The influences and mechanisms of the physiology,rupture and reconstruction of the anterior cruciate ligament(ACL)on kinematics and clinical outcomes have been investigated in many biomechanical and clinical studies ov...The influences and mechanisms of the physiology,rupture and reconstruction of the anterior cruciate ligament(ACL)on kinematics and clinical outcomes have been investigated in many biomechanical and clinical studies over the last several decades.The knee is a complex joint with shifting contact points,pressures and axes that are affected when a ligament is injured.The ACL,as one of the intra-articular ligaments,has a strong influence on the resulting kinematics.Often,other meniscal or ligamentous injuries accompany ACL ruptures and further deteriorate the resulting kinematics and clinical outcomes.Knowing the surgical options,anatomic relations and current evidence to restore ACL function and considering the influence of concomitant injuries on resulting kinematics to restore full function can together help to achieve an optimal outcome.展开更多
Total temporomandibular joint(TMJ)replacement is recommended only when there is irreversible damage to the joint and no conservative treatment can provide functional improvements.Several stock and custom-made TMJ impl...Total temporomandibular joint(TMJ)replacement is recommended only when there is irreversible damage to the joint and no conservative treatment can provide functional improvements.Several stock and custom-made TMJ implants have been made available;however,retrospective and comparative studies were unable to find significant differences between the two types of solutions.The introduction of additive manufacturing(AM)techniques in medical practice allows for a greater freedom of design and a higher degree of device customisation.The combination of AM with structural optimisation may streamline development and provide the key for fabricating biomechanic ally enhanced TMJ implants.In this study,structural optimis ation techniques were applied to develop and numerically validate a patient-specific TMJ implant.The biomechanical behaviour of each intermediate TMJ design was assessed under four different nominal and maximum biting tasks using finite element analyses.In addition,a new set of metrics were proposed to compare each design regarding biomechanical performance and implant safety.The results suggest that 55-82%of the natural/intact strain patterns can be recovered with the finally selected TMJ implant.This represents an increase of 15%in biomechanical performance for incisor biting,15%for right molar biting,17%for left molar biting and a decrease of 2%for left group biting compared with the initial design.The results also suggest that load transfer at the proximal ramus reduces the implant’s impact on the mandible’s strain patterns.Finally,structural optimisation allows for a volume reduction of up to 44%with a minimum loss of implant safety and biomechanical performance.展开更多
目的:使用三维运动分析系统观察不同严重程度的膝骨关节炎(Knee Osteoarthritis,KOA)恐动症(低KOA恐动症、高KOA恐动症)患者与年龄匹配的无KOA症状人群在登梯过程中姿势稳定性和下肢关节角度的差异。方法:运用三维运动分析系统检测低KO...目的:使用三维运动分析系统观察不同严重程度的膝骨关节炎(Knee Osteoarthritis,KOA)恐动症(低KOA恐动症、高KOA恐动症)患者与年龄匹配的无KOA症状人群在登梯过程中姿势稳定性和下肢关节角度的差异。方法:运用三维运动分析系统检测低KOA恐动症患者、高KOA恐动症患者和无KOA症状人群共78例受试者在登梯过程中的姿势稳定性(Mar‐gin of Stability,MoS)和关节角度等生物力学因素的差异。结果:低、高KOA恐动症患者在登梯过程中在矢状面和冠状面MoS较差,上梯时髋屈曲和内收最大角度及膝屈伸活动范围均增加;低KOA恐动症患者踝背屈和膝屈曲最大角度均减小;低KOA恐动症患者膝屈曲最大角度低于高KOA恐动症患者。下梯时,低、高KOA恐动症患者髋屈曲最大角度增加,低KOA恐动症患者踝内外翻活动范围增加,高KOA恐动症患者髋内收最大角度增加。结论:低、高KOA恐动症患者在登梯时矢状面和冠状面稳定性较差,但未发现恐动症对KOA患者的显著影响。展开更多
