A transforaminal interbody lumbar fusion (TILF) is a surgical procedure that involves permanent union of some of the bones of the lower back (lumbar area). A TILF is a specific procedure that utilizes a bone graft—bone tissue acquired from a bone bank or taken from somewhere in a person’s own body. Over time, the bone graft and segments of the bones of the person’s spine grow together, forming one “fused” bone.
The procedure is done to permanently fuse some of the bones of the lower spine to remove the pressure (decompress) from the spinal cord and nerves. A TLIF procedure re-stabilizes the spine, preventing further movement and degeneration of the joints that have been impacted by a disease (such as degenerative disc disease) or an accident (such as a car accident that caused a herniated disc).
In general, a spinal fusion prevents movement between the vertebrae and subsequentlSpinal Anatomy
To thoroughly understand a spinal fusion procedure (such as a TLIF) one must understand some of the common terminology of the spine, these terms include:
The spine: An adult spine is comprised of 24 bones which are called vertebrae. The vertebrae are stacked up on top of each other; they begin at the base of the skull and extend downward to the pelvis.
The vertebrae: Each vertebra is made up of several parts, including the vertebral body (which is the primary portion of the vertebra). The front of the vertebral body protects the spinal cord and nerve roots. Together the 24 vertebrae function to protect the spinal cord and nerves, as well as to provide structure so the body can maintain an upright position.
The vertebral discs: The discs are structures between each vertebra which includes an outer layer and a gelatin-like center, which acts to absorb shock and cushion the impact between the vertebrae.
Spinal canal: The bony tunnel that surrounds the spinal cord is made up of the front portion called the vertebral body, the pedicles on the sides of the vertebral body and the lamina in the back.
Lamina: This is the top of the spinal canal that protects the backside of the spinal cord. The lamina is the part of the vertebra that connects the spinous process (a bony projection off the posterior of the back) and the transverse process. The lamina is commonly the site of back surgery when the aim is to relieve pressure on the spinal nerve roots.
Facet joints: There is a paired joint on the right side of each vertebra, and another paired joint on its left side; this allows for a connection above and below each vertebra.
The medical terminology for the acronym “TLIF” includes:1
Transforaminal—through the opening of the spinal column called the “foramina,” which is where the nerve roots exit the spine
Lumbar—referring to the spine in the lower back
Interbody—between the vertebral bodies
Fusion—the process of fusing the bones together
The Purpose of a TILF
There are several reasons that a TILF procedure may be required, including:2
Herniated discs: A condition in which the outer portion of the vertebral disc is torn, enabling the inner portion to extrude through the fibers. The herniated material compresses the nerves around the disc and creates pain
Spondylolisthesis: A condition that occurs when the vertebral bone moves out of its normal position, this can compress the nerve, causing severe back pain
Mild to moderate scoliosis: A curvature of the spine caused by bones that are misaligned, in adults, scoliosis can occur due to aging, arthritis or as a result of a previous back surgery
Degenerative disc disease: The process of shrinkage of the disc that occurs from aging; the disc thins or herniates (protrudes through an abnormal body opening) which causes the bones to rub and pinch the nerves (usually resulting in severe back pain)
Spinal stenosis: The narrowing of the spinal canal causing ligaments to pinch the nerves which can result in pain and numbness in the lower extremities.
A fractured vertebra: Most commonly due to a motor vehicle accident or similar event that causes a severe impact
An infection of the spine
A tumor (pressing on the spinal nerves)
Severe back pain that is not relieved by physical therapy or other treatment modalities
Each of these conditions may cause the spinal cord to become weak and unstable.
Risks and Contradictions
Those who are not a candidate for TLIF include:3
Those with severe osteoporosis (softening of the bone tissue)
Those who have had a prior fusion at the same level of the spinal column
Those with conditions that may prevent bones to fuse properly
Although complications of a TLIF procedure are not common, there is no way that a person can know for sure that the spinal fusion will take. Normally the procedure will result in bone fusion and significant improvement in pain level. But there is no guarantee. Just as with any other surgical procedure, the benefits and risks must be weighed before a person is considered a candidate.
Specifically, there are several complications that could result from a TLIF procedure, these may include:
Failure of the vertebrae to fuse: This may result in the need for another surgical procedure if the fusion doesn't take or the fused area doesn’t heal properly, common causes may include:2
Osteoporosis (softening of the bone tissue)
Hardware fracture: This may occur when metal screws used during the procedure (that stabilize the spine) break before the bones completely fuse together. In this instance, another surgical procedure may be required to fix or replace the broken hardware.
Bone graft migration: This is a rare occurrence involving bone graft that moves from its intended position to between the vertebrae.4 It occurs most often when plates, screws or other hardware are not used to temporarily fuse the area before the bones completely fuse together. When bone graft migration occurs, another surgery may be required to fix the problem.
