TLIF — Transforaminal Lumbar Interbody Fusion

TLIF is a fusion of one or more lumbar segments performed through the back, in which the disc is removed and replaced with a cage — a spacer — placed into the emptied disc space, supported by screws and rods. The word transforaminal describes the route: I approach the disc from one side, through the foramen, the bony window where the nerve exits. This unilateral route is a real advantage, because it lets me reach the disc space and place the cage without having to pull the nerve sac across from both sides, as older techniques required. The cage restores the height of the disc, the screws and rods hold the correction, and bone graft is placed so the segment fuses solidly over the following months.

When I do reconstruct from the back, TLIF is my preferred posterior interbody operation because it is versatile, reliable, and — crucially — it lets me put an interbody cage into the front column of the spine, which is where the shape, the lordosis, is set. This matters because of my central belief: I approach every fusion as a deformity correction. When I fuse a level, I am not just holding it still; I am setting the shape it will hold for life. So I plan the cage position and height to restore the segmental lordosis of that level, and I choose that lordosis with the whole spine in mind — matching it to the person's pelvic shape so that the global sagittal balance is preserved. Getting this right is not a cosmetic nicety. Restoring proper lordosis is what protects the segments above and below from being overloaded, and it is one of the most important things I can do to give a durable result and to reduce the risk of adjacent segment problems down the line.

Placing the cage well forward in the disc space, and using a lordotic or expandable cage where appropriate, allows me to rebuild the forward curve of that segment rather than flatten it. At the same time, TLIF decompresses the nerves in two ways: directly, because I remove bone and disc on the approach side to free the nerve; and indirectly, because restoring the disc height reopens the foramen and takes the pressure off the exiting nerve. So a well-executed TLIF addresses the nerve compression and the alignment together, in one operation, from the back.

For suitable cases I offer TLIF through an endoscopic approach — either a full-endoscopic or a biportal endoscopic technique. The principle here is one I value greatly: low demand, low insult. Instead of a long incision and stripping the muscles off the spine, the endoscopic route works through very small portals, sparing the muscles and soft tissues, with less bleeding and, for many people, a quicker, more comfortable recovery. It is a lower insult to the body for the same fundamental goal. It is not right for every case — larger deformities and certain revisions still need an open approach — and it carries a real learning curve, but for the right, lower-demand case it is a genuinely attractive way to achieve the same fusion with less collateral damage.

TLIF is one of the most studied lumbar fusion techniques and is well supported. Compared with open surgery, minimally invasive TLIF produces less blood loss, shorter hospital stays, reduced painkiller use and lower complication rates, with equivalent medium-term pain and disability scores. Compared with the older posterior interbody technique, PLIF, meta-analyses find similar fusion rates and satisfaction but that TLIF has shorter operating time, less blood loss, and fewer dural tears and nerve-root injuries — because it avoids the bilateral neural retraction. Segmental lordosis restoration depends on cage position and design, which is exactly why I pay it such close attention. Endoscopic TLIF techniques achieve comparable fusion with markedly less tissue disruption, at the cost of longer operating time and a steeper technique.

Recovery is usually steady and, with the minimally invasive and endoscopic approaches, often quicker than people expect. Most people are up and walking the day of or the day after surgery, and go home within a few days. There is a period of some weeks to months during which heavy lifting and twisting are limited while the fusion becomes solid, and physiotherapy supports a graded return to normal activity. The fused level is now stiff, because it is joined, but the rest of the spine continues to move — and if I have restored the alignment well, that stiffness sits within a balanced spine, which is the whole point. The spine is followed up over the longer term.

• —Parker SL, et al. Comparative effectiveness of minimally invasive versus open TLIF: 2-year assessment. (PMID 21336176)
• —Parker SL, et al. MIS versus open TLIF for degenerative spondylolisthesis: comparative effectiveness and cost-utility. (PMID 23321379)
• —Clinical and radiographic comparison of open versus MIS-TLIF with bilateral facetectomies. (PMID 32677520)
• —Comparison of PLIF and TLIF for lumbar degenerative diseases: systematic review and meta-analysis. (PMID 29367001)
• —Improvement of segmental lordosis in TLIF: a comparison of two techniques. (PMC4836934)
• —Massie LW, et al. Expandable cages improve sagittal alignment and outcomes after MIS-TLIF. (PMID 38567017)
• —Assessment of an articulating expandable interbody cage in MIS-TLIF for spondylolisthesis. (PMID 29290133)
• —Heo DH, et al. Fully endoscopic lumbar interbody fusion using a percutaneous biportal technique. (PMID 28760038)
• —Biportal endoscopic TLIF versus PLIF: clinical and radiologic outcomes. (PMID 39609526)
• —Endoscopic-assisted iLIF versus MI-TLIF: systematic review and meta-analysis. (PMID 35136081 / PMC8825843)
• —Endoscopic versus MIS-TLIF: systematic review and meta-analysis. (PMID 38168685 / PMC10821211)
• —Comparison of complication rates of MIS-TLIF and lateral lumbar interbody fusion: systematic review. (PMID 26424344)