Does spinopelvic alignment affect fixation stability in pelvic ring fractures?: A finite element study

IF 1.4 3区医学 Q4 ENGINEERING, BIOMEDICAL

Clinical Biomechanics Pub Date : 2025-07-16 DOI:10.1016/j.clinbiomech.2025.106622

Sudharshan Tripathi , Yogesh Kumaran , Sophia M. Soehnlen , Muzammil Mumtaz , Amey Kelkar , Daksh Jayaswal , Toshihiro Seki , Takashi Sakai , Carmen E. Quatman , Norihiro Nishida

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Abstract

Background

The pelvic ring plays a pivotal role in maintaining biomechanical stability during upright posture. While lumbopelvic fixation is effective for stabilizing unstable pelvic fractures, the influence of spinopelvic alignment, particularly sacral slope on fixation mechanics and stress on adjacent joints, has not been adequately investigated.

Methods

A finite element model of the lumbar spine, pelvis, and femur was used to simulate a pelvic ring fracture. Three spinopelvic configurations were analyzed (sacral slope = 20°, 26°, 32°), each stabilized with lumbopelvic fixation, with or without a cross connector. Biomechanical parameters including fracture displacement, lumbar intersegmental mobility, intervertebral disc stress, sacroiliac joint motion, and implant stress were evaluated under physiological loading.

Findings

A steeper sacral slope increased mobility at the L5 to S1 segment, nucleus pulposus stress, and stress at the sacroiliac joint, suggesting potential for degeneration and mechanical overload. Rod stress was also the highest in models with a steeper sacral slope. Models with a shallower sacral slope showed reduced rod and disc stress but greater pelvic tilt. Cross connectors reduced motion and stress in all configurations, especially under steep sacral slope conditions. Displacement at the sacral and pubic fractures was also greater with steep sacral slope. Fixation stability was optimal in the model with normal alignment and compromised in the steeper alignment.

Interpretation

To our knowledge, this is the first biomechanical study investigating how sacral slope influences the mechanical behavior of lumbopelvic fixation constructs in the setting of unstable pelvic ring fractures using finite element methods. Understanding the biomechanical effects of variations in spinopelvic parameters can aid in decision making for implant selection strategy as well as preoperative planning in high-risk patient populations. The finite element simulations suggest that higher sacral slopes may biomechanically reduce fixation stability, highlighting the potential importance of spinopelvic assessment in preoperative planning. Cross-connectors demonstrated mechanical benefits in this FE model and may be considered in high SS cases, pending further clinical validation.

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脊柱-骨盆对线是否影响骨盆环骨折的固定稳定性？一项有限元素研究

背景：骨盆环在保持直立姿势的生物力学稳定性方面起着关键作用。虽然腰骨盆固定对稳定不稳定骨盆骨折是有效的，但脊柱骨盆对线，特别是骶骨坡度对固定力学和相邻关节应力的影响尚未得到充分研究。方法采用腰椎、骨盆、股骨有限元模型模拟骨盆环骨折。分析了三种脊柱骨盆形态（骶骨坡度= 20°，26°，32°），每一种都用腰骨盆固定固定，有或没有交叉接头。生物力学参数包括骨折位移、腰椎节段间活动度、椎间盘应力、骶髂关节运动和植入物应力在生理负荷下进行评估。发现更陡的骶骨坡度增加了L5至S1节段的活动性、髓核应力和骶髂关节应力，提示退变和机械负荷的可能性。在骶部坡度较大的模型中，杆应力也最大。骶骨坡度较浅的模型显示棒和椎间盘应力减少，但骨盆倾斜较大。十字连接器减少了所有配置中的运动和应力，特别是在陡峭的骶骨斜坡条件下。骶骨和耻骨骨折的移位也随着骶骨坡度的增大而增大。正常对准模型的固定稳定性最佳，较陡对准模型的固定稳定性较差。据我们所知，这是第一个使用有限元方法研究骶骨坡度如何影响不稳定骨盆环骨折情况下腰骨盆固定装置力学行为的生物力学研究。了解脊柱骨盆参数变化的生物力学效应可以帮助高风险患者选择植入物策略和术前计划。有限元模拟表明，较高的骶骨坡度可能从生物力学角度降低固定稳定性，强调了术前计划中脊柱骨盆评估的潜在重要性。交叉连接器在FE模型中显示出力学上的益处，在高SS病例中可能会被考虑，有待进一步的临床验证。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Clinical Biomechanics 医学-工程：生物医学

CiteScore

3.30

自引率

5.60%

发文量

189

审稿时长

12.3 weeks

期刊介绍： Clinical Biomechanics is an international multidisciplinary journal of biomechanics with a focus on medical and clinical applications of new knowledge in the field. The science of biomechanics helps explain the causes of cell, tissue, organ and body system disorders, and supports clinicians in the diagnosis, prognosis and evaluation of treatment methods and technologies. Clinical Biomechanics aims to strengthen the links between laboratory and clinic by publishing cutting-edge biomechanics research which helps to explain the causes of injury and disease, and which provides evidence contributing to improved clinical management. A rigorous peer review system is employed and every attempt is made to process and publish top-quality papers promptly. Clinical Biomechanics explores all facets of body system, organ, tissue and cell biomechanics, with an emphasis on medical and clinical applications of the basic science aspects. The role of basic science is therefore recognized in a medical or clinical context. The readership of the journal closely reflects its multi-disciplinary contents, being a balance of scientists, engineers and clinicians. The contents are in the form of research papers, brief reports, review papers and correspondence, whilst special interest issues and supplements are published from time to time. Disciplines covered include biomechanics and mechanobiology at all scales, bioengineering and use of tissue engineering and biomaterials for clinical applications, biophysics, as well as biomechanical aspects of medical robotics, ergonomics, physical and occupational therapeutics and rehabilitation.