Transitional syndrome (adjacent segment disease): This results from added stress to the load on the discs directly above and below the fusion site. This can eventually cause degeneration of the adjacent discs, often resulting in severe back pain.5
Nerve damage: Any type of spinal surgery could potentially cause damage to the nerves or the spinal cord, this could result in numbness or even paralysis in the lower extremities.
Chronic (long-term) pain: A herniated disc, causing nerve damage, is the most common cause of chronic pain after a TLIF. If the damage is permanent, the nerve will not respond to the surgical decompression, and the pain will not be relieved. In some instances, a procedure called spinal cord stimulation (a medical procedure involving electrical impulses that are delivered to the nerves of the spine to block the pain) or other treatments may provide pain relief.
Note, these risks should be reviewed with the surgeon before the procedure to ensure that all concerns are addressed in advance of the procedure.
Before the Procedure
Before a TLIF the healthcare provider will do a preoperative exam and take a patient history report to evaluate for any bleeding problems, past reaction to anesthesia, allergies, current medicines and vitamins/supplements that you are taking and more.6 There are several tests that your healthcare provider may perform, these include:
Preoperative instructions before a TLIF procedure may include:
Discontinue use of certain medications (such as non-steroidal anti-inflammatory medications including, Advil, Motrin, Aleve, aspirin, Plavix [clopidogril], and more) between one to two weeks before the surgery (or as the healthcare provider instructs)
Discontinue use of blood thinners (such as Coumadin [warfarin] and more) between one to two weeks before the surgery (or as the healthcare provider instructs)
Discontinue the use of tobacco (including smoking, chewing tobacco, snuff/dip, nicotine gum or patches, or vaping). Nicotine is linked with interfering with the growth of bone tissue (which is required for the fusion to be successful). In fact, in 40% of smokers (compared to only 8% of non-smokers) fusion was found to fail.6
Discontinue alcohol consumption at least one to two weeks (depending on your surgeon’s instructions) before the surgery to avoid bleeding problems.
Note: Substances that cause failure of bone fusion also include all nicotine replacement and pills with or without nicotine (such as Wellbutrin and Chantix).
The Morning of Surgery
The morning of surgery, the preoperative instructions may include:
Take a shower using antibacterial soap
Take medications (surgeon approved) that are necessary with a very small amount of water
Remove all hardware from hair, body piercings, etc.
Remove jewelry and leave at home (including wedding ring)
Remove nail polish
Arrive at the outpatient center or hospital early (usually two hours before the procedure if you are having it at a hospital and one hour beforehand if the procedure will be performed at an outpatient facility).
The anesthesiologist will usually talk to patients about the anesthesia risks and effects right before surgery. The nurse will place an IV line in the patient's arm (for administering the anesthesia as well as any other medications required during or after the procedure).
The procedure itself will usually take one to two hours, depending on how many spine levels are involved. Early arrival (one hour before for outpatient procedures and two hours before for hospital procedures) will allow time for signing legal forms (such as consent forms) and for any preoperative workups (such as labs) that need to be done the day of surgery.
A TLIF is usually performed either as an inpatient hospital procedure or at an outpatient surgery location.
What to Wear
Wear newly-washed clothing that is not tight-fitting, and flat shoes with closed backs (not sandals, slippers or flip-flops).
Food and Drink
Do not eat or drink fluids (including water) the morning of the surgery.
Cost and Health Insurance
Back surgery is considered one of the most common unnecessary surgical procedures performed. In fact, during a one-year study, published by Surgical Neurology International, it was discovered that "17.2% of 274 spinal consultations seen by a single neurosurgeon were scheduled for unnecessary surgery," according to the study authors.7
Because of these and other statistics, many insurance companies have begun trying to cut down on costs by requiring those who are scheduled for non-emergency back procedures (such as TLIF) to consult with other healthcare providers (such as a physiatrist/rehabilitation specialist) before undergoing surgery. The physiatrist is trained in non-surgical treatment modalities (such as physical therapy) for neuromuscular disorders that cause pain and impair mobility.
What to Bring
Bring a list of medications (prescriptions, over-the-counter, and herbal or natural supplements) with dosages and the times of day usually taken. Bring a list of allergies to medications or foods.
During the Procedure
The incision is made at the back of the spine, but the surgeon is able to access and fuse the bones in the front of the spine—called the vertebral bodies. Fusion between these bodies results in the “interbody fusion” portion of the procedure’s name.
Bone and disc material is removed to allow the surgeon access to the front of the spine. The openings through which the nerve roots exit—called the foramina—are enlarged. This is where the “transforaminal” portion of the procedure’s name comes from. The removal of bone and disc material and enlargement of the foramina makes the TLIF procedure unique from other types of spinal fusion surgeries.
The basic steps of a TLIF procedure include:6
Step 1: The anesthesiologist will administer the anesthesia and position the patient in a prone (downward facing) position, with pillows supporting each side of the body. The incision area of the back is cleaned and prepped for surgery.
Step 2: Once the patient is asleep, the surgeon will make a very small incision, the back muscles are split, using a special tool, to create a path toward the spine.
