Transforaminal Lumbar Interbody Fusion (TLIF): Indications

1. Degenerative disc disease with a specific discogenic pain pattern.

2. Low grade 1 or grade 2 spondylolisthesis.

3. Instability of the anterior column in association with posterior pathology.

4. Fixation across the lumbosacral junction (lumbar/sacrum) especially with long segment fusion or when a 360-degree fusion is desired.

5. Some of the more ideal indications include: previous decompression for a herniated disc or, previous laminectomy where the patient presents with one-sided radiculopathy requiring revision decompression in association with micro-instability, spondylolisthesis, or degenerative disc disease.

Other Indications for TLIF
Other indications include patients who are at high risk for failed fusion (pseudoarthrosis) due to a previously failed fusion, osteoporosis, medical illnesses, or smoking history. In cases where the patient is at high risk for pseudoarthrosis, interbody fusion would increase the success of the overall fusion construct. In patients who have osteopenic bone and are at risk for kyphosis with a large disc space, load sharing is improved and stress to the pedicle screws is removed by placing an anterior column construct to support the front two-thirds of the vertebral body.

The TLIF procedure is also suitable in cases where an ALIF is not possible either due to previous anterior surgery, significant medical illnesses, obesity, or in a young male who does not want to entertain the risk of retrograde ejaculation.

Bone Grafts and Structural Implants
Various devices can be used as structural grafts: cages to hold bone graft, bone graft extenders, demineralized bone matrix (DBM), biologic substitutes such as bone morphogenetic protein (rhBMP-2), or autogenous bone. The ideal standard of care is to use the patient's own bone harvested at the time of surgery from the iliac crest (autogenous bone), although rhBMP-2 is an attractive alternative to today's standard.

There are several types of structural implants used in interbody fusions. Fibular allografts are implants made from donor leg bones. These implants can be implanted with autogenous bone to titanium cages, carbon-fiber cages, or resorbable cages that can be used as an implant. The cages are filled will bone graft or bone graft substitute to facilitate fusion.

Fusion Techniques
Proper fusion technique is far more important than the distinct implant that is used. Preparation of the vertebral endplates, conforming the endplates to the height and shape of the implant, maximizing the contact surface area for both the graft and the implant all lend to the success of the construct.

TLIF is an efficient means of dealing with several spinal disorders including discogenic disease, degenerative disc height collapse, kyphotic deformities, spondylolisthesis, or other instabilities. TLIF allows the surgeon to provide - with greater certainty, a successful posterior spinal fusion with instrumentation.