TABLE 1.

Inclusion and Exclusion Criteria for the NORDSTEN-SST Trial With the Addition of the Specific Radiologic Requirements for This Study*

Inclusion criteria

Presence of clinical symptoms of spinal stenosis, such as neurogenic claudication or pain radiating bilaterally to the lower limbs

Nonresponse of at least three months of nonsurgical treatment

Radiological findings corresponding to the clinical symptoms of LSS. Central-stenosis or lateral recess stenosis.

Able to give informed consent and to answer the questionnaires

Over 18 years of age

Able to understand Norwegian, both spoken and written

*Preoperative and two years postoperative standing lateral x-rays of the lumbar spine

Exclusion criteria

Degenerative lumbar spondylolisthesis, with a slip ≥3 mm verified on standing plain x-rays in lateral view

Not willing to give written consent

Previous surgery at the level of stenosis

Fracture or former fusion in the thoracolumbar region

Cauda equina syndrome (bowel or bladder dysfunction) or fixed complete motor deficit

ASA classified 4 or 5

Over 80 years of age

Presence of lumbosacral scoliosis of more than 20°, verified on AP view

Presence of distinct symptoms in one or both legs, due to other diseases, for example, polyneuropathy, vascular claudication, or osteoarthritis

LSS at 4 or more levels

Unable to comply fully with the protocol, including treatment, follow-up, or study procedures (psychosocially, mentally, or physically)

The patient is participating in another clinical trial that may interfere with this trial