[Lumbar intraspinal synovial cysts: imaging and treatment by percutaneous injection. Report of thirteen cases].

Purpose: The CT and MR imaging findings in 13patients with lumbar intra spinal synovial cysts were retrospectively analysed and the results of facet corticosteroid injection were evaluated.
Patients and Methods: Over a 7 year period, 13patients with radicular pain were identified as having lumbar intra spinal synovial cysts. They ranged from 42 to 87 years of age. All patients were evaluated by CT without contrast material and underwent facet arthrography associated with corticosteroid injection and CT arthrography. MR imaging was performed in all patients either before or after percutaneous treatment. CT scans and MR images were reviewed and patient outcome was evaluated at 1and 6month followup.
Results: CT scan revealed a cystic structure adjacent to a degenerated facet joint in 9 patients (69% sensitivity). MRI showed more accurately the cyst on T2 weighted and/or axial images. Complete or good relief of radicular pain and functional restrictions were achieved in 9 patients (69%) at 1 month follow up, still to be found in 6patients (46%) at 6months.
Conclusion: In patients with radiculopathy and facet degenerative changes, intra spinal synovial cysts must be looked for. Facet corticosteroid injection is a useful alternative to surgical removal.