梯形骨盆骨外固定器治疗骨盆骨折脱位的生物力学评价

The biomechanical study on the treatment of pelvis fracture and dislocation using trapezoid external fixator

目的 :探讨梯形骨盆骨外固定器对骨盆骨折与脱位的生物力学机理 ,促进骨盆骨外固定器的进一步推广和应用。方法 :应用材料力学试验系统及Prescale压力胶片对 5个骨盆骨外固定器固定前后的骨盆标本进行生物力学测试。结果 :骨盆骨外固定器被固定后 ,骨折处prescale压力胶片可测到压力 ,且前环大于后环 ,骨外固定系统的刚度前、后环分别是 ( 1 7.6 0± 0 .97)、( 2 .2 3± 0 .2 1 )N/mm(P <0 .0 1 )。结论 :梯形骨盆骨外固定器可给被固定的骨盆提供一个额状面的力 ,该力可同时作用于前、后环 ,其中前环明显大于后环 ,故前环损伤的固定刚度大于后环。即梯形骨盆骨外固定器可治疗骨盆骨折和脱位 ,特别是前环损伤或 /和伴有额状面移位的患者。

Objective:To provide biomechanical theory of trapezoid external fixator for pelvis fracture and dislocation and to promote its clinical application furthermore.Methods:Five cadaveric pelvis fracture specimens were biomechanically tested with material testing system and Prescale compression traces before and after the external fixator was fixed.Results:The Prescale compression traces were printed after external fixator was fixed;the traces in anterior ring were markedly heavier than those in posterior ring.The value of external fixation rigidity in anterior and posterior ring was 17.60±0.97, 2.23±0.21 N/mm( P <0.01)respectiveily.Conclusions:The frontal force is provided by compressive external fixator and simultaneously conveyed to anterior and posterior rings.The force in anterior ring is stronger than that in posterior,so the stiffness of external fixator for anterior ring disruption is significantly stronger than that in posterior.As a result,the trapezoid external fixator could treat pelvis fracture and dislocation,especially the trauma in the anterior ring disruption with coronal displacement.