Posterior Decompression and Fusion for Cervical OPLL: Indication and Technique

Abstract

Surgical indication of posterior decompression and fusion (PDF) for cervical OPLL in mainly based on K-line, which is defined as that which connects the midpoints of the spinal canal at C2 and C7 in a plain lateral radiogram of the cervical spine. We defined K-line (+) as cases where the peak of ossification foci does not exceed the K-line and K-line (-) as cases where the peak of ossification foci exceeds the K-line. Previous reports revealed that laminoplasty produces a poor outcome in K-line (-) OPLL. One of the surgical options is PDF. Generally, fixation from C2 to C7 or T1 is applied because the C2 pedicle screw is the most reliable anchor in the cervical spine, and the C7 and/or T1 pedicle screw can be inserted without risk of vertebral artery violation. A lateral mass screw is generally used as a mid-cervical fixation anchor. PDF surgery is an option for cervical OPLL. PDF might improve the clinical outcome of OPLL patients with K-line (-).