Decompression surgery has proved to be effective for Lumbar Spinal Stenosis (LSS) with persistent pain. But the efficiency of the surgery for degenerated LSS remain uncertain and is the subject of this study. This is a multiple center open-label randomised trial. Patients were randomly allocated to surgical group or a nonoperative group. Because of the procedure , neither patients nor investigators were blinded. The primary outcome is the change of symptom measure by the Oswestry disability index 6, 12, and 24 months after procedure.

This study will use a randomised controlled trial to access the efficiency of the surgery for degenerated LSS. Patients aged 50 years or older, had LSS will be invited to take part. Patients will be randomised divided into 2 arms. The participants in the intervention arm will have decompression surgery ; those randomised to the control arm will receive current standard conservative treatment methods.

Patients were clinically assessed at baseline (the day of surgery or treatment), and at 6,12 and 24 months afterwards. The primary outcome will be the pain release , categorised according to Oswestry disability index.

Inclusion Criteria:

• Clinical symptoms: back pain radiation to lower limbs or buttocks; fatigue or loss of sensation in the lower limbs aggravated by walking.
• Persistent pain without progressive neurologic dysfunction
• Duration of symptoms and signs for more than 6 months
• Severity of the disease justifying either surgical or nonoperative treatment

Exclusion Criteria:

• severe LSS with intractable pain and progressive neurologic dysfunction, suggesting forthcoming surgical treatment
• spinal stenosis not caused by degeneration
• lumbar herniated disc diagnosed during the last 12 months
• neurologic disease causing impaired function of the lower limbs