Unilateral Degenerative Facet Joint Pathology Eliciting Rapidly Progressive Cervical Spondylotic Myelopathy.

Cervical spondylotic myelopathy (CSM) is a common age-related disease, but little is known concerning the impact of cervical facet degeneration in patients suffering from CSM without degenerative cervical spondylolisthesis or cervical instability. We report an instructive case of CSM with rapid neurological deterioration in which unilateral degenerative facet joint pathology at the affected spinal level and impressive radiological findings were observed. A 70-year-old female progressively developed C5 segmental myelopathy without any trauma within a two-week period. Radiological findings revealed C3-4 spinal canal stenosis with the emergence of increased intramedullary signal intensity on T2-weighted magnetic resonance imaging, articular surface damage at the left C3-4 facet joint on computed tomography, and unilateral "facet joint gap" on cervical radiogram, but did not meet the criteria of cervical instability or spondylolisthesis. This case suggests that some types of severe degenerative changes in cervical facet joints may contribute to cervical myelopathy, especially in cases with progressive neurological deterioration.