Fig. 1From: Comparison of unilateral and bilateral polymethylmethacrylate-augmented cannulated pedicle screw fixation for the management of lumbar spondylolisthesis with osteoporosisMeasurement methods for intervertebral disk height (a, H1/2 + H2/2), Taillard index (b, L-x2/L-x1), vertebral movement (c, Dextension-Dflexion and αextension-αflexion), and screw displacement values (d)Back to article page