Cox L G, Dahners L E, Gilbert J A
University of North Carolina, Chapel Hill 27599-7055.
Clin Orthop Relat Res. 1989 Jun(243):189-94.
The rigidity and strength of fixation of experimental spiral fractures in canine tibias with triple lag-screw osteosynthesis were compared with fixation by six-hole dynamic compression plating (DCP). Lag-screw fixation was 71% to 77% as stiff in bending and 69% as stiff in torsion as plate fixation. When evaluated by torsion to failure, lag-screw specimens were 68% as strong as plate specimens. Although the difference in energy to failure in torsion was not statistically significant between the two methods, both fell considerably short of control values. The lag preparation was 9% as strong as intact controls, and the plate preparation was 21% as strong as intact controls. Long spiral fractures without comminution are amenable to triple lag-screw osteosynthesis with some loss of rigidity and strength when compared to single-plate fixation. This decrease in rigidity and strength may be outweighed by the avoidance of the stress protection phenomenon noted under rigid plates.
将犬胫骨实验性螺旋骨折采用三枚拉力螺钉骨合成的固定刚度和强度与六孔动力加压接骨板（DCP）固定进行比较。拉力螺钉固定在弯曲时的刚度为接骨板固定的71%至77%，在扭转时的刚度为接骨板固定的69%。通过扭转至失效评估时，拉力螺钉标本的强度为接骨板标本的68%。尽管两种方法在扭转失效能量方面的差异无统计学意义，但两者均远低于对照值。拉力螺钉固定组的强度为完整对照组的9%，接骨板固定组的强度为完整对照组的21%。与单接骨板固定相比，无粉碎的长螺旋骨折适合采用三枚拉力螺钉骨合成，但会有一定的刚度和强度损失。这种刚度和强度的降低可能会被避免刚性接骨板下出现的应力保护现象所抵消。
