The immediate effect of repeated loading on the compressive strength of young porcine lumbar spine
| Autor: | Olof Thoreson, Mikael Hellström, Leif Swärd, Sten Holm, Adad Baranto, Lars Ekström |
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| Rok vydání: | 2009 |
| Předmět: |
Male
medicine.medical_specialty Radiography medicine.medical_treatment Sus scrofa In Vitro Techniques medicine.disease_cause Weight-bearing Weight-Bearing medicine Animals Orthopedics and Sports Medicine Intervertebral Disc Reduction (orthopedic surgery) Lumbar Vertebrae medicine.diagnostic_test business.industry Stiffness Magnetic resonance imaging Intervertebral disc Compression (physics) Magnetic Resonance Imaging Biomechanical Phenomena Surgery medicine.anatomical_structure Orthopedic surgery Spinal Fractures Stress Mechanical medicine.symptom Tomography X-Ray Computed business Biomedical engineering |
| Zdroj: | Knee Surgery, Sports Traumatology, Arthroscopy. 18:694-701 |
| ISSN: | 1433-7347 0942-2056 |
| DOI: | 10.1007/s00167-009-1001-z |
| Popis: | The human spine is exposed to repeated loading during daily activities and more extremely during sports. Despite this, there remains a lack of knowledge regarding the immediate effects on the spine due to this mode of loading. Age-specific spinal injury patterns has been demonstrated and this implies differences in reaction to load mode and load history The purpose of the present study was to investigate the impact of cyclic pre-loading on the biomechanical properties and fracture patterns of the adolescent spine in an experimental model. Eight functional spinal units from four young porcine spines were harvested. The functional spinal units were cyclic loaded with 20,000 cycles and then axially compressed to failure. The compression load at failure, ultimate stress and viscoelastic parameters were calculated. The functional spinal units were examined with plain radiography, computer tomography and MRI before and after the loading, and finally macroscopically and histologically. The median compression load at failure in this study was 8.3 kN (range 5.6-8.7 kN). The median deformation for all cases was 2.24 mm (range 2.30-2.7 mm) and stiffness was 3.45 N/mm (range 3.5-4.5 N/mm). A fracture was seen on radiograph in one case, on CT and macroscopically in seven, and on MRI and histologically in all eight cases. The cyclic loaded functional spinal units in the present study were not more sensitive to axial compression than non-cyclic loaded functional spinal units from young porcine. The endplate and the growth zone were the weakest part in the cyclic loaded functional spinal units. Disc signal reduction and disc height reduction was found on MRI. The E-modulus value found in this study was of the same order of magnitude as found by others using a porcine animal model. |
| Databáze: | OpenAIRE |
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