Torsional fatigue of the lumbar intervertebral joints
| Autor: | K Nishiyama, Vijay K. Goel, Alf Dejong, Joseph A. Buckwalter, G Njus, Y K Liu |
|---|---|
| Rok vydání: | 1985 |
| Předmět: |
Adult
Male Lumbar Cadaver Joint capsule Medicine Torque Humans Orthopedics and Sports Medicine Composite material Intervertebral Disc Aged Lumbar Vertebrae business.industry Angular displacement Biomechanics Fatigue testing Torsion (mechanics) Anatomy Middle Aged Biomechanical Phenomena medicine.anatomical_structure Female Joints Neurology (clinical) Stress Mechanical business |
| Zdroj: | Spine. 10(10) |
| ISSN: | 0362-2436 |
| Popis: | The effect of cyclic torsional loads on the behavior of intact lumbar intervertebral joints was investigated. A total of 24 specimens, divided in two groups, were tested. In the first group, a specimen was subjected to a specified constant cyclic torque, and the resulting change in angular displacement with time was recorded. The specimens in the second group were subjected to a specified constant angular displacement and the resultant torque recorded. The results of the constant torque tests showed that fatigue failure was primarily a function of the averaged initial angular displacement and secondarily of the applied torque. The critical threshold values appear to be an initial angular displacement of +/- 1.5 degrees. All specimens, displaying an averaged initial angular displacement of less than +/- 1.5 degrees, did not fail in fatigue, while the others did. However, the specimens with angular displacements of less than +/- 1.5 degrees had lower applied torques (11.3 and 22.6 Nm), while specimens with higher applied torques (33.9 and 45.2 Nm) all exceeded the +/- 1.5 degrees threshold and failed in fatigue. Failure locations occurred in such diverse regions as end-plates, facets, laminae, capsular ligaments, etc. All specimens exhibited a synovial fluid discharge from the apophyseal joint capsule sometime during testing. Post-test examinations of all the cartilage surfaces showed fibrillation, whether or not the intervertebral joint failed. |
| Databáze: | OpenAIRE |
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