The incidence of cervical and lumbar fusion surgery has increased in the past twenty years, and during follow-up some of these patients develop changes at the adjacent segment. Recognizing that adjacent segment degeneration and disease may occur in the future does not alter the rating for a cervical or lumbar fusion at the time the patient's condition is determined to be at maximum medical improvement (MMI). The term adjacent segment degeneration refers to the presence of radiographic findings of degenerative disc disease, including disc space narrowing, instability, and so on at the motion segment above or below a cervical or lumbar fusion. Adjacent segment disease refers to the development of new clinical symptoms that correspond to these changes on imaging. The biomechanics of adjacent segment degeneration have been studied, and, although the exact mechanism is uncertain, genetics may play a role. Findings associated with adjacent segment degeneration include degeneration of the facet joints with hypertrophy and thickening of the ligamentum flavum, disc space collapse, and translation—but the clinical significance of these radiographic degenerative changes remains unclear, particularly in light of the known presence of abnormal findings in asymptomatic patients. Evaluators should not rate an individual in anticipation of the development of changes at the level above a fusion, although such a development is a recognized possibility.
Deyo R, Mirza S. Trends and variations in the use of spine surgery. Clin Orthop Relat Res. 2006;443:139-146.
Boden SD, Davis DO, Dina TS, Patronas NJ, Wiesel SW. Abnormal magnetic-resonance scans of the lumbar spine in asymptomatic subjects. A prospective investigation. J Bone Joint Surg Am. 1990;72(3):403-408.
Hilibrand AS, Robbins M. Adjacent segment degeneration and adjacent segment disease: the consequences of spinal fusion. Spine J. 2004;4(6):S190-S194.
Levin D, Hale J, Bendo J. Adjacent segment degeneration following spinal fusion for degenerative disc disease. Bulletin of NYU Hospital for Joint Diseases. 2007.
Park, P, Garton HJ, Gala V, Joff J, McGillicuddy JE. Adjacent segment disease after lumbar or lumbosacral fusion: review of the literature. Spine. 2004;29(17):1938-1944.
Battie M, Videman T, Kaprio J, et al. The twin spine study: contributions to a changing view of disc degeneration. Spine J. 2009;9(1):47-59.
Hilibrand AS, Carlson GD, Palumbo MA, et al. Radiculopathy and myelopathy at segments adjacent to the site of a previous anterior cervical arthrodesis. J Bone Joint Surg Am. 1999;81A(4):519-528.
Cheh G, Bridwell K, Lenke L, et al. Adjacent segment disease following lumbar/thoracolumbar fusion with pedical crew instrumentation: a minimum 5-year follow-up. Spine. 2007;32(20):2253-2257.
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