Each year in the United States, more than 30,000 patients undergo back surgery for lumbar spinal stenosis, an abnormal narrowing or constriction of spaces in the back that provide pathways for spinal nerves. This disorder is the most common reason for back surgery in patients > 65 years of age and it usually develops due to changes in the spinal discs, joints, and/or ligaments. These changes can compress spinal nerves causing pain and difficulty with walking. Many patients with lumbar spinal stenosis benefit from conservative treatments, including: rest, nonsteroidal antiinflammatory drugs, muscle relaxants, and an appropriate program of physical therapy. Steroid injections may also be effective. If conservative treatments do not provide sufficient relief, back surgery may be needed.