The purpose of this study was to compare the biomechanical stability obtained by using our technique featured an anatomical plate and compression bolts versus that of the conventional anatomic plate and cancellous scr...The purpose of this study was to compare the biomechanical stability obtained by using our technique featured an anatomical plate and compression bolts versus that of the conventional anatomic plate and cancellous screws in the fixation of intraarticular calcaneal fractures.Eighteen fresh frozen lower limbs of cadavers were used to create a reproductive Sanders type-Ⅲ calcaneal fracture model by using osteotomy.The calcaneus fractures were randomly selected to be fixed either using our anatomical plate and compression bolts or conventional anatomic plate and cancellous screws.Reduction of fracture was evaluated through X radiographs.Each calcaneus was successively loaded at a frequency of 1 Hz for 1000 cycles through the talus using an increasing axial force 20 N to 200 N and 20 N to 700 N,representing the partial weight bearing and full weight bearing,respectively,and then the specimens were loaded to failure.Data extracted from the mechanical testing machine were recorded and used to test for difference in the results with the Wilcoxon signed rank test.No significant difference was found between our fixation technique and conventional technique in displacement during 20-200 N cyclic loading(P=0.06),while the anatomical plate and compression bolts showed a great lower irreversible deformation during 20-700 N cyclic loading(P=0.008).The load achieved at loss of fixation of the constructs for the two groups had significant difference:anatomic plate and compression bolts at 3839.6±152.4 N and anatomic plate and cancellous screws at 3087.3±58.9 N(P=0.008).There was no significant difference between the ultimate displacements.Our technique featured anatomical plate and compression bolts for calcaneus fracture fixation was demonstrated to provide biomechanical stability as good as or better than the conventional anatomic plate and cancellous screws under the axial loading.The study supports the mechanical viability of using our plate and compression bolts for the fixation of calcaneal fracture.展开更多
A novel hydrophilic polyurethane (abbreviated as W-OH) was developed and applied as a sustainable sand-fixing material. This paper on the chemical sand fixation mechanism of W-OH discusses the adhesive force between t...A novel hydrophilic polyurethane (abbreviated as W-OH) was developed and applied as a sustainable sand-fixing material. This paper on the chemical sand fixation mechanism of W-OH discusses the adhesive force between the W-OH solid and sand particles. The solidification mechanism was investigated and the solidifying time was tested. And then the thickness and porosity of the W-OH sand-fixing layer were investigated. By scanning electron microscopy (SEM), the microstructure of the W-OH sand-fixing layer was examined. The hardness and compressive stress of the sand-fixing specimens were studied at W-OH different concentrations. Finally, the resistance to wind erosion of the W-OH sand-fixing layer was investigated by a wind tunnel test. The results demonstrated that the W-OH aqueous solution had an excellent affinity for water on the surface of the sand particles, and the adhesive force between the W-OH solid and sand was primarily hydrogen bonding, covalent bonds and physical absorption, such as Van Der Waals forces. W-OH is a prepolymer of hydrophilic polyurethane containing groups of -NCO that can quickly react with water and other groups containing active H. The W-OH aqueous solution solidified in the range of 2 min to 15 min. The solidifying time decreased with increasing temperature and concentration. Before solidifying it had a good permeability of sand and the formed sand-fixing layer had a thickness of 8 - 35 mm and a porosity of 25% - 8% at a spraying concentration of 2 - 10 L/m2. The hardness index of the sand-fixing layer was in the range of 21 mm to 28 mm and compressive stress was in the range from 0.21 MPa mm to 1.27 MPa, both of which increased linearly with W-OH concentration. Sand treated by over 3% W-OH concentrations showed excellent resistance to wind/sand erosion of more than 25 m/s.展开更多
