Microdecompression for lumbar synovial cysts: an independent assessment of long term outcomes

BACKGROUND: Outcomes of surgical intervention for lumbar synovial cysts have been evaluated in the short and intermediate term. Concerns regarding cyst recurrence, the development of late instability at the involved level, and instability/stenosis at adjacent levels (when concomitant) fusion is performed suggest that long term follow-up is needed. This study aims to fill that void. METHODS: Forty-six patients operated by a single surgeon not involved in the study were followed up long term at an average of 9.7 years (range 5 to 22 years) post-operatively. All patients underwent decompression (+/- concomitant arthrodesis in the presence of associated degenerative spondylolisthesis) using the operative microscope for magnification/illumination. Outcomes were assessed using a customized questionnaire evaluating: relief of pain/claudicant symptoms, numbness/parasthesias, and weakness; as well as late onset low back pain, new radicular symptoms, need for additional surgery, and patient satisfaction. Outcomes in patients with or without fusion were compared as well. RESULTS: 87% of patients noted resolution of their pre-operative pain, numbness, and weakness. 28% of patients developed late onset low back pain. 17% developed late onset radicular symptoms in a new nerve root distribution. 15% required subsequent additional surgery. 89% of patients were satisfied with the surgical outcome. No differences were found for any outcome measure between patients undergoing concomitant fusion and those undergoing decompression alone using the two-sample t-test. CONCLUSION: This study provides outcome data at an average of nearly ten years post-operative. This information should allow surgeons to provide realistic expectations for their patients regarding outcomes and should enhance the informed consent and surgical decision-making process.