Medically reviewed by Erick R. Kazarian, MD, board-certified orthopedic spine surgeon. Last reviewed February 2026.
Approach
Anterior abdominal + robotic posterior fixation
Duration
~2 hours 30 minutes
Hospital stay
Typically 1–3 days
Overview
Anterior lumbar interbody fusion, commonly known as ALIF, is a two-stage spinal surgery that combines an anterior (front) approach through a small abdominal incision with posterior (back) robotic-guided percutaneous pedicle screw fixation. By approaching the spine from the front, Dr. Kazarian gains direct access to the intervertebral disc space without needing to disturb the back muscles, nerves, or spinal canal. Because the anterior portion of the procedure involves working near the major blood vessels in the abdomen, a vascular or general access surgeon assists during the approach to safely move these structures aside and create a clear path to the spine. The posterior screws are then placed through small incisions in the back using a state-of-the-art robotic navigation system for maximum precision.
ALIF offers several distinct advantages compared to a single posterior (back) approach to spinal fusion. The anterior approach allows Dr. Kazarian to place a larger interbody implant directly into the disc space, which provides a broader surface area for bone fusion and improved structural support. This larger implant also helps restore the natural curvature (lordosis) of the lumbar spine, which is essential for balanced posture and long-term spinal health. The posterior pedicle screws are placed percutaneously, meaning through tiny stab incisions, using a robotic arm that maps your spine in three dimensions and guides each screw along a pre-planned path with sub-millimeter accuracy. This combination of an anterior implant with robotic-assisted posterior fixation delivers the structural benefits of a 360-degree fusion while keeping tissue disruption to a minimum. ALIF is most commonly performed at the L4-L5 and L5-S1 levels of the lumbar spine, where the anterior approach provides excellent visualization and access.
Whether you are dealing with degenerative disc disease, spondylolisthesis, or a failed previous spinal surgery, ALIF may be a highly effective option for relieving pain and restoring spinal stability. Our surgical team, including both your spine surgeon and the vascular access surgeon, will work together to ensure the safest and most successful outcome. We are committed to guiding you through every phase of your care, from your initial consultation through your full recovery.
Dr. Kazarian performs ALIF at NYU Langone Health in New York City and evaluates patients at offices in Midtown East, the Penn District, and Tarrytown, NY.
Who it's for
Patients with degenerative disc disease, spondylolisthesis, or a failed previous spinal surgery, most commonly at the L4–L5 and L5–S1 levels.
Why patients choose this approach
- Direct disc access without disrupting back muscles
- Allows excellent restoration of disc height and alignment
- Robotic-guided posterior screw placement for precision
What to expect on surgery day
Knowing what to expect before, during, and after your anterior lumbar interbody fusion can help ease any anxiety and allow you to feel confident and prepared. Here is an overview of your surgical experience, step by step.
- 1
Check-In and Pre-Operative Preparation
You will arrive at the hospital approximately two hours before your scheduled surgery time. Our nursing team will verify your identity, review your medical history, and confirm the surgical level with your spine surgeon. An IV line will be placed, and you will change into a hospital gown. Both your spine surgeon and the vascular access surgeon will visit you to review the procedure and answer any remaining questions. Your anesthesiologist will also discuss the anesthesia plan and any concerns you may have.
- 2
Anesthesia and Positioning
ALIF is performed under general anesthesia, so you will be completely asleep and feel no pain during the procedure. Once anesthesia is administered, you will be carefully positioned lying flat on your back (supine position) on the operating table. Your abdomen will be cleaned and draped in a sterile manner. The supine position allows the surgical team to access the spine through the front of the body, and your care team will ensure all pressure points are properly padded for your comfort and safety.
- 3
Abdominal Approach and Vascular Mobilization
The vascular or general access surgeon will begin by making an incision in your lower abdomen, typically three to five inches in length. The abdominal muscles are gently separated rather than cut, and the peritoneum (the lining of the abdominal cavity) is carefully moved aside. The access surgeon then identifies and gently retracts the major blood vessels, including the aorta and vena cava or the iliac vessels, to create a safe corridor directly to the front of the spine. This collaborative approach ensures that these critical structures are protected throughout the procedure.
