内侧柱缺失型肱骨近端骨折不同固定方式的有限元分析

文题释义： 肱骨近端内侧柱：肱骨近端内侧柱为肱骨头内下方的一段连续性骨皮质，主要起支撑肱骨头防止其内翻的作用。其主要包括后内侧干骺端的完整和对合及内侧铰链(骨膜)的完整性，锁定钢板固定稳定性的2个重要因素是骨密度低和缺乏内侧支撑。 肱骨内侧柱缺失型有限元模型：参照既往相关研究方法，在肱骨外科颈处模拟宽度为5 mm的骨质缺损，建立了可靠、有效的肱骨近端内侧柱缺失型有限元模型。对皮质骨、松质骨及髓腔分别赋予材料参数，并分别定义为均一、各向同性材料，忽略周围韧带及肌肉对骨折稳定性的影响。 背景：肱骨近端内侧柱缺失型骨折为内固定术后并发症较高的一种骨折类型，肱骨近端锁定钢板在肱骨近端骨折中应用广泛，然而单独应用肱骨近端锁定钢板与肱骨近端锁定钢板联合腓骨支撑治疗肱骨近端内侧柱缺失型骨折的生物力学稳定性尚不明确。目的：采用有限元分析方法，探讨单独应用肱骨近端锁定钢板与肱骨近端锁定钢板联合腓骨髓内支撑对内侧柱缺失型肱骨近端骨折内固定模型生物力学稳定性的影响，并比较肱骨距螺钉在2种不同固定方式下对内侧柱支撑的差异性。 方法：获取骨质疏松肱骨近端CT数据，按照肱骨解剖颈下5 mm截骨，建立肱骨近端内侧柱缺失型骨折模型，并分为A、B组。A组为肱骨近端锁定钢板组，其中A1组置入钢板近端全部螺钉，A2组为E钉空缺，A3组为D钉空缺；B组为肱骨近端锁定钢板联合腓骨髓内支撑组，其中B1置入钢板近端全部螺钉，B2组为E钉空缺，B3为D钉空缺。然后采用三维有限元法分析间接暴力状态下不同分组模型的生物力学稳定性。 结果与结论：①在结构稳定性方面，B组明显优于A组，A组中A1、A3组结构稳定性相当，且优于A2组；B组中B1、B2组结构稳定性相当且优于B3组；②对于内侧柱缺失型肱骨近端骨折，肱骨近端锁定钢板联合腓骨髓内支撑的力学稳定性优于单独应用肱骨近端锁定钢板；当联合腓骨支撑时，置入钢板近端全部螺钉效果最优，其中 D钉对肱骨近端内侧柱的支撑具有重要稳定作用。 ORCID: 0000-0002-5127-7857(刘炎) 中国组织工程研究杂志出版内容重点：人工关节；骨植入物；脊柱；骨折；内固定；数字化骨科；组织工程

Finite element analysis of different fixation methods for poor medial column support proximal humeral fracture

BACKGROUND:The medial column fracture of the proximal humeral fracture is a type of fracture with high postoperative complications after internal fixation.Proximal humeral internal locking system is widely used in the proximal humeral fracture.The biomechanical stability of two different internal fixation models for the treatment of the poor medial column support proximal humeral fractures with proximal humeral internal locking system and proximal humeral internal locking system with fibular allograft augmentation is still unclear.OBJECTIVE:To investigate the biomechanical stability of the proximal humeral internal locking system and proximal humeral internal locking system with fibular allograft augmentation in the poor medial column support proximal humeral fracture with finite element analysis,and to compare the difference in fixation modes in humeral calcar supporting screws under different fixing methods.METHODS:The proximal CT data of osteoporosis were obtained.According to the 5-mm osteotomy of the humerus,the posterior medial column of the humerus was established and divided into two groups.Group A was the proximal humeral internal locking system plate group,in which the A1 group was placed in the proximal end of the plate,the A2 group was the E screw missing,the A3 group was the D screw missing;the B group received the proximal humeral internal locking system plate combined with fibular allograft augmentation,and all screws was placed in the proximal end of the plate in the B1 group.In the B2 group,E screw was missing;in the B3 group,D screw was missing.The three-dimensional finite element method was used to analyze the biomechanical stability of different groups of models under indirect violence.RESULTS AND CONCLUSION:(1) In terms of structural stability,B group was significantly better than A group.The structural stability of A1 group and A3 group of A group was comparable and better than that in A2 group.In B group,the structural stability of B1 group and B2 group was comparable and superior to B3 group.(2) For the poor medial column support proximal humeral fracture,the mechanical stability of the proximal humeral internal locking system plate combined with fibular allograft augmentation was better than that of the proximal humeral intermal locking system plate alone.When the fibular support was combined,the screw placement in the proximal end of the plate is optimal,and D screw has an important stabilizing effect on the support of the poor medial column support proximal humeral fracture.