eXtreme Lateral Interbody Fusion (XLIF)

About Back Pain

An estimated ten million adults suffer from chronic back pain annually, in the United States The majority of patients suffer spine problems related to degenerative conditions. These degenerative conditions can result in instability and intrusion into the spinal cord and surrounding nerves, causing back pain and/or radiating pain in the arms or legs.

Non-surgical Treatments for Back Pain

When a patient is experiencing back pain, diet and exercise are often the initial treatment choices. Bed-rest, medication, physical therapy, chiropractic care and steroid injections are used if a patient does not see any results from a change in their lifestyle. Medication provides only temporary relief from extreme back pain, as back pain typically returns once drug therapy is stopped. The majority of back patients show improvement with these treatments. However, when nonsurgical treatments are not effective, some patients require spine surgery. It is estimated that over one million patients undergo spine surgery each year in the U.S. Traditional spine surgery requires large incisions which increases recovery time and lengthens return to normal activity.

NuVasive® Creative Spine Technology® – The Surgical Solution

NuVasive has developed a portfolio of products designed to allow surgeons to use traditional surgical techniques with a minimally invasive approach. By reducing the amount of soft tissue disruption without requiring surgeons to dramatically alter their procedures, clinical outcomes are comparable to traditional open procedures, while patient recovery times are significantly reduced. NuVasive’s innovative technologies enable surgeons to perform a variety of complicated spine procedures through a minimally disruptive procedural approach. Because NuVasive’s products cause less tissue disruption during the surgical approach, patients typically have shorter hospital stays and quicker recovery times. Patients are often walking hours after surgery. NuVasive’s proprietary technology includes the surgical instruments that provide access to the surgical site, while other instruments pass through it. The MaXcess® retractor utilizes a split-blade design that allows maximum access and visualization to the spine, while minimizing the damage to surrounding tissue. Other unique instrumentation includes the NeuroVision® JJB nerve monitoring system which provides an added level of nerve safety during minimally disruptive spine surgery. NuVasive also offers advanced fixation products to stabilize the spine during spine fusion.

NuVasive has developed the XLIF® (extreme lateral interbody fusion) surgical approach. The procedure approaches the spine from the side rather than from the front or back. This approach allows for less painful postoperative recovery as less muscle tissue is disrupted during surgery.


The Procedure

In an XLIF procedure, the spine is approached from the side of the body. The patient is positioned on the surgical table on his side. Two small incisions are made: one directly over the side of the waist (through which most of the procedure is performed), and the other slightly behind the first, toward the back muscles (through which the surgeon’s finger safely guides the approach).

Until now, widespread acceptance of minimally invasive techniques has evaded spine surgery. The primary reason for this was the inherent difficulty introducing new technologies while attempting to achieve the same surgical objectives as conventional surgery. The XLIF surgical technique is different, however, because it incorporates two systems developed by NuVasive®: the MaXcess® System and the NeuroVision® JJB System. NuVasive has also developed other products to support the XLIF procedure, such as the XLPTM Lateral Plate, the SpheRx® DBR® II System, and the CoRoent® XL device.

XLIF Patient Benefits

Reduced operative time – Traditional procedures can take many hours to perform; the XLIF procedure can be successfully completed in as little as one hour, reducing the amount of anesthesia time. Reduced blood loss and minimal scarring – The MaXcess® retractor dilates the tissue rather than cutting, resulting in much less trauma to the affected area.

Reduced post operative pain – The XLIF procedure does not require entry through sensitive back muscles, bones, or ligaments, so patients are usually walking the same day.

Reduced hospital stay – XLIF requires only an overnight stay in the hospital, compared to several days of immobility and hospitalization typical of traditional open approaches.

Rapid return to normal activity – Patients are usually walking the same day after surgery and recovery is typically around 6 weeks, compared to 6 months or more.


XLIF Indications

The XLIF minimally disruptive procedure can be performed for a number of situations. The list below contains representative examples. The list is not intended to include all possible indications/and or contraindications.

Any thoracolumbar case above L5-S1 requiring access to the disc space and/or vertebral bodies.

