Department of Orthopaedic Surgery, Dokkyo Medical University Saitama Medical Center, 2-1-50, Minamikoshigaya, Koshigaya, Saitama, Japan.
Clinical and Research Institute for Foot and Ankle Surgery, 341-1, Mangoku, Kisarazu, 292-0003, Chiba, Japan.
BMC Musculoskelet Disord. 2021 Feb 20;22(1):208. doi: 10.1186/s12891-021-04058-2.
Measuring the strain patterns of ligaments at various joint positions informs our understanding of their function. However, few studies have examined the biomechanical properties of ankle ligaments; further, the tensile properties of each ligament, during motion, have not been described. This limitation exists because current biomechanical sensors are too big to insert within the ankle. The present study aimed to validate a novel miniaturized ligament performance probe (MLPP) system for measuring the strain patterns of the anterior talofibular ligament (ATFL) during ankle motion.
Six fresh-frozen, through-the-knee, lower extremity, cadaveric specimens were used to conduct this study. An MLPP system, comprising a commercially available strain gauge (force probe), amplifier unit, display unit, and logger, was sutured into the midsubstance of the ATFL fibers. To measure tensile forces, a round, metal disk (a "clock", 150 mm in diameter) was affixed to the plantar aspect of each foot. With a 1.2-Nm load applied to the ankle and subtalar joint complex, the ankle was manually moved from 15° dorsiflexion to 30° plantar flexion. The clock was rotated in 30° increments to measure the ATFL strain detected at each endpoint by the miniature force probe. Individual strain data were aligned with the neutral (0) position value; the maximum value was 100.
Throughout the motion required to shift from 15° dorsiflexion to 30° plantar flexion, the ATFL tensed near 20° (plantar flexion), and the strain increased as the plantar flexion angle increased. The ATFL was maximally tensioned at the 2 and 3 o'clock (inversion) positions (96.0 ± 5.8 and 96.3 ± 5.7) and declined sharply towards the 7 o'clock position (12.4 ± 16.8). Within the elastic range of the ATFL (the range within which it can return to its original shape and length), the tensile force was proportional to the strain, in all specimens.
The MLPP system is capable of measuring ATFL strain patterns; thus, this system may be used to effectively determine the relationship between limb position and ATFL ankle ligament strain patterns.
测量不同关节位置下的韧带应变模式有助于我们了解其功能。然而，很少有研究探讨踝关节韧带的生物力学特性；此外，在运动过程中，各韧带的拉伸特性尚未被描述。这一局限性的存在是因为当前的生物力学传感器太大，无法插入踝关节内。本研究旨在验证一种新型的微型化韧带性能探头（MLPP）系统，用于测量踝关节运动过程中距腓前韧带（ATFL）的应变模式。
本研究使用了 6 个新鲜冷冻、膝关节以下、尸体标本。一个 MLPP 系统，包括一个市售的应变计（力探头）、放大器单元、显示单元和记录器，被缝合到 ATFL 纤维的中体部分。为了测量拉伸力，在每个脚的足底附着一个圆形金属盘（“时钟”，直径 150 毫米）。在踝关节和距下关节复合体上施加 1.2-Nm 的负荷，手动将踝关节从 15°背屈移动到 30°跖屈。时钟以 30°的增量旋转，以测量微型力探头在每个端点检测到的 ATFL 应变。各个应变数据与中性（0）位置值对齐；最大值为 100。
在从 15°背屈到 30°跖屈的运动过程中，ATFL 在近 20°（跖屈）处拉紧，并且随着跖屈角度的增加，应变增加。ATFL 在 2 点和 3 点（内翻）位置最大拉紧（96.0 ± 5.8 和 96.3 ± 5.7），并急剧下降到 7 点位置（12.4 ± 16.8）。在 ATFL 的弹性范围内（其可以恢复到原始形状和长度的范围），所有标本中，拉伸力与应变成正比。
MLPP 系统能够测量 ATFL 应变模式；因此，该系统可用于有效确定肢体位置与 ATFL 踝关节韧带应变模式之间的关系。
