Grades of Anterolisthesis: Understanding Severity and its …

Grade 1 Anterolisthesis Grade 1 anterolisthesis is the mildest form of the condition, where the affected vertebra has slipped forward by less than 25% of its width relative to the adjacent vertebra. This grade often remains asymptomatic and may only be incidentally detected during imaging studies conducted for other purposes.

 https://www.spineinfo.com/conditions/spondylolisthesis/anterolisthesis/grades-of-anterolisthesis-understanding-severity-and-its-impact-on-your-health/