Home > Procedures > Spinal Surgery > Spinal Fusion

Spinal fusion is a surgery performed to permanently fuse two or more vertebrae of the spine. Below you’ll find useful information about this type of surgery including why it is performed, how it is performed and the outcomes of surgery for the patient.

The spinal fusion procedure consists of techniques that resembles the process of healing of the fractured bones. During the surgical process of spinal fusion, the surgeon inserts a bone or bone-like material in the space between the two adjacent vertebrae. The materials used to hold the vertebrae in place together include metals rods, and screws. These are placed in such a manner that the healing happens as one solid unit. 

The spinal fusion surgery changes the normal functions and motion of the spine as it may restrict some parts of the movement. The extent of movement restriction depends on the site and the number of levels of vertebrae that may be fused. This may result in an extra strain and stress on vertebrae around the connected portions of the spinal cord and might increase the degeneration rate adjacent to the fused areas of the spine. 

Why or when is it usually performed? 

The procedure of spinal fusion provides support to the spinal cord, decrease the pain and fix a deformity by fusing two or more vertebrae permanently. The doctor will advise a spinal fusion surgery to treat various spine problems, as mentioned below.

Spinal deformities

Spinal fusion surgery assists in treating many spinal deformities. These can include scoliosis (sideways curvature of the spinal cord), spinal stenosis (narrowing of the spinal canal), spine infections or tumours, or kyphosis (abnormal rounding of the upper part of the spine).  

Broken vertebrae

It is not mandatory to go for spinal fusion for any broken vertebrae as many such cases heal on their own. The doctor advises the spinal fusion only if the breakage in the vertebrae makes the spinal cord unstable. 


Spondylolisthesis is a spinal cord disorder in which one vertebrae slips onto the vertebrae below it. This decreases the space between the two adjacent vertebrae. In such a situation, the doctor advises spinal fusion to correct spondylolisthesis especially in case of the symptoms such as chronic backache or nerve crowding, which may cause numbness or pain in the leg. 

Spinal instability or weakness

In some cases, the spinal cord may become unstable if there is excessive or abnormal movement between the two vertebrae. This is usually a common symptom of chronic arthritis of the spine. The doctor may suggest spinal fusion to help regain the stability of the spinal cord. 

Severe lower backache

Spinal fusion surgery may be offered to a small percentage of patients that have been diagnosed with discogenic low back pain. Surgery becomes an option if they do not respond to conservative trial of treatment.

Herniated disk

In some cases, the spinal fusion is performed to provide stability to the spine after the removal of a damaged or herniated disk. This is usually offered to patients who have multiple recurrences of disc prolapse despite having microdiscectomy.

Types of spinal fusion

Cervical Spine

In the cervical spine the option of fusion surgery is mainly the anterior cervical discectomy (ACDF) and fusion . In some cases the whole vertebra has to be removed to take the pressure off the spinal cord. This is called a vertebrectomy and fusion.

Both the ACDF and the vertebrectomy may be further stabilised by supplementing them with posterior cervical screws and fixation. 

Lumbar Spine

There can be multiple types of spinal fusion surgeries for the lumbar spine. They are named based on the way the lumbar spine is accessed.

  • Transforaminal lumbar interbody fusion (TLIF)
  • Oblique lumbar interbody fusion (OLIF)
  • Posterior lumbar interbody fusion (PLIF)
  • Anterior lumbar interbody fusion (ALIF)
  • Lateral lumbar interbody fusion (LLIF)

How to prepare for surgery?

The doctor will take a complete medical history of the patient. He or she will ask the patient about all the existing or past medical conditions, allergies, any bleeding disorders, or surgeries. 

The patient is also asked to go through some blood tests and X-rays scans. This is to access the affected area and to examine the damaged part of the spine.

Patients may have to undergo specialised scans if they need to have robotic spine surgery or navigation guided spine surgery. 

The patient is advised to communicate to the doctor if they are taking any blood thinning medications or any supplements. The doctor will assess whether to continue with or to stop the medications.

The patient is advised not to smoke as it delays the healing process after the treatment. The patient is also suggested to avoid alcohol.

The patient is also advised not to eat or drink in the night before the day of surgery.

How is the procedure performed?

Spinal fusion generally involves the following steps:

Disc space preparation

The surgeon makes an incision to reach the vertebrae to be fused. In the cervical spine, the incision is made directly in the back or in the throat or abdomen so the surgeon can easily access the spine from the front side. The surgeon moves away the muscles and the blood vessels, which come in the way of the vertebrae to be treated.

