Animal Models and Imaging of Intervertebral Disc Degeneration
Low back pain (LBP) is commonly associated with a progressive age-related degeneration of intervertebral discs (IVDs). The question of quadrupedal locomotion and the influence on IVD biomechanics frequently arises when looking for an animal model of DDD. With the exception of monkeys and bipedal mice and rats, all animal models of DDD are quadrupedal. Like humans, several animal species exhibit spontaneous degeneration. Mediterranean sand rats that develop extensive DDD associated with diabetes when fed with a standard laboratory diet have been thoroughly studied. Considering that evolution toward the erected posture could increase the mechanical stress applied to the lumbar spine, bipedal mice and rats have been created by forelimb clipping or amputation. The IVD degeneration induced by fusion has been studied in both rabbits and dogs. The goal of chemonucleolysis is to mimic the selective degradation of proteoglycans that occurs in disc degeneration. Human disc degeneration, as a complex multifactorial process, alters both the biochemical composition and architecture of IVD.