Glossary items beginning with D (10).
Decompensation - In scoliosis, this refers to loss of spinal balance when the thoracic cage is not centered over the pelvis.
Decompression - To relieve pressure on the spinal cord or nerve roots. The pressure may result from bone (the lamina, pedicles, vertebral body), fractured bone fragments, disc herniation, ligaments, bone spurs, tumor, infection, or abnormal curvature of the spine (scoliosis or kyphosis).
Disc Degeneration - The loss of the fluid content, structure and functional integrity of the disc.
Disc Herniation - The tear of the firm, fibrous tissue called the annulus with rupture of the soft, gelatinous inter-vertebral disc through the outer aspect of the disk. Extrusion, implies that the fragment of disc material that is not attached to the annulus and may move up or down from the site of herniation; sometimes it has passed through a hole in the posterior longitudinal ligament. The term herniated nucleus pulposus (HNP) is a catchall phrase for all of these conditions.
Discectomy - Removal of all or part of an intervertebral disc (the soft tissue that acts as a shock absorber between the vertebral bodies). This may be done for fusion or because of herniation.
Distal - Situated away from or farther from a point of reference; opposite of proximal
Double curve - Two lateral curvatures (scoliosis) in the same spine.
Double major curve - Describes a scoliosis in which there are two structural curves which are usually of equal size.
Double thoracic curve - A scoliosis with a structural upper thoracic curve, as well as a larger, more deforming lower thoracic curve and a relatively non-structural lumbar curve.
Dura - The 3 layer membrane which contains the spinal cord and spinal fluid. It can be torn or stretched during spinal surgery. It can often be repaired nor patched with fascia or allograft dura.