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
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
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
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
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
Mechanical stress modulates bone formation and organization of the extracellular matrix(ECM),the interaction of which affects heterotopic ossification(HO).However,the mechanically sensitive cell populations in HO and ...Mechanical stress modulates bone formation and organization of the extracellular matrix(ECM),the interaction of which affects heterotopic ossification(HO).However,the mechanically sensitive cell populations in HO and the underlying mechanism remain elusive.Here,we show that the mechanical protein Polysyctin-1(PC1,Pkd1)regulates CTSK lineage tendon-derived mesenchymal stem cell(TDMSC)fate and ECM organization,thus affecting HO progression.First,we revealed that CTSK lineage TDMSCs are the major source of osteoblasts and fibroblasts in HO and are responsive to mechanical cues via single-cell RNA sequencing analysis and experiments with a lineage tracing mouse model.Moreover,we showed that PC1 mediates the mechanosignal transduction of CTSK lineage TDMSCs to regulate osteogenic and fibrogenic differentiation and alters the ECM architecture by facilitating TAZ nuclear translocation.Conditional gene depletion of Pkd1 or Taz in CTSK lineage cells and pharmaceutical intervention in the PC1-TAZ axis disrupt osteogenesis,fibrogenesis and ECM organization,and consequently attenuate HO progression.These findings suggest that mechanically sensitive CTSK-lineage TDMSCs contribute to heterotopic ossification through PC1-TAZ signaling axis mediated cell fate determination and ECM organization.展开更多
BACKGROUND Thumb replantation following complete traumatic avulsion requires complex techniques to restore function,especially in cases of avulsion at the level of the metacarpophalangeal joint(MCP I)and avulsion of t...BACKGROUND Thumb replantation following complete traumatic avulsion requires complex techniques to restore function,especially in cases of avulsion at the level of the metacarpophalangeal joint(MCP I)and avulsion of the flexor pollicis longus(FPL)at the musculotendinous junction.Possible treatments include direct tendon suture or tendon transfer,most commonly from the ring finger.To optimize function and avoid donor finger complications,we performed thumb replantation with flexion restoration using brachioradialis(BR)tendon transfer with palmaris longus(PL)tendon graft.CASE SUMMARY A 20-year-old left-handed male was admitted for a complete traumatic left thumb amputation following an accident while sliding from the top of a handrail.The patient presented with skin and bone avulsion at the MCP I,avulsion of the FPL tendon at the musculotendinous junction(zone 5),avulsion of the extensor pollicis longus tendon(zone T3),and avulsion of the thumb’s collateral arteries and nerves.The patient was treated with two stage thumb repair.The first intervention consisted of thumb replantation with MCP I arthrodesis,resection of avulsed FPL tendon and implantation of a silicone tendon prosthesis.The second intervention consisted of PL tendon graft and BR tendon transfer.Follow-up at 10 months showed good outcomes with active interphalangeal flexion of 70°,grip strength of 45 kg,key pinch strength of 15 kg and two-point discrimination threshold of 4 mm.CONCLUSION Flexion restoration after complete thumb amputation with FPL avulsion at the musculotendinous junction can be achieved using BR tendon transfer with PL tendon graft.展开更多
Tendon adhesion,a prevalent complication affecting over 30%of patients after a tendon injury or surgery,results in joint stiffness and impaired mobility.Although current treatments facilitate tendon repair,they are of...Tendon adhesion,a prevalent complication affecting over 30%of patients after a tendon injury or surgery,results in joint stiffness and impaired mobility.Although current treatments facilitate tendon repair,they are often insufficient in preventing adhesions and promoting optimal healing outcomes.To address these challenges,we developed an oriented cryostructured silk fibroin bandage(OCSFB)using the directional freeze-casting methodology.In vitro studies demonstrated that OCSFB provided a favorable microenvironment for cell viability,proliferation,and alignment,concurrently upregulating the expression of tendon-specific genes.In a rat Achilles tendon model,OCSFB significantly reduced adhesion formation and improved tendon healing.RNA-seq analysis further revealed modulation of cell adhesion molecules,substantiating its role in tissue regeneration.The integration of silk fibroin biocompatibility with a unique microstructure that facilitates cellular adhesion and proliferation renders OCSFB a promising approach for mitigating tendon adhesions and improving repair outcomes,establishing it as a robust candidate for clinical application.展开更多
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.
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.
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.
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.
