An investigation of the mechanism of adjacent segment disease in a porcine spine model

IF 1.4 3区医学 Q4 ENGINEERING, BIOMEDICAL

Clinical Biomechanics Pub Date : 2025-02-01 DOI:10.1016/j.clinbiomech.2025.106441

Noah Chow , Sabrina I. Sinopoli , Mitchel C. Whittal , Drew A. Bednar , Diane E. Gregory

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引用次数: 0

Abstract

Background

Fusion changes the biomechanics of the spine leading to the potential development of adjacent segment disease. Despite many studies on adjacent segment disease, it is largely unknown how spinal fixation affects the mechanical properties of the adjacent disc. The purpose of this study was to assess whether axial compression causes mechanical disruption to the annulus when the caudal spinal level is immobilized or injured.

Methods

Fifty-two porcine spines were assigned to one of four conditions: 1) control; 2) injured (18.5-gauge needle inserted into the nucleus of cervical 4/5); 3) immobilized (18-gauge steel wire wrapped around the transverse and spinous processes of cervical 4/5); and 4) injured+immobilized. Each specimen was then subjected to 0.5 Hz cyclic compression (300−1200N) for two hours. Post-compression, three annular samples were dissected from the cervical 3/4 disc (adjacent to immobilized and/or injured level) and mechanically tested. The same loading protocol and annular testing was also conducted in eight human cadaveric lumbar spines.

Findings

Immobilization and injury resulted in a reduction in adjacent disc lamellar strength including toe region stress (p < 0.001), initial failure stress (p = 0.03), and ultimate stress (p = 0.004), with immobilization having the greatest impact. Similar findings were observed in the human cadaver samples with reduced toe region strength in the injured+ immobilized samples compared to the control (p = 0.049).

Interpretation

The current study provides empirical evidence of decreased lamellar strength in the disc adjacent to an immobilized and/or injured level following prolonged cyclic axial loading, lending mechanistic insight into the development of adjacent segment disease.

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猪脊柱模型邻近节段疾病发生机制的研究。

背景：融合改变了脊柱的生物力学，导致相邻节段疾病的潜在发展。尽管有许多关于临近节段疾病的研究，但脊柱固定如何影响临近椎间盘的力学特性在很大程度上是未知的。本研究的目的是评估当尾椎水平固定或受伤时，轴向压缩是否会导致环的机械破坏。方法：将52根猪棘分为4组：1)对照组；2)损伤（18.5号针刺入颈核4/5）；3)固定（18号钢丝缠绕颈椎横突和棘突4/5）；4)受伤+固定。然后将每个试件进行0.5 Hz循环压缩（300-1200N）两小时。压缩后，从颈椎3/4椎间盘（靠近固定和/或损伤节段）剥离3个环状样本并进行力学测试。同样的加载方案和环形试验也在8个人体尸体腰椎中进行。研究结果：固定和损伤导致邻近椎间盘板层强度降低，包括趾部应力(p)。解释：目前的研究提供了经验证据，证明在长时间循环轴向载荷后，固定和/或损伤水平附近椎间盘板层强度降低，为邻近节段疾病的发生提供了机制上的见解。

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.