ABSTRACT
The movement toward motion-preserving technology, such as disc replacement and posterior dynamic stabilization, as an alternative to lumbar fusion has been driven by the recognition of the potential deleterious effects of adjacent segment degeneration (ASD) (1-5). Despite the continually expanding market of motion preservation devices, a clear understanding of the predisposing factors and the clinical significance of ASD in the lumbar spine is still lacking. It was the authors’ purpose in this Chapter to review the published literature from the past 25 years to gain a better understanding of the incidence and risk factors for ASD. Although previous studies have compiled lists of risk factors, it was this study’s goal to perform a meta-analysis of the data from the available literature to determine the incidences of ASD for various subgroups of patients. In particular, the authors were interested in the influence of controllable surgical factors, such as fusion method and the use of pedicle screws.
