Kikuchi Kazuma, Itoi Eiji, Yamamoto Nobuyuki, Seki Nobutoshi, Abe Hidekazu, Minagawa Hiroshi, Shimada Yoichi
Division of Orthopedic Surgery, Department of Neuro and Locomotor Science, Akita University School of Medicine, Akita, Japan.
J Orthop Sci. 2008 Jan;13(1):72-7. doi: 10.1007/s00776-007-1186-2. Epub 2008 Feb 16.
In shoulders with multidirectional instability, translation of the humeral head on the glenoid is increased in the midrange because of the following three reasons: the increased retroversion, a hypoplastic posteroinferior rim, and decreased scapular abduction during arm elevation. This study aimed to clarify the relationship between glenoid inclination and glenohumeral joint stability.
Nine fresh-frozen cadaveric shoulders were tested. With a 50-N compressive load, the translation force was measured in the 3-o'clock, 6-o'clock, 9-o'clock, and 12-o'clock directions by using a tilt of 0 degrees , 5 degrees , 10 degrees , 15 degrees , and 20 degrees . When the glenoid was tilted in one direction, the translation force was measured in the direction of inclination and in the opposite direction. The stability ratio was then calculated.
The stability ratio in the 3-o'clock direction significantly decreased with a tilt of more than 5 degrees in the 3-o'clock direction. The stability ratio in the 9-o'clock direction significantly decreased with a tilt of more than 15 degrees in the 9-o'clock direction and significantly increased with a tilt of more than 5 degrees in the 3-o'clock direction. The stability ratio in the 6-o'clock direction significantly increased with a tilt of more than 10 degrees in the 6-o'clock direction.
The posterior and inferior stability increased with an anterior tilt of more than 5 degrees and with a superior tilt of 10 degrees , respectively. The anterior and posterior stability decreased with an anterior tilt of 5 degrees and with a posterior tilt of 15 degrees , respectively.
在多向不稳定的肩部，由于以下三个原因，肱骨头在关节盂上的平移在中间范围内会增加：后倾增加、后下盂缘发育不全以及手臂抬高时肩胛骨外展减少。本研究旨在阐明关节盂倾斜与盂肱关节稳定性之间的关系。
对九个新鲜冷冻的尸体肩部进行测试。在50牛的压缩负荷下，通过使用0度、5度、10度、15度和20度的倾斜度，在3点、6点、9点和12点方向测量平移力。当关节盂向一个方向倾斜时，在倾斜方向和相反方向测量平移力。然后计算稳定性比率。
在3点方向倾斜超过5度时，3点方向的稳定性比率显著降低。在9点方向倾斜超过15度时，9点方向的稳定性比率显著降低，而在3点方向倾斜超过5度时，稳定性比率显著增加。在6点方向倾斜超过10度时，6点方向的稳定性比率显著增加。
后倾超过5度和上倾10度时，后下方稳定性分别增加。前倾5度和后倾15度时，前、后稳定性分别降低。
