The goal of this study was to develop and validate a system for the telemetric measurement of in vivo compressive intervertebral loads in the sheep, and to measure these loads in a variety of activities. / A miniature load cell and radio transmitter were implanted in the L3--L4 space of the spine. A total of four sheep were operated on; one was sacrificed five days after surgery, due to failure of the transmitter, and another was sacrificed after failing to ambulate for two weeks after surgery. The other two animals (average mass 67 kg) were kept for five weeks, during which a range of activities were performed, including standing, lying prone, walking/trotting, and jumping. / Results for a range of activities were as follows: in walking at 1.5 m/s, average maximum and minimum loads were 461 N and 256 N, respectively; in walking at 2m/s, average maximum and minimum loads were 684 N and 303 N, respectively; in standing, loads averaged 161 N; and in lying prone, loads averaged 212 N. The highest loads were recorded in jumping, where the peak load was 1290 N. / The results of this study demonstrate for the first time, to our knowledge, the magnitude of in vivo axial loads in the sheep lumbar spine. These findings have implications for the evaluation of studies which employ the sheep model to test spinal implants. As treatment methods for disc degeneration progress from the spacer and fusion approach to more sophisticated prostheses and tissue engineered disc replacements which preserve segmental mobility, such data will become even more important to the design, animal testing, and evaluation of implants.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.30785 |
| Date | January 2000 |
| Creators | Hauerstock, David. |
| Contributors | Steffen, Thomas (advisor) |
| Publisher | McGill University |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Format | application/pdf |
| Coverage | Master of Engineering (Department of Biomedical Engineering.) |
| Rights | All items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated. |
| Relation | alephsysno: 001804654, proquestno: MQ70234, Theses scanned by UMI/ProQuest. |
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