Four hundred thirty-seven patients with lumbar spinal stenosis were randomized to receive either unilateral laminotomy with crossover (UL, n=122), bilateral laminotomy (BL, n=119), or spinous process osteotomy (SPO, n=117). The primary outcome of interest was the mean change in Oswestry Disability Index (ODI) score at five years. Secondary outcomes included the proportion of patients classified as success (≥30% reduction in ODI), changes in EQ-5D, Zurich Claudication Questionnaire (ZCQ) scores, Numeric Rating Scale (NRS) for leg and back pain, Global Perceived Effect (GPE) scores, and rates of subsequent spinal surgery. Outcomes were assessed at baseline, 3 months, 1 year, 2 years, and 5 years. Overall, the results of the study revealed no significant differences in ODI improvement or any secondary outcomes between the three techniques. These findings suggest that all three midline-preserving decompression methods yield similar long-term outcomes, and surgical choice may be guided by surgeon preference and experience.