Ossification of the posterior longitudinal ligament of the cervical spine and SAPHO syndrome.

We describe a case of cervical cord compression due to ossification of the posterior longitudinal ligament of the spine (OPLLS) in a 43-year-old Vietnamese patient with SAPHO syndrome (synovitis, acne, pustulosis, hyperostosis, and osteitis). Idiopathic OPLLS is mainly reported in 50- to 60-year-old men, particularly in Japanese, with a prevalence of 2%. Cervical myelopathy may occur. In addition to OPLLS in patients of Asian origin, the condition has also been described in association with ossifying diseases, including ankylosing spondylitis (AS) and diffuse idiopathic skeletal hyperostosis (DISH) but not previously, to our knowledge, with SAPHO syndrome.