Abstract
The purpose of this study was to observe the degeneration of the intervertebral discs in experimental models of unstable cervical spines. Seventeen Japan white rabbits (8-12 weeks old), on which cervical laminectomy (from C3-C6) had been performed, were the subjects. X-P and MRI were taken at regular intervals after surgery, and histological studies were done immediately after the rabbits were killed.
Instability of the intervertebral spaces observed in X-P appeared mostly in the lower cervical spine. At the level of C6-7, displacement of the vertebral body (more than 20%) was found in 70% of the cases two months after surgery. Degeneration and herniation of the discs, detected by MRI, were later confirmed by histological studies.
The next step will be to clarify the role of each posterior element of the cervical spine in preventing instability and degeneration of the intervertebral spaces.
