Department of Biomedical Engineering, University of Delaware, Newark, Delaware, USA.
Department of Mechanical Engineering, University of Wisconsin, Madison, Wisconsin, USA.
J Orthop Res. 2023 Oct;41(10):2315-2321. doi: 10.1002/jor.25654. Epub 2023 Jul 10.
The Achilles tendon consists of three subtendons that transmit force from the triceps surae muscles to the calcaneus. Individual differences have been identified in Achilles subtendon morphology and twist in cadavers, which may have implications for triceps surae mechanics and function. High-field magnetic resonance imaging (MRI) can be used to identify boundaries within multi-bundle tissues, which could then enable studies of subtendon structure-function relationships in humans. The objective of this study was to use high-field MRI (7T) to image and reconstruct Achilles subtendons arising from the triceps surae muscles. We imaged the dominant lower leg of a cohort of healthy human subjects (n = 10) using a tuned musculoskeletal sequence (double echo steady state sequence, 0.4 mm isotropic voxels). We then characterized the cross-sectional area and orientation of each subtendon between the MTJ and calcaneal insertion. Image collection and segmentation was repeated to assess repeatability. Subtendon morphometry varied across subjects, with average subtendon areas of 23.5 ± 8.9 mm for the medial gastrocnemius, 25.4 ± 8.9 mm for the lateral gastrocnemius, and 13.7 ± 5.9 mm for the soleus subtendons. Repeatable subject-specific variations in size and position of each subtendon were identified over two visits, expanding on prior knowledge that high variability exists in Achilles subtendon morphology across subjects.
跟腱由三个次级腱组成,它们将三头肌的力量传递到跟骨。在尸体中已经确定了跟腱次级腱形态和扭转的个体差异,这可能对三头肌力学和功能有影响。高磁场磁共振成像(MRI)可用于识别多束组织内的边界,从而能够在人类中研究次级腱的结构-功能关系。本研究的目的是使用高磁场 MRI(7T)成像和重建来自三头肌的跟腱次级腱。我们使用调谐的肌肉骨骼序列(双回波稳态序列,0.4mm 各向同性体素)对一组健康人体受试者的优势小腿(n=10)进行成像。然后,我们描述了 MTJ 和跟骨插入处之间每个次级腱的横截面积和方向。重复图像采集和分割以评估可重复性。次级腱形态学在受试者之间存在差异,内侧腓肠肌的平均次级腱面积为 23.5±8.9mm,外侧腓肠肌为 25.4±8.9mm,比目鱼肌为 13.7±5.9mm。在两次就诊中,确定了每个次级腱的大小和位置的可重复的个体差异,这扩展了之前的知识,即跟腱次级腱形态在个体之间存在高度的可变性。