adjacent inferior vertebral body]. grade I: %; grade II: %; grade III: 51 %; grade IV: %; grade V (spondyloptosis): >% anterolisthesis. In grade I1anterolisthesis, there is mild slippage that is less than 25%. In grade 2 anterolisthesis, the slippage is more than 25% but less than. My CT report says Grade 2 anterolisthesis with severe right and severe left neural foraminal narrowing secondary to the listhesis and pseudo.