Three-dimensional surface strain analyses of simulated defect and augmented spine segments: A biomechanical cadaveric study

Asghar Rezaei; Maryam Tilton; Hugo Giambini; Yong Li; Alexander Hooke; Alan L Miller Ii; Michael J Yaszemski; Lichun Lu

doi:10.1016/j.jmbbm.2021.104559

Three-dimensional surface strain analyses of simulated defect and augmented spine segments: A biomechanical cadaveric study

J Mech Behav Biomed Mater. 2021 Jul:119:104559. doi: 10.1016/j.jmbbm.2021.104559. Epub 2021 Apr 23.

Authors

Asghar Rezaei¹, Maryam Tilton¹, Hugo Giambini², Yong Li¹, Alexander Hooke³, Alan L Miller Ii³, Michael J Yaszemski¹, Lichun Lu⁴

Affiliations

¹ Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, MN, USA; Department of Orthopedic Surgery, Mayo Clinic, Rochester, MN, USA.
² Department of Biomedical Engineering and Chemical Engineering, University of Texas at San Antonio, San Antonio, TX, USA.
³ Department of Orthopedic Surgery, Mayo Clinic, Rochester, MN, USA.
⁴ Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, MN, USA; Department of Orthopedic Surgery, Mayo Clinic, Rochester, MN, USA. Electronic address: lu.lichun@mayo.edu.

Abstract

While several studies have investigated fracture outcomes of intact vertebrae, fracture properties in metastatically-involved and augmented vertebrae are still far from understood. Consequently, this study was aimed to use 3D digital image correlation (3D-DIC) method to investigate the failure properties of spine segments with simulated metastatic lesions, segments augmented with poly(propylene fumarate) (PPF), and compare the outcomes with intact spines. To this end, biomechanical experiments accompanied by 3D-DIC were performed on spine segments consisting of three vertebrae and two intervertebral discs (IVDs) at loading rates of 0.083 mm/s, mimicking a physiological loading condition, and 200 mm/s, mimicking an impact-type loading condition such as a fall or an accident. Full-field surface strain analysis indicated PPF augmentation reduces the superior/inferior strain when compared with the defect specimens; Presence of a defect in the middle vertebra resulted in shear band fracture pattern. Failure of the superior endplates was confirmed in several defect specimens as the superior IVDs were protruding out of defects. The augmenting PPF showed lower superior/inferior surface strain values at the fast speed as compared to the slow speed. The results of our study showed a significant increase in the fracture force from slow to fast speeds (p = 0.0246). The significance of the study was to determine the fracture properties of normal, pathological, and augmented spinal segments under physiologically-relevant loading conditions. Understanding failure properties associated with either defect (i.e., metastasis lesion) or augmented (i.e., post-treatment) spine segments could potentially provide new insights on the outcome prediction and treatment planning. Additionally, this study provides new knowledge on the effect of PPF augmentation in improving fracture properties, potentially decreasing the risk of fracture in osteoporotic and metastatic spines.

Keywords: Biomechanics of vertebral bodies; Fracture outcomes; Mechanical testing; Metastasis; Vertebral augmentation.

Publication types

Research Support, N.I.H., Extramural
Research Support, Non-U.S. Gov't

MeSH terms

Biomechanical Phenomena
Cadaver
Humans
Intervertebral Disc*
Lumbar Vertebrae
Spinal Fractures*
Spine

Abstract

Publication types

MeSH terms

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