基金National Natural Science Foundation of China(Grant Nos.82261160397,82272560)Central South University Research Programme of Advanced Interdisciplinary Studies(2023QYJC011)+4 种基金National Natural Science Foundation of China(Grant Nos.82472521,81922017)Hunan Provincial Science and Technology Department(2023JJ30896)Key Research and Development Program of Hunan Province(2022SK2023)Science and Technology Innovation Program of Hunan Province(2023RC1027)Major Basic Research Projects in Hunan Province(No.2024JC0004)。
文摘Mechanical stress modulates bone formation and organization of the extracellular matrix(ECM),the interaction of which affects heterotopic ossification(HO).However,the mechanically sensitive cell populations in HO and the underlying mechanism remain elusive.Here,we show that the mechanical protein Polysyctin-1(PC1,Pkd1)regulates CTSK lineage tendon-derived mesenchymal stem cell(TDMSC)fate and ECM organization,thus affecting HO progression.First,we revealed that CTSK lineage TDMSCs are the major source of osteoblasts and fibroblasts in HO and are responsive to mechanical cues via single-cell RNA sequencing analysis and experiments with a lineage tracing mouse model.Moreover,we showed that PC1 mediates the mechanosignal transduction of CTSK lineage TDMSCs to regulate osteogenic and fibrogenic differentiation and alters the ECM architecture by facilitating TAZ nuclear translocation.Conditional gene depletion of Pkd1 or Taz in CTSK lineage cells and pharmaceutical intervention in the PC1-TAZ axis disrupt osteogenesis,fibrogenesis and ECM organization,and consequently attenuate HO progression.These findings suggest that mechanically sensitive CTSK-lineage TDMSCs contribute to heterotopic ossification through PC1-TAZ signaling axis mediated cell fate determination and ECM organization.
文摘BACKGROUND Thumb replantation following complete traumatic avulsion requires complex techniques to restore function,especially in cases of avulsion at the level of the metacarpophalangeal joint(MCP I)and avulsion of the flexor pollicis longus(FPL)at the musculotendinous junction.Possible treatments include direct tendon suture or tendon transfer,most commonly from the ring finger.To optimize function and avoid donor finger complications,we performed thumb replantation with flexion restoration using brachioradialis(BR)tendon transfer with palmaris longus(PL)tendon graft.CASE SUMMARY A 20-year-old left-handed male was admitted for a complete traumatic left thumb amputation following an accident while sliding from the top of a handrail.The patient presented with skin and bone avulsion at the MCP I,avulsion of the FPL tendon at the musculotendinous junction(zone 5),avulsion of the extensor pollicis longus tendon(zone T3),and avulsion of the thumb’s collateral arteries and nerves.The patient was treated with two stage thumb repair.The first intervention consisted of thumb replantation with MCP I arthrodesis,resection of avulsed FPL tendon and implantation of a silicone tendon prosthesis.The second intervention consisted of PL tendon graft and BR tendon transfer.Follow-up at 10 months showed good outcomes with active interphalangeal flexion of 70°,grip strength of 45 kg,key pinch strength of 15 kg and two-point discrimination threshold of 4 mm.CONCLUSION Flexion restoration after complete thumb amputation with FPL avulsion at the musculotendinous junction can be achieved using BR tendon transfer with PL tendon graft.
基金sponsored by the National Natural Science Foundation of China(Nos.52235007,T2121004,and 52325504)the Key R&D Program of Zhejiang(No.2024SSYS0027)+1 种基金the National Key Research and Development Program of China(Nos.2024YFB4607700 and 2024YFB4607703)the China National Postdoctoral Program for Innovative Talents(No.BX20240312)。
文摘Tendon adhesion,a prevalent complication affecting over 30%of patients after a tendon injury or surgery,results in joint stiffness and impaired mobility.Although current treatments facilitate tendon repair,they are often insufficient in preventing adhesions and promoting optimal healing outcomes.To address these challenges,we developed an oriented cryostructured silk fibroin bandage(OCSFB)using the directional freeze-casting methodology.In vitro studies demonstrated that OCSFB provided a favorable microenvironment for cell viability,proliferation,and alignment,concurrently upregulating the expression of tendon-specific genes.In a rat Achilles tendon model,OCSFB significantly reduced adhesion formation and improved tendon healing.RNA-seq analysis further revealed modulation of cell adhesion molecules,substantiating its role in tissue regeneration.The integration of silk fibroin biocompatibility with a unique microstructure that facilitates cellular adhesion and proliferation renders OCSFB a promising approach for mitigating tendon adhesions and improving repair outcomes,establishing it as a robust candidate for clinical application.
