What is involved in a Transforaminal Lumbar Interbody Fusion (TLIF) procedure?

Transforaminal Lumbar Interbody Fusion (TLIF) Procedure

TLIF is a surgical technique that provides excellent access to the disc space through a unilateral approach with minimal neural retraction, allowing for decompression, interbody fusion, and segmental stabilization for various degenerative lumbar spine conditions. 1

Indications for TLIF

• Degenerative disc disease with instability
• Low-grade spondylolisthesis (grade I)
• Spinal and foraminal stenosis
• Recurrent disc herniation requiring fusion
• Symptomatic unremitting low back pain or radiculopathy that has failed conservative management 2

Preoperative Considerations

• Patients must fail at least 6 weeks of conservative therapy before surgical intervention 2
• Preoperative imaging (MRI, CT) to confirm segmental instability and pathology
• Medical comorbidities should be addressed during preoperative clearance 2

Surgical Technique

Patient Positioning and Setup

• General anesthesia
• Patient positioned on a radiolucent table to allow intraoperative fluoroscopy
• Prone position with abdomen free to reduce venous pressure 1

Approach

1. Incision and Exposure:

   • Small incisions over the vertebral levels of interest
   • Utilization of tubular dilators (fixed or expandable) seated against the facet joint complex 1

2. Decompression:

   • Unilateral laminectomy and inferior facetectomy at the fusion level
   • Visualization of the ipsilateral neural elements 1, 3
   • For central stenosis, decompression should extend medially to visualize dura mater to the contralateral pedicle 1

3. Disc Space Preparation:

   • Complete discectomy through the vertebral foramen
   • Careful preparation of endplates while avoiding injury to prevent cage subsidence 1
   • Kambin's triangle must be fully visualized before facetectomy 1

4. Interbody Device Placement:

   • Insertion of one or two titanium cages or a banana-shaped allograft spacer
   • Cages packed with autologous bone (often from the facetectomy) 1, 4
   • Additional local autograft placed behind the spacer 4

5. Posterior Instrumentation:

   • Placement of bilateral pedicle screws and rods for fixation
   • Decortication of remaining laminae and contralateral facet joint
   • Additional bone graft placement posterolaterally 4

Advantages of TLIF

• Less blood loss compared to open procedures 1
• Reduced postoperative pain 1
• Shorter hospital length of stay 1
• Minimizes nerve root retraction compared to PLIF 5
• Excellent exposure with minimal risk, particularly in revision cases 3
• Avoids anterior approach complications associated with ALIF 3
• Shorter operative times compared to PLIF 5
• Lower nerve irritation rates compared to PLIF 5

Limitations and Disadvantages

• Less effective for substantial spinal deformity or high-grade spondylolisthesis 1
• Increased intraoperative fluoroscopy time compared to open procedures 1
• Learning curve affects operative time initially 1
• Higher complication rates (31%) when combined with posterior approaches (360° fusion) compared to posterolateral fusion alone (6%) 2

Postoperative Care

• Ambulation typically begins around 2-3 days postoperatively 3
• Pain management with appropriate analgesics
• Fusion rates are excellent (92-94% in reported studies) 3, 4
• Significant improvements in pain and function can be expected 2

Complications to Monitor

• Transient neurological complications (rare)
• Dural tears
• Infection
• Hardware failure
• Pseudarthrosis
• Adjacent segment disease

Key Technical Pearls

• Protect exiting and traversing nerve roots with small cottonoids and gentle retraction 1
• Bone removed during facetectomy can be utilized as autograft for the interbody cage 1
• Avoid removing pedicle bone during decompression 1
• Confirm correct placement of interbody device with intraoperative fluoroscopy 1
• If using bone morphogenic protein, avoid packing too much posteriorly to prevent nerve irritation 1

TLIF has demonstrated excellent clinical outcomes with high patient satisfaction rates and solid fusion rates in multiple studies, making it a reliable and safe technique for treating various degenerative conditions of the lumbar spine 3, 6.