Anterior cruciate ligament(ACL)injuries are frequently caused by sports injuries and trauma.In cases involving complete tears,ACL reconstruction(ACLR)surgery is the only way to restore the ligament’s integrity.When s...Anterior cruciate ligament(ACL)injuries are frequently caused by sports injuries and trauma.In cases involving complete tears,ACL reconstruction(ACLR)surgery is the only way to restore the ligament’s integrity.When selecting a graft,both the potential complications and the mechanical properties and healing efficacies should be considered.Artificial ligaments have been widely applied in clinical ACLR,and most have exhibited satisfactory biocompatibility and short-term follow-up results.Compared with autografts and allografts,however,the lack of bioactivity of currently available artificial ligaments is a major disadvantage.In addition,some long-term follow-up results have revealed other drawbacks of artificial ligaments,such as graft failure and other complications.Here,we summarize attempts to enhance the bioactive performance of artificial ligaments,as such modifications may have good potential for clinical translation and could improve the long-term outcomes of existing products.展开更多
Ligament cryopreservation enables a prolonged shelf life of allogeneic ligament grafts,which is fundamentally important to ligament reconstruction.However,conventional cryopreservation techniques fail to eliminate the...Ligament cryopreservation enables a prolonged shelf life of allogeneic ligament grafts,which is fundamentally important to ligament reconstruction.However,conventional cryopreservation techniques fail to eliminate the damage caused by ice crystal growth and the toxicity of cryopreservation agents(CPAs).Here,we report a novel CPA vitrification formulation primarily composed of betaine for ligament cryopreservation.Comprehensive optimization was conducted on the methods for vitrification and rewarming,as well as the loading and unloading conditions,based on the critical cooling rate(CCR),critical warming rate(CWR),and permeation properties of the CPA.Using biomechanical and histological level tests,we demonstrate the superior performance of our method in ligament cryopreservation.After 30 days of vitrification cryopreservation,parameters such as the Young's modulus,tensile stress,denaturation temperature,and glycosaminoglycans content of the ligament remained essentially unchanged.This work pioneers the application of ice-free cryopreservation for ligament and holds great potential for improving the long-term storage of ligament,providing valuable insights for future cryopreservation technique development.展开更多
Objective:Pelvic organ prolapse(POP)is a common condition in postmenopausal women,with an increasing prevalence due to aging.Some women experience POP recurrence after surgical treatment,significantly affecting their ...Objective:Pelvic organ prolapse(POP)is a common condition in postmenopausal women,with an increasing prevalence due to aging.Some women experience POP recurrence after surgical treatment,significantly affecting their physical and mental health.The uterosacral ligament is a critical pelvic support structure.This study aims to investigate the molecular pathological changes in the uterosacral ligament of postmenopausal women with recurrent POP using transcriptomic analysis.Methods:Transcriptomic data of uterosacral ligament tissues were obtained from the public dataset GSE28660,which includes samples from 4 postmenopausal women with recurrent POP,4 with primary POP,and 4 without POP.Differentially expressed genes(DEGs)were identified between recurrent POP and both primary and non-POP groups.Further analysis included intersection analysis of DEGs,gene ontology enrichment,protein protein interaction(PPI)network construction,gene set enrichment analysis(GSEA),single-sample GSEA,and xCell immune cell infiltration analysis to explore molecular pathological changes in recurrent POP.Additionally,histological and molecular differences in the uterosacral ligament were compared between simulated vaginal delivery(SVD)rat models with and without ovariectomy.Results:Compared with primary POP and non-POP groups,recurrent POP exhibited activation of adipogenesis and inflammation-related pathways,while pathways related to muscle proliferation and contraction were downregulated in the uterosacral ligament.Nine key DEGs(ADIPOQ,FABP4,IL-6,LIPE,LPL,PCK1,PLIN1,PPARG,and CD36)were identified,with most enriched in the peroxisome proliferator-activated receptor(PPAR)signaling pathway.These genes were significantly correlated with lipid accumulation,monocyte infiltration,and neutrophil infiltration in the uterosacral ligament.Urodynamic testing revealed that the bladder leak point pressure was significantly higher in ovariectomized SVD rats,both of which had higher values than the sham group.Masson staining showed pronounced adipogenesis in the uterosacral ligament of ovariectomized SVD rats,along with reduced collagen and muscle fibers compared to the sham and non ovariectomized SVD groups.Furthermore,real-time RT-PCR confirmed significantly elevated expression of key DEGs,including ADIPOQ,IL-6,PCK1,and PLIN1,in the uterosacral ligaments of ovariectomized SVD rats.Conclusion:Adipogenesis and inflammation in the uterosacral ligament may contribute to its reduced supportive function,potentially leading to recurrence POP in postmenopausal women.展开更多
The existence and composition of the lateral ligaments of the rectum (LLR) are still the subjects of anatomical confusion and surgical misconception up to now. Since Miles proposed abdominoperineal excision as radical...The existence and composition of the lateral ligaments of the rectum (LLR) are still the subjects of anatomical confusion and surgical misconception up to now. Since Miles proposed abdominoperineal excision as radical surgery for rectal cancer, the identification by "hooking them on the finger" has been accepted by many surgeons with no doubt; clamping, dividing and ligating are considered to be essential procedures in mobilization of the rectum in many surgical textbooks. But in cadaveric studies, many anatomists could not find LLR described by the textbooks, and more and more surgeons also failed to find LLR during the proctectomy according to the principle of total mesorectal excision. The anatomy of LLR has diverse descriptions in literatures. According to our clinical observations, the traditional anatomical structures of LLR do exist; LLR are constant dense connective bundles which are located in either lateral side of the lower part of the rectum, run between rectal visceral fascia and pelvic parietal fascia above the levator ani, and covered by superior fascia of pelvic diaphragm. They are pathways of blood vessels and nerve fibers toward the rectum and lymphatic vessels from the lower rectum toward the iliac lymph nodes.展开更多
