Spinal Fusion

Spinal fusion involves permanent joining of two or more bones of spine (vertebrae) to alleviate pain or restore stability of the small bones in the spine that cause these problems.

Spinal column consists of some small bones called vertebrae stacked over each other. The vertebrae are joined to one another by two small joints (facet joints) at the back that help the spine to twist and bend. Each vertebra is separated by an intervertebral disc that acts as a shock absorber and provides flexibility to the backbone. The intervertebral disc is made of an outer fibrous ring called the annulus and a soft centre called the nucleus pulposus. The stack of vertebrae together forms the spinal canal that protects the delicate spinal cord (made up of nerves). Spinal cord helps to send and receive information between the brain and different parts of the body.

Certain conditions such as cracks in vertebrae and wear and tear of the facet joints and intervertebral discs may result in significant pain in the back and leg along with symptoms like stiffness, numbness and tingling. 

If a certain section of the spine is found to cause these symptoms upon investigation, spinal fusion may be performed to join or fuse the affected vertebrae. Spinal fusion stabilises the junction between the vertebrae and protects the nerves passing through them, thus helping manage the condition.

This surgery is recommended in individuals with the following conditions:

• Spinal stenosis: The symptoms of the condition include:
  • Neck pain
  • Lower back pain
  • Problems with balance
  • Heavy feeling in legs
• Spondylolisthesis: Symptoms of spondylolisthesis include:
  • Back stiffness
  • Pain while bending
  • Difficulty standing or walking for extended periods
  • Numbness or tingling sensation in the foot
• Degenerative disc disease: The common symptoms of this condition include:
  • Pain that worsens while sitting, twisting, or bending
  • Tingling or numbness in extremities (arms and legs)
  • Weakness in leg muscles
  • Nagging to disabling pain in the lower back, thighs, or buttocks
• Scoliosis: Symptoms of this condition include:
  • Uneven waist or shoulders
  • The body leans to one side
  • Hairy patches, dimples, or colour abnormalities on the skin over the affected vertebrae
• Spinal fracture: The symptoms of a spinal fracture include:
  • Hunched forward posture
  • Inability to walk normally
  • Severe pain in the affected area
  • Swelling over the affected vertebrae
• Spinal infection: The symptoms of the condition are:
  • Pain at the site of the infected vertebrae
  • Redness, tenderness, or swelling
  • Weight loss
  • Fever
• Spinal tumours: Spinal tumours are associated with the following symptoms
  • Stiffness in the back or neck
  • Loss of bladder or bowel function
  • Difficulty walking
  • Muscle weakness in the chest, arms, or legs

Spinal fusion may also be performed with other surgeries, namely laminectomy, foraminotomy, or discectomy.

Contraindications to this surgery include individuals who have:

• Arachnoiditis (inflammation in arachnoid - a membrane protecting the brain)
• Epidural scarring (scarring from an earlier spine surgery)
• Active infection

Prior to the surgery, the doctor will perform a few tests to decide whether you are a right candidate for the procedure and to look for the presence of any coexisting conditions that need to be treated first. The tests include:

• Blood tests
• Pregnancy test
• X-ray
• Magnetic resonance imaging (MRI)

The surgeon will give you certain instructions to prepare for the surgery. During the discussion, he/she will ask you to:

• Share a list of all the medications that you take, including herbs and over-the-counter medications. 
• Discontinue blood-thinning medicines (such as warfarin, aspirin and ibuprofen) a week before the surgery.
• Stop smoking. This will help reduce the risk of complications and help you heal faster after the surgery.
• Fast from midnight before the surgery.
• Take a shower and remove all your body piercings, make-up, and nail polish before arriving at the hospital for the surgery.
• Arrange for a friend, family member, or responsible adult to drive you home after the procedure.
• Sign an approval form if you agree to the procedure.

Once you reach the hospital, the hospital staff will provide you with a hospital gown. They will also insert an intravenous (IV) line in your arm to supply essential fluids and medications during the surgery.

