Background: Infants with congenital muscular torticollis are born with an asymmetric range of motion and a muscular imbalance in the cervical spine, as a result of a shortening or excessive contraction of the sternocl...Background: Infants with congenital muscular torticollis are born with an asymmetric range of motion and a muscular imbalance in the cervical spine, as a result of a shortening or excessive contraction of the sternocleidomastoid muscle. Purpose: The study aimed to investigate passive range of motion (PROM) for rotation and lateral flexion, and muscle function of the cervical spine in children that had a history of CMT as infants. Study design: a prospective cohort study. Patient sample: 58 children at the age of 3.5 to 5 years that had been treated for CMT have infants participated in the study. Method: PROM was measured with protractors and muscle function was estimated with a modified Muscle Function Scale. Data from infancy were taken from earlier records. Result: PROM in rotation of the neck was mean 98.7° and PROM in lateral flexion of the neck was mean 69.1°. Symmetric PROM of the neck was found in 74% of the children for rotation and in 88% of the children for lateral flexion. Multiple regression showed that gender and PROM in rotation as infants had a significant impact on asymmetric PROM. Forty-five percent of the children had some degree of muscular imbalance in the lateral flexors of the neck. Conclusion: Possible risk factors for later asymmetric PROM are: gender, birth weight, gestation week and PROM in rotation as infants. These factors ought to be taken into consideration when developing guidelines for long-term follow-up.展开更多
As the elderly population continues to grow, the number of patients with low back pain is gradually increasing. Among them, Lumbar Degenerative Diseases (LDD) is one of the major contributors to low back pain. Biomech...As the elderly population continues to grow, the number of patients with low back pain is gradually increasing. Among them, Lumbar Degenerative Diseases (LDD) is one of the major contributors to low back pain. Biomechanical in vivo studies of the lumbar spine are mainly performed by implants or imaging data to record the real-time changes of form and stress on the intervertebral disc during motion. However, the current developments are slow due to the technological and ethical limitations. In vitro experiments include animal experiments and cadaver experiments, which are difficult to operate or differ greatly from normal human structures, and the results still need to be verified repeatedly to test their accuracy. As for finite element method, it is relatively low cost and can repeat the experimental results. Therefore, we believe that finite element analysis plays an extremely important role in biomechanical research, especially in analyzing the relationship between different surgical models and the degeneration caused by different mechanics.展开更多
目的研究Discover、Prodisc-C人工椎间盘置换术与植骨融合术后下颈椎活动度（range of motion,ROM）、椎间盘应力、韧带张力的生物力学特性以及植入假体力学性能的改变。方法建立C5-6椎间盘退变3种手术方案：Discover、Prodisc-C人工椎...目的研究Discover、Prodisc-C人工椎间盘置换术与植骨融合术后下颈椎活动度（range of motion,ROM）、椎间盘应力、韧带张力的生物力学特性以及植入假体力学性能的改变。方法建立C5-6椎间盘退变3种手术方案：Discover、Prodisc-C人工椎间盘置换和自体髂骨植骨融合有限元模型,同时建立C4-7节段下颈椎原始模型。分析术后下颈椎C4-7节段在矢状面、冠状面及横断面上椎体的生物力学特性变化。结果术后手术节段关节ROM变化：Discover模型增加12.7%-73.1%,Prodisc-C模型增加74%-98%,植骨融合模型下降55.8%-71.8%。Discover置换后上邻近椎间盘应力无明显增加,下邻近椎间盘应力在前屈、后伸、轴向旋转工况下减少33.2%-54.2%,囊韧带张力增幅比Prodisc-C置换后减少30%-40%。Discover假体最大应力（36.72 MPa）出现在前屈工况下,小于Prodisc-C假体的最大应力（42.66 MPa）。结论人工椎间盘置换术可以保留手术节段的运动性能,Discover作为新一代人工椎间盘假体,在减少韧带负担和维持脊柱稳定性方面有所进步。研究结果可为颈椎前路融合手术和人工颈椎间盘置换术的临床研究提供理论依据。展开更多
文摘Background: Infants with congenital muscular torticollis are born with an asymmetric range of motion and a muscular imbalance in the cervical spine, as a result of a shortening or excessive contraction of the sternocleidomastoid muscle. Purpose: The study aimed to investigate passive range of motion (PROM) for rotation and lateral flexion, and muscle function of the cervical spine in children that had a history of CMT as infants. Study design: a prospective cohort study. Patient sample: 58 children at the age of 3.5 to 5 years that had been treated for CMT have infants participated in the study. Method: PROM was measured with protractors and muscle function was estimated with a modified Muscle Function Scale. Data from infancy were taken from earlier records. Result: PROM in rotation of the neck was mean 98.7° and PROM in lateral flexion of the neck was mean 69.1°. Symmetric PROM of the neck was found in 74% of the children for rotation and in 88% of the children for lateral flexion. Multiple regression showed that gender and PROM in rotation as infants had a significant impact on asymmetric PROM. Forty-five percent of the children had some degree of muscular imbalance in the lateral flexors of the neck. Conclusion: Possible risk factors for later asymmetric PROM are: gender, birth weight, gestation week and PROM in rotation as infants. These factors ought to be taken into consideration when developing guidelines for long-term follow-up.
文摘As the elderly population continues to grow, the number of patients with low back pain is gradually increasing. Among them, Lumbar Degenerative Diseases (LDD) is one of the major contributors to low back pain. Biomechanical in vivo studies of the lumbar spine are mainly performed by implants or imaging data to record the real-time changes of form and stress on the intervertebral disc during motion. However, the current developments are slow due to the technological and ethical limitations. In vitro experiments include animal experiments and cadaver experiments, which are difficult to operate or differ greatly from normal human structures, and the results still need to be verified repeatedly to test their accuracy. As for finite element method, it is relatively low cost and can repeat the experimental results. Therefore, we believe that finite element analysis plays an extremely important role in biomechanical research, especially in analyzing the relationship between different surgical models and the degeneration caused by different mechanics.
文摘目的研究Discover、Prodisc-C人工椎间盘置换术与植骨融合术后下颈椎活动度（range of motion,ROM）、椎间盘应力、韧带张力的生物力学特性以及植入假体力学性能的改变。方法建立C5-6椎间盘退变3种手术方案：Discover、Prodisc-C人工椎间盘置换和自体髂骨植骨融合有限元模型,同时建立C4-7节段下颈椎原始模型。分析术后下颈椎C4-7节段在矢状面、冠状面及横断面上椎体的生物力学特性变化。结果术后手术节段关节ROM变化：Discover模型增加12.7%-73.1%,Prodisc-C模型增加74%-98%,植骨融合模型下降55.8%-71.8%。Discover置换后上邻近椎间盘应力无明显增加,下邻近椎间盘应力在前屈、后伸、轴向旋转工况下减少33.2%-54.2%,囊韧带张力增幅比Prodisc-C置换后减少30%-40%。Discover假体最大应力（36.72 MPa）出现在前屈工况下,小于Prodisc-C假体的最大应力（42.66 MPa）。结论人工椎间盘置换术可以保留手术节段的运动性能,Discover作为新一代人工椎间盘假体,在减少韧带负担和维持脊柱稳定性方面有所进步。研究结果可为颈椎前路融合手术和人工颈椎间盘置换术的临床研究提供理论依据。
