Treatment of Lumbar Spinal Stenosis; Comparison of Two Different Surgical Methods; Mini-invasive Decompression to X-stop

The purpose of this study is to compare two surgery methods on lumbar spinal stenosis: minimal invasive decompression and X-stop. It is a prospective randomized multicenter study including patients with lumbar spinal stenosis on one or two levels, and neurogenic intermittent claudication. Effect assessment will include measures of pain and self-evaluated health condition, a full economical evaluation, and areal measurements (MR imaging and roentgen analyses)