In vivo model for intervertebral disc prolapse

An animal model for disc prolapse was developed and used to study the mechanical and morphological properties of the prolapsed and adjacent discs. Using routine surgical techniques, the anterior aspect of the cervical spine in three goats was exposed. Two different degrees of injury were created at adjacent levels by using nucleotomes of different diameters. After a 16-week period, the injured discs and the adjacent discs were retrieved and stored at -80°C. In vivo mechanical behavior was studied using range of motion (ROM). In particular, the in vivo morphological behavior was determined by disc height (DH) and routine histology. For the histological evaluations, control discs were obtained from six healthy animals. No statistically significant differences were observed in the ROM or the DH between preoperative and postoperative measurements. Further, the results compared favorably with the histology of human disc prolapse.