This study aims to compare the outcomes of surgical treatment and conservative treatment at medium- and long-term period (minimum 2 years) in patients with lumbar stenosis who come to the observation of the PI's Team at the Rizzoli Orthopaedic Institute, through a series exhaustive questionnaires to self-administer to patients in order to define a path of "decision-making" as effective as possible for the patient and the doctor.

Non-surgical treatment:

Conservative treatment may include different approaches, such as analgesics, anti-inflammatories, muscle relaxants, physical therapy, Global Postural Rehabilitation, magnetic therapy, laser therapy, TENS, massage, cognitive-behavioral therapy and all those procedures that can bring benefit in back and legs pain.

Surgical treatment:

Surgical treatment of lumbar stenosis is the decompression surgery which relieves the nerve structures to prevent permanent neurological damage. Decompression can be made on one or more segments of the spine and can be done with laminectomy, hemilaminectomy, laminotomy.

During a laminotomy part of the vertebral lamina is removed above and below the compressed nerve. The opening created is sometimes enough to relieve the compression on the nerve. In most cases, also the disc material and bone spur that compress the nerve are removed.

During a laminectomy the vertebral lamina is completely removed, along with the disc and the bone material that compress the nerves. The opening produced by the removal of the lamina is protected by back muscles and ligaments.

If the damage has occurred at several levels and bone of the vertebral support structures must be removed to achieve decompression, it can be performed a stabilization surgery with vertebral bone fusion (arthrodesis) in order to avoid instability of the column. Fusion is carried out to eliminate the mobility between different vertebrae and it is achieved using bone derived from the patient's iliac crest or from a donor. The bone gradually grows and melts with the same vertebrae. This limits the movements that may have been one of the causes of back pain. It takes about six months for it to achieve a solid bony spinal fusion.

Inclusion Criteria:

• Confirmatory imaging study (MRI or CT) showing lumbar spinal stenosis at one or more levels (L2 to sacrum) defined as narrowing of the central spinal canal, lateral recesses, or neural foramens due to encroachment on the neural structures by the surrounding bone and soft tissue.

Exclusion Criteria:

• Patients are not eligible if they have evidence of instability on lateral flexion- extension radiographs, defined as a change of #10° of angulation of adjacent segments by Cobb measurement or a change of more than 4 mm of anteroposterior or posteroanterior translation.