Fig. 2. Diagrammatic explanation of the surface marking used for identifying the site of needle insertion; also depicted is the needle trajectory. 1: line in the midline along the spinous processes, 2: line along the intervertebral disc with C-arm in anteroposterior view, 3: line along the intervertebral disc with the C-arm in the lateral view, 4: line denoting center of the disc with C-arm in the lateral view, 5: a perpendicular from line 2 onto line 3 at a distance ‘d’ from the midline, 6: point of needle insertion for posterolateral approach of provocative discography, d: distance from skin surface to line ‘4’ as measure in lateral view of C-arm.
© Korean J Pain
