The effect of sagittal alignment on adjacent joint mobility after lumbar instrumentation––a biomechanical study of lumbar vertebrae in a porcine model

Object The porcine spine is widely used as an alternative to the human spine for both in vivo and in vitro spinal biomechanical studies because of the limited availability and high cost of human specimens. The aim of this study was to develop a reproducible in vitro osteoporotic vertebral model for spinal implant investigations. Methods Four mature domestic porcine lumbar spines (L1–5) were obtained. An in vitro decalcification method was used to decrease the mineral content of the porcine vertebrae, with Ca-chelating agents (0.5 M EDTA solution, pH 7.4) that altered the bone mineral density (BMD). Lumbar-spine area BMD was evaluated using dual-energy x-ray absorptiometry; spine volumetric BMD and spine geometry were assessed by central quantitative CT scanning to monitor the time it took the decalcification process to induce the WHO-defined standard of osteoporosis. Micro–computed topography provided information on the 3D microarchitecture of the lumbar vertebrae before and after decalcification with EDTA. Hematoxylin and eosin staining of lumbar vertebrae was performed. Both the control (5 specimens) and osteoporotic vertebrae (5 specimens) were biomechanically tested to measure compressive strength. Results The differences in area BMD measurements before and after the demineralizing processes were statistically significant (p < 0.001). The results of the compression test before and after the demineralizing processes were also statistically significant (p < 0.001). Conclusions The data imply that the acid demineralizing process may be useful for producing a vertebra that has some biomechanical properties that are consistent with osteoporosis in humans.

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Mechanical comparison of biodegradable femoral fixation devices for hamstring tendon graft – A biomechanical study in a porcine model

Clinical Biomechanics ◽

10.1016/j.clinbiomech.2009.02.003 ◽

2009 ◽

Vol 24 (5) ◽

pp. 435-440 ◽

Cited By ~ 11

Author(s):

Jia-Lin Wu ◽

Tsu-Te Yeh ◽

Hsain-Chung Shen ◽

Cheng-Kung Cheng ◽

Chian-Her Lee

Keyword(s):

Porcine Model ◽

Hamstring Tendon ◽

Tendon Graft ◽

Biomechanical Study ◽

Hamstring Tendon Graft ◽

Femoral Fixation ◽

Fixation Devices

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Application of a Novel Attachable Magnetic Nerve Stimulating Probe in Intraoperative Lumbar Pedicle Screw Placement: A Porcine Model Study

Applied Sciences ◽

10.3390/app11177801 ◽

2021 ◽

Vol 11 (17) ◽

pp. 7801

Author(s):

Tae Sik Goh ◽

Sung-Chan Shin ◽

Hyun-Keun Kwon ◽

Eui-Suk Sung ◽

Se Bin Jun ◽

...

Keyword(s):

Pedicle Screw ◽

Porcine Model ◽

Lumbar Vertebrae ◽

Pedicle Screws ◽

Screw Placement ◽

Lumbar Spine Surgery ◽

Pedicle Screw Placement ◽

Significant Difference ◽

Screw Malpositioning ◽

Lumbar Pedicle

Pedicle screw instrumentation is a fundamental technique in lumbar spine surgery. However, several complications could occur when placing a pedicle screw, the most serious being damage to the neural structures. We developed an attachable magnetic nerve stimulating probe used for triggered electromyography (t-EMG) to avoid these. This study aimed to investigate the efficacy of this probe for intraoperative neuromonitoring (ION) during lumbar pedicle screw placement in a porcine model. Forty pedicle screws were inserted bilaterally into the pedicles of the fourth and fifth lumbar vertebrae of five pigs; 20 were inserted typically into the pedicle without nerve damage (Group A), and the other 20 were inserted through the broken medial wall of the pedicle to permit contact with the neural structures (Group B). We measured the triggered threshold for pedicle screw placement through the conventional nerve probe and our newly developed magnetic probe. There was no significant difference in the triggered threshold between the two instruments (p = 0.828). Our newly developed magnetic stimulating probe can be attached to a screwdriver, thus preventing real-time screw malpositioning and making it practical and equally safe. This probe could become indispensable in revision spine surgeries with severe adhesions or endoscopic spine surgeries.

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Improvement of primary stability in ACL reconstruction by mesh augmentation of an established method of free tendon graft fixation. A biomechanical study on a porcine model

The Knee ◽

10.1016/j.knee.2012.09.015 ◽

2013 ◽

Vol 20 (2) ◽

pp. 79-84 ◽

Cited By ~ 6

Author(s):

Nadine von der Heide ◽

Lukas Ebneter ◽

Henrik Behrend ◽

Gordian Stutz ◽

Markus S. Kuster

Keyword(s):

Acl Reconstruction ◽

Porcine Model ◽

Primary Stability ◽

Tendon Graft ◽

Biomechanical Study ◽

Graft Fixation ◽

Established Method ◽

Mesh Augmentation

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Biomechanical study on the effect of five different lumbar reconstruction techniques on adjacent-level intradiscal pressure and lamina strain

Journal of Neurosurgery Spine ◽

10.3171/spi.2006.5.2.150 ◽

2006 ◽

Vol 5 (2) ◽

pp. 150-155 ◽

Cited By ~ 51

Author(s):

Hideki Sudo ◽

Itaru Oda ◽

Kuniyoshi Abumi ◽

Manabu Ito ◽

Yoshihisa Kotani ◽

...

Keyword(s):

Interbody Fusion ◽

Sagittal Alignment ◽

Biomechanical Study ◽

Intradiscal Pressure ◽

Adjacent Segment ◽

Initial Stiffness ◽

Flexion Extension ◽

Fusion Methods ◽

Local Kyphosis ◽

The One

Object The objectives of this study were to compare the biomechanical effects of five lumbar reconstruction models on the adjacent segment and to analyze the effects of three factors: construct stiffness, sagittal alignment, and the number of fused segments. Methods Nondestructive flexion–extension tests were performed by applying pure moments to 10 calf spinal (L3–S1) specimens. One-segment (L5–6) or two-segment (L5–S1) posterior fusion methods were simulated: 1) one-segment posterolateral fusion (PLF); 2) one-segment PLF with interbody fusion cages (one-segment PLIF/PLF); 3) two-segment PLF; 4) two-segment PLIF/PLF; and 5) two-segment PLF in kyphosis (two-segment kyphotic PLF). The range of motion (ROM) of the reconstructed segments, intradiscal pressure (IDP), and lamina strain in the upper (L4–5) adjacent segment were analyzed. The ROM was significantly decreased in the PLIF/PLF models compared with that in the PLF alone models after both the one- and two-segment fusions. If the number of fused segments was increased, the pressure and strains were also increased in specimens subjected to the PLIF/PLF procedure, more so than the PLF-alone procedure. In the one-segment PLIF/PLF model the authors observed a reduced IDP and lamina strain compared with those in the kyphotic two-segment PLF model despite the latter’s higher levels of initial stiffness. Conclusions If the number of fused levels can be reduced by using PLIF to correct local kyphosis, then this procedure may be valuable for reducing adjacent-segment degenerative changes.

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