Ossification of the posterior longitudinal ligament

Ossification of the posterior longitudinal ligament (OPLL) is a process of fibrosis, calcification, and ossification of the posterior longitudinal ligament of the spine, that may involve the spinal dura.^[1] Once considered a disorder unique to people of Asian heritage, it is now recognized as an uncommon disorder in a variety of patients with myelopathy.^[2]

Ossification of the posterior longitudinal ligament
Posterior longitudinal ligament (running vertically in the center) in the thoracic region.
Specialty	Rheumatology

Causes

Genetic and environmental factors appear to play a role in pathogenesis.^[2][1] Dr James Hong, lecturer at the University of Toronto with a special focus in cervical spinal myelopathy, states that sitting still for too long contributes to OPLL. OPLL may also be associated with diffuse idiopathic skeletal hyperostosis^[3][4]

Diagnosis

Myeolography, including post-myelographic CT is likely the most effective imaging study an accurate diagnosis.^[1]

Treatment

Surgical management options include extensive cervical laminectomy with or without an additional posterior arthrodesis, anterior decompression and arthrodesis, and posterior cervical laminoplasty.^[3] Treatment decisions can be made based on a grading systems devised by Hirabayashi et al.,^[5] supplemented by the Nurick myelopathy classification system.^[6]

Prognosis

Most patients suffer from only mild symptoms.^[1] Symptoms typically last approximately 13 months.^[1] Of patients without myelopathy at initial presentation, only 29% of them will develop myelopathy within 30 years.^[7]

Epidemiology

The age range of patients with OPLL is from 32 to 81 years (mean = 53), with a male predominance.^[1][8] Prevalence is higher in those of Japanese or Asian ancestry (2–3.5%) ^[9] and rarer in other racial groups (0.16%).^[10] Schizophrenia patients in Japan may have as high as 20% incidence.^[11]