Sonenblum S E, Crisco J J, Kang L, Akelman E
Division of Engineering, Brown University, Providence, RI, USA.
J Biomech. 2004 May;37(5):645-52. doi: 10.1016/j.jbiomech.2003.09.033.
It has previously been shown that the articulation of the scaphotrapezio-trapezoidal (STT) joint can be modeled such that the trapezoid and trapezium are tightly linked and move together on a single path relative to the scaphoid during all directions of wrist motion. The simplicity of such a model is fascinating, but it leaves unanswered why two distinct carpal bones would have a mutually articulating surface if there were no motion between them, and how such a simplistic model of STT joint motion translates into the more complex global carpal motion. We performed an in vivo analysis of the trapezoids and trapeziums of 10 subjects (20 wrists) using a markerless bone registration technique. In particular, we analyzed the centroid spacing, centroid displacements, kinematics, and postures of the trapezoid and trapezium relative to the scaphoid. We found that, on a gross level, the in vivo STT motion was consistent with that reported in vitro. In addition, we found that the magnitude of trapezoid and trapezium motion was dependent upon the direction of wrist motion. However, we also found that when small rotations and displacements are considered there were small but statistically significant relative motions between the trapezoid and trapezium (0.4 mm in maximum flexion, 0.3 mm in radial deviation and at least 10 degrees in flexion extension and ulnar deviation) as well as slight off-path rotations. The results of this study indicate that the STT joint should be considered a mobile joint with motions more complex than previously appreciated.
先前的研究表明，舟大多角小多角（STT）关节的关节连接可以建模，使得大多角骨和小多角骨紧密相连，并在腕关节运动的所有方向上相对于舟骨在单一轨迹上共同移动。这种模型的简单性很吸引人，但它没有回答为什么如果两块不同的腕骨之间没有运动，它们会有相互连接的关节面，以及这样一个简单的STT关节运动模型如何转化为更复杂的整体腕骨运动。我们使用无标记骨配准技术对10名受试者（20个腕关节）的大多角骨和小多角骨进行了体内分析。特别是，我们分析了大多角骨和小多角骨相对于舟骨的质心间距、质心位移、运动学和姿势。我们发现，总体而言，体内STT运动与体外报道的一致。此外，我们发现大多角骨和小多角骨的运动幅度取决于腕关节运动的方向。然而，我们还发现，当考虑小旋转和位移时，大多角骨和小多角骨之间存在微小但具有统计学意义的相对运动（最大屈曲时为0.4毫米，桡偏时为0.3毫米，屈伸和尺偏时至少为10度）以及轻微的偏离轨迹旋转。这项研究的结果表明，STT关节应被视为一个活动关节，其运动比以前认识到的更为复杂。