Examples include:

  • DDD with Instability
  • Recurrent Disc Herniation
  • Degenerative Spondylolisthesis (≤ grade 2)
  • Degenerative Scoliosis
  • Pseudarthrosis
  • Discitis, Vertebral Osteomyelitis (without active infection)
  • TDR Revision
  • Post-Laminectomy Instability
  • Junctional Disease

XLIF Contraindictations

Any generally accepted contraindication to fusion, such as:

  • Systemic infection
  • Osteoporosis
  • Significant co-morbidities

XLIF-specific contraindications:

  • L5-S1
  • Lumbar deformities with > 30° rotation
  • Degenerative spondylolisthesis grade 3
  • Bilateral retroperitoneal scarring (e.g., abscess or prior surgery)
  • Need for direct posterior decompression through same approach
    (Second posterior micro-decompression not contraindicated)

MaXcess® System

pic-xlifThe MaXcess System provides customized maximum surgical access while minimizing the soft tissue disruption that often occurs during open surgery. As opposed to minimal access systems, which provide minimal spinal access, minimal visualization, and minimal surgical confidence, the MaXcess System from NuVasive® offers improved visualization, and increased angulation and positioning of instruments and implants. This provides the surgeon all the benefits of a minimally disruptive surgical approach without compromising conventional surgical techniques.

The MaXcess System allows the fundamentals of conventional surgical techniques to be achieved, while eliminating the unfamiliar requirements of operating coaxially through tubular portals. Additionally, since there are no adjunctive visualization tools (e.g., endoscope, monitor), the MaXcess System enables direct illuminated visualization of the patient’s anatomy through conventional methods.

NeuroVision® JJB System

The NeuroVision JJB Nerve Monitoring System is a technologically advanced intraoperative nerve monitoring system that assists the surgeon with safe implant placement and surgical technique by monitoring the patient’s nerve activity throughout the surgical procedure.

pic-xlif2Electromyography (EMG), the study of the electrical activity of muscles, is used during the XLIF procedure to determine the health and function of nerves, particularly in cervical or lumbar spine surgeries where nerve roots are affected.

The NeuroVision System combines intraoperative electrically stimulated EMG and spontaneous EMG activity to assess possible nerve root irritation or injury during surgery. Software algorithms help provide the surgeon with real-time data to assist with patient nerve safety.

Monitoring the muscles requires the placement of adhesive needle electrodes on or under the skin overlying the patient’s leg muscles. These electrodes record muscle activity during the procedure, providing information about the health and function of the specific spinal nerves that indicate muscle activity and sensation functions to them.

The NeuroVision System’s automated features allow it to seamlessly integrate into the surgical technique while providing accurate and reproducible real-time feedback about nerve health and function. The system allows the surgeon to have first-hand knowledge of the monitoring results, confirming the safe progression of the XLIF surgical procedure.

XLPTM Lateral Plate

pic-xlif3NuVasive’s objective in developing the XLP lateral plate was to provide a simple yet reliable method of internal fixation delivered through a single XLIF approach. XLP lateral plate fixation allows a surgeon to preserve the minimally invasive benefits of a stand-alone XLIF procedure while providing effective stabilization to the interbody implant. Through clinical evaluation and system refinement, NuVasive® has designed each component of the XLP platform to work seamlessly with the MaXcess® retractor and the XLIF approach, resulting in an efficient system.

XLP fixation adds only a few minutes to the XLIF procedure, but saves valuable operating room time by eliminating the need to reposition the patient prior to instrumentation.

The XLP lateral plate is a significant advancement in the evolution of the XLIF approach that provides measurable benefits to the patient, hospital, and surgeon. This single-approach procedure provides a number of benefits, including:

  • A safe, reproducible approach
  • Decreased operative time
  • Shortened hospital stay
  • Quicker patient recovery and return
    to normal activity

SpheRx® DBR® II System

pic-xlif4The SpheRx DBR II Minimally Disruptive Fixation System offers a solution for performing effective minimally disruptive spinal fixation in a simple, straightforward manner. Seamless, step-by-step integration of NeuroVision® nerve monitoring provides real-time feedback throughout the surgery and helps to ensure safe hardware placement and neural integrity. Additionally, the spherical end of the SpheRx DBR II rod fits precisely into the screw head, leaving no residual rod overhang at the superior end of the construct. This reduced implant profile may minimize the incidence of hardware-related, adjacent level symptoms.

