Fitzpatrick D C, Marsh J L, Brown T D
Department of Orthopaedic Surgery, University of Iowa, Iowa City 52242, USA.
J Orthop Trauma. 1995 Feb;9(1):76-82. doi: 10.1097/00005131-199502000-00012.
The effect of the Orthofix articulated ankle external fixator on ankle and subtalar joint kinematics and fracture fragment motion was investigated in fresh cadaver specimens using biplanar radiographic analysis. The kinematic testing was performed for the normal ankle (i.e., no fixation) and for three alternate fixator hinge orientations. The fixator applications simulated a horizontal ankle axis (the current clinically preferred orientation), an axis coincident with a previously defined approximate ankle axis, and an axis located using a mechanical axis finder. The horizontal fixator application significantly disturbed normal ankle kinematics. Aligning the fixator hinge with an approximate ankle axis caused significant distortion of motion about only two of six possible rotational axes. Aligning the fixator hinge with the (specimen-specific) ankle axis determined by the axis finder most closely matched the motion of the normal ankle. For pilon fractures simulated by a transverse osteotomy, there appeared to be no physiologically significant fracture fragment motions, regardless of fracture stability or fixator orientation.
采用双平面放射学分析，在新鲜尸体标本中研究了Orthofix铰接式踝关节外固定器对踝关节和距下关节运动学以及骨折块运动的影响。对正常踝关节（即无固定）和三种不同的固定器铰链方向进行了运动学测试。固定器的应用模拟了水平踝关节轴（当前临床首选方向）、与先前定义的近似踝关节轴重合的轴以及使用机械轴探测器确定的轴。水平应用固定器显著干扰了正常踝关节的运动学。将固定器铰链与近似踝关节轴对齐仅导致六个可能旋转轴中的两个运动发生显著扭曲。将固定器铰链与由轴探测器确定的（特定标本的）踝关节轴对齐最接近正常踝关节的运动。对于通过横向截骨模拟的pilon骨折，无论骨折稳定性或固定器方向如何，似乎都没有生理上显著的骨折块运动。
