Question: what is a grade 1 spondylolisthesis?
Answer: One commonly used description grades spondylolisthesis, with grade 1 being least advanced, and grade 5 being most advanced. The spondylolisthesis is graded by measuring how much of a vertebral body has slipped forward over the body beneath it. Grade 1. 25% of vertebral body has slipped forward. Grade 2.