CoRoent® XL

pic-xlif5CoRoent XL is an anterior column reconstruction device sized for stability, anatomically shaped, and designed for simplicity. Its large, anatomical shape provides maximum surface area and structural stability, and its large apertures allow bony through-growth. CoRoent XL’s radiolucent PEEK-OPTIMA® material provides optimal stiffness compatibility with the surrounding bone, and its titanium markers enable easy-tointerpret placement and orientation verification.

CoRoent XL has multiple length options to ensure optimal apophyseal support, reducing the chance of subsidence. Additionally, it’s available in lordotic profiles to induce proper sagittal alignment.

Frequently Asked Questions

Why might a doctor recommend spine surgery?

There are a number of reasons why a doctor might recommend spine surgery. In general, surgery is performed to eliminate instability or nerve compression in the back due to degenerated discs and/or facet joints. Disc degeneration results in a lack of proper spacing between the discs, which can cause severe and debilitating pain. Other conditions that might require surgery are the slippage of one vertebra over another or a change in the normal curvature of the spine – including scoliosis and other extreme curvatures of the spine.

What is disc degeneration?

As we age, our intervertebral discs lose water content and become less able to hold the loads applied to them. This aging process is normal, but in some people, it can cause back or leg pain due to loss of disc height and impingement of nerves. Many people suffer a compromised quality of life due to disc degeneration. Spinal surgery can reduce motion between the vertebrae, correct alignment, and restore proper disc height, alleviating pain. During the procedure, the surgeon removes most of the disc between the two vertebrae that are to be stabilized and implants a spacer to restore correct spinal alignment. The surgeon also implants bone-forming cells that bridge the space between the vertebrae and allow the bone to grow together. Increased stability and restoration of disc height often result in significant pain relief.

What is lumbar interbody fusion?

Lumbar interbody fusion is a surgical technique that attempts to eliminate instability in the back. Instability can be due to degenerated discs and/or facet joints that cause unnatural motion and pain, loss of height of the disc space between the vertebrae that causes pinching of the spinal nerves exiting the spinal canal, slippage of one vertebra over another, and/or change in the normal curvature of the spine.

How is fusion performed?

Fusion is accomplished by fusing the vertebrae together to reduce their motion. Fusing the vertebrae together requires removal of most of the intervertebral disc (or discs if more than one level is identified for fusion), preparation of the adjacent ends of the vertebrae (endplates) to clear the soft tissue, implantation of an intervertebral spacer to restore disc height and spinal alignment (for nerve root decompression) and to carry the loads of the torso, and packing the vertebrae with bone-forming cells that will bridge the space and fuse the joint. In some cases, the instability is severe enough that further augmentation of the fusion is required by placing screws and plates or rods into the vertebrae to hold them together.

What are the treatment options for fusion?

In most cases, some attempt is made at conservative treatment before fusion is recommended. If fusion surgery is warranted, there are several techniques for approaching the spine to perform the fusion, defined mainly by the direction of the approach.

Three of the most traditional approaches to spinal fusion include:

Posterior Lumbar Interbody Fusion (PLIF)

In a PLIF procedure, the spine is approached from the back of the body, allowing for direct access to problematic nerves and potential placement of screws and rods in addition to the intervertebral fusion through one approach. The muscles lying over the spine are opened and spread from the middle out to both sides. Some vertebral bone is removed, relieving pressure on the nerves and providing access to the intervertebral disc. Traditionally, this approach requires significant muscle, bone and ligament dissection and/or disruption, which can sometimes lead to pain and desensitization of the back muscles after surgery.

Transforaminal Lumbar Interbody Fusion (TLIF)

A traditional TLIF procedure is essentially a modification of a PLIF procedure where the muscle is dissected from the middle out to the side, but only on one side instead of from the middle out to both sides (as in PLIF) sparing trauma to the opposite side.