- 4
Disc Removal and Implant Placement
With the spine now fully visible, Dr. Kazarian removes the damaged or degenerated disc material from between the vertebrae. The disc space is carefully prepared and measured, and a precisely sized interbody implant (often made of PEEK, titanium, or bone allograft) is placed into the space. The implant is packed with bone graft material to promote fusion. The direct anterior view allows Dr. Kazarian to position the implant optimally, restoring the proper height and curvature of the lumbar spine. Once the implant is securely in place, the vascular surgeon allows the blood vessels to return to their natural position and the abdominal incision is closed.
- 5
Robotic-Guided Posterior Pedicle Screw Placement
After the anterior stage is complete, you will be repositioned and Dr. Kazarian will place posterior percutaneous pedicle screws through small incisions in your back. This is where the procedure takes advantage of cutting-edge robotic technology: a robotic arm, guided by a three-dimensional CT-based navigation system, maps your unique spinal anatomy in real time and guides each screw along a pre-planned trajectory with remarkable precision. The robotic system allows for sub-millimeter accuracy in screw placement, which means smaller incisions, less time in the operating room, and greater confidence that every screw is in the ideal position. The screws and connecting rods lock the treated segment in place and provide the stability needed for the bone graft to fuse solidly over the coming months.
- 6
Closing the Posterior Incisions
After all posterior screws and rods are in place and final imaging confirms proper alignment, the small posterior incisions are closed with dissolvable sutures and covered with sterile dressings. In some cases, a small drain may be placed near one of the incision sites to prevent fluid buildup; this is typically removed before you are discharged.
- 7
Recovery Room
You will be transferred to the post-anesthesia recovery area, where nurses will closely monitor your vital signs, pain levels, circulation in your legs, and abdominal function. You will then be moved to your private room, where your care team will continue to monitor your recovery. A physical therapist will help you safely sit, stand, and walk during your hospital stay. Most patients are discharged one to three days after surgery.
Preparing for surgery
Careful preparation before your anterior lumbar interbody fusion is essential for a safe procedure and a smooth recovery. Please follow these instructions closely, and contact our office with any questions.
Review all current medications and supplements with Dr. Kazarian.
2 weeks before surgeryStop blood thinners (warfarin, aspirin, Plavix), NSAIDs (ibuprofen, naproxen), and herbal supplements (fish oil, vitamin E, ginkgo) as directed. GLP-1 receptor agonists (Ozempic, Wegovy, Mounjaro, Trulicity, Saxenda) must be stopped 7 days before surgery due to the risk of aspiration under anesthesia. Do not stop any medication without Dr. Kazarian's approval.
Medications
Obtain medical clearance from your primary care physician and any relevant specialists.
2-4 weeks before surgeryThis may include blood work, an EKG, and a health review. Bring clearance letters and your CPAP machine (if applicable) on surgery day.
Other
Follow the bowel preparation instructions provided by Dr. Kazarian's office.
1 day before surgeryThis may include a clear liquid diet, a gentle laxative, or specific dietary changes the day before surgery. A clean bowel allows safer abdominal access.
Preparation
Do not eat or drink anything after midnight the night before surgery.
After midnight the night before surgeryThis includes water, coffee, gum, and mints. You may take approved medications with a small sip of water.
Eating & drinking
The NYU perioperative team will call you the day before surgery with your arrival time.
Day of surgeryLocation: NYU Langone Kimmel Pavilion, 424 East 34th Street, Manhattan. Bring a valid photo ID, insurance card, and medication list.
Arrival
Arrange for a responsible adult to drive you home and stay with you for 24-48 hours.
Arrange before surgery dayYou cannot drive after general anesthesia. Your driver should stay at the hospital during the procedure.
Transportation
Recovery
Recovery from anterior lumbar interbody fusion with robotic-guided posterior pedicle screws is a gradual process that unfolds over several months. Because the anterior portion is performed through the abdomen, you may experience some abdominal soreness and temporary changes in bowel function during the early days. The posterior screw incisions are small and typically cause only mild tenderness. Most patients notice significant improvement in their leg and back pain within the first few weeks. The bone fusion process takes approximately six to twelve months, during which time you will gradually increase your activity level under the guidance of your surgical team. Our goal is to help you return to a comfortable, active life with a stable and well-aligned spine.
