Introduction: This observational study is designed to test the equivalence between the clinical effectiveness of microdecompression and laminectomy in the surgical treatment of central lumbar spinal stenosis. Lumbar spinal stenosis is the most frequent indication for spinal surgery in the elderly, and as the oldest segment of the population continues to grow its prevalence is likely to increase. However, data on surgical outcomes are limited. Open or wide decompressive laminectomy, often combined with medial facetectomy and foraminotomy, was formerly the standard treatment. In recent years a growing tendency towards less invasive decompressive procedures has emerged. Many spine surgeons today perform microdecompression for central lumbar spinal stenosis.

Prospectively registered treatment and outcome data are obtained from the Norwegian Registry for Spine Surgery (NORspine).

Inclusion Criteria:

• Diagnosis of central lumbar spinal stenosis
• Operation in ≤2 lumbar levels with either open decompressive laminectomy, bilateral microdecompression or unilateral microdecompression for bilateral decompression in the time period between October 2006 and December 2011
• Included in the NORspine registry

Exclusion Criteria:

• History of lumbar fusion
• Previous surgery in the lumbar spine
• Discectomy as part of the decompression
• Associated pathological entities such as disc herniation, spondylolisthesis or scoliosis.

patients who had operation in ≤2 lumbar levels with either open decompressive laminectomy, bilateral microdecompression or unilateral microdecompression for bilateral decompression in Norway in the time period between October 2006 and December 2011