bio-fibres are also discussed.
基金the National Natural Science Foundation of China (10572070)Tsinghua Basic Research Foundation (JCqn2005029)
文摘Active tendon, consisting of a displacement actuator and a collocated force sensor, was first presented by Preumont and his co-workers to attenuate the vibration of large flexible space structures, and the control algorithm adopted by them was integral force feedback. This paper presents a new proportional-integral （PI） force feedback algorithm to achieve larger damping ratios for the structure without the requirement of structure model. Stability of the control system is shown, and simulations of a structure similar to JPL-MPI demonstrate the effectiveness of the proposed algorithm for vibration control of space structures.
文摘Fracture of an ossification of the Achilles tendon(OAT)is a rare entity,and its etiology,pathology,and treatment remain unclear.We reviewed and scrutinized 18 cases(16 articles)of the fracture of an OAT.The most common etiologies of the ossifications include previous surgery and trauma.The fractures often occur without any trigger or with minimal trigger.The long,>5 cm,ossification in the body of the Achilles tendon may have a higher risk of fracture.The OAT itself is often asymptomatic;however,its fracture causes severe local pain,swelling,and weakness of plantar flexion,which forces patients to undergo aggressive treatments.Regarding the treatments of the fractures,nonoperative treatment by immobilizing ankle joint could be an option for elderly patients.However,because it often cannot produce satisfactory results in younger patients,surgical treatment is typically recommended.Excision of the fractured mass and repairing the tendon is applicable if the remnant is enough.If there is a defect after the excision,reconstruction with autologous grafts or adjacent tendon transfer is performed.Gastrocnemius fascia turndown flap,hamstring tendon and tensor fascia lata are used as autologous grafts,whereas peroneus brevis and flexor hallucis longus tendons are used for the tendon transfer.If the fracture of an OAT is treated properly,the functional result will be satisfactory.
文摘Tendon ruptures remain a significant musculoskeletal injury. Despite advances in surgical techniques and procedures, traditional repair techniques maintain a high incidence of rerupture or tendon elongation. Mechanical loading and biochemical signaling both control tissue healing. This has led some researchers to consider using a technique based on tension regulation at the suture line for obtaining good healing. However, it is unknown how they interact and to what extent mechanics control biochemistry. This review will open the way for understanding the interplay between mechanical loading and the process of tendon healing.
文摘BACKGROUND Injuries to the pectoralis major are infrequent,with only a few hundred cases currently recorded in the literature.CASE SUMMARY We report a case of a patient who sustained bilateral pectoralis major tendon ruptures.While other cases of bilateral pectoralis major tears have been reported in the literature,the operative management in this report differs.Due to delayed presentation of the patient right and left pectoralis major repairs were performed simultaneously.CONCLUSION Patients with delayed presentation of bilateral pectoralis major tendon ruptures can undergo simultaneous repair of both tendon with a good postoperative outcome and high patient satisfaction.
文摘Normal tendon substance is strong and is unlikely to break before the muscle origin, muscle, musculotendinous junction or the insertion yield. In almost all the cases, closed ruptures of the flexor tendon within the tendinous portion have been described in association with distinct underlying pathologies. We report a case of flexor tendon rupture of the index finger which seems to be associated with previous trauma occurred more than 40 years ago and abnormal healing.
基金Supported by Key Laboratory of Virus Disease Research of Zhuang Medicine in Guangxi University of Chinese Medicine(Gui Jiao Ke Yan[2022]No.10)The Key Discipline Zhuang Medicine Meridian Tendon Tuina of Traditional Chinese Medicine in Guangxi Zhuang Medicine(GZXK-Z-20-61)+1 种基金Gui School of Traditional Chinese Medicine Master Physician Project(Gui Zhong Yi Yao Ke Jiao Fa[2022]No.6)Research and Application of Key Techniques for Prevention and Treatment of Lumbago and Leg Pain in Zhuang Medicine(Guike AB21196035).
文摘Based on the understanding of lower limb numbness after stroke in Zhuang medicine, this study makes diagnosis and treatment of lower limb numbness after stroke from the clinical differentiation and treatment ideas of "numbness due to Shaoyang (lesser Yang)" through Zhuang Medicine Meridian Tendon Therapy. The triple therapy of meridian tendon Tuina+acupuncture+cupping originally created by Zhuang medicine and head bloodletting by Zhuang medicine were used to improve the numbness symptoms of patients. This provides a new thinking mode for acupuncture and moxibustion treatment of lower limb numbness after stroke.
文摘After corrosion failure of post-tensioned tendons was identified in a Florida bridge in early 2011, laboratory tests were conducted in this study on extracted sections from the failed tendons to identify the grout properties and makeup leading to the failure and also to elucidate the mechanism of corrosion. The initial steps in identification of PT tendons with a high propensity for corrosion initiation or damaged included a detailed visual inspection and identification of voids in the grout. Voids in tendon can be a result of bleed water formation or construction problems. General characteristics of the deficient grout and corrosion behavior of steel in the affected bridge gave a first approach to assessing grout deficiency and corrosion susceptibility. However, refinements in the understanding of the mechanisms causing grout segregation and the elucidation of the role of sulfates, oxygen content, and pore water pH in corrosion development are required.
