Scoliosis Research Society (SRS)
An International Organization Dedicated to the Education, Research and Treatment of Spinal Deformity
Our Mission is to Foster Optimal Care for All Patients with Spinal Deformities
Glossary items beginning with I (6).
Idiopathic scoliosis - A structural spinal curvature for which the cause has not been established. There is no evidence of underlying physical or radiographic pathology. The most common type of scoliosis.
Iliac Bone - A part of the pelvic bone that is above the hip joint and from which autogenous bone grafts are frequently obtained.
Inclinometer - An instrument used to measure the angle of thoracic (rib) or lumbar (flank) prominence, referred to as the angle of trunk rotation (ATR).
Infantile scoliosis - A curvature of the spine that develops before three years of age.
Internal Fixation - The immobilization of bone fragments or joints with implants (metal screws, rods, etc.) in order to promote healing or fusion.
Interspinal or intervertebral disc - The structure that normally occupies the space between two moving vertebrae. It is more prominent in the cervical and lumbar spines. It is much like a radial tire. The centermost portion of the disc (nucleus pulposus) is normally composed of a clear gelatinous material that varies in consistency from a firm jelly material to a very thick and less pliable substance. This core is then surrounded by numerous layers of fibrous (fibrocartilaginous) material called the annulus fibrosus. That structure goes to the normal margins of the vertebral body. There is a thick ligament (approximately 2mm) that covers the anterior part of the vertebral body called the anterior longitudinal ligament, and on the spinal canal side posteriorly is the posterior longitudinal ligament.