Differences of lumbosacral kinematics between degenerative and induced spondylolisthetic spine

Objective. To investigate the differences of lumbosacral kinematics between degenerative and induced spondylolisthetic subjects. Design. Translations and angulations of spondylolisthetic spine from L1–L2 to L5–S1 were documented by taking X-ray films at flexion, standing and extension positions. Background. The unstable mechanism of spondylolisthesis leads to lower back pain. It is important to determine the kinematics and the process of spondylolisthesis. Methods. Nineteen subjects with spondylolisthesis participated in this research, seven subjects with diagnosis of degenerative and 12 with induced spondylolisthesis, were taken lateral radiographs at three positions including flexion, standing and extension. Results. The differences of angulation among three positions (flexion, standing, and extension) at different levels were statistically significant (P<0.05) in both spondylolisthetic groups. The differences of translation among three different positions in induced spondylolisthetic group had a statistical significance (P<0.05) except at the level of L5–S1 (P>0.05). Conclusions. Segmental total translation and angulation at each level of induced spondylolisthetic spine were greater than those of degenerative spondylolisthetic spine except L5–S1 level, which illustrated the evolution of spondylolisthesis from unstable to less unstable.