ABSTRACT
Throughout the twentieth century, orthopedic surgeons and neurosurgeons have developed techniques to eliminate motion or fuse vertebral bodies in order to eliminate the painful stimuli leading to spinal pain. During the 1980s there was a marked increase in the performance of spinal fusion procedures of both the cervical and the lumbar spine within the United States, for which data have been published (1). The results of fusion, in terms of both radiographic and clinical outcomes, are beyond the scope of this chapter. However, one important sequela of spinal fusion is the alteration in biomechanics caused by eliminating motion at one or more segments in the spinal column and the implications of this motion being accommodated elsewhere in the spinal column. The biomechanical, radiographic, and clinical implications of this ‘‘postarthrodesis adjacent segment degeneration’’ will be the topic of this chapter.
