Lumbar fusion (arthrodesis) is a surgical technique in which two or more of the vertebrae in the spine are joined. They are fused in such a way that movement between them is prevented.
The concept of fusion is similar to what in mechanics is known as “welding”. However, vertebral fusion does not weld the vertebrae during surgery, but rather the bone grafts that are placed around the spine during surgery.
Bone grafts consolidate after several months (similar to the consolidation of a fracture), which joins or welds the vertebrae between them.

Indications for lumbar fusion

There are many potential reasons to consider merging the vertebrae. These include the treatment of fractures, correction of deformities, treatment of pain due to painful mobility, the treatment of instability and the treatment of some disc hernias in the lumbar or cervical spine.

-One of the reasons to perform a vertebral fusion is a spinal fracture: While not all spinal fractures need surgery, some fractures (especially those associated with neurological injury) require a fusion as part of the surgical treatment).
-Some types of spinal deformities such as scoliosis are often treated with vertebral fusion. The fusion is indicated for very important curves or the one that is getting worse.

You might also want to read: What is scoliosis?

-The displacement of one vertebra over the other (spondylolisthesis) can also be treated with vertebral arthrodesis (fusion).
-Another condition that may require vertebral fusion is the presence of instability. This refers to abnormal or excessive movement between two or more vertebrae, which can be a source of low back or neck pain, or cause irritation of adjacent nerves.
-Cervical hernias that need surgery generally require not only removing the herniated disc (discectomy), but also a fusion or disc replacement. With this procedure the disc is removed by an incision in the anterior part of the neck and a small bone fragment or implant is inserted instead of the disc.

The procedure

There are many surgical approaches and methods to fuse the spine, and most of them involve placing bone grafts or implants between the vertebrae.
The spine can be approached and the graft placed from behind (posterior approach) or in front (anterior approach), or by a combination of both.
In the neck, the anterior approach is more frequent; thoracic and lumbar fusion is usually done posteriorly.
The ultimate goal of the fusion is to obtain a solid bond between two or more vertebrae.
Fusion generally includes the use of instrumentation (plates, screws, cages or rods).
Instrumentation is sometimes used to correct a deformity. But is usually used as an “internal immobilizer” to keep the vertebrae still while the bone graft consolidates.

Bone graft

The bone graft to be used can be taken from a bone in the same patient (self graft) or bone bank (allograft). The bone taken from the same patient is the one that has the longest history. It has a predictable result and is the “gold standard” as a source of bone graft.
The allograft (bank bone) can be used as an alternative to the patient’s own bone. Although the consolidation of the allograft is not as predictable as the patient’s own bone, but avoids having to take grafting and therefore reduces the pain.
Currently, synthetic alternatives are also used as bone graft substitutes with good results.

At the London Spine Unit, we have some of the best specialist to perform lumbar fusion. Book an appointment to get a checkup.