Spinal fusion is a surgical procedure performed to “fuse” two or more vertebrae together. It is done with the use of a bone graft material and surgical hardware such as plates, rods, or screws to allow healing of the affected area as a one solid unit. Fusion surgery is performed to help reduce back pain or neck pain resulting from a number of diagnoses. This surgery is considered only after all conservative measures have not provided significant relief.
The spine is made up of interconnected bones termed as the vertebra, which starts from the base of the skull and ends to the tailbone at the lower back. Each bony vertebra sits on top of one another forming the vertebral column. In between each of these vertebral body lays a disc cushion called intervertebral discs. These discs serve as shock absorbers, linking the vertebrae together. These discs also permit the bending and twisting motion of the spine, along with the help of facet joints. Protected within the spinal column is the spinal cord that connects the brain to the rest of the entire body. Spinal nerves arise from this nerve bundle in pairs, one on every side of the vertebra.
There are many different ways to fuse a spinal segment. The surgical approach and the exact type of spinal fusion performed depend on the individual’s pain complaints, history of previous surgery, medical health and spinal structure. The number of levels involved in the fusion depends on the disc levels identified as problematic through diagnostic studies prior to surgery. The particular fusion graft or device to use during surgery will be determined by the surgeon. This decision is based upon individual anatomy, levels of involvement, patient’s medical health and overall patient safety.
Because the duration of some of these surgeries and because the need to manage the body’s fluids during surgery, a bladder catheter is often placed after beginning anesthesia. This will be removed as soon after surgery as is safe – sometimes in the recovery room.
Your surgeon may choose to place a drain in the surgical site at the conclusion of the procedure. This is used to remove excess fluid from the site. It will be removed when it is no longer needed. Patients are encouraged to quit smoking or using any tobacco products prior to undergoing fusion. Smoking may inhibit the bone from growing together to form a solid spinal fusion. In some patients, the bone fails to grow strongly together. This is called “pseudoarthrosis.”
Your surgeon may recommend spinal fusion if any of the following conditions occur:
• Trauma resulting to a fractured spine or broken vertebra
• Spinal deformities – as a result of scoliosis or kyphosis
• Spondylosis – a degenerative arthritic disorder that may result to a loss of normal spinal curvature, structure, and function
• Weakness or instability of the spine – causing nerve impingement, and pain
• SpondyloIesthesis – a condition wherein one vertebrae slides forward relative to the one below
• Herniated or damaged intervertebral discs – also known as ‘slipped disc’, is a condition in which the disc bulges out causing pressure on spinal nerve
Spinal fusion is designed to reduce movement and immobilize the affected vertebrae making the spine more stable. This technique helps prevent further compression or damage to the spinal cord and nerves.
Spinal fusion is generally a safe surgical procedure. But as with any operation, this type of surgery is associated with different potential risks or complications, which include:
• Poor wound healing
• Blood clots
• Recurring symptoms
• Pain at the graft site
• Blood vessel or nerve injury
Beyond these complications and risks, spinal fusion works by decreasing the added stress that may accelerate with the progression of wear and tear of the affected vertebral column.
Before the procedure, an I.V. (intravenous) line will be initiated. An indwelling catheter may also be ordered by your physician to drain your urine.
The procedure is done under general anaesthesia. This means that you will be asleep for the whole duration of the procedure. A tube to aid you breathing may be inserted through your mouth to help you breathe during the operation.
If your surgeon is using your own bone for the spinal fusion, he or she will first make an incision on your hip area and gather a ‘bone graft’. If the bone graft is from another person, it will be harvested before your procedure.
If the affected area is on your lower back, and your surgeon chooses an open procedure, you will be placed on a prone position (lying on your stomach) during the procedure. The surgeon will then, create an incision over the region of the affected vertebrae.
In some cases, a spinal fusion may be performed via laparoscopic technique, a less invasive procedure. This technique necessitates several tiny keyhole incisions (rather than one or two large incisions if open surgery), through which the laparoscope and other special surgical instruments are inserted.
The procedure involves insertion of the bone graft in between the spaces of two vertebrae. The surgeon may place a plate and screws over the graft to join and hold the vertebral body together until they ‘fuse’ into one bone.
To complete the procedure, the surgeon will close the incision with stitches.