Early Hospital and Home Recovery
You will spend one to three nights in the hospital, where the team will monitor your pain, circulation, and return of bowel function. Walking short distances with assistance typically begins the day after surgery and is essential for promoting healing and preventing blood clots. Once home, focus on rest, gentle walking, and allowing both the abdominal incision and the small posterior screw incisions to heal. You may experience mild abdominal bloating or changes in appetite as your digestive system returns to normal, along with mild tenderness at the posterior incision sites.
- No bending, lifting, or twisting (BLT precautions)
- Do not lift anything heavier than 5 pounds
- No driving while taking opioid pain medications
- Avoid prolonged sitting for more than 20 to 30 minutes at a time
- No soaking the incision in water (no baths, pools, or hot tubs)
Gradual Activity Increase
Most patients begin to feel noticeably better during this period, with decreasing abdominal and back discomfort. You will gradually increase your walking distance and duration each week. Dr. Kazarian may clear you to begin driving once you are off opioid medications and can safely turn to check blind spots, typically around three to four weeks. Light daily activities such as cooking and self-care become more manageable. Your incision should be well healed by the end of this phase.
- Continue to avoid lifting more than 10 pounds
- No vigorous exercise, running, or high-impact activities
- Avoid prolonged sitting beyond 30 to 45 minutes without a break
- Continue BLT (bend, lift, twist) precautions as directed
Physical Therapy and Strengthening
Dr. Kazarian will likely recommend beginning a structured physical therapy program around the six-week mark. Physical therapy will focus on core stabilization, gentle lumbar flexibility, and gradually rebuilding strength in the muscles that support your spine. Many patients return to desk-based or light-duty work during this period, depending on the physical demands of their job. Imaging may be performed to assess early signs of bone fusion.
- Avoid heavy lifting over 15 to 20 pounds until cleared
- No contact sports or high-impact activities
- Follow your physical therapist's exercise progression carefully
Fusion Maturation and Full Recovery
By three to six months, the bone graft within the interbody implant is expected to mature and solidify into a solid fusion. Dr. Kazarian will evaluate the fusion progress with follow-up imaging. As the fusion becomes solid, you will be able to return to most normal activities, including more strenuous physical tasks and recreational exercise. Patients with physically demanding jobs may be cleared to return to full duty during this period. Most patients report substantial or complete relief from their preoperative leg and back pain by this stage.
- Follow Dr. Kazarian's clearance for return to full activities
- Continue core strengthening and good body mechanics long-term
Follow-up schedule
- 2 weeks after surgery: Incision check, wound healing assessment, and review of early recovery progress
- 6 weeks after surgery: Clinical evaluation of pain and neurological function, possible X-rays, discussion of return to driving and light work
- 3 months after surgery: X-rays to assess fusion progress, physical therapy progress review, and gradual return to more activities
- 6 to 12 months after surgery: Follow-up imaging to confirm solid fusion and final assessment of outcomes
When to call us
- Fever of 101.5 degrees Fahrenheit (38.6 degrees Celsius) or higher, which may indicate infection
- Increasing redness, swelling, warmth, or drainage from the abdominal incision
- Severe or worsening abdominal pain, significant bloating, inability to pass gas, or persistent nausea and vomiting, which may indicate ileus (temporary bowel paralysis) or other abdominal complications
- New or worsening leg pain, numbness, tingling, or weakness that was not present before surgery
- Signs of vascular complications, including sudden leg swelling, coldness, discoloration, or loss of pulse in one or both legs
- Difficulty urinating, inability to empty your bladder, or loss of bowel or bladder control
- Sudden onset of chest pain, shortness of breath, or calf swelling and tenderness, which may indicate a blood clot
- Severe or uncontrolled pain that is not adequately managed by your prescribed medications
Specific medication instructions are provided at discharge and reviewed with you before you go home.
