Lumbar spinal fusion

Also known as spondylodesis or spondylosyndesis.

A spine fusion is a surgery performed to link together individual segments, or vertebrae, within the spine.

Intended to stop the motion at a painful vertebral segment, which in turn should decrease pain generated from the joint.

Multiple approaches to lumbar spinal fusion surgery, and involve adding bone graft to an area of the spine to set up a biological response that causes the bone graft to grow between the two vertebral elements and create a fusion.

Considered if abnormal and excessive motion at a vertebral segment results in severe pain and may be due to degenerative disc disease, degenerative or postlaminectomy spondylolisthesis, isthmic spondylolisthesis, unstable spine from malignancy, infection, fractures, scoliosis or other deformities.

Two vertebral segments need to be fused together to stop the motion at one segment.

A spine fusion surgery involves using bone graft to cause two vertebral bodies to grow together into one long bone, and the graft can be taken from the patient’s hip during the spine fusion surgery, harvested from cadaver bone or manufactured, or synthetic bone graft substitute.

Spinal fusion of more than two segments is unlikely to provide pain relief because it removes too much of the normal motion in the lower back and places too much stress across the remaining joints.

There are two main types of lumbar spinal fusion, which may be used in conjunction with each other.

Posterolateral fusion places the bone graft between the transverse processes in the back of the spine.

With posterolateral fusion the vertebrae are fixed in place with screws and/or wire through the pedicles of each vertebra attaching to a metal rod on each side of the vertebrae.

Interbody fusion places the bone graft between the vertebra in the area usually occupied by the intervertebral disc and the later is removed entirely.

In the Interbody fusion a device, either platic or titanium, may be placed between the vertebra to maintain spine alignment and disc height.

In the Interbody fusion, the fusion occurs between the endplates of the vertebrae.

When both types of fusion are used it is known as 360-degree fusion.

Interbody fusion has higher fusion rates than the posteriorlateral fusion.

Three types of interbody fusion are the Anterior lumbar interbody fusion whereby the disc is accessed from an anterior abdominal incision, the Posterior lumbar interbody fusion where the disc is accessed from a posterior incision, and the Transforaminal lumbar interbody fusion where the disc is accessed from a posterior incision on one side of the spine.

As part of the process to perform spine fusion instrumentation, the placing of metal within the spine to hold the vertebral bones together may be performed.

Spinal instrumentation utilization depends on many factors including the underlying problem being treated, the age of the patient, and the number of levels of the spine being fused.