Hillen Robert J, Burger Bart J, Pöll Rudolf G, van Dijk C Niek, Veeger Dirkjan H E J
Waterland Hospital, Waterlandlaan 250, 1441 RN Purmerend, The Netherlands.
Clin Biomech (Bristol). 2012 Oct;27(8):777-81. doi: 10.1016/j.clinbiomech.2012.05.003. Epub 2012 May 29.
Malunion after mid shaft clavicle fractures has recently been recognized as a cause of pain and dysfunction of the shoulder. The mechanism that causes these complaints is however yet unclear. In this study we describe the kinematic changes that occur in the shoulder girdle due to clavicle shortening.
An experimental cadaveric study was performed on five shoulders of three fresh frozen specimens. The specimens were fixed in an upright position that allowed free motion of the shoulder girdle. We measured position of the bony structures with an opto-electronic system (Northern Digital Inc., Waterloo, Ontario Canada) in rest and during in a series of motions. Measurements were done with a normal clavicle and after shortening of the clavicle by 1.2, 2.4 and 3.6 cm. The shoulders were moved manually by one of the researchers. We examined for changes in resting position and during movement that resulted from the experimental shortening of the clavicle.
In the resting position, winging of the scapula increased with resultant changes in the orientation of the glenoid, acromio-clavicular and sterno-clavicular joints and an altered position of the clavicle. On average protraction increased by 20°, lateral rotation changed 12° and posterior tilt decreased by 7°. Clavicle shortening affected sterno-clavicular joint rotations but did not do so in the acromio-clavicular joint. In arm elevation the offset in scapula orientation at resting position stayed relatively constant over the full range of motion but the amount of disposition is progressive in relation to the amount of shortening.
Shortening of the clavicle leads to significant changes in the shoulder girdle in resting position and in movement.
锁骨中段骨折后畸形愈合近来被认为是肩部疼痛和功能障碍的一个原因。然而，导致这些症状的机制尚不清楚。在本研究中，我们描述了由于锁骨缩短而在肩胛带发生的运动学变化。
对三个新鲜冷冻标本的五个肩部进行了一项实验性尸体研究。标本被固定在一个直立位置，使肩胛带能够自由运动。我们使用光电系统（加拿大安大略省滑铁卢市北方数字公司）在静止和一系列运动过程中测量骨骼结构的位置。测量在正常锁骨以及锁骨分别缩短1.2厘米、2.4厘米和3.6厘米后进行。肩部由一名研究人员手动移动。我们检查了由于锁骨实验性缩短而导致的静止位置和运动过程中的变化。
在静止位置，肩胛骨翼状畸形增加，同时肩胛盂、肩锁关节和胸锁关节方向发生变化，锁骨位置改变。平均而言，前伸增加20°，外旋改变12°，后倾减少7°。锁骨缩短影响胸锁关节旋转，但不影响肩锁关节。在手臂抬高时，静止位置肩胛骨方向的偏移在整个运动范围内保持相对恒定，但相对于缩短量，移位量是渐进的。
锁骨缩短导致肩胛带在静止位置和运动时发生显著变化。
