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Figure 4

A repeat radiograph taken nine months later demonstrates significant improvement in the majority of the spinal deformity. The C7 plumb line (red line) is drawn caudally from the C7 vertebra's center. The line should be parallel to or within 5 mm of S1's superior-posterior endplate. In a well-aligned subject, the line of COG (yellow line) has improved in the sagittal plane.