Minimally Invasive Surgical Decompression without Fusion for the Treatment of Lumbar Synovial Cysts: Feasibility and Long-Term Outcomes.

Background: Lumbar synovial cysts (LSCs) can cause painful radiculopathy and sensory and/or motor deficits. Historically, first-line surgical treatment has been decompression with fusion. Recently, minimally invasive laminectomy without fusion has shown equal or superior results to traditional decompression and fusion methods.

Objective: This study investigates the long-term efficacy of minimally invasive laminectomy without fusion in the treatment of LSC as it relates to the rate of subsequent fusion surgery.

Methods: A retrospective review was performed over a 10-year period of patients undergoing minimally invasive laminectomy for symptomatic LSCs. The primary end point was the rate of revision surgery requiring fusion.

Results: Eighty-five patients with symptomatic LSCs underwent minimally invasive laminectomy alone January 2010-August 2020 at our institution. The most common location was L4-5 (72%). Preoperative imaging identified spondylolisthesis (grade 1) in 43 patients (57%), none of which was unstable on available dynamic radiographs. Average procedure duration was 93 minutes, with 78% of patients discharged home on the same day of surgery. Over 46 months of mean follow-up, 17 patients (20%) required 19 revision operations. Of those operations, 16 were spinal fusions (17.6%). Median time to fusion surgery was 36 months. There were no identifiable risk factors on multivariate regression analysis that predicted the need for fusion.

Conclusions: Minimally invasive laminectomy is an effective first-line treatment for symptomatic LSCs and avoids the need for fusion in most treated patients. Of our patients, 18% required a fusion over 46 months, suggesting that further studies are required to guide patient selection.