Elastographic imaging of strain distribution in the anterior cruciate ligament and at the ligament-bone insertions
Elastographic imaging of strain distribution in the anterior cruciate ligament and at the ligament-bone insertions
复制标题
DOI：
10.1002/jor.20260
复制
发表时间：
2006-10-01
影响因子：
2.8
通讯作者：
Lu, Helen H.
中科院分区：
文献类型：
--
作者：
Spalazzi, Jeffrey P.;Gallina, Jason;Lu, Helen H.
前十字韧带 (ACL) 充当胫股关节的机械稳定器，是最常受伤的膝关节韧带。为了改善用于 ACL 重建的肌腱移植物的临床效果，我们的长期目标是通过天然韧带-骨界面的再生促进移植物-骨整合。了解该界面的应变分布对于功能支架设计和临床评估至关重要。然而，由于插入位点的长度尺度较小，实验测定一直很困难。本研究利用超声弹性成像来表征 ACL 和 ACL-骨界面在张力下的反应。具体来说，将牛胫股关节安装在材料测试系统上并承受张力，同时以 5 MHz 采集射频 (RF) 数据。使用互相关和再相关技术生成 RF 框架和参考框架之间的轴向应变弹性图。弹性成像分析表明，当关节承受张力时，胫骨插入处会出现具有压缩和拉伸成分的复杂应变，并且在插入部位发现更高的应变。此外，ACL 本身的位移最大，从韧带到骨位移值逐渐减小，可能反映了韧带-骨界面处的基质组织。我们的结果表明，弹性成像是一种新方法，可轻松用于表征 ACL 及其插入骨的机械特性。 (c) 2006 年骨科研究学会。
The anterior cruciate ligament (ACL) functions as a mechanical stabilizer in the tibiofemoral joint, and is the most commonly injured knee ligament. To improve the clinical outcome of tendon grafts used for ACL reconstructions, our long-term goal is to promote graft-bone integration via the regeneration of the native ligament-bone interface. An understanding of strain distribution at this interface is crucial for functional scaffold design and clinical evaluation. Experimental determination, however, has been difficult due to the small length scale of the insertion sites. This study utilizes ultrasound elastography to characterize the response of the ACL and ACL-bone interface under tension. Specifically, bovine tibiofemoral joints were mounted on a material testing system and loaded in tension while radiofrequency (RF) data were acquired at 5 MHz. Axial strain elastograms between RF frames and a reference frame were generated using crosscorrelation and recorrelation techniques. Elastographic analyses revealed that when the joint was loaded in tension, complex strains with both compressive and tensile components occurred at the tibial insertion, with higher strains found at the insertion sites. In addition, the displacement was greatest at the ACL proper and decreased in value gradually from ligament to bone, likely a reflection of the matrix organization at the ligament-bone interface. Our results indicate that elastography is a novel method that can be readily used to characterize the mechanical properties of the ACL and its insertions into bone. (c) 2006 Orthopaedic Research Society.