What is Anterior Lumbar Interbody Fusion (ALIF)?

From the Guidelines

Anterior Lumbar Interbody Fusion (ALIF) is a surgical procedure where an anterior approach is used to remove a damaged disc between two vertebrae and replace it with a bone graft or implant to promote fusion of the vertebrae, providing a durable and physiologically dynamic support system that protects neural structures and decreases mechanical pain. This technique involves approaching the spine from the front (anterior) through an incision in the abdomen, which poses less morbidity to the patient in terms of muscle manipulation and wound healing, as noted in the 2016 IDSA clinical practice guideline for the treatment of coccidioidomycosis 1. The key aspects of ALIF include:

• Removing the entire disc and surrounding bones, even if complete corpectomy is required, to ensure a thorough removal of the infected or damaged tissue
• Using autologous bone, harvested from the iliac crest or the ribs, as graft material, which is probably the best option whenever possible, according to the same guideline 1
• Considering the patient's general medical condition, which can affect the duration of the fusion maturation process and the quality of the bone used for grafting The goal of ALIF is to stabilize the spine, relieve pressure on nerves, and reduce pain, ultimately improving the patient's quality of life and reducing morbidity and mortality associated with spine conditions.

From the Research

Definition and Overview of Anterior Lumbar Interbody Fusion (ALIF)

• Anterior Lumbar Interbody Fusion (ALIF) is a surgical approach for interbody fusion in the lumbar spine, providing access to the disc space and allowing for the release of the anterior longitudinal ligament and insertion of a large, lordotic interbody graft 2.
• ALIF is used to treat various lumbar degenerative pathologies, including degenerative disk disease, spondylolisthesis, recurrent disk herniation, adjacent level disease, pseudoarthrosis, and to restore sagittal balance 3.

Indications and Techniques

• ALIF can be an extremely useful tool in any spine surgeon's armamentarium, but proper patient selection is key to success 3.
• The procedure involves the use of interbody cages with integrated screws, which has increased the arthrodesis rate and improved clinical outcomes while decreasing morbidity and operative time 3.
• Stand-alone ALIF may be a suitable surgical option in carefully selected patients, providing good clinical results and adequate fusion rates without the need for posterior instrumentation 3.

Patient Selection and Pre-operative Workup

• Patient selection criteria for ALIF include patient age, sex, bone density, body mass index, nicotine usage history, medical comorbidities, anatomy of the distal iliac vein/abdominal aorta/iliac bifurcation/iliocaval confluence, history of prior abdominal surgery/infection/radiotherapy, surgical goals, operative level, and availability of approach co-surgeons 2.
• Pre-operative workup for ALIF procedures should include magnetic resonance imaging of the lumbar spine, standing X-rays of the lumbar spine with flexion/extension views, scoliosis or long-cassette spinal X-rays, computed tomography of the lumbar spine without contrast, and a dual-energy X-ray absorptiometry scan 2.

Complications and Outcomes

• ALIF is associated with a number of unique complications, including vascular, abdominal, and neurological complications 2, 4.
• The morbidity rates for ALIF vary depending on the preoperative diagnosis, with spondylolisthesis and spinal stenosis associated with significantly higher overall morbidity odds compared to lumbar disc degeneration 4.
• Single Position Lateral Anterior Lumbar Interbody Fusion (SPL-ALIF) has demonstrated significant reductions in operative time, blood loss, and postoperative ileus, with equivalent radiographic outcomes compared to traditional supine ALIF 5.

Bone Graft Substitutes

• Bone graft selection is critical for achieving solid arthrodesis of the degenerative spinal segment in ALIF procedures 6.
• Iliac crest bone grafts (ICBG) remain the "gold standard" for achieving lumbar fusion, but alternatives such as autografts, allograft-based, synthetic, and cell-based technologies are being explored due to donor site morbidity and finite supply of ICBG 6.