خواص مطلوب دیسک در مدلهای عددی و تاثیر آن بر رفتار بیومکانیکی ستون فقرات کمری

نوع مقاله : مقاله پژوهشی

نویسندگان

1 مهندسی مکانیک، دانشگه تهران، تهران، ایران

2 مهندسی مکانیک، دانشگاه تهران، تهران، ایران

3 مهندسی پزشکی، دانشگاه آزاد اسلامی واحد علوم و تحقیقات، تهران، ایران

4 جراح ستون فقرات، دانشگاه علوم پزشکی تهران، تهران، ایران

چکیده

در این پژوهش، مدل سازی المان محدود غیرخطی جهت بررسی پارامتری تاثیر خواص دیسک بر رفتار بیومکانیکی ستون فقرات کمری ارائه شده است. اجزاء این مدل شامل مهره )استخوان قشری و استخوان اسفنجی(، دیسک )هسته، آنالئوس فیبرسوس و فیبرهای کالژن(، صفحات انتهایی و رباط میباشد. پس از اعمال بارگذاری و شرایط مرزی، تحلیل مدل در نرمافزار آباکوس انجام می شود. همچنین آزمایشات تجربی پیشین در زمینه ستون فقرات حاکی از آن است که این عضو رفتار مکانیکی غیر خطی دارد؛ بنابراین برای دستیابی به این رفتار غیر خطی در مدل حاضر، رباط ها و فیبرهای آنالئوس به صورت فنر غیرخطی مدل سازی شده اند. نتایج بدست آمده از مدل حاضر که شامل فشار میان دیسکی و چرخش میان مهرهای است، با داده های آزمایشات تجربی و مطالعات عددی پیشین مقایسه شده است. بررسی نتایج این پژوهش نشان می دهد که با افزایش ضرایب ماده هایپراالستیک تشکیل دهنده دیسک، میزان چرخش میان مهرهای در هر حالت بارگذاری کاهش می یابد. بنایراین با تغییر خواص دیسک در ساخت دیسکهای مصنوعی میتوان محدوده حرکتی ستون فقرات بیماران مختلف را تغییر داد.

کلیدواژه‌ها

موضوعات


عنوان مقاله [English]

Desired Properties of Disc in Numerical Models and Its Influence on Biomechanical Behavior of Lumbar Spine

نویسندگان [English]

  • ali orang 1
  • Mojtaba Haghighi-Yazdi 2
  • Sadegh Naserkhaki 3
  • Saeed Reza Mehrpour 4
1 Master of Science, Mechanical Engineering Department , University of Tehran, Tehran, Iran
2 Assistant Professor,Mechanical Engineering Department, University of Tehran, Tehran, Iran
3 Assistant Professor, Biomedical Engineering Department, Islamic Azad University, Tehran, Iran
4 Associate Professor, Tehran University of Medical Sciences, Tehran, Iran
چکیده [English]

In this paper, nonlinear finite element modeling has been presented to conduct a parametric study of disc properties on biomechanical behavior of lumbar spine. This model includes vertebrae (cancellous bone and cortical bone), disc (nucleus, annulus fibrosus, and collagen fibers), end plates, and ligaments. 3 dimensions geometry was reconstructed from computed tomography scans of lumber spine. After applying loads (compression, moment and their combinations) and boundary conditions (fixed L5) to the model, finite element analysis was conducted. Experimental tests available in literature indicated that lumbar spine shows a nonlinear mechanical behavior; hence, to consider this nonlinear behavior in this work, ligaments and annulus fibers have been modeled as nonlinear springs. The obtained results of the current study, which include intradiscal pressure and intervertebral rotation, have been compared with previous in-vitro as well as numerical data. The results of this work showed that stiffening the disc leads to decreased intervertebral rotation in different anatomical planes and the intradiscal pressure.

کلیدواژه‌ها [English]

  • Lumbar spine
  • Finite element model
  • Intervertebral rotation
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