Chiral honeycomb structures have been developed in recent years, showing excellent mechanical properties, including in-plane deformation and out-of-plane bearing and vibration isolation. In this study, the 65Mn chiral...Chiral honeycomb structures have been developed in recent years, showing excellent mechanical properties, including in-plane deformation and out-of-plane bearing and vibration isolation. In this study, the 65Mn chiral structure with three ligaments was modeled and analyzed using the finite element (FE) method. The effects of the dimensionless ligament length and dimensionless ligament thickness on the in-plane equivalent elastic modulus, equivalent Poisson's ratio, and out-of-plane shear modulus were studied. The numerical results indicate that increase of the dimensionless ligament length leads to decrease of the equivalent elastic modulus and increase of the equivalePoisson's ratio, whereas the out-of-plane equivalent shear modulus decreases. The results also indicate that increase of the dimensionless ligament thickness leads to in crease of the equivalent elastic modulus, whereas the equivalent Poisson's ratio remains nearly unchanged and the out-of-plane equivalent shear modulus shows a linear in crease. The numerical results are verified by comparis on with published experime ntal data. These results will provide a reference for the application of chiral structures with three ligaments in the aerospace field.展开更多
This paper establishes a non-linear finite element model (NFEM) of L4-L5 lumbar spinal segment with accurate three-dimensional solid ligaments and intervertebral disc. For the purpose, the intervertebral disc and surr...This paper establishes a non-linear finite element model (NFEM) of L4-L5 lumbar spinal segment with accurate three-dimensional solid ligaments and intervertebral disc. For the purpose, the intervertebral disc and surrounding ligaments are modeled with four-nodal three-dimensional tetrahedral elements with hyper-elastic material properties. Pure moment of 10 N·m without preload is applied to the upper vertebral body under the loading conditions of lateral bending, backward extension, torsion, and forward flexion, respectively. The simulate relationship curves between generalized forces and generalized displacement of the NFEM are compared with the in vitro experimental result curves to verify NFEM. The verified results show that: (1) The range of simulated motion is a good agreement with the in vitro experimental data; (2) The NFEM can more effectively reffect the actual mechanical properties than the FE model using cable and spring elements ligaments; (3) The NFEM can be used as the basis for further research on lumbar degenerative diseases.展开更多
The worldwide prevalence of spinal cord injury （SCI） ranges from 233 to 755 per million inhabitants, whereas the report- ed incidence lies between 10.4 and 83 per million inhabitants annually （Wyndaele and Wyndaele...The worldwide prevalence of spinal cord injury （SCI） ranges from 233 to 755 per million inhabitants, whereas the report- ed incidence lies between 10.4 and 83 per million inhabitants annually （Wyndaele and Wyndaele, 2006）. Thus, the socio- economic impact of SCI associated with cervical trauma is high enough that it could become an important concern in the vast majority of developed countries.展开更多
For designing efficient lubrication system of an aeroengine bearing chamber,sufficient knowledge on oil/air two-phase flow characteristics is required.When analyzing bearing chamber two-phase flow,the essential prereq...For designing efficient lubrication system of an aeroengine bearing chamber,sufficient knowledge on oil/air two-phase flow characteristics is required.When analyzing bearing chamber two-phase flow,the essential prerequisite is quantifying the oil ligaments,which are detached from bearing rotary elements and shed into the bearing chamber.Related investigations are mainly targeted at liquid shedding on the rotating disk as opposed to the bearing rotary elements.Moreover,the research based on bearing rotary elements is conducted by experiment.Due to the limited operating conditions,experimental studies cannot guide engineering applications.To overcome these limitations,a theoretical model is established in this paper,for revealing the mechanism of oil shedding from bearing rotary elements and quantifying the shedding ligaments.The theoretical model is validated against experimental results from classical studies.In addition,the correlation for shedding ligaments number based on aeroengine bearing structural and operational parameters is obtained via theoretical analysis.The analytical results demonstrate that oil shedding and ligaments formation appear at the edge of bearing inner race outer-periphery.The number of shedding ligaments increases with the rise of shaft rotational speed while decreases with the growth of oil viscosity.展开更多
The lumbar ligaments play an important role in spinal biomechanics.The results ofthree-dimensional finite dement analysis showed that one of the functions of lumbar ligaments istransmission of the tensile load between...The lumbar ligaments play an important role in spinal biomechanics.The results ofthree-dimensional finite dement analysis showed that one of the functions of lumbar ligaments istransmission of the tensile load between the lumbar vertebrae.The anterior longitudinal ligament isloaded in extension of lumbar spine and the resistance to the tensile load in flexion is providedby other ligaments.These ligaments are subject to much more tension with degeneration of theintervertebral disc so that a series of pathological changes occur.Relevant significance in clinical as-pect is also discussed.展开更多
