A retrospective matched pair analysis study on single level unilateral L4/5 hemi-laminectomy with and without the use of the Aperius percutaneously-inserted inter-spinous spacer in patients with bilateral lateral recess stenosis with symptomatic unilateral symptoms. A possible alternative to bilateral laminectomy. At 6 months, Aperius patients had better radiographic outcomes(intervertebral angle and intervertebral foraminal height) and bodily pain scores. We conclude that unilateral percutaneous decompression hemilaminectomy with interspinous spacer augmentation is safe and effective.