文摘Prestressed concrete segmental box girder bridges are composed of short concrete segments that are either precast or cast in situ and then joined together by longitudinally post-tensioning internal,external,or mixed tendons.The objectives of this study are to monitor the construction process of the external prestressing tendons to strengthen the bridge structure and perform a field load test to measure the strain and the deflection of the anchorage devices of the external prestressing tendons to determine the state of these devices after tension forces are applied.The monitoring process of the external prestressing tendons construction includes inspecting the cracks in the diaphragm anchorage and the deviation block devices before the tension forces are applied to the external tendons;measuring the deformation of the steel deviation cross beam during the tension process;measuring the deformation of the box girder after different levels of tension forces are applied;measuring the elongation of the external tendons in each level of the tension;and measuring the natural frequency of the external tendons after the tension process is complete.The results of the monitoring process show that the measured values of the deformation,the elongation,and the natural frequency meet the requirements.Therefore,there is no damage during the construction and the tensioning of the external prestressing tendons.A field load test is performed to the anchorage beam,the steel deviation block devices,and the steel deviation cross beam.The field load test results of the anchorage devices show that the values of the strains,the stresses,and the deflection are less than the respective allowable limit values in the requirements.Therefore,the anchorage devices have sufficient strength,and the working state is good after the tension forces are applied to the external prestressing tendons.
文摘BACKGROUND Anterior cruciate ligament(ACL)reconstruction using bone-patellar tendon-bone(BPTB)autografts remains the gold standard for young,active individuals due to its superior biomechanical strength and bone-to-bone healing.However,donor site morbidity,particularly anterior knee pain(AKP),limits its utilization despite its advantages.Various techniques have been proposed to reduce AKP,but they show variable outcomes and several limitations.AIM To assess the incidence and severity of AKP following BPTB ACL reconstruction using an autologous bone grafting technique.METHODS We conducted a retrospective observational study of 24 patients aged 20-45 years,who had primary ACL reconstruction with BPTB grafts.During surgery,autologous cancellous bone generated from tunnel drilling was used to fill the patellar and tibial donor site voids after graft fixation.All patients were followed up for at least twelve months.Using the Kujala Anterior Knee Pain Score,clinical outcomes were evaluated,including the pain-specific subcomponent.RESULTS With scores ranging from 86 to 100,the average overall Kujala score was 95.67±4.01.No patient scored below 85.There was no complication such as patellar fracture,tibial tuberosity fracture,or infection.Grouped data showed 20.8%of patients scored 100,whereas 54.2%scored between 95 and 99,and 25%scored between 86 and 94.One patient(4.2%)had an 8/10 pain subcomponent,whereas 23 patients(95.8%)had a 10/10.CONCLUSION This procedure is easy to incorporate into routine surgical practice,cost-effective and reproducible without requiring extra incisions or raising the patient’s surgical expenses.Excellent short-term results back up this technique.
文摘Background It has been demonstrated that bone tunnel widening could appear after knee anterior cruciate ligament (ACL) reconstruction, especially for those patients whose ruptured ACL were reconstructed with semitendinosus and gracilis tendons. Many factors can influence the extent of tunnel widening. Few studies have investigated the relationship between bone tunnel widening and rehabilitation procedures. This research was carried out to find the rehabilitation procedures' influence on the tibial bone tunnel widening after ACL reconstruction. Methods Sixty-five cases, whose ACL reconstructions were done using quadrupled semitendinosus and gracilis tendons, were divided into two groups. Group A had 33 cases, 19 men, 14 women, averaged (31.2±12.4) years old, only ACL reconstruction was done using Paessler's technique, and aggressive rehabilitation procedure was used for function recovery post operation. Group B had 32 cases, 20 men, 12 women, averaged (30.3±10.3) years old. Except for ACL reconstruction, every patient in group B accepted meniscus repair using re-fixation methods or cartilage repair using microfracture technique, conservative rehabilitation procedure was used post operation. Six months post operation, standard posterior-anterior radiographic plates were taken for each case, CorelDRAW 8.0 software was used to digitize all X-ray plates and measure the upper, middle and lower parts of the tibial tunnel. Magnification effect of X-ray plates was taken out after measurement. Results Six months after ACL reconstruction the tibial tunnel widening of the upper, middle and lower parts on both the posterior-anterior and lateral X-ray plates in Group A with aggressive rehabilitation procedure was much more serious than in Group B with conservative rehabilitation. KT-1000 knee stability measurement and clinical manifestation showed no difference between the two groups. Conclusions Rehabilitation procedure after ACL reconstruction is one of the reasons for tunnel widening. It not only can directly influence the function recovery of ACL reconstructed knee, but also perhaps indirectly influence the function recovery and long-term clinical result of the operated knee by influencing the tunnel widening.
基金supported by the Department of Jobs,Tourism,Science and Innovation(JTSI),Government of Western Australia,through the Science Industry PhD Fellowship Program.
文摘Tendon and ligament(TL)injuries affect millions of people annually.Biopolymers play a significant role in TL tissue repair,whether the treatment relies on tissue engineering strategies or using artificial tendon grafts.The biopolymer governs the mechanical properties,biocompatibility,degradation,and fabrication method of the TL scaffold.Many natural,synthetic and hybrid biopolymers have been studied in TL regeneration,often combined with therapeutic agents and minerals to engineer novel scaffold systems.However,most of the advanced biopolymers have not advanced to clinical use yet.Here,we aim to review recent biopolymers and discuss their features for TL tissue engineering.After introducing the properties of the native tissue,we discuss different types of natural,synthetic and hybrid biopolymers used in TL tissue engineering.Then,we review biopolymers used in commercial absorbable and non-absorbable TL grafts.Finally,we explain the challenges and future directions for the development of novel biopolymers in TL regenerative treatment.
