Orth Marcel, Ganse Bergita, Andres Annchristin, Wickert Kerstin, Warmerdam Elke, Müller Max, Diebels Stefan, Roland Michael, Pohlemann Tim
Department of Trauma, Hand and Reconstructive Surgery, Saarland University, Saarbrücken, Germany.
Werner Siemens Endowed Chair of Innovative Implant Development (Fracture Healing), Saarland University, Saarbrücken, Germany.
Front Bioeng Biotechnol. 2023 Feb 20;11:1067845. doi: 10.3389/fbioe.2023.1067845. eCollection 2023.
Despite recent experimental and clinical progress in the treatment of tibial and fibular fractures, in clinical practice rates of delayed bone healing and non-union remain high. The aim of this study was to simulate and compare different mechanical conditions after lower leg fractures to assess the effects of postoperative motion, weight-bearing restrictions and fibular mechanics on the strain distribution and the clinical course. Based on the computed tomography (CT) data set of a real clinical case with a distal diaphyseal tibial fracture, a proximal and a distal fibular fracture, finite element simulations were run. Early postoperative motion data, recorded an inertial measuring unit system and pressure insoles were recorded and processed to study strain. The simulations were used to compute interfragmentary strain and the von Mises stress distribution of the intramedullary nail for different treatments of the fibula, as well as several walking velocities (1.0 km/h; 1.5 km/h; 2.0 km/h) and levels of weight-bearing restriction. The simulation of the real treatment was compared to the clinical course. The results show that a high postoperative walking speed was associated with higher loads in the fracture zone. In addition, a larger number of areas in the fracture gap with forces that exceeded beneficial mechanical properties longer was observed. Moreover, the simulations showed that surgical treatment of the distal fibular fracture had an impact on the healing course, whereas the proximal fibular fracture barely mattered. Weight-bearing restrictions were beneficial in reducing excessive mechanical conditions, while it is known that it is difficult for patients to adhere to partial weight-bearing recommendations. In conclusion, it is likely that motion, weight bearing and fibular mechanics influence the biomechanical milieu in the fracture gap. Simulations may improve decisions on the choice and location of surgical implants, as well as give recommendations for loading in the postoperative course of the individual patient.
尽管近期在胫腓骨骨折治疗方面取得了实验和临床进展，但在临床实践中，骨愈合延迟和骨不连的发生率仍然很高。本研究的目的是模拟和比较小腿骨折后的不同力学条件，以评估术后运动、负重限制和腓骨力学对应变分布和临床病程的影响。基于一个真实临床病例的计算机断层扫描（CT）数据集，该病例为胫骨干骺端远端骨折、近端和远端腓骨骨折，进行了有限元模拟。记录并处理了早期术后运动数据，这些数据由惯性测量单元系统和压力鞋垫记录，以研究应变。模拟用于计算不同腓骨治疗方式、几种步行速度（1.0 km/h；1.5 km/h；2.0 km/h）和负重限制水平下髓内钉的骨折块间应变和冯·米塞斯应力分布。将真实治疗的模拟结果与临床病程进行比较。结果表明，术后高步行速度与骨折区域的更高负荷相关。此外，观察到骨折间隙中更多区域的力超过有益力学性能的时间更长。而且，模拟表明远端腓骨骨折的手术治疗对愈合过程有影响，而近端腓骨骨折影响不大。负重限制有利于减少过度的力学条件，然而众所周知，患者很难遵守部分负重的建议。总之，运动、负重和腓骨力学可能会影响骨折间隙的生物力学环境。模拟可以改善手术植入物选择和位置的决策，并为个体患者术后的负荷提供建议。
