Fig. 1From: Predictors of accurate intrapedicular screw placement in single-level lumbar (L4-5) fusion: robot-assisted pedicle screw, traditional pedicle screw, and cortical bone trajectory screw insertionGrades of intrapedicular accuracy and facet joint violation: A grade A, B grade B, C grade C, D grade D, and E grade E; F Grade 0, G Grade 1, H Grade 2, and I Grade 3Back to article page