Anatomy. The structure of the body or its parts.

Annulus fibrosis. The tough, flexible outer band of the disc.

Bone scan. An imaging test that helps detect fractures, tumors, infections, and arthritis.

Bone spur. A bony projection that grows along the edge of a bone. The extra bone can cause pain when it rubs against other bones or nearby nerves.

Cartilage. Tough, elastic connective tissue that forms a firm, flexible surface at the ends of bones and helps the joints move more smoothly.

CAT scan (computerized axial tomography). A test that uses X-rays and computer analysis to create three-dimensional images of the body to help physicians diagnose and treat medical conditions. Also called CT scan.

Cauda equina syndrome. A serious condition caused by compression of the nerves in the lower portion of the spinal canal. If left untreated, it can lead to a loss of bowel or bladder function and weakness or a loss of sensation in both legs.

Cerebrospinal fluid. The fluid contained within the brain and around the spinal cord.

Compression. An abnormal amount of pressure, for example, on the vertebrae or spinal nerves.

Corticosteroid. A class of medication used to reduce inflammation. Corticosteroids can be taken orally as a pill, injected, inhaled, applied to the skin, or given intravenously.

CT scan. See CAT scan.

Decompression. Removal or relief of pressure from, for example, the vertebrae or spinal nerves.

Degenerative. A condition that grows worse over time.

Degenerative disc disease. A gradual deterioration of the cushioning discs between the vertebrae, which may result in pain and stiffness. Not actually a disease, but a normal part of the aging process and very common.

Degenerative spondylolisthesis. A condition that causes a vertebra in the spine to slip forward and out of line with the vertebra below.

Disc. Shock-absorbing pads of cartilage between the vertebrae that allow rotation and forward and backward motion of the spine. Discs also cushion vertebrae to protect them from impact.

Epidural steroid injections. Medication administered into the spine with a needle and syringe to reduce inflammation and swelling.

Extension. An anatomical term of motion. Spinal extension is achieved by bending backward or standing up straight. Extension is the opposite of flexion.

Facet joints. Joints of the spine that connect all the vertebrae and allow motion in the spinal column.

Facetectomy. A surgical procedure to remove part or all of a degenerated facet joint and prevent it from pinching a nerve.

Flexion. An anatomical term of motion. Spinal flexion is achieved by bending forward or sitting. Flexion is the opposite of extension.

Foramen (plural, foramina). A natural opening or passage in the vertebrae of the spine through which spinal nerves travel.

Foraminotomy. A surgical procedure to enlarge the passageway (the foramen) where a spinal nerve exits the spinal canal to eliminate pressure on the nerve.

Fusion. Spine surgery that permanently joins (fuses) two or more vertebrae together.

General anesthesia. A drug or substance that puts a person into an unconscious state and creates a temporary loss of feeling throughout the body.

Herniated disc. When one of the small, spongy discs between two vertebrae is damaged and bulges out of position. Also called a ruptured or slipped disc.

Implanted device. An object inserted into the body for prosthetic, therapeutic, or diagnostic purposes.

Incontinence. Inability to control urination or defecation.

Interspinous spacer. See X-STOP Spacer.

Intravenous. Delivered through the veins.

Intravertebral disc. A disc situated between two neighboring vertebrae.

Isthmic spondylolisthesis. A condition caused by a stress fracture in a part of a vertebra, allowing the vertebra to slip forward over the vertebra below.

Lamina. The bony plate that protects your spinal cord. It is often described as the “roof” of the spinal canal.

Laminectomy. Surgery to remove the lamina, the bony plate that protects your spinal cord. The purpose is to allow more room for the spinal nerves. Also called decompressive laminectomy.

Laminotomy. A procedure that makes a hole in the lamina and removes a small portion of the bone. The procedure is used to treat bone spurs, spinal stenosis, and herniated discs.

Ligaments. Tough, flexible connective tissues that hold one bone to another in the body and help strengthen and stabilize joints.

Ligamentum flavum. A large, long, elastic band of soft tissue that runs along the inside of the spinal canal.

Local anesthesia. A drug or substance that creates a temporary loss of pain sensation in a specific area and does not put a person into an unconscious state.

Lumbar level. The lower back.

Lumbar spinal stenosis (LSS). A disease that causes a narrowing of the spinal canal, which may pinch spinal nerves and cause painful symptoms.