AIM: To develop new fixation techniques for the treatment of periprosthetic fractures using intraprosthetic screw fixation with inserted threaded liners. METHODS: A Vancouver B1 periprosthetic fracture was simulated i...AIM: To develop new fixation techniques for the treatment of periprosthetic fractures using intraprosthetic screw fixation with inserted threaded liners. METHODS: A Vancouver B1 periprosthetic fracture was simulated in femur prosthesis constructs using sawbones and cemented regular straight hip stems. Fixation was then performed with either unicortical locked-screw plating using the less invasive stabilization system-plate or with intraprosthetic screw fixation using inserted liners. Two experimental groups were formed using either prostheses made of titanium alloy or prostheses made of cobalt chrome alloy. Fixation stability was compared in an axial load-to-failure model. Drilling was performed using a specially invented prosthesis drill with constantly applied internal cooling.RESULTS: The intraprosthetic fixation model with titanium prostheses was superior to the unicortical lockedscrew fixation in all tested devices. The intraprosthetic fixation model required 10 456 N ± 1892 N for failure and the unicortical locked-screw plating required 7649 N ± 653 N(P < 0.05). There was no significant difference between the second experimental group and the control group.CONCLUSION: Intraprosthetic screw anchorage with special threaded liners enhances the primary stability in treating periprosthetic fractures by internal fixation.展开更多
Background Absorbable cranial flap fixation products,represented by Aesculap^(®)CranioFix absorbable clamp,are widely used in neurosurgery.However,the product has some shortcomings,as it is not entirely biodegrad...Background Absorbable cranial flap fixation products,represented by Aesculap^(®)CranioFix absorbable clamp,are widely used in neurosurgery.However,the product has some shortcomings,as it is not entirely biodegradable,the lower disc’s angle cannot be adjusted,and there is a failure to readjust after fixation.To address these issues,MedArt Technology Co.,Ltd.from China has come up with a high-purity PLLA combined with an innovative structural design to develop a novel cranial flap fixation system that is more convenient to operate,has a better resetting effect,and can be fully absorbed.This study aims to verify its safety and effectiveness through in vitro experiments and clinical trials.Methods In this study,the absorbable cranial flap fixation system of MedArt was used as the experimental group,and the CranioFix absorbable clamp constituted the control group.The material properties and the changing trend of mechanical properties of the two groups were compared by accelerated degradation experiments in vitro.A multicenter,randomized,parallel,positive-controlled,non-inferiority clinical study was conducted with a 48-week follow-up.The shortening degree of the bone flap gap,qualified rate of bone flap displacement,changing trend of implant volume,and occurrence of postoperative adverse events were compared between the two groups.Results The results of the in vitro accelerated degradation showed that in terms of the decrease in intrinsic viscosity,the control and experimental groups took 7 days and 14 days,respectively,to reach the test endpoint.For mechanical properties,the control group and experimental groups lost clinical safety fixation significance on the 3rd and 4th day after the degradation began,respectively.Regarding the release of degradation products,the control group showed a burst of lactic acid release during the first 3-7 days,while the experimental group released lactic acid slowly and constantly.In the clinical study,90 patients were randomly enrolled,87 of whom completed the operation,with an average age of 50.The 3D reconstruction of CT images showed that the bone flap gaps in both groups were less than 2 mm after surgery.The qualified rate of bone flap displacement in the experimental group was 100%after surgery.In contrast,in the control group,there was one unqualified case at 1 week after surgery and two unqualified cases at 6 weeks,12 weeks,24 weeks,and 48 weeks.The residual volume of the implant in the experimental