Pei Xuan, Huang Jincheng, Fang Zhixun, Qian Shenglong, Zhou Wei, Wang Guodong, Lei Jianyin, Liu Ximing
Department of Orthopedics, General Hospital of Central Theater Command of PLA, Wuhan, 430070, Hubei Province, China.
University Center of Orthopaedic, Trauma and Plastic Surgery, University Hospital Carl Gustav Carus at Technische Universität Dresden, 01307, Dresden, Germany.
Sci Rep. 2025 May 14;15(1):16765. doi: 10.1038/s41598-025-00156-6.
Plate fixation is a classic method for treating day II crescent fracture dislocation of the pelvic (CFDP). However, due to the advantages of minimally invasive techniques and reduced complications associated with internal fixation percutaneous cannulated screws have emerged as a promising alternative for treating Day II CFDP. In this study, we propose using an SAI screw combined with an LC-2 screw (SAI + LC-2) for the treatment of Day II CFDP. The aim of this study was to compare its biomechanical stability with that of two conventional fixation methods using finite element analysis (FEA). A finite element (FE) model of pelvic was developed and validated. Three fixation methods were applied: S sacroiliac (SI) screws combined with LC-2 screw (S + LC-2), S and S SI screws combined with LC-2 screw (S + S + LC-2), and SAI + LC-2. A 500 N load was applied, and the displacement of the crescent fracture fragments, the stress distribution of the implants, the displacement of the SI joint, and the maximum stress on the bone surrounding the screws were analyzed across the three FE models. After loading 500 N stress, the maximum displacement of the crescent fracture fragment and the maximum stress of bone around the implant in the SAI + LC-2 group were the smallest in three groups. The displacement of SI joint in SAI + LC-2 group was less than that in S + LC-2 and S + S + LC-2 (P < 0.001). The maximum stress of implants in each group is smaller than the yield stress of titanium. The maximum stress of the bone around the screws at SI joint in all models lower than the yield strength of cortical bone. The maximum stress of the bone around LC-2 screws in all models lower than the yield strength of cancellous bone. The SAI + LC-2 group can achieve reliable stability of the SI joint, and the stress on the bone around the screw could be reduced. The SAI + LC-2 group has good biomechanical stability and can be considered as a new implant to treat Day II CFDP.
钢板固定是治疗骨盆Ⅱ型新月形骨折脱位（CFDP）的经典方法。然而，由于微创技术的优势以及与内固定相关的并发症减少，经皮空心螺钉已成为治疗Ⅱ型CFDP的一种有前景的替代方法。在本研究中，我们提出使用骶髂关节前路（SAI）螺钉联合LC-2螺钉（SAI + LC-2）治疗Ⅱ型CFDP。本研究的目的是通过有限元分析（FEA）比较其与两种传统固定方法的生物力学稳定性。建立并验证了骨盆的有限元（FE）模型。应用了三种固定方法：骶髂（SI）螺钉联合LC-2螺钉（S + LC-2）、双侧SI螺钉联合LC-2螺钉（S + S + LC-2）以及SAI + LC-2。施加500 N的载荷，并在三个有限元模型中分析新月形骨折碎片的位移、植入物的应力分布、骶髂关节的位移以及螺钉周围骨的最大应力。施加500 N应力后，SAI + LC-2组中新月形骨折碎片的最大位移和植入物周围骨的最大应力在三组中最小。SAI + LC-2组骶髂关节的位移小于S + LC-2组和S + S + LC-2组（P < 0.001）。每组植入物的最大应力均小于钛的屈服应力。所有模型中骶髂关节处螺钉周围骨的最大应力均低于皮质骨的屈服强度。所有模型中LC-2螺钉周围骨的最大应力均低于松质骨的屈服强度。SAI + LC-2组可实现骶髂关节可靠的稳定性，并可降低螺钉周围骨的应力。SAI + LC-2组具有良好的生物力学稳定性，可被视为治疗Ⅱ型CFDP的一种新型植入物。