In the lumbar spine, the site of the incision depends on the planned type of lumbar fusion. Depending on which, the incision can be over the abdomen and pelvis, over the flank or in the posterior part of the spine. 

Preparation of the bone graft

The bone, which is used to connect or fuse the two vertebrae is either taken from the bone bank or the body of the patient (mostly pelvis). If taken from the patient’s pelvic part, then the incision is made over the pelvis and the required amount of bone is taken, after which the incision is closed.

Spine Fusion

The surgeon then places the bone graft in between the two vertebrae to be fused. The materials used to hold the vertebrae in place are inserted using minimally invasive spine surgery techniques. With keyhole spine surgery, the surgeons use state of the art technologies such as the Mazor robot or spine navigation using Brainlab.

What are the risks and possible side effects associated with this procedure?

Some of the risks associated with the spinal fusion procedure include:

  • Severe pain
  • Uncontrolled bleeding
  • Tenderness
  • Infections in the vertebral bones or the surgical site.
  • Swelling
  • Injury to the surrounding blood vessels or nerves, which may result in numbness or weakness
  • Leakage of spinal fluid

The recovery from surgery

The patient may experience some pain post-surgery. This usually depends upon the duration and the site of the surgery. However, the doctors will prescribe painkillers or anti inflammatory drugs to reduce and control the pain.

The patient should call the doctor immediately if any of the following signs are observed, after going home:

  • Severe weakness
  • Swelling, bruising or bleeding from the treated site
  • Severe pain or discomfort in the area treated
  • Shaking chills
  • Any signs like fever (more than 100.4 F) or 38°C, drainage or redness
  • Difficulty in breathing
  • Some patients might face irritability or severe itching on the operated site (near sutures)
  • Any new tingling or numbness observed

The complete recovery may take several months for the bones to fuse properly and heal after the surgery. The doctors may advise some patients to wear a brace initially, to stabilise the spinal cord and keep it properly aligned.

The doctors may also suggest a physical rehabilitation program. This can consist of education, exercises, and counselling. These programs assist the patient to walk, sit and stand properly so that the spinal cord is correctly aligned.

Success rates and how long effects last

Spinal fusion surgeries are very successful. Based on multiple studies, the success rate of spinal surgeries is pegged between 70%-90%. The patient might need 3-6 months, before the results from the surgery are completely visible. The results from the procedure are long lasting though and the patient might not need a follow up treatment after the procedure.

Frequently asked questions

Will the patient be able to bend or perform daily activities, after the spinal fusion surgery?

The spinal vertebrae, fused during the surgery, may not be able to move as freely, as they they used to originally. The surgery may cause some loss of motion. The person is usually able to perform the normal routine activities and play some sports as well. However, the fusion of the vertebrae may create some hindrances. The patient should consult the doctor after the surgery and understand the activities, which the patient should avoid.

What are the factors the adversely affect spine fusion? 

Factors that affect spine fusion, include the following:

  • Obesity
  • Smoking (nicotine)
  • Osteoporosis
  • Diabetes Mellitus or other chronic illnesses
  • Chronic steroid use
  • Prior back surgery or attempted fusion
  • Post-surgery activities
  • Malnutrition

Does osteoporosis or reduced bone density affect spine fusion? 

Patients suffering from osteoporosis may need a long time in a spinal brace to accomplish the same outcome. Patients with osteoporosis also have reported to have lower bone fusion or healing rates and problems at spinal levels following the surgery levels. 

Are there any long term side effects to spine fusion? 

Yes, following are the two types of long-term side effects to spine fusion:

  • Failure of the procedure itself (failed fusion)
  • Complications arising as a result of the fusion such as hardware breaking, hardware becoming loose, spine muscle injury, and Adjacent Segment Disease.

How long does it take before one can return to doing a desk based job? 

If the patient has a desk-based job, then it is advised to arrange at least four weeks off work post-surgery. This will allow the proper recovery and help the patient manage symptoms of pain and fatigue.

How does smoking affect spinal fusion?

 Smoking significantly intensifies the risk of developing pseudoarthrosis for the patients undergoing both cervical and lumbar fusion procedures. In addition, it also increases the risk of other complications such as dysphagia, infection, and adjacent-segment pathology.

If a brace is recommended , how long does one have to wear it? Does the brace need to be worn at all times, including in the shower?

The spine braces offer good support to the spine. However, its main function is to restrict some spinal movements, and deliver comfort to the patient. A period of around 4 to 6 weeks is usually advised for brace-wearing. Not wearing a brace while taking a shower is no problem, but standing while not wearing it is only advised for a very limited time, while the patient is recovering from the spine surgery.