Anterior Lumbar Interbody Fusion: ALIF
ALIF is a surgical technique used to manage degenerative conditions of the lumbar spine / low back when all else fails. This website is run by the NeuroSpineClinic in Sydney, Australia and Dr Ralph Mobbs who is a Neurosurgeon with a specialty interest in Spinal Surgery and who has performed over 450 ALIF implants along with the ALIF Team at the Prince of Wales Private Hospital.
Use the website to learn more about the ALIF surgery. Watch the video and read a recent article by Dr Mobbs on the indications for ALIF surgery.
For appiontments or a second opinion on ALIF surgery, contact the NeuroSpineClinic on 02 9650 4766.
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ALIFPre and postop![]()
ALIFCorrection of previous failed surgery![]()
ALIFSurgery![]()
ALIFBack Pain![]()
ALIFDegenerative Disc Disease![]()
ALIFImplant![]()
L5/S1 Incision![]()
Disc Replacement![]()
ALIFApproach and Implants
What is an anterior lumbar interbody fusion (ALIF)?
A spinal fusion is a surgical procedure which results in two or more bones being joined together in a solid and stable fashion by bridges of bone between them. The aim is to stop movement across that particular segment of the spine.
An anterior lumbar interbody fusion (ALIF) is an operation on the lower back which is performed from the front, in other words through the abdomen. It is most commonly used to treat lower back pain resulting from a damaged or degenerate intervertebral disc, or spondylolisthesis (slippage of one bone on the other). The goal is to stabilise the spine so that pain (and sometimes deformity) is reduced.
Anterior lumbar interbody fusion (ALIF) involves the removal of one or more intervertebral discs and the joining of two or more spinal bones (vertebrae) together using screws and a cage.
Why might I need an ALIF?
An ALIF is advised for some patients who may have the following conditions:
- Discogenic lower back pain (pain arising from the intervertebral disc)
- Spondylolisthesis (slippage of one vertebra on another, with pain and instability)
- Failed previous fusion surgery.
Surgery is usually recommended when all reasonable conservative measures (pain medications, nerve sheath injections, physical therapies, braces etc.) have failed.
When is an ALIF not recommended?
An ALIF may not be recommended when there is:
- Obesity (this makes the approach difficult)
- A history of multiple abdominal surgeries (this may make the approach hazardous)
- Significant pressure on the spinal nerves (this requires a decompressive procedure, which is performed from the back)
In some cases, an ALIF may be followed by a posterior decompression and/or stabilisation procedure.
How does an ALIF compare with other types of fusion surgery?
An ALIF approach has several advantages over spinal fusions performed from the back (via a posterior approach), including PLIF, TLIF, and posterolateral fusion:
- the muscles of the lower back remain undisturbed, with less postoperative back pain
- the spinal nerves are not manipulated, so there is less chance of nerve damage
- more extensive disc removal and disc space preparation is undertaken, with better fusion rates
The main disadvantage of an anterior approach is that the spinal nerves cannot be decompressed (when this is required, a posterior approach is indicated).
What are the potential benefits of an ALIF?
The goals of an ALIF may include:
- Reduction of back pain
- Stabilisation of an unstable spine
- Medication reduction
- Prevention of deterioration
- Improved lower back and leg function
- Improved work and recreational capacity
- Improved quality of life
The chance of obtaining a significant benefit from surgery depends upon a wide variety of factors. Your neurosurgeon will give you an indication of the likelihood of success in your specific case.
What are the specific risks of an ALIF?
Generally, surgery is fairly safe and major complications are uncommon. The chance of a minor complication is around 4 or 5%, and the risk of a major complication is 2 or 3%. Over 90% of patients should come through their surgery without complications.
The specific risks of an ALIF include (but are not limited to):
- Failure to fuse (non-union)
- Fail to benefit symptoms or to prevent deterioration
- Worsening of pain
- Infection
- Blood clot in wound requiring urgent surgery to relieve pressure
- Cerebrospinal fluid (CSF) leak: this risk is much higher in revision (re-operation) surgery
- Surgery at incorrect level (this is rare, as X-rays are used during surgery to confirm the level)
- Blood transfusion
- surgery is performed very close to the large blood vessels that go to the legs
- injury to these large blood vessels may cause substantial blood loss
- Screw and/or cage breakage, movement, or malposition, sometimes requiring further surgery
- Cage or graft dislodgement (expulsion)
- Nerve damage (weakness, numbness, pain) occurs in less than 1%
- Major neurological problems are fortunately rare, but include:
- paraplegia (paralysed legs)
- incontinence (loss of bowel/bladder control)
- impotence (loss of erections)
- Chronic pain (may require further surgery)
- Failure to fuse (pseudoarthrosis)
- Adjacent segment disease (deterioration of the disc above or below due to the extra stress caused by the fusion)
- Injury to the bowel, ureter (the tube running from your kidneys to the bladder), or spermatic cord
- Retrograde ejaculation in men
- occurs in less than 5% of cases (the real figure is probably closer to 1%)
- the nerves (known as the superior hypogastic plexus) that control ejaculation are draped over the front of the L5-S1 disc
- these nerves are very sensitive, and ejaculation can be disrupted
- ejaculation then occurs into the bladder, rather than out through the penis
- erection and sex drive are rarely affected
- it often resolves with time (several months to a year)
- Incisional hernia (this may require corrective surgery)
- Post-operative ileus (slowing of the bowels, which usually settles over a few days)
- Injury to the diaphragm or kidney
- Deep venous thrombosis and pulmonary embolism (formation of blood clots in the leg veins, and these may break off and travel to the lungs, which can be life-threatening)
- Death (this is extremely rare)
How is an ALIF performed?
