Anterolisthesis: The forward positioning of one spinal vertebra in relation to the adjacent vertebra beneath it. Anterolisthesis can be graded: Grade 1 is less than 25% slippage, grade 2 between 25%-50% slippage, grade 3 between 50%-75% slippage, and grade 4 greater than 75% slippage. Symptoms of anterolisthesis depend on the severity, location, and cause. The opposite of anterolisthesis is retrolisthesis or backward positioning of one vertebra in relation to the adjacent vertebra beneath it.
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References
Klippel, J.H., et al. Primer on the Rheumatic Diseases. New York: Springer, 2008.