Risks
All surgical procedures carry some degree of risk. Dr. Kazarian takes every precaution to minimize these risks, and serious complications are uncommon. Understanding the potential risks helps you make an informed decision and know what to watch for during your recovery.
Infection
There is a small risk of infection at the surgical site or deeper around the spine. Antibiotics are given before and after surgery to reduce this risk. Signs of infection include increasing redness, swelling, warmth, or drainage from the incision, as well as fever.
Blood Loss
Some blood loss is expected during spinal fusion surgery. In rare cases, significant blood loss may occur that requires a blood transfusion. Your surgical team monitors blood loss closely throughout the procedure.
Cerebrospinal Fluid Leak
The protective membrane (dura) surrounding the spinal cord and nerves may occasionally be opened during surgery, allowing spinal fluid to leak. If this occurs, it is typically repaired during the procedure. In rare cases, additional treatment may be needed after surgery.
Adjacent Segment Disease
After fusion, the spinal segments above and below the fused area may experience increased stress over time. This can lead to degeneration at those neighboring levels, potentially causing new symptoms months or years after surgery. Not everyone who has a fusion develops this condition.
Neurologic Injury
There is a small risk of injury to the spinal nerves during surgery, which could result in new or worsened numbness, tingling, weakness, or pain in the legs. In very rare cases, more significant nerve injury may occur. Dr. Kazarian uses specialized techniques and monitoring to minimize this risk.
Hardware Failure
The interbody implant, posterior pedicle screws, rods, or other hardware used to stabilize the spine can occasionally loosen, shift, or break before the fusion has fully healed. The precision of robotic-guided screw placement helps minimize this risk by ensuring optimal screw positioning, but if hardware complications do occur, additional surgery may be needed to replace or adjust the affected components.
Nonunion (Pseudarthrosis)
In some cases, the bone may not fully fuse as expected, a condition called nonunion or pseudarthrosis. This can cause persistent or recurring pain and instability. Factors such as smoking, diabetes, and poor nutrition can increase this risk. If nonunion occurs, a revision surgery may be recommended.
Need for Additional Surgeries
While spinal fusion is often successful, there is a possibility that additional surgeries may be needed in the future. This could be due to nonunion, hardware issues, adjacent segment disease, or other factors. Dr. Kazarian will discuss your individual risk factors with you.
Retrograde Ejaculation
In male patients, the anterior approach passes near nerves that control ejaculatory function. There is a small risk that these nerves may be affected, which can cause semen to travel backward into the bladder instead of forward during ejaculation. This does not affect the ability to achieve an erection or orgasm, but it can impact fertility. Dr. Kazarian will discuss this risk with you in detail.
Major Vascular Injury
The anterior approach requires working near the large blood vessels (aorta and vena cava) in front of the spine. While rare, there is a risk of injury to these vessels during surgery. A vascular surgeon is often present or available during the procedure to help manage this risk and ensure the safest possible approach.
Common questions
What is the difference between an anterior and a posterior approach to lumbar fusion?
In an anterior approach (ALIF), Dr. Kazarian accesses the spine through a small incision in the lower abdomen, working from the front of the body. In a posterior approach, the incision is made in the back, and the surgeon works around the spinal muscles and nerves to reach the disc space. The anterior approach offers the advantage of leaving the back muscles completely undisturbed and allows placement of a larger implant for better support and spinal curvature restoration. ALIF is typically combined with posterior robotic percutaneous pedicle screws placed through small incisions in the back to provide additional stability while the fusion heals. Dr. Kazarian will recommend the approach that is best suited to your specific condition and spinal anatomy.
Where exactly is the incision, and how large will it be?
The incision for the anterior portion of ALIF is made in the lower abdomen, typically a horizontal or slightly oblique cut below the belly button. It is usually three to five inches in length, though the exact size depends on factors such as the number of spinal levels being treated and your body type. The abdominal muscles are separated along their natural fiber lines rather than cut, which helps with healing. Additionally, small incisions are made in the back for the posterior robotic percutaneous pedicle screws. All incisions are closed with dissolvable sutures or surgical staples and typically heal into thin, subtle scars over time.
Why is a vascular surgeon involved in this spine surgery?
