This multicentre observational study from the Norwegian Spine Registry compared microdecompression to open laminectomy for central lumbar spinal stenosis. It was designed as an equivalence study — asking not whether one technique is better, but whether they produce the same result. 885 patients across 34 departments were enrolled, with one-year Oswestry Disability Index change as the primary outcome.
When choosing between microdecompression and open laminectomy for central lumbar stenosis without instability, the functional outcome at one year is the same — the decision can reasonably turn on perioperative factors rather than expected efficacy.
This is an equivalence study, not a superiority trial, and that framing matters. The authors prespecified an 8-point ODI difference as the boundary of clinical equivalence (the accepted MCID). The observed difference of 1.3 points means you can counsel patients that technique choice will not meaningfully change how they feel at one year.
The clearest practical difference is hospital length of stay: microdecompression patients go home roughly 1.6 to 2.0 days sooner after propensity matching, a consistent finding across all analytical approaches. The authors propose this reflects reduced surgical trauma and earlier mobilization, though differing institutional protocols for minimally invasive surgery may also contribute.
For boards and clinical practice, remember the key exclusion criteria: this equivalence applies only to patients without prior lumbar surgery, without associated disc herniation, and without spondylolisthesis or degenerative scoliosis. Patients with radiologic instability were not included. The question of whether to add fusion in stenosis patients with spondylolisthesis remains a separate, contested decision.
This multicentre observational study from the Norwegian Spine Registry compared microdecompression to open laminectomy for central lumbar spinal stenosis. It was designed as an equivalence study — asking not whether one technique is better, but whether they produce the same result. 885 patients across 34 departments were enrolled, with one-year Oswestry Disability Index change as the primary outcome.
When choosing between microdecompression and open laminectomy for central lumbar stenosis without instability, the functional outcome at one year is the same — the decision can reasonably turn on perioperative factors rather than expected efficacy.
This is an equivalence study, not a superiority trial, and that framing matters. The authors prespecified an 8-point ODI difference as the boundary of clinical equivalence (the accepted MCID). The observed difference of 1.3 points means you can counsel patients that technique choice will not meaningfully change how they feel at one year.
The clearest practical difference is hospital length of stay: microdecompression patients go home roughly 1.6 to 2.0 days sooner after propensity matching, a consistent finding across all analytical approaches. The authors propose this reflects reduced surgical trauma and earlier mobilization, though differing institutional protocols for minimally invasive surgery may also contribute.
For boards and clinical practice, remember the key exclusion criteria: this equivalence applies only to patients without prior lumbar surgery, without associated disc herniation, and without spondylolisthesis or degenerative scoliosis. Patients with radiologic instability were not included. The question of whether to add fusion in stenosis patients with spondylolisthesis remains a separate, contested decision.