Diagnosis and surgical management of intraspinal synovial cysts: report of 19 cases.

OBJECTIVE Synovial cysts of the vertebral facet joints are a source of nerve root compression. Different surgical procedures are in use, but no consensus has been formed so far as to which method should be used in synovial cysts. To clarify the role of surgical management, the efficacy of operative procedures and factors influencing the outcome in our own series of 19 patients treated between 1994 and 1998 were analysed. METHODS Nineteen patients with a mean age of 65 years underwent surgery for medically intractable radicular pain or neurological deficits caused by synovial cysts. The patients' records were retrospectively analysed for neurological deficits, cysts diameter, operative approach, segmental hypermobility, and clinical outcome; CT and MRI were analysed for additional degenerative changes. RESULTS In 17 patients an excellent result and in two patients a good postoperative result was achieved. Twelve patients were found to have hypermobility of the facet joints and six had spondylolisthesis. There was no correlation between cyst diameter, operative approach, and outcome. No intraoperative or postoperative complications occurred. CONCLUSIONS Age and hypermobility may play a part in the aetiology of facet joint synovial cysts. As all operative strategies showed equally good clinical outcome, total excision via a small flavectomy as the least invasive approach should be considered therapy of choice in patients with cysts causing neurological deficits.