Kitamura Takashi, Moritomo Hisao, Arimitsu Sayuri, Berglund Lawrence J, Zhao Kristin D, An Kai-Nan, Rizzo Marco
Biomechanics Laboratory, Division of Orthopedic Research, Mayo Clinic, Rochester, MN 55905, USA.
J Hand Surg Am. 2011 Oct;36(10):1626-30. doi: 10.1016/j.jhsa.2011.07.016. Epub 2011 Aug 26.
The distal interosseous membrane (DIOM) is a secondary stabilizer of the distal radioulnar joint (DRUJ) and has a considerably variable morphology. The purpose of this study was to investigate whether innate DRUJ stability is influenced by the anatomic variation of the DIOM.
Ten fresh-frozen cadaver upper extremities were used in this study. The humerus and the ulna were affixed rigidly to a custom-made apparatus, with the elbow in 90° of flexion. Testing was performed by translating the radius in volar and dorsal directions relative to the ulna, with a 20-N applied force in neutral forearm alignment, 60° pronation, and 60° supination. Total translation of the radius was measured as DRUJ laxity. After the experiment, we investigated anatomic variation of the DIOM, especially regarding the existence of the distal oblique bundle (DOB), which is a notably thick fiber within the DIOM. We compared the DRUJ stability between the groups with and without the DOB.
The DOB was found in 4 of 10 specimens. The group with a DOB demonstrated a significantly greater DRUJ stability in the neutral position than the group without a DOB. In pronated and supinated forearm positions, no significant difference in DRUJ stability was obtained between the groups with and without a DOB.
Innate DRUJ stability in the neutral forearm position was greater in the group with a DOB than in those without a DOB.
This study suggests that considerable variation exists in DRUJ laxity and that it partially depends on anatomical variations of the DIOM.
远侧骨间膜（DIOM）是桡尺远侧关节（DRUJ）的次要稳定结构，其形态变化较大。本研究旨在探讨DIOM的解剖变异是否会影响DRUJ的固有稳定性。
本研究使用了10具新鲜冷冻的尸体上肢。将肱骨和尺骨牢固地固定在定制装置上，使肘部处于90°屈曲位。测试时，在前臂中立位、旋前60°和旋后60°的情况下，以20 N的作用力使桡骨相对于尺骨在掌侧和背侧方向平移。测量桡骨的总平移量作为DRUJ的松弛度。实验结束后，我们研究了DIOM的解剖变异，特别是远侧斜束（DOB）的存在情况，DOB是DIOM内一条明显较粗的纤维束。我们比较了有DOB和无DOB两组之间的DRUJ稳定性。
在10个标本中有4个发现了DOB。有DOB的组在中立位时DRUJ稳定性明显高于无DOB的组。在前臂旋前和旋后位时，有DOB和无DOB的组之间DRUJ稳定性无显著差异。
在前臂中立位时，有DOB的组DRUJ的固有稳定性高于无DOB的组。
本研究表明DRUJ的松弛度存在很大差异，且部分取决于DIOM的解剖变异。
