Gardner T N, Simpson H, Kenwright J
Oxford Orthopaedic Engineering Centre, Nuffield Orthopaedic Centre, Windmill Road, Headington, Oxford OX3 7LD, UK.
Clin Biomech (Bristol). 2001 Feb;16(2):151-9. doi: 10.1016/s0268-0033(00)00071-1.
This study evaluates the mechanical performance of the Pinless and Centrafix fixators for rapid application to tibial fractures in a disaster or battlefield scenario.
Comparative study based on measurements made in the laboratory.
The Pinless and Centrafix fixators may be considered for rapid application to stabilise fractures in emergency conditions without the aid of electrical equipment such as power drills for bone screw insertion or image intensifiers to facilitate bone alignment.
Stiffnesses, maximum service loads and fatigue strengths of the fixators were measured in the orientations of loading that correspond to walking and stretcher-bearing. These properties were compared with measurements on three conventional fixators, the AO, Shearer and Triax.
The Centrafix stiffnesses were 31 N/mm (axial), 1 N/ degrees (torsional shear), 0.4 N/ degrees (coronal plane bending), 4 N/ degrees (sagittal plane bending) and 11 N/mm (transverse shear) and strengths were 95 N (axial) and 1.9 Nm (bending). Corresponding Pinless stiffnesses were 43 N/mm, 0.7 N/ degrees, 0.3 N/ degrees, 8 N/ degrees and 50 N/mm, and strength was 55 N (axial).
The stiffness and strength of both rapid application fixators in simulated walking was judged to be low, and additionally the stiffness and strength of the Centrafix in simulated stretcher-bearing was judged to be low.
The Pinless is not recommended for weight-bearing subjects with unstable fractures. The Centrafix is not recommended for stretcher-bearing or weight-bearing with unstable fractures.
本研究评估无针式和中心固定型外固定器在灾难或战场场景中快速应用于胫骨骨折时的力学性能。
基于实验室测量的对比研究。
无针式和中心固定型外固定器可考虑在紧急情况下快速应用，以稳定骨折，无需借助诸如用于插入骨螺钉的电钻或用于辅助骨对齐的影像增强器等电气设备。
在对应行走和担架搬运的加载方向上测量外固定器的刚度、最大使用载荷和疲劳强度。将这些性能与三种传统外固定器（AO、希勒和Triax）的测量结果进行比较。
中心固定型外固定器的刚度分别为轴向31N/mm、扭剪1N/度、冠状面弯曲0.4N/度、矢状面弯曲4N/度和横向剪切11N/mm，强度分别为轴向95N和弯曲1.9Nm。相应的无针式外固定器刚度分别为43N/mm、0.7N/度、0.3N/度、8N/度和50N/mm，轴向强度为55N。
两种快速应用外固定器在模拟行走时的刚度和强度被判定为较低，此外，中心固定型外固定器在模拟担架搬运时的刚度和强度也被判定为较低。
不建议无针式外固定器用于骨折不稳定的负重患者。不建议中心固定型外固定器用于骨折不稳定的担架搬运或负重患者。
