眶颧颌骨折修复材料和内固定方式选择的生物力学研究

Zygomatic-orbito-maxillary fracture is a kind of complex orbital fracture of high morbidity, which can lead to severe physical dysfunction and deformity. Meanwhile the process of surgical reconstruction and repair is extremely complicated. Currently the use of computer assisted design and intraoperative navigation have obviously increased the accuracy of bone fracture reduction. But there is still no objective and quantitive approach to decide the most suitable implant and method for internal fixation. Instead merely basing on the clinical experience can lead to the complication like implant malposition and breakage. Because the force distribution on fracture ends is significant for the choosing of personalized method for orbital reconstruction. This research intends to deduce an correction formula which can clarify the relationship between periorbital force with age, gender, muscle cross-sectional area and muscle CT density through experimental procedure, hence calculating the periorbital force which was exerted on the orbit under postoperative physical conditions. Based on this, build the zygomatic-orbito-maxillary internal fixation numerical model with finite element analysis technology. Then combined with the biomechanical characteristics of orbital bone tissue and implants, analyse the stress distribution, deformation and displacement of the implant, so as to provide an objective and quantitive basis for the choosing of implant and internal fixation method for zygomatic-orbito-maxillary fracture, guide clinical treatment precisely and achieve stable structural and functional restoration.

眶颧颌骨折是发病率较高的复合型眼眶骨折，严重影响患者的生理功能和外观，其修复及重建过程相对复杂。目前随着计算机辅助设计、制造及导航技术的应用，骨折复位的准确性明显提高，但对于眶颧颌骨折内固定材料的种类、型号及内固定方式的选择仍缺乏客观的量化指标，主要依靠术者的临床经验，常导致术后出现内固定装置移位、断裂等并发症。由于眶周力学环境对选择合适的个性化修复方式至关重要，本项目拟通过实验研究推导出眶周肌肉作用力与年龄、性别、肌肉横截面积、肌肉CT密度关系的校正公式，进而测算出修复术后生理状况下眶周肌肉对眶骨的作用力；在此基础上用有限元分析等技术构建眶颧颌骨折内固定数值模型，结合眼眶骨组织及目前临床常用眼眶骨折修复材料的生物力学特性，模拟分析修复材料应力、形变、移位情况，依据客观的量化指标选择最佳的修复材料和内固定方式，精准地指导临床治疗，以达到稳定的解剖和功能复位。

眶颧颌骨折是发病率较高的复合型眼眶骨折，严重影响患者的生理功能和外观；眶周力学环境对骨折修复重建影响巨大，若修复重建后骨折内固定与力学环境不相符，容易导致骨折愈合不佳、修复材料变形、移位甚至断裂等并发症，让患者遭受更多痛苦的同时增加了经济负担。本研究通过总结既往对眶周力量的测算，应用公式计算得到修复术后生理状况下眶周肌肉对眶骨的作用力，模拟了眶周的力学环境。在此基础上结合眼眶骨组织及目前临床常用眼眶骨折修复材料的生物力学特性，建立了眶颧颌骨折不同内固定方式和材料修复的有限元模型并分析骨折断端、修复材料的应力及位移，实现了术前对眶颧颌骨折不同内固定方式和材料的稳定性进行数字化分析评价，使术后效果可测、可视、可知。研究构建的眶颧颌骨折内固定有限元模型外观逼真、几何相似性好，模型通过了有效性验证，分析结果与实际术后效果对比进一步验证了有限元分析的准确性。本研究通过运用有限元生物力学分析方法提高了眶颧颌骨折手术的成功率、减少了术后并发症，为眶颧颌骨折的精准治疗提供了新的研究方法和客观的量化依据。