group was closer to 50%(about 48.8%)48 weeks after surgery,than in the control group(about 43.9%)12 weeks after surgery.Regarding safety,only one possible device-related adverse event occurred in the control group,with an incidence rate of 2.22%,manifested as poor healing at the incision site.Conclusions The study has verified that the experimental group had better stability,longer biodegradation time,and better mechanical properties than the control group.Moreover,the experimental group could significantly narrow the cranial flap gap,reduce the flap displacement,and promote skull healing after craniotomy.It shows a fairly reliable fixation effect and safety.展开更多
目的对单纯肱骨大结节骨折的3种不同内固定方式(螺钉、张力带、肱骨大结节锁定钢板)进行生物力学测试,比较其稳定性,为临床肱骨大结节骨折内固定物的选择提供生物力学依据。方法取18具保留肩袖肌的新鲜冰冻成人肱骨尸体标本,建立肱骨大...目的对单纯肱骨大结节骨折的3种不同内固定方式(螺钉、张力带、肱骨大结节锁定钢板)进行生物力学测试,比较其稳定性,为临床肱骨大结节骨折内固定物的选择提供生物力学依据。方法取18具保留肩袖肌的新鲜冰冻成人肱骨尸体标本,建立肱骨大结节骨折模型后,随机编号分为3组,分别采用螺钉、张力带及肱骨大结节锁定钢板技术固定大结节骨折块,牵拉冈上肌,测试力-位移曲线,记录2组参数:大结节移位5 mm时力的大小(load to 5 mm yield point,LtYP)及失效负荷(load to failure,LtF)。结果 3组标本(螺钉组、张力带组、肱骨大结节锁定钢板组)在大结节移位5 mm时力的大小分别为(377±86)、(499±90)、(793±52)N,3组标本间LtYP差异有统计学意义(P<0.01);两两比较,锁定钢板组LtYP远大于螺钉组(本研究中仅3例在内固定失效前位移达到5 mm),差异有统计学意义(P<0.01),锁定钢板组LtYP相比张力带组差异有统计学意义(P<0.01),张力带组LtYP相对螺钉组表现出明显的统计学意义(P<0.01)。3组标本失效负荷分别为(744±112)、(908±93)、(979±143)N,3组标本间LtF差异有统计学意义(P<0.01);锁定钢板组LtF相对螺钉组具有明显的统计学意义(P<0.01),张力带组LtF相对螺钉组有统计学意义(P<0.01),但锁定钢板组LtF与张力带组之间无明显统计学差异(P>0.05)。结论肱骨大结节锁定钢板组相对螺钉组及张力带组表现出明显的生物力学优势,锁定钢板将为临床治疗单纯肱骨大结节骨折提供新的、更好的选择。展开更多
目的探讨动力髋螺钉(DHS)、股骨近端防旋髓内钉(PFNA)、Inter Tan 3种内固定材料固定股骨粗隆下骨折生物力学性能,为临床选择有效内固定方式提供科学依据。方法采购人工股骨标本18根,按照Seinsheimer分型Ⅲa型予以截骨制作成粗隆下骨折...目的探讨动力髋螺钉(DHS)、股骨近端防旋髓内钉(PFNA)、Inter Tan 3种内固定材料固定股骨粗隆下骨折生物力学性能,为临床选择有效内固定方式提供科学依据。方法采购人工股骨标本18根,按照Seinsheimer分型Ⅲa型予以截骨制作成粗隆下骨折模型,分别用3种内固定材料固定,进行股骨的强度、刚度、稳定性、承载能力测式等生物力学实验,分析比较3种内固定方式固定股骨粗隆下骨折的生物力学性能。结果实验力学结果表明:Inter Tan髓内钉固定强度为(1.84±0.15)MPa,DHS为(1.39±0.11)MPa,PFNA为(1.36±0.12)MPa内固定的强度,Inter Tan组内固定强度大于DHS组和PFNA组,差异有统计学意义(P<0.05);Inter Tan组刚度EF为(945.35±82.01)N/mm,DHS为(638.54±78.21)N/mm,PFNA为(755.33±86.32)N/mm,Inter Tan组刚度大于DHS组和PFNA组,差异有统计学意义(P<0.05);Inter Tan组的抗剪、抗扭的稳定性、承载能力均明显优于DHS、PFNA组,差异有统计学意义(P<0.05);其动态力学性能疲劳寿命也相应比DHS、PFNA组优越。结论 Inter Tan及PFNA均是固定Ⅲa型股骨粗隆下骨折的理想方法,其中Inter Tan整体生物力学性能优于PFNA髓内钉固定,而DHS不适用于此型股骨粗隆下骨折。展开更多
文摘The purpose of this study was to compare the biomechanical stability obtained by using our technique featured an anatomical plate and compression bolts versus that of the conventional anatomic plate and cancellous screws in the fixation of intraarticular calcaneal fractures.Eighteen fresh frozen lower limbs of cadavers were used to create a reproductive Sanders type-Ⅲ calcaneal fracture model by using osteotomy.The calcaneus fractures were randomly selected to be fixed either using our anatomical plate and compression bolts or conventional anatomic plate and cancellous screws.Reduction of fracture was evaluated through X radiographs.Each calcaneus was successively loaded at a frequency of 1 Hz for 1000 cycles through the talus using an increasing axial force 20 N to 200 N and 20 N to 700 N,representing the partial weight bearing and full weight bearing,respectively,and then the specimens were loaded to failure.Data extracted from the mechanical testing machine were recorded and used to test for difference in the results with the Wilcoxon signed rank test.No significant difference was found between our fixation technique and conventional technique in displacement during 20-200 N cyclic loading(P=0.06),while the anatomical plate and compression bolts showed a great lower irreversible deformation during 20-700 N cyclic loading(P=0.008).The load achieved at loss of fixation of the constructs for the two groups had significant difference:anatomic plate and compression bolts at 3839.6±152.4 N and anatomic plate and cancellous screws at 3087.3±58.9 N(P=0.008).There was no significant difference between the ultimate displacements.Our technique featured anatomical plate and compression bolts for calcaneus fracture fixation was demonstrated to provide biomechanical stability as good as or better than the conventional anatomic plate and cancellous screws under the axial loading.The study supports the mechanical viability of using our plate and compression bolts for the fixation of calcaneal fracture.
