Summary
Background: Myelopathy caused by multilevel ossification of yellow ligament is an uncommon in the thoracic spine, which creates diagnostic difficulty and typical management by decompressive
laminectomy or laminoplasty in the thoracic spine is advised for all cases.
Case report: We report two cases of the Chinese males who presented with clinical evidence of chronic and progressive thoracic spinal cord compression which included: bilateral leg weakness, spastic
gait, lower extremities and perineum paresthesias, urinary incontinence. Neurological examination revealed severe spastic paraparesis, absence of abdominal reflexes and reduction of the
sensory function below compressive level. MRI and CT scans of the thoracic spine confirmed the presence of multilevel ossification of yellow ligament. A thoracic decompressive laminectomy
resulted in an good post-operative outcome.
Conclusion: Multilevel ossification of ligamentum flavum is not an uncommon cause of myelopathy in the Chinese population and should be treated as early as possible. MRI and even CT scan examinations
may define the presence of thoracic OYL. Posterior decompression, especially with en bloc dissection of laminae, gives satisfactory results.

Keywords: contiguous, multiple-level ossification of yellow ligamen, thoracic cord compression, chinese patients