The surgery can be performed by an open procedure or a minimally invasive procedure. Compared to the open method, the minimally invasive surgery requires a smaller incision, reduces damage to the muscles and tissues over the spine, and has a shorter recovery and rehabilitation period.  The surgeon may access your spine by any of the following approaches:

• Anterior approach: An incision (cut) is made in the front part of the body (front of the neck or lower abdomen).
• Posterior approach: The spine is approached from the back.
• Lateral approach: This is performed from the side of the body.

Minimally invasive spinal fusion involves the following:

• You will be asked to lie on an operating table either on your side or back, depending on the approach used to access the vertebrae.
• An anesthesiologist will give you general anaesthesia to put you into a deep sleep.
• A tube will be inserted into your throat to help you breathe. and your vital signs will be monitored throughout the surgery.
• Your surgeon will administer you antibiotics to reduce your risk of infection.
• He/she will make a cut on your back or side and separate the muscles and tissues over your spine.
• Next, the surgeon will fuse two or more of your affected vertebrae by any of the following methods:
  • He/she will remove your intervertebral disc and replace it with a bone graft.
  • He/she will fill the back part of your spine with strips of bone graft material.
  • He/she will place a special implantable cage (synthetic bone-like material) between the affected vertebrae.

The bone graft will be obtained from your hip bone or a bone bank, or the surgeon may use an artificial bone substitute.

• The surgeon will use screws, rods, or plates to prevent any movement of the operated vertebrae until the bone graft heals completely.
• He/she will put together the separated layers of your muscles and tissue and close the incision.

A tube will be left in the incision to prevent the formation of blood clots. The surgery will last for about three to four hours. After the procedure, you will need a hospital stay of about three to four days. During this period, you can expect the following:

• A nurse will give you medications (either administered through an IV or orally) to control pain.
• You will be fed through an IV. You may be able to eat soft foods; however, it may take two to three days to resume your regular diet.
• The surgeon will perform an X-ray to ascertain the success of the surgery.
• A physical therapist will visit and teach you to sit, stand, and walk without twisting or bending your spine. 
• You will be discharged in a few days with a cast or back brace to support your back.

After surgery, you will need to take care of yourself in the following manner:

• Keep the site of operation dry for a week. While showering, cover the wound with a plastic wrap.
• You may experience pain after the surgery, for which you will be prescribed medications. Some tips that can be employed to handle back pain include:
  • Apply ice over the pain-affected area for two to three days and use heat thereafter.
  • Avoid twisting your back or doing heavy lifting exercises for at least six weeks from when the pain begins.
  • Sleep in a foetal position using a pillow between your legs. While sleeping on your back, place a pillow under your knees.
• Do not sit for more than 20 to 30 minutes at a time.
• Wear a back brace while walking or sitting.
• While lifting objects, do not bend at the waist; instead, bend in your knees.
• You can start walking short distances for two weeks, and gradually increase your pace and distance over the next few days. As you recover, you will need to undergo physical therapy for six weeks to three months.
• Avoid driving for at least two weeks after the surgery. You should resume driving only after consulting your surgeon.
• Rest for at least a month and a half before resuming work. It may take about six months to recover from the surgery, depending on the age and severity of the surgery.

Although you may have an improvement in back pain after the surgery, it will be highly unlikely that the surgery will treat all your pain and other symptoms. You may get better results from spinal fusion if you lose weight and exercise regularly.

When to see the doctor?

Contact the surgeon if you experience the following symptoms:

• Pain in the calf
• Swelling in the foot, ankle, or calf
• Swelling, redness, or tenderness around the operated site
• Discharge from the incision
• Fever and chills
• Pain in the back or around the operated area

The potential complications associated with the surgery include:

• Nerve damage
• Paralysis of leg muscles, bowel, or bladder
• Leakage of spinal fluids
• Wound infection
• Degeneration of vertebrae around the fusion
• Formation of blood clots
• Breathing problems
• Reaction to medicines

After undergoing surgery, you cannot move the spine at the region of the fused vertebrae. Moreover, it is highly likely that the vertebrae below and above the fused vertebrae will be under stress during activities that require the movement of the spine and may cause problems in the future.

You will need to revisit the surgeon a week after the surgery to get the stitches removed.

Disclaimer: The above information is provided purely from an educational point of view and is in no way a substitute for medical advice by a qualified doctor.