Cervical facet joint effusion: A sign of instability in cervical degenerative spondylolisthesis

The aim of this study was to trace the association between cervical facet joint effusion and cervical degenerative spondylolisthesis (CDS). CDS has not received as much attention as its lumbar counterpart. Identification of features of instability on magnetic resonance imaging (MRI) is crucial to avoid missing presence of CDS.

The authors retrospectively reviewed cervical spine MRI scans and upright lateral flexion-extension radiographs of 17 consecutive patients at a single institution between January 2017 and June 2018 that revealed CDS. Presence of cervical facet joint effusion and CDS was recorded. Data were analyzed to deduce possibility of an association between cervical facet joint effusion and CDS.

Seventeen patients fulfilled the inclusion criteria of cervical spondylotic myelopathy associated with CDS. Out of these, 10 patients revealed facet joint effusion at C3-C4 (4 patients) and C4-C5 (6 patients) levels. The mean age of patients was 65.8 years (49-79) and M:F was 2.2:1. Amount of facet joint effusion varied and ranged from 1.6 mm to 4.7 mm on the axial images. Ten patients (58.82%) demonstrated facet joint effusion associated with mobile CDS. Seven patients (41.17%) with CDS and without facet effusion did not demonstrate mobility of more than 0.5 mm in flexion-extension radiographs.

The current study acknowledges the association of "cervical facet effusion" and CDS. Clinically measurable facet joint effusion on MRI suggests the need for further attempts to diagnose CDS.