目的:在眼科手术中,不同的材料和固定方法用于外侧眼眶切开术(LOA)后的骨瓣重新定位,然而没有统一的标准。本研究旨在通过对LOA中眶缘固定的生物力学环境进行有限元分析(FEA)模拟,研究不同固定策略对眼眶稳定性的影响。
方法:建立并验证了有限元模型(FEM),以使用单个钛板模拟常规外侧眼眶切开术(CLOA)和深外侧眼眶减压(DLOD)在各种载荷下的力学响应,双层钛板,和双可吸收钢板的固定方法。然后针对临床病例验证模拟。
结果:在类似条件下,钛合金固定件的最大等效应力(MES)大于可吸收板材料。在静态和生理条件下,所有FEM组确保了系统的结构稳定性,材料应力保持在安全范围内。与CLOA相比,DLOD,这涉及到移除外侧轨道壁,改变应力传导,导致MES和最大总变形(MTD)分别增加1.96和2.62倍,分别。在50N的水平载荷下,有限元/DLOD中的MES超过了材料自身的强度,随着MES和MTD分别增长3.18和6.64倍,分别,与FEM/CLOA相比。在50N的垂直力下,每个FEM维持的MES都在安全范围内。骨瓣旋转角度在不同情况下保持最小变化。随访期间,本研究中验证的12例患者未出现与内固定装置相关的并发症.
结论:在静态或生理条件下,各种固定方法可以有效维持眼眶切开术部位的稳定性,和可吸收材料,具有更平滑的应力传递特性,更适合在CLOA中应用。在钛板固定件中,单钛板可以更好地承受垂直应力,而双钛板更能够处理水平应力。考虑到由于DLOD引起的轨道力学行为的变化,骨瓣复位应考虑增强固定强度。
OBJECTIVE: In ophthalmic surgery, different materials and fixation methods are employed for bone flap repositioning after lateral orbitotomy approach (LOA), yet there is no unified standard. This study aims to investigate the impact of different fixation strategies on orbital stability through Finite Element Analysis (FEA) simulations of the biomechanical environment for orbital rim fixation in LOA.
METHODS: A Finite Element Model (FEM) was established and validated to simulate the mechanical responses under various loads in conventional lateral orbitotomy approach (CLOA) and deep lateral orbital decompression (DLOD) using single titanium plate, double titanium plates, and double absorbable plates fixation methods. The simulations were then validated against clinical cases.
RESULTS: Under similar conditions, the maximum equivalent stress (MES) on titanium alloy fixations was greater than that on absorbable plate materials. Both under static and physiological conditions, all FEM groups ensured structural stability of the system, with material stresses remaining within safe ranges. Compared to CLOA, DLOD, which involves the removal of the lateral orbital wall, altered stress conduction, resulting in an increase of MES and maximum total deformation (MTD) by 1.96 and 2.62 times, respectively. Under a horizontal load of 50 N, the MES in FEM/DLOD exceeded the material\'s own strength, with an increase in MES and MTD by 3.18 and 6.64 times, respectively, compared to FEM/CLOA. Under a vertical force of 50 N, the MES sustained by each FEM was within safe limits. Bone flap rotation angles remained minimally varied across scenarios. During follow-up, the 12 patients validated in this study did not experience complications related to the internal fixation devices.
CONCLUSIONS: Under static or physiological conditions, various fixation methods can effectively maintain stability at the orbitotomy site, and absorbable materials, with their smoother stress transmission properties, are more suited for application in CLOA. Among titanium plate fixations, single titanium plates can better withstand vertical stress, while double titanium plates are more capable of handling horizontal stress. Given the change in the orbital mechanical behavior due to DLOD, enhanced fixation strength should be considered for bone flap repositioning.