Fig. 2From: Effect of Percutaneous Kyphoplasty on the progression of intervertebral disc degeneration: a retrospective cohort studyAn image reference panel showing the increasing severity of disc degeneration. The pertinent features of each grade are described in Table 1. Three images reflect the inherent variability across each grade. This figure is reproduced from Griffith, J. F. et al.21Back to article page