Clinical course of patients with ossification of the posterior longitudinal ligament: a minimum 10-year cohort study

J Neurosurg. 2004 Mar;100(3 Suppl Spine):245-8. doi: 10.3171/spi.2004.100.3.0245.


Object: Ossification of the posterior longitudinal ligament (OPLL) may produce quadriplegia. The course of future neurological deterioration in patients with radiographic evidence of OPLL, however, is not known. The authors conducted a long-term follow-up cohort study of more than 10 years to clarify the clinical course of this disease progression.

Methods: A total of 450 patients, including 304 managed conservatively and 146 treated by surgery, were enrolled in the study. All patients underwent neurological and radiographical follow-up examinations for a mean of 17.6 years. Myelopathy was graded using Nurick classification and the Japanese Orthopaedic Association scale. Fifty-five (17%) of 323 patients without myelopathy evident at the first examination developed myelopathy during the follow-up period. Risk factors associated with the evolution of myelopathy included greater than 60% OPLL-induced stenotic compromise of the cervical canal, and increased range of motion of the cervical spine. Using Kaplan-Meier analysis, the myelopathy-free rate in patients without first-visit myelopathy was 71% after 30 years. A significant difference in final functional outcome was not observed between nonsurgical and surgical cases in which preoperative Nurick grades were 1 or 2. In patients with Nurick Grade 3 or 4 myelopathy, however, only 12% who underwent surgery eventually became wheelchair bound or bedridden compared with 89% of those managed conservatively. Surgery proved ineffective in the management of patients with Grade 5 disease.

Conclusions: Results of this long-term cohort study elucidated the clinical course of OPLL following conservative or surgical management. Surgery proved effective for the management of patients with Nurick Grades 3 and 4 myelopathy.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Cervical Vertebrae
  • Cohort Studies
  • Disabled Persons
  • Female
  • Follow-Up Studies
  • Humans
  • Male
  • Middle Aged
  • Ossification of Posterior Longitudinal Ligament / complications
  • Ossification of Posterior Longitudinal Ligament / physiopathology
  • Ossification of Posterior Longitudinal Ligament / surgery
  • Ossification of Posterior Longitudinal Ligament / therapy*
  • Range of Motion, Articular
  • Risk Factors
  • Spinal Cord Diseases / etiology
  • Spinal Cord Diseases / physiopathology
  • Spinal Stenosis / etiology
  • Spine / physiopathology
  • Survival Analysis
  • Treatment Failure