Which statement correctly describes the regional distribution of OPLL?

Which statement correctly describes the regional distribution of OPLL?

• A. Cervical Region 80 Percent, Thoracic 10 Percent, Lumbar 10 Percent
• B. Cervical 60 Percent, Thoracic 20 Percent, Lumbar 20 Percent
• C. Cervical 90 Percent, Thoracic 5 Percent, Lumbar 5 Percent
• D. Cervical 70 Percent, Thoracic 15 Percent, Lumbar 15 Percent

Answer: (A)

The main idea is that ossification of the posterior longitudinal ligament most often involves the cervical spine, with far fewer cases in the thoracic and lumbar regions. About four-fifths of OPLL lesions occur in the cervical region, with roughly one-tenth in the thoracic region and one-tenth in the lumbar region. This pattern reflects why cervical myelopathy is the most common clinical consequence of OPLL: the cervical canal is smaller and experiences more motion and dynamic loading, making ossified ligament there more likely to encroach on the spinal cord. The thoracic region is relatively stabilized by the rib cage and has less mobility, and the lumbar region tends to be less affected by PLL ossification overall. There is some variation between populations, but the cervical predominance (around 80%) is the best-supported description.

The main idea is that ossification of the posterior longitudinal ligament most often involves the cervical spine, with far fewer cases in the thoracic and lumbar regions. About four-fifths of OPLL lesions occur in the cervical region, with roughly one-tenth in the thoracic region and one-tenth in the lumbar region. This pattern reflects why cervical myelopathy is the most common clinical consequence of OPLL: the cervical canal is smaller and experiences more motion and dynamic loading, making ossified ligament there more likely to encroach on the spinal cord. The thoracic region is relatively stabilized by the rib cage and has less mobility, and the lumbar region tends to be less affected by PLL ossification overall. There is some variation between populations, but the cervical predominance (around 80%) is the best-supported description.