Medical/Neurosurgical Glossary
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Iatrogenic – Occurring without known cause. This is sometimes the result of a medical complication.

Iliac Bone – The bone tissue obtained from the ilium of the pelvis.

Iliac Crest – This is the large, prominent portion of the pelvic bone which is above the hip joint.

Iliolumbar Ligaments – These are fibrous bands from the ilium of the pelvis to the lower bones of the spine.  These hold the back erect. 

Ilium – A Latin word which describes one portion of the pelvis.  This bone provides attachments to many of the large muscles of the spine and the legs.

IME (Independent Medical-Legal Examination) - a medical-legal examination, performed by a physician, who is hired by a lawyer or insurance company; creates a report which can be used to settle a lawsuit or some workers' compensation cases.

Immobilization – A limitation of motion, or fixation of a body part, usually to promote healing.

Immobilization Syndrome– Bone loss and loss of function due to the limitation of motion, or fixation of a body part, from a cast for example.

Immune System – This is a complex network of specialized cells and organs which work together to defend the body against infections and tumors.

Impairment - a numeric percentage (from 1% to 100%) that reflects an injured worker's capacity; applies to the Federal system and some state systems, including some injuries in California occurring after 1/1/05.

Impingement Sign – A painful loss of range of motion of the shoulder in certain directions associated with certain shoulder injuries.

Inappropriate Secretion of Anti-diuretic Hormone – The opposite of diabetes insipidus, this is an uncommon disease where there is too much of a hormone called anti-diuretic hormone (ADH).  Too little urine is produced and the blood sodium can become dangerously low. 

Incision – The cutting into or removal of a small portion of a tissue or organ.  As differentiated from excision. 

Indemnity Plans – A type of health insurance that pays most doctor and hospital costs.  This type of insurance is often more expensive but provides the best coverage and the most choices.

Independent Medical-legal Examination (IME) – A report requested either a plaintiff attorney (representing a patient) or a defense attorney (representing an insurance company) in a personal injury dispute.

Incomplete – Less than 100% and not total.

Inferior – Situated below or underneath another structure.

Inflamed – Damaged and bruised, inflamed tissue is red, swollen, warm and painful.  Inflamed tissue is injured. 

Inflammation – The result of being inflamed or damaged marked by four signs: swelling, redness, heat, and pain.

Information and Assistance Officer - a California state official who is available to answer your questions.

Innate Intelligence – An alleged inborn ability of the body to heal itself, which chiropractors believe is enhanced by spinal adjustments.

Inpatient Surgery – A surgery which requires the patient to and stay in the hospital.

Internal Fixation – This is a way of repairing a broken bone, or securing a fusion, using metal parts which are entirely inside the body.  This is the opposite of external fixation. 

Inter – A Latin prefix that means between.

Intern – A doctor in training in the first year of practice after medical school.

Intermittent - under California law describes the frequency of a pain as occurring 50% of the time; of "occasional," "intermittent," "frequent," and "constant."

Interspinous – Refers to the space between the spinous processes of the vertebral bones. 

Interspinous Ligament – This is the fibrous ligament which extends from one spinous process (part of the back of a vertebral bone) to another.  These ligaments support the vertebral column. 

Intervertebral Disc – Intervertebral discs are soft tissue structures that are between the vertebral bones of the spine. They act as cushions but are easily damaged.

Intra – A Latin prefix that means that something is inside of something else.

Intra-Articular – Something which is within the joint.

Investigational New Drug – A drug allowed by the US Food and Drug Administration (FDA) to be used in clinical trials, but not approved for general sale to the public.

In vitro – This is Latin for “in glass.”  It describes experimental observations done in test tubes or similar laboratory vessels.

In vivo –In vivo is Latin for in life.  It describes experimental observations or other processes in a living body.

Irritable Bowel Syndrome – A painful abnormality of colon function which may be related to anxiety or may occur without other know abnormality.

Ischemia – Decreased flow of oxygenated blood to an organ due to obstruction in an artery.

Isometric –A muscle contraction without movement at the joint.  This is also one type of exercise where one tightens the muscles without moving the joints.

If you are aware of any useful spine and neuromusculoskeletal terms which are not included in this list, or if you have suggestions for better definitions,  your help would be greatly appreciated.  Please send me any upgrades and I will update the web site appropriately.  Click here to send a comment.