CHAPTER 20
LUMBAR FUSIO� ( PLIF , TLIF , POSTERO LATERAL FUSIO� A�D I�TERSPI�OUS DEVICES )
( This is the section that explains the detail of the operation or procedure above and should be read in conjunction with the chapter Your Back Operation ).
Sometimes it is necessary to perform a lumbar spinal fusion . This is done to create a bony union between two or more lumbar vertebrae , in order to stabilise the spine . It is usually done for instability which may arise from an injury or from wear and tear changes . It may also be secondary to extensive decompressive surgery or may be made necessary by a gradual dislocation from an inborn abnormality . Other causes are infection , tumour or a previous fusion that has failed to unite .
A spinal fusion operation is also sometimes performed following lumbar disc removal , nerve decompression , removal of vertebral bodies or for the correction of spinal deformity .
In order to improve the chances of successful bony union , internal supports and pedicle screws are often used ( see the chapter Anatomy of the Spine ). Internal devices may consist of blocks of bone , plastic or metal , which are introduced between the vertebrae . Instrumentation consists usually of pedicle screws with rigid linkages . These pedicle screws pass through the pedicles of the vertebrae and achieve a strong hold on the vertebrae . They are then interconnected with a rod .
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