Step 3: Part of the lamina and facet joint are removed to open the spinal canal and expose the sac that protects the nerves. The surgeon removes ligament and bone spurs to free the nerve.
Step 4: The surgeon gently retracts the nerve and the disc nucleus (jelly-like material located in the inner core of the disc) is removed. Part of the disc remains to hold the bone graft cage (hardware used to support the vertebra during the fusion process)
Step 5: Bone shavers (special tools to remove bone tissue) are utilized to prepare the fusion bed and the bone graft material is prepared for the fusion. A trial spacer (usually, the type called an interbody cage) is inserted into the empty disc space and an X-ray is taken to ensure its proper placement (to adequately decompress the nerves). The spacer also acts as a supportive device between the vertebral bodies. A special type of paste, called bone morphogenic protein (BMP), is used that contains bone-growing proteins. The special paste is packed within the spacer cage.
Step 6: Two sets of screws are placed into the bone (above and below the disc space) and a rod is passed to connect the screws together.
Step 7: A wedged bone graft is used to align the top vertebra and screws are used to pull the bones back into alignment with each other. The hardware provides stability to the vertebrae during the fusion process. Once the bones fuse together, it provides long term stability to the spinal column.
Step 8: The incision is closed.
After the Surgery
Potential risks and complications may include:1
An adverse reaction to anesthesia
An infection at the surgical site
Injury to a nerve
The need for a second fusion or other surgical procedure
Bone tissue that doesn’t fuse solidly
Pain that doesn’t subside or an increase in pain level
Other medical complications (such as blood clots, pneumonia, heart attack or more)
When to Call the Doctor
It’s important to contact the healthcare provider after a TLIF procedure if these symptoms occur:8
A fever (over 101 F not relieved by Tylenol)
Unrelieved nausea or pain
Redness, swelling, itching or draining at the incision site
Swelling and tenderness in the calf of one leg (may indicate a blood clot)
Tingling or numbness in the lower extremities (which did not occur before the surgery)
Dizziness, confusion, nausea, or excessive sleepiness
Home care instructions after the procedure may include:
Avoid these activities after surgery:8
Bending or twisting the back (avoid bending or twisting for six weeks after the procedure, limit bending and twisting for up to three months after the surgery)
Lifting anything over 5 pounds.
Strenuous activity (including housework or yard work)
Smoking, vaping, chewing or using any type of nicotine product
Driving (until after the first follow up appointment)
Alcohol (increases the risk of bleeding and interacts adversely with pain medications)
Get up and walk for five to 10 minutes every three to five hours daily. Gradually increase the time that you walk as tolerated.
Note, the TLIF procedure is done to prevent movement at a joint in the spine. This usually causes stiffness at the level the TLIF was performed.
Incision care after a TLIF procedure may include:8
Washing hands before and after performing wound care
Showering the day after surgery (if Dermabond glue was used to cover the incision)
Washing the incision site gently with soap and water (avoid picking off the glue)
Showering two days after surgery if staples or stitches were used
Avoiding a bath or soaking the incision in a pool
Keeping the incision site dry (don’t apply any ointment or lotion)
Managing Side Effects
Managing the side effects of a TLIF procedure may include:6
To manage pain, take pain medication as directed. As the pain lessens, reduce the frequency of taking pain medication.
If pain is mild, acetaminophen (Tylenol) may be substituted for narcotic pain relievers (with the approval of the healthcare provider).
To reduce pain and swelling at the incision site, use ice three or four times per day (with the approval of the health care provider)
Drink a lot of water to combat constipation if narcotics are ordered for pain, (contact the healthcare provider if high-fiber foods and stool softeners don’t relieve constipation)
If there is drainage, cover the incision with a dry gauze dressing. If the dressing becomes soaked after two or more dressings are applied, contact the healthcare provider. Note, there is normally some clear pinkish drainage, but watch out for an increased volume of drainage or redness at the site
Avoid taking anti-inflammatory pain medications (such as Aleve or Advil) unless ordered by the healthcare provider, these medications prevent new bone growth and may result in a failed fusion.
Avoid sitting in one position for longer than an hour (it may cause stiffness and increase pain).
Don't sit or lie in one position longer than an hour unless you are sleeping. Stiffness leads to more pain.
A follow-up appointment should be scheduled with the surgeon two weeks after surgery. At this time the surgeon will decide when you can return to work.
Recovery time usually can take approximately six to 12 weeks after the procedure.9
The number of lumbar fusion surgical procedures increased from 77,682 to 210,407 between 1998 and 2008, according to a 2018 review study.10
The study looked at a situation called failed back surgery syndrome (FBSS). The overall failure rate of spine surgery was estimated to be between 10% and 46%.
A Word from Verywell
If you are considering a TLIF procedure (or other spinal surgery) it’s best to consider all of the risks and benefits, as well as other treatment options (such as physical therapy) before deciding to get back surgery. A TLIF procedure should only be performed as a last resort after all other treatment options have been explored.y it is aimed at preventing pain that is caused by movement.