Silicon Valley Spine Institute

Glossary

POLYNEURITIS

Inflammation of two or more nerves simultaneously.

PORENCEPHALY

Abnormal cavity within brain tissue, usually resulting from outpouching of a lateral ventricle.

POST-ICTAL

State following a seizure, often characterized by altered function of the limbs and/or mentation.

POSTERIOR

The back of the body or situated nearer the back of the body.

POSTERIOR APPROACH

Used for laminectomies and spinal fusions at any level; Hibbs, Wagoner.

POSTERIOR CERVICAL SPINAL FUSION

Spinal fusion done from the back, using the lamina, facets, and spinous processes of the neck.

POSTERIOR FOSSA

The internal base of the skull.

POSTERIOR LUMBAR SPINAL FUSION

Spinal fusion done from the back using the lamina, the facets, and spinous processes of the lower back.

POSTERIOR NECK MUSCLES

Splenius, spinalis, and semispinalis.

POSTERIOR SPINAL FUSION

A fusion of the cervical, thoracic, or lumbar regions primarily fusing the lamina and sometimes the facet joints, using iliac or other bone graft.

POSTERIOR SPINAL MUSCLE SEGMENTS

Upper and lower posterior serratus m., spinalis m., semispinalis m., and rotators.

POSTEROLATERAL (P/L)

Behind and to one side, specifically to the outer side.

POSTEROLATERAL FUSION

A fusion of both the lamina and transverse process, using the iliac bone for graft, usually in the lower lumbar and first sacral segments.

POSTEROLATERAL INTERBODY FUSION (PLIF)

Lumbar spine fusion that involves an interbody fusion accomplished through the posterior approach.

POSTURE

The position of the limbs or the carriage of the body as a whole.

POTT d

Tuberculosis of the spine, usually in the lower thoracic segments.

POWERED SURGICAL INSTRUMENTS

Instruments which are powered by compressed air or electricity and are used in surgical procedures to cut, drill, or otherwise remove bone and cartilage, as well as to evacuate fluids.

PRE-CLINICAL STUDIES

Tests occurring prior to clinical studies, usually in vitro or in vivo involving animals. The purpose of these studies is to determine the safety and efficacy of the test material.

PREMARKET APPROVAL (PMA)

A regulatory method for gaining a marketing clearance from the FDA for a Class III medical device. A company submits information to the FDA that documents the safety and effectiveness of the device.

PREMARKET NOTIFICATION [510(k)]

A regulatory method for gaining clearance from the FDA to market a device. The FDA is petitioned by a company to determine if a particular medical device is substantially equivalent to a device which was commercially available prior to May 28, 1976. This method usually applies to Class I or II medical devices.

PRONATOR

A muscle which turns a part into the prone position.

PROPRIOCEPTION

Sensation concerning movements of joints and position of the body in space.

PROSTHESIS

An artificial body part such as an artificial leg or arm. The term prosthesis is also used to describe some of the implants used in the body such as a hip or knee replacement device.

PROTRUSION

Displaced nuclear material causes a discrete bulge in the annulus, but no material escapes through the annular fibers.

PROXIMAL

Nearest the center of the body.

PSEUDOARTHROSIS (also PSEUDARTHROSIS)

A form of non-union in which there is the formation of a false joint with some cartilage covering the ends of the bones and a cavity containing fluid that resembles a normal joint.

PSEUDOCLAUDUCATION

Increased pain and decreased strength in lower limbs associated with physical activity. Complaints are similar to those caused by insufficient blood supply to the limb but are caused by diminished blood supply to the nerves in a narrowed spinal canal.

PSEUDOTUMOR CEREBRI

Raised intracranial pressure, usually causing only headache and papilledema. No clear underlying structural abnormality.

PUPIL

The black part of the eye through which light enters; enlarges in dim light and decreases in size in bright light.

PYRAMIDAL TRACT

Carries the voluntary muscle messages from the brain.