Recurrent back and leg pain and cyst reformation after surgical resection of spinal synovial cysts: Systematic review of reported postoperative outcomes

BACKGROUND CONTEXT: With improvements in neurological imaging, there are increasing reports of symptomatic spinal synovial cysts. Surgical excision has been recognized as the definitive treatment for symptomatic juxtafacet cysts. However, the role for concomitant fusion and the incidence of recurrent back pain and recurrent cyst formation after surgery remain unclear. PURPOSE: To determine the cumulative incidence of postoperative symptomatic relief, recurrent back and leg pain after cyst resection and decompression, and synovial cyst recurrence. STUDY DESIGN: Systematic review of the literature. PATIENT SAMPLE: All published studies to date reporting outcomes of synovial cyst excision with and without spinal fusion. OUTCOME MEASURES: Cyst recurrence and Kawabata, Macnab, Prolo, or Stauffer pain scales. METHODS: We performed a systematic literature review of all articles published between 1970 and 2009 reporting outcomes after surgical management of spinal synovial cysts. RESULTS: Eighty-two published studies encompassing 966 patients were identified and reviewed. Six hundred seventy-two (69.6%) patients presented with radicular pain and 467 (48.3%) with back pain. The most commonly involved spinal level was L4-L5 (75.4%), with only 25 (2.6%) and 12 (1.2%) reported synovial cysts in the cervical or thoracic area, respectively. Eight hundred eleven (84.0%) patients were treated with decompressive surgical excision alone, whereas 155 (16.0%) received additional concomitant spinal fusion. Six hundred fifty-four (92.5%) and 880 (91.1%) patients experienced complete resolution of their back or leg pain after surgery, respectively. By a mean follow-up of 25.4 months, back and leg pain recurred in 155 (21.9%) and 123 (12.7%) patients, respectively. Sixty (6.2%) patients required reoperation, of which the majority (n=47) required fusion for correction of spinal instability and mechanical back pain. Same-level synovial cyst recurrence occurred in 17 (1.8%) patients after decompression alone but has been reported in no (0%) patients after decompression and fusion. CONCLUSIONS: Surgical decompression results in symptomatic resolution in the vast majority of patients; however, recurrent back pain occurs in a significant number of patients. Cyst recurrence occurs in less than 2% of patients but has never been reported after cyst excision with concomitant fusion. The lack of cyst recurrence after concomitant fusion supports the need to investigate the value of fusion of the involved motion segment in the treatment of symptomatic synovial cysts of the spine.