Lai Juntong, Tomlinson James, Breakwell Lee, Lacroix Damien
School of Mechanical, Aerospace and Civil Engineering, University of Sheffield, Sheffield, UK.
Insigneo Institute for Insilico Medicine, University of Sheffield, Sheffield, UK.
Proc Inst Mech Eng H. 2025 Jul;239(7):607-623. doi: 10.1177/09544119251348279. Epub 2025 Jul 7.
Spinal metastases can increase the risks of vertebral fracture due to bony destruction and instability in the spine. There are concerns that cross-links may impair adjuvant treatments, such as radiotherapy and proton beam therapy. The aim of this study was to assess the biomechanical effects of cross-link stabilisation for a growing tumour in order to provide recommendations on the use and placement of the cross-link. A finite element (FE) model of a fixation device was developed. The device was inserted virtually into a FE model of the lumbar spine (L1-S1) between L2 and L4. Tumour deposit of either 1.3%, 10.1%, 38.3%, 71.5% and 92.1% of the vertebral body was simulated. A 1000 N compressive, a 10° lateral bending and a 7.5 Nm torsional load were simulated on the top of L1. Results indicate that the stabilisation is capable of reducing the stress of the L3 lumbar spine under torsion with a growing tumour. However, compressive loading is concentrated in the L3 anterior vertebra when the tumour volume was greater than 10.1% of the vertebra volume. The cross-link stabilisation reduced the stress of the posterior body within the stabilised segments (L2-L4), especially under torsion. The position of the cross-link does affect the ability of stabilisation to reduce concentrated stress of both vertebrae and screws, which indicates that the position of the cross-link should be considered in clinical surgery to refine the stress concentration, spinal stability and structural stiffness, without compromising adjuvant treatments.
脊柱转移瘤可因骨质破坏和脊柱不稳定而增加椎体骨折的风险。有人担心连接棒可能会影响辅助治疗，如放疗和质子束治疗。本研究的目的是评估连接棒稳定化对生长性肿瘤的生物力学影响，以便就连接棒的使用和放置提供建议。建立了固定装置的有限元（FE）模型。将该装置虚拟插入腰椎（L1-S1）L2和L4之间的有限元模型中。模拟了占椎体1.3%、10.1%、38.3%、71.5%和92.1%的肿瘤沉积物。在L1顶部模拟了1000 N的压缩力、10°的侧弯和7.5 Nm的扭转力。结果表明，随着肿瘤生长，稳定化能够降低L3腰椎在扭转时的应力。然而，当肿瘤体积大于椎体体积的10.1%时，压缩载荷集中在L3椎体前部。连接棒稳定化降低了稳定节段（L2-L4）内椎体后部的应力，尤其是在扭转时。连接棒的位置确实会影响稳定化降低椎体和螺钉集中应力的能力，这表明在临床手术中应考虑连接棒的位置，以改善应力集中、脊柱稳定性和结构刚度，同时不影响辅助治疗。
