Marasco Silvana F, Sutalo Ilija D, Bui Anh V
CJOB Cardiothoracic Surgery Department, The Alfred Hospital, Melbourne, Victoria, Australia.
J Trauma. 2010 May;68(5):1225-33. doi: 10.1097/TA.0b013e3181d27cab.
Rib fractures as a result of trauma are a relatively common injury. There is an increasing interest in the operative stabilization of these injuries. Absorbable fixation plates are an option for improved rib fracture treatment. The aim of this study was to review our plating failures and to create a numerical model of muscle forces on fractured ribs to identify the mechanism by which these rib fixations have failed.
Thirteen patients who had 58 ribs fixed with absorbable prostheses were reviewed. Finite element modeling was used to simulate the fixation of a lateral rib fracture using an absorbable plate and screw system. Internal pressure, intercostal forces, and appropriate displacement and rotational constraints were enforced at the rib ends.
Ten rib fixation failures were noted in the clinical series. The modeling results showed that stresses on the plate differ during inspiration and expiration. Failure to use the two central screws resulted in higher stresses on the plating system. During inspiration simulations, the screws on both rib parts are active in keeping the rib and plate surfaces unseparated. However, during expiration, there is a greater stress on the screws on the posterior part of the broken rib, and separation of the plate from the rib seems to be more likely to occur at this site.
This study indicates that the likely mode of failure of this absorbable plating system occurs on the posterior part of the rib, which correlates with the clinical failures seen.
创伤导致的肋骨骨折是一种相对常见的损伤。人们对这些损伤的手术稳定治疗的兴趣日益增加。可吸收固定钢板是改善肋骨骨折治疗的一种选择。本研究的目的是回顾我们的钢板固定失败情况，并建立一个关于骨折肋骨上肌肉力量的数值模型，以确定这些肋骨固定失败的机制。
回顾了13例使用可吸收假体固定58根肋骨的患者。采用有限元建模来模拟使用可吸收钢板和螺钉系统对外侧肋骨骨折的固定。在肋骨两端施加内压、肋间力以及适当的位移和旋转约束。
临床系列中发现10例肋骨固定失败。建模结果表明，在吸气和呼气过程中，钢板上的应力不同。未使用两个中央螺钉会导致钢板系统上的应力更高。在吸气模拟过程中，肋骨两部分上的螺钉都有助于保持肋骨和钢板表面不分离。然而，在呼气过程中，骨折肋骨后部的螺钉上的应力更大，并且钢板与肋骨在此部位似乎更有可能分离。
本研究表明，这种可吸收钢板固定系统可能的失败模式发生在肋骨后部，这与观察到的临床失败情况相关。
