Symptomatic intraspinal synovial cysts: opacification and treatment by percutaneous injection.

Intraspinal synovial cysts are usually located in the lower lumbar spine in association with osteoarthritis of the facet joints, and they are most accurately diagnosed by using CT. Surgical removal of intraspinal synovial cysts implicated in the development of radiculopathy has resulted in symptomatic relief. A nonoperative method of treatment consists of CT-guided needle placement into the facet joint adjacent to the cyst, followed by injection of contrast material to show communication between the joint and the cyst and injection of corticosteroids. Three outpatients were treated in this fashion without complications. Complete relief of symptoms was achieved in two cases and partial relief was achieved in one. Follow-up CT scans performed 2 months after the procedure showed no change in the size of the cysts in two of the patients. A 6-month follow-up CT scan in the third patient, however, showed significant improvement in cyst size. These preliminary results suggest that this procedure is an alternative to surgical management of intraspinal synovial cysts.