Internal Fixation of the Lumbar Spine: Further Clinical Experience Using Computer Assisted Design and Manufacture of a Precise System

Abstract

Degenerative disorders of the lumbar spine cause loss of the normal disk space height, the formation of osteophytes, and facet joint osteoarthropathy, all of which singly or in combination cause encroachment upon the intraspinal and intraforaminal contents. This results in pain and neurologic dysfunction. The goals of therapy are restoration of normal function and prevention of further degenerative changes. Surgically, this is accomplished by enlargement of the spinal canal and intervertebral foramina (anatomical restoration) and prevention of further motion thus preventing further degenerative changes through fusion. Anatomic restoration of the caliber of the spinal canal and foramina may result in further instability of the spine also justifying fusion. For fusion to occur, a form of fixation or immobilization of the spine is necessary. The introduction of pedicle screw and dorsal plate fixation has provided us with a system permitting solid immobilization for patients undergoing fusion of the lumbar spine.