Spinal fusion, also known as arthrodesis, is a surgical technique which involves the union of two or more vertebrae in the spine. Lumbar fusion refers to the surgical union of the vertebrae in the lumbar region i.e. lower back. Lumbar fusion is performed to relieve pain, restore the neuronal functions and prevent abnormal movement in the spine.
Lumbar fusion surgery may be employed for the management of various conditions such as spondylolisthesis (gliding of the spine bones), scoliosis or kyphosis (anomalous curvature of the spine), degenerated discs, repeated disc herniation, spinal infections or tumors, traumatic injury to the spine, and spine instability.
Based on the location of the surgery and placement of the bone graft, spine fusion surgery can be categorized as:
- Posterolateral gutter fusion: this procedure is performed through the back
- Posterior lumbar interbody fusion (PLIF/TLIF): this procedure is also performed through the back and involves the removal of the intervertebral disc and insertion of a bone graft in the space created
- Anterior lumbar interbody fusion (ALIF): this procedure is performed from the front and involves the removal of the intervertebral disc and insertion of a bone graft in the space created
- Anterior/posterior spinal fusion: the procedure is also performed from the front as well as the back
Lumbar fusion can be performed either from the front (anterior) or the back (posterior). In the anterior approach, the disc and surrounding arthritic area is removed by the surgeon. A bone graft is then placed between the vertebrae, which helps in the fusion of the adjoining vertebrae responsible for the abnormal motion of the spine. In the posterior approach, the bone graft is placed on the sides of the vertebrae to fuse them and prevent abnormal motion.
Based on the source of the bone graft, it can be categorized as either an autograft or an allograft. Autograft refers to a bone graft taken from a different bone of the same patient, whereas an allograft is obtained from a bone bank. Metal rods, plates and screws, referred to as instrumentation, are also used along with the bone graft to stabilize the spine.
Post operative care
Patients may be discharged home after 1-4 days of the surgery. Some of the post-operative instructions after a lumbar fusion surgery include:
- Back braces
- Avoid uncomfortable movements such as twisting and bending
- Adequate rest
- Keep the incisions clean and dry
- Avoid heavy work
Risks and complications
The risks and complications associated with lumbar fusion surgery include infection, nerve damage, loss of sensation, bladder or bowel dysfunction, implant dislocation, pain at the site of bone graft, and pseudarthrosis.