Purpose: The assessment of the morphology and dimensions of the craniocervical ligaments using a 3 Tesla (T) Magnetic Resonance (MR) scanner, the correlatation of our results with those from cadaveric and other MR stu...Purpose: The assessment of the morphology and dimensions of the craniocervical ligaments using a 3 Tesla (T) Magnetic Resonance (MR) scanner, the correlatation of our results with those from cadaveric and other MR studies and the detection of the most appropriate sequence for the best imaging of the craniovertebral junction ligaments. Methods: 58 healthy volunteers (mean age 45 years) underwent a Magnetic Resonance Imaging (MRI) of the cervical spine at 3T MR unit. The MRI protocol included axial, coronal and sagittal Proton-Density (PD) sequences and sagittal T1 Fluid Attenuated Inversion Recovery (FLAIR) and T2 sequences. The images were evaluated by two radiologists and the posterior atlantoocipital ligament, the anterior atlantoocipital ligament, the transverse ligament and the apical ligament were anatomically detected, described and measured. Results: The transverse ligament was identified at 93.1%, the apical ligament was identified at 60.34%, the posterior at- lantooccipital membrane was identified at 94.8% and the anterior atlantooccipital membrane was identified at 96.5% of the cases. All ligaments appeared with low signal intensity, except the anterior atlantooc-cipital ligament which appeared with intermediate signal intensity. Their length, width and thickness were measured and, in general, correlated well with other anatomic and MR studies. Conclusion: Reliable assessment of the morphology and signal intensity of the craniocervical ligaments can be achieved with PD sequence at 3T MR imaging. The sagittal plane provides better delineation of the craniocervical (CC) ligaments but the axial and coronal planes are of paramount importance in the assessment of the transverse and apical ligaments.展开更多
BACKGROUND Patellar tendon rupture is a rare disease,and reports regarding patellar tendon reconstruction with ligament augmentation reconstruction system(LARS)ligaments are limited,with only three reports available i...BACKGROUND Patellar tendon rupture is a rare disease,and reports regarding patellar tendon reconstruction with ligament augmentation reconstruction system(LARS)ligaments are limited,with only three reports available in the literature.LARS ligaments are made of polyethylene terephthalate and have been certified as a more favorable option than other tendon transplants.To our knowledge,this is the first report of patellar tendon reconstruction with LARS for suture fixation due to poor quality of the tendon after multiple operations to enable early mobilization and quick rehabilitation.CASE SUMMARY A 65-year-old woman had limited ability in extending her leg and an inability to perform a straight leg raise after multiple operations due to patella fracture.The patient underwent patellar tendon reconstruction with LARS artificial ligaments.After 12 mo of follow-up,the patient was able to perform a straight leg raise,and the incision healed well without complications.The Lysholmscore was 95 and the range of motion of the knee was 0-130°.CONCLUSION This study revealed that patellar tendon reconstruction with LARS artificial ligaments is possible in a patient with a patellar tendon rupture who required rapid postoperative recovery.展开更多
Accurate representation of soft tissue material properties plays a crucial role in computational biomechanics. Several material models have been used for knee ligaments in finite element (FE) studies, including the ne...Accurate representation of soft tissue material properties plays a crucial role in computational biomechanics. Several material models have been used for knee ligaments in finite element (FE) studies, including the neo-Hookean model (widely used) and the Holzapfel-Gasser-Ogden (HGO) model (seldom used). While the coefficients of neo-Hookean models for the knee ligaments are available in the literature, limited data exists for the HGO model. Furthermore, no peer-reviewed comparison of these two material models for the knee ligaments while including the 3D representation of the ligaments for both material models is present in the literature. We used mechanical properties from the tensile test experiments in the literature for each ligament to obtain the HGO material coefficients while accounting for the ligaments’ viscoelastic behavior. Resultant coefficients were then used in an Abaqus/explicit knee model to simulate bipedal landing from a jump. The simulations were repeated with neo-Hookean values from the literature. Knee kinematics plus ACL and MCL strains were evaluated and compared for these two material models. The outputs from the simulations with HGO properties were predominantly within 1.5 standard deviations from the mean in-vitro data. When the material properties changed to Neo-Hookean, the outputs for kinematics and strain values were higher than the HGO case, and in most instances, they were outside the experimental range for ACL and MCL strains (by up to 11.35 SD) as well as some ITR angles (by up to 2.86 SD). Reported HGO material model with optimized coefficients produces a more realistic representation of the ligaments’ material properties, and will help improve the outcomes of FE models for more accurate predictions of knee behavior.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
BACKGROUND Recently,the use of ligament advanced reinforcement system(LARS)artificial ligament,a new graft which has several unique advantages such as no donor-site morbidity,early recovery and no risk of disease tran...BACKGROUND Recently,the use of ligament advanced reinforcement system(LARS)artificial ligament,a new graft which has several unique advantages such as no donor-site morbidity,early recovery and no risk of disease transmission which has been a significant breakthrough for anatomical ligament reconstruction.Growing studies suggested that the special design of the LARS ligament with open fibers in its intra-articular part was believed to be more resistant to torsional fatigue and wearing.However,the safety and efficacy of LARS artificial ligament for ankle joint lateral collateral ankle ligament reconstruction has not been defined to date.AIM To evaluate the clinical results of all-arthroscopic anatomical reconstruction of ankle joint lateral collateral ligaments with the LARS artificial ligament for chronic ankle instability.METHODS Twenty-two patients with chronic lateral instability underwent anatomical reconstruction of the lateral collateral ligaments of ankle with LARS artificial ligament.The visual analogue score(VAS),American Orthopaedic Foot and Ankle Society score(AOFAS score)and Karlsson score were used to evaluate the clinical results before and after surgery.RESULTS A total of 22 patients(22 ankles)were followed up for a mean of 12 mo.All patients reported significant improvement compared to their preoperative status.The mean AOFAS score improved from 42.3±4.9 preoperatively to 90.4±6.7 postoperatively.The mean Karlsson score improved from 38.5±3.2 preoperatively to 90.1±7.8 postoperatively.The mean VAS score improved from 1.9±2.5 preoperatively to 0.8±1.7 postoperatively.CONCLUSION All-arthroscopic anatomical reconstruction of the lateral collateral ligaments with LARS artificial ligament achieved a satisfactory surgical outcome for chronic ankle instability.展开更多
