WHAT’S A SPINAL FUSION?
The term “Spinal Fusion” refers to a neurosurgical procedure that joins two or more vertebrae permanently into one solid bone 1. This fusion leaves no space between these two or more bones. Spinal fusion uses an extra bone to fill the space that usually develops between the two separate vertebrae. When the bone heals, there’s no longer space between them. Neurosurgeons can perform this fusion at any level of the spine. This helps to prevent any movement between the fused vertebrae. This procedure, sometimes, known as a welding process due to it turning two or more vertebrae into a single, solid bone.
Spinal fusion helps to eliminate painful motion and helps to restore the stability of the spine. According to a report by the Agency for Healthcare Research and Quality (AHRQ), neurosurgeons performed almost 488,000 spinal fusions in the USA in 2011. Neurosurgeons usually recommend spinal fusion surgery after when they can identify the source of the pain by performing several imaging tests such as X rays, computerized tomography (CT) scans, and magnetic resonance imaging (MRI) scans.
Conditions for Spinal Fusion
Neurosurgeons will likely not recommend doing spinal fusion in patients with the following conditions:
- Patients with problems that might prevent bone fusion
- Patients who undergo prior abdominal surgery
- Patients with the problem of atherosclerosis in the aorta or iliac vessels
- Patients with obesity and severe osteoporosis
An ideal candidate most likely has a diagnosis of herniated discs, spinal stenosis, spinal deformities, spinal tumor, degenerative disc disease, or pain caused by several reasons. Neurosurgeons also recommend spinal fusion for the patients who have the followings 2:
- Spinal instability
- Spondylolisthesis
- Scoliosis
- Lordosis
- Spondylosis
- Spinal weakness
- Discogenic pain
- Vertebral fracture
- Kyphosis
- Posterior rami syndrome, etc.
Patients who have already undergone several conservative treatments can try spinal fusion. This helps to improve the spinal movement and reduce the pain level. The neurosurgeon will explain the benefit and risk of this operation before performing this operation.
Different Types of Spinal Fusion
Several types of spinal fusion surgery available for the patients. The most common spinal fusion techniques include 3:
- Posterolateral gutter fusion: This procedure performs through the back.
- Posterior lumbar interbody fusion (PLIF): Neurosurgeons operate the procedure from the back and removes the disc between two vertebrae. Then they insert bone into the space created between the two vertebrae.
- Anterior lumbar interbody fusion (ALIF): Neurosurgeons perform the technique from the front and removes the disc between two vertebrae. Finally, they insert the bone into the space created between the two vertebrae.
- Anterior/posterior spinal fusion: Neurosurgeons operates this process from the front and the back
- Transforaminal lumbar interbody fusion (TLIF): Just similar to the PLIF, neurosurgeons perform this procedure from the back of the spine.
- Extreme Lateral Interbody Fusion (XLIF): Also known as an interbody fusion where neurosurgeons make their approach from the side.
Risks of Spinal Fusion
During any surgical operation, complications may occur. Complications of spinal fusion surgery can remain serious, including death. A higher risk of complications usually seen in older people with higher body mass index (BMI), other medical problems, poor nutrition, etc. Potential complications include 4:
- Infection at the surgical site
- Delay wound healing
- Excessive loss of blood
- Insertion of spinal hardware
- Formation of blood clot or hematoma
- Injury to the blood vessels or spinal nerves
- Harvesting of bone graft, etc.
How should a patient prepare for a Spinal Fusion procedure?
Preparation of spinal fusion procedure requires trimming the hair of the patients over the surgical site and cleaning the area with antiseptics. Also, the surgical team will monitor and evaluate any harmful bacteria by taking the patient’s nasal swab sample prior to the surgery. Patients need to stop drinking or eating any foods at least 12 hours before the surgery. Patients need to discuss the medication that they took and neurosurgeons will ask to stop taking some medications such as blood thinner before the surgery.
How does a Spinal Surgeon perform Spinal Fusion?
Spinal fusion procedure requires an expert surgical team led by an expert neurosurgeon with a vascular surgeon, an anesthesiologist, and nurses to perform successfully. The entire operation may require as long as 6 to 7 hours to complete. The basic steps include 5:
- Patients need to lie on their stomachs on the operating table.
- Anesthesiologists will administer general anesthesia to the patient to fall asleep so that patient may not feel any sensation.
- Nurses will prepare the incision site and monitor the vital signs of the patient’s body such as heart rate, respiration, etc.
- Neurosurgeons will prepare the bone graft that will use to fuse two vertebrae.
- Depending on the location, neurosurgeons will make a small incision in the cervical area or abdomen to get a clear view of the spine by retracting the muscles and other structures.
- Neurosurgeons will remove the bone spurs from the affected vertebral space and insert the bone graft into the space between the vertebral bodies.
- This bone graft helps to support the disc space and promote bone healing into a solid bone.
- Finally, surgeons will put back the structures such as muscles and tissues to their normal place and suture the skin together.
How long does a Spinal Fusion procedure typically take?
The spinal fusion surgery can take as little as 2 hours and as long as 6 or 7 hours or even more. The duration of the operation depends upon the number of vertebrae remaining fused and the condition of the vertebrae. Complications during the operation can make the condition worse and take more time, eventually.
What does recovery from Spinal Fusion look like?
Recovery from a spinal fusion surgery depends upon the type of procedure performed. Usually, patients require about 3.7 days of hospital stay after the surgery. Some patients can return home on the same day after surgery if they undergo a simple cervical spinal fusion at the hospital. Minimally invasive surgeries help to reduce the time spent at the hospital. Recovery of the patient usually involves avoiding certain activities and rehabilitation training. Most people can walk the day after surgery and can sit at 1–6 weeks following surgery.
References
- Dhillon KS. Spinal Fusion for Chronic Low Back Pain: A ‘Magic Bullet’ or Wishful Thinking? Malaysian Orthop. J. 10, 61–68 (2016).
- Rushton, A. et al. Patient journey following lumbar spinal fusion surgery (FuJourn): A multicentre exploration of the immediate post-operative period using qualitative patient diaries. PLoS One 15, 1–19 (2020).
- Harris, I. A., Traeger, A., Stanford, R., Maher, C. G. & Buchbinder, R. Lumbar spine fusion: what is the evidence? Intern. Med. J. 48, 1430–1434 (2018).
- Mino, D. E., Munterich, J. E. & Castel, L. D. Lumbar fusion surgery for degenerative conditions is associated with significant resource and narcotic use 2 years postoperatively in the commercially insured: a medical and pharmacy claims study. J. Spine Surg. 3, 141–148 (2017).
- Yavin, D. et al. Lumbar fusion for degenerative disease: A systematic review and meta-analysis. Clin. Neurosurg.80, 701–715 (2017).