Clinical Outcomes and Radiologic Changes After Microsurgical Bilateral Decompression by a Unilateral Approach in Patients With Lumbar Spinal Stenosis and Grade I Degenerative Spondylolisthesis With a Minimum 3-Year Follow-Up

Despite small case series with retrospective design and the absence of a control group, our study suggests that bilateral decompression via a unilateral approach in patients with LSS and grade 1 DS showed good mid-term clinical outcomes, despite an increase in slip percentage.However, more marked increases in slippage were observed in patients with sagittal motion in spondylolisthesis levels on preoperative dynamic x-ray, than in patients without sagittal motion. Therefore, bilateral decompression via a unilateral approach can aggravate symptoms related to instability in patients with preoperative sagittal motion on dynamic x-ray, and needs a longer term follow-up than in our study.