Design of artificial ligaments possessing both osteogenic activity and antibacterial effect that promotes ligament-bone healing and prevents bacterial infection in bone tunnels for anterior cruciate ligament(ACL)recon...Design of artificial ligaments possessing both osteogenic activity and antibacterial effect that promotes ligament-bone healing and prevents bacterial infection in bone tunnels for anterior cruciate ligament(ACL)reconstruction remains a significant challenge.In this study,black tantalic oxide(BTO)submicro-particles with oxygen vacancies and structure defects were fabricated by using traditional white tan-talic oxide(WTO)through magnesium thermal reduction(MTR)method,and BTO was coated on polyetheretherketone(PEEK)fibers(PKF),which were woven into fabrics(PBT)as artificial ligaments.PBT with BTO coating exhibited excellent photothermal performance,which possessed not only antibac-terial effects in vitro but also anti-infective ability in vivo.PBT with optimized surface properties(e.g.,submicro-topography and hydrophilicity)not only significantly facilitated rat bone mesenchymal stem cells(BMSC)responses(e.g.,proliferation and osteogenic differentiation)in vitro but also stimulated new bone formation for ligament-bone healing in vivo.The presence of oxygen vacancies and structure de-fects in BTO did not change the surface properties and osteogenic activity of BPT while displaying an outstanding photothermal antibacterial effect.In summary,BPT with osteogenic activity and photother-mal antibacterial effect promoted bone regeneration and prevented bacterial infection,thereby promoting ligament-bone healing.Therefore,PBT would have tremendous potential as a novel artificial ligament for ACL reconstruction.展开更多
To quantify mechanical effects of plantar fascia and ligaments on the arch structure,a 3D finite element model of the foot was created to simulate the balanced standing posture. Four cases after individual releases of...To quantify mechanical effects of plantar fascia and ligaments on the arch structure,a 3D finite element model of the foot was created to simulate the balanced standing posture. Four cases after individual releases of plantar fascia,spring ligament,long and short plantar ligaments were simulated respectively to compare their consequences to the predictions of the intact structure. It was founded that the foot arch didn't collapse obviously after any individual release of these structures. As plantar fascia was released,tensions of plantar ligaments were largely increased. Long and short plantar ligaments performed mutual compensation functions.展开更多
BACKGROUND Hypoplasia of bilateral cruciate ligaments is a rare congenital malformation.The diagnosis of such diseases and indications for the various treatment options require further analysis and discussion.CASE SUM...BACKGROUND Hypoplasia of bilateral cruciate ligaments is a rare congenital malformation.The diagnosis of such diseases and indications for the various treatment options require further analysis and discussion.CASE SUMMARY The patient is a 26-year-old Chinese woman who has been suffering from knee pain since the age of 8 years,2-3 episodes a year.Three years ago,due to the practice of advanced yoga poses,the frequency of left knee pain increased,requiring prompt medical treatment.Magnetic resonance imaging demonstrated an absence of both anterior and posterior cruciate ligaments of both knees with abnormal posterior tilting of the tibial plateau.Bilateral subluxation of the knee joint was also found,therefore tibial osteotomy was performed.The patient reported at the 24 mo follow-up that the frequency of pain and instability had been reduced and function restored.CONCLUSION Osteotomy may be an effective method to treat patients with congenital cruciate ligament deficiency with posterior tibial plateau tilting.The diagnosis of congenital cruciate ligament deficiency shall be based on the combination of patient’s medical history,clinical manifestations,and findings from imaging to avoid possible misdiagnosis.Based on the symptoms,frequency of attacks,and intent of the individual,appropriate treatment options shall be identified.展开更多
A stress analysis is described for a nuclear steam generator tubesheet with a thin, or irregular ligament, associated with a mis-drilled hole using the rules of ASME （American Society of Mechanical Engineers） B ＆ P...A stress analysis is described for a nuclear steam generator tubesheet with a thin, or irregular ligament, associated with a mis-drilled hole using the rules of ASME （American Society of Mechanical Engineers） B ＆ PV Section Ⅲ and non-mandatory Appendix A, Article A-8000 for stresses in perforated flat plates. The analysis demonstrates the proper application of the NB-3200 rules for this special application, with discussion of the differences between an actual tube hole deviation and what is assumed in ASME Appendix A. This is a companion paper to ＂Technical Justification Supporting Operation with a Tube Installed in a Mis-Drilled Hole of a Steam Generator Tubesheet＂.展开更多
The global rise in anterior cruciate ligament(ACL)injuries underscores the urgent need for high-performance artificial ligaments.However,long-term clinical use is still challenged by fabric structure disintegration,ru...The global rise in anterior cruciate ligament(ACL)injuries underscores the urgent need for high-performance artificial ligaments.However,long-term clinical use is still challenged by fabric structure disintegration,rupture,and pull-out failure.This study presents a straightforward strategy to enhance mechanical performance through knitted structural design,addressing the research gap between ligament architecture and pull-out resistance.A mathematical model was established to correlate structural parameters with the maximum pull-out force,guiding the optimization of the artificial ligament based on key mechanical properties.Furthermore,the interaction between the artificial ligament and the bone tunnel was analyzed using a mechanical ACL model.By varying the wales of underlapping per course from 2 to 5,the pull-out force of individual weft insertion yarns improved by up to 118.16%.The optimized ligament achieved a breaking strength close to 7000 N,approximately 40%higher than that of conventional designs,and exhibited an 18.85%reduction in fatigue deformation.In addition,it significantly enhanced the pull-out resistance of the bone tunnel.These findings provide valuable insights into improving the durability and structural reliability of other knitted biomedical implants.展开更多
基金supported by the Areas of Excellence Scheme(AoE/M402/20)the Knowledge Transfer Project Fund(KPF24GWP05)+2 种基金the IdeaBooster Fund(IDBF24MED12)the HKSTP Ideation Fund(Ideation 23-0698)the ITC Technology Startup Support Scheme for Universities(TSU24MED05).