Lumbar spine. The lower part of the spine located between the ribs and the hip bones. There are five lumbar vertebrae, which are identified as L1 to L5 (the lowest).

Meningitis. Inflammation of the membranes that envelop the brain and spinal cord by bacteria or virus.

Minimally invasive. Any surgical technique that does not require a large incision. This may minimize bleeding and trauma to the body, allow for shorter hospital stays, and reduce postoperative pain and recovery time.

MRI (magnetic resonance imaging). A noninvasive form of medical imaging that uses magnetic fields to create detailed two-dimensional views of the inside of your body. These images are used by physicians in diagnosing and treating medical disorders.

Myelogram. A test involving injection of dye into the spinal column, which highlights the spinal cord and nerves.

Neurogenic intermittent claudication (NIC). Pain and discomfort in the low back, buttocks, and legs.

Nerves. Extremely sensitive cordlike structures of fibers that use electrical and chemical signals to relay messages between the brain and other areas of the body.

Neurosurgeon. A medical doctor trained in the diagnosis and treatment of disorders of the brain, spine, spinal cord, and nerves.

NIC. See neurogenic intermittent claudication.

Nucleus pulposus. A soft, gel-like substance inside the disc.

Nonfusion. Treatment for a spine disorder that does not involve permanently joining vertebrae together.

Obesity. A condition defined as an abnormal or excessive fat accumulation that presents a risk to health.

Orthopedic spine surgeon. A doctor who specializes in back surgery.

Osteoarthritis. A condition caused by breakdown of cartilage (the slippery material at the ends of bones that absorbs the shock of movement) in one or more joints in the fingers, hips, knees, feet, and the spine, neck, and lower back. It is the most common joint disease affecting middle-aged and older people. Also called degenerative joint disease.

Osteophytes. Bone spurs that form along the joints and that can grow into—and narrow—the spinal canal area.

Outpatient. A patient who comes to the hospital for diagnosis or treatment but does not need a bed for an overnight stay.

Peripheral neuropathy. Damage to the nerves that carry information to and from the brain and spinal cord. Symptoms of peripheral neuropathy vary, depending on the cause and the location of the nerve damage, but can include numbness and pain, usually in the hands, arms, legs, or feet; tingling or burning; loss of sensation; and inability to control muscles.

Physical therapy. The treatment of injuries or disorders using physical methods, such as exercise, massage, or the application of heat.

Pulmonary embolism. Closure of the pulmonary artery by a blood clot.

Ruptured disc. When one of the small, spongy discs that cushions the vertebrae is damaged and breaks open.

Sciatica. Often misused as a catch-all term for leg pain. Sciatica is medically defined when a spinal disc extends beyond its normal position and irritates the nerves that branch out from the spinal column and form the sciatic nerve, which runs from the base of the spine to below the knee. Pain from sciatica is present in these areas.

Spinal canal. A passageway formed by bone that runs through the vertebral column and houses and protects the spinal cord.

Spinal cord. A bundle of nerves enclosed in the spinal canal. The spinal cord carries messages between the brain and the rest of the body.

Spinal fusion. A surgical procedure in which two or more vertebrae are permanently joined together (“fused”) to prevent motion between them.

Spinal stenosis. A narrowing of the spinal canal.

Spinous processes. Slender bone projections that stick out of your vertebrae. These are the bones you feel when you touch your lower back.

Spondylolisthesis. A condition in which one vertebra slips forward over the vertebra below it.

Supraspinous ligament. A ligament that connects the tips of the spinous processes.

Vascular claudication. An aching, tired, and sometimes burning pain in the legs due to poor blood flow in the arteries of the legs.

Vertebra (plural, vertebrae). One of the thirty-three bony segments that form the human spinal column. There are five lumbar vertebrae.

X-ray. Electromagnetic radiation used in various forms of imaging tests, such as a bone scan or CAT scan.

X-STOP Spacer. A small implant that fits between the spinous processes to relieve pressure on spinal nerves. FDA-approved for the treatment of symptoms of lumbar spinal stenosis.

Zurich Claudication Questionnaire (ZCQ). A patient-completed survey that measures specific aspects of lumbar spinal stenosis. ZCQ is an international standard that has been scientifically validated.