A general anaesthetic will be administered to put you to sleep. A breathing tube (‘endotracheal tube’) will be inserted and intravenous antibiotics and steroids injected (to prevent infection and post-operative nausea). Calf compression devices will be used throughout surgery to minimise the risk of developing blood clots in your legs. A catheter will be inserted into your bladder to prevent bladder distension during surgery and to monitor urine output. You will be placed face-up on the operating table.
Your abdomen will be cleaned with antiseptic solution and some local anaesthetic will be injected.
An 8-12cm incision is made on the left side of the abdomen or in the midline, usually just below your umbilicus (belly-button). The abdominal muscles (rectus abdominus) are gently pulled to one side and the sac containing the abdominal contents (peritoneum) is similarly retracted. This is known as a retroperitoneal approach.
Sometimes, a transperitoneal approach is utilised: the peritoneum is incised and the abdominal contents retracted to approach the spine more directly.
The large blood vessels that run to the legs (the aorta and vena cava) are gently mobilised retracted off of the anterior aspect of the spine. The ureter is also identified and protected. At L5-S1, the superior hypogastric plexus is gently mobilized to expose the disc space.
A small needle is then inserted into the disc and an x-ray is performed to confirm that the surgeon is at the correct disc is being exposed.
A microdiscectomy is performed. This is done by first cutting the outer annulus fibrosis (fibrous ring around the disc) and removing the nucleus pulposus (the soft inner core of the disc). Disc removal is performed using a combination of special instruments.
The boundaries of the disc space (the vertebral end-plates) are then carefully prepared to facilitate fusion.
A special interbody cage (made of carbon fibre, PEEK, or trabecular metal) is then inserted into the disc space and secured in place with screws. This cage is typically filled with a combination of bone shavings, tricalcium phosphate, and bone morphogenetic proteins.
A final X-ray is taken and the wound is closed with dissolving sutures or with staples.
What happens immediately after surgery?
It is usual to feel some pain after surgery, especially at the incision site. Pain medications are usually given to help control the pain. While tingling sensations or numbness is common, and should lessen over time, they should be reported to your neurosurgeon.
Most patients are up and moving around within several hours of surgery. This is encouraged in order to keep circulation normal and avoid blood clot formation in the legs.
You will be able to drink after 4 hours, and should be able to eat the next day (once you have developed bowel sounds).
A CT scan will be performed the next day to check the position of the screws and cage.
You will be discharged home when you are comfortable, usually after 3-5 days.
What happens after discharge?
You will need to wear a special brace for 3 months after surgery whilst you are sitting, standing or walking. You will need to take it easy for 8 weeks, but should walk for at least an hour every day. You should avoid sitting for more than 15-20 minutes continuously during this time.
At 6-8 weeks it is likely that you will be able to return to work on “light duties” and to drive a motor vehicle on short trips. This, and the step-wise progression in your physical activities, will be determined on an individual basis.
Bear in mind that the amount of time it takes to return to normal activities is different for every patient. Discomfort should decrease a little each day. Increases in energy and activity are signs that your post-operative recovery is progressing well. Maintaining a positive attitude, a healthy and well-balanced diet, and ensuring plenty of rest are excellent ways to speed up your recovery.
Signs of infection such as swelling, redness or discharge from the incision, and fever should be brought to the surgeon’s attention immediately.
You will be reviewed after 6-8 weeks by your neurosurgeon. Until then, you should not lift objects weighing more than 2kg, and should not engage in bending or twisting movements.
The results of fusion surgery are not as good in patients who smoke or are very overweight. It is therefore important that you give up smoking permanently before your surgery and try to lose as much weight as possible.
You should continue wearing your TED stockings for a couple of weeks after surgery.
What are the results of surgery?
Overall, over 85% of patients will obtain a significant benefit from surgery, and this is usually maintained in the long term.
It is important to note that few patients become completely free of symptoms- the goals are pain and medication reduction, as well as prevention of deterioration.
Despite performing a technically satisfactory operation, a solid bony fusion does not always occur. Patients can control certain factors which may be important in determining whether or not a solid fusion occurs, including:
- Smoking. It is advisable to quit smoking before undergoing a spinal fusion procedure, and not to resume smoking afterwards. Nicotine often prevents solid bone from bridging the disc space.
- Motion. Bone generally forms better if motion is limited. Patients are therefore advised to wear a lumbar brace and to avoid bending, lifting, and twisting for three months after surgery.