Bone spur: Bony growth or rough edges of bone (a.k.a. osteophyte).

Decompression: A surgical procedure performed to relieve pressure and alleviate pain caused by the impingement of bone and/or disc material on the spinal cord or nerves.

Disc degeneration: Degeneration or wearing out of a disc. A disc in the spine may deteriorate or wear out over time. A deteriorated disc may or may not cause pain.

Discectomy: The surgical removal of part or all of an intervertebral disc, performed to relieve pressure on a nerve root or the spinal cord.

Excision: Removal by cutting away material, as in removing a disc.

Facet: A posterior structure of a vertebra which articulates (joins) with a facet of an adjacent vertebra to form a facet joint that allows motion in the spinal column. Each vertebra has a right and left superior (upper) facet and a right and left inferior (lower) facet.

Foramen: A normal occurring opening or passage in the vertebrae of the spine through which the spinal nerve roots travel.

Foraminotomy: Surgical opening or enlargement of the bony opening traversed by a nerve root as it leaves the spinal canal, to help increase space for that nerve.

Herniated disc: A condition, also known as a slipped or ruptured disc, in which the gelatinous core material of a disc bulges out of position and puts painful pressure on surrounding nerve roots.

Intervertebral foramen: An opening between vertebrae through which nerves leave the spine and extend to other parts of the body. Also known as neural foramen.

Kyphosis: A condition in which the upper back curves forward, sometimes leading to the appearance of a hump in the back. Kyphosis may result from years of poor posture, spine fractures associated with osteoporosis, trauma or developmental problems.

Lamina: The flattened or arched part of the vertebral arch, forming the roof of the spinal canal.

Laminectomy: Surgical removal of the rear part of a vertebra in order to gain access to the spinal cord or nerve roots, to remove tumors, to treat injuries to the spine or to relieve pressure on a nerve root.

Laminotomy: An opening made in a lamina, to relieve pressure on the nerve roots. As opposed to laminectomy (where the entire lamina is removed), a laminotomy typically involves removal of just half the lamina (the side where a patient is having symptoms).

Lordosis: Lordotic curves refer to the inward curve of the lumbar spine. In some patients, this may represent a spinal deformity, also called swayback, which occurs when the lower back curves inward more than normal. Pathologic or excessive lordosis may be caused by osteoporosis or spondylolisthesis. Obesity, congenital disorders or overcompensation for kyphosis may contribute to this condition.

Medial facetectomy: A procedure in which a part of the facet is removed to increase space in the spinal canal.

Nerve roots: The initial portion of a spinal nerve; the nerve root is an extension of the central nervous system that begins at the spinal canal and ends in the extremities (fingers, toes). Its purpose is to send sensory information from the extremity to the brain and motor commands from the brain to the extremity.

Pedicle: The bony part of each side of the neural arch of a vertebra that connects the lamina (back part) with the vertebral body (front part).

Percutaneous: Effected, occurring or performed through the skin.

Pseudarthrosis: The movement of a bone at the location of a fracture or a fusion resulting from inadequate healing of the fracture or failure of the fusion to mature properly. This can also result from a developmental failure.

Scoliosis: Lateral (sideways) curvature of the spine. Spinal stenosis: Abnormal narrowing of the vertebral column that may result in pressure on the spinal cord, spinal sac or nerve roots arising from the spinal cord.

Spinous process: A slender projection of bone from the back of a vertebra to which muscles and ligaments are attached.

Spondylitis: Inflammation of vertebrae.

Spondylolisthesis: The forward displacement of one vertebra on another.

Spondylosis: Degenerative changes in the spine, most commonly affecting the intervertebral discs as well as the facet joints.