This is a three-centre randomised controlled trial in which 200 patients with symptomatic lumbar spinal stenosis will be randomised into one of two treatment arms. The patients in the surgical arm will undergo decompression of the neural structures by use of any open or minimally invasive (MIS) technique with or without fusion; the patients in the non-surgical arm will undergo imaging assisted percutaneous interspinous spacer insertion with fusion.~The primary outcome of the study will be the Oswestry Disability Index. Secondary outcomes will include motor amplitude and degree of denervation activity obtained by means of nerve conduction studies and electromyography.~Patient-reported outcome measures will be also used as secondary outcomes.
Symptomatic lumbar spinal stenosis is the most common indication for spinal surgery. However, more than one-third of the patients undergoing surgery for lumbar stenosis report dissatisfaction with the results. On the other hand, conservative treatment has shown positive results in some cases. This trial will compare the outcomes of surgical versus non-surgical treatment for lumbar stenosis.