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LABYRINTH
The internal ear, comprising the semi-circular canals, vestibule and cochlea.

LAMINA
The flattened or arched part of the vertebral arch, forming the roof of the spinal canal. The posterior part of the spinal ring that covers the spinal cord or nerves.

LAMINECTOMY
Excision of one or more laminae of the vertebrae. Removal of the lamina, the bony element covering the posterior portion of the spinal canal.

LAMINOPLASTY
The lamina are hinged laterally opened like a door, and secured in their new position with suture or bone to enlarge the spinal canal.

LAMINOTOMY
An opening made in a lamina. Formation of a hole in the lamina without disrupting the continuity of the entire lamina to approach the intervertebral disc or neural structures.

LAPAROSCOPY
A form of minimally invasive surgery using a type of endoscope known as a laproscope. The technique allows surgeons to perform procedures without making major incisions that can lead to long recovery times.

LASER
Light Amplification by Stimulated Emission of Radiation. The device that produces a focused beam of light at a defined wavelength that can vaporize tissue. In surgery, lasers can be used to operate on small areas without damaging delicate surrounding tissue.

LATERAL
Situated away from the midline of the body.

LATERAL MASS
The lateral expansion of the spinal ring in the cervical spine, consisting of the facet joints and intervening bone as well as a tunnel through which the vertebral artery travels in the second through fifth cervical vertebra.

LEEDS
For scoliosis, segmental wiring of a contoured square-ended Harrington rod.

LEPTOMENINGES
Two thin layers of fine tissue covering the brain and spinal cord (The pia mater and arachnoid).

LEPTOMENINGITIS
Inflammation of the membranes covering the brain and spinal cord.

LEPTOMENINGOPATHY
Disease of the arachnoid or pia matter of the brain and spinal cord.

LEUKODYSTROPHY
Disturbance of the white matter of the brain.

LEUKOENCEPHALITIS
An inflammation of the white matter of the brain.

LIGAMENT
A band of flexible, fibrous connective tissue that is attached at the end of a bone near a joint. The main function of a ligament is to attach bones to one another, to provide stability of a joint, and to prevent or limit some joint motion.

LIGAMENTOUS
Relating to or of the form or structure of a ligament.

LIGAMENTUM FLAVUM
A band of yellow elastic tissue that runs between the laminae from the axis to the sacrum; it assists in maintaining or regaining erect position and serves to close in the spaces between the arches.

LIMBUS ANNULARE
A mass of bone situated at the anterospuerior margin of a vertebra. Arises from failure of fusion of the primary and secondary ossification centers.

LINEAR ACCELERATOR
Equipment that precisely delivers a concentrated dose of radiation to a predetermined target using x-rays.

LIPOMA
A benign fatty tumor, usually composed of mature fat cells.

LOCALIO
For sacral tumor; a method for partial excision of the scarum.

LOCALIZATION
Limitation to a definite area. The reference of a sensation to its point of origin.

LONG BEACH PEDICLE SCREW
Posterolateral fusion screw and rod device.

LONGISSIMUS COLLI
Long muscle immediately anterior to the cervical spine.

LONG TRACTS
The nerve fibers that connect the voluntray muscle messages from the brain.

LORDOSCOLIOSIS
Lateral curvature of the spine associated with backward bending of the spine.

LORDOSIS
Curvature of the spine with the convexity forward. Not a disease state, but the normal anterior concavity of the neck or low back.

LOUGHHEED and WHITE
For drainage of lower abdominal abcess; coccygectomy and drainage from space anterior to sacrum.

LUMBAGO
A non-medical term signifying pain in the lumbar region. Archaic term meaning back pain.

LUMBAR
The lower part of the spine between the thoracic region and the sacrum. The lumbar spine consists of five vertebrae. The five moveable spinal segments of the lower back and largestof the spinal segments.

LUMBAR CURVE
Curve with apex between the first and the fourth lumbar vertebrae.

LUMBAR DRAIN
A device (usually a long, thin, flexible tube) inserted through the skin into the cerebrospinal fluid space of the lower back; provides a method of draining cerebrospinal fluid.

LUMBARIZATION
Partial or complete formation of a free-moving first sacral segment so that it looks like a lumbar vertebra.

LUMBAR KYPHOSIS
Reverse of the normal curve of the low back.

LUMBAR LORDOSIS
Angle made by lines drawn from the superior surface of the first and fifth lumbar vertebra.

LUMBAR MICRODISCECTOMY
An operation on the lumbar spine performed using a surgical microscope and microsurgical techniques.

LUMBOSACRAL CURVE
A lateral curve with its aspect at or between the fifth lumbar vertebra.

LUMBOSACRAL JOINT ANGLE
Angle between the inferior surface of the fifth lumbar vertebra and the top of the sacrum.

LUQUE INSTRUMENTATION
A posterior method of fixation.

LUQUE ISF
For posterolateral fusion fixation; a pedicle screw and plate device.

LUXATION
Dislocation.