文摘Anterior cruciate ligament(ACL)injuries are frequently caused by sports injuries and trauma.In cases involving complete tears,ACL reconstruction(ACLR)surgery is the only way to restore the ligament’s integrity.When selecting a graft,both the potential complications and the mechanical properties and healing efficacies should be considered.Artificial ligaments have been widely applied in clinical ACLR,and most have exhibited satisfactory biocompatibility and short-term follow-up results.Compared with autografts and allografts,however,the lack of bioactivity of currently available artificial ligaments is a major disadvantage.In addition,some long-term follow-up results have revealed other drawbacks of artificial ligaments,such as graft failure and other complications.Here,we summarize attempts to enhance the bioactive performance of artificial ligaments,as such modifications may have good potential for clinical translation and could improve the long-term outcomes of existing products.
基金supported by the National Natural Science Foundation of China(22078238,U23B20121)。
文摘Ligament cryopreservation enables a prolonged shelf life of allogeneic ligament grafts,which is fundamentally important to ligament reconstruction.However,conventional cryopreservation techniques fail to eliminate the damage caused by ice crystal growth and the toxicity of cryopreservation agents(CPAs).Here,we report a novel CPA vitrification formulation primarily composed of betaine for ligament cryopreservation.Comprehensive optimization was conducted on the methods for vitrification and rewarming,as well as the loading and unloading conditions,based on the critical cooling rate(CCR),critical warming rate(CWR),and permeation properties of the CPA.Using biomechanical and histological level tests,we demonstrate the superior performance of our method in ligament cryopreservation.After 30 days of vitrification cryopreservation,parameters such as the Young's modulus,tensile stress,denaturation temperature,and glycosaminoglycans content of the ligament remained essentially unchanged.This work pioneers the application of ice-free cryopreservation for ligament and holds great potential for improving the long-term storage of ligament,providing valuable insights for future cryopreservation technique development.
基金supported by the Key Research and Development Program of Hunan Province(2023SK2038)the Natural Science Foundation of Hunan Province(2024JJ8121),China。
文摘Objective:Pelvic organ prolapse(POP)is a common condition in postmenopausal women,with an increasing prevalence due to aging.Some women experience POP recurrence after surgical treatment,significantly affecting their physical and mental health.The uterosacral ligament is a critical pelvic support structure.This study aims to investigate the molecular pathological changes in the uterosacral ligament of postmenopausal women with recurrent POP using transcriptomic analysis.Methods:Transcriptomic data of uterosacral ligament tissues were obtained from the public dataset GSE28660,which includes samples from 4 postmenopausal women with recurrent POP,4 with primary POP,and 4 without POP.Differentially expressed genes(DEGs)were identified between recurrent POP and both primary and non-POP groups.Further analysis included intersection analysis of DEGs,gene ontology enrichment,protein protein interaction(PPI)network construction,gene set enrichment analysis(GSEA),single-sample GSEA,and xCell immune cell infiltration analysis to explore molecular pathological changes in recurrent POP.Additionally,histological and molecular differences in the uterosacral ligament were compared between simulated vaginal delivery(SVD)rat models with and without ovariectomy.Results:Compared with primary POP and non-POP groups,recurrent POP exhibited activation of adipogenesis and inflammation-related pathways,while pathways related to muscle proliferation and contraction were downregulated in the uterosacral ligament.Nine key DEGs(ADIPOQ,FABP4,IL-6,LIPE,LPL,PCK1,PLIN1,PPARG,and CD36)were identified,with most enriched in the peroxisome proliferator-activated receptor(PPAR)signaling pathway.These genes were significantly correlated with lipid accumulation,monocyte infiltration,and neutrophil infiltration in the uterosacral ligament.Urodynamic testing revealed that the bladder leak point pressure was significantly higher in ovariectomized SVD rats,both of which had higher values than the sham group.Masson staining showed pronounced adipogenesis in the uterosacral ligament of ovariectomized SVD rats,along with reduced collagen and muscle fibers compared to the sham and non ovariectomized SVD groups.Furthermore,real-time RT-PCR confirmed significantly elevated expression of key DEGs,including ADIPOQ,IL-6,PCK1,and PLIN1,in the uterosacral ligaments of ovariectomized SVD rats.Conclusion:Adipogenesis and inflammation in the uterosacral ligament may contribute to its reduced supportive function,potentially leading to recurrence POP in postmenopausal women.