The major blood vessels of the body, including the aorta and vena cava (or the iliac arteries and veins), run directly in front of the lumbar spine. To safely reach the disc space from the front, these vessels must be carefully identified and gently moved aside. A vascular surgeon or specialized access surgeon performs this part of the procedure because they have extensive training and experience in handling these critical structures. Their involvement significantly reduces the risk of vascular injury and ensures the safest possible access to the spine for Dr. Kazarian.
How long does the ALIF procedure take?
Anterior lumbar interbody fusion with posterior robotic percutaneous pedicle screws typically takes between two and four hours, depending on the number of spinal levels being fused and the complexity of your individual anatomy. The procedure involves two stages: the anterior portion (performed through the abdomen with a vascular surgeon) and the posterior portion (placement of robotic pedicle screws through small incisions in the back). You should plan to be at the hospital for the entire day of surgery, including pre-operative preparation and initial recovery time in the post-anesthesia care unit.
What kind of pain should I expect after surgery, and how is it managed?
After ALIF, you may experience soreness at the abdominal incision site and some residual discomfort in the lower back from the posterior screw placement. Many patients report that their preoperative leg pain is significantly reduced or gone immediately after surgery. Abdominal soreness, mild bloating, and temporary changes in appetite are common in the first one to two weeks due to the surgical approach through the abdomen. Dr. Kazarian will send you home with the following medications as needed: • Tylenol (acetaminophen) 500–1000 mg every 6 hours for mild pain • Flexeril (cyclobenzaprine) 5 mg every 6 hours for muscle spasms or soreness • Oxycodone 5–10 mg every 4–6 hours for moderate to severe pain not controlled by Tylenol alone Ice therapy and frequent short walks also help reduce pain and swelling. Most patients are able to gradually wean off prescription pain medications within four to six weeks and transition to over-the-counter options.
What is the overall recovery timeline after ALIF?
Recovery from anterior lumbar interbody fusion is a gradual process that occurs in stages. Most patients spend one to three days in the hospital after surgery. The first two weeks at home are focused on managing pain, protecting the surgical site, and gradually increasing walking distance. Many patients notice improvement in their symptoms within the first few weeks. By six weeks, most patients experience significant improvement and should be weaning off of most pain medications. Bending, twisting, and lifting restrictions are in place for the first six weeks. At the six-week mark, most patients are performing activities of daily living, physical therapy begins, and activity increases gradually from there. The bone graft takes approximately six to twelve months to fully fuse into solid bone, and Dr. Kazarian will monitor fusion progress with periodic imaging at your follow-up appointments.
What are the potential risks and complications of ALIF?
As with any surgical procedure, ALIF carries some risks. General surgical risks include infection, bleeding, blood clots, and reactions to anesthesia. Risks specific to the anterior approach include potential injury to the major blood vessels near the spine, which is why a vascular surgeon assists during the procedure. Temporary ileus, a condition where bowel function is temporarily slowed, can occur due to the abdominal approach but usually resolves within a few days. Other possible complications include retrograde ejaculation in male patients (a rare risk related to nerve disturbance near the spine), nerve injury, hardware complications such as screw loosening or rod breakage, nonunion (pseudarthrosis), and adjacent segment disease. Your surgical team takes extensive precautions to minimize these risks, and serious complications are uncommon.
Will the screws and hardware stay in my spine permanently?
In the vast majority of cases, the titanium screws, rods, and interbody cage remain in your spine permanently and do not need to be removed. Titanium is biocompatible, meaning your body tolerates it very well, and the hardware is designed to last a lifetime. Once the bone has fully fused (typically within six to twelve months), the screws and rods serve a secondary role since the solid bone fusion itself provides the primary stability. In rare cases, hardware may need to be removed if it causes persistent discomfort, becomes loose, or if an infection develops around it. The hardware is safe for most MRI scans, though you should always inform any medical provider that you have spinal implants. You will receive an implant card with details about your specific hardware for your records.
Will I need to wear a back brace after surgery?
