July 18, 2024

Ossification of posterior longitudinal ligaments (OPLL) is defined as a chronically progressive disease of ectopic endochondral and membranous ossification of the posterior longitudinal ligaments of unknown etiology


Multifactor condition.

COLA1, COLA2, and NPPS genes are associated with the origin of OPLL

Posterior longitudinal ligament

2 layered

  1. Superficial  ( Close contact with dura and bridges 3 or 4 layers)
  2. Deep ( Located posterior to the vertebral bodies and connects 2 adjacent vertebrae)

Incidence: 3% of the Japanese population (Japanese disease)

Mostly occurs in the cervical spine

OPLL can cause

  • Spinal stenosis and myelopathy (cord compression)
  • Ossified dura mater and fuse with PLL (dural ossification)

The average age of onset is 50 Years

The patient may present with axial neck and upper limb pain, sensory symptoms and muscle weakness in the arm, UMN injuries

Cervical spinal cord injury (SCI) can be induced by minor cervical trauma in the patient with ossification of posterior longitudinal ligaments


Diagnostic criteria are:


OPLL visible on lateral view Xray (CT can be useful for better assessment)


Cervical myelopathic symptoms, radicular symptoms, and cervical spine range of motion abnormality

Classification of OPLL

Divided into four types


Long lesion extending into several vertebrae


One or several separate lesions behind vertebrae bodies


The combination of continuous and segmental types


The lesion is mainly located posterior to the disc space

Classification of OPLL
Classification of OPLL

Imaging for OPLL

X-ray shows dense ossification along the back of vertebral bodies

CT Scan shows the double layered sign on the axial bone window, consisting of an anterior (ligamental) and posterior (dural) rim of hyperdense ossification

MRI: Look for the features of myelopathy

Treatment Options

Medical treatment is concerned with symptomatic relief

Options for medical management are

  • Analgesics
  • Anti-inflammatory
  • Anti-depressant
  • Anti-convulsant
  • Opioids

Gold Standard

Surgical Decompression is Indicated in severe and progressive disease.