Paley D, Fleming B, Catagni M, Kristiansen T, Pope M
University of Maryland Hospital, Baltimore, Division of Orthopaedic Surgery 21201.
Clin Orthop Relat Res. 1990 Jan(250):50-7.
Four external fixator systems (five configurations) used for limb lengthening were tested to determine the fixator stiffness and the fracture gap rigidity. There was a statistical difference between fixators in all modes of loading with respect to stiffness, shear, and axial motion. The fixators were graded to determine their relative stiffness, shear rigidity, and axial rigidity. The EBI Orthofix proved to be the most rigid fixator relative to the configurations tested with minimal shear or axial motion at the fracture site. The Ilizarov tibial configuration was the least rigid, demonstrating more shear and axial motion at the fracture gap. The Ilizarov femoral system combined excellent stability and shear resistance with preservation of axial dynamization. Fixators with a high stiffness provide less motion at the fracture site, which may cause stress shielding of the osteotomy. Fixators that provide more motion at the fracture gap are less stable. These data may be useful in determining which fixator may be ideal for a particular clinical situation.
对用于肢体延长的四种外固定系统（五种构型）进行了测试，以确定固定器的刚度和骨折间隙的刚性。在所有加载模式下，固定器在刚度、剪切力和轴向运动方面存在统计学差异。对固定器进行分级以确定其相对刚度、剪切刚性和轴向刚性。相对于所测试的构型，EBI Orthofix被证明是最刚性的固定器，在骨折部位的剪切或轴向运动最小。伊里扎洛夫胫骨构型的刚性最小，在骨折间隙处表现出更多的剪切和轴向运动。伊里扎洛夫股骨系统结合了出色的稳定性和抗剪切性，并保留了轴向动力化。具有高刚度的固定器在骨折部位提供的运动较少，这可能会导致截骨处的应力遮挡。在骨折间隙提供更多运动的固定器稳定性较差。这些数据可能有助于确定哪种固定器可能最适合特定的临床情况。
