Animal model for disk displacement.

This paper describes the soft-tissue changes associated with surgically created, nonreducing disk displacements in the New Zealand white rabbit. Four rabbits, one control and three experimental, were used. The disk of the control animal had thick posterior and anterior bands separated by a thinner intermediate zone. The disk in the one animal sacrificed immediately after surgical disk displacement was buckled downward at the intermediate zone, with the posterior band lying inferior to the anterior band. The disks in the two animals sacrificed 2 months after surgical disk displacement were grossly deformed and clearly had abnormal internal architecture. Tissue reactions seem to be similar to those observed in human disk displacement specimens, namely disk remodeling and degenerative joint disease. This animal model will aid in the understanding of the progression of this disorder.