文摘The existence and composition of the lateral ligaments of the rectum (LLR) are still the subjects of anatomical confusion and surgical misconception up to now. Since Miles proposed abdominoperineal excision as radical surgery for rectal cancer, the identification by "hooking them on the finger" has been accepted by many surgeons with no doubt; clamping, dividing and ligating are considered to be essential procedures in mobilization of the rectum in many surgical textbooks. But in cadaveric studies, many anatomists could not find LLR described by the textbooks, and more and more surgeons also failed to find LLR during the proctectomy according to the principle of total mesorectal excision. The anatomy of LLR has diverse descriptions in literatures. According to our clinical observations, the traditional anatomical structures of LLR do exist; LLR are constant dense connective bundles which are located in either lateral side of the lower part of the rectum, run between rectal visceral fascia and pelvic parietal fascia above the levator ani, and covered by superior fascia of pelvic diaphragm. They are pathways of blood vessels and nerve fibers toward the rectum and lymphatic vessels from the lower rectum toward the iliac lymph nodes.
文摘Chiral honeycomb structures have been developed in recent years, showing excellent mechanical properties, including in-plane deformation and out-of-plane bearing and vibration isolation. In this study, the 65Mn chiral structure with three ligaments was modeled and analyzed using the finite element (FE) method. The effects of the dimensionless ligament length and dimensionless ligament thickness on the in-plane equivalent elastic modulus, equivalent Poisson's ratio, and out-of-plane shear modulus were studied. The numerical results indicate that increase of the dimensionless ligament length leads to decrease of the equivalent elastic modulus and increase of the equivalePoisson's ratio, whereas the out-of-plane equivalent shear modulus decreases. The results also indicate that increase of the dimensionless ligament thickness leads to in crease of the equivalent elastic modulus, whereas the equivalent Poisson's ratio remains nearly unchanged and the out-of-plane equivalent shear modulus shows a linear in crease. The numerical results are verified by comparis on with published experime ntal data. These results will provide a reference for the application of chiral structures with three ligaments in the aerospace field.
基金supported by the National Natural Science Foundation of China (10832012, 10872078 and10972090)Scientific Advancing Front and Interdiscipline Innovation Project of Jilin University (200903169)
文摘This paper establishes a non-linear finite element model (NFEM) of L4-L5 lumbar spinal segment with accurate three-dimensional solid ligaments and intervertebral disc. For the purpose, the intervertebral disc and surrounding ligaments are modeled with four-nodal three-dimensional tetrahedral elements with hyper-elastic material properties. Pure moment of 10 N·m without preload is applied to the upper vertebral body under the loading conditions of lateral bending, backward extension, torsion, and forward flexion, respectively. The simulate relationship curves between generalized forces and generalized displacement of the NFEM are compared with the in vitro experimental result curves to verify NFEM. The verified results show that: (1) The range of simulated motion is a good agreement with the in vitro experimental data; (2) The NFEM can more effectively reffect the actual mechanical properties than the FE model using cable and spring elements ligaments; (3) The NFEM can be used as the basis for further research on lumbar degenerative diseases.
文摘The worldwide prevalence of spinal cord injury （SCI） ranges from 233 to 755 per million inhabitants, whereas the report- ed incidence lies between 10.4 and 83 per million inhabitants annually （Wyndaele and Wyndaele, 2006）. Thus, the socio- economic impact of SCI associated with cervical trauma is high enough that it could become an important concern in the vast majority of developed countries.
基金supported by the National Science and Technology Major Project(No.J2019-Ⅲ-0023-0067)the National Natural Science Foundation of China(No.51975475)the Fundamental Research funds for the Central Universities(No.31020200503002)。
文摘For designing efficient lubrication system of an aeroengine bearing chamber,sufficient knowledge on oil/air two-phase flow characteristics is required.When analyzing bearing chamber two-phase flow,the essential prerequisite is quantifying the oil ligaments,which are detached from bearing rotary elements and shed into the bearing chamber.Related investigations are mainly targeted at liquid shedding on the rotating disk as opposed to the bearing rotary elements.Moreover,the research based on bearing rotary elements is conducted by experiment.Due to the limited operating conditions,experimental studies cannot guide engineering applications.To overcome these limitations,a theoretical model is established in this paper,for revealing the mechanism of oil shedding from bearing rotary elements and quantifying the shedding ligaments.The theoretical model is validated against experimental results from classical studies.In addition,the correlation for shedding ligaments number based on aeroengine bearing structural and operational parameters is obtained via theoretical analysis.The analytical results demonstrate that oil shedding and ligaments formation appear at the edge of bearing inner race outer-periphery.The number of shedding ligaments increases with the rise of shaft rotational speed while decreases with the growth of oil viscosity.
基金The project was supported by the National Natura Science Foundation of China
文摘The lumbar ligaments play an important role in spinal biomechanics.The results ofthree-dimensional finite dement analysis showed that one of the functions of lumbar ligaments istransmission of the tensile load between the lumbar vertebrae.The anterior longitudinal ligament isloaded in extension of lumbar spine and the resistance to the tensile load in flexion is providedby other ligaments.These ligaments are subject to much more tension with degeneration of theintervertebral disc so that a series of pathological changes occur.Relevant significance in clinical as-pect is also discussed.
