This work focuses on the influence of elastic modulus on biomechanical properties of lumbar interbody fusion cages by selecting two titanium alloys with different elastic modulus. They were made by a new β type alloy...This work focuses on the influence of elastic modulus on biomechanical properties of lumbar interbody fusion cages by selecting two titanium alloys with different elastic modulus. They were made by a new β type alloy with chemical composition of Ti-24Nb-4Zr-7.6Sn having low Young＇s modulus -50 GPa and by a conventional biomedical alloy Ti-6Al-4V having Young＇s modulus -110 GPa. The results showed that the designed cages with low modulus （LMC） and high modulus （HMC） can keep identical compression load -9.8 kN and endure fatigue cycles higher than 5× 10^6 without functional or mechanical failure under 2.0 kN axial compression. The anti-subsidence ability of both group cages were examined by axial compression of thoracic spine specimens （T9-T10） dissected freshly from the calf with averaged age of 6 months. The results showed that the LMC has better anti-subsidence ability than the HMC （p〈0.05）. The above results suggest that the cage with low elastic modulus has great potential for clinical applications.展开更多
Few biomechanical data exist regarding whether the polyetheretherketone (PEEK) spacer or titanium spacer is better for posterior lumbar interbody fusion (PLIF). This study evaluated the biomechanical influence that th...Few biomechanical data exist regarding whether the polyetheretherketone (PEEK) spacer or titanium spacer is better for posterior lumbar interbody fusion (PLIF). This study evaluated the biomechanical influence that these types of spacers with different levels of hardness exert on the vertebra by using finite element analysis including bone strength distribution. To evaluate the risk of spacer subsidence for PLIF, we built a finite element model of the lumbar spine using computed tomography data of osteoporosis patients. Then, we simulated PLIF in L3/4 and built models with the hardness of the interbody spacer set as PEEK and titanium. Bones around the spacer were subjected to different load conditions. Then, fracture elements and some stress states of the two modalities were compared. In both models of PLIF simulation, fracture elements and stress were concentrated in the bones around the spacer. Fracture elements and stress values of the model simulating the PEEK spacer were significantly smaller compared to those of the titanium simulation model. For PLIF of osteoporotic vertebrae, this suggested that the PEEK spacer is in a mechanical environment less susceptible to subsidence caused by microfractures of bone tissue and bone remodeling-related fusion aspects. Therefore, PEEK spacers are bio-mechanically more useful.展开更多
目的探讨终板体积骨密度(endplate volumetric bone mineral density,EP-vBMD)对侧方入路腰椎融合(lateral lumbar interbody fusion,LLIF)术后Cage沉降的影响。方法选择2018年1月~2020年12月在本院接受LLIF手术治疗的151例患者进行回...目的探讨终板体积骨密度(endplate volumetric bone mineral density,EP-vBMD)对侧方入路腰椎融合(lateral lumbar interbody fusion,LLIF)术后Cage沉降的影响。方法选择2018年1月~2020年12月在本院接受LLIF手术治疗的151例患者进行回顾性分析,收集患者EP-vBMD、椎体体积骨密度(vertebral body volumetric bone mineral density,VB-vBMD)、年龄、性别、体质量指数(body mass index,BMI)、医学共病(糖尿病等)、吸烟、美国麻醉医师协会(american society of anesthesiologists,ASA)评分、查尔森共病指数(charlson comorbidity index,CCI)、手术节段、手术椎体和是否使用后路螺钉固定等资料。根据术后1年患者是否发生Cage沉降,将患者分为Cage沉降组和非沉降组,比较两组患者临床资料差异,将单因素分析P<0.2的变量进一步采用多因素Logsitic回归分析,观察EP-vBMD对终板沉陷的影响。结果Cage沉降患者的VB-vBMD和EP-vBMD水平均低于非Cage沉降患者,差异均有统计学意义(P<0.05)。Cage沉降组患者年龄高于非Cage沉降组患者,差异有统计学意义(P<0.05);Cage沉降组和非Cage沉降组患者性别、吸烟、糖尿病、后路螺钉固定等资料差异均有统计学意义(P<0.05)。多因素Logistic回归分析显示,EP-vBMD和应用后路螺钉固定均是Cage沉降的保护性因素(P<0.05)。结论低EP-vBMD是LLIF术后Cage沉降的风险因素,对患者进行LLIF时,应考虑术前EP-vBMD的测量。展开更多