背景:发育性髋关节发育不良常易导致患儿肢体畸形,其诊疗的相关研究已逐渐明确;近来有限元法因其优势在发育性髋关节发育不良的相关研究中受到学者重视。目的:通过文献检索综述有限元法在儿童发育性髋关节发育不良及治疗中的研究进展,...背景:发育性髋关节发育不良常易导致患儿肢体畸形,其诊疗的相关研究已逐渐明确;近来有限元法因其优势在发育性髋关节发育不良的相关研究中受到学者重视。目的:通过文献检索综述有限元法在儿童发育性髋关节发育不良及治疗中的研究进展,分析总结其优势与不足,并探讨未来进一步研究的方向及应用前景。方法:应用计算机在Pub Med、SCI、CBM和中国知网数据库中检索2014年1月至2023年11月发表的相关文献,以“developmental dysplasia(dislocation) of the hip,dysplasia of the hip,finite element analysis(method),pavlik harness,fixation in herringbone position,biomechanics,pelvic osteotomies,pemberton,salter,dega,periacetabular osteotomy,children”为英文检索词,以“发育性髋关节发育不良,发育性髋关节脱位,髋关节发育不良,儿童,有限元,Pavlik吊带,人字型固定,生物力学,骨盆截骨术,髋臼周围截骨术”为中文检索词,同时纳入少量远期文献,通过筛选最终纳入62篇文献进行分析。结果与结论:(1)儿童发育性髋关节发育不良髋关节力学环境异常,髋臼内部压力不均匀、应力增大并集中,关节接触面积减小,股骨颈局部应力集中;(2)在Pavlik吊带及人字型固定位患髋力学环境改善,集中的高应力区域消失,关节接触面积增加,但外展角度过大会导致髋臼及股骨头外侧应力增加;(3)骨盆截骨术治疗后髋关节及骶髂关节应力环境得到改善,3种截骨术没有单一的铰链,其应力负载部位因患儿年龄而存在差异;(4)髋臼周围截骨术治疗后关节接触压力接近正常,而非球形股骨头者恢复困难;(5)术后X射线片表现不能说明关节接触力学达到最佳;(6)提示利用有限元法可以获得体内无法测量的信息,其在虚拟环境中操作不受时间和伦理的限制;能直观地看到正常与发育性髋关节发育不良患者髋关节应力变化的区域,从力学角度说明治疗的有效性,为需要截骨手术治疗的患者建立特定的有限元模型、量身定做手术计划;发育性髋关节发育不良的有限元建模及儿童髋关节材料特性参数尚无规范、统一的标准,由于有限元固有的局限性,目前还不能分析同时包含骨骼、软骨、韧带、肌肉等元素的模型;有限元分析操作难度较大,虽有优势但不具普适性,且目前的研究样本量较少,还需进一步扩大及验证。展开更多
基金Supported by A Research fellowship from the faculty of Medicine,Westphalian Wilhelms University Muenster to Domnick C
文摘The influences and mechanisms of the physiology,rupture and reconstruction of the anterior cruciate ligament(ACL)on kinematics and clinical outcomes have been investigated in many biomechanical and clinical studies over the last several decades.The knee is a complex joint with shifting contact points,pressures and axes that are affected when a ligament is injured.The ACL,as one of the intra-articular ligaments,has a strong influence on the resulting kinematics.Often,other meniscal or ligamentous injuries accompany ACL ruptures and further deteriorate the resulting kinematics and clinical outcomes.Knowing the surgical options,anatomic relations and current evidence to restore ACL function and considering the influence of concomitant injuries on resulting kinematics to restore full function can together help to achieve an optimal outcome.
基金funding from the Interreg 2 Seas program 2014-2020 co-funded by the European Regional Development Fund under subsidy contract no.2S04-014。
文摘Total temporomandibular joint(TMJ)replacement is recommended only when there is irreversible damage to the joint and no conservative treatment can provide functional improvements.Several stock and custom-made TMJ implants have been made available;however,retrospective and comparative studies were unable to find significant differences between the two types of solutions.The introduction of additive manufacturing(AM)techniques in medical practice allows for a greater freedom of design and a higher degree of device customisation.The combination of AM with structural optimisation may streamline development and provide the key for fabricating biomechanic ally enhanced TMJ implants.In this study,structural optimis ation techniques were applied to develop and numerically validate a patient-specific TMJ implant.The biomechanical behaviour of each intermediate TMJ design was assessed under four different nominal and maximum biting tasks using finite element analyses.In addition,a new set of metrics were proposed to compare each design regarding biomechanical performance and implant safety.The results suggest that 55-82%of the natural/intact strain patterns can be recovered with the finally selected TMJ implant.This represents an increase of 15%in biomechanical performance for incisor biting,15%for right molar biting,17%for left molar biting and a decrease of 2%for left group biting compared with the initial design.The results also suggest that load transfer at the proximal ramus reduces the implant’s impact on the mandible’s strain patterns.Finally,structural optimisation allows for a volume reduction of up to 44%with a minimum loss of implant safety and biomechanical performance.
