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Ligament Neck

Posterior Longitudinal Ligament — Ossified (OPLL)

ligamentum longitudinale posterius ossificans (OPLL)

Ossification of the posterior longitudinal ligament (OPLL) is a pathological condition most prevalent in East Asian populations (3% of Japanese adults) where the cervical PLL undergoes ectopic ossification, progressively narrowing the spinal canal. OPLL produces cervical myelopathy from cord compression by the ossified ligament. Surgical decompression requires either anterior corpectomy with OPLL excision or posterior laminoplasty to expand canal capacity.

Region: Neck

Anatomical Data

Origin, Insertion & Supply

Origin	Posterior vertebral bodies (continuous cervical PLL)
Insertion	Becomes ossified — the calcified PLL extends into the spinal canal

Biomechanics

Function & Actions

Actions	In OPLL the ligament loses its normal function and becomes a rigid canal-occupying mass reducing spinal cord space

Clinical Relevance

Clinical Notes

OPLL is classified by the pattern: segmental (most common), continuous, mixed, and circumscribed types. CT shows the ossification in the canal at the posterior vertebral body level. Anterior surgery for OPLL carries a higher dural tear risk (the dura may be adherent to the OPLL). Posterior laminoplasty is safer for multilevel OPLL.

Pathology

Common Injuries & Conditions

OPLL Cervical Myelopathy

Ossified PLL narrowing the cervical canal producing myelopathy managed with laminoplasty or anterior corpectomy with excision.