Spinal synovial cysts: clinical and therapeutic considerations

Synovial cysts are an important differential diagnosis in lumbar radiculopathy.

From 2000 to 2005, we treated 32 patients (22 female, 10 male) suffering from lumbar radiculopathy due to spinal synovial cysts. The mean age was 64 years (range 42-84). The clinical mix of cases at admission was: 10 patients with radiculating pain accompanied by sensory disturbances, 8 with neurogenic claudication, 7 with muscular weakness, 6 with radicular pain, and one with back pain only. The anatomical distribution was 10 cases at the L5/S1 level, 16 cases at L4/5, 5 cases at L3/4, and one case at L1/2. The average period from the first onset of symptoms to treatment was 9 months. Twenty-five cases were treated via a (limited) laminotomy only and 7 via hemilaminectomy. The cases were evaluated clinically at routine follow-up.

After a follow-up of between six months and three years, 15 patients were free of complaints, 13 had improved markedly, while 3 had considerable remaining complaints. One patient developed an instability requiring spinal fusion. We observed a local recurrence at the same site in one patient and three cases of synovial cysts on the contralateral joint at the same spinal level.

The operative removal of a spinal synovial cyst is beneficial in terms of treatment of the nerve root compression. In the majority of cases, a (limited) laminotomy is sufficient as an approach.