Spinal Fusion

Spinal fusion, otherwise referred to as vertebral arthrodesis, is a medical operation that has the purpose of permanently linking together two or more vertebrae and thus rendering them motionless. The main goals of spinal fusion are to stabilize the spine, alleviate pain, and avoid the further deterioration of the nervous system. The joining of the vertebrae is done through the insertion of bone graft material in between them, which is sometimes made stronger with the use of various hardware such as screws, rods, or cages

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The normal functioning of the spine is characterized by the interplay between its mobility and stability. Pathological conditions such as degenerative changes, trauma, deformity and instability can lead to loss of balance and hence cause pain or nerve compression. Fusion is most appropriate when there is a clear indication of abnormal motion between the vertebrae as a cause of the patient's symptoms.

Most common medical reasons for performing a spinal fusion are: degenerative disc disease that did not respond to conservative treatment, spondylolisthesis, spinal curvatures like scoliosis and kyphosis, vertebral fractures, tumors in the spine, and infections that need the support of stabilization. It is believed that there will be a number of statutes in favor of surgeries where the exact problem is structural rather than cases of nonspecific chronic low back pain.

Various surgical methods have been developed, including posterior lumbar interbody fusion (PLIF), anterior lumbar interbody fusion (ALIF), lateral approaches, and posterolateral fusion. One of the goals of the advances in minimally invasive techniques is to bring about less damage to the tissues, lower blood loss, and reduce the time needed for recovery while keeping the fusion rates equal. The use of instrumentation is very common in the procedures to provide immediate stability and thereby increase the chances of successful fusion.

The clinical results depend on the indications. Fusion has proven to be advantageous in cases like spondylolisthesis and spinal deformity. Still, systematic reviews have given only limited support that fusion yields better outcomes with non-operative treatment or decompression alone in degenerative lumbar cases without instability. Therefore, patient selection plays an important role.

Spinal fusion is accompanied by risks, some of which are infection, bleeding, nerve injury, nonunion (failed fusion), and adjacent segment disease, which happens when increased mechanical stress leads to the degeneration of the neighbouring spinal segments more quickly. Elderly patients and those with other health problems are more likely to suffer from complications.

To sum up, surgical spinal fusion is an intervention of high value for the patients with structural spinal pathology who have been selected carefully. It is effective in some cases, but its use in degenerative back pain without instability still remains a controversial issue. Research and technological advancements are an unending process that continues to improve the indications, techniques, and outcomes.

Written by Aniket Kumar Sinha at Incisionary

References:

American Academy of Orthopaedic Surgeons. (n.d.). Spinal fusion. OrthoInfo.https://orthoinfo.aaos.org/en/treatment/spinal-fusion

Cleveland Clinic. (n.d.). Spinal fusion: What it is, risks & recovery.https://my.clevelandclinic.org/health/treatments/25168-spinal-fusion

Försth, P., Ólafsson, G., Carlsson, T., Frost, A., Borgström, F., Fritzell, P., Ohagen, P., & Michaëlsson, K. (2016). A randomized, controlled trial of fusion surgery for lumbar spinal stenosis. The New England Journal of Medicine, 374(15), 1413–1423.https://www.nejm.org/doi/full/10.1056/NEJMoa1513721

Gibson, J. N. A., & Waddell, G. (2005). Surgery for degenerative lumbar spondylosis. Cochrane Database of Systematic Reviews, (4), CD001352.https://doi.org/10.1002/14651858.CD001352.pub3

Mayo Clinic. (2023). Spinal fusion.https://www.mayoclinic.org/tests-procedures/spinal-fusion/details/what-you-can-expect/rec-20155761

Mobbs, R. J., Phan, K., Malham, G., Seex, K., Rao, P. J., & Johnson, R. D. (2015). Lumbar interbody fusion: Techniques, indications, and comparison of interbody fusion options including PLIF, TLIF, OLIF/ATP, LLIF, and ALIF. Journal of Spine Surgery, 1(1), 2–18.https://jss.amegroups.org/article/view/3512

National Library of Medicine. (n.d.). Spinal fusion. MedlinePlus.https://medlineplus.gov/ency/article/002968.htm