文摘A novel hydrophilic polyurethane (abbreviated as W-OH) was developed and applied as a sustainable sand-fixing material. This paper on the chemical sand fixation mechanism of W-OH discusses the adhesive force between the W-OH solid and sand particles. The solidification mechanism was investigated and the solidifying time was tested. And then the thickness and porosity of the W-OH sand-fixing layer were investigated. By scanning electron microscopy (SEM), the microstructure of the W-OH sand-fixing layer was examined. The hardness and compressive stress of the sand-fixing specimens were studied at W-OH different concentrations. Finally, the resistance to wind erosion of the W-OH sand-fixing layer was investigated by a wind tunnel test. The results demonstrated that the W-OH aqueous solution had an excellent affinity for water on the surface of the sand particles, and the adhesive force between the W-OH solid and sand was primarily hydrogen bonding, covalent bonds and physical absorption, such as Van Der Waals forces. W-OH is a prepolymer of hydrophilic polyurethane containing groups of -NCO that can quickly react with water and other groups containing active H. The W-OH aqueous solution solidified in the range of 2 min to 15 min. The solidifying time decreased with increasing temperature and concentration. Before solidifying it had a good permeability of sand and the formed sand-fixing layer had a thickness of 8 - 35 mm and a porosity of 25% - 8% at a spraying concentration of 2 - 10 L/m2. The hardness index of the sand-fixing layer was in the range of 21 mm to 28 mm and compressive stress was in the range from 0.21 MPa mm to 1.27 MPa, both of which increased linearly with W-OH concentration. Sand treated by over 3% W-OH concentrations showed excellent resistance to wind/sand erosion of more than 25 m/s.
文摘AIM: To develop new fixation techniques for the treatment of periprosthetic fractures using intraprosthetic screw fixation with inserted threaded liners. METHODS: A Vancouver B1 periprosthetic fracture was simulated in femur prosthesis constructs using sawbones and cemented regular straight hip stems. Fixation was then performed with either unicortical locked-screw plating using the less invasive stabilization system-plate or with intraprosthetic screw fixation using inserted liners. Two experimental groups were formed using either prostheses made of titanium alloy or prostheses made of cobalt chrome alloy. Fixation stability was compared in an axial load-to-failure model. Drilling was performed using a specially invented prosthesis drill with constantly applied internal cooling.RESULTS: The intraprosthetic fixation model with titanium prostheses was superior to the unicortical lockedscrew fixation in all tested devices. The intraprosthetic fixation model required 10 456 N ± 1892 N for failure and the unicortical locked-screw plating required 7649 N ± 653 N(P < 0.05). There was no significant difference between the second experimental group and the control group.CONCLUSION: Intraprosthetic screw anchorage with special threaded liners enhances the primary stability in treating periprosthetic fractures by internal fixation.
基金funded by MedArt Technology Co.,Ltd.,located in Chengdu,China.The company supplied cranial flap fixation products utilized in the study and provided financial support for the research.