文摘目的:使用三维运动分析系统观察不同严重程度的膝骨关节炎(Knee Osteoarthritis,KOA)恐动症(低KOA恐动症、高KOA恐动症)患者与年龄匹配的无KOA症状人群在登梯过程中姿势稳定性和下肢关节角度的差异。方法:运用三维运动分析系统检测低KOA恐动症患者、高KOA恐动症患者和无KOA症状人群共78例受试者在登梯过程中的姿势稳定性(Mar‐gin of Stability,MoS)和关节角度等生物力学因素的差异。结果:低、高KOA恐动症患者在登梯过程中在矢状面和冠状面MoS较差,上梯时髋屈曲和内收最大角度及膝屈伸活动范围均增加;低KOA恐动症患者踝背屈和膝屈曲最大角度均减小;低KOA恐动症患者膝屈曲最大角度低于高KOA恐动症患者。下梯时,低、高KOA恐动症患者髋屈曲最大角度增加,低KOA恐动症患者踝内外翻活动范围增加,高KOA恐动症患者髋内收最大角度增加。结论:低、高KOA恐动症患者在登梯时矢状面和冠状面稳定性较差,但未发现恐动症对KOA患者的显著影响。
文摘背景:发育性髋关节发育不良常易导致患儿肢体畸形,其诊疗的相关研究已逐渐明确;近来有限元法因其优势在发育性髋关节发育不良的相关研究中受到学者重视。目的:通过文献检索综述有限元法在儿童发育性髋关节发育不良及治疗中的研究进展,分析总结其优势与不足,并探讨未来进一步研究的方向及应用前景。方法:应用计算机在Pub Med、SCI、CBM和中国知网数据库中检索2014年1月至2023年11月发表的相关文献,以“developmental dysplasia(dislocation) of the hip,dysplasia of the hip,finite element analysis(method),pavlik harness,fixation in herringbone position,biomechanics,pelvic osteotomies,pemberton,salter,dega,periacetabular osteotomy,children”为英文检索词,以“发育性髋关节发育不良,发育性髋关节脱位,髋关节发育不良,儿童,有限元,Pavlik吊带,人字型固定,生物力学,骨盆截骨术,髋臼周围截骨术”为中文检索词,同时纳入少量远期文献,通过筛选最终纳入62篇文献进行分析。结果与结论:(1)儿童发育性髋关节发育不良髋关节力学环境异常,髋臼内部压力不均匀、应力增大并集中,关节接触面积减小,股骨颈局部应力集中;(2)在Pavlik吊带及人字型固定位患髋力学环境改善,集中的高应力区域消失,关节接触面积增加,但外展角度过大会导致髋臼及股骨头外侧应力增加;(3)骨盆截骨术治疗后髋关节及骶髂关节应力环境得到改善,3种截骨术没有单一的铰链,其应力负载部位因患儿年龄而存在差异;(4)髋臼周围截骨术治疗后关节接触压力接近正常,而非球形股骨头者恢复困难;(5)术后X射线片表现不能说明关节接触力学达到最佳;(6)提示利用有限元法可以获得体内无法测量的信息,其在虚拟环境中操作不受时间和伦理的限制;能直观地看到正常与发育性髋关节发育不良患者髋关节应力变化的区域,从力学角度说明治疗的有效性,为需要截骨手术治疗的患者建立特定的有限元模型、量身定做手术计划;发育性髋关节发育不良的有限元建模及儿童髋关节材料特性参数尚无规范、统一的标准,由于有限元固有的局限性,目前还不能分析同时包含骨骼、软骨、韧带、肌肉等元素的模型;有限元分析操作难度较大,虽有优势但不具普适性,且目前的研究样本量较少,还需进一步扩大及验证。