文摘This work focuses on the influence of elastic modulus on biomechanical properties of lumbar interbody fusion cages by selecting two titanium alloys with different elastic modulus. They were made by a new β type alloy with chemical composition of Ti-24Nb-4Zr-7.6Sn having low Young＇s modulus -50 GPa and by a conventional biomedical alloy Ti-6Al-4V having Young＇s modulus -110 GPa. The results showed that the designed cages with low modulus （LMC） and high modulus （HMC） can keep identical compression load -9.8 kN and endure fatigue cycles higher than 5× 10^6 without functional or mechanical failure under 2.0 kN axial compression. The anti-subsidence ability of both group cages were examined by axial compression of thoracic spine specimens （T9-T10） dissected freshly from the calf with averaged age of 6 months. The results showed that the LMC has better anti-subsidence ability than the HMC （p〈0.05）. The above results suggest that the cage with low elastic modulus has great potential for clinical applications.
文摘Few biomechanical data exist regarding whether the polyetheretherketone (PEEK) spacer or titanium spacer is better for posterior lumbar interbody fusion (PLIF). This study evaluated the biomechanical influence that these types of spacers with different levels of hardness exert on the vertebra by using finite element analysis including bone strength distribution. To evaluate the risk of spacer subsidence for PLIF, we built a finite element model of the lumbar spine using computed tomography data of osteoporosis patients. Then, we simulated PLIF in L3/4 and built models with the hardness of the interbody spacer set as PEEK and titanium. Bones around the spacer were subjected to different load conditions. Then, fracture elements and some stress states of the two modalities were compared. In both models of PLIF simulation, fracture elements and stress were concentrated in the bones around the spacer. Fracture elements and stress values of the model simulating the PEEK spacer were significantly smaller compared to those of the titanium simulation model. For PLIF of osteoporotic vertebrae, this suggested that the PEEK spacer is in a mechanical environment less susceptible to subsidence caused by microfractures of bone tissue and bone remodeling-related fusion aspects. Therefore, PEEK spacers are bio-mechanically more useful.
文摘目的探讨终板体积骨密度(endplate volumetric bone mineral density,EP-vBMD)对侧方入路腰椎融合(lateral lumbar interbody fusion,LLIF)术后Cage沉降的影响。方法选择2018年1月~2020年12月在本院接受LLIF手术治疗的151例患者进行回顾性分析,收集患者EP-vBMD、椎体体积骨密度(vertebral body volumetric bone mineral density,VB-vBMD)、年龄、性别、体质量指数(body mass index,BMI)、医学共病(糖尿病等)、吸烟、美国麻醉医师协会(american society of anesthesiologists,ASA)评分、查尔森共病指数(charlson comorbidity index,CCI)、手术节段、手术椎体和是否使用后路螺钉固定等资料。根据术后1年患者是否发生Cage沉降,将患者分为Cage沉降组和非沉降组,比较两组患者临床资料差异,将单因素分析P<0.2的变量进一步采用多因素Logsitic回归分析,观察EP-vBMD对终板沉陷的影响。结果Cage沉降患者的VB-vBMD和EP-vBMD水平均低于非Cage沉降患者,差异均有统计学意义(P<0.05)。Cage沉降组患者年龄高于非Cage沉降组患者,差异有统计学意义(P<0.05);Cage沉降组和非Cage沉降组患者性别、吸烟、糖尿病、后路螺钉固定等资料差异均有统计学意义(P<0.05)。多因素Logistic回归分析显示,EP-vBMD和应用后路螺钉固定均是Cage沉降的保护性因素(P<0.05)。结论低EP-vBMD是LLIF术后Cage沉降的风险因素,对患者进行LLIF时,应考虑术前EP-vBMD的测量。