Dr. Kazarian requires a lumbar brace (also called a lumbar orthosis or LSO) to be worn for six weeks after fusion surgery. The brace should be worn as much as possible during this period, as it provides external support to the healing spine, limits excessive bending and twisting, and serves as a helpful reminder to maintain good posture and body mechanics. In some cases, Dr. Kazarian may also prescribe a bone stimulator to help promote fusion healing. It is important to wear the brace exactly as directed, as consistent use during the first six weeks supports the best possible outcome.
What role does physical therapy play in recovery from ALIF?
Physical therapy is a critical component of your recovery and plays a major role in achieving the best possible outcome. Therapy typically begins at six weeks after surgery, once your incision has healed and Dr. Kazarian gives clearance. Early sessions focus on gentle core activation, posture training, and safe body mechanics for daily activities such as sitting, standing, and walking. As healing progresses, your therapist will introduce progressive core strengthening, flexibility exercises, and functional training tailored to your goals. Most patients attend physical therapy two to three times per week for two to four months. A home exercise program will also be prescribed for you to perform on the days between therapy visits. Consistent participation in physical therapy helps rebuild the muscular support around your spine, improves mobility, and reduces the risk of future problems.
When can I drive again after ALIF surgery?
Most patients are cleared to resume driving approximately six to eight weeks after ALIF surgery, though this timeline can vary based on your individual recovery, the number of levels fused, and Dr. Kazarian's assessment. You should not drive while taking any narcotic or sedating pain medications, as they impair your reaction time and judgment. Before resuming driving, you should be able to sit comfortably for at least 20 to 30 minutes, move your foot quickly and confidently between the gas and brake pedals, and check your mirrors by turning your upper body without significant pain. Dr. Kazarian will let you know when it is safe to get back behind the wheel. For the first few drives, consider starting with short trips in low-traffic areas to rebuild your confidence.
When can I go back to work after ALIF?
Your return-to-work timeline depends primarily on the physical demands of your occupation. Patients with sedentary or desk-based jobs can often return to work within four to six weeks, initially on a part-time or modified-duty basis if possible. Jobs requiring light physical activity such as occasional walking or standing may require eight to twelve weeks of recovery. Occupations involving moderate to heavy lifting, prolonged standing, bending, or manual labor typically require three to six months before a safe return, and Dr. Kazarian may recommend a gradual return-to-duty program. Your surgical team can provide work restriction documentation for your employer and will clear you for progressive increases in activity at each follow-up visit based on your healing progress.
How long does it take for the bone fusion to fully heal?
The bone graft in an ALIF typically takes six to twelve months to mature into solid, fully healed bone, though the exact timeline varies from patient to patient. Early signs of fusion are often visible on X-rays by three to four months, but solid bridging bone throughout the entire graft site generally requires nine to twelve months. Factors that influence fusion healing time include your age, nutritional status, bone density, whether you use tobacco products (which significantly impairs bone healing), and the number of levels fused. Dr. Kazarian will monitor fusion progress with periodic imaging at your follow-up appointments. It is important to understand that while you will feel progressively better during this time, the biological process of bone fusion continues working beneath the surface for many months. Following your activity restrictions and avoiding smoking are two of the most important things you can do to support successful fusion.
What is Dr. Kazarian's training and background?
Dr. Kazarian completed his undergraduate education at Princeton University and earned his medical degree from the University of Michigan Medical School. He completed his orthopaedic surgery residency at Harvard Medical School and Massachusetts General Hospital, followed by a fellowship in spine surgery at the Mayo Clinic.
Conditions treated
Degenerative Disc Disease
Degenerative disc disease describes age-related wear of the spinal discs that can lead to chronic neck or back pain and contribute to other spine problems including herniations, stenosis, and instability.
Spondylolisthesis
Spondylolisthesis is a condition in which one vertebra slips forward over the one below it, sometimes producing back pain, leg pain, and instability, though many patients have minimal or no symptoms.
Spinal Stenosis
Spinal stenosis is a narrowing of the spinal canal that compresses the spinal cord or nerve roots, producing leg pain, walking limitation, and, in cervical cases, hand and balance problems.
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This page is for general education and is not medical advice. Whether this procedure is right for you depends on your anatomy, imaging, and goals, and is decided together at an in-person consultation.
