Ossification of the posterior longitudinal ligament
A spinal ligament disorder causing myelopathy, once thought Asian-specific.
Ossification of the posterior longitudinal ligament (OPLL) is a condition where the posterior longitudinal ligament in the spine undergoes fibrosis, calcification, and ossification, sometimes affecting the spinal dura. It was once thought to occur only in people of Asian descent, but is now known to be an uncommon cause of myelopathy across different patient groups.
The condition likely results from a mix of genetic and environmental factors. It may also be linked to diffuse idiopathic skeletal hyperostosis.
For diagnosis, myelography followed by a post-myelographic CT scan is considered the most effective imaging method for an accurate result.
Surgical treatment options include extensive cervical laminectomy (with or without additional posterior arthrodesis), anterior decompression and arthrodesis, or posterior cervical laminoplasty. Decisions are guided by the grading system developed by Hirabayashi and colleagues, along with the Nurick myelopathy classification.
Most patients experience only mild symptoms, which typically last about 13 months. Among those without myelopathy at first diagnosis, only 29% develop it within 30 years.
Patients range in age from 32 to 81 years, with an average of 53, and the condition is more common in men. Prevalence is higher in people of Japanese or Asian ancestry (2–3.5%) and much rarer in other groups (0.16%). In Japan, up to 20% of schizophrenia patients may have OPLL.
Quick Facts
- Field
- Rheumatology
Facts from the source article.
Lore & Background
OPLL is a process of fibrosis, calcification, and ossification of the posterior longitudinal ligament, which may involve the spinal dura. Genetic and environmental factors appear to play a role in pathogenesis. OPLL may also be associated with diffuse idiopathic skeletal hyperostosis.
Reader's Guide
Ossification of the posterior longitudinal ligament is significant as a cause of myelopathy that was historically mischaracterized as unique to Asian populations. Its recognition in diverse patient groups has broadened diagnostic awareness. Diagnosis is most effectively made via myelography, including post-myelographic CT. Treatment options include extensive cervical laminectomy with or without posterior arthrodesis, anterior decompression and arthrodesis, and posterior cervical laminoplasty, with decisions guided by the Hirabayashi grading system and the Nurick myelopathy classification. Prognosis is generally mild: most patients have only mild symptoms lasting about 13 months, and only 29% of those without myelopathy at initial presentation develop it within 30 years. The condition shows a male predominance, with a mean age of 53 years. Prevalence is higher in Japanese or Asian ancestry (2–3.5%) and rarer in other groups (0.16%), with a notably high incidence of 20% among schizophrenia patients in Japan.
Did You Know?
- OPLL was once considered a disorder unique to people of Asian heritage but is now recognized in a variety of patients with myelopathy.
- Schizophrenia patients in Japan may have as high as 20% incidence of OPLL.
- Only 29% of patients without myelopathy at initial presentation will develop myelopathy within 30 years.
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