Anterior Lumbar Interbody Fusion (ALIF) Animation

This video animation reveals how an intervertebral disc weakened by degenerative disc changes or injury (eg, herniation) may lead to back and/or leg pain and how an anterior lumbar interbody fusion (ALIF) procedure treats this problem.

What is an ALIF procedure?

ALIF is a type of spinal surgery to help relieve low back and leg pain. The spine surgeon removes a damaged disc from the low back (lumbar spine) and replaces it with a specially made implant called an interbody device or cage. The video also unmasks what a surgeon’s anterior (from the front of the body) approach looks like, and demonstrates how a bone graft filled interbody device helps the spine fuse.
Doctor in operating room, setting up surgical lamp.Anterior lumbar interbody fusion (ALIF) may be performed in a hospital's operating room or an ambulatory surgery center (ASC, outpatient). Photo Source:

Why are intervertebral discs important?

Among the spine’s most important structures are its 23 discs—each intervertebral disc in the cervical, thoracic and lumbar spine is situated between an upper and lower vertebral body. The discs not only cushion the spine during movement, such as when you walk or jump, but also separate the vertebrae and provide sufficient room for nearby spinal nerve roots.

What types of problems affect discs in the low back?

There is some evidence that the disc itself can cause pain; this is referred to as discogenic pain. Discs can weaken or even break open (rupture, herniate) as a result of degenerative changes associated with aging or other causes, such as injury. In some cases of degenerative disc disease, the cellular structure of a disc may change over time. A disc may lose height as it flattens or the disc’s outer wall (ie, annulus) that encases its gel-like center (ie, nucleus) may tear or break open allowing the nucleus to ooze out and compress spinal nerve roots. Symptoms may include low back pain that spreads into one or both buttocks and legs with numbness, tingling and sometimes, weakness.

Sometimes, a stress fracture, infection or spine-related disorder allows one vertebral body to slide forward over the vertebrae beneath it; a spinal disorder called spondylolisthesis. Spondylolisthesis can develop gradually or suddenly and puts pressure on nearby nerve roots. An ALIF procedure may be recommended to help stabilize the “vertebral slip” by removing the intervertebral disc and performing instrumentation and fusion. Surgery involves implanting interbody devices into the empty disc followed by rods and screws that quickly stabilize the spine. Bone graft is packed into and around the devices and instrumentation to stimulate bony healing called fusion.

Anterior Lumbar Interbody Fusion Explained

Unlike other types of spine surgery where the procedure is performed from the back of your spine, the word anterior in this procedure’s name means the surgeon gains accesses to your spine from the front of your body through an abdominal incision.

The anterior approach allows the surgeon to better see and remove the disc without cutting through spinal muscles. However, organs and vessels do come between the surgeon and the spine when approaching from the front, so the spine surgeon usually teams up with a vascular surgeon who specializes in knowing how to maneuver around organs and part the curtain of blood vessels, including the aorta and vena cava, to spotlight the troubled disc.

The size of the abdominal incision depends on whether the surgery is performed as a traditional open or minimally invasive procedure. In open spine surgery, the incision is large enough that the surgeon can use regular-sized instruments to perform the procedure. However, in minimally invasive surgery, the surgical incision is small, and the surgery may be performed through small tubes and tools that separate soft tissues, cut and grab. Minimally invasive spine surgery is known for less blood loss, decreased post-operative pain, faster healing and minimal scarring.

ALIF Procedure Step By Step

After accessing the precise level of the lumbar spine, the first step is to remove the damaged disc, disc material or tissue pushing on the spinal canal (eg, cauda equina) or nerve roots. This step is called a lumbar discectomy. To identify the correct disc for removal, the surgeon inserts a special surgical needle into the disc and a real-time x-ray is taken for verification purposes. Next, the surgeon removes the disc and prepares the empty disc space for implantation of the interbody devices or cages. A spinal cage is typically hollow in the center and filled with bone graft to stimulate new bone growth. Bone graft promotes spinal fusion, a process where the vertebrae above and below are joined as fusion heals.

What’s the difference between autograft and allograft?

Autograft and allograft are two types of bone material that may be used in spinal fusion procedures. Autograft is taken from the iliac crest of one or your hip bones. While autograft may be a good choice for some patients, acquiring the bone requires a separate surgery to “harvest” your bone. The drawback is harvesting autograft comes with surgical risks, such as infection, bleeding, and nerve damage. Some patients find the hip harvest site to be more painful than the lumbar surgery itself.

Allograft may be an option for some patients. This is donor or banked bone graft. There can be a risk of infection using allograft too.

Whether your surgeon uses autograft, allograft or both, the graft material is packed inside the interbody devices/cages. Screws and rods help secure the interbody cages into the empty disc and help stabilize the operative level during bony healing (fusion).

Hospital or Outpatient Post-Operative Recovery

Depending on the complexity of your spinal problem and your health, your ALIF procedure may be performed in an outpatient or ambulatory surgery center (ASC) sometimes called same day surgery. Your surgeon may recommend your surgery be performed at the hospital with an overnight or longer stay. Whether you have surgery in an ASC or are hospitalized, some post-operative steps are the same: managing post-op pain, getting up and walking soon after surgery (eg, same day) and resuming a normal diet.

Your surgeon may prescribe a back brace for your comfort and spine protection. Discharge and home recovery instructions outline use of medication, resuming a regular diet, and activity restrictions, which may include when you can return to work. To help ensure a successful solid fusion, you should not smoke, vape or use tobacco as nicotine is toxic to new bone growth.

Updated on: 02/15/19
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