文摘Purpose: The assessment of the morphology and dimensions of the craniocervical ligaments using a 3 Tesla (T) Magnetic Resonance (MR) scanner, the correlatation of our results with those from cadaveric and other MR studies and the detection of the most appropriate sequence for the best imaging of the craniovertebral junction ligaments. Methods: 58 healthy volunteers (mean age 45 years) underwent a Magnetic Resonance Imaging (MRI) of the cervical spine at 3T MR unit. The MRI protocol included axial, coronal and sagittal Proton-Density (PD) sequences and sagittal T1 Fluid Attenuated Inversion Recovery (FLAIR) and T2 sequences. The images were evaluated by two radiologists and the posterior atlantoocipital ligament, the anterior atlantoocipital ligament, the transverse ligament and the apical ligament were anatomically detected, described and measured. Results: The transverse ligament was identified at 93.1%, the apical ligament was identified at 60.34%, the posterior at- lantooccipital membrane was identified at 94.8% and the anterior atlantooccipital membrane was identified at 96.5% of the cases. All ligaments appeared with low signal intensity, except the anterior atlantooc-cipital ligament which appeared with intermediate signal intensity. Their length, width and thickness were measured and, in general, correlated well with other anatomic and MR studies. Conclusion: Reliable assessment of the morphology and signal intensity of the craniocervical ligaments can be achieved with PD sequence at 3T MR imaging. The sagittal plane provides better delineation of the craniocervical (CC) ligaments but the axial and coronal planes are of paramount importance in the assessment of the transverse and apical ligaments.
基金Supported by National Natural Science Foundation of China,No.81871814Natural Science Foundation of Shandong Province,No.ZR2017MH119
文摘BACKGROUND Patellar tendon rupture is a rare disease,and reports regarding patellar tendon reconstruction with ligament augmentation reconstruction system(LARS)ligaments are limited,with only three reports available in the literature.LARS ligaments are made of polyethylene terephthalate and have been certified as a more favorable option than other tendon transplants.To our knowledge,this is the first report of patellar tendon reconstruction with LARS for suture fixation due to poor quality of the tendon after multiple operations to enable early mobilization and quick rehabilitation.CASE SUMMARY A 65-year-old woman had limited ability in extending her leg and an inability to perform a straight leg raise after multiple operations due to patella fracture.The patient underwent patellar tendon reconstruction with LARS artificial ligaments.After 12 mo of follow-up,the patient was able to perform a straight leg raise,and the incision healed well without complications.The Lysholmscore was 95 and the range of motion of the knee was 0-130°.CONCLUSION This study revealed that patellar tendon reconstruction with LARS artificial ligaments is possible in a patient with a patellar tendon rupture who required rapid postoperative recovery.
文摘Accurate representation of soft tissue material properties plays a crucial role in computational biomechanics. Several material models have been used for knee ligaments in finite element (FE) studies, including the neo-Hookean model (widely used) and the Holzapfel-Gasser-Ogden (HGO) model (seldom used). While the coefficients of neo-Hookean models for the knee ligaments are available in the literature, limited data exists for the HGO model. Furthermore, no peer-reviewed comparison of these two material models for the knee ligaments while including the 3D representation of the ligaments for both material models is present in the literature. We used mechanical properties from the tensile test experiments in the literature for each ligament to obtain the HGO material coefficients while accounting for the ligaments’ viscoelastic behavior. Resultant coefficients were then used in an Abaqus/explicit knee model to simulate bipedal landing from a jump. The simulations were repeated with neo-Hookean values from the literature. Knee kinematics plus ACL and MCL strains were evaluated and compared for these two material models. The outputs from the simulations with HGO properties were predominantly within 1.5 standard deviations from the mean in-vitro data. When the material properties changed to Neo-Hookean, the outputs for kinematics and strain values were higher than the HGO case, and in most instances, they were outside the experimental range for ACL and MCL strains (by up to 11.35 SD) as well as some ITR angles (by up to 2.86 SD). Reported HGO material model with optimized coefficients produces a more realistic representation of the ligaments’ material properties, and will help improve the outcomes of FE models for more accurate predictions of knee behavior.
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.
文摘BACKGROUND Recently,the use of ligament advanced reinforcement system(LARS)artificial ligament,a new graft which has several unique advantages such as no donor-site morbidity,early recovery and no risk of disease transmission which has been a significant breakthrough for anatomical ligament reconstruction.Growing studies suggested that the special design of the LARS ligament with open fibers in its intra-articular part was believed to be more resistant to torsional fatigue and wearing.However,the safety and efficacy of LARS artificial ligament for ankle joint lateral collateral ankle ligament reconstruction has not been defined to date.AIM To evaluate the clinical results of all-arthroscopic anatomical reconstruction of ankle joint lateral collateral ligaments with the LARS artificial ligament for chronic ankle instability.METHODS Twenty-two patients with chronic lateral instability underwent anatomical reconstruction of the lateral collateral ligaments of ankle with LARS artificial ligament.The visual analogue score(VAS),American Orthopaedic Foot and Ankle Society score(AOFAS score)and Karlsson score were used to evaluate the clinical results before and after surgery.RESULTS A total of 22 patients(22 ankles)were followed up for a mean of 12 mo.All patients reported significant improvement compared to their preoperative status.The mean AOFAS score improved from 42.3±4.9 preoperatively to 90.4±6.7 postoperatively.The mean Karlsson score improved from 38.5±3.2 preoperatively to 90.1±7.8 postoperatively.The mean VAS score improved from 1.9±2.5 preoperatively to 0.8±1.7 postoperatively.CONCLUSION All-arthroscopic anatomical reconstruction of the lateral collateral ligaments with LARS artificial ligament achieved a satisfactory surgical outcome for chronic ankle instability.
