====== K-line negative ======

Although posterior decompressive surgery is widely used to treat patients with [[cervical myelopathy]] and multilevel [[ossification of the posterior longitudinal ligament]] (OPLL), a poor outcome is anticipated if the [[sagittal alignment]] is kyphotic (or [[K-line]] negative).

{{::k_line_negative.jpg?600|}}

Lateral radiograph showing the K-line (solid line) connecting the midpoints of the spinal canal at C2 and C7 (K-line [−]) (A). Lateral radiograph showing the ossification of the posterior longitudinal ligament not exceeding the K-line (K-line [+]) (B).