Extract
Rheumatoid arthritis frequently involves the cervical spine,
especially the atlantoaxial joint, often resulting in atlantoaxial
subluxation. In series ranging in size from seventy-three to 333 patients, 25%
to 60% of patients with rheumatoid arthritis had this
lesion1.
Atlantoaxial subluxation sometimes causes devastating cervical myelopathy in
these patients.Ossification of the posterior longitudinal ligament appears as an abnormal
radiopacity along the posterior margins of the vertebral bodies as seen on
lateral radiographs. It also may cause spinal cord compression, resulting in
myelopathy2.
Tsukimoto was probably the first to describe ossification of the posterior
longitudinal ligament in Japan, on the basis of autopsy findings, in
19603. Since then,
many reports of this disease in both the cervical and the thoracic spine have
been published in Japan. Tsuyama and Nakanishi et al. reported that the
prevalence of radiographically demonstrated ossification of the posterior
longitudinal ligament was 2% (121 of 6034) and that this value increased to
11% (eleven of 104) among patients over the age of sixty years in
Japan4,5.
Only a limited number of cases of ossification of the posterior longitudinal
ligament have been reported among non-Japanese
individuals6,7.
Satomi and Hirabayashi reported that ossification of the posterior
longitudinal ligament was observed on the cervical radiographs of
approximately 2.1% of 1000 outpatients in east Asian countries, including
Japan, compared with 0.2% of 854 subjects at the Mayo Clinic and 0.6% of 490
subjects in
Hawaii2.