文摘Background Absorbable cranial flap fixation products,represented by Aesculap^(®)CranioFix absorbable clamp,are widely used in neurosurgery.However,the product has some shortcomings,as it is not entirely biodegradable,the lower disc’s angle cannot be adjusted,and there is a failure to readjust after fixation.To address these issues,MedArt Technology Co.,Ltd.from China has come up with a high-purity PLLA combined with an innovative structural design to develop a novel cranial flap fixation system that is more convenient to operate,has a better resetting effect,and can be fully absorbed.This study aims to verify its safety and effectiveness through in vitro experiments and clinical trials.Methods In this study,the absorbable cranial flap fixation system of MedArt was used as the experimental group,and the CranioFix absorbable clamp constituted the control group.The material properties and the changing trend of mechanical properties of the two groups were compared by accelerated degradation experiments in vitro.A multicenter,randomized,parallel,positive-controlled,non-inferiority clinical study was conducted with a 48-week follow-up.The shortening degree of the bone flap gap,qualified rate of bone flap displacement,changing trend of implant volume,and occurrence of postoperative adverse events were compared between the two groups.Results The results of the in vitro accelerated degradation showed that in terms of the decrease in intrinsic viscosity,the control and experimental groups took 7 days and 14 days,respectively,to reach the test endpoint.For mechanical properties,the control group and experimental groups lost clinical safety fixation significance on the 3rd and 4th day after the degradation began,respectively.Regarding the release of degradation products,the control group showed a burst of lactic acid release during the first 3-7 days,while the experimental group released lactic acid slowly and constantly.In the clinical study,90 patients were randomly enrolled,87 of whom completed the operation,with an average age of 50.The 3D reconstruction of CT images showed that the bone flap gaps in both groups were less than 2 mm after surgery.The qualified rate of bone flap displacement in the experimental group was 100%after surgery.In contrast,in the control group,there was one unqualified case at 1 week after surgery and two unqualified cases at 6 weeks,12 weeks,24 weeks,and 48 weeks.The residual volume of the implant in the experimental group was closer to 50%(about 48.8%)48 weeks after surgery,than in the control group(about 43.9%)12 weeks after surgery.Regarding safety,only one possible device-related adverse event occurred in the control group,with an incidence rate of 2.22%,manifested as poor healing at the incision site.Conclusions The study has verified that the experimental group had better stability,longer biodegradation time,and better mechanical properties than the control group.Moreover,the experimental group could significantly narrow the cranial flap gap,reduce the flap displacement,and promote skull healing after craniotomy.It shows a fairly reliable fixation effect and safety.
文摘目的对单纯肱骨大结节骨折的3种不同内固定方式(螺钉、张力带、肱骨大结节锁定钢板)进行生物力学测试,比较其稳定性,为临床肱骨大结节骨折内固定物的选择提供生物力学依据。方法取18具保留肩袖肌的新鲜冰冻成人肱骨尸体标本,建立肱骨大结节骨折模型后,随机编号分为3组,分别采用螺钉、张力带及肱骨大结节锁定钢板技术固定大结节骨折块,牵拉冈上肌,测试力-位移曲线,记录2组参数:大结节移位5 mm时力的大小(load to 5 mm yield point,LtYP)及失效负荷(load to failure,LtF)。结果 3组标本(螺钉组、张力带组、肱骨大结节锁定钢板组)在大结节移位5 mm时力的大小分别为(377±86)、(499±90)、(793±52)N,3组标本间LtYP差异有统计学意义(P<0.01);两两比较,锁定钢板组LtYP远大于螺钉组(本研究中仅3例在内固定失效前位移达到5 mm),差异有统计学意义(P<0.01),锁定钢板组LtYP相比张力带组差异有统计学意义(P<0.01),张力带组LtYP相对螺钉组表现出明显的统计学意义(P<0.01)。3组标本失效负荷分别为(744±112)、(908±93)、(979±143)N,3组标本间LtF差异有统计学意义(P<0.01);锁定钢板组LtF相对螺钉组具有明显的统计学意义(P<0.01),张力带组LtF相对螺钉组有统计学意义(P<0.01),但锁定钢板组LtF与张力带组之间无明显统计学差异(P>0.05)。结论肱骨大结节锁定钢板组相对螺钉组及张力带组表现出明显的生物力学优势,锁定钢板将为临床治疗单纯肱骨大结节骨折提供新的、更好的选择。