基金supported by the National Natu-ral Science Foundation of China(Nos.32171340,81772343 and 81771990)the Key Medical Program of Science and Technol-ogy Development of Shanghai(No.20S31900400)the National Science Foundation of Shanghai(No.21ZR1447900).
文摘Design of artificial ligaments possessing both osteogenic activity and antibacterial effect that promotes ligament-bone healing and prevents bacterial infection in bone tunnels for anterior cruciate ligament(ACL)reconstruction remains a significant challenge.In this study,black tantalic oxide(BTO)submicro-particles with oxygen vacancies and structure defects were fabricated by using traditional white tan-talic oxide(WTO)through magnesium thermal reduction(MTR)method,and BTO was coated on polyetheretherketone(PEEK)fibers(PKF),which were woven into fabrics(PBT)as artificial ligaments.PBT with BTO coating exhibited excellent photothermal performance,which possessed not only antibac-terial effects in vitro but also anti-infective ability in vivo.PBT with optimized surface properties(e.g.,submicro-topography and hydrophilicity)not only significantly facilitated rat bone mesenchymal stem cells(BMSC)responses(e.g.,proliferation and osteogenic differentiation)in vitro but also stimulated new bone formation for ligament-bone healing in vivo.The presence of oxygen vacancies and structure de-fects in BTO did not change the surface properties and osteogenic activity of BPT while displaying an outstanding photothermal antibacterial effect.In summary,BPT with osteogenic activity and photother-mal antibacterial effect promoted bone regeneration and prevented bacterial infection,thereby promoting ligament-bone healing.Therefore,PBT would have tremendous potential as a novel artificial ligament for ACL reconstruction.
基金the National Natural Science Foundation of China (No. 30530230)
文摘To quantify mechanical effects of plantar fascia and ligaments on the arch structure,a 3D finite element model of the foot was created to simulate the balanced standing posture. Four cases after individual releases of plantar fascia,spring ligament,long and short plantar ligaments were simulated respectively to compare their consequences to the predictions of the intact structure. It was founded that the foot arch didn't collapse obviously after any individual release of these structures. As plantar fascia was released,tensions of plantar ligaments were largely increased. Long and short plantar ligaments performed mutual compensation functions.
文摘BACKGROUND Hypoplasia of bilateral cruciate ligaments is a rare congenital malformation.The diagnosis of such diseases and indications for the various treatment options require further analysis and discussion.CASE SUMMARY The patient is a 26-year-old Chinese woman who has been suffering from knee pain since the age of 8 years,2-3 episodes a year.Three years ago,due to the practice of advanced yoga poses,the frequency of left knee pain increased,requiring prompt medical treatment.Magnetic resonance imaging demonstrated an absence of both anterior and posterior cruciate ligaments of both knees with abnormal posterior tilting of the tibial plateau.Bilateral subluxation of the knee joint was also found,therefore tibial osteotomy was performed.The patient reported at the 24 mo follow-up that the frequency of pain and instability had been reduced and function restored.CONCLUSION Osteotomy may be an effective method to treat patients with congenital cruciate ligament deficiency with posterior tibial plateau tilting.The diagnosis of congenital cruciate ligament deficiency shall be based on the combination of patient’s medical history,clinical manifestations,and findings from imaging to avoid possible misdiagnosis.Based on the symptoms,frequency of attacks,and intent of the individual,appropriate treatment options shall be identified.
文摘A stress analysis is described for a nuclear steam generator tubesheet with a thin, or irregular ligament, associated with a mis-drilled hole using the rules of ASME （American Society of Mechanical Engineers） B ＆ PV Section Ⅲ and non-mandatory Appendix A, Article A-8000 for stresses in perforated flat plates. The analysis demonstrates the proper application of the NB-3200 rules for this special application, with discussion of the differences between an actual tube hole deviation and what is assumed in ASME Appendix A. This is a companion paper to ＂Technical Justification Supporting Operation with a Tube Installed in a Mis-Drilled Hole of a Steam Generator Tubesheet＂.
基金supported by the National Natural Science Foundation of China(Grant No.61902357)。
文摘The global rise in anterior cruciate ligament(ACL)injuries underscores the urgent need for high-performance artificial ligaments.However,long-term clinical use is still challenged by fabric structure disintegration,rupture,and pull-out failure.This study presents a straightforward strategy to enhance mechanical performance through knitted structural design,addressing the research gap between ligament architecture and pull-out resistance.A mathematical model was established to correlate structural parameters with the maximum pull-out force,guiding the optimization of the artificial ligament based on key mechanical properties.Furthermore,the interaction between the artificial ligament and the bone tunnel was analyzed using a mechanical ACL model.By varying the wales of underlapping per course from 2 to 5,the pull-out force of individual weft insertion yarns improved by up to 118.16%.The optimized ligament achieved a breaking strength close to 7000 N,approximately 40%higher than that of conventional designs,and exhibited an 18.85%reduction in fatigue deformation.In addition,it significantly enhanced the pull-out resistance of the bone tunnel.These findings provide valuable insights into improving the durability and structural reliability of other knitted biomedical implants.
