Fig. 2From: Is lumbar facet joint tropism developmental or secondary to degeneration? An international, large-scale multicenter study by the AOSpine Asia Pacific Research Collaboration ConsortiumAxial MRI noting assessment of facet joint angulation. The images note patients with facet joint a) tropism and b) non-tropism. Asymmetry of the left and right facet joint angulations greater or equal to 8° angulation was defined as tropismBack to article page