Wang Xiong, Zhang Zhi, Zi Shuming, Wei Wenqiang, Cheng Biao, Cao Liehu
Department of Sports Medicine, Tongji Hospital, School of Medicine, Tongji University, Shanghai, 200065, China.
Department of Orthopedics, Shanghai Baoshan Luodian Hospital, Baoshan District, Shanghai, 201908, China.
Injury. 2025 Aug;56(8):112568. doi: 10.1016/j.injury.2025.112568. Epub 2025 Jun 27.
Displaced tibial avulsion fractures of the posterior cruciate ligament (PCL) significantly compromise knee stability; however, existing clinical data regarding treatment and prognosis are limited. There exists a paucity of biomechanical research concerning various surgical methods for tibial avulsion fractures of the PCL, and optimal management remains controversial. Therefore, the objective of this study was to investigate the biomechanical stability of displaced tibial avulsion fracture using suture bridge fixation, screw fixation, and TightRope fixation at varying flexion angles.
Finite element analysis was employed to evaluate the biomechanical stability of three surgical approaches. A type III PCL tibial avulsion fracture model was established, followed by the assembly of models for suture bridge fixation, screw fixation, and TightRope fixation. Varying angles of knee flexion were simulated, and the stress distribution on the implant, the PCL, and the bone fragment, as well as the displacement of the fragment, were assessed.
The findings indicated that the peak stress distribution on the implant for screw fixation was the highest, occurring near the midsection and tail of the implant, followed by TightRope fixation, which occurred near both ends of the fixation. In contrast, suture bridge fixation exhibited the lowest stress, occurring near the junction between the anchor and the suture. The stress distribution of the PCL in screw and TightRope fixation was slightly higher than that observed with suture bridge fixation. This stress was primarily concentrated in the upper portion and gradually increased, reaching a maximum at 120° The peak von Mises stress (VMS) on the bone fragment in the suture bridge fixation group was the highest, followed by the screw fixation group, and subsequently the TightRope fixation group. Furthermore, the displacement of the bone fragment was comparable among the three fixation methods across various angles of knee flexion.
The biomechanical properties of suture bridge fixation are superior to those of both TightRope and screw fixation. They are all alternative surgical treatment methods for displaced tibial avulsion fractures of the PCL. The ideal surgical approach should be selected based on the clinical context and a comprehensive evaluation.
后交叉韧带（PCL）胫骨撕脱骨折移位会严重损害膝关节稳定性；然而，关于治疗和预后的现有临床数据有限。关于PCL胫骨撕脱骨折的各种手术方法，生物力学研究较少，最佳治疗方案仍存在争议。因此，本研究的目的是探讨缝线桥固定、螺钉固定和TightRope固定在不同屈曲角度下对移位胫骨撕脱骨折的生物力学稳定性。
采用有限元分析评估三种手术方法的生物力学稳定性。建立III型PCL胫骨撕脱骨折模型，然后组装缝线桥固定、螺钉固定和TightRope固定的模型。模拟不同的膝关节屈曲角度，评估植入物、PCL和骨块上的应力分布以及骨块的位移。
结果表明，螺钉固定植入物上的峰值应力分布最高，出现在植入物中部和尾部附近，其次是TightRope固定，出现在固定两端附近。相比之下，缝线桥固定的应力最低，出现在锚钉与缝线的连接处附近。螺钉和TightRope固定中PCL的应力分布略高于缝线桥固定。该应力主要集中在上部并逐渐增加，在120°时达到最大值。缝线桥固定组骨块上的峰值冯·米塞斯应力（VMS）最高，其次是螺钉固定组，然后是TightRope固定组。此外，在不同膝关节屈曲角度下，三种固定方法的骨块位移相当。
缝线桥固定的生物力学性能优于TightRope固定和螺钉固定。它们都是PCL胫骨撕脱骨折移位的替代手术治疗方法。应根据临床情况和综合评估选择理想的手术方法。
