Annulus fibrosis - tough fibrous ring around the disc.

Anterior - From the front of the body.

Anterior Column - the front 3/4 of the vertebral body and disc (as defined by a study by Denis). The column classification is used to determine the stability of the spine.

Autogenous Bone - bone originating from the same individual; i.e., a patient's own bone.

Autograft Bone - bone transplanted from one part to another part of the body in the same individual.

Bone Morphogenic Protein (BMP) - naturally occurring chemicals in the body- that play a major role in bone growth. BMP-like products are proteins that enhance mineralization and which can increase bone formation during fusion operation.

Bone spurs - also called osteophytes.

Bulge of the disc: the form or position of the disc changes with some slight impingement into the spinal canal. Also called a prolapse or protrusion.

Cervical - Referring to the neck, the top seven vertebrae of the spine.

Corpectomy - Removal of the vertebral body, usually to remove pressure off of the spinal nerves.

Degeneration of the disc: chemical changes associated with aging causes discs to weaken, but without a herniation. These changes can be seen on MRI scans, and are usually asymptomatic.

Diagnostic tests - include MRI, X-ray, CT scan, bone scan, discogram, myelogram.

Disc (also spelled Disk) - the structure between the vertebral bodies.

Discectomy - removal of the disc.

Extrusion of the disc: the gel-like nucleus pulposus breaks through the tire-like wall (annulus fibrosus) but remains within the disc.

Foraminotomy - opening of the foramen where the nerve exits.

Kyphosis - roundback (when viewed from the side). The thoracic spine is normally kyphotic.

Laminectomy - removal of the lamina.

Laminotomy - partial removal of the lamina.

Lordosis - swayback (when viewed from the side). The cervical and lumbar spines are normally lordotic.

Middle Column - the posterior portion of the vertebral body and disc (as defined by a study by Denis). The column classification is used to determine the stability of the spine.

Myelopathy - spinal cord dysfunction usually caused by compression. Signs include hyperreflexia (heightened reflexes), balance difficulties, dropping items and lack of coordination, and bowel and bladder dysfunction.

Natural History - what the patient's outcome would be in given disease or condition without intervention (naturally).

Nucleus Pulposus - the soft inner core of the disc.

Neuroforamina - the tunnels where the nerve exists from the spinal canal to the arms and legs.

Osteophyte - bone spur.

Pars Interarticularis - a posterior bony structure between two adjacent facet joints in the lumbar spine. This structure is stressed and may fracture with extension and rotation of the lumbar spine.

Postlaminectomy spondylolisthesis - a slipped vertebral body which occurs post-operatively, if the remaining bones are not strong enough to support the spine.

Posterior - from the back of the body.

Posterior Column - the facet joint, lamina, pars, spinous process, and adjoining ligaments. The column classification is used to determine the stability of the spine.

Posterior Longitudinal Ligament - ligament between the vertebral body and discs in front, and the spinal cord or nerve sac in back.

Prolapse of the disc: the form or position of the disc changes with some slight impingement into the spinal canal. Also called a bulge or protrusion.

Protrusion of the disc: the form or position of the disc changes with some slight impingement into the spinal canal. Also called a prolapse or bulge.

Pseudoarthrosis - lack or failure of fusion.

Radiculopathy - arm or leg pain being caused by nerve impingement or irritation.

Radicular - pain radiating down the arms or legs.

Scoliosis - curvature of the spine when viewed from the front or back. The curvature is usually associated with rotation of the vertebral bodies.

Sequestration or Sequestered Disc: the nucleus pulposus breaks through the annulus fibrosus and lies outside the disc in the spinal canal (HNP).

Stenosis - tightness and compression of the spinal cord, nerve roots, or dural sac.

Strut graft - A long piece of bone or cage that is inserted into the space created by corpectomy to support (struts) the anterior column of the spine.

Spondylolisthesis - the slipping of one vertebra onto another.

Spondylolysis - a defect in the pars interarticularis.