OPLL (ossification of the posterior longitudinal ligament) Definition: Abnormal proliferation and ossification of the posterior longitudinal ligament of the cervical spine, resulting in reduced spinal canal volume and spinal cord and nerve compression symptoms. Cervical spondylosis Treatment: If the symptoms are mild and there are no cone bundle signs, physical therapy, acupuncture, antispasmodic and pain relief are feasible, and attention should be paid to prevent neck trauma; if the symptoms are severe and cone bundle signs appear, vertebroplasty and decompression are performed.