...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Journal of Biomechanics >How effective are added constraints in improving TKR kinematics?
【24h】

How effective are added constraints in improving TKR kinematics?

机译：改善TKR运动学的附加约束有多有效？

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Newer designs of total knee arthroplasty (TKA), through the use of added degrees of constraint, attempt to provide a '' guided motion '' to restore more normal and predictable kinematics. Two such design philosophies are the posterior stabilised (PS) using a cam-post and the medial pivot (MP) concepts. Knee kinematics of 12 patients with a PS TKA, 13 subjects with a MP TKA and 10 normal subjects were compared. For kinematic assessment, patients underwent fluoroscopic assessment of the knee during a step-up exercise and deep knee bend. Fluoroscopic images were corrected for distortion and assessed using 3D model fitting to determine relative 3D motion, and a 2D method to measure the patellar tendon angle (PTA) as function of knee flexion. For the PS design the cam-post mechanism engaged between 70 degrees and 100 degrees flexion. Between extension and 50 degrees there was forward motion of the contact points. Beyond 60 degrees both condyles rolled moved posteriorly. The majority of the external rotation of the femur Occurred between 50 degrees and 80 degrees. The PTA was lower than normal in extension and higher than normal in flexion. The MP exhibited no anterior movement throughout the rage of motion. The medial condyle moved minimally. The lateral contact point moved posteriorly from extension to flexion. The femur rotated externally throughout the range of flexion analysed. The PTA was similar to normal from extension to mid flexion and then higher than normal beyond to high flexion. The PS design fails to fully restrain paradoxical anterior movement and although the cam engages, it does not contribute significantly to overall rollback. The MP knee does not show significant anterior movement, the medial pivot concept appears to achieve near normal kinematics from extension to 50 degrees of knee flexion. However, the results show that at high flexion this design does not achieve normal knee kinematics. (c) 2007 Elsevier Ltd. All rights reserved.
机译：通过使用更多的约束度，较新的全膝关节置换术（TKA）设计试图提供“引导运动”以恢复更正常和可预测的运动学。两种这样的设计理念是使用凸轮柱的后稳定（PS）和中间枢轴（MP）概念。比较了12例PS TKA患者，13例MP TKA患者和10例正常受试者的膝关节运动学。为了进行运动学评估，对患者进行逐步运动和深屈膝时，应进行透视荧光检查。校正荧光镜图像的畸变，并使用3D模型拟合确定相对3D运动，并使用2D方法测量as屈肌腱角度（PTA）作为膝盖屈曲的函数进行评估。对于PS设计，凸轮柱机构可在70度到100度之间弯曲。在延伸和50度之间，接触点向前运动。超过60度，两个con骨向后滚动。股骨的大部分外部旋转发生在50度到80度之间。 PTA伸展程度低于正常水平，而屈曲程度高于正常水平。 MP在整个运动过程中均未显示前移。内侧con移动不大。侧面接触点从伸展到屈曲向后移动。在分析的整个屈曲范围内，股骨向外旋转。从伸展到屈曲中期，PTA与正常人相似，然后超出至高屈曲程度，PTA高于正常水平。 PS设计无法完全抑制自相矛盾的前向运动，尽管凸轮接合了，但对整体回滚没有太大贡献。 MP膝关节未显示明显的前向运动，内侧枢轴概念似乎从伸直到50度屈膝达到了接近正常的运动学。但是，结果表明，在高屈曲状态下，这种设计无法实现正常的膝关节运动学。 （c）2007 Elsevier Ltd.保留所有权利。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号