Anterior Lumbar Interbody Fusion (ALIF)

In an ALIF procedure, the spine is approached from the front of the body. Spine surgeons and general surgeons often work together to safely expose the front of the spine either by going through the abdomen or by retracting it under the skin. This approach spares trauma to the back muscles, but requires delicate manipulation of major blood vessels that lie in front of the spine.

What is lateral access spine surgery?

Lateral access spine surgery is a safe and reproducible means of addressing certain spine disorders with an approach from the side of the patient, as opposed to an approach from the back or the front. A lateral approach is made safe with the use of nerve monitoring technology.

What is eXtreme Lateral Interbody Fusion (XLIF)?

In an XLIF procedure, the spine is approached from the side of the body. The patient is positioned on the surgical table on his side. Two small incisions are made: one directly over the side of the waist (through which most of the procedure is performed), and the other slightly behind the first, toward the back muscles (through which the surgeon’s finger safely guides the approach).

Is XLIF a widely adopted surgical technique?

Until now, widespread acceptance of minimally invasive techniques has evaded spine surgery. The primary reason for this was the inherent difficulty introducing new technologies while attempting to achieve the same surgical objectives as conventional surgery. The XLIF surgical technique is different, however, because it incorporates two systems developed by NuVasive®: the MaXcess® System and the NeuroVision® JJB System.

How do NuVasive® systems contribute to the success of the XLIF technique?

The MaXcess® System provides customized maximum surgical access while minimizing the soft tissue disruption that often occurs during open surgery. The MaXcess System allows the fundamentals of conventional surgical techniques to
be achieved, while eliminating the unfamiliar requirements of operating coaxially through tubular portals. Additionally, since there are no adjunctive visualization tools (e.g., endoscope, monitor), the MaXcess System enables direct illuminated visualization of the patient’s anatomy through conventional methods.

The NeuroVision® JJB System is another important technology that enables safety and reproducibility during minimally disruptive techniques. This system is the only surgeon-driven technology that provides dynamic, discrete information about nerve location and condition. In the XLIF technique, NeuroVision is used to enable a safe trajectory past the nerves in the psoas muscle by communicating nerve proximity and directional information. This enables the surgeon to locate and avoid the lumbar plexus while accessing the disc. NeuroVision is the only nerve avoidance system that has demonstrated safety and reproducibility during a lateral transpsoas technique.

What are the key advantages to the XLIF technique?

The XLIF approach does not require dissection or retraction of the sensitive back muscles, bones, ligaments, or nerves and allows for more complete disc removal and implant insertion as compared with traditional posterior procedures. Nor does lateral access require the delicate abdominal exposure or present the same risk of vascular injury as traditional anterior approaches. As a result, operating time is often reduced, patient blood loss is minimized, and recovery time is significantly shorter.

Are there any disadvantages to the XLIF surgical technique?

The primary disadvantage of the XLIF approach is the inability to directly address problems with nerves toward the back of the spine, which would require a second procedure, if necessary. In postoperative studies, thigh discomfort was routine, and slight lateral thigh numbness is rare. However, both symptoms resolved completely within four to six weeks. Some patients may experience some soreness at the surgical incision and/or pain or weakness when lifting the thigh immediately after surgery.

What can a patient expect after XLIF surgery?

Most patients stay in the recovery room from one to three hours after surgery. Once the anesthesiologist feels that the patient is doing well, he will be returned to his room in the hospital. It is normal for incision wounds to be sore immediately after surgery. The nursing staff will regularly check vital signs and ensure there is no problem with either the wound or nerve function in the patient’s legs. Generally, most patients are able to get up and walk around the evening after surgery. Most XLIF patients are discharged from the hospital the day following surgery. The physician will discuss with the patient any appropriate medications, as well as a prescribed program of activities.

Generally, fusion patients are seen again in the physician’s office about ten days to two weeks after surgery. After the initial follow-up, a patient will need to visit with his doctor at various